US20030194798A1 - Minicell compositions and methods - Google Patents

Abstract

The invention provides compositions and methods for the production of achromosomal and anucleate cells useful for applications such as diagnositic and therapeutic uses, as well as research tools and agents for drug discovery.

Description

FIELD OF THE INVENTION
• The invention is drawn to compositions and methods for the production of achromosomal archeabacterial, eubacterial and anucleate eukaryotic cells that are used as, e.g., therapeutics and/or diagnostics, reagents in drug discovery and functional proteomics, research tools, and in other applications as well.[0001]
BACKGROUND OF THE INVENTION
• The following description of the background of the invention is provided to aid in understanding the invention, but is not admitted to describe or constitute prior art to the invention. The contents of the articles, patents, and patent applications, and all other documents and electronically available information mentioned or cited in this application, are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. Applicants reserve the right to physically incorporate into this application any and all materials and information from any such articles, patents, patent applications, or other documents.[0002]
• Minicells are achromosomal cells that are products of aberrant cell division, and contain RNA and protein, but little or no chromosomal DNA. Clark-Curtiss and Curtiss III, Analysis of Recombinant DNA Using[0003]Escherichia coliMinicells, 101 Methods in Enzymology 347 (1983); Reeve and Mendelson, Minicells ofBacillus subtilis.A new system for transport studies in absence of macromolecular biosynthesis, 352 Biochim. Biophys. Acta 298-305 (1974). Minicells are capable of plasmid-directed synthesis of discrete polypeptides in the absence of synthesis directed by mRNA from the bacterial chromosome. Meagher et al., Protein Expression inE. coliMinicells by Recombinant Plasmids, 10 Cell 521, 523 (1977); Roozen et al., Synthesis of Ribonucleic Acid and Protein in Plasmid-Containing Minicells ofEscherichia coliK-12, 107(1) J. of Bacteriology 21 (1971); and Curtiss III, Research on bacterial conjugation with minicells and minicell-producingE. colistrains, In: Microbial Drug Resistance, Editors Susumu Mitsuhashi & Hajime Hashimoto, p. 169 (Baltimore: University Park Press 1976). Early descriptions of minicells include those of Adler et al., Genetic control of cell division in bacteria, 154 Science 417 (1966), and Adler et al. (MiniatureEscherichia colicells deficient in DNA, 57 Proc. Nat. Acad. Sci (Wash.) 321 (1967)). However, discovery of the production of minicells can arguably be traced to the 1930's (Frazer and Curtiss III, Production, Properties and Utility of Bacterial Minicells, 69 Curr. Top. Microbiol. Immunol. 1-3 (1975)).
• Prokaryotic (a.k.a. eubacterial) minicells have been used to produce various eubacterial proteins. See, e.g., Michael Gaâel, et al., The kdpF Subunit Is Part of the K+-translocating Kdp Complex of[0004]Escherichia coliand Is Responsible for Stabilization of the Complex in vitro, 274(53) Jn. of Biological Chemistry 37901 (1999); Harlow, et al., Cloning and Characterization of the gsk Gene Encoding Guanosine Kinase ofEscherichia coli,177(8) J. of Bacteriology 2236 (1995); Carol L. Pickett, et al., Cloning, Sequencing, and Expression of theEscherichia coliCytolethal Distinding Toxin Genes, 62(3) Infection & Immunity 1046 (1994); Raimund Eck & Jörn Belter, Cloning and characterization of a gene coding for thecatechol 1,2 dioxygenase of Arthrobacter sp. mA3, 123 Gene 87 (1993); Andreas Schlössser, et al, Subcloning, Nucleotide Sequence, and Expression of trkG, a Gene That Encodes an Integral Membrane Protein Involved in Potassium Uptake via the Trk System ofEscherichia coli,173(10) J. of Bacteriology 3170 (1991); Mehrdad Jannatipour, et al., Translocation ofVibrio harveyiN,N′-Diacetylchitobiase to the Outer Membrane ofEscherichia coli169(8) J. of Bacteriology 3785 (1987); and Jacobs et al., Expression ofMycobacterium lepraegenes from a Streptococcus mutans promoter inEscherichia coliK-12, 83(6) Proc. Natl. Acad. Sci. USA 1926 (1986);
• Various bacteria have been used, or proposed to be used, as gene delivery vectors to mammalian cells. For reviews, see Grillot-Courvalin et al., Bacteria as gene delivery vectors for mammalian cells, 10 Current Opinion in Biotechnology 477 (1999); Johnsen et al., Transfer of DNA from Genetically Modified Organisms (GMOs), Biotechnological Institute, 1-70 (2000); Sizemore et al., Attenuated Shigella as a DNA delivery vehicle for DNA-mediated immunization, 270(5234) Science 299 (1995); Patrice Courvalin, et al., Gene transfer from bacteria to mammalian cells, 318 C. R. Acad. Sci. 1207 (1995); Sizemore, et al. Attenuated bacteria as a DNA delivery vehicle for DNA-mediated immunization, 15(8) Vaccine 804 (1997).[0005]
• U.S. Pat. No. 4,190,495, which issued Feb. 26, 1980, to Curtiss is drawn to minicell producing strains of[0006]E. colithat are stated to be useful for the recombinant expression of proteins.
• U.S. Pat. No. 4,311,797, which issued Jan. 19, 1982 to Khachatourians is stated to be drawn to a minicell based vaccine. The vaccine is stated to induce the production of antibodies against enteropathogenic[0007]E. colicells in cattle and is stated to be effective against coliform enteritis.
• Eubacterial minicells expressing immunogens from other prokaryotes have been described. Purcell et al., Molecular cloning and characterization of the 15-kilodalton major immunogen of Treponema pallidum, Infect. Immun. 57:3708, 1989.[0008]
• In “Biotechnology: Promise . . . and Peril” (IDRC Reports 9:4-7, 1980) authors Fleury and Shirkie aver that George Khachatourians at the Unveristy of Saskatchewan, Canada, “is working on a vaccine against cholera using ‘minicells.’” The minciells are said to contain “genes from the pathogenic agent,” and the “pathogen antigens are carried on the surface of the minicells” (p. 5, paragraph brigding the central and right columns).[0009]
• Lundstrom et al., Secretion of Semliki Forest virus membrane glycoprotein E1 from[0010]Bacillus subtilis,Virus Res. 2:69-83, 1985, describe the expression of the E1 protein of the eukaryotic virus, Semliki Forest virus (SFV), in Bacillus minicells. The SFV E1 protein used in these studies is not the native E1 protein. Rather, it is a fusion protein in which the N-terminal signal sequence and C-terminal transmembrane domain have been removed and replaced with signal sequences from a gene fromBacillus amyloliquefaciens.The authors aver that “E1 is properly translocated through the cell membrane and secreted” (p. 81, 1.1. 19-20), and note that “it has been difficult to express viral membrane proteins in prokaryotes” (p. 81, 1. 27).
• U.S. Pat. No. 4,237,224, which issued Dec. 2, 1980, to Cohen and Boyer, describes the expression of[0011]X. LaevisDNA inE. coliminicells.
• U.S. patent application Serial No. 60/293,566 (attorney docket Nos. 078853-0401 and 089608-0201), is entitled “Minicell Compositions and Methods,” and was filed May 24, 2001, by Sabbadini, Roger A., Berkley, Neil L., and Klepper, Robert E., and is hereby incorporated in its entirety by reference.[0012]
• Jespersen et al. describes the use of “proteoliposomes” to generate antibodies to the AMPA receptor. Jespersen L K, Kuusinen A, Orellana A, Keinanen K, Engberg J. Use of proteoliposomes to generate phage antibodies against native AMPA receptor. Eur J Biochem. March 2000 ;267(5):1382-9[0013]
SUMMARY OF THE INVENTION
• The invention is drawn to compositions and methods for the production and use of minicells, including but not limited to eubacterial minicells, in applications such as diagnostics, therapeutics, research, compound screening and drug discovery, as well as agents for the delivery of nucleic acids and other bioactive compounds to cells.[0014]
• Minicells are derivatives of cells that lack chromosomal DNA and which are sometimes referred to as anucleate cells. Because eubacterial and archeabacterial cells, unlike eukaryotic cells, do not have a nucleus (a distinct organelle that contains chromosomes), these non-eukaryotic minicells are more accurately described as being “without chromosomes” or “achromosomal,” as opposed to “anucleate.” Nonetheless, those skilled in the art often use the term “anucleate” when referring to bacterial minicells in addition to other minicells. Accordingly, in the present disclosure, the term “minicells” encompasses derivatives of eubacterial cells that lack a chromosome; derivatives of archeabacterial cells that lack their chromosome(s), and anucleate derivatives of eukaryotic cells. It is understood, however, that some of the relevant art may use the terms “anucleate minicells” or anucleate cells” loosely to refer to any of the preceeding types of minicells.[0015]
• In one aspect, the invention is drawn to a eubacterial minicell comprising a membrane protein that is not naturally found in a prokaryote, i.e., a membrane protein from a eukaryote or an archeabacterium. Such minicells may, but need not, comprise an expression element that encodes and expresses the membrane protein that it comprises. The membrane protein may be one found in any non-eubacterial membrane, including, by way of non-limiting example, a cellular membrane, a nuclear membrane, a nucleolar membrane, a membrane of the endoplasmic reticulum (ER), a membrane of a Golgi body, a membrane of a lysosome a membrane of a peroxisome, a caveolar membrane, an outer membrane of a mitochondrion or a chloroplast, and an inner membrane of a mitochondrion or a chloroplast. By way of non-limiting example, a membrane protein may be a receptor, such as a G-protein coupled receptor; an enzyme, such as ATPase or adenylate cyclase, a cytochrome; a channel; a transporter; or a membrane-bound nucleic acid binding factor, such as a transcription and/or translation factor; signaling components; components of the electon transport chain (ETC); or cellular antigens. A membrane fusion protein, which is generated in vitro using molecular cloning techniques, does not occur in nature and is thus a membrane protein that is not naturally found in a prokaryote, even if the fusion protein is prepared using amino acid sequences derived from eubacterial proteins.[0016]
• Minicells that have segregated from parent cells lack chromosomal and/or nuclear components, but retain the cytoplasm and its contents, including the cellular machinery required for protein expression. Although chromosomes do not segregate into minicells, extrachromosomal and/or episomal genetic expression elements will segregate, or may be introduced into mincells after segregation from parent cells. Thus, in one aspect, the invention is drawn to minicells comprising an expression element, which may be an inducible expression element, that comprises expression sequences operably linked to an open reading frame (ORF) that encodes the non-eubacterial membrane protein. In a related aspect, the invention is drawn to minicell-producing host cells having an expression element, which may be an inducible expression element, that comprises expression sequences operably linked to an ORF that encodes a non-eubacterial membrane protein. In a related aspect, the invention is drawn to a method of making a eubacterial minicell comprising a membrane protein that is not naturally found in a prokaryote, the method comprising growing minicell-producing host cells, the host cells having an expression element, which may be an inducible expression element, that comprises expression sequences operably linked to an ORF that encodes a non-eubacterial membrane protein; and preparing minicells from the host cells. Optionally, at any point in the method, an inducing agent is provided in order to induce expression of an ORF that encodes a non-eubacterial membrane protein.[0017]
• In one aspect, the invention is drawn to display produced membrane-associated protein(s) on the surface of the minicell. For purposes of this document, the term “display” is defined as exposure of the structure of interest on the outer surface of the minicell. By way of non-limiting example, this structure may be an internally expressed membrane protein or chimeric construct to be inserted in or associated with the minicell membrane such that the extracellular domain or domain of interest is exposed on the outer surface of the minicell (expressed and displayed on the surface of the minicell or expressed in the parental cell to be displayed on the surface of the segregated minicell). In any scenario, the “displayed” protein or protein domain is available for interaction with extracellular components. A membrane-associated protein may have more than one extracellular domain, and a minicell of the invention may display more than one membrane-associated protein.[0018]
• A membrane protein displayed by eubacterial minicells may be a receptor. Receptors include, by way of non-limiting example, G-coupled protein receptors, hormone receptors, and growth factor receptors. Minicells displaying a receptor may, but need not, bind ligands of the receptor. In therapeutic applications of this aspect of the invention, the ligand is an undesirable compound that is bound to its receptor and, in some aspects, is internalized or inactivated by the minicells. In drug discovery applications of this aspect of the invention, the ligand for the receptor may be detectably labeled so that its binding to its receptor may be quantified. In the latter circumstance, the minicells may be used to identify and isolate, from a pool of compounds, one or more compounds that inhibit or stimulate the activity of the receptor. That is, these minicells can be used in screening assays, including assays such as those used in high throughput screening (HTS) systems and other drug discovery methods, for the purpose of preparing compounds that influence the activity of a receptor of interest.[0019]
• The displayed domain of a membrane protein may be an enzymatic domain such as on having oxidoreductase, transferase, hydrolase, lyase, isomerase ligase, lipase, kinase, phosphatase, protease, nuclease and/or synthetase activity. Contacting such minicells with the appropriate substrate of the enzyme allows the substrate to be converted to reactant. When either the substrate or reactant is detectable, the reaction catalyzed by the membrane-bound enzyme may be quantified. In the latter instance, the minicells may be used to identify and isolate, from a pool of compounds, one or more compounds that inhibit or stimulate the activity of the enzyme represented by the displayed enzymatic moiety. That is, these minicells can be used in screening assays, including assays such as those used in high throughput screening (HTS) systems and other drug discovery methods, for the purpose of preparing compounds that influence the activity of an enzyme or enzymatic moiety of interest.[0020]
• The membrane protein displayed by minicells may be a fusion protein, i.e., a protein that comprises a first polypeptide having a first amino acid sequence and a second polypeptide having a second amino acid sequence, wherein the first and second amino acid sequences are not naturally present in the same polypeptide. At least one polypeptide in a membrane fusion protein is a “transmembrane domain” or “membrane-anchoring domain”. The transmembrane and membrane-anchoring domains of a membrane fusion protein may be selected from membrane proteins that naturally occur in a eucaryote, such as a fungus, a unicellular eucaryote, a plant and an animal, such as a mammal including a human. Such domains may be from a viral membrane protein naturally found in a virus such as a bacteriophage or a eucaryotic virus, e.g., an adenovirus or a retrovirus. Such domains may be from a membrane protein naturally found in an archaebacterium such as a thermophile.[0021]
• The displayed domain of a membrane fusion protein may be an enzymatic domain such as one having oxidoreductase, transferase, hydrolase, lyase, isomerase ligase, lipase, kinase, phosphatase, protease, nuclease and/or synthetase activity. Contacting such minicells with the appropriate substrate of the enzyme allows the substrate to be converted to reactant. When either the substrate or reactant is detectable, the reaction catalyzed by the membrane-bound enzyme may be quantified. In the latter instance, the minicells may be used to identify and isolate, from a pool of compounds, one or more compounds that inhibit or stimulate the activity of the enzyme represented by the displayed enzymatic moiety. That is, these minicells can be used in screening assays, including assays such as those used in high throughput screening (HTS) systems and other drug discovery methods, for the purpose of preparing compounds that influence the activity of an enzyme or enzymatic moiety of interest.[0022]
• The displayed domain of a membrane fusion protein may be a binding moiety. By way of non-limiting example, binding moieties used for particular purposes may be a binding moiety directed to a compound or moiety displayed by a specific cell type or cells found predominantly in one type of tissue, which may be used to target minicells and their contents to specific cell types or tissues; or a binding moiety that is directed to a compound or moiety displayed by a pathogen, which may be used in diagnostic or therapeutic methods; a binding moiety that is directed to an undesirable compound, such as a toxin, which may be used to bind and preferably internalize and/or neutralize the undesirable compound; a diseased cell; or the binding moiety may be a domain that allows for the minicells to be covalently or non-covalently attached to a support material, which may be used in compositions and methods for compound screening and drug discovery. By “diseased cell” it is meant pathogen-infected cells, malfunctioning cells, and dysfunctional cells, e.g., cancer cells.[0023]
• In various aspects, the minicells of the invention comprise one or more biologically active compounds. The term “biologically active” (synonymous with “bioactive”) indicates that a composition or compound itself has a biological effect, or that it modifies, causes, promotes, enhances, blocks, reduces, limits the production or activity of, or reacts with or binds to an endogenous molecule that has a biological effect. A “biological effect” may be but is not limited to one that stimulates or causes an immunoreactive response; one that impacts a biological process in an animal; one that impacts a biological process in a pathogen or parasite; one that generates or causes to be generated a detectable signal; and the like. Biologically active compositions, complexes or compounds may be used in therapeutic, prophylactic and diagnostic methods and compositions. Biologically active compositions, complexes or compounds act to cause or stimulate a desired effect upon an animal. Non-limiting examples of desired effects include, for example, preventing, treating or curing a disease or condition in an animal suffering therefrom; limiting the growth of or killing a pathogen in an animal infected thereby; augmenting the phenotype or genotype of an animal; stimulating a prophylactic immunoreactive response in an animal; or diagnosing a disease or disorder in an animal.[0024]
• In the context of therapeutic applications of the invention, the term “biologically active” indicates that the composition, complex or compound has an activity that impacts an animal suffering from a disease or disorder in a positive sense and/or impacts a pathogen or parasite in a negative sense. Thus, a biologically active composition, complex or compound may cause or promote a biological or biochemical activity within an animal that is detrimental to the growth and/or maintenance of a pathogen or parasite; or of cells, tissues or organs of an animal that have abnormal growth or biochemical characteristics, such as cancer cells.[0025]
• In the context of diagnostic applications of the invention, the term “biologically active” indicates that the composition, complex or compound can be used for in vivo or ex vivo diagnostic methods and in diagnostic compositions and kits. For diagnostic purposes, a preferred biologically active composition or compound is one that can be detected, typically (but not necessarily) by virtue of comprising a detectable polypeptide. Antibodies to an epitope found on composition or compound may also be used for its detection.[0026]
• In the context of prophylactic applications of the invention, the term “biologically active” indicates that the composition or compound induces or stimluates an immunoreactive response. In some preferred embodiments, the immunoreactive response is designed to be prophylactic, i.e., prevents infection by a pathogen. In other preferred embodiments, the immunoreactive response is designed to cause the immune system of an animal to react to the detriment of cells of an animal, such as cancer cells, that have abnormal growth or biochemical characteristics. In this application of the invention, compositions, complexes or compounds comprising antigens are formulated as a vaccine.[0027]
• It will be understood by those skilled in the art that a given composition, complex or compound may be biologically active in therapeutic, diagnostic and prophylactic applications. A composition, complex or compound that is described as being “biologically active in a cell” is one that has biological activity in vitro (i.e., in a cell culture) or in vivo (i.e., in the cells of an animal). A “biologically active component” of a composition or compound is a portion thereof that is biologically active once it is liberated from the composition or compound. It should be noted, however, that such a component may also be biologically active in the context of the composition or compound.[0028]
• In one aspect, the minicells of the invention comprise a therapeutic agent. Such minicells may be used to deliver therapeutic agents. In a preferred embodiment, a minicell comprising a therapeutic agent displays a binding moiety that specifically binds a ligand present on the surface of a cell, so that the minicells may be “targeted” to the cell. The therapeutic agent may be any type of compound or moiety, including without limitation small molecules, polypeptides, antibodies and antibody derivatives and nucleic acids. The therapeutic agent may be a drug; a prodrug, i.e., a compound that becomes biologically active in vivo after being introduced into a subject in need of treatment; or an immunogen.[0029]
• In one aspect, the minicells of the invention comprise a detectable compound or moiety. As is understood by those of skill in the art, a compound or moiety that is “detectable” produces a signal that can detected by spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radiochemical, or chemical means such as fluorescence, chemifluoresence, or chemiluminescence, electrochemilumenscence, or any other appropriate means. A detectable compound may be a detectable polypeptide, and such polypeptides may, but need not, be incorporated into fusion membrane proteins of the minicell. Detectable polypeptides or amino acid sequences, includes, by way of non-limiting example, a green fluorescent protein (GFP), a luciferase, a beta-galactosidase, a His tag, an epitope, or a biotin-binding protein such as streptavidin or avidin. The detectable compound or moiety may be a radiolabeled compound or a radioisotope. A detectable compound or moiety may be a small molecule such as, by way of non-limiting example, a fluorescent dye; a radioactive iostope; or a compound that may be detected by x-rays or electromagnetic radiation. Image enhancers as those used for CAT and PET scans (e.g., calcium, gallidium) may be used. In another non-limiting example, detectable labels may also include loss of catalytic substrate or gain of catalytic product following catalysis by a minicell displayed, solule cytoplasmic, or secreted enzyme.[0030]
• In one aspect, the invention is drawn to a minicell comprising one or more bioactive nucleic acids or templates thereof. By way of non-limiting example, a bioactive nucleic acid may be an antisense oligonucleotide, an aptamer, an antisense transcript, a ribosomal RNA (rRNA), a transfer RNA (tRNA), a molecular decoy, or an enzymatically active nucleic acid, such as a ribozyme. Such minicells can, but need not, comprise a displayed polypeptide or protein on the surface of the minicell. The displayed polypeptide or protein may be a binding moiety directed to a compound or moiety displayed by a particular type of cell, or to a compound or moiety displayed by a pathogen. Such minicells can further, but need not, comprise an expression element having eubacterial, archael, eucaryotic, or viral expression sequences operably linked to a nucleotide sequence that serves as a template for a bioactive nucleic acid.[0031]
• In one aspect, the invention is drawn to immunogenic minicells, i.e., minicells that display an immunogen, vaccines comprising immunogenic minicells, antibodies and antibody derivatives directed to immunogens displayed on immunogenic minicells, and method of making and using immunogenic minicells and antibodies and antibody derivatives produced therefrom in prophylactic, diagnostic, therapeutic and research applications. A preferred immunogen displayed by a minicell is an immunogenic polypeptide, which is preferably expressed from an expression element contained within the minicell in order to maximize the amount of immunogen displayed by the immunogenic minicells. The immunogenic polypeptide can be derived from any organism, obligate intracelluar parasite, organelle or virus with the provisio that, in prophylactic applications, the immunogenic polypeptide is not derived from a prokaryote, including a eubacterial virus. The source organism for the immunogen may be a pathogen. A minicell displaying an immunogen derived from a pathogen is formulated into a vaccine and, in a prophylactic application, used to treat or prevent diseases and disorders caused by or related to the eukaryotic or archeabacterial pathogen.[0032]
• In a separate aspect, the invention is drawn to minicells that display an immunogen derived from a nonfunctional, dysfunctional and/or diseased cell. By way of non-limiting example, the minicells display an immunogenic polypeptide derived from a hyperproliferative cell, i.e., a cell that is tumorigenic, or part of a tumor or cancer. As another non-limiting example, a cell that is infected with a virus or an obligate intracellular parasite (e.g., Rickettsiae) displays an immunogenic polypeptide that is encoded by the genome of the infected cell but is aberrenatly expressed in an infected cell. A vaccine comprising a minicell displaying an immunogen derived from a nonfunctional, dysfunctional and/or diseased cell is used in methods of treating or preventing hyperproliferative diseases or disorders, including without limitation a cell comprising an intracellular pathogen.[0033]
• In one aspect, the invention is drawn to methods of using minicells, and expression systems optimized therefore, to manufacture, on a large scale, proteins using recombinant DNA technology. In a related aspect, the invention is drawn to the production, via recombinant DNA technology, and/or segration of exogenous proteins in minicells. The minicells are enriched for the exogenous protein, which is desirable for increased yield and purity of the protein. In addition to protein purification, the minicells can be used for crystallography, the study of intracellular or extracellular protein-protein interactions, the study of intracellular or extracellular protein-nucleic acid interactions, the study of intracellular or extracellular protein-membrane interactions, and the study of other biological, chemical, or physiological event(s).[0034]
• In one aspect, the invention is drawn to minicells having a membrane protein that has an intracellular domain. By way of non-limiting example, the intracellular domain is exposed on the inner surface of the minicell membrane oriented towards the cytoplasmic compartment. The intracellular protein domain is available for interaction with intracellular components. Intracellular components may be naturally present in the minicells or their parent cells, or may be introduced into minicells after segregation from parent cells. A membrane-associated protein may have more than one intracellular domain, and a minicell of the invention may display more than one membrane-associated protein.[0035]
• In one aspect, the invention is drawn to a minicell comprising a membrane protein that is linked to a conjugatable compound (a.k.a. “attachable compound”). The conjugatable compound may be of any chemical nature and have one or more therapeutic or detectable moities. By way of non-limiting example, a protein having a transmembrane or membrane anchoring domain is displayed and has the capacity to be specifically cross-linked on its extracellular domain. Through this approach, any conjugatable compound of interest may be quickly and easily attached to the outer surface of minicells containing this expressed membrane-spanning domain. In aspects of the invention wherein minicells are used for drug delivery in vivo, a preferred conjugatable compound is polyethylene glycol (PEG), which provides for “stealth” minicells that are not taken as well and/or as quickly by the reticuloendothelial system (RES). Other conjugatable compounds include polysaccharides, polynucleotides, lipopolysaccharides, lipoproteins, glycosylated proteins, synthetic chemical compounds, and/or chimeric combinations of these examples listed.[0036]
• In various aspects of the invention, the minicell displays a polypeptide or other compound or moiety on its surface. By way of non-limiting example, a non-eubacterial membrane protein displayed by eubacterial minicells may be a receptor. Minicells displaying a receptor may, but need not, bind ligands of the receptor. In therapeutic applications of this aspect of the invention, the ligand is an undesirable compound that is bound to its receptor and, in some aspects, is internalized by the minicells. In drug discovery applications of this aspect of the invention, the ligand for the receptor may be detectably labeled so that its binding to its receptor may be quantified. In the latter circumstance, the minicells may be used to identify and isolate, from a pool of compounds, one or more compounds that inhibit or stimulate the activity of the receptor. That is, these minicells can be used in screening assays, including assays such as those used in high throughput screening (HTS) systems and other drug discovery methods, for the purpose of preparing compounds that influence the activity of a receptor of interest.[0037]
• The non-eubacterial membrane protein displayed by minicells may be a fusion protein, i.e., a protein that comprises a first polypeptide having a first amino acid sequence and a second polypeptide having a second amino acid sequence, wherein the first and second amino acid sequences are not naturally present in the same polypeptide. At least one polypeptide in a membrane fusion protein is a “transmembrane domain” or “membrane-anchoring domain”. The transmembrane and membrane-anchoring domains of a membrane fusion protein may be selected from membrane proteins that naturally occur in a eukaryote, such as a fungus, a unicellular eukaryote, a plant and an animal, such as a mammal including a human. Such domains may be from a viral membrane protein naturally found in a virus such as a bacteriophage or a eukaryotic virus, e.g., an adenovirus or a retrovirus. Such domains may be from a membrane protein naturally found in an archaebacterium such as a thermophile.[0038]
• The displayed domain of a membrane fusion protein may be an enzymatic domain such as one having the activity of a lipase, a kinase, a phosphatase, a reductase, a protease, or a nuclease. Contacting such minicells with the appropriate substrate of the enzyme allows the substrate to be converted to reactant. When either the substrate or reactant is detectable, the reaction catalyzed by the membrane-bound enzyme may be quantified. In the latter instance, the minicells may be used to identify and isolate, from a pool of compounds, one or more compounds that inhibit or stimulate the activity of the enzyme represented by the displayed enzymatic moiety. That is, these minicells can be used in screening assays, including assays such as those used in high throughput screening (HTS) systems and other drug discovery methods, for the purpose of preparing compounds that influence the activity of an enzyme or enzymatic moiety of interest.[0039]
• The displayed domain of a membrane fusion protein may be a binding moiety. By way of non-limiting example, binding moieties used for particular purposes may be a binding moiety directed to a compound or moiety displayed by a specific cell type or cells found predominantly in one type of tissue, which may be used to target minicells and their contents to specific cell types or tissues; or a binding moiety that is directed to a compound or moiety displayed by a pathogen, which may be used in diagnostic or therapeutic methods; a binding moiety that is directed to an undesirable compound, such as a toxin, which may be used to bind and preferably internalize and/or neutralize the undesirable compound; a diseased cell; or the binding moiety may be a domain that allows for the minicells to be covalently or non-covalently attached to a support material, which may be used in compositions and methods for compound screening and drug discovery.[0040]
• In one aspect, the invection provides compositions and methods for preparing a soluble and/or secreted protein where the protein remains in the cytoplasm of the minicell or is secreted following native secretory pathways for endogenous screted proteins or is secreted using chimeric fusion to secretory signaling sequences. By way of non-limiting example, secreted or cytoplasmic soluble proteins may be produced for purification, targeted therapeutic applications where the protein produced is a therapeutic agent and is produced at the desired site of, detection for screening or diagnostic purposes where the protein is produced in response to a simulous and/or localization event, or to stimulate targeted minicell-cell fusion or interaction events where the protein produced stimulates cell-cell fusion upon targeted stimulation.[0041]
• In one aspect, the invention provides compositions and methods for preparing antibodies and/or antibody derivatives that recognize an immunogenic epitope present on the native form of a membrane protein, but which is not immunogenic when the membrane protein is denatured or when prepared as a synthetic oligopeptide. Such antibodies and antibody derivatives are said to be “conformation sensitive.” Unlike most antibodies and antibody derivatives prepared by using a denatured membrane protein or an oligopeptide derived from the membrane protein, conformation sensitive antibodies and antibody derivatives specifically bind membrane proteins in their native state (i.e., in a membrane) with high affinity. Conformation sensitive antibodies and antibody derivatives are used to target compounds and compositions, including a minicell of the invention, to a cell displaying the membrane protein of choice. Conformation sensitive antibodies and antibody derivatives are also used to prevent receptors from binding their natural ligands by specifically binding to the receptor with a high affinity and thereby limiting access of the ligand to the receptor. Conformation sensitive antibodies and antibody derivatives can be prepared that are specific for a specific isoform or mutant of a membrane protein, which can be useful in research and medical applications.[0042]
• In one aspect, the invention provides biosensors comprising minicells including, not limited to, the minicells of the invention. An exemplary biosensor of the invention is a BlAcore chip, i.e., a chip onto which minicells are attached, where the minicells undergo some change upon exposure to a preselected compound, and the change is detected using surface plasmon resonance. A biosensor comprising minicells can be used in methods of detecting the presence of an undesirable compound. Undesirable compounds include but are not limited to, toxins; pollutants; explosives, such as those in landmines or illegally present; illegal narcotics; components of biological or chemical weapons. In a related aspect, the invention provides a device comprising a microchip operatively associated with a biosensor comprising a minicell. The device can further comprise an actuator that performs a responsive function when the sensor detects a preselected level of a marker.[0043]
• In one aspect, the invention provides minicells that may be used as research tools and/or kits comprising such research tools. The minicells of the invention may be used as is, or incorporated into research tools useful for scientific research regarding all amino acid comprising compounds including, but not limited to membrane-associated proteins, chimeric membrane fusion proteins, and soluble proteins. Such scientific research includes, by way of non-limiting example, basic research, as well as pharmacological, diagnostic, and pharmacogenetic studies. Such studies may be carried out in vivo or in vitro.[0044]
• In one aspect, the invention is drawn to archaebacterial minicells. In a related aspect, the invention is drawn to archaebacterial minicells comprising at least one exogenous protein, that is, a protein that is not normally found in the parent cell, including without limitation fusion proteins. The archaebacterial minicells of the invention optionally comprise an expression element that directs the production of the exogenous protein(s).[0045]
• In other aspects, the invention is drawn to methods of preparing the minicells, protoplasts, and poroplasts™ of the invention for various applications including but not limited to diagnostic, therapeutic, research and screening applications. In a related aspect, the invention is drawn to pharmaceutical compositions, reagents and kits comprising minicells.[0046]
• In each aspect and embodiment of the invention, unless stated otherwise, embodiments wherein the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast exist.[0047]
• In a first aspect, the invention provides a minicell comprising a membrane protein selected from the group consisting of a eukaryotic membrane protein, an archeabacterial membrane protein and an organellar membrane protein. In another embodiment, wherein the minicell comprises a biologically active compound. By way of non-limiting example, the biologically active compound is a radioisotope, a polypeptide, a nucleic acid or a small molecule.[0048]
• In another embodiment, the minicell comprises a expression construct, wherein the first expression construct comprises expression sequences operably linked to an ORF that encodes a protein. In another embodiment, the ORF encodes the membrane protein. In another embodiment, the expression sequences that are operably linked to an ORF are inducible and/or repressible.[0049]
• In another aspect, the minicell comprises a second expression construct, wherein the second expression construct comprises expression sequences operably linked to a gene. In another embodiment, the expression sequences that are operably linked to a gene are inducible and/or repressible. In a related embodiment, the gene product of the gene regulates the expression of the ORF that encodes the protein. A factor that “regulates” the expression of a gene or a gene product directly or indirectly initiates, enhances, quickens, slows, terminates, limits or completely blocks expression of a gene. In different embodiments, the gene product of the gene is a nucleic acid or a polypeptide. The polypeptide can be of any type, including but not limited to a membrane protein, a soluble protein or a secreted protein. A membrane protein can be a membrane fusion protein comprising a first polypeptide, which comprises at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide.[0050]
• In one aspect, the invention provides a minicell comprising a membrane fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein and is neither a His tag nor a glutathione-S-transferase polypeptide. In various embodiments, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the minicell comprises a biologically active compound.[0051]
• In one aspect, the invention provides a minicell comprising a membrane conjugate, wherein the membrane conjugate comprises a membrane protein chemically linked to a conjugated compound. In one embodiment, the conjugated compound is selected from the group consisting of a nucleic acid, a polypeptide, a lipid and a small molecule.[0052]
• In one aspect, the invention provides a method for making minicells, comprising (a) culturing a minicell-producing parent cell, wherein the parent cell comprises an expression construct, wherein the expression construct comprises a gene operably linked to expression sequences that are inducible and/or repressible, and wherein induction or repression of the gene causes or enhances the production of minicells; and (b) separating the minicells from the parent cell, thereby generating a composition comprising minicells, wherein an inducer or repressor is present within the parent cells during one or more steps and/or between two or more steps of the method. In one embodiment, the method further comprises (c) purifying the minicells from the composition.[0053]
• Relevant gene products are factors involved in or modulating DNA replication, cellular division, cellular partitioning, septation, transcription, translation, or protein folding. The minicells are separated from parent cells by processes such as centrifugation, ultracentrifugation, density gradation, immunoaffinity, immunoprecipitation and other techniques described herein.[0054]
• In one embodiment, the minicell is a poroplast, and the method further comprises (d) treating the minicells with an agent, or incubating the minicells under a set of conditions, that degrades the outer membrane of the minicell. The outer membrane is degraded by treatment with an agent selected from the group consisting of EDTA, EGTA, lactic acid, citric acid, gluconic acid, tartaric acid, polyethyleneimine, polycationic peptides, cationic leukocyte peptides, aminoglycosides, aminoglycosides, protamine, insect cecropins, reptilian magainins, polymers of basic amino acids, polymixin B, chloroform, nitrilotriacetic acid and sodium hexametaphosphate; by exposure to conditions selected from the group consisting of osmotic shock and insonation; and by other methods described herein.[0055]
• In one embodiment, further comprising removing one or more contaminants from the composition. Representative contaminants are LPS and peptidoglycan. In a representative embodiment, LPS is removed by contacting the composition to an agent that binds or degrades LPS. At least about 50%, preferably about 65% to about 75%, more preferably 95%, most preferably 99% or >99% of LPS is removed from an initial preparation of minicells. In a related embodiment, the minicell-producing parent cell comprises a mutation in a gene required for lipopolysaccharide synthesis.[0056]
• In on embodiment, the minicell is a spheroplast, and the method further comprises (d) treating the minicells with an agent, or incubating the minicells under a set of conditions, that disrupts or degrades the outer membrane; and (e) treating the minicells with an agent, or incubating the minicells under a set of conditions, that disrupts or degrades the cell wall. The agent that disrupts or degrades the cell wall can be. e.g., a lysozyme, and the set of conditions that disrupts or degrades the cell wall can be, e.g., incubation in a hypertonic solution.[0057]
• In one embodiment, the minicell is a protoplast, and the method further comprises (d treating the minicells with an agent, or incubating the minicells under a set of conditions, that disrupt or degrade the outer membrane; (e) treating the minicells with an agent, or incubating the minicells under a set of conditions, that disrupts or degrades the cell wall, in order to generate a composition that comprises protoplasts; and (f) purifying protoplasts from the composition. In one embodiment, the method further comprises preparing a denuded minicell from the minicell. In one embodiment, the method further comprises covalently or non-covalently linking one or more components of the minicell to a conjugated moiety.[0058]
• In one aspect, the invention provides a L-form minicell comprising (a) culturing an L-form eubacterium, wherein the eubacterium comprises one or more of the following: (i) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of the gene regulates the copy number of an episomal expression construct; (ii) a mutation in an endogenous gene, wherein the mutation regulates the copy number of an episomal expression construct; (iii) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of the gene causes or enhances the production of minicells; and (iv) a mutation in an endogenous gene, wherein the mutation causes or enhances minicell production; (b) culturing the L-form minicell-producing parent cell in media under conditions wherein minicells are produced; and (c) separating the minicells from the parent cell, thereby generating a composition comprising L-form minicells, wherein an inducer or repressor is present within the minicells during one or more steps and/or between two or more steps of the method. In one embodiment, the method further comprises (d) purifying the L-form minicells from the composition.[0059]
• In one aspect, the invention provides a method of producing a protein, comprising (a) transforming a minicell-producing parent cell with an expression element that comprises expression sequences operably linked to a nucleic acid having an ORF that encodes the protein; (b) culturing the minicell-producing parent cell under conditions wherein minicells are produced; and (c) purifying minicells from the parent cell, (d) purifying the protein from the minicells, wherein the ORF is expressed during step (b), between steps (b) and (c), and during step (c).[0060]
• In one embodiment, the expression elements segregate into the minicells, and the ORF is expressed between steps (c) and (d). In one embodiment, the protein is a soluble protein contained within the minicells, and the method further comprises (e) lysing the minicells.[0061]
• In one embodiment, the protein is a secreted protein, and the method further comprises (e) collecting a composition in which the minicells are suspended or with which the minicells are in contact.[0062]
• In one embodiment, the expression sequences to which the ORF is operably linked are inducible, wherein the method further comprises adding an inducing agent between steps (a) and (b); during step (b); and between steps (b) and (c).[0063]
• In one embodiment, the expression sequences to which the ORF is operably linked are inducible, wherein the expression elements segregate into the minicells, the method further comprises adding an inducing agent after step (c).[0064]
• In one embodiment, the method further comprises (e) preparing poroplasts from the minicells, wherein the ORF is expressed during step (b); between steps (b) and (c); during step (c); between step (c) and step (d) when the expression elements segregate into the minicells; and/or after step (d) when the expression elements segregate into the minicells.[0065]
• In one embodiment, the method further comprises (f) purifying the protein from the poroplasts.[0066]
• In one embodiment, the method further comprises (e) preparing spheroplasts from the minicells, wherein the ORF is expressed during step (b), between steps (b) and (c), during step (c), between steps (c) and (d) and/or after step (d).[0067]
• In one embodiment, the method further comprises (f) purifying the protein from the spheroplasts.[0068]
• In one embodiment, the method further comprises (e) preparing protoplasts from the minicells, wherein the ORF is expressed during step (b), between steps (b) and (c), during step (c), between steps (c) and (d) and/or after step (d).[0069]
• In one embodiment, the method further comprises (f) purifying the protein from the protoplasts.[0070]
• In one embodiment, the method further comprises (e) preparing membrane preparations from the minicells, wherein the ORF is expressed during step (b), between steps (b) and (c), during step (c), between steps (c) and (d) and/or after step (d).[0071]
• In one embodiment, the method further comprises (f) purifying the protein from the membrane preparations.[0072]
• In one embodiment, the minicell-producing parent cell is an L-form bacterium.[0073]
• In one aspect, the invention provides a method of producing a protein, comprising (a) transforming a minicell with an expression element that comprises expression sequences operably linked to a nucleic acid having an ORF that encodes the protein; and (b) incubating the minicells under conditions wherein the ORF is expressed.[0074]
• In one embodiment, the method further comprises (c) purifying the protein from the minicells.[0075]
• In one aspect, the invention provides a method of producing a protein, comprising (a) transforming a minicell-producing parent cell with an expression element that comprises expression sequences operably linked to a nucleic acid having an ORF that encodes a fusion protein comprising the protein and a polypeptide, wherein a protease-sensitive amino acid sequence is positioned between the protein and the polypeptide; (b) culturing the minicell-producing parent cell under conditions wherein minicells are produced; (c) purifying minicells from the parent cell, wherein the ORF is expressed during step (b); between steps (b) and (c); and/or after step (c) when the expression elements segregate into the minicells; and (d) treating the minicells with a protease that cleaves the sensitive amino acid sequence, thereby separating the protein from the polypeptide.[0076]
• In one aspect, the invention provides a poroplast, the poroplast comprising a vesicle, bonded by a membrane, wherein the membrane is an eubacterial inner membrane, wherein the vesicle is surrounded by a eubacterial cell wall, and wherein the eubacterial inner membrane is accessible to a compound in solution with the poroplast. In one embodiment, the poroplast is a cellular poroplast. The compound has a molecular weight of at least 1 kD, preferably at least about 0.1 to about 1 kD, more preferably from about 1, 10 or 25 kD to about 50 kD, and most preferably from about 75 or about 100 kD to about 150 or 300 kD.[0077]
• In one embodiment, the poroplast comprises an exogenous nucleic acid, which may be an expression construct. In one embodiment, the expression construct comprises an ORF that encodes an exogenous protein, wherein the ORF is operably linked to expression sequences. In one embodiment, the exogenous protein is a fusion protein, a soluble protein or a secreted protein. In one embodiment, the exogenous protein is a membrane protein, and is preferably accessible to compounds in solution with the poroplast. In one embodiment, poroplasts are placed in a hypertonic solution, wherein 90% or more of an equivalent amount of spheroplasts or protoplasts lyse in the solution under the same conditions.[0078]
• In one embodiment, the membrane protein is selected from the group consisting of a eukaryotic membrane protein, an archeabacterial membrane protein, and an organellar membrane protein. In one embodiment, the membrane protein is a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide is displayed by the poroplast. In one embodiment, the second polypeptide is displayed on the external side of the eubacterial inner membrane. The second polypeptide can be an enzyme moiety, a binding moiety, a toxin, a cellular uptake sequence, an epitope, a detectable polypeptide, and a polypeptide comprising a conjugatable moiety. An enzyme moiety is a polypeptide derived from, by way of non-limiting example, a cytochrome P450, an oxidoreductase, a transferase, a hydrolase, a lyase, an isomerase, a ligase or a synthetase.[0079]
• In one embodiment, the poroplast comprises a membrane component that is chemically linked to a conjugated compound.[0080]
• In one embodiment, the expression construct comprises one or more DNA fragments from a genome or cDNA. In one embodiment, the exogenous protein has a primary amino acid sequence predicted from a nucleic acid sequence.[0081]
• In one aspect, the invention provides a solid support comprising a minicell. In various embodiments, the solid support is a dipstick, a bead or a mictrotiter multiwell plate. In one embodiment, the minicell comprises a detectable compound, which may be a colorimetric, fluorescent or radioactive compound.[0082]
• In one embodiment, the minicell displays a membrane component selected from the group consisting of (i) a eukaryotic membrane protein, (ii) an archeabacterial membrane protein, (iii) an organellar membrane protein, (iv) a fusion protein comprising at least one transmembrane domain or at least one membrane anchoring domain, and (v) a membrane conjugate comprising a membrane component chemically linked to a conjugated compound.[0083]
• In one embodiment, the membrane component is a receptor. In a related embodiment, the solid support further comprises a co-receptor. In one embodiment, the minicell displays a binding moiety.[0084]
• In one aspect, the invention provides a solid support comprising a minicell, wherein the minicell displays a fusion protein, the fusion protein comprising a first polypeptide that comprises at least one transmembrane domain or at least one membrane anchoring domain, and a second polypeptide. In various embodiments, the second polypeptide comprises a binding moiety or an enzyme moiety.[0085]
• In one aspect, the invention provides a solid support comprising a minicell, wherein the minicell comprises a membrane conjugate comprising a membrane component chemically linked to a conjugated compound. In one embodiment, the conjugated compound is a spacer. In one embodiment, the spacer is covalently linked to the solid support. In one embodiment, the conjugated compound is covalently linked to the solid support.[0086]
• In one aspect, the invention provides a minicell comprising a biologically active compound, wherein the minicell displays a ligand or binding moiety, wherein the ligand or binding moiety is part of a fusion protein comprising a first polypeptide that comprises at least one transmembrane domain or at least one membrane anchoring domain and a second polypeptide that comprises a binding moiety, and the minicell is a poroplast, spheroplast or protoplast.[0087]
• In one aspect, the invention provides a eubacterial minicell comprising a biologically active compound, wherein the minicell displays a binding moiety, wherein the binding moiety is selected from the group consisting of (a) a eukaryotic membrane protein; (b) an archeabacterial membrane protein; (c) an organellar membrane protein; and (d) a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein and is neither a His tag nor a glutathione-S-transferase polypeptide, and wherein the polypeptide comprises a binding moiety.[0088]
• In one embodiment, the binding moiety is selected from the group consisting of an antibody, an antibody derivative, a receptor and an active site of a non-catalytic derivative of an enzyme. In a preferred embodiment, the binding moiety is a single-chain antibody. In one embodiment, one of the ORFs encodes a protein that comprises the binding moiety.[0089]
• In one embodiment, the binding moiety is directed to a ligand selected from the group consisting of an epitope displayed on a pathogen, an epitope displayed on an infected cell and an epitope displayed on a hyperproliferative cell.[0090]
• In one embodiment, the invention further comprises a first and second nucleic acid, wherein the first nucleic acid comprises eukaryotic expression sequences operably linked to a first ORF, and a second nucleic acid, wherein the second nucleic acid comprises eubacterial expression sequences operably linked to a second ORF.[0091]
• In one embodiment, the eubacterial expression sequences are induced and/or derepressed when the binding moiety is in contact with a target cell. In a variant embodiment, the eukaryotic expression sequences are induced and/or derepressed when the nucleic acid is in the cytoplasm of a eukaryotic cell. In related embodiments, the protein encoded by the first ORF comprises eukaryotic secretion sequences and/or the protein encoded by the second ORF comprises eubacterial secretion sequences.[0092]
• In one aspect, the invention provides a method of associating a radioactive compound with a cell, wherein the cell displays a ligand specifically recognized by a binding moiety, comprising contacting the cell with a minicell that comprises the radioactive compound and displays the binding moiety. In a diagnostic embodiment, the amount of radiation emitted by the radioactive isotope is sufficient to be detectable. In a therapeutic embodiment, the amount of radiation emitted by the radioactive isotope is sufficient to be cytotoxic. In one embodiment, the ligand displayed by the cell is selected from the group consisting of an epitope displayed on a pathogen, an epitope displayed on an infected cell and an epitope displayed on a hyperproliferative cell. In one embodiment, the binding moiety is selected from the group consisting of an antibody, an antibody derivative, a channel protein and a receptor, and is preferably a single-chain antibody. In other embodiments, the binding moiety is an aptamer or a small molecule. In one embodiment, the ligand is selected from the group consisting of a cytokine, hormone, and a small molecule.[0093]
• In one aspect, the invention provides a method of delivering a biologically active compound to a cell, wherein the cell displays a ligand specifically recognized by a binding moiety, comprising contacting the cell with a minicell that displays the binding moiety, wherein the minicell comprises the biologically active compound, and wherein the contents of the minicell are delivered into the cell from a minicell bound to the cell. In one embodiment, the biologically active compound is selected from the group consisting of a nucleic acid, a lipid, a polypeptide, a radioactive compound, an ion and a small molecule.[0094]
• In one embodiment, the membrane of the minicell comprises a system for transferring a molecule from the interior of a minicell into the cytoplasm of the cell. A representative system for transferring a molecule from the interior of a minicell into the cytoplasm of the cell is a Type III secretion system.[0095]
• In one embodiment, the minicell further comprises a first and second nucleic acid, wherein the first nucleic acid comprises eukaryotic expression sequences operably linked to a first ORF, and a second nucleic acid, wherein the second nucleic acid comprises eubacterial expression sequences operably linked to a second ORF. In one embodiment, one of the ORFs encodes a protein that comprises the binding moiety. In one embodiment, the eubacterial expression sequences are induced and/or derepressed when the binding moiety is in contact with a target cell. In one embodiment, the eukaryotic expression sequences are induced and/or derepressed when the nucleic acid is in the cytoplasm of a eukaryotic cell. In one embodiment, the protein encoded by the first ORF comprises eukaryotic secretion sequences and/or the protein encoded by the second ORF comprises eubacterial secretion sequences. In one embodiment, the ligand is selected from the group consisting of a cytokine, hormone, and a small molecule.[0096]
• In one aspect, the invention provides a minicell displaying a synthetic linking moiety, wherein the synthetic linking moiety is covalenty or non-covalently attached to a membrane component of the mincell.[0097]
• In one aspect, the invention provides a sterically stabilized minicell comprising a displayed moiety that has a longer half-life in vivo than a wild-type minicell, wherein the displayed moiety is a hydrophilic polymer that comprises a PEG moiety, a carboxylic group of a polyalkylene glycol or PEG stearate.[0098]
• In one aspect, the invention provides a minicell having a membrane comprising an exogenous lipid, wherein a minicell comprising the exogenous lipid has a longer half-life in vivo than a minicell lacking the exogenous lipid, and wherein the minicell is selected from the group consisting of a eubacterial minicell, a poroplast, a spheroplast and a protoplast. In one embodiment, the exogenous lipid is a derivitized lipid which may, by way of non-limiting example, be phosphatidylethanolamine derivatized with PEG, DSPE-PEG, PEG stearate; PEG-derivatized phospholipids, a PEG ceramide or DSPE-PEG.[0099]
• In one embodiment, the exogenous lipid is not present in a wild-type membrane, or is present in a different proportion than is found in minicells comprising a wild-type membrane. The exogenous lipid can be a ganglioside, sphingomyelin, monosialoganglioside GM1, galactocerebroside sulfate, 1,2-sn-dimyristoylphosphatidylcholine, phosphatidylinositol and cardiolipin.[0100]
• In one embodiment, the linking moiety is non-covalently attached to the minicell. In one embodiment, one of the linking moiety and the membrane component comprises biotin, and the other comprises avidin or streptavidin. In one embodiment, the synthetic linking moiety is a cross-linker. In one embodiment, the cross-linker is a bifunctional cross-linker.[0101]
• In one aspect, the invention provides a method of transferring a membrane protein from a minicell membrane to a biological membrane comprising contacting a minicell to the biological membrane, wherein the minicell membrane comprises the membrane protein, and allowing the mincell and the biological membrane to remain in contact for a period of time sufficient for the transfer to occur.[0102]
• In one embodiment, the biological membrane is a cytoplasmic membrane or an organellar membrane. In one embodiment, the biological membrane is a membrane selected from the group consisting of a membrane of a pathogen, a membrane of an infected cell and a membrane of a hyperproliferative cell. In one embodiment, the biological membrane is the cytoplasmic membrane of a recipient cell, which may be a cultured cell and a cell within an organism. In one embodiment, the biological membrane is present on a cell that has been removed from an animal, the contacting occurs in vitro, after which the cell is returned to the organism.[0103]
• In one embodiment, the membrane protein is an enzyme. In this embodiment, the membrane protein having enzymatic activity is selected from the group consisting of a cytochrome P450 and a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one polypeptide, wherein the second polypeptide has enzymatic acitivity.[0104]
• In one embodiment, the membrane protein is a membrane fusion protein, the membrane fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide.[0105]
• In one embodiment, the second polypeptide is a biologically active polypeptide. In one embodiment, the minicell displays ligand or a binding moiety.[0106]
• In one aspect, the invention provides a minicell that comprises an expression construct comprising an ORF encoding a membrane protein operably linked to expression sequences, wherein the expression sequences are induced and/or derepressed when the minicell is in contact with a target cell.[0107]
• In one embodiment, the biological membrane is a cytoplasmic membrane or an organellar membrane. In one embodiment, the biological membrane is a membrane selected from the group consisting of a membrane of a pathogen, a membrane of an infected cell and a membrane of a hyperproliferative cell. In one embodiment, the minicell displays a ligand or a binding moiety selected from the group consisting of an antibody, an antibody derivative, an aptamer and a small molecule. In one embodiment, the membrane protein is a membrane fusion protein, the membrane fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide. In one embodiment, the ligand is selected from the group consisting of a cytokine, hormone, and a small molecule.[0108]
• In one aspect, the invention provides a pharmaceutical composition comprising a minicell, wherein the minicell displays a membrane protein, wherein the membrane protein is selected from the group consisting of a eukaryotic membrane protein, an archeabacterial membrane protein and an organellar membrane protein. In one embodiment, the membrane protein is selected from the group consisting of a receptor, a channel protein, a cellular adhesion factor and an integrin. In one embodiment, the pharmaceutical formulation further comprises an adjuvant. In one embodiment, the membrane protein comprises a polypeptide epitope displayed by a hyperproliferative cell. In one embodiment, the membrane protein comprises an epitope displayed by a eukaryotic pathogen, an archeabacterial pathogen, a virus or an infected cell.[0109]
• In one aspect, the invention provides a pharmaceutical composition comprising a minicell, wherein the minicell displays a membrane protein that is a fusion protein, the fusion protein comprising (i) a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and (ii) a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein. In one embodiment, the pharmaceutical formulation further comprises an adjuvant. In one embodiment, the second polypeptide comprises a polypeptide epitope displayed by a hyperproliferative cell. In one embodiment, the membrane protein comprises an epitope displayed by a eukaryotic pathogen, an archeabacterial pathogen, a virus or an infected cell.[0110]
• In one aspect, the invention provides a pharmaceutical composition comprising a minicell, wherein the minicell displays a membrane conjugate, wherein the membrane conjugate comprises a membrane component chemically linked to a conjugated compound. In one embodiment, the membrane protein is selected from the group consisting of a receptor, a channel protein, a cellular adhesion factor and an integrin. In one embodiment, the pharmaceutical further comprises an adjuvant. In one embodiment, the membrane component is a polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain, or a lipid that is part of a membrane. In one embodiment, the conjugated compound is a polypeptide, and the chemical linkage between the membrane compound and the conjugated compound is not a peptide bond. In one embodiment, the conjugated compound is a nucleic acid. In one embodiment, the conjugated compound is an organic compound. In one embodiment, the organic compound is selected from the group consisting of a narcotic, a toxin, a venom, a sphingolipid and a soluble protein.[0111]
• In one aspect, the invention provides a method of making a pharmaceutical composition comprising a minicell, wherein the minicell displays a membrane protein, wherein the membrane protein is selected from the group consisting of a eukaryotic membrane protein, an archeabacterial membrane protein and an organellar membrane protein. In one embodiment, the method further comprises adding an adjuvant to the pharmaceutical formulation. In one embodiment, the method further comprises desiccating the formulation. In one embodiment, the method further comprises adding a suspension buffer to the formulation. In one embodiment, the method further comprises making a chemical modification of the membrane protein. In one embodiment, the chemical modification is selected from the group consisting of glycosylation, deglycosylation, phosphorylation, dephosphorylation and proteolysis. In one aspect, the invention provides a method of making a pharmaceutical composition comprising a minicell, wherein the minicell displays a membrane protein that is a fusion protein, the fusion protein comprising (i) a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and (ii) a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein.[0112]
• In one aspect, the invention provides a method of making a pharmaceutical formulation comprising a minicell, wherein the minicell displays a membrane conjugate, wherein the membrane conjugate comprises a membrane component chemically linked to a conjugated compound. In one embodiment, the method further comprises adding an adjuvant to the pharmaceutical formulation. In one embodiment, the membrane component is a polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain, or a lipid that is part of a membrane. In one embodiment, the conjugated compound is a polypeptide, and the chemical linkage between the membrane compound and the conjugated compound is not a peptide bond. In one embodiment, the conjugated compound is a nucleic acid. In one embodiment, the conjugated compound is an organic compound. In one embodiment, the organic compound is selected from the group consisting of a narcotic, a toxin, a venom, and a sphingolipid.[0113]
• In one aspect, the invention provides a method of detecting an agent that is specifically bound by a binding moiety, comprising contacting a minicell displaying the binding moiety with a composition known or suspected to contain the agent, and detecting a signal that is modulated by the binding of the agent to the binding moiety. In one embodiment, the agent is associated with a disease. In one embodiment, the minicell comprises a detectable compound. In one embodiment, the binding moiety is antibody or antibody derivative. In one embodiment, the composition is an environmental sample. In one embodiment, the composition is a biological sample. In one embodiment, the biological sample is selected from the group consisting of blood, serum, plasma, urine, saliva, a biopsy sample, feces and a skin patch.[0114]
• In one aspect, the invention provides a method of in situ imaging of a tissue or organ, comprising administering to an organism a minicell comprising an imaging agent and a binding moiety and detecting the imaging agent in the organism.[0115]
• In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the binding moiety is an antibody or antibody derivative. In one embodiment, the binding moiety specifically binds a cell surface antigen. In one embodiment, the cell surface antigen is an antigen displayed by a tumorigenic cell, a cancer cell, and an infected cell. In one embodiment, the cell surface antigen is a tissue-specific antigen. In one embodiment, the method of imaging is selected from the group consisting of magnetic resonance imaging, ultrasound imaging; and computer axaial tomography (CAT). In one aspect, the invention provides a device comprising a microchip operatively associated with a biosensor comprising a minicell, wherein the microchip comprises or contacts the minicell, and wherein the minicell displays a binding moiety.[0116]
• In one embodiment, the invention provides a method of detecting a substance that is specifically bound by a binding moiety, comprising contacting the device of claim 16 with a composition known or suspected to contain the substance, and detecting a signal from the device, wherein the signal changes as a function of the amount of the substance present in the composition. In one embodiment, the composition is a biological sample or an environmental sample.[0117]
• In one aspect, the invention provides a method of identifying an agent that specifically binds a target compound, comprising contacting a minicell displaying the target compound with a library of compounds, and identifying an agent in the library that binds the target compound. In one embodiment, the library of compounds is a protein library. In one embodiment, the protein library is selected from the group consisting of a phage display library, a phagemid display library, a baculovirus library, a yeast display library, and a ribosomal display library. In one embodiment, the library of compounds is selected from the group consisting of a library of aptamers, a library of synthetic peptides and a library of small molecules.[0118]
• In one embodiment, the target compound is a target polypeptide. In one embodiment, the minicell comprises an expression construct comprising expression sequences operably linked to an ORF encoding the target polypeptide. In one embodiment, the target polypeptide is a membrane protein. In one embodiment, the membrane protein is a receptor or a channel protein. In one embodiment, the membrane protein is an enzyme. In one embodiment, the target compound is a membrane fusion protein, the membrane fusion protein comprising a first polypeptide, wherein the first polypeptide comprises at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide comprises amino acid sequences derived from a target polypeptide. In one embodiment, the method further comprises comparing the activity of the target compound in the presence of the agent to the activity of the target compound in the absence of the agent.[0119]
• In one embodiment, the activity of the target compound is an enzyme activity. In one embodiment, the activity of the target compound is a binding activity. In one embodiment, the invention further comprises comparing the binding of the agent to the target compound to the binding of a known ligand of the target compound. In one embodiment, a competition assay is used for the comparing.[0120]
• In one aspect, the invention provides a device comprising microchips operatively associated with a biosensor comprising a set of minicells in a prearranged pattern, wherein the each of the microchips comprise or contact a minicell, wherein each of the minicell displays a different target compound, and wherein binding of a ligand to a target compound results in an increased or decreased signal. In one embodiment, the invention provides a method of identifying an agent that specifically binds a target compound, comprising contacting the device with a library of compounds, and detecting a signal from the device, wherein the signal changes as a function of the binding of an agent to the target compound. In one embodiment, the invention provides a method of identifying an agent that specifically blocks the binding of a target compound to its ligand, comprising contacting the device with a library of compounds, and detecting a signal from the device, wherein the signal changes as a function of the binding of an agent to the target compound.[0121]
• In one aspect, the invention provides a method of making a antibody that specifically binds a protein domain, wherein the domain is in its native conformation, wherein the domain is contained within a protein displayed on a minicell, comprising contacting the minicell with a cell, wherein the cell is competent for producing antibodies to an antigen contacted with the cell, in order to generate an immunogenic response in which the cell produces the antibody.[0122]
• In one embodiment, the protein displayed on a minicell is a membrane protein. In one embodiment, the membrane protein is a receptor or a channel protein. In one embodiment, the domain is found within the second polypeptide of a membrane fusion protein, wherein the membrane fusion protein comprises a first polypeptide, wherein the first polypeptide comprises at least one transmembrane domain or at least one membrane anchoring domain. In one embodiment, the contacting occurs in vivo. In one embodiment, the antibody is a polyclonal antibody or a monoclonal antibody. In one embodiment, the contacting occurs in an animal that comprises an adjuvant.[0123]
• In one aspect, the invention provides the method of making an antibody derivative that specifically binds a protein domain, wherein the domain is in its native conformation, wherein the domain is displayed on a minicell, comprising contacting the minicell with a protein library, and identifying an antibody derivative from the protein library that specifically binds the protein domain. In one embodiment, the protein library is selected from the group consisting of a phage display library, a phagemid display library, and a ribosomal display library.[0124]
• In one aspect, the invention provides a method of making an antibody or antibody derivative that specifically binds an epitope, wherein the epitope is selected from the group consisting of (i) an epitope composed of amino acids found within a membrane protein, (ii) an epitope present in an interface between a membrane protein and a membrane component, (iii) an epitope present in an interface between a membrane protein and one or more other proteins and (iv) an epitope in a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain, and a second polypeptide, the second polypeptide comprising the epitope; comprising contacting a minicell displaying the epitope with a protein library, or to a cell, wherein the cell is competent for producing antibodies to an antigen contacted with the cell, in order to generate an immunogenic response in which the cell produces the antibody.[0125]
• In one embodiment, the cell is contacted in vivo. In various embodiments, the antibody is a polyclonal antibody or a monoclonal antibody. In one embodiment, the protein library is contacted in vitro. In one embodiment, the protein library is selected from the group consisting of a phage display library, a phagemid display library, and a ribosomal display library.[0126]
• In one aspect, the invention provides a method of determining the rate of transfer of nucleic acid from a minicell to a cell, comprising (a) contacting the cell to the minicell, wherein the minicell comprises the nucleic acid, for a measured period of time; (b) separating minicells from the cells; (c) measuring the amount of nucleic acid in the cells,wherein the amount of nucleic acid in the cells over the set period of time is the rate of transfer of a nucleic acid from a minicell.[0127]
• In one aspect, the invention provides a method of determining the amount of a nucleic acid transferred to a cell from a minicell, comprising (a) contacting the cell to the minicell, wherein the minicell comprises an expression element having eukaryotic expression sequences operably linked to an ORF encoding a detectable polypeptide, wherein the minicell displays a binding moiety, and wherein the binding moiety binds an epitope of the cell; and (b) detecting a signal from the detectable polypeptide, wherein a change in the signal corresponds to an increase in the amount of a nucleic acid transferred to a cell.[0128]
• In one embodiment, the cell is a eukaryotic cell. By way of non-limiting example, a eukaryotic cell can be a plant cell, a fungal cell, a unicellular eukaryote, an animal cell, a mammalian cell, a rat cell, a mouse cell, a primate cell or a human cell.[0129]
• In one embodiment, the binding moiety is an antibody or antibody derivative. In one embodiment, the binding moiety is a single-chain antibody. In one embodiment, the binding moiety is an aptamer. In one embodiment, the binding moiety is an organic compound. In one embodiment, the detectable polypeptide is a fluorescent polypeptide.[0130]
• In one aspect, the invention provides a method of detecting the expression of an expression element in a cell, comprising (a) contacting the cell to a minicell, wherein the minicell comprises an expression element having cellular expression sequences operably linked to an ORF encoding a detectable polypeptide, wherein the minicell displays a binding moiety, and wherein the binding moiety binds an epitope of the cell; (b) incubating the cell and the minicell for a period of time effective for transfer of nucleic acid from the minicell to the cell; and (c) detecting a signal from the detectable polypeptide, wherein an increase in the signal corresponds to an increase in the expression of the expression element.[0131]
• In one embodiment, the cell is a eukaryotic cell and the expression sequences are eukaryotic expression sequences. In one embodiment, the eukaryotic cell is a mammalian cell. In one embodiment, the binding moiety is an antibody or antibody derivative. In one embodiment, the binding moiety is a single-chain antibody. In one embodiment, the binding moiety is an aptamer. In one embodiment, the binding moiety is an organic compound.[0132]
• In a related aspect, the invention provides methods of detecting the transfer of a fusion protein from the cytosol to an organelle of a eukaryotic cell, comprising (a) contacting the cell to a minicell, wherein (i) the minicell comprises an expression element having eukaryotic expression sequences operably linked to an ORF encoding a fusion protein, wherein the fusion protein comprises a first polypeptide that comprises organellar delivery sequences, and a second polypeptide that comprises a detectable polypeptide; and (ii) the minicell displays a binding moiety that binds an epitope of the cell, or an epitope of an organelle; (b) incubating the cell and the minicell for a period of time effective for transfer of nucleic acid from the minicell to the cell and production of the fusion protein; and (c) detecting a signal from the detectable polypeptide, wherein a change in the signal corresponds to an increase in the amount of the fusion protein transferred to the organelle.[0133]
• In one aspect, the invention provides a minicell comprising at least one nucleic acid, wherein the minicell displays a binding moiety directed to a target compound, wherein the binding moiety is selected from the group consisting of (i) a eukaryotic membrane protein; (ii) an archeabacterial membrane protein; (iii) an organellar membrane protein; and (iv) a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein and is neither a His tag nor a glutathione-S-transferase polypeptide, and wherein the polypeptide comprises a binding moiety.[0134]
• In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF encoding a protein selected from the group consisting of (i) the eukaryotic membrane protein, (ii) the archeabacterial membrane protein, (iii) the organellar membrane protein; and (iv) the fusion protein.[0135]
• In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF, wherein the ORF encodes a therapeutic polypeptide. In one embodiment, the therapeutic polypeptide is a membrane polypeptide. In one embodiment, the therapeutic polypeptide is a soluble polypeptide. In one embodiment, the soluble polypeptide comprises a cellular secretion sequence. In one embodiment, the expression sequences are inducible and/or repressible.[0136]
• In one embodiment, the expression sequences are induced and/or derepressed when the binding moiety displayed by the minicell binds to its target compound. In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF, wherein the ORF encodes a polypeptide having an amino acid sequence that facilitates cellular transfer of a biologically active compound contained within or displayed by the minicell. In one embodiment, the membrane of the minicell comprises a system for transferring a molecule from the interior of a minicell into the cytoplasm of the cell. In one embodiment, the system for transferring a molecule from the interior of a minicell into the cytoplasm of the cell is a Type III secretion system.[0137]
• In one aspect, the invention provides a method of introducing a nucleic acid into a cell, comprising contacting the cell with a minicell that comprises the nucleic acid, wherein the minicell displays a binding moiety, wherein the binding moiety is selected from the group consisting of (i) a eukaryotic membrane protein; (ii) an archeabacterial membrane protein; (iii) an organellar membrane protein; and (iv) a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain; and a second polypeptide, wherein the second polypeptide is not derived from a eubacterial protein and is neither a His tag nor a glutathione-S-transferase polypeptide, and wherein the polypeptide comprises a binding moiety; and wherein the binding moiety binds an epitope of the cell.[0138]
• In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF encoding a protein selected from the group consisting of (i) the eukaryotic membrane protein, (ii) the archeabacterial membrane protein, (iii) the organellar membrane protein; and (iv) a fusion protein.[0139]
• In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF, wherein the ORF encodes a therapeutic polypeptide. In one embodiment, the expression sequences are inducible and/or derepressible. In one embodiment, the expression sequences are induced or derepressed when the binding moiety displayed by the minicell binds its target compound. In one embodiment, the expression sequences are induced or derepressed by a transactivation or transrepression event. In one embodiment, the nucleic acid comprises an expression construct comprising expression sequences operably linked to an ORF, wherein the ORF encodes a polypeptide having an amino acid sequence that facilitates cellular transfer of a biologically active compound contained within or displayed by the minicell.[0140]
• In one aspect, the invention provides a minicell comprising a nucleic acid, wherein the nucleic acid comprises eukaryotic expression sequences and eubacterial expression sequences, each of which is independently operably linked to an ORF.[0141]
• In one embodiment, the minicell displays a binding moiety. In one embodiment, the eubacterial expression sequences are induced and/or derepressed when the binding moiety is in contact with a target cell. In one embodiment, the eukaryotic expression sequences are induced and/or derepressed when the nucleic acid is in the cytoplasm of a eukaryotic cell. In one embodiment, the protein encoded by the ORF comprises eubacterial or eukaryotic secretion sequences.[0142]
• In one aspect, the invention provides a minicell comprising a first and second nucleic acid, wherein the first nucleic acid comprises eukaryotic expression sequences operably linked to a first ORF, and a second nucleic acid, wherein the second nucleic acid comprises eubacterial expression sequences operably linked to a second ORF.[0143]
• In one embodiment, the minicell displays a binding moiety. In one embodiment, the eubacterial expression sequences are induced and/or derepressed when the binding moiety is in contact with a target cell. In one embodiment, the eukaryotic expression sequences are induced and/or derepressed when the nucleic acid is in the cytoplasm of a eukaryotic cell. In one embodiment, the protein encoded by the first ORF comprises eukaryotic secretion sequences and/or the protein encoded by the second ORF comprises eubacterial secretion sequences.[0144]
• In one aspect, the invention provides a method of introducing into and expressing a nucleic acid in an organism, comprising contacting a minicell to a cell of the organism, wherein the minicell comprises the nucleic acid.[0145]
• In one embodiment, the minicell displays a binding moiety. In one embodiment, the nucleic acid comprises a eukaryotic expression construct, wherein the eukaryotic expression construct comprises eukaryotic expression sequences operably linked to an ORF. In one embodiment, the ORF encodes a protein selected from the group consisting of a membrane protein, a soluble protein and a protein comprising eukaryotic secretion signal sequences. In one embodiment, the nucleic acid comprises a eubacterial expression construct, wherein the eubacterial expression construct comprises eubacterial expression sequences operably linked to an ORF. In one embodiment, the minicell displays a binding moiety, wherein the eubacterial expression sequences are induced and/or derepressed when the binding moiety is in contact with a target cell. In one embodiment, the protein encoded by the ORF comprises eubacterial secretion sequences. In one aspect, the invention provides a minicell comprising a crystal of a membrane protein. In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the membrane protein is a receptor. In one embodiment, the receptor is a G-protein coupled receptor. In one embodiment, the crystal is displayed.[0146]
• In a related aspect, the invention provides a minicell membrane preparation comprising a crystal of a membrane protein.[0147]
• In one embodiment, the membrane protein is a fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain, and a second polypeptide. In one embodiment, the crystal is a crystal of the second polypeptide. In one embodiment, the crystal is displayed.[0148]
• In one aspect, the invention provides a method of determining the three-dimensional structure of a membrane protein, comprising preparing a crystal of the membrane protein in a minicell, and determining the three-dimensional structure of the crystal.[0149]
• In one aspect, the invention provides a method for identifying ligand-interacting atoms in a defined three-dimensional structure of a target protein, comprising (a) preparing one or more variant proteins of a target protein having a known or predicted three-dimensional structure, wherein the target protein binds a preselected ligand; (b) expressing and displaying a variant protein in a minicell; and (c) determining if a minicell displaying the variant protein binds the preselected ligand with increased or decreased affinity as compared to the binding of the preselected ligand to the target protein.[0150]
• In one embodiment, the ligand is a protein that forms a multimer with the target protein, and the ligand interacting atoms are atoms in the defined three-dimensional structure are atoms that are involved in protein-protein interactions. In one embodiment, the ligand is a compound that induces a conformational change in the target protein, and the defined three-dimensional structure is the site of the conformational change. In one embodiment, the method for identifying ligands of a target protein, further comprising identifying the chemical differences in the variant proteins as compared to the target protein. In one embodiment, the invention further comprises mapping the chemical differences onto the defined three-dimensional structure, and correlating the effect of the chemical differences on the defined three-dimensional structure. In one embodiment, the target protein is a wild-type protein. In one aspect, the invention provides a minicell library, comprising two or more minicells, wherein each minicell comprises a different exogenous protein. In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the exogenous protein is a displayed protein. In one embodiment, the exogenous protein is a membrane protein. In one embodiment, the membrane protein is a receptor. In one embodiment, the protein is a soluble protein that is contained within or secreted from the minicell. In one embodiment, minicells within the library comprise an expression element that comprises expression sequences operably linked to a nucleic acid having an ORF that encodes the exogenous protein. In one embodiment, the nucleic acid has been mutagenized; the mutagenesis can be site-directed or random. In one embodiment, an active site of the exogenous protein has a known or predicted three-dimensional structure, and the a portion of the ORF encoding the active site has been mutagenized. In one embodiment, each of the minicells comprises an exogenous protein that is a variant of a protein having a known or predicted three-dimensional structure.[0151]
• In one aspect, the invention provides a minicell library, comprising two or more minicells, wherein each minicell comprises a different fusion protein, each of the fusion protein comprising a first polypeptide that is a constant polypeptide, wherein the constant polypeptide comprises at least one transmembrane domain or at least one membrane anchoring domain, and a second polypeptide, wherein the second polypeptide is a variable amino acid sequence that is different in each fusion proteins. In one embodiment, minicells within the library comprise an expression element that comprises expression sequences operably linked to a nucleic acid having an ORF that encodes the fusion protein. In one embodiment, the second polypeptide of the fusion protein is encoded by a nucleic acid that has been cloned. In one embodiment, each of the second polypeptide of each of the fusion proteins comprises a variant of an amino acid sequence from a protein having a known or predicted three-dimensional structure.[0152]
• In one aspect, the invention provides a minicell library, comprising two or more minicells, wherein each minicell comprises a constant protein that is present in each minicell and a variable protein that differs from minicell to minicell. In one embodiment, one of the constant and variable proteins is a receptor, and the other of the constant and variable proteins is a co-receptor. In one embodiment, each of the constant and variable proteins is different from each other and is a factor in a signal transduction pathway. In one embodiment, one of the constant and variable proteins is a G-protein, and the other of the constant and variable proteins is a G-protein coupled receptor.[0153]
• In one embodiment, one of the constant and variable proteins comprises a first transrepression domain, and the other of the constant and variable comprises a second transrepression domain, wherein the transrepression domains limit or block expression of a reporter gene when the constant and variable proteins associate with each other.[0154]
• In one embodiment, one of the constant and variable proteins comprises a first transactivation domain, and the other of the constant and variable comprises a second transactivation domain, wherein the transactivation domains stimulate expression of a reporter gene when the constant and variable proteins associate with each other.[0155]
• In one aspect, the invention provides a method of identifying a nucleic acid that encodes a protein that binds to or chemically alters a preselected ligand, comprising (a) separately contacting the ligand with individual members of a minicell library, wherein minicells in the library comprise expression elements, wherein the expression elements comprise DNA inserts, wherein an ORF in the DNA insert is operably linked to expression sequences, in order to generate a series of reaction mixes, each reaction mix comprising a different member of the minicell library; (b) incubating the reaction mixes, thereby allowing a protein that binds to or chemically alters the preselected ligand to bind or chemically alter the preselected ligand; (c) detecting a change in a signal from reaction mixes in which the ligand has been bound or chemically altered; (d) preparing DNA from reaction mixes in which the ligand has been bound or chemically altered; wherein the DNA is a nucleic acid that encodes a protein that binds to or chemically alters the preselected ligand.[0156]
• In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the preselected ligand is a biologically active compound. In one embodiment, the preselected ligand is a therapeutic drug. In one embodiment, a protein that binds or chemically alters the preselected ligand is a target protein for compounds that are therapeutic for a disease that is treated by administering the drug to an organism in need thereof. In one embodiment, the preselected ligand is detectably labeled, the mincell comprises a detectable compound, and/or a chemically altered derivative of the protein is detectably labeled.[0157]
• In one aspect, the invention provides a method of determining the amino acid sequence of a protein that binds or chemically alters a preselected ligand, comprising: (a) contacting the ligand with a minicell library, wherein minicells in the library comprise expression elements, wherein the expression elements comprise DNA inserts, wherein an ORF in the DNA insert is operably linked to expression sequences; (b) incubating the mixture of ligand and minicells, under conditions which allow complexes comprising ligands and minicells to form and/or chemical reactions to occur; (c) isolating or identifying the complexes from the ligand and the mixture of ligand and minicells; (d) preparing DNA from an expression element found in one or more of the complexes, or in a minicell thereof; (e) determining the nucleotide sequence of the ORF in the DNA; and (f) generating an amino sequence by in silico translation, wherein the amino acid sequence is or is derived from a protein that binds or chemically alters a preselected ligand.[0158]
• In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the DNA is prepared by isolating DNA from the complexes, or in a minicell thereof. In one embodiment, the DNA is prepared by amplifying DNA from the complexes, or in a minicell thereof. In one embodiment, the protein is a fusion protein. In one embodiment, the protein is a membrane or a soluble protein. In one embodiment, the protein comprises secretion sequences. In one embodiment, the preselected ligand is a biologically active compound. In one embodiment, the preselected ligand is a therapeutic drug. In one embodiment, the preselected ligand is a therapeutic drug, and the protein that binds the preselected ligand is a target protein for compounds that are therapeutic for a disease that is treated by administering the drug to an organism in need thereof.[0159]
• In one aspect, the invention provides a method of identifying a nucleic acid that encodes a protein that inhibits or blocks an agent from binding to or chemically altering a preselected ligand, comprising: (a) separately contacting the ligand with individual members of a minicell library, wherein minicells in the library comprise expression elements, wherein the expression elements comprise DNA inserts, wherein an ORF in the DNA insert is operably linked to expression sequences, in order to generate a series of reaction mixes, each reaction mix comprising a different member of the minicell library; (b) incubating the reaction mixes, thereby allowing a protein that binds to or chemically alters the preselected ligand to bind or chemically alter the preselected ligand; (c) detecting a change in a signal from reaction mixes in which the ligand has been bound or chemically altered; (d) preparing DNA from reaction mixes in which the change in signal ligand has been bound or chemically altered; wherein the DNA is a nucleic acid that encodes a protein that inhibits or blocks the agent from binding to or chemically altering the preselected ligand[0160]
• In one embodiment, the minicell is a eubacterial minicell, a poroplast, a spheroplast or a protoplast. In one embodiment, the DNA has a nucleotide sequence that encodes the amino acid sequence of the protein that inhibits or blocks the agent from binding to or chemically altering the preselected ligand. In one embodiment, a protein that binds or chemically alters the preselected ligand is a target protein for compounds that are therapeutic for a disease that is treated by administering the drug to an organism in need thereof.[0161]
• In one aspect, the invention provides a method of identifying an agent that effects the activity of a protein, comprising contacting a library of two or more candidate agents with a minicell comprising the protein or a polypeptide derived from the protein, assaying the effect of candidate agents on the activity of the protein, and identifying agents that effect the activity of the protein.[0162]
• In one embodiment, the protein or the polypeptide derived from the protein is displayed on the surface of the minicell. In one embodiment, the protein is a membrane protein. In one embodiment, the membrane protein is selected from the group consisting of a receptor, a channel protein and an enzyme. In one embodiment, the activity of a protein is a binding activity or an enzymatic activity. In one embodiment, the library of compounds is a protein library. In one embodiment, the protein library is selected from the group consisting of a phage display library, a phagemid display library, and a ribosomal display library. In one embodiment, the library of compounds is a library of aptamers. In one embodiment, the library of compounds is a library of small molecules.[0163]
• In one aspect, the invention provides a method of identifying an agent that effects the activity of a protein domain containing a library of two or more candidate agents with a minicell displaying a membrane fusion protein, the fusion protein comprising a first polypeptide, the first polypeptide comprising at least one transmembrane domain or at least one membrane anchoring domain, and a second polypeptide, wherein the second polypeptide comprises the protein domain.[0164]
• In one aspect, the invention provides a method of identifying undesirable side-effects of a biologically active compound that occur as a result of binding of the compound to a protein, wherein binding a compound to the protein is known to result in undesirable side effects, comprising contacting a minicell that comprises the protein to the biologically active compound. In one embodiment, the invention provides comprises characterizing the binding of the biologically active compound to the protein. In one embodiment, the invention provides comprises characterizing the effect of the biologically active compound on the activity of the protein.[0165]
• In one aspect, the invention provides a method for identifying an agent that effects the interaction of a first signaling protein with a second signaling protein, comprising (a) contacting a library of compounds with a minicell, wherein the minicell comprises: (i) a first protein comprising the first signaling protein and a first trans-acting regulatory domain; (ii) a second protein comprising the second signaling protein and a second trans-acting regulatory domain; and (iii) a reporter gene, the expression of which is modulated by the interaction between the first trans-acting regulatory domain and the second trans-acting regulatory domain; and (b) detecting the gene product of the reporter gene.[0166]
• In one embodiment, the trans-acting regulatory domains are transactivation domains. In one embodiment, the trans-acting regulatory domains are transrepression domains.[0167]
• In one embodiment, the reporter gene is induced by the interaction of the first trans-acting regulatory domain and the second trans-acting regulatory domain. In one embodiment, the agent that effects the interaction of the first signaling protein with the second signaling protein is an agent that causes or promotes the interaction. In one embodiment, the reporter gene is repressed by the interaction of the first trans-acting regulatory domain and the second trans-acting regulatory domain. In one embodiment, the agent that effects the interaction of the first signaling protein with the second signaling protein is an agent that inhibits or blocks the interaction.[0168]
• In one embodiment, the first signaling protein is a GPCR. In one embodiment, the GPCR is an Edg receptor or a ScAMPER.[0169]
• In one embodiment, the second signalling protein is a G-protein. In related embodiments, G-protein is selected from the group consisting of G-alpha-i, G-alpha-s, G-alpha-q, G-alpha-12/13 and Go. In one embodiment, the library of compounds is a protein library. In one embodiment, the protein library is selected from the group consisting of a phage display library, a phagemid display library, and a ribosomal display library. In one embodiment, the library of compounds is a library of aptamers. In one embodiment, the library of compounds is a library of small molecules.[0170]
• In one aspect, the invention provides a method for identifying an agent that effects the interaction of a first signaling protein with a second signaling protein, comprising contacting a library of two or more candidate agents with a minicell, wherein the minicell comprises (a) a first fusion protein comprising the first signaling protein and a first detectable domain; and (b) a second fusion protein comprising the second signaling protein and a second detectable domain, wherein a signal is generated when the first and second signaling proteins are in close proximity to each other, and detecting the signal.[0171]
• In one embodiment, the signal is fluorescence. In one embodiment, the first detectable domain and the second detectable domain are fluorescent and the signal is generated by FRET. In one embodiment, the first and second detectable domains are independently selected from the group consisting of a green fluorescent protein, a blue-shifted green fluorescent protein, a cyan-shifted green fluorescent protein; a red-shifted green fluorescent protein; a yellow-shifted green fluorescent protein, and a red fluorescent protein, wherein the first fluorescent domain and the second fluorescent domain are not identical.[0172]
• In one aspect, the invention provides a method of bioremediation, the method comprising contacting a composition that comprises an undesirable substance with a minicell, wherein the minicell alters the chemical structure and/or binds the undesirable substance.[0173]
• In one aspect, the invention provides a method of bioremediation, the method comprising contacting a composition that comprises an undesirable substance with a minicell, wherein the mincell comprises an agent that alters the chemical structure of the undesirable substance. In one embodiment, the agent that alters the chemical structure of the undesirable substance is an inorganic catalyst. In one embodiment, the agent that alters the chemical structure of the undesirable substance is an enzyme. In one embodiment, the enzyme is a soluble protein contained within the minicell. In one embodiment, the enzyme is a secreted protein. In one embodiment, the enzyme is a membrane protein. In one embodiment, the membrane enzyme is selected from the group consisting of a cytochrome P450, an oxidoreductase, a transferase, a hydrolase, a lyase, an isomerase, a ligase and a synthetase. In one embodiment, the agent that alters the chemical structure of the undesirable substance is a fusion protein comprising a first polypeptide that comprises a transmembrane domain or at least one membrane-anchoring domain, and a second polypeptide, wherein the second polypeptide is an enzyme moiety.[0174]
• In one aspect, the invention provides a method of bioremediation, the method comprising contacting a composition that comprises an undesirable substance with a minicell, wherein the mincell comprises an agent that binds an undesirable substance. In one embodiment, the undesirable substance binds to and is internalized by the minicell or is otherwise inactivated by selective absorption. In one embodiment, the agent that binds the undesirable substance is a secreted soluble protein. In one embodiment, the secreted protein is a transport accessory protein. In one embodiment, the agent that binds the undesirable substance is a membrane protein. In one embodiment, the undesirable substance is selected from the group consisting of a toxin, a pollutant and a pathogen. In one embodiment, the agent that binds the undesirable substance is a fusion protein comprising a first polypeptide that comprises a transmembrane domain or at least one membrane-anchoring domain, and a second polypeptide, wherein the second polypeptide is a binding moiety. In one embodiment, wherein the binding moiety is selected from the group consisting of an antibody, an antibody derivative, the active site of a non-enzymatically active mutant enzyme, a single-chain antibody and an aptamer.[0175]
• In one aspect, the invention provides a minicell-producing parent cell, wherein the parent cell comprises one or more of the following (a) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of the gene regulates the copy number of an episomal expression construct; (b) a mutation in an endogenous gene, wherein the mutation regulates the copy number of an episomal expression construct; (c) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of the gene causes or enhances the production of minicells; and (d) a mutation in an endogenous gene, wherein the mutation causes or enhances minicell production.[0176]
• In one embodiment, the invention comprises an episomal expression construct. In one embodiment, the invention further comprises a chromosomal expression construct. In one embodiment, the expression sequences of the expression construct are inducible and/or repressible. In one embodiment, the minicell-producing parent cell comprises a biologically active compound. In one embodiment, the gene that causes or enhances the production of minicells has a gene product that is involved in or regulates DNA replication, cellular division, cellular partitioning, septation, transcription, translation, or protein folding.[0177]
• In one aspect, the invention provides a minicell-producing parent cell, wherein the parent cell comprises an expression construct, wherein the expression construct comprises expression sequences operably linked to an ORF that encodes a protein, and a regulatory expression element, wherein the regulatory expression element comprises expression sequences operably linked to a regulatory gene that encodes a factor that regulates the expression of the ORF. In one embodiment, the expression sequences of the expression construct are inducible and/or repressible. In one embodiment, the expression sequences of the regulatory expression construct are inducible and/or repressible. In one embodiment, one or more of the expression element or the regulatory expression element is located on a chromosome of the parent cell. In one embodiment, one or more of the expression element or the regulatory expression element is located on an episomal expression construct. In one embodiment, both of the expression element and the regulatory expression element are located on an episomal expression construct, and one or both of the expression element and the regulatory expression element segregates into minicells produced from the parent cell. In one embodiment, the minicell-producing parent cell comprises a biologically active compound. In one embodiment, the biologically active compound segregates into minicells produced from the parent cell. In one embodiment, the ORF encodes a membrane protein or a soluble protein. In one embodiment, the protein comprises secretion sequences. In one embodiment, the gene product of the gene regulates the expression of the ORF. In one embodiment, the gene product is a transcription factor. In one embodiment, the gene product is a RNA polymerase. In one embodiment, the parent cell is MC-T7.[0178]
• In one aspect, the invention provides a minicell comprising a biologically active compound, wherein the minicell displays a binding moiety, wherein the minicell selectively absorbs and/or internalizes an undesirable compound, and the minicell is a poroplast, spheroplast or protoplast. In one embodiment, the binding moiety is selected from the group consisting of an antibody, an antibody derivative, a receptor and an active site of a non-catalytic derivative of an enzyme. In one embodiment, the binding moiety is a single-chain antibody. In one embodiment, the binding moiety is directed to a ligand selected from the group consisting of an epitope displayed on a pathogen, an epitope displayed on an infected cell and an epitope displayed on a hyperproliferative cell. In one embodiment, the biologically active compound is selected from the group consisting of a radioisotope, a polypeptide, a nucleic acid and a small molecule. In one embodiment, a ligand binds to and is internalized by the minicell or is otherwise inactivated by selective absorption. In one embodiment, the invention provides a pharmaceutical composition comprising the minicell. In one aspect, the invention provides a method of reducing the free concentration of a substance in a composition, wherein the substance displays a ligand specifically recognized by a binding moiety, comprising contacting the composition with a minicell that displays the binding moiety, wherein the binding moiety binds the substance, thereby reducing the free concentration of the substance in the composition. In one embodiment, the substance is selected from the group consisting of a nucleic acid, a lipid, a polypeptide, a radioactive compound, an ion and a small molecule. In one embodiment, the binding moiety is selected from the group consisting of an antibody, an antibody derivative, a channel protein and a receptor.[0179]
• In one embodiment, the composition is present in an environment including but not limited to water, air or soil. In one embodiment, the composition is a biological sample from an organism, including but not limited to blood, serum, plasma, urine, saliva, a biopsy sample, feces, tissue and a skin patch. In one embodiment, the substance binds to and is internalized by the minicell or is otherwise inactivated by selective absorption. In one embodiment, the biological sample is returned to the organism after being contacting to the minicell.[0180]
• For a better understanding of the present invention, reference is made to the accompanying detailed description and its scope will be pointed out in the appended claims. All references cited herein are hereby incorporated by reference.[0181]
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a Western blot in which Edg-1-6×His and Edg-3-6×His proteins expressed in minicells produced from MC-T7 cells.[0182]
• FIG. 2 shows induction of MalE(L)-NTR in isolated minicells.[0183]
• Abbreviations and Definitions[0184]
• For brevity's sake, the single-letter amino acid abbreviations are used in some instances herein. Table 1 describes the correspondence between the 1- and 3-letter amino acid abbreviations.[0185]

  TABLE 1
  THREE- AND ONE-LETTER ABBREVIATIONS
  FOR AMINO ACIDS

  		Three-letter	One-letter
  	Amino acid	abbreviation	symbol
  	Alanine	Ala	A
  	Arginine	Arg	R
  	Asparagine	Asn	N
  	Aspartic Acid	Asp	D
  	Cysteine	Cys	C
  	Glutamine	Gln	Q
  	Glutamic acid	Glu	E
  	Glycine	Gly	G
  	Histidine	His	H
  	Isoleucine	Ile	I
  	Leucine	Leu	L
  	Lysine	Lys	K
  	Methionine	Met	M
  	Phenylalanine	Phe	F
  	Proline	Pro	P
  	Serine	Ser	S
  	Threonine	Thr	T
  	Tryptophan	Trp	W
  	Tyrosine	Tyr	Y
  	Valine	Val	V

• A “conjugatable compound” or “attachable compound” is capable of being attached to another compound. The terms “conjugated to” and “cross-linked with” indicate that the conjugatable compound is in the state of being attached to another compound.A “conjugate” is the compound formed by the attachment of a conjugatable compound or conjugatable moiety to another compound. “Culturing” signifies incubating a cell or organism under conditions wherein the cell or organism can carry out some, if not all, biological processes. For example, a cell that is cultured may be growing or reproducing, or it may be non-viable but still capable of carrying out biological and/or biochemical processes such as replication, transcription, translation, etc.[0186]
• An agent is said to have been “purified” if its concentration is increased, and/or the concentration of one or more undesirable contaminants is decreased, in a composition relative to the composition from which the agent has been purified. Purification thus encompasses enrichment of an agent in a composition and/or isolation of an agent therefrom.[0187]
• A “solid support” is any solid or semisolid composition to which an agent can be attached or contained within. Common forms of solid support include, but are not limited to, plates, tubes, and beads, all of which could be made of glass or another suitable material, e.g., polystyrene, nylon, cellulose acetate, nitrocellulose, and other polymers. Semisolids and gels that minicells are suspended within are also considered to be solid supports. A solid support can be in the form of a dipstick, flow-through device, or other suitable configuration.[0188]
• A “mutation” is a change in the nucleotide sequence of a gene relative to the sequence of the “wild-type” gene. Reference wild-type eubacterial strains are those that have been cultured in vitro by scientists for decades; for example, a wild-type strain of[0189]Escherichia coliissE. coliK-12. Mutations include, but are not limited to, point mutations, deletions, insertions and translocations.
• A “trans-acting regulatory domain” is a regulatory part of a protein that is expressed from a gene that is not adjacent to the site of regulatory effect. Trans-acting domains can activate or stimulate (transactivate), or limit or block (transrepress) the gene in question.[0190]
• A “reporter gene” refers to a gene that is operably linked to expression sequences, and which expresses a gene product, typically a detectable polypeptide, the production and detection of which is used as a measure of the robustness and/or control of expression.[0191]
• A “detectable compound” or “detectable moiety” produces a signal that can be detected by spectroscopic, photochemical, biochemical, immunochemical, electromagnetic, radiochemical, or chemical means such as fluorescence, chemifluoresence, or chemiluminescence, or any other appropriate means. A “radioactive compound” or “radioactive composition” has more than the natural (environmental) amount of one or more radioisotopes.[0192]
• By “displayed” it is meant that a portion of the membrane protein is present on the surface of a cell or minicell, and is thus in contact with the external environment of the cell or minicell. The external, displayed portion of a membrane protein is an “extracellular domain” or a “displayed domain.” A membrane protein may have more than one displayed domain, and a minicell of the invention may display more than one membrane protein.[0193]
• A “domain” or “protein domain” is a region of a molecule or structure that shares common physical and/or chemical features. Non-limiting examples of protein domains include hydrophobic transmembrane or peripheral membrane binding regions, globular enzymatic or receptor regions, and/or nucleic acid binding domains.[0194]
• A “transmembrane domain” spans a membrane, a “membrane anchoring domain” is positioned within, but does not traverse, a membrane. An “extracellular” or “displayed” domain is present on the exterior of a cell, or minicell, and is thus in contact with the external environment of the cell or minicell.[0195]
• A “eukaryote” is as the term is used in the art. A eukaryote may, by way of non-limiting example, be a fungus, a unicellular eukaryote, a plant or an animal. An animal may be a mammal, such as a rat, a mouse, a rabbit, a dog, a cat, a horse, a cow, a pig, a simian or a human.[0196]
• A “eukaryotic membrane” is a membrane found in a eukaryote. A eukaryotic membrane may, by way of non-limiting example, a cytoplasmic membrane, a nuclear membrane, a nucleolar membrane, a membrane of the endoplasmic reticulum (ER), a membrane of a Golgi body, a membrane of a lysosome a membrane of a peroxisome, a caveolar membrane, or an inner or outer membrane of a mitochondrion, chloroplast or plastid.[0197]
• The term “endogenous” refers to something that is normally found in a cell as that cell exists in nature.[0198]
• The term “exogenous” refers to something that is not normally found in a cell as that cell exists in nature.[0199]
• A “gene” comprises (a) nucleotide sequences that either (i) act as a template for a nucleic acid gene product, or (ii) that encode one or more open reading frames (ORFs); and (b) expression sequences operably linked to (1) or (2). When a gene comprises an ORF, it is a “structural gene.”[0200]
• By “immunogenic,” it is meant that a compound elicits production of antibodies or antibody derivatives and, additionally or alternatively, a T-cell mediated response, directed to the compound or a portion thereof. The compound is an “immunogen.”[0201]
• A “ligand” is a compound, composition or moiety that is capable of specifically bound by a binding moiety, including without limitation; a receptor and an antibody or antibody derivative.[0202]
• A “membrane protein” is a protein found in whole or in part in a membrane. Typically, a membrane protein has (1) at least one membrane anchoring domain, (2) at least one transmembrane domain, or (3) at least one domain that interacts with a protein having (1) or (2).[0203]
• An “ORF” or “open reading frame” is a nucleotide sequence that encodes an amino acid sequence of a known, predicted or hypothetical polypeptide. An ORF is bounded on its 5′ end by a start codon (usually ATG) and on its 3′ end by a stop codon (i.e., TAA or TGA). An ORF encoding a 10 amino acid sequence comprises 33 nucleotides (3 for each of 10 amino acids and 3 for a stop codon). ORFs can encode amino acid sequences that comprise from 10, 25, 50, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900 or more amino acids[0204]
• The terms “Eubacteria” and“prokaryote” are used herein as these terms are used by those in the art. The terms “eubacterial” and “prokaryotic” encompasses Eubacteria, including both gram-negative and gram-positive bacteria, prokaryotic viruses (e.g., bacteriophage), and obligate intracellular parasites (e.g., Rickettsia, Chlamydia, etc.).[0205]
• An “active site” is any portion or region of a molecule required for, or that regulates, an activity of the molecule. In the case of a protein, an active site can be a binding site for a ligand or a substrate, an active site of enzyme, a site that directs or undergoes conformational change in response to a signal, or a site of post-translational modification of a protein.[0206]
• In a poroplast, the eubacterial outer membrane (OM) and LPS have been removed. In a spheroplast, portions of a disrupted eubacterial OM and/or disrupted cell wall either may remain associated with the inner membrane of the minicell, but the membrane is nonetheless porous because the permeability of the disrupted OM has been increased. A membrane is the to be “disrupted” when the membrane's structure has been treated with an agent, or incubated under conditions, that leads to the partial degradation of the membrane, thereby increasing the permeability thereof. In contrast, a membrane that has been “degraded” is essentially, for the applicable intents and purposes, removed. In preferred embodiments, irrespective of the condition of the OM and cell wall, the eubacterial inner membrane is not disrupted, and membrane proteins displayed on the inner membrane are accessible to compounds that are brought into contact with the minicell, poroplast, spheroplast, protoplast or cellular poroplast, as the case may be.[0207]
• Host cells (and/or minicells) harboring an expression construct are components of expression systems.[0208]
• An “expression vector” is an artificial nucleic acid molecule into which an exogenous ORF encoding a protein, or a template of a bioactive nucleic acid can be inserted in such a manner so as to be operably linked to appropriate expression sequences that direct the expression of the exogenous gene. Preferred expression vectors are episomal vectors that can replicate independently of chromosomal replication.[0209]
• By the term “operably linked” it is meant that the gene products encoded by the non-vector nucleic acid sequences are produced from an expression element in vivo.[0210]
• The term “gene product” refers to either a nucleic acid (the product of transcription, reverse transcription, or replication) or a polypeptide (the product of translation) that is produced using the non-vector nucleic acid sequences as a template.[0211]
• An “expression construct” is an expression vector into which a nucleotide sequence of interest has been inserted in a manner so as to be positioned to be operably linked to the expression sequences present in the expression vector. Preferred expression constructs are episomal.[0212]
• An “expression element” is a nucleic acid having nucleotide sequences that are present in an expression construct but not its cognate expression vector. That is, an expression element for a polypeptide is a nucleic acid that comprises an ORF operably linked to appropriate expression sequences. An expression element can be removed from its expression construct and placed in other expression vectors or into chromosomal DNA.[0213]
• “Expression sequences” are nucleic acid sequences that bind factors necessary for the expression of genes that have been inserted into an expression vector. An example of an expression sequence is a promoter, a sequence that binds RNA polymerase, which is the enzyme that produces RNA molecules using DNA as a template. An example of an expression sequence that is both inducible and repressible is L-arabinose operon (araC). See Schleif R. Regulation of the L-arabinose operon of[0214]Escherichia coli.Trends Genet. December 2000;16(12):559-65.
• In the present disclosure, “a nucleic acid” or “the nucleic acid” refers to a specific nucleic acid molecule. In contrast, the term “nucleic acid” refers to any collection of diverse nucleic acid molecules, and thus signifies that any number of different types of nucleic acids are present. By way of non-limiting example, a nucleic acid may be a DNA, a dsRNA, a tRNA (including a rare codon usage tRNA), an mRNA, a ribosomal RNA (rRNA), a peptide nucleic acid (PNA), a DNA:RNA hybrid, an antisense oligonucleotide, a ribozyme, or an aptamer.[0215]
DETAILED DESCRIPTION OF THE INVENTION
• The invention described herein is drawn to compositions and methods for the production of achromosomal archeabacterial, eubacterial and a nucleate eukaryotic cells that are used for diagnostic and therapeutic applications, for drug discovery, and as research tools.[0216]
• The general advantage of minicells over cell-based expression systems (e.g., eucaryotic cells or bacterial expression systems) is that one may express heterologous membrane bound proteins or over express endogenous membrane bound proteins, cytoplasmic or secreted soluble proteins, or small molecules on the cytoplasmic or extracellular surfaces of the minicells that would otherwise be toxic to live cells. Minicells are also advantageous for proteins that require a particular lipid environment for proper functioning because it is very manipulatable in nature. Other advantages include the stability of the minicells due to the lack of toxicity, the high level of expression that can be achieved in the minicell, and the efficient flexible nature of the minicell expression system. Such minicells could be used for in vivo targeting or for selective absorption (i.e., molecular “sponges”) and that these molecules can be expressed and “displayed” at high levels. Minicells can also be used to display proteins for low, medium, high, and ultra high throughput screening, crystal formation for structure determination, and for in vitro research use only applications such as transfection. Minicells expressing proteins or small molecules, radioisotopes, image-enhancing reagents can be used for in vivo diagnostics and for in vitro diagnostic and assay platforms. Also, soluble and/or membrane associated signaling cascade elements may be reconstituted in minicells producing encapsulated divices to follow extracellular stimulation events using cytoplasmic reporter events, e.g. transactivation resulting from dimerization of dimerization dependant transcriptional activation or repression of said reporter.[0217]
• Regarding protein expression, minicells can be engineered to express one or more recombinant proteins in order to produce more protein per surface area of the particle (at least 10× more protein per unit surface area of protein). The proteins or small molecules that are “displayed” on the minicell surfaces can have therapeutic, discovery or diagnostic benefit either when injected into a patient or used in a selective absorption mode during dialysis. In vitro assays include drug screening and discovery, structural proteomics, and other functional proteomics applications. Proteins that are normally soluble can be tethered to membrane anchoring domains or membrane proteins can be expressed for the purpose of displaying these proteins on the surfaces of the minicell particle in therapeutic, discovery, and diagnostic modes. The types of proteins that can be displayed include but are not limited to receptors (e.g., GPCRs, sphingolipid receptors, neurotransmitter receptors, sensory receptors, growth factor receptors, hormone receptors, chemokine receptors, cytokine receptors, immunological receptors, and complement receptors, FC receptors), channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases.), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN), chemotactic/adhesion proteins (e.g., ICAM11, selectins, CD34, VCAM-1, LFA-1,VLA-1), and chimeric/fussion proteins (e.g., proteins in which a normally soluble protein is attached to a transmembrane region of another protein). As a non-limiting example, the small molecules that can be tethered and displayed on the surfaces of the minicells can be carbohydrates (e.g., monosaccharides), bioactive lipids (e.g., lysosphingolipids, PAF, lysophospholipids), drugs (e.g., antibiotics, ion channel activators/inhibitors, ligands for receptors and/or enzymes), nucleic acids (e.g., synthetic oligonucleotides), fluorophores, metals, or inorganic and organic small molecules typically found in combinatorial chemistry libraries. Minicells may either contain (encapsulate) or display on their surfaces radionuclides or image-enhancing reagents both of which could be used for therapeutic and/or diagnostic benefit in vivo or for in vitro assays and diagnostic platforms.[0218]
• For in vivo therapeutic uses, minicells can express proteins and/or display small molecules on their surfaces that would either promote an immune response and passage through the RES system (e.g., to eliminate the minicell and its target quickly), or to evade the RES (e.g., to increase the bioavailability of the minicell). Toxicity is reduced or eliminated because the therapeutic agent is not excreted or processed by the liver and thus does not damage the kidneys or liver, because the minicell-based therapeutic is not activated until entry into the target cell (e.g., in the case of cancer therapeutics or gene therapy). Minicells are of the appropriate size (from about 0.005, 0.1, 0.15 or 0.2 micrometers to about 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5 micrometers) to facilitate deep penetration into the lungs in the cases where administration of the minicell-based therapeutic or diagnostic is via an inhalant (Strong, A. A., et al. 1987. An aerosol generator system for inhalation delivery of pharmacological agents. Med. Instrum. 21:189-194). This is due to the fact that minicells can be aerosolized. Without being limited to the following examples, inhalant therapeutic uses of minicells could be applied to the treatment of anaphylactic shock, viral infection, inflammatory reactions, gene therapy for cystic fibrosis, treatment of lung cancers, and fetal distress syndrome.[0219]
• Minicells can also display expressed proteins that are enzymes that may have therapeutic and/or diagnostic uses. The enzymes that are displayed may be soluble enzymes that are expressed as fusion proteins with a transmembrane domain of another protein. Display of such enzymes could be used for in vitro assays or for therapeutic benefit.[0220]
• Gene therapy applications afforded by minicells generally involve the ability of minicells to deliver DNA to target cells (either for replacement therapy, modifation of cell function or to kill cells). Expression plasmids can be delivered to target cells that would encode proteins that could be cytoplasmic or could have intracellular signal sequences that would target the protein to a particular organelle (e.g., mitochondria, nuclei, endoplasmic reticulum, etc.). In the case where minicells are engulfed by the taget cell, the minicells themselves could have these intracellular targeting sequences expressed on their surfaces so that the minicells could be ‘delivered’ to intracellular targets.[0221]
• Minicells used for the following therapeutic, discovery, and diagnostic applications can be prepared as described in this application and then stored and/or packaged by a variety of ways, including but not limited to lyophilization, freezing, mixing with preservatives (e.g., antioxidants, glycerol), or otherwise stored and packaged in a fashion similar to methods used for liposome and proteoliposome formulations.[0222]
• The small size of minicells (from about 0.005, 0.1, 0.15 or 0.2 micrometers to about 0.25, 0.3, 0.35, 0.4, 0.45 or 0.5 micrometers) makes them suitable for many in vitro diagnostic platforms, including the non-limiting examples of lateral flow, ELISA, HTS, especially those applications requiring microspheres or nanospheres that display many target proteins or other molecules. The use of protoplast or poroplast minicells may be especially useful in this regard. Assay techniques are dependent on cell or particle size, protein (or molecule to be tested) amount displayed on the surface of the cell or particle, and the sensitivity of the assay being measured. In current whole-cell systems, the expression of the protein of interest is limiting, resulting in the higher cell number requirement to satisfy the sensitivity of most assays. However, the relatively large size of cells prevents the incorporation of large numbers of cells in these assays, e.g. 96, 384, and smaller well formats. In contrast, minicells, protoplasts, and poroplasts are smaller in size and can be manipulated to express high levels of the preselected protein, and can be incorporated into small well assay formats.[0223]
• I. Types of Minicells[0224]
• Minicells are derivatives of cells that lack chromosomal DNA and which are sometimes referred to as anucleate cells. Because eubacterial and achreabacterial cells, unlike eukaryotic cells, do not have a nucleus (a distinct organelle that contains chromosomes), these non-eukaryotic minicells are more accurately described as being “without chromosomes” or “achromosomal,” as opposed to “anucleate.” Nonetheless, those skilled in the art often use the term “anucleate” when referring to bacterial minicells in addition to other minicells. Accordingly, in the present disclosure, the term “minicells” encompasses derivatives of eubacterial cells that lack a chromosome; derivatives of archeabacterial cells that lack their chromosome(s) (Laurence et al., Nucleoid Structure and Partition in Methanococcus jannaschii: An Archaeon With Multiple Copies of the Chromosome, Genetics 152:1315-1323, 1999); and anucleate derivatives of eukaryotic cells. It is understood, however, that some of the relevant art may use the terms “anucleate minicells” or anucleate cells” loosely to refer to any of the preceeding types of minicells.[0225]
• I.A. Eubacterial Minicells[0226]
• One type of minicell is a eubacterial minicell. For reviews of eubacterial cell cycle and division processes, see Rothfield et al., Bacterial Cell Division, Annu. Rev. Genet., 33:423-48, 1999; Jacobs et al., Bacterial cell division: A moveable feast, Proc. Natl. Acad. Sci. USA, 96:5891-5893, May, 1999; Koch, The Bacterium's Way for Safe Enlargement and Division, Appl. and Envir. Microb., Vol. 66, No. 9, pp. 3657-3663; Bouche and Pichoff, On the birth and fate of bacterial division sites. Mol Microbiol, 1998. 29: 19-26; Khachatourians et al., Cell growth and division in[0227]Escherichia coli:a common genetic control involved in cell division and minicell formation. J Bacteriol, 1973. 116: 226-229; Cooper, TheEscherichia colicell cycle. Res Microbiol, 1990. 141: 17-29; and Danachie and Robinson, “Cell Division: Parameter Values and the Process,” in:Escherichia Coli and Salmonella Typhimurium: Cellular and Molecular Biology,Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987, Volume 2, pages 1578-1592, and references cited therein; and Lutkenhaus et al., “Cell Division,” Chapter 101 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^ndEd., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1615-1626, and references cited therein. When DNA replication and/or chromosomal partitioning is altered, membrane-bounded vesicles “pinch off” from parent cells before transfer of chromosomal DNA is completed. As a result of this type of dysfunctional division, minicells are produced which contain an intact outer membrane, inner membrane, cell wall, and all of the cytoplasm components but do not contain chromosomal DNA. See Table 2.
• I.B. Eukaryotic Minicells[0228]
• The term “eukaryote” is defined as is used in the art, and includes any organism classified as Eucarya that are usually classified into four kingdoms: plants, animals, fungi and protists. The first three of these correspond to phylogenetically coherent groups. However, the eucaryotic protists do not form a group, but rather are comprised of many phylogenetically disparate groups (including slime molds, multiple groups of algae, and many distinct groups of protozoa). See, e.g., Olsen, G., http://www.bact.wisc.edu/microtextbook/. A type of animal of particular interest is a mammal, including, by way of non-limiting example a rat, a mouse, a rabbit, a dog, a cat, a horse, a cow, a pig, a simian and a human.[0229]
• Chromosomeless eukaryotic minicells (i.e., anucleate cells) are within the scope of the invention. Platelets are a non-limiting example of eukaryotic minicells. Platelets are anucleate cells with little or no capacity for de novo protein synthesis. The tight regulation of protein synthesis in platelets (Smith et al., Platelets and stroke, Vasc Med 4:165-72, 1999) may allow for the over-production of exogenous proteins and, at the same time, under-production of endogenous proteins. Thrombin-activated expression elements such as those that are associated with Bcl-3 (Weyrich et al., Signal-dependent translation of a regulatory protein, Bcl-3, in activated human platelets, Cel Biology 95:5556-5561, 1998) may be used to modulate the expresion of exogneous genes in platelets.[0230]
• As another non-limiting example, eukaryotic minicells are generated from tumor cell lines (Gyongyossy-Issa and Khachatourians, Tumour minicells: single, large vesicles released from cultured mastocytoma cells (1985) Tissue Cell 17:801-809; Melton, Cell fusion-induced mouse neuroblastomas HPRT revertants with variant enzyme and elevated HPRT protein levels (1981) Somatic Cell Genet 7: 331-344).[0231]
• Yeast cells are used to generate fungal minicells. See, e.g., Lee et al., Ibd1p, a possible spindle pole body associated protein, regulates nuclear division and bud separation in[0232]Saccharomyces cerevisiae,Biochim Biophys Acta 3:239-253, 1999; Kopecka et al., A method of isolating anucleated yeast protoplasts unable to synthesize the glucan fibrillar component of the wall J Gen Microbiol 81:111-120, 1974; and Yoo et al., Fission yeast Hrp1, a chromodomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation, Nucl Acids Res 28:2004-2011, 2000. Cell division in yeast is reviewed by Gould and Simanis, The control of septum formation in fission yeast, Genes & Dev 11:2939-51, 1997).
• I.C. Archeabacterial Minicells[0233]
• The term “archeabacterium” is defined as is used in the art and includes extreme thermophiles and other Archaea. Woese, C. R., L. Magrum. G. Fox. 1978. Archeabacteria. Journal of Molecular Evolution. 11:245-252. Three types of Archeabacteria are halophiles, thermophiles and methanogens. By physiological definition, the Archaea (informally, archaes) are single-cell extreme thermophiles (including thermoacidophiles), sulfate reducers, methanogens, and extreme halophiles. The thermophilic members of the Archaea include the most thermophilic organisms cultivated in the laboratory. The aerobic thermophiles are also acidophilic; they oxidize sulfur in their environment to sulfuric acid. The extreme halophiles are aerobic or microaerophilic and include the most salt tolerant organisms known. The sulfate-reducing Archaea reduce sulfate to sulfide in extreme environment. Methanogens are strict anaerobes, yet they gave rise to at least two separate aerobic groups: the halophiles and a thermoacidophilic lineage (Olsen, G., http://www.bact.wisc.edu/microtextbook/). Non-limiting examples of halophiles include[0234]Halobacterium cutirubrumandHalogerax mediterranei.Non-limiting examples of methanogens includeMethanococcus voltae; Methanococcus vanniela; Methanobacterium thermoautotrophicum; Methanococcus voltae; Methanothermus fervidus;andMethanosarcina barkeri.Non-limiting examples of thermophiles includeAzotobacter vinelandii; Thermoplasma acidophilum; Pyrococcus horikoshii; Pyrococcus furiosus;and Crenarchaeota (extremely thermophilic archaebacteria) species such asSulfolobus solfataricusandSulfolobus acidocaldarius.
• Archeabacterial minicells are within the scope of the invention. Archeabacteria have homologs of eubacterial minicell genes and proteins, such as the MinD polypeptide from[0235]Pyrococcus furiosus.(Hayashi et al., EMBO J 2001 20:1819-28, Structural and functional studies of MinD ATPase: implications for the molecular recognition of the bacterial cell division apparatus). It is thus possible to create Archeabacterial minicells by methods such as, by way of non-limiting example, overexpressing the product of a min gene isolated from a prokaryote or an archeabacterium; or by disrupting expression of a min gene in an archeabacterium of interest by, e.g., the introduction of mutations thereof or antisense molecules thereto. See, e.g., Laurence et al., Nucleoid Structure and Partition inMethanococcus jannaschii:An Archaeon With Multiple Copies of the Chromosome, Genetics 152:1315-1323, 1999.
• In one aspect, the invention is drawn to archael minicells. By physiological definition, the Archaea (informally, archaes) are single-cell extreme thermophiles (including thermoacidophiles), sulfate reducers, methanogens, and extreme halophiles. The thermophilic members of the Archaea include the most thermophilic organisms cultivated in the laboratory. The aerobic thermophiles are also acidophilic; they oxidize sulfur in their environment to sulfuric acid. The extreme halophiles are aerobic or microaerophilic and include the most salt tolerant organisms known. The sulfate-reducing Archaea reduce sulfate to sulfide in extreme environment. Methanogens are strict anaerobes, yet they gave rise to at least two separate aerobic groups: the halophiles and a thermoacidophilic lineage (Olsen, G., http://www.bact.wisc.edu/microtextbook/).[0236]
• I.D. Minicells Produced from Diverse Organisms[0237]
• There are genes that can be disrupted to cause minicell production that are conserved among the three Kingdoms. For example, SMC (structural maintenance of chormosomes) proteins are conserved among prokaryotes, archeabacteria and eukaryotes (Hirano, SMC-mediated chromosome and mechanics: a conserved scheme from bacteria to vertebrates?, Genes and Dev. 13:11-19, 1999; Holmes et al., Closing the ring: Links between SMC proteins and chromosome partitioning, condensation, and supercoiling, PNAS 97:1322-1324, 2000; Michiko and Hiranol, EMBO J 17:7139-7148, 1998, ATP-dependent aggregation of single-stranded DNA by a bacterial SMC homodimer, 1998). Mutations in[0238]B. subtilissmc genes result in the production of minicells (Britton et al., Characterization of a eubacterial smc protein involved in chromosome partitioning, Genes and Dev. 12:1254-1259, 1998; Moriya et al., ABacillus subtilisgene-encoding protein homologous to eukaryotic SMC motor protein is necessary for chromosome partition Mol Microbiol 29:179-87, 1998). Disruption of smc genes in various cells is predicted to result in minicell production therefrom.
• As another example, mutations in the yeast genes encoding TRF topoisomerases result in the production of minicells, and a human homolog of yeast TRF genes has been stated to exist (Castano et al., A novel family of TRF (DNA topoisomerase I-related function) genes required for proper nuclear segregation, Nucleic Acids Res 24:2404-10, 1996). Mutations in a yeast chromodomain ATPase, Hrp1, result in abnormal chromosomal segregation; (Yoo et al., “Fission yeast Hrp1, a chromogomain ATPase, is required for proper chromosome segregation and its overexpression interferes with chromatin condensation,” Nuc. Acids Res. 28:2004-2001). Disruption of TRF and/or Hrp1 function is predicted to cause minicell production in various cells. Genes involved in septum formation in fission yeast (see, e.g., Gould et al., “The control of septum formation in fission yeast,” Genes and Dev. 11:2939-2951, 1997) can be used in like fashion.[0239]
• As another example, mutations in the divIVA gene of[0240]Bacillus subtilisresults in minicell production (Table 2). When expressed inE. colior the yeastSchizosaccharomyces pombe,aB. subtilisDivIVA-GFP protein is targeted to cell division sites therein, even though clear homologs of DivIVA do not seem to exist inE. coliorS. pombe(David et al., Promiscuous targeting ofBacillus subtiliscell division protein DivIVA to division sites inEscherichia coliand fission yeast, EMBO J 19:2719-2727, 2000.) Over- or under-expression ofB. subtilisDivIVA or a homolog thereof may be used to reduce minicell production in a variety of cells.
• II. Production of Minicells[0241]
• Eubacterial minicells are produced by parent cells having a mutation in, and/or overexpressing, or under expressing a gene involved in cell division and/or chromosomal partitioning, or from parent cells that have been exposed to certain conditions, that result in abberant fission of bacterial cells and/or partitioning in abnormal chromosomal segregation during cellular fission (division). The term “parent cells” or “parental cells” refers to the cells from which minicells are produced. Minicells, most of which lack chromosomal DNA (Mulder et al., The[0242]Escherichia coliminB mutation resembles gyrB in Defective nucleoid segregation and decreased negative supercoiling of plasmids. Mol Gen Genet, 1990, 221: 87-93), are generally, but need not be, smaller than their parent cells. Typically, minicells produced fromE. colicells are generally spherical in shape and are about 0.1 to about 0.3 um in diameter, whereas wholeE. colicells are about from about 1 to about 3 um in diameter and from about about 2 to about 10 um in length. Micrographs ofE. colicells and minicells that have been stained with DAPI (4:6-diamidino-z-phenylindole), a compound that binds to DNA, show that the minicells do not stain while the parentE. coliare brightly stained. Such micrographs demonstrate the lack of chromosomal DNA in minicells. (Mulder et al., Mol. Gen. Genet. 221:87-93, 1990).
• As shown in Table 2, minicells are produced by several different mechanisms such as, by way of non-limiting example, the over expression of genes involved in chromosomal replication and partitioning, mutations in such genes, and exposure to various environmental conditions. “Overexpression” refers to the expression of a polypeptide or protein encoded by a DNA introduced into a host cell, wherein the polypeptide or protein is either not normally present in the host cell, or wherein the polypeptide or protein is present in the host cell at a higher level than that normally expressed from the endogenous gene encoding the polypeptide or protein. For example, in[0243]E. colicells that overexpress the gene product FtsZ (The FtsZ gene encodes a protein that is involved in regulation of divisions; see Cook and Rothfield, Early stages in development of theEscherichia colicell-division site. Mol Microbiol, 1994. 14: p. 485-495; and Lutkenhaus, Regulation of cell division inE. coli.Trends Genet, 1990. 6: p. 22-25), there is an increase in the formation of minicells (Begg et al., Roles of FtsA and FtsZ in the activation of division sites. J. Bacteriology, 1997. 180: 881-884). Minicells are also produced byE. colicells having a mutation in one or more genes of the min locus, which is a group of genes that encode proteins that are involved in cell division (de Boer et al., Central role for theEscherichia coliminC gene product in two different cell division-inhibition systems. Proc. Natl. Acad. Sci. USA, 1990. 87: 1129-33; Akerlund et al., Cell division inEscherichia coliminB mutants. Mol Microbiol, 1992. 6: 2073-2083).
• Prokaryotes that have been shown to produce minicells include species of Escherichia, Shigella, Bacillus, Lactobacillus, and Campylobacter. Bacterial minicell-producing species of particular interest are[0244]E. coliandBacillus subtilis. E. coliis amenable to manipulation by a variety of molecular genetic methods, with a variety of well-characterized expression systems, including many episomal expression systems, factors and elements useful in the present invention.B. subtilis,also amenable to genetic manipulation using episomal expression elements, is an important industrial organism involved in the production of many of the world's industrial enzymes (proteases, amylases, etc.), which it efficiently produces and secretes.
• In the case of other eubacterial species, homologs of[0245]E. coliorB. subilisgenes that cause minicell production therein are known or can be identified and characterized as is known in the art. For example, the min regions of the chromosome ofStrepococcus pneumoniaeandNeisseria gonorrhoeaehave been characterized (Massidda et al., Unconventional organization of the division and cell wall gene cluster ofStreptococcus pneumoniae,Microbiology 144:3069-78, 1998; and Ramirez-Arcos et al., Microbiology 147:225-237, 2001 and Szeto et al., Journal of Bacteria 183(21):6253, 2001, respectively). Those skilled in the art are able to isolate minicell producing (min) mutants, or prepare compounds inhibitory to genes that induce a minicell production (e.g., antisense to min transcripts).

  TABLE 2
  Eubacterial Strains, Mutations and Conditions that Promote Minicell Formation

  Species	Strain	Notes	References
  Campylobacter jejuni		may occur naturally late in growth	Brock et al., 1987
  		cycle
  Bacillus subtilis		Mutations in divIVB locus (inc.	Barak et al., 1999
  		minC, minD
  		ripX mutations	Sciochetti et al., 1999;
  			Lemon et al., 2001
  		smc mutations	Moriya et al., 1998; Britton
  			et al., 1998
  		oriC deletions	Moriya et al., 1997; Hassan
  			et al., 1997
  		prfA mutations	Pederson and Setlow, 2001
  		Mutations in divIVA locus	Cha et al., 1997
  	B.s. 168	ts initiation mutation TsB143	Sargent, 1975
  Bacillus cereus	WSBC	Induced by exposure to long-chain	Maier et al., 1999
  	10030	polyphosphate
  Shigella flexneri(2a)	MC-1		Gemski et al., 1980
  S. dysenteriae(1)	MC-V		Gemski et al., 1980
  Lactobacillus spp.		Variant minicell-producing strains	Pidoux et al., 1990
  		isolated from grains
  Neisseria gonorrhoeae		deletion or overepression of min	Ramirez-Arcos et al., 2001;
  		homologues	Szeto et al., 2001
  Escherichia coli		MinA mutations	Frazer et al., 1975; Cohen et
  			al. 1976
  		MinB mutations and deletions	Adler et al., 1967; Davie et
  			al., 1984; Schaumberg et
  			al.; 1983; Jaffe et al., 1988;
  			Akerlund et al., 1992
  	CA8000	cya, crp mutations	Kumar et al.; 1979
  		MukA1 mutation	Hiraga et al., 1996
  		MukE, mukF mutations	Yamanaka et al., 1996
  		hns mutation	Kaidow et al., 1995
  	DS410		Heighway et al., 1989
  		χ1972, χ1776 and χ2076	Curtiss, 1980
  	P678-54	Temperature-sensitive cell division	Adler et al. 1967; Allen et
  		mutations	al., 1972; Hollenberg et al.,
  			1976
  		Induced by overexpression of minB	De Boer et al., 1988
  		protein
  		Induced by overexpression of minE	Pichoff et al., 1995
  		protein or derivatives
  		Induced by oveproduction of ftsZ	Ward et al., 1985
  		gene
  		Induced by overexpression of sdiA	Wang et al., 1991
  		gene
  		Induced by overexpression of min	Ramirez-Arcos et al., 2001;
  		genes fromNeisseria gonorrhoeae	Szeto et al., 2001
  		Induced by exposure to EGTA	Wachi et al., 1999
  Legionella Pneumophila		Induced by exposure to ampicillin	Elliot et al., 1985

• Citations for Table 2:[0246]
• Adler et al.,[0247]Proc. Natl. Acad.Sci.57:321-326 (1967)
• Akerlund et al.,[0248]Mol. Microbiol.6:2073-2083 (1992)
• Allen et al.,[0249]Biochem. Biophys. Res. Communi.47:1074-1079 (1972)
• Barak et al.,[0250]J. Bacteriol.180:5237-5333 (1998)
• Britton et al.,[0251]Genes Dev.12:1254-9 (1998)
• Brock et al.,[0252]Can. J. Microbiol.33:465-470 (1987)
• Cha et al.,[0253]J. Bacteriol.179:1671-1683 (1997)
• Cohen et al.,[0254]Genetics56:550-551 (1967)
• Curtiss, Roy III, U.S. Pat. No. 4,190,495; Issued Feb. 26, 1980[0255]
• Davie et al.,[0256]J. Bacteriol.170:2106-2112 (1988)
• Elliott et al.,[0257]J. Med. Microbiol,19:383-390 (1985)
• Frazer et al.,[0258]Curr. Top. Immunol.69:1-84 (1975)
• Gemski et al.,[0259]Infect. Immun.30:297-302 (1980)
• Hassan et al.,[0260]J. Bacteriol.179:2494-502 (1997)
• Heighway et al.,[0261]Nucleic Acids Res.17:6893-6901 (1989)
• Hiraga et al.,[0262]J. Bacteriol.177:3589-3592 (1995)
• Hollenberg et al., Gene 1:33-47 (1976)[0263]
• Kumar et al.,[0264]Mol. Gen. Genet.176:449-450 (1979)
• Lemon et al.,[0265]Proc. Natl. Acad. Sci. USA98:212-7 (2001)
• Maier et al.,[0266]Appl. Environ. Microbiol.65:3942-3949 (1999)
• Moriya et al.,[0267]DNA Res4:115-26 (1997)
• Moriya et al.,[0268]Mol. Microbiol.29:179-87 (1998)
• Markiewicz et al.,[0269]FEMS Microbiol. Lett.70:119-123 (1992)
• Pederson and Setlow,[0270]J. Bacteriol.182:1650-8 (2001)
• Pichoff et al.,[0271]Mol. Microbiol.18:321-329 (1995)
• Pidoux et al.,[0272]J. App. Bacteriol.69:311-320 (1990)
• Ramirez-Arcos et al.[0273]Microbiol.147:225-237 (2001)
• Sargent M. G.,[0274]J. Bacteriol.123:1218-1234 (1975)
• Sciochetti et al.,[0275]J. Bacteriol.181:6053-62 (1999)
• Schaumberg et al.,[0276]J. Bacteriol.153:1063-1065 (1983)
• Szeto et al.,[0277]Jour. of Bacter.183 (21):6253 (2001)
• Wachi et al.,[0278]Biochimie81:909-913 (1999)
• Wang et al.,[0279]Cell42:941-949 (1985)
• Yamanaka et al.,[0280]Mol. Gen. Genet.250:241-251 (1996)
• II.A. Optimized Minicell Construction[0281]
• Minicells are produced by several different eubacterial strains and mechanisms including the overexpression of endogenous or exogenous genes involved in cell division, chromosomal replication and partitioning, mutations in such genes, and exposure to various chemical and/or physical conditions. For example, in[0282]E. colicells that overexpress the gene product FtsZ (the ftsZ gene encodes a protein that is involved in regulation of cell division; see Cook and Rothfield, Early stages in development of theEscherichia colicell-division site. Mol Microbiol, 1994. 14: p. 485-495; and Lutkenhaus, Regulation of cell division inE. coli.Trends Genet, 1990. 6: p. 22-25), there is an increase in the formation of minicells (Begg et al., Roles of FtsA and FtsZ in the activation of division sites. J. Bacteriology, 1997. 180: 881-884). Minicells are also produced byE. colicells having a mutation in one or more genes of the min locus, which is a group of genes that encode proteins that are involved in cell division (de Boer et al., Central role for theEscherichia coliminC gene product in two different cell division-inhibition systems. Proc. Natl. Acad. Sci. USA, 1990. 87: 1129-33; Akerlund et al., Cell division inEscherichia coliminB mutants. Mol Microbiol, 1992. 6: 2073-2083).
• Eubacterial cells that have been shown to produce minicells include, but are not limited to species of Escherichia, Shigella, Bacillus, Lactobacillus, Legionella and Campylobacter. Bacterial minicell-producing species of particular interest are[0283]E. coliandBacillus subtilis.These organisms are amenable to manipulation by a variety of molecular and genetic methods, with a variety of well-characterized expression systems, including many episomal and chromosomal expression systems, as well as other factors and elements useful in the present invention.
• The following sections describe genes that may be manipulated so as to stimulate the production of minicells. The invention may include any of these non-limiting examples for the purpose of preparing minicells. Furthermore, these genes and gene products and conditions, may be used in methodologies to identify other gene(s), gene products, biological events, biochemical events, or physiological events that induce or promote the production of minicells. These methodologies include, but are not limited to genetic selection, protein, nucleic acid, or combinatorial chemical library screen, one- or two-hybrid analysis, display selection technologies, e.g. phage or yeast display, hybridization approaches, e.g. array technology, and other high- or low-throughput approaches.[0284]
• II. A.1. Homologs[0285]
• Homologs of these genes and gene products from other organisms may also be used. As used herein, a “homolog” is defined is a nucleic acid or protein having a nucleotide sequence or amino acid sequence, respectively, that is “identical,” “essentially identical,” “substantially identical,” “homologous” or “similar” (as described below) to a reference sequence which may, by way of non-limiting example, be the sequence of an isolated nucleic acid or protein, or a consensus sequence derived by comparison of two or more related nucleic acids or proteins, or a group of isoforms of a given nucleic acid or protein. Non-limiting examples of types of isoforms include isoforms of differing molecular weight that result from, e.g., alternate RNA splicing or proteolytic cleavage; and isoforms having different post-translational modifications, such as glycosylation; and the like.[0286]
• Two sequences are said to be “identical” if the two sequences, when aligned with each other, are exactly the same with no gaps, substitutions, insertions or deletions.[0287]
• Two sequences are said to be “essentially identical” if the following criteria are met. Two amino acid sequences are “essentially identical” if the two sequences, when aligned with each other, are exactly the same with no gaps, insertions or deletions, and the sequences have only conservative amino acid substitutions. Conservative amino acid substitutions are as described in Table 3.[0288]

  TABLE 3
  CONSERVATIVE AMINO ACID SUBSTITUTIONS

  Type of Amino	Groups of Amino Acids that Are Conservative
  Acid Side Chain	Substitutions Relative to Each Other
  Short side chain	Glycine, Alanine, Serine, Threonine and Methionine
  Hydrophobic	Leucine, Isoleucine and Valine
  Polar	Glutamine and Asparagine
  Acidic	Glutamic Acid and Aspartic Acid
  Basic	Arginine, Lysine and Histidine
  Aromatic	Phenylalanine, Tryptophan and Tyrosine

• Two nucleotide sequences are “essentially identical” if they encode the identical or essentially identical amino acid sequence. As is known in the art, due to the nature of the genetic code, some amino acids are encoded by several different three base codons, and these codons may thus be substituted for each other without altering the amino acid at that position in an amino acid sequence. In the genetic code, TTA, TTG, CTT, CTC, CTA and CTG encode Leu; AGA, AGG, CGT, CGC, CGA and CGG encode Arg; GCT, GCC, GCA and GCG encode Ala; GGT, GGC, GGA and GGG encode Gly; ACT, ACC, ACA and ACG encode Thr; GTT, GTC, GTA and GTG encode Val; TCT, TCC, TCA and TCG encode Ser; CCT, CCC, CCA and CCG encode Pro; ATA, ATC and ATA encode Ile; GAA and GAG encode Glu; CAA and CAG encode Gln; GAT and GAC encode Asp; AAT and AAC encode Asn; AGT and AGC encode Ser; TAT and TAC encode Tyr; TGT and TGC encode Cys; AAA and AAG encode Lys; CAT and CAC encode His; TTT and TTC encode Phe, TGG encodes Trp; ATG encodes Met; and TGA, TAA and TAG are translation stop codons.[0289]
• Two amino acid sequences are “substantially identical” if, when aligned, the two sequences are, (i) less than 30%, preferably ≦20%, more preferably ≦15%, most preferably ≦10%, of the identities of the amino acid residues vary between the two sequences; (ii) the number of gaps between or insertions in, deletions of and/or subsitutions of, is ≦10%, more preferably ≦5%, more preferably ≦3%, most preferably ≦1%, of the number of amino acid residues that occur over the length of the shortest of two aligned sequences.[0290]
• Two sequences are said to be “homologous” if any of the following criteria are met. The term “homolog” includes without limitation orthologs (homologs having genetic similarity as the result of sharing a common ancestor and encoding proteins that have the same function in different species) and paralog (similar to orthologs, yet gene and protein similarity is the result of a gene duplication).[0291]
• One indication that nucleotide sequences are homologous is if two nucleic acid molecules hybridize to each other under stringent conditions. Stringent conditions are sequence dependent and will be different in different circumstances. Generally, stringent conditions are selected to be about 5° C. lower than the thermal melting point (Tm) for the specific sequence at a defined ionic strength and pH. The Tm is the temperature (under defined ionic strength and pH) at which 50% of the target sequence hybridizes to a perfectly matched probe. Typically, stringent conditions will be those in which the salt concentration is about 0.02 M at pH 7 and the temperature is at least about 60° C.[0292]
• Another way by which it can be determined if two sequences are homologous is by using an appropriate algorithm to determine if the above-described criteria for substantially identical sequences are met. Sequence comparisons between two (or more) polynucleotides or polypeptides are typically performed by algorithms such as, for example, the local homology algorithm of Smith and Waterman (Adv. Appl. Math. 2:482, 1981); by the homology alignment algorithm of Needleman and Wunsch (J. Mol. Biol. 48:443, 1970); by the search for similarity method of Pearson and Lipman (Proc. Natl. Acad. Sci. U.S.A. 85:2444, 1988); and by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, version 10.2 Genetics Computer Group (GCG), 575 Science Dr., Madison, Wis.); BLASTP, BLASTN, and FASTA (Altschul et al., J. Mol. Biol. 215:403-410, 1990); or by visual inspection.[0293]
• Optimal alignments are found by inserting gaps to maximize the number of matches using the local homology algorithm of Smith and Waterman (1981) Adv. Appl. Math. 2:482-489. “Gap” uses the algorithm of Needleman and Wunsch (1970 J Mol. Biol. 48:443-453) to find the alignment of two complete sequences that maximizes the number of matches and minimizes the number of gaps. In such algorithms, a “penalty” of about 3.0 to about 20 for each gap, and no penalty for end gaps, is used.[0294]
• Homologous proteins also include members of clusters of orthologous groups of proteins (COGs), which are generated by phylogenetic classification of proteins encoded in complete genomes. To date, COGs have been delineated by comparing protein sequences encoded in 43 complete genomes, representing 30 major phylogenetic lineages. Each COG consists of individual proteins or groups of paralogs from at least 3 lineages and thus corresponds to an ancient conserved domain (see Tatusov et al., A genomic perspective on protein families. Science, 278: 631-637, 1997; Tatusov et al., The COG database: new developments in phylogenetic classification of proteins from complete genomes, Nucleic Acids Res. 29:22-28, 2001; Chervitz et al., Comparisn of the Complete Sets of Worm and Yeast: Orthology and Divergence, Science 282:2022-2028, 1998; and http://www.ncbi.nlm.nih.gov/COG/).[0295]
• The entirety of two sequences may be identical, essentially identical, substantially identical, or homologous to one another, or portions of such sequences may be identical or substantially identical with sequences of similar length in other sequences. In either case, such sequences are similar to each other. Typically, stretches of identical or essentially within similar sequences have a length of ≧12, preferably ≧24, more preferably ≧48, and most preferably ≧96 residues.[0296]
• II.A.2.[0297]Escherichia coliGenes
• Exemplary genes and gene products from[0298]E. colithe expression and/or sequence of which can be manipulated so as to stimulate minicell production inE. colior any other organism, as can homologs thereof from any species, include without limitation, the bolA gene (Aldea, M., et al. 1988. Identification, cloning, and expression of bolA, an ftsZ-dependent morphogene ofEscherichia coli.J. Bacteriol. 170:5196-5176; Aldea, M., et al. 1990. Division genes inEscherichia coliare expressed coordinately to cell septum requirements by gearbox promoters. EMBO J. 9:3787-3794); the chpA gene (Masuda, Y., et al. 1993. chpA and chpB,Escherichia colichromosomal homologs of the pem locus responsible for stable maintenance of plasmid R100. J. Bacteriol. 175:6850-6856); the chpB gene (Masuda, Y., et al. 1993. chpA and chpB,Escherichia colichromosomal homologs of the pem locus responsible for stable maintenance of plasmid R100. J. Bacteriol. 175:6850-6856); the chpR (chpAI) gene (Masuda, Y., et al. 1993. chpA and chpB,Escherichia colichromosomal homologs of the pem locus responsible for stable maintenance of plasmid R100. J. Bacteriol. 175:6850-6856); the chpS (chpBI)gene (Masuda, Y., et al. 1993. chpA and chpB,Escherichia colichromosomal homologs of the pem locus responsible for stable maintenance of plasmid R100. J. Bacteriol. 175:6850-6856); the crg gene (Redfield, R. J., and A. M. Campbell. 1987. Structurae of cryptic lambda prophages. J. Mol. Biol. 198:393-404); the crp gene (Kumar, S., et al. 1979. Control of minicell producing cell division by cAMP-receptor protein complex inEscherichia coli.Mol. Gen. Genet. 176:449-450); the cya gene (Kumar, S., et al. 1979. Control of minicell producing cell division by cAMP-receptor protein complex inEscherichia coli.Mol. Gen. Genet. 176:449-450); the dicA gene (Labie, C., et al. 1989. Isolation and mapping ofEscherichia colimutations conferring resistance to division inhibition protein DicB. J. Bacteriol. 171:4315-4319); the dicB gene (Labie, C., et al. 1989. Isolation and mapping ofEscherichia colimutations conferring resistance to division inhibition protein DicB. J. Bacteriol. 171:4315-4319; Labie, C., et al. 1990. Minicell-forming mutants ofEscherichia coli:suppression of both DicB- and MinD-dependent division inhibition by inactivation of the minC gene product. J. Bacteriol. 1990. 172:5852-5858); the dicC gene (Bejar, S., et al. 1988. Cell division inhibition gene dicB is regulated by a locus similar to lambdoid bacteriophage immunity loci. Mol. Gen. Genet. 212:11-19); the dicF gene (Tetart, F., and J. P. Bouche. 1992. Regulation of the expression of the cell-cycle gene ftsZ by DicF antisense RNA. Division does not require a fixed number of FtsZ molecules. Mol. Microbiol. 6:615-620); the dif gene (Kuempel, P. L., et al. 1991. dif, a recA-independent recombination site in the terminus region of the chromosome ofEscherichia coli.New Biol. 3:799-811); the dksA gene (Yamanaka, K., et al. 1994. Cloning, sequencing, and characterization of multicopy suppressors of a mukB mutation inEscherichia coli.Mol. Microbiol. 13:301-312); the dnaK gene (Paek, K. H., and G. C. Walker. 1987.Escherichia colidnaK null mutants are inviable at high temperature. J. Bacteriol. 169:283-290); the dnaJ gene (Hoffman, H. J., et al. 1992. Activity of the Hsp70 chaperone complex—DnaK, DnaJ, and GrpE—in initiating phage lambda DNA replication by sequestering and releasing lambda P protein. Proc. Natl. Acad. Sci. 89:12108-12111); the fcsA gene (Kudo, T., et al. 1977. Characteristics of a cold-sensitive cell division mutantEscherichia coliK-12. Agric. Biol. Chem. 41:97-107); the fic gene (Utsumi, R., et al. 1982. Involvement of cyclic AMP and its receptor protein in filamentation of anEscherichia colific mutant. J. Bacteriol. 151:807-812; Komano, T., et al. 1991. Functional analysis of the fic gene involved in regulation of cell division. Res. Microbiol. 142:269-277); the fis gene (Spaeny-Dekking, L. et al. 1995. Effects of N-terminal deletions of theEscherichia coliprotein Fis on the growth rate, tRNA (2Ser) expression and cell morphology. Mol. Gen. Genet. 246:259-265); the ftsA gene (Bi, E., and J. Lutkenhaus. 1990. Analysis of ftsZ mutations that confer resistance to the cell division inhibitor SulA (SfiA). J. Bacterial. 172:5602-5609; Dai, K, and J. Lutkenhaus. 1992. The proper ration of FtsZ to FtsA is required for cell division to occur inEscherichia coli.J. Bacteriol. 174:6145-6151); the ftsE gene (Taschner, P. E. et al. 1988. Division behavior and shape changes in isogenic ftsZ, ftsQ, ftsA, pbpB, and ftsE cell division mutants ofEscherichia coliduring temperature shift experiments. J. Bacteriol. 170:1533-1540); the ftsH gene (Ogura, T. et al. 1991. Structure and function of the ftsH gene inEscherichia coli.Res. Microbiol. 142:279-282); the ftsI gene (Begg, K. J., and W. D. Donachie. 1985. Cell shape and division inEscherichia coli:experiments with shape and division mutants. J. Bacteriol. 163:615-622); the ftsJ gene (Ogura, T. et al. 1991. Structure and function of the ftsH gene inEscherichia coli.Res. Microbiol. 142:279-282); the ftsL gene (Guzman, et al. 1992. FtsL, an essential cytoplasmic membrane protein involved in cell division inEscherichia coli.J. Bacteriol. 174:7716-7728); the ftsN gene (Dai, K. et al. 1993. Cloning and characterization of ftsN, an essential cell division gene inEscherichia coliisolated as a multicopy suppressor of ftsA12(Ts). J. Bacteriol. 175:3790-3797); the ftsQ gene (Wang, X. D. et al. 1991. A factor that positively regulates cell division by activating transcription of the major cluster of essential cell division genes ofEscherichia coli.EMBO J. 10:3362-3372); the ftsW gene (Khattar, M. M. et al. 1994. Identification of FtsW and characterization of a new ftsW division mutant ofEscherichia coli.J. Bacteriol. 176:7140-7147); the ftsX (ftsS) gene (Salmond, G. P. and S. Plakidou. 1984. Genetic analysis of essential genes in the ftsE region of theEscherichia coligenetic map and identification of a new cell division gene, ftsS. Mol. Gen. Genet. 197:304-308); the ftsY gene (Gill, D. R. and G. P. Salmond. 1990. The identification of theEscherichia coliftsY gene product: an unusual protein. Mol. Microbiol. 4:575-583); the ftsZ gene (Ward, J. E., and J. Lutkenhaus. 1985. Overproduction of FtsZ induces minicell formation. Cell. 42:941-949; Bi, E., and J. Lutkenhaus. 1993. Cell division inhibitors SulA and MinCD prevent formation of the FtsZ ring. J. Bacteriol. 175:1118-1125); the gyrB gene (Mulder, E., et al. 1990. TheEscherichia coliminB mutation resembles gyrB in defective nucleoid segregation and decreased negative supercoiling of plasmids. Mol. Gen. Genet. 221:87-93); the hlfB (ftsH)gene (Herman, C., et al. 1993. Cell growth and lambda phage development controlled by the same essentialEscherichia coligene, ftsH/hflB. Proc. Natl. Acad. Sci. 90:10861-10865); the hfq gene (Takada, A., et al. 1999. Negative regulatory role of theEscherichia colihfq gene in cell division. Biochem. Biophys. Res. Commun. 266:579-583; the hipA gene (Scherrer, R., and H. S. Moyed. 1988. Conditional impairment of cell division and altered lethality in hipA mutants ofEscherichia coliK-12. J. Bacteriol. 170:3321-3326); the hipB gene (Hendricks, E. C., et al. 2000. Cell division, guillotining of dimer chromosomes and SOS induction in resolution mutants (dif, xerC and xerD) ofEscherichia coli.Mol. Microbiol. 36:973-981); the hns gene (Kaidow, A., et al. 1995. Anucleate cell production byEscherichia colidelta hns mutant lacking a histone-like protein, H-NS. J. Bacteriol. 177:3589-3592); the htrB gene (Karow, M., et al. 1991. Complex phenotypes of null mutations in the htr genes, whole products are essential forEscherichia coligrowth at elevated temperatures. Res. Microbiol. 142:289-294); the lpxC (envA)gene (Beall, B., and J. Lutkenhaus. 1987. Sequence analysis, transcriptional organization, and insertional mutagenesis of the envA gene ofEscherichia coli.J. Bacteriol. 169:5408-5415; Young, K., et al. 1995. The envA permeability/cell division gene ofEscherichia coliencodes the second enzyme of lipid A biosynthesis. UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase. J. Biol. Chem. 270:30384-30391); the malE gene (Pichoff, S., et al. 1997. MinCD-independent inhibition of cell division by a protein that fuses MalE to the topological specificity factor MinE. J. Bacteriol. 179:4616-4619); the minA gene (Davie, E., et al. 1984. Genetic basis of minicell formation inEscherichia coliK-12. J. Bacteriol. 158:1202-1203); the minB gene (Davie, E., et al. 1984. Genetic basis of minicell formation inEscherichia coliK-12. J. Bacteriol. 158:1202-1203); the minC gene (de Boer, P. A., et al. 1990. Central role for theEscherichia coliminC gene product in two different cell division-inhibition systems. Proc. Natl. Acad. Sci. 87:1129-1133); the minD gene (Labie, C., et al. 1990. Minicell-forming mutants ofEscherichia coli:suppression of both DicB- and MinD-dependent division inhibition by inactivation of the minC gene product. J. Bacteriol. 172:5852-5855; Hayashi, I., et al. 2001. Structural and functional studies of MinD ATPase: implications for the molecular recognition of the bacterial cell division apparatus. EMBO J. 20:1819-1828); the minE gene (de Boer, P. A., et al. 1989. A division inhibitor and a topological specificity factor coded for by the minicell locus determine proper placement of the division septum inE. coli.Cell. 56:641-649); the mreB gene (Doi, M., et al. 1988. Determinations of the DNA sequence of the mreB gene and of the gene products of the mre region that function in formation of the rod shape ofEscherichia colicells. J. Bacteriol. 170:4619-4624); the mreC gene (Wachi, M., et al. 1989. New mre genes mreC and mreD, responsible for formation of the rod shape ofEscherichia colicells. J. Bacteriol. 171:6511-6516); the mreD gene (Wachi, M., et al. 1989. New mre genes mreC and mreD, responsible for formation of the rod shape ofEscherichia colicells. J. Bacteriol. 171:6511-6516); the mukA gene (Hiraga, S., et al. 1989. Chromosome partitioning inEscherichia coli:novel mutants producing anucleate cells. J. Bacteriol. 171:1496-1505); the mukB gene (Hiraga, S., et al. 1991. Mutants defective in chromosome partitioning inE. coli.Res. Microbiol. 142:189-194); the mukE gene (Yamanaka, K., et al. 1996. Identification of two new genes, mukE and mukF, involved in chromosome partitioning inEscherichia coli.Mol. Gen. Genet. 250:241-251; Yamazoe, M., et al. 1999. Complex formation of MukB, MukE and MukF proteins involved in chromosome partitioning inEscherichia coli.EMBO J. 18:5873-5884); the mukF gene (Yamanaka, K., et al. 1996. Identification of two new genes, mukE and mukF, involved in chromosome partitioning inEscherichia coli.Mol. Gen. Genet. 250:241-251; Yamazoe, M., et al. 1999. Complex formation of MukB, MukE and MukF proteins involved in chromosome partitioning inEscherichia coli.EMBO J. 18:5873-5884); the parC gene (Kato, J., et al. 1988. Gene organization in the region containing a new gene involved in chromosome partition inEscherichia coli.J. Bacteriol. 170:3967-3977); the parE gene (Roberts, R. C., et al. 1994. The parDE operon of the broad-host-range plasmid RK2 specifies growth inhibition associated with plasmid loss. J. Mol. Biol. 237:35-51); the pbpA gene (Rodriguez, M. C., and M. A. de Pedro. 1990. Initiation of growth in pbpAts and rodAts mutants ofEscherichia coli.FEMS Microbiol. Lett. 60:235-239); the pcnB gene (Makise, M., et al. 1999. Identification of a high-copy-number plasmid suppressor of a lethal phenotype caused by mutant DnaA protein which has decreased intrinsic ATPase activity. Biol. Pharm. Bull. 22:904-909); the parF (plsC inE. coli) gene product from Salmonella (Luttinger, A. L., et al. 1991. A cluster of genes that affects nucleoid segregation inSalmonella typhimurium.New Biol. 3:687-697); the rpoS gene (Cam, K., et al. 1995. Sigma S-dependent overexpression of ftsZ in anEscherichia coliK-12 rpoB mutant that is resistant to the division inhibitors DicB and DicF RNA. Mol. Gen. Genet. 248:190-194); the rcsB gene (Gervais, F. G., et al. 1992. The rcsB gene, a positive regulator of colanic acid biosynthesis inEscherichia coli,is also an activator of ftsZ expression. J. Bacteriol. 174:3964-3971); the rcsF gene (Gervais, F. G., and G. R. Drapeau. 1992. Identification, cloning, and characterization of rcsF, a new regulator gene for exopolysaccharide synthesis that suppresses the division mutation ftsZ84 inEscherichia coliK-12. J. Bacteriol. 174:8016-8022); the rodA gene (Rodriguez, M. C., and M. A. de Pedro. 1990. Initiation of growth in pbpAts and rodAts mutants ofEscherichia coli.FEMS Microbiol. Lett. 60:235-239); the sdia (sulB, sfIB) gene (Wang, X. D., et al. 1991. A factor that positively regulates cell division by activating transcription of the major cluster of essential cell division genes ofEscherichia coli.EMBO J. 10:3363-3372); the sefA (fabZ) gene (Mohan, S., et al. 1994. AnEscherichia coligene (FabZ) encoding (3R)-hydroxymyristoyl acyl carrier protein dehydrase. Relation to fabA and suppression of mutations in lipid A biosynthesis. J. Biol Chem. 269:32896-32903); the sfiC gene (D'Ari, R., and 0. Huisman. 1983. Novel mechanism of cell division inhibition associated with the SOS response inEscherichia coli.J. Bacteriol. 156:243-250); the sulA gene (Bi, E., and J. Lutkenhaus. 1990. Interaction between the min locus and ftsZ. J. Bacteriol. 172:5610-5616; Bi, E., and J. Lutkenhaus. 1993. Cell division inhibitors SulA and MinCD prevent formation of the FtsZ ring. J. Bacteriol. 175:1118-1125); the stfz gene (Dewar, S. J., and W. D. Donachie. 1993. Antisense transcription of the ftsZ-ftsA gene junction inhibits cell division inEscherichia coli.J. Bacteriol. 175:7097-7101); the tolC gene (Hiraga, S., et al. 1989. Chromosome partitioning inEscherichia coli:novel mutants producing anucleate cells. J. Bacteriol. 171:1496-1505; Hiraga, S., et al. 1991. Mutants defective in chromosome partitioning inE. coli.Res. Microbiol. 142:189-194); and the zipA gene (Hale, C. A., and P. A. de Boer. 1997. Direct binding of FtsZ to ZipA, an essential component of the septal ring structure that mediates cell division inE. coli.Cell. 88:175-185).
• The guanosine 5′-diphosphate 3′ diphosphate (ppGpp) or guanosine 5′-triphosphate 3′ diphosphate (pppGpp) nucleotides, collectively (p)ppGpp, found in[0299]E. colior in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Vinella, D., et al. 1993. Penicillin-binding protein 2 inactivation inEscherichia coliresults in cell division inhibition, which is relieved by FtsZ overexpression. J. Bacteriol. 175:6704-6710; Navarro, F., et al. Analysis of the effect of ppGpp on the ftsQAZ operon inEscherichia coli.Mol. Microbiol. 29:815-823). The levels, or rate of production of (p)ppGpp may be increased or decreased. By way of non-limiting example, increased (p)ppGpp production results from induction of the stringent response. The stringent response inE. coliis a physiological response elicited by a failure of the capacity for tRNA aminoacylation to keep up with the demands of protein synthesis. This response can be provoked either by limiting the availability of amino acids or by limiting the ability to aminoacylate tRNA even in the presence of abundant cognate amino acids. Many features of the stringent response behave as if they are mediated by accumulation of (p)ppGpp. The accumulation of (p)ppGpp can also be provoked by nutritional or other stress conditions in addition to a deficiency of aminoacyl-tRNA. See Cashel et al., “The Stringent Response,” Chapter 92 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^ndEd., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996,Volume 1, pages 1458-1496, and references cited therein.
• By way of non-limiting example, factors that may provoke the stringent response include the lyt gene or gene product (Harkness, R. E., et al. 1992. Genetic mapping of the lyta and lytB loci of[0300]Escherichia coli,which are involved in penicillin tolerance and control of the stringent response. Can J. Microbiol. 38:975-978), the relA gene or gene product (Vinella, D., and R. D'Ari. 1994. Thermoinducible filamentation inEscherichia colidue to an altered RNA polymerase beta subunit is suppressed by high levels of ppGpp. J. Bacteriol. 176:96-972), the relB gene or gene product (Christensen, S. K., et al. 2001. RelE, a global inhibitor of translation, is activated during nutritional stress. Proc. Natl. Acad. Sci. 98:14328-14333), the reIC (rplK) gene or gene product (Yang, X., and E. E. Ishiguro. 2001. Involvement of the N Terminus of Ribosomal Protein L11 in Regulation of the RelA Protein ofEscherichia coli.J. Bacteriol. 183:6532-6537), the relX gene or gene product (St. John, A. C., and A. L. Goldberg. 1980. Effects of starvation for potassium and other inorganic ions on protein degradation and ribonucleic acid synthesis inEscherichia coli.J. Bacteriol. 143:1223-1233), the spoT gene or gene product (Vinella, D., et al. 1996. Mecillinam resistance inEscherichia coliis conferred by loss of a second activity of the AroK protein. J. Bacteriol. 178:3818-3828), the gpp gene or gene product (Keasling, J. D., et al. 1993. Guanosine pentaphosphate phosphohydrolase ofEscherichia coliis a long-chain exopolyphosphatase. Proc. Natl. Acad. Sci. 90:7029-7033), the ndk gene or gene product (Kim, H. Y., et al. 1998. Alginate, inorganic polyphosphate, GTP and ppGpp synthesis co-regulated inPseudomonas aeruginosa:implications for stationary phase survival and synthesis of RNA/DNA precursors. Mol. Microbiol. 27:717-725), the rpoB gene or gene product (Vinella, D., and R. D'Ari. 1994. Thermoinducible filamentation inEscherichia colidue to an altered RNA polymerase beta subunit is suppressed by high levels of ppGpp. J. Bacteriol. 176:96-972), the rpoC gene or gene product (Bartlett, M. S., et al. 1998. RNA polymerase mutants that destabilize RNA polymerase-promoter complexes alter NTP-sensing by rrn P1 promoters. J. Mol. Biol. 279:331-345), the rpoD gene or gene product (Hernandez, V. J., and M. Cashel. 1995. Changes in conserved region 3 ofEscherichia colisigma 70 mediate ppGpp-dependent functions in vivo. 252:536-549), glnF gene or gene product (Powell, B. S., and D. L. Court. 1998. Control of ftsZ expression, cell division, and glutamine metabolism in Luria-Bertani medium by the alarmone ppGpp inEscherichia coli.J. Bacteriol. 180:1053-1062), or glnD gene or gene product (Powell, B. S., and D. L. Court. 1998. Control of ftsZ expression, cell division, and glutamine metabolism in Luria-Bertani medium by the alarmone ppGpp inEscherichia coli.J. Bacteriol. 180:1053-1062). These genes or gene products, and/or expression thereof, may be manipulated to create minicells.
• II.A.3.[0301]Bacillus subtilisGenes
• Exemplary genes and gene products from[0302]B. subtilis,the expression and/or sequence of which can be manipulated so as to stimulate minicell production inB. subtilisor any other organism, as can homologs thereof from any species, include without limitation, the divi (divD)gene (Van Alstyne, D., and M. I. Simon. 1971. Division mutants ofBacillus subtilis:isolation of PBS1 transduction of division-specific markers. J. Bacteriol. 108:1366-1379); the divIB (dds, ftsQ) gene (Harry, E. J., et al. 1993. Characterization of mutations in divIB ofBacillus subtilisand cellular localization of the DivIB protein. Mol. Microbiol. 7:611-621; Harry E. J., et al. 1994. Expression of divIB ofBacillus subtilisduring vegetative growth. J. Bacteriol. 176:1172-1179); the divIC gene product fromB. subtilisor homologues of this gene or gene product found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Levin, P. A., and R. Losick. 1994. Characterization of a cell division gene fromBacillus subtilisthat is required for vegetative and sporulation septum formation. J. Bacteriol. 176:1451-1459; Katis, V. L. , et al. 1997. TheBacillus subtilisdivision protein DivIC is a highly abundant membrane-bound protein that localizes to the division site; the divII (divC) gene (Van Alstyne, D., and M. I. Simon. 1971. Division mutations ofBacillus subtilis:isolation and PBS1 transduction of division-specific markers. J. Bacteriol. 108:1366-1379); the divIVA (divD) gene (Cha, J.-H., and G. C. Stewart. 1997. The divIVA minicell locus ofBacillus subtilis.J. Bacteriol. 179:1671-1683); the divIVC (divA) gene (Van Alstyne, D., and M. I. Simon. 1971. Division mutations ofBacillus subtilis:isolation and PBS1 transduction of division-specific markers. J. Bacteriol. 108:1366-1379); the divV (divB) gene (Van Alstyne, D., and M. I. Simon. 1971. Division mutations ofBacillus subtilis:isolation and PBS1 transduction of division-specific markers. J. Bacteriol. 108:1366-1379); the erzA (ytwP) gene (Levin, P. A., et al. 1999. Identification and regulation of a negative regulator of FtsZ ring formation inBacillus subtilis.Proc. Natl. Acad. Sci. 96:9642-9647); the ftsA (spoIIN) gene (Feucht, A., et al. 2001. Cytological and biochemical characterization of the FtsA cell division protein ofBacillus subtilis.Mol. Microbiol. 40:115-125); the ftsE gene (Yoshida, K., et al. 1994. Cloning and nucleotide sequencing of a 15 kb region of theBacillus subtilisgenome containing the iol operon. Microbiology. 140:2289-2298); the ftsH gene (Deuerling. E., et al. 1995. The ftsH gene ofBacillus subtilisis transiently induced after osmotic and temperature upshift. J. Bacteriol. 177:4105-4112; Wehrl, W., et al. 2000. The FtsH protein accumulates at the septum ofBacillus subtilisduring cell division and sporulation. J. Bacteriol. 182:3870-3873); the ftsK gene (Sciochetti, S. A., et al. 2001. Identification and characterization of the dif Site fromBacillus subtilis.J. Bacteriol. 183:1058-1068); the ftsL (yIID)gene (Daniel, R. A., et al. 1998. Characterization of the essential cell division gene ftsL (yIID) ofBacillus subtilisand its role in the assembly of the division apparatus. Mol. Microbiol. 29:593-604); the ftsW gene (Ikeda, M., et al. 1989. Structural similarity amongEscherichia coliFtsW and RodA proteins andBacillus subtilisSpoVE protein, which function in cell division, cell elongation, and spore formation, respectively. J. Bacteriol. 171:6375-6378); the ftsX gene (Reizer, J., et al. 1998. A novel protein kinase that controls carbon catabolite repression in bacteria. Mol. Microbiol. 27:1157-1169); the ftsZ gene (Beall, B., and J. Lutkenhaus). FtsZ inBacillus subtilisis required for vegetative septation and for asymmetric septation during sporulation. Genes and Dev. 5:44745); the gcaD gene (Hove-Jensen, B. 1992. Identification of tms-26 as an allele of the gcaD gene, which encodes N-acetylglucosamine 1-phosphate uridyltransferase inBacillus subtilis.J. Bacteriol. 174:6852-6856); the gid (ylyC) gene (Kunst, F., et al. 1997. The complete genome sequence of the gram-positive bacteriumBacillus subtilis.Nature. 390:237-238); the gidA gene (Ogasawara, N., and H. Yoshikawa. 1992. Genes and their organization in the replication origin region of the bacterial chromosome. Mol. Microbiol. 6:629-634; Nakayashiki, T., and H. Inokuchi. 1998. Novel temperature-sensitive mutants ofEscherichia colithat are unable to grow in the absence of wild-type tRNA6Leu. J. Bacteriol. 180:2931-2935); the gidB gene (Ogasawara, N., and H. Yoshikawa. 1992. Genes and their organization in the replication origin region of the bacterial chromosome. Mol. Microbiol. 6:629-634; Nakayashiki, T., and H. Inokuchi. 1998. Novel temperature-sensitive mutants ofEscherichia colithat are unable to grow in the absence of wild-type tRNA6Leu. J. Bacteriol. 180:2931-2935); the lytC (cwlB) gene (Blackman, S. A., et al. 1998. The role of autolysins during vegetative growth ofBacillus subtilis168. Microbiology. 144:73-82); the lytD (cwlG) gene (Blackman, S. A., et al. 1998. The role of autolysins during vegetative growth ofBacillus subtilis168. Microbiology. 144:73-82); the lytE (cwlF) gene (Ishikawa, S., et al. 1998. Regulation of a new cell wall hydrolase gene, cwlF, which affects cell separation inBacillus subtilis.J. Bacteriol. 180:23549-2555); the lytF (cwlE, yhdD) gene (Ohnishi, R., et al. 1999. Peptidoglycan hydrolase lytF plays a role in cell separation with CwlF during vegetative growth ofBacillus subtilis.J. Bacteriol. 181:3178-1384); the maf gene (Butler, Y. X., et al. 1993. Amplification of theBacillus subtilismaf gene results in arrested septum formation. J. Bacteriol. 175:3139-3145); the minC gene (Varley, A. W., and G. C. Stewart. 1992. The divIVB region of theBacillus subtilischromosome encodes homologs ofEscherichia coliseptum placement (minCD) and cell shape (nreBCD) determinants. J. Bacteriol. 174:6729-6742; Barak, I., et al. 1998. MinCD proteins control the septation process during sporulation ofBacillus subtilis.J. Bacteriol. 180:5327-5333); the mind gene (Varley, A. W., and G. C. Stewart. 1992. The divIVB region of theBacillus subtilischromosome encodes homologs ofEscherichia coliseptum placement (minCD) and cell shape (mreBCD) determinants. J. Bacteriol. 174:6729-6742; Barak, I., et al. 1998. MinCD proteins control the septation process during sporulation ofBacillus subtilis.J. Bacteriol. 180:5327-5333); the pbpB gene (Daniel, R. A., and J. Errington. 2000. Intrinsic instability of the essential cell division protein FtsL ofBacillus subtilisand a role for DivIB protein FtsL turnover. Mol. Microbiol. 35:278-289); the ponA gene (Pederson, L. B., et al. Septal localization of penicillin-bindingprotein 1 inBacillus subtilis.J. Bacteriol. 181:3201-3211); the prfA gene (Popham, D. L., and P. Setlow. 1995. Cloning, nucleotide sequence, and mutagenesis of theBacillus subtilisponA operon, which codes for penicillin-binding protein (PBP) 1 and a PBP-related factor. J. Bacteriol. 177:326-335); the rodB gene (Burdett, I. D. 1979. Electron microscope study of the rod-to-coccus shape change in a temperature-sensitive rod-mutant ofBacillus subtilis.J. Bacteriol. 137:1395-1405; Burdett, I. D. 1980. Quantitative studies of rod—coccus morphogenesis in a temperature-sensitive rod-mutant ofBacillus subtilis.J. Gen. Microbil. 121:93-103); the secA gene (Sadaie, Y., et al. 1991. Sequencing reveals similarity of the wild-type div+gene ofBacillus subtilisto theEscherichia colisecA gene. Gene. 98:101-105); the smc gene (Britton, R. A., et al. 1998. Characterization of a prokaryotic SMC protein involved in chromosome partitioning. Genes Dev. 12:1254-1259; Moriya, S., et al. 1998. ABacillus subtilisgene-encoding protein homologous to eukaryotic SMC motor protein is necessary for chromosome partition. Mol. Microbiol. 29:179-187; Hirano, M., and T. Hirano. 1998. ATP-dependent aggregation of single-stranded DNA by a bacterial SMC homodimer. EMBO J. 17:7139-7148); the spoIIE gene (Feucht, a., et al. 1996. Bifunctional protein required for asymmetric cell division and cell-specific transcription inBacillus subtilis.Genes Dev. 10:794-803; Khvorova, A., et al. 1998. The spoIIE locus is involved in the Spo0A-dependent switch in the localization of FtsZ rings inBacillus subtilis.J. Bacteriol. 180:1256-1260; Lucet, I., et al. 2000. Direct interaction between the cell division protein FtsZ and the cell differentiation protein SpoIIE. EMBO J. 19:1467-1475); the spo0A gene (Ireton, K., et al. 1994. spoOJ is required for normal chromosome segregation as well as the initiation of sporulation inBacillus subtilis.J. Bacteriol. 176:5320-5329); the spoIVF gene (Lee, S., and C. W. Price. 1993. The minCD locus ofBacillus subtilislacks the minE determinant that provides topological specificity to cell division. Mol. Microbiol. 7:601-610); the spo0J gene (Lin, D. C., et el. 1997. Bipolar localization of a chromosome partition protein inBacillus subtilis.Proc. Natl. Acad. Sci. 94:4721-4726; Yamaichi, Y., and H. Niki. 2000. Active segregation by theBacillus subtilispartitioning system inEscherichia coli.Proc. Natl. Acad. Sci. 97:14656-14661); the smc gene (Moriya, S., et al. 1998. ABacillus subtilisgene-encoding protein homologous to eukaryotic SMC motor protein is necessary for chromosome partition. Mol. Microbiol. 29:179-187);
• the ripX gene (ciochetti, S. A. et al. 1999. The ripX locus of[0303]Bacillus subtilisencodes a site-specific recombinase involved in proper chromosome partitioning. J. Bacteriol. 181:6053-6062); and the spoIIIE gene (Wu, L. J., and J. Errington. 1994.Bacillus subtilisspoIIIE protein required for DNA segregation during asymmetric cell division. Science. 264:572-575); the gene corresponding to theB. subtilismutant alleal ts-31 (Errington, J., and A. D. Richard. Cell division during growth and sporulation. In A. L. Sonenshein, J. A. Hoch., and R. Losick (eds.).Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); the gene corresponding to theB. subtilismutant alleal ts-526 (Id.); the yacA gene (Kunst, F., et al. 1997. The complete genome sequence of the gram-positive bacteriumBacillus subtilis.Nature. 390:237-238); the yfhF gene (Kunst, F., et al. 1997. The complete genome sequence of the gram-positive bacteriumBacillus subtilis.Nature. 390:237-238); the yfhK gene (Kunst, F., et al. 1997. The complete genome sequence of the gram-positive bacteriumBacillus subtilis.Nature. 390:237-238); the yjoB gene (Kunst, F., et al. 1997. The complete genome sequence of the gram-positive bacteriumBacillus subtilis.Nature. 390:237-238); and the ywbG gene (Smith, T. J., et al. 2000. Autolysins ofBacillus subtilis:multiple enzymes with multiple functions. Microbiology. 146:249-262).
• II.A.3.[0304]Saccharomyes cervisiaeGenes
• Exemplary genes and gene products from[0305]S. cerevisiaethe expression and/or sequence of which can be manipulated so as to stimulate minicell production in any organism, as can homologs thereof from any species, include without limitation, the trf gene product family (TRF1, TRF2, TRF3, TRF4, and TRF5) fromSaccharomyces cerevisiae(Sadoff, B. U., et al. 1995. Isolation of mutants ofSaccharomyces cerevisiaerequiring DNA topoisomerase I. Genetics. 141:465-479; Castano, I. B., et al. 1996. A novel family of TRF (DNA topoisomerase I-related function) genes required for proper nuclear segregation. Nucleic Acids Res. 2404-2410); the 1BD1 gene product fromSaccharomyces cerevisiae(Lee, J., et al. 1999. Ibd1p, a possible spindle pole body associated protein, regulates nuclear division and bud separation inSaccharomyces cerevisiae.Biochim. Biophys. Acta. 1449:239-253); the plo1 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1541-1534); the cdc7 locus product(s) fromSaccharomyces cerevisiaeor homologues of this found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Biggins, s. et al. 2001. Genes involved in sister chromatid separation and segregation in the budding yeastSaccharomyces cerevisiae.Genetics. 159:453-470); the cdc15 locus product(s) fromSaccharomyces cerevisiaeor homologues of this found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Mah, A. S., et al. 2001. Protein kinase Cdc15 activates the Dbf2-Mob1 kinase complex. Proc. Natl. Acad. Sci. 98:7325-7330); the cdc11 locus product(s) fromSaccharomyces cerevisiaeor homologues of this found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Fares, H., et al. 1996. Identification of a developmentally regulated septin and involvement of the septins in spore formation inSaccharomyces cerevisiae.J. Cell Biol. 132:399-411); the spgl locus product(s) fromSaccharomyces cerevisiaeor homologues of this found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the sid2 locus product(s) fromSaccharomyces cerevisiaeor homologues of this found in other members of the Eubacteria, Eucarya or Archaea may be employed to produce minicells (Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the cdc8 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the rhol gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the mpd1 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the mpd2 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the smy2 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the cdc16 gene product fromSaccharomyces cerevisiae(Heichman, K. A., and J. M. Roberts. 1996. The yeast CDC16 and CDC27 genes restrict DNA replication to once per cell cycle. Cell. 85:39-48); the dma1 gene product fromSaccharomyces cerevisiae(Murone, M., and V. Simanis. 1996. The fission yeast dma1 gene is a component of the spindle assembly checkpoint, required to prevent septum formation and premature exit from mitosis if spindle function is compromised. EMBO J. 15:6605-6616); the plo1 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the byr3 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the byr4 gene product fromSaccharomyces cerevisiae(Cullen, C. F., et al. 2000. A new genetic method for isolating functionally interacting genes: high plo1(+)-dependent mutants and their suppressors define genes in mitotic and septation pathways in fission yeast. Genetics. 155:1521-1534); the pds1 gene product fromSaccharomyces cerevisiae(Yamamoto, A., et al. 1996. Pds1p, an inhibitor of anaphase in budding yeast, plays a critical role in the APC and checkpoint pathway(s). J. Cell Biol. 133:99-110); the esp1 gene product fromSaccharomyces cerevisiae(Rao, H., et al. 2001. Degradation of a cohesin subunit by the N-end rule pathway is essential for chromosome stability. Nature. 410:955-999); the ycs4 gene product fromSaccharomyces cerevisiae(Biggins, S., et al. 2001. Genes involved in sister chromatid separation and segregation in the budding yeastSaccharomyces cerevisiae.Genetics. 159:453-470); the cse4 gene product fromSaccharomyces cerevisiae(Stoler, S. et al. 1995. A mutation in CSE4, an essential gene encoding a novel chromatin-associated protein in yeast, causes chromosome nondisjunction and cell cycle arrest at mitosis. Genes Dev. 9:573-586); the ipl1 gene product fromSaccharomyces cerevisiae(Biggins, S., and A. W. Murray. 2001. The budding yeast protein kinase Ipl1/Aurora allows the absence of tension to activate the spindle checkpoint. Genes Dev. 15:3118-3129); the smt3 gene product fromSaccharomyces cerevisiae(Takahashi, Y., et al. 1999. Smt3, a SUMO-1 homolog, is conjugated to Cdc3, a component of septin rings at the mother-bud neck in budding yeast. Biochem. Biophys. Res. Commun. 259:582-587); the prp16 gene product fromSaccharomyces cerevisiae(Hotz, H. R., and B. Schwer. 1998. Mutational analysis of the yeast DEAH-box splicing factor Prp16. Genetics. 149:807-815); the prp19 gene product fromSaccharomyces cerevisiae(Chen, C. H., et al. 2001. Identification and characterization of two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p. J. Biol. Chem. 276:488-494); the wss1 gene product fromSaccharomyces cerevisiae(Biggins, S., et al. 2001. Genes involved in sister chromatid separation and segregation in the budding yeastSaccharomyces cerevisiae.Genetics. 159:453-470); the histone H4 gene product fromSaccharomyces cerevisiae(Smith, M. M., et al. 1996. A novel histone H4 mutant defective in nuclear division and mitotic chromosome transmission. Mol. Cell Biol. 16:1017-1026); the histone H3 gene product fromSaccharomyces cerevisiae(Smith, M. M., et al. 1996. A novel histone H4 mutant defective in nuclear division and mitotic chromosome transmission. Mol. Cell Biol. 16:1017-1026); the cse4 gene product fromSaccharomyces cerevisiae(Stoler, S., et al. 1995. A mutation in CSE4, an essential gene encoding a novel chromatin-associated protein in yeast, causes chromosome nondisjunction and cell cycle arrest at mitosis. Genes Dev. 10 9:573-586); the spt4 gene product fromSaccharomyces cerevisiae(Basrai, M. A., et al. 1996. Faithful chromosome transmission requires Spt4p, a putative regulator of chromatin structure inSaccharomyces cerevisiae.Mol. Cell Biol. 16:2838-2847); the spt5 gene product fromSaccharomyces cerevisiae(Yamaguchi, Y., et al. 2001. SPT genes: key players in the regulation of transcription, chromatin structure and other cellular processes. J. Biochem. (Tokyo). 129:185-191); the spt6 gene product fromSaccharomyces cerevisiae(Clark-Adams, C. D., and F. Winston. 1987. The SPT6 gene is essential for growth and is required for delta-mediated transcription inSaccharomyces cerevisiae.Mol. Cell Biol. 7:679-686); the ndc10 gene product fromSaccharomyces cerevisiae(Chiang, P. W., et al. 1998. Isolation of murine SPT5 homologue: completion of the isolation and characterization of human and murine homologues of yeast chromatin structural protein complex SPT4, SPT5, and SPT6. Genomics. 47:426-428); the ctf13 gene product fromSaccharomyces cerevisiae(Doheny et al., Identification of essential components of theS. cerevisiaekinetochore, Cell 73:761-774, 1993); the spo1 gene product fromSaccharomyces cerevisiae(Tavormina et al. 1997. Differential requirements for DNA replication in the activation of mitotic checkpoints inSaccharomyces cerevisiae.Mol. Cell Biol. 17:3315-3322); the cwp1 gene product fromSaccharomyces cerevisiae(Tevzadze, G. G., et al. 2000. Spo1, a phospholipase B homolog, is required for spindle pole body duplication during meiosis inSaccharomyces cerevisiae.Chromosoma. 109:72-85); the dhp1 gene product fromSchizosaccharomyces pombe(Shobuike, T., et al. 2001. The dhp1(+) gene, encoding a putative nuclear 5′→3′ xoribonuclease, is required for proper chromosome segregation in fission yeast. Nucleic Acids Res. 29:1326-1333); the rat1 gene product fromSaccharomyces cerevisiae(Shobuike, T., et al. 2001. The dhp1(+) gene, encoding a putative nuclear 5′→3′ exoribonuclease, is required for proper chromosome segregation in fission yeast. Nucleic Acids Res. 29:1326-1333); the hsk1 gene product fromSaccharomyces cerevisiae(Masai, H., et al. 1995. hsk1+, aSchizosaccharomyces pombegene related toSaccharomyces cerevisiaeCDC7, is required for chromosomal replication. EMBO J. 14:3094-3104); the dfp1 gene product fromSaccharomyces cerevisiae(Takeda, T., et al. 1999. A fission yeast gene, him1(+)/dfp1(+), encoding a regulatory subunit for Hsk1 kinase, plays essential roles in S-phase initiation as well as in S-phase checkpoint control and recovery from DNA damage. Mol. Cell Biol. 19:5535-5547); the dbf4 gene product fromSaccharomyces cerevisiae(Weinreich, M., and B. Stillman. 1999. Cdc7p-Dbf4p kinase binds to chromatin during S phase and is regulated by both the APC and the RAD53 checkpoint pathway. EMBO J. 18:5334-5346); the rad53 gene product fromSaccharomyces cerevisiae(Sun, Z., et al. Spk1/Rad53 is regulated by Mec1-dependent protein phosphorylation in DNA replication and damage checkpoint pathways. Genes Dev. 10:395-406); the ibd1 gene product fromSaccharomyces cerevisiae(Lee, J., et al. 1999. Ibd1p, a possible spindle pole body associated protein, regulates nuclear division and bud separation inSaccharomyces cerevisiae.Biochim. Biophys. Acta. 1449:239-253); and the hrp1 gene product fromSaccharomyces cerevisiae(Henry, M., et al. 1996. Potential RNA binding proteins inSaccharomyces cerevisiaeidentified as suppressors of temperature-sensitive mutations in NPL3. Genetics. 142:103-115).
• II.B. Gene Expression in Minicells[0306]
• II.B.1. In General[0307]
• In some aspects of the invention, it may be desirable to alter the expression of a gene and the production of the corresponding gene product. As is known in the art, and is used herein, a “gene product” may be a protein (polypeptide) or nucleic acid. Gene products that are proteins include without limitation enzymes, receptors, transcription factors, termination factors, expression factors, DNA-binding proteins, proteins that effect nucleic acid structure, or subunits of any of the preceding. Gene products that are nucleic acids include, but are not limited to, ribosomal RNAs (rRNAs), transfer RNAs (tRNAs), antisense RNAs, nucleases (including but not limited to catalytic RNAs, ribonucleases, and the like).[0308]
• Depending on the function of a gene product, and on the type of application of the invention, it may be desirable to increase protein production, decrease protein production, increase protein nucleic acid production and/or increase nucleic acid production. Provided herein are non-limiting examples of genes and gene products that may be manipulated, individually or in combination, in order to modulate the expression of gene products to be included into minicells or parent strains from which minicells are derived. The expression elements so modulated may be chromosomal and/or episomal, and may be expressed constitutively or in a regulated fashion, i.e., repressible and/or inducible. Furthermore, gene products under the regulation may be either monocistronic or polycistronic with other genes or with themselves.[0309]
• II.B.2. Protein Production[0310]
• By way of non-limiting example, increased protein production may occur through increased gene dosage (increased copy number of a given gene under the control of the native or artificial promotor where this gene may be on a plasmid or in more than one copy on the chromosome), modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, cloning on a plasmid under the control of the native or artificial promotor, and increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the gene or gene product[0311]
• By way of non-limiting example, decreased protein production may occur through modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, through cloning on a plasmid under the control of the native regulatory region containing mutations or an artificial promotor, either or both of which resulting in decreased protein production, and through increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the gene or gene product.[0312]
• As used herein with regards to proteins, “intramolecular activity” refers to the enzymatic function or structure-dependent function. By way of non-limiting example, alteration of intramolecular activity may be accomplished by mutation of the gene, in vivo or in vitro chemical modification of the protein, inhibitor molecules against the function of the protein, e.g. competitive, non-competitive, or uncompetitive enzymatic inhibitors, inhibitors that prevent protein-protein, protein-nucleic acid, or protein-lipid interactions, e.g. expression or introduction of dominant-negative or dominant-positive protein or other protein fragment(s), carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s) that may act directly or allosterically upon the protein, and/or modification of protein, carbohydrate, fatty acid, lipid, or nucleic acid moieties that modify the gene or gene product to create the functional protein.[0313]
• As used herein with regards to proteins, “intermolecular function” refers to the effects resulting from an intermolecular interaction between the protein or nucleic acid and another protein, carbohydrate, fatty acid, lipid, nucleic acid, or other molecule(s) in or on the cell or the action of a product or products resulting from such an interaction. By way of non-limiting example, intermolecular or intramolecular function may be the act or result of intermolecular phosphorylation, biotinylation, methylation, acylation, glycosylation, and/or other signaling event; this function may be the result of a protein-protein, protein-nucleic acid, or protein-lipid complex, and/or carrier function, e.g. the capacity to bind, either covalently or non-covalently small organic or inorganic molecules, protein(s), carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s); this function may be to interact with the membrane to recruit other molecules to this compartment of the cell; this function may be to regulate the transcription and/or translation of the gene, other protein, or nucleic acid; and this function may be to stimulate the function of another process that is not yet described or understood.[0314]
• II.B.3. Nucleic Acid Production[0315]
• By way of non-limiting example, increased nucleic acid production may occur through increased gene dosage (increased copy number of a given gene under the control of the native or artificial promotor where this gene may be on a plasmid or in more than one copy on the chromosome), modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, cloning on a plasmid under the control of the native or artificial promotor, and increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the gene or gene product.[0316]
• By way of non-limiting example, decreased nucleic acid production may occur through modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, through cloning on a plasmid under the control of the native regulatory region containing mutations or an artificial promotor, either or both of which resulting in decreased protein production, and through increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the gene or gene product.[0317]
• As used herein with regards to nucleic acids, “intramolecular activity” refers to a structure-dependent function. By way of non-limiting example, alteration of intramolecular activity may be accomplished by mutation of the gene, in vivo or in vitro chemical modification of the nucleic acid, inhibitor molecules against the function of the nucleic acid, e.g. competitive, non-competitive, or uncompetitive enzymatic inhibitors, inhibitors that prevent protein-nucleic acid interactions, e.g. expression or introduction of dominant-negative or dominant-positive protein or other nucleic acid fragment(s), or other carbohydrate(s), fatty acid(s), and lipid(s) that may act directly or allosterically upon the nucleic acid or nucleic acid-protein complex, and/or modification of nucleic acid moieties that modify the gene or gene product to create the functional nucleic acid.[0318]
• As used herein with regards to nucleic acids, “intermolecular function” refers to the effects resulting from an intermolecular interaction between the nucleic acid and another nucleic acid, protein, carbohydrate, fatty acid, lipid, or other molecule(s) in or on the cell or the action of a product or products resulting from such an interaction. By way of non-limiting example, intermolecular function may be the act or result of intermolecular or intramolecular phosphorylation, biotinylation, methylation, acylation, glycosylation, and/or other signaling event; this function may be the result of a protein-nucleic acid, and/or carrier function, e.g. the capacity to bind, either covalently or non-covalently small organic or inorganic molecules, protein(s), carbohydrate(s), fatty acid(s), lipid(s), and other nucleic acid(s); this function may be to interact with the membrane to recruit other molecules to this compartment of the cell; this function may be to regulate the transcription and/or translation of the gene, other nucleic acid, or protein; and this function may be to stimulate the function of another process that is not yet described or understood.[0319]
• II.C. Genes and Gene Products for Regulation of Expression[0320]
• As is known in the art, a variety of genes, gene products and expression elements may be manipulated, individually or in combination, in order to modulate the expression of genes and/or production gene products. These include, by way of non-limiting example, RNA polymerases, ribosomes (ribosomal proteins and ribosomal RNAs), transfer RNAs (tRNAs), amino transferases, regulatory elements and promoter regions, transportation of inducible and inhibitory compounds, catabolite repression, general deletions and modifications, cytoplasmic redox state, transcriptional terminators, mechanisms for ribosomal targeting, proteases, chaperones, export apparatus and membrane targeting, and mechanisms for increasing stability and solubility. Each of these is discussed in more detail in the following sections.II.C.1. RNA Polymerases[0321]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include modification of an endogenous and/or introduction of an exogenous RNA polymerase. A rpo gene, or any other gene that encodes a RNA polymerase subunit product from[0322]E. coli,or homologs of this gene or its gene product found in other prokaryotes, eukaryotes, archaebacteria or organelles (mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells.
• The production or activity of a desired gene product may be increased by increasing the level and/or activity of an RNA polymerase that transcribes the gene product's cognate gene. The production or activity of a desired protein gene product may be increased by decreasing the level and/or activity of an RNA polymerase that transcribes a gene product that inhibits the production or function of the desired gene product.[0323]
• As one example, manipulation of the rpoA (phs, sez) gene or gene product from[0324]E. coli,or homologs of this gene or gene product found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and/or organelles (e.g., mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells. In addition to rpoA,E. coli.genes that encode RNA polymerase subunits include rpoB (ftsR, groN, nitB, rif, ron, stl, stv, tabD, sdgB, mbrD), rpoC (tabD), rpoD (alt), rpoE, rpoH (fam, hin, htpR), rpoN (glnF, ntrA), rpoS (abrD, dpeB, katF, nur), and rpoZ (spoS). See Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein; and Sanderson et al., “Linkage Map ofSalmonella typhimurium,Edition VIII” Chapter 110 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1903-1999, and references cited therein.
• Production of a desired gene product may be preferentially or selectively enhanced by the introduction of an exogenous RNA polymerase that specifically recognizes expression sequences that are operably linked to the corresponding gene. By way of non-limiting example, the use of a T7 RNA polymerase to selectively express genes present on expression elements that segregate into minicells is described herein.[0325]
• II.C.2. Ribosomes[0326]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include modification of endogenous, and/or addition of exogenous, ribosomes or ribosomal subunits. The techniques may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells.[0327]
• As is known in the art, a ribosome includes both proteins (polypeptides) and RNA (rRNA). Thus, in the case of a gene that encodes a component of a ribosome, the gene product may be a protein or an RNA. For a review, see Noller et al., “Ribosomes,” Chapter 13 in:[0328]Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996,Volume 1, pages 167-186, and references cited therein. For the sake of convenience, both ribosomal proteins and rRNAs are encompassed by the term “ribosomal subunits.”
• The production or activity of a desired protein gene product may be increased by increasing the level and/or activity of a ribosomal subunit that causes or enhances the translation of the desired protein. The production or activity of a desired protein gene product may be increased by decreasing the level and/or activity of a ribosomal subunit that causes or enhances translation of a protein that has a negative impact on the production or activity of the desired protein.[0329]
• Exemplary ribosomal genes and gene products that may be manipulated include without limitation the[0330]E. coligenes rimB, rimC, rimD, rimE, rimF (res), rimG, rimH, rimI, rimJ (tcp), rimK, rimL; rplA, rplB, rplC, rplD, rplE, rplF, rplI, rplJ, rplK, rplL, rplM, rplN, rplO, rplP, rplQ, rplR, rplS, rplT, rplU, rplV, rplW, rplX, rplY; rpsA, rpsB, rpsC, rpsE (eps, spc, spcA), rpsF (sdgH), rpsG, rpsH, rpsI, rpsJ (nusE), rpsK, rpsL (strA), rpsM, rpsN, rpsO, rpsP, rpsQ, rpsR, rpsS, rpsT, rpsU, rpsV; rrfA, rrfB, rrfC, rrfD, rrfE, rrfF (rrfdbeta, rrvD), rrfG, rrfH; rrlA, rrlB, rrlC, rrlD, rrlE, rrlG, rrlH; rrnA, rrnB (csqE, rrnBl), rrnC (cqsB), rrnD (cqsD), rrnE (rrnD1), rrnG, rrnH; rrsA, rrsB, rrsC, rrsD, rrsE, rrsG, rrsH, and their cognate gene products.
• Homologs of ribosomal genes or gene products found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and organelles (including but not limited to mitochondria, chloroplasts, plastids, and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or segregated minicells. See, for example, Barkan, A. and M. Goldschmidt-Clermont, Participation of nuclear genes in chloroplast gene expression, (2000)[0331]Biochimie82:559-572; Willhoeft, U., H. Bu, and E. Tannich, Analysis of cDNA Expressed sequence tags fromEntamoeba histolytica:Identification of two highly abundant polyadenylated transcripts with no overt open reading frames, (March 1999)Protist150:61-70; Emelyanov, V., Evolutionary relationship ofRickettsiaeand mitochondria (Feb. 2001)FEBS Letters501:11-18; and Gray, M., G. Burger and B. Lang, Mitochondrial Evolution (Mar. 1999)Science283:1476-1481. Ribosomal RNA sequences from a multitude of organisms and organelles are available through the Ribosomal Database Project (Maidak et al., A new version of the RDP (Ribosomal Database Project) (1999)Nucleic Acids Research27:171-173). An index of ribosomal proteins classified by families on the basis of sequence similarities is available on-line at http://www.expasy.ch/cgi-bin/lists?ribosomp.txt; see also (Ramakrishnan et al., Ribosomal protein structures: insights into the architecture, machinery and evolution of the ribosome,TIBS23:208-212, 1998.
• II.C.3. Transfer RNAs (tRNAs)[0332]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of endogenous and/or exogenous transfer RNAs (tRNAs). Manipulation of the tRNA genes or gene products from[0333]E. coli,or homologs of tRNA genes or gene products found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and organelles (including but not limited to mitochondria, chloroplasts, plastids, and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells.
• Exemplary[0334]E. colitRNA genes include, but are not limited to, the alaT (talA) gene, the alaU (talD) gene, the alaV gene, the alaW (alaW) gene, the alaX (alaW) gene, the argQ (alaV) gene, the argU (dnaY, pin) gene, the alaU (talD) gene, the argV(argV2) gene, the argW gene, the argX gene, the argY (argV) gene, the argZ (argV) gene, the asnT gene, the asnU gene, the asnV gene, the aspT gene, the aspU gene, the cysT gene, the glnU (supB) gene, the glnV (supE) gene, the glnW (supB) gene, the gltT (tgtB) gene, the gltU (tgtC) gene, the gltV (tgtE) gene, the gltW gene, the glyT (sumA) gene, the glyU (sufD, sumA, sumB, supT) gene, the glyV (ins, mutA) gene, the glyW (ins, mutC) gene, the glyX gene, the glyY gene, the hisR (hisT) gene, the ileT gene, the ileU gene, the ileV gene, the ileX gene, the leuP (leuV) gene, the leuQ (leuV) gene, the leuQ (leuV) gene, the leuT gene, the leuU gene, the leuV (leuV) gene, the leuW (feeB) gene, the leuX (supP) gene, the leuZ gene, the lysT gene, the lysV (supN) gene, the lysW gene, the metT (metT) gene, the metU (metT) gene, the metV (metZ) gene, the metW gene, the metY gene, the pheU (pheR, pheW) gene, the pheV gene, the proK (proV) gene, the proL (proW) gene, the proM (proU) gene, the serT (divE) gene, the serU (ftsM, supD, supH) gene, the serV (supD) gene, the serW gene, the serX (serW) gene, the thrT gene, the thrU gene, the thrV gene, the thrW gene, the trpT (supU) gene, the tyrT (supC) gene, the tyrU (supM) gene, the atyrV (tyrT, tyrT) gene, the valT gene, the valU (valU) gene, the valV (val) gene, the valW (val) gene, the valX gene, and the valX gene (Komine et al., Genomic Organization and Physical Mapping of the Transfer RNA Genes inEscherichia coliK12. J. Mol. Biol. 212:579-598, 1990; Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia Coli and Salmonella Typhimurium: Cellular and Molecular Biology,2^ndEd., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein; Sanderson et al., “Linkage Map ofSalmonella typhimurium,Edition VIII” Chapter 110, Id., pages 1903-1999, and references cited therein; and Hershey, “Protein Synthesis,” Chapter 40 in:Escherichia Coli and Salmonella Typhimurium: Cellular and Molecular Biology,Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987, Volume 2, pages 613-647, and references cited therein).
• Also included in the modification of transfer RNA molecules are the transfer RNA processing enzymes. Exemplary[0335]E. coligenes encoding tRNA processing enzymes include, but are not limited to the rnd gene (Blouin R T, Zaniewski R, Deutscher M P. Ribonuclease D is not essential for the normal growth ofEscherichia colior bacteriophage T4 or for the biosynthesis of a T4 suppressor tRNA, J Biol Chem. 258:1423-1426, 1983) and the rnpAB genes (Kirsebom L A, Baer M F, Altman S., Differential effects of mutations in the protein and RNA moieties of RNase P on the efficiency of suppression by various tRNA suppressors, J Mol Biol. 204:879-888, 1988).
• Also included in the modification of transfer RNA molecules are modifications in endogenous tmRNAs and/or the introduction of exogenous tmRNAs to minicells and/or their parent cells. The tmRNA (a.k.a. 10S RNA) molecules have properties of tRNAs and mRNAs combined in a single molecule. Examples of tmRNAs are described in Zwieb et al. (Survey and Summary: Comparative Sequence Analysis of tmRNA, Nucl. Acids Res. 27:21063-2071, 1999).[0336]
• II.C.4. Aminoacyl Synthetases[0337]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of endogenous and/or exogenous aminoacyl synthetases and proteins that effect their production and/or activity. Aminoacyl synthetases are involved in “charging” a tRNA molecule, i.e., attaching a tRNA to its cognate amino acid. (Martinis et al., Aminoacyl-tRNA Synthetases: General Features and Relationships. Chapter 58 in:[0338]Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996,Volume 1, pages 887-901) and references cited therein; (Grunberg-Manago, Regulation of the Expression of Aminoacyl-tRNA Synthetases and Translation. Chapter 91 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996,Volume 1, pages 1432-1457), and references cited therein; and (Hershey, “Protein Synthesis,” Chapter 40 in:Escherichia Coli and Salmonella Typhimurium: Cellular and Molecular Biology,Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987,Volume 1, pages 613-647), and references cited therein.
• By way of non-limiting example, manipulation of the aat gene or gene product from[0339]E. coli,or homologs of this gene or gene product found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and/or organelles (e.g., mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells (Bochner, B. R., and Savageau, M. A. 1979. Inhibition of growth by imidazol(on)e propionic acid: evidence in vivo for coordination of histidine catabolism with the catabolism of other amino acids. Mol. Gen. Genet. 168(1):87-95).
• In addition to aat, other exemplary[0340]E. coligenes encoding aminoacyl synthestases include alaS (act, ala-act, lovB) (Buckel et al., Suppression of temperature-sensitive aminoacyl-tRNA synthetase mutations by ribosomal mutations: a possible mechanism. Mol. Gen. Genet. 149:51-61, 1976); argS (lovB) (Eriani et al., Isolation and characterization of the gene coding forEscherichia coliarginyl-tRNA synthetase. Nucleic Acids Res. 17:5725-36, 1989); asnS (Ics, tss) (Yamamoto et al., Identification of a temperature-sensitive asparaginyl-transfer ribonucleic acid synthetase mutant ofEscherichia coli.J. Bacteriol. 132:127-31, 1977); aspS (tls) (Eriani et al., Aspartyl-tRNA synthetase fromEscherichia coli:cloning and characterisation of the gene, homologies of its translated amino acid sequence with asparaginyl- and lys1-tRNA syntheases. Nucleic Acids Res. 18:7109-18, 1990); cysS (Eriani et al., Cysteinyl-tRNA synthetase: determination of the lastE. coliaminoacyl-tRNA synthetase primary structure. Nucleic Acids Res. 19:265-9, 1991); glnS (Yamao et al.,Escherichia coliglutaminyl-tRNA synthetase. I. Isolation and DNA sequence of the glnS gene. J. Biol. Chem. 257:11639-43, 1982); gltE (Lapointe et al., Thermosensitive mutants ofEscherichia coliK-12 altered in the catalytic Subunit and in a Regulatory factor of the glutamy-transfer ribonucleic acid synthetase. J. Bacteriol. 122:352-8, 1975); gltM (Lapointe et al., Thermosensitive mutants ofEscherichia coliK-12 altered in the catalytic Subunit and in a Regulatory factor of the glutamy-transfer ribonucleic acid synthetase. J. Bacteriol. 122:352-8, 1975); gltX (Lapointe et al., Thermosensitive mutants ofEscherichia coliK-12 altered in the catalytic Subunit and in a Regulatory factor of the glutamy-transfer ribonucleic acid synthetase. J. Bacteriol. 122:352-8, 1975); glyQ (glySa) (Webster et al., Primary structures of both subunits ofEscherichia coliglycyl-tRNA synthetase, J. Biol. Chem. 252:10637-41, 1983); glyS (act, gly, glySB) (Id.); hisS (Parker et al., Mapping hisS, the structural gene for histidyl-transfer ribonucleic acid synthetase, inEscherichia coli.J. Bacteriol. 138:264:7, 1979); ileS (Singer et al., Synthesis of the isoleucyl- and valyl-tRNA synthetases and the isoleucine-valine biosythetic enzymes in a threonine deaminase regulatory mutant ofEscherichia coliK-12. J. Mol. Biol. 175:39-55, 1984); leuS (Morgan et al., Regulation of biosythesis of aminoacyl-transfer RNA synthestases and of transfer-RNA inEscherichia coli.Arch. Biol. Med. Exp. (Santiago.) 12:415-26, 1979); lysS (herC, asaD) (Clark et al., Roles of the two lysyl-tRNA synthetases ofEscherichia coli:analysis of nucleotide sequences and mutant behavior. J. Bacteriol. 172:3237-43, 1990); lysU (Clark et al., Roles of the two lysyl-tRNA synthetases ofEscherichia coli:analysis of nucleotide sequences and mutant behavior, J. Bacteriol. 172:3237-43, 1990); metG (Dardel et al., Molecular cloning and primary structure of theEscherichia colimethionyl-tRNA synthetase gene. J. Bacteriol. 160:1115-22, 1984); pheS (phe-act) (Elseviers et al., Molecular cloning and regulation of expression of the genes for initiation factor 3 and two aminoacyl-tRNA synthetases, J. Bacteriol. 152:357-62, 1982); pheT (Comer et al., Genes for the alpha and beta subunits of the phenylalanyl-transfer ribonucleic acid synthetase ofEscherichia coli.J. Bacteriol. 127:923-33, 1976); proS (drp) (Bohman et al., A temperature-sensitive mutant in prolinyl-tRNA ligase ofEscherichia coliK-12 Mo. Gen. Genet. 177:603-5, 1980); serS (Hartlein et al., Cloning and characterization of the gene forEscherichia coliseryl-tRNA synthetase. Nucleic Acids Res. 15:1005-17, 1987); thrS (Frohler et al., Genetic analysis of mutations causing borrelidin resistance by overproduction of threonyl-transfer ribonucleic acid synthetase. J. Bacteriol. 143:1135-41, 1980); trpS (Hall et al., Cloning and characterization of the gene forEscherichia colitryptophanyl-transfer ribonucleic acid synthetase. J. Bacteriol. 148:941-9, 1981); tyrS (Buonocore et al., Properties of tyrosyl transfer ribonucleic acid synthetase from two tyrS mutants ofEscherichia coliK-12. J. Biol. Chem. 247:4843-9, 1972); and valS (Baer et al., Regulation of the biosynthesis of aminoacyl-transfer ribonucleic acid synthetases and of transfer ribonucleic acid inEscherichia coli.V. Mutants with increased levels of valyl-transfer ribonucleic acid synthetase. J. Bacteriol. 139:165-75, 1979).
• II.C.5. Regulatory Elements and Promoter Regions[0341]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of regulatory elements and promoter regions. Such manipulations may result in increased or decreased production, and/or changes in the intramolecular and intermolecular functions, of a protein in a segregated minicell or its parent cell prior to minicell formation; in the latter instance, the protein may be one that is desirably retained in segregated minicells.[0342]
• The production or activity of a desired gene product may be increased by increasing the level and/or activity of a promoter or other regulatory region that acts to stimulate or enhance the production of the desired gene product. The production or activity of a desired gene product may be increased by decreasing the level and/or activity of a promoter or other regulatory region that acts to stimulate or enhance the production of a gene product that acts to reduce or eliminate the level and/or activity of the desired gene product.[0343]
• II.C.5.a.[0344]Escherichia coli
• Regulatory elements, promoters and other expression elements and expression factors from[0345]E. coliinclude but are not limited to acrR (Ma, D., et al. 1996. The local repressor AcrR plays a modulating role in the regulation of acrAB genes ofEscherichia coliby global stress signals. Mol. Microbiol. 19:101-112); ampD (Lindquist, S., et al. 1989. Signalling proteins in enterobacterial AmpC beta-lactamase regulation. Mol. Microbiol. 3:1091-1102; Holtje, J. V., et al. 1994. The negative regulator of beta-lactamase induction AmpD is a N-acetyl-anhydromuramyl-L-alanine amidase. FEMS Microbiol. Lett. 122:159-164); appR (Diaz-Guerra, L., et al. 1989. appR gene product activates transcription of microcin C7 plasmid genes. J. Bacteriol. 171:2906-2908; Touati, E., et al. 1991. Are appR and katF the sameEscherichia coligene encoding a new sigma transcription initiation factor? Res. Microbiol. 142:29-36); appY (Atlung, T., et al. 1989. Isolation, characterization, and nucleotide sequence of appY, a regulatory gene for growth-phase-dependent gene expression inEscherichia coli.J. Bacteriol. 171:1683-1691); araC (Casadaban, M. J., et al. 1976. Regulation of the regulatory gene for the arabinose pathway, araC. J. Mol. Biol. 104:557-566); arcA (Iuchi, S., and E. C. Lin. 1988. arcA (dye), a global regulatory gene inEscherichia colimediating repression of enzymes in aerobic pathways. Proc. Natl. Acad. Sci. 85:1888-1892; Iuchi, S., et al. 1989. Differentiation of arcA, arcB, and cpxA mutant phenotypes ofEscherichia coliby sex pilus formation and enzyme regulation. J. Bacteriol. 171:2889-2893); argR (xerA, Rarg) (Kelln, R. A., and V. L. Zak. 1978. Arginine regulon control in aSalmonella typhimurium—Escherichia colihybrid merodiploid. Mol. Gen Genet. 161:333-335; Vogel, R. H., et al. 1978. Evidence for translational repression of arginine biosynthetic enzymes inEscherichia coli:altered regulation in a streptomycin-resistant mutant. Mol. Gen. Genet. 162:157-162); ascG (Hall, B. G., and L. Xu. Nucleotide sequence, function, activation, and evolution of the cryptic asc operon ofEscherichia coliK12. Mol. Biol. Evol. 9:688-706); aslB (Bennik, M. H., et al. 2000. Defining a rob regulon inEscherichia coliby using transposon mutagenesis. J. Bacteriol. 182:3794-3801); asnC (Kolling, R., and H. Lother. 1985. AsnC: an autogenously regulated activator of asparagine synthetase A transcription inEscherichia coli.J. Bacteriol. 164:310-315); atoC (Jenkins, L. S., and W. D. Nunn. 1987. Regulation of the ato operon by the atoC gene inEscherichia coli.J. Bacteriol. 169:2096-2102); baeR (Nagasawa, S., et al. 1993. Novel members of the two-component signal transduction genes inEscherichia coli.J. Biochem. (Tokyo). 114:350-357); baeS (Id.Id.); barA (Nagasawa, S., et al. 1992. A novel sensor-regulator protein that belongs to the homologous family of signal-transduction proteins involved in adaptive responses inEscherichia coli.Mol. Microbiol. 6:799-807; Ishige, K., et al. 1994. A novel device of bacterial signal transducers. EMBO J. 13:5195-5202); basS (Nagasawa, S., et al. 1993. Novel members of the two-component signal transduction genes inEscherichia coli.J. Biochem. (Tokyo). 114:350-357); betI (Lamark, T., et al. 1996. The complex bet promoters ofEscherichia coli:regulation by oxygen (ArcA), choline (BetI), and osmotic stress. J. Bacteriol. 178:1655-1662); bglG (bglC, bglS) (Schnetz, K., and B. Rak. 1988. Regulation of the bgl operon ofEscherichia coliby transcriptional antitermination. EMBO J. 7:3271-3277; Schnetz, K., and B. Rak. 1990. Beta-glucoside permease represses the bgl operon ofEscherichia coliby phosphorylation of the antiterminator protein and also interacts with glucose-specific enzyme III, the key element in catabolite control. Proc. Natl. Acad. Sci. 87:5074-5078); birA (bioR, dhbB) (Barker, D. F., and A. M. Campbell. 1981. Genetic and biochemical characterization of the birA gene and its product: evidence for a direct role of biotin holoenzyme synthetase in repression of the biotin operon inEscherichia coli.J. Mol. Biol. 146:469-492; Barker, D. F., and A. M. Campbell. 1981. The birA gene ofEscherichia coliencodes a biotin holoenzyme synthetase. J. Mol. Biol. 146:451-467; Howard, P. K., et al. 1985. Nucleotide sequence of the birA gene encoding the biotin operon repressor and biotin holoenzyme synthetase functions ofEscherichia coli.Gene. 35:321-331); btuR (Lundrigan, M. D., et al. 1987. Separate regulatory systems for the repression of metE and btuB by vitamin B12 inEscherichia coli.Mol. Gen. Genet. 206:401-407; Lundrigan, M. D., and R. J. Kadner. 1989. Altered cobalamin metabolism inEscherichia colibtuR mutants affects btuB gene regulation. J. Bacteriol. 171:154-161); cadC (Watson, N., et al. 1992. Identification of elements involved in transcriptional regulation of theEscherichia colicad operon by external pH. J. Bacteriol. 174:530-540); celD (Parker, L. L., and B. G. Hall. 1990. Characterization and nucleotide sequence of the cryptic cel operon ofEscherichia coliK12. Genetics. 124:455-471); chaB (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); chaC (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); cpxR (Danese, P. N., et al. 1995. The Cpx two-component signal transduction pathway ofEscherichia coliregulates transcription of the gene specifying the stress-inducible periplasmic protease, DegP. Genes Dev. 9:387-398); crl (Arnqvist, A., et al. 1992. The Crl protein activates cryptic genes for curli formation and fibronectin binding inEscherichia coliHB101. Mol. Microbiol. 6:2443-2452); cspA (Bae, W., et al. 1999. Characterization ofEscherichia colicspE, whose product negatively regulates transcription of cspA, the gene for the major cold shock protein. Mol. Microbiol. 31:1429-1441); cspE (Id.); csrA (Liu, M. Y., et al. 1995. The product of the pleiotropicEscherichia coligene csrA modulates glycogen biosynthesis via effects on mRNA stability. J. Bacteriol. 177:2663-2672); cynR (Anderson, P. M., et al. 1990. The cyanase operon and cyanate metabolism. FEMS Microbiol. Rev. 7:247-252; Sung, Y. C., and J. A. Fuchs. 1992. TheEscherichia coliK-12 cyn operon is positively regulated by a member of the lysR family. J. Bacteriol. 174:3645-3650); cysB (Jagura-Burdzy, G., and D. Hulanicka. 1981. Use of gene fusions to study expression of cysB, the regulatory gene of the cysteine regulon. J. Bacteriol. 147:744-751); cytR (Hammer-Jespersen, K., and A. Munch-Ptersen. 1975. Multiple regulation of nucleoside catabolizing enzymes: regulation of the deo operon by the cytR and deoR gene products. Mol. Gen. Genet. 137:327-335); dadQ (alnR) (Wild, J., and B. Obrepalska. 1982. Regulation of expression of the dadA gene encoding D-amino acid dehydrogenase inEscherichia coli:analysis of dadA-lac fusions and direction of dadA transcription. Mol. Gen. Genet. 186:405-410); dadR (alnR) (Wild, J., et al. 1985. Identification of the dadX gene coding for the predominant isozyme of alanine racemase inEscherichia coliK12. Mol. Gen. Genet. 198:315-322); deoR (nucR, tsc, nupG) (Hammer-Jespersen, K., and A. Munch-Ptersen. 1975. Multiple regulation of nucleoside catabolizing enzymes: regulation of the deo operon by the cytR and deoR gene products. Mol. Gen. Genet. 137:327-335); dgoR (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); dicA (Bejar, S., et al. 1988. Cell division inhibition gene dicB is regulated by a locus similar to lambdoid bacteriophage immunity loci. Mol. Gen. Genet. 212:11-19); dnaK (gro, groP, groPAB, groPC, groPF, grpC, grpF, seg) (Bochner, B. R., et al. 1986.Escherichia coliDnaK protein possesses a 5′-nucleotidase activity that is inhibited by AppppA. J. Bacteriol. 168:931-935); dniR (Kajie, S., et al. 1991. Molecular cloning and DNA sequence of dniR, a gene affecting anaerobic expression of theEscherichia colihexaheme nitrite reductase. FEMS Microbiol. Lett. 67:205-211); dsdC (Heincz, M. C., and E. McFall. 1978. Role of the dsdC activator in regulation of D-serine deaminase synthesis. J. Bacteriol. 136:96-103); ebgR (Hall, B. G., and N. D. Clarke. 1977. Regulation of newly evolved enzymes. III Evolution of the ebg repressor during selection for enhanced lactase activity. Genetics. 85:193-201); envY (Lundrigan, M. D., and C. F. Earhart. 1984. Gene envY ofEscherichia coliK-12 affects thermoregulation of major porin expression. J. Bacteriol. 157:262-268); envZ (ompB, perA, tpo) (Russo, F. D, and T. J. Silhavy. 1991. EnvZ controls the concentration of phosphorylated OmpR to mediate osmoregulation of the porin genes. J. Mol. Biol. 222:567-580); evgA (Nishino, K., and A. Yamaguichi. 2001. Overexpression of the response regulator evgA of the two-component signal transduction system modulates multidrug resistance conferred by multidrug resistance transporters. J. Bacteriol. 183:1455-1458); evgS (Id.); exuR (Portalier, R., et al. 1980. Regulation ofEscherichia coliK-12 hexuronate system genes: exu regulon. J. Bacteriol. 143:1095-1107); fadR (dec, ole, thdB) (Simons, R. W., et al. 1980. Regulation of fatty acid degradation inEscherichia coli:isolation and characterization of strains bearing insertion and temperature-sensitive mutations in gene fadR. J. Bacteriol. 142:621-632); fecI (Van Hove, B., et al. 1990. Novel two-component transmembrane transcription control: regulation of iron dicitrate transport inEscherichia coliK-12. J. Bacteriol. 172:6749-6758); fecR (Id.); fhlA (Maupin, J. A., and K. T. Shanmugam. 1990. Genetic regulation of formate hydrogenlyase ofEscherichia coli:role of the fhlA gene product as a transcriptional activator for a new regulatory gene, fhlB. J. Bacteriol. 172:4798-4806; Rossmann, R., et al. 1991. Mechanism of regulation of the formate-hydrogenlyase pathway by oxygen, nitrate, and pH: definition of the formate regulon. Mol. Microbiol. 5:2807-2814); fhlB (Maupin, J. A., and K. T. Shanmugam. 1990. Genetic regulation of formate hydrogenlyase ofEscherichia coli:role of the fhlA gene product as a transcriptional activator for a new regulatory gene, fhlB. J. Bacteriol. 172:4798-4806); fimB (pil) (Pallesen, L., et al. 1989. Regulation of the phase switch controlling expression oftype 1 fimbriae inEscherichia coli.Mol. Microbiol. 3:925-931); fimE (pilH) (Id.); flhC (flaI) (Liu, X., and P. Matsumura. 1994. The FlhD/FlhC complex, a transcriptional activator of theEscherichia coliflagellar class II operons. J. Bacteriol. 176:7345-7351); flhD (flhB) (Id.); fliA (flaD, rpoF) (Komeda, Y., et al. 1986. Transcriptional control of flagellar genes inEscherichia coliK-12. J. Bacteriol. 168:1315-1318); fnr (frdB, nirA, nirR) (Jones, H. M., and R. P. Gunsalus. 1987. Regulation ofEscherichia colifumarate reductase (frdABCD) operon expression by respiratory electron acceptors and the fnr gene product. J. Bacteriol. 169:3340-3349); fruR (fruC, shl) (Geerse, R. H., at al. The PEP: fructose phosphotransferase system inSalmonella typhimurium:FPr combines enzyme IIIFru and pseudo-HPr activities. Mol. Gen. Genet. 216:517-525); fucR (Zhu, Y., and E. C. Lin. 1986. An evolvant ofEscherichia colithat employs the L-fucose pathway also for growth on L-galactose and D-arabinose. J. Mol. Evol. 23:259-266); fur (Bagg, A., and J. B. Neilands. 1987. Ferric uptake regulation protein acts as a repressor, employing iron (II) as a cofactor to bind the operator of an iron transport operon inEscherichia coli.Biochemistry 26:5471-5477); gadR gene product fromLactococcus lactis(Sanders, J. W., et al. 1997. A chloride-inducible gene expression cassette and its use in induced lysis ofLactococcus lactis.Appl. Environ. Microbiol. 63:4877-4882); galR (von Wilcken-Bergmann, B., and B. Muller-Hill. 1982. Sequence of galR gene indicates a common evolutionary origin of lac and gal repressor inEscherichia coli.Proc. Natl. Acad. Sci. 79:2427-2431); galS (mglD) (Weickert., M. J., and S. Adhya. 1992. Isorepressor of the gal regulon inEscherichia coli.J. Mol. Biol. 226:69-83); galU (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); gatR (Nobelmann, B., and J. W. Lengeler. 1996. Molecular analysis of the gat genes fromEscherichia coliand of their roles in galactitol transport and metabolism. J. Bacteriol. 178:6790-6795); gcvA (Wilson, R. L., et al. 1993. Positive regulation of theEscherichia coliglycine cleavage enzyme system. J. Bacteriol. 175:902-904); glgS (Hengge-Aronis, R., et al. 1993. Osmotic regulation of rpoS-dependent genes inEscherichia coli.J. Bacteriol. 175:259-265; Yang, H., et al. 1996. Coordinate genetic regulation of glycogen catabolism and biosynthesis inEscherichia colivia the CsrA gene product. J. Bactgeriol. 178:1012-1017); glnB (Bueno, R., et al. 1985. Role of glnB and gInD gene products in regulation of the glnALG operon ofEscherichia coli.J. Bacteriol. 164:816-822); ginG (gln, ntrC) (Pahel, G., and B. Tyler. 1979. A new glnA-linked regulatory gene for glutamine synthetase inEscherichia coli.Proc. Natl. Acad. Sci. 76:4544-4548); glnL (glnR, ntrB) (MacNeil, T., et al. The products of glnL and glnG are bifunctional regulatory proteins. Mol. Gen. Genet. 188:325-333); glpR (Silhavy, T. J., et al. 1976. Periplasmic protein related to the sn-glycerol-3-phosphate transport system ofEscherichia coli.J. Bacteriol. 126:951-958); gltF (Castano, I., et al. gltF, a member of the gltBDF operon ofEscherichia coli,is involved in nitrogen-regulated gene expression. Mol. Microbiol. 6:2733-2741); gntR (Peekhaus, N., and T. Conway. 1998. Positive and negative transcriptional regulation of theEscherichia coligluconate regulon gene gntT by GntR and the cyclic AMP (cAMP)-cAMP receptor protein complex. J. Bacteriol. 180:1777-1785); hha (Neito, J. M., et al. The hha gene modulates haemolysin expression inEscherichia coli.Mol. Microbiol. 5:1285-1293); himD (hip) (Goosen, N., et al. 1984. Regulation of Mu transposition. II. TheEscherichia coliHimD protein positively controls two repressor promoters and the early promoter of bacteriophage Mu. Gene. 32:419-426); hrpB gene product fromPseudomonas solanacearum(Van Gijsegem, F., et al. 1995. The hrp gene locus ofPseudomonas solanacearum,which controls the production of a type III secretion system, encodes eight proteins related to components of the bacterial flagellar biogenesis complex. Mol. Microbiol. 15:1095-1114); hybF (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.), hycA (Hopper, S., et al. 1994. Regulated expression in vitro of genes coding for formate hydrogenlyase components ofEscherichia coli.J. Biol. Chem. 269:19597-19604); hydG (Leonhartsberger, S. et al. 2001. The hydH/G genes fromEscherichia colicode for a zinc and lead responsive two-component regulatory system. J. Mol. Biol. 307:93-105); hydH (Id.); iciA (Thony, B., et al. 1991. iciA, anEscherichia coligene encoding a specific inhibitor of chromosomal initiation of replication in vitro. Proc. Natl. Acad. Sci. 88:4066-4070); iclR (Maloy, S. R., and W. D. Nunn. 1982. Genetic regulation of the glyoxylate shunt inEscherichia coliK-12. J. Bacteriol. 149:173-180); ileR (avr, flrA) (Johnson, D. I., and R. L. Somerville. 1984. New regulatory genes involved in the control of transcription initiation at the thr and ilv promoters ofEscherichia coliK-12. Mol. Gen. Genet. 195:70-76); ilvR (Id.); ilvU (Fayerman, J. T., et al. 1979. ilvU, a locus inEscherichia coliaffecting the derepression of isoleucyl-tRNA synthetase and the RPC-5 chromatographic profiles of tRNAIle and tRNAVal. J. Bio. Chem. 254:9429-9440); ilvY (Wek, R. C., and G. W. Hatfield. 1988. Transcriptional activation at adjacent operators in the divergent-overlapping ilvY and ilvC promoters ofEscherichia coli.J. Mol. Biol. 203:643-663); inaA (White, S., et al. 1992. pH dependence and gene structure of inaA inEscherichia coli.J. Bacteriol. 174:1537-1543); inaR (Id.); kdgR (Nemoz, G., et al. 1976. Physiological and genetic regulation of the aldohexuronate transport system inEscherichia coli.J. Bacteriol. 127:706-718); lacI (Riggs, A. D, and S. Bourgeois. 1968. On the assay, isolation and characterization of the lac repressor. J. Mol. Biol. 34:361-364); leuO (Shi, X., and G. N. Bennett. 1995. Effects of multicopy LeuO on the expression of the acid-inducible lysine decarboxylase gene inEscherichia coli.J. Bacteriol. 177:810-814; Klauck, E., et al. 1997. The LysR-like regulator LeuO inEscherichia coliis involved in the translational regulation of rpoS by affecting the expression of the small regulatory DsrA-RNA. Mol. Microbiol. 25:559-569); leuR (Theall, G., et al. 1979. Regulation of the biosynthesis of aminoacyl-tRNA synthetases and of tRNA inEscherichia coli.IV. Mutants with increased levels of leucyl- or seryl-tRNA synthetase. Mol. Gen. Genet. 169:205-211); leuY (Morgan, S., et al. 1979. Regulation of biosynthesis of aminoacyl-transfer RNA synthetases and of transfer-RNA inEscherichia coli.Arch. Biol. Med. Exp. (Santiago) 12:415-426); lexA (Mount, D. W. 1977. A mutant ofEscherichia colishowing constitutive expression of the lysogenic induction and error-prone DNA repair pathways. Proc. Natl. Acad. Sci. 74:300-304; Little, J. W., et al. 1980. Cleavage of theEscherichia colilexA protein by the recA protease. Proc. Natl. Acad. Sci. 77:3225-3229); lldR (IctR) (Dong, J. M., et al. 1993. Three overlapping lct genes involved in L-lactate utilization byEscherichia coli.J. Bacteriol. 175:6671-6678); lpp (Brosius, J. Expression vectors employing lambda-, trp-, lac-, and lpp-derived promoters. 1988. Biotechnology. 10:205-225); lrhA (genR) (Bongaerts, J., et al. 1995. Transcriptional regulation of the proton translocating NADH dehydrogenase genes (nuoA-N) ofEscherichia coliby electron acceptors, electron donors and gene regulators. Mol. Microbiol. 16:521-534); lrp (ihb, livR, lss, lstR, oppI, rblA, mbf) (Ito, K., et al. Multiple control ofEscherichia colilysyl-tRNA synthetase expression involves a transcriptional repressor and a translational enhancer element. Proc. Natl. Acad. Sci. 90:302-306); lysR (Gicquel-Sanzey, B. and P. Cossart. 1982. Homologies between different procaryotic DNA-binding regulatory proteins and between their sites of action. EMBO J. 1:591-595; Stragier, P., et al. 1983. Regulation of diaminopimelate decarboxylase synthesis inEscherichia coli.II. Nucleotide sequence of the lysA gene and its regulatory region. J. Mol. Biol. 168:321-331); malI (Reidl, J., et al. 1989. MalI, a novel protein involved in regulation of the maltose system ofEscherichia coli,is highly homologous to the repressor proteins GalR, CytR, and LacI. J. Bacteriol. 171:4888-4499); malT (malA) (Bebarbouille, M., and M. Schwartz. Mutants which make more malT product, the activator of the maltose regulon inEscherichia coli.Mol. Gen. Genet. 178:589-595); marA (cpxB, soxQ) (Ariza, R. R., et al. Repressor mutations in the marRAB operon that activate oxidative stress genes and multiple antibiotic resistance inEscherichia coli.J. Bacteriol. 176:143-148); marB (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); marR (Ariza, R. R., et al. Repressor mutations in the marRAB operon that activate oxidative stress genes and multiple antibiotic resistance inEscherichia coli.J. Bacteriol. 176:143-148); melR (Williams, J., et al. 1994. Interactions between theEscherichia coliMelR transcription activator protein and operator sequences at the melAB promoter. Biochem. J. 300:757-763); metJ (Smith, A. A., et al. 1985. Isolation and characterization of the product of the methionine-regulatory gene metJ ofEscherichia coliK-12. Proc. Natl. Acad. Sci. 82:6104-6108; Shoeman, R., et al. 1985. Regulation of methionine synthesis inEscherichia coli:effect of metJ gene product and S-adenosylmethionine on the in vitro expression of the metB, metL and metJ genes. Biochem. Biophys. Res. Commun. 133:731-739); metR (Maxon, M. E., et al. 1989. Regulation of methionine synthesis inEscherichia coli:effect of the MetR protein on the expression of the metE and metR genes. Proc. Natl. Acad. Sci. 86:85-89); mglR (R-MG) (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); mhpR (Ferrandez, A., et al. 1997. Genetic characterization and expression in heterologous hosts of the 3-(3-hydroxyphenyl)propionate catabolic pathway ofEscherichia coliK-12. J. Bacteriol. 179:2573-2581); mhpS (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typllimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); micF (stc) (Aiba, H., et al. 1987. Function of micF as an antisense RNA in osmoregulatory expression of the ompF gene inEscherichia coli.J. Bacteriol. 169:3007-3012); mprA (emrR) (del Castillo, I., et al. 1990. mprA, anEscherichia coligene that reduces growth-phase-dependent synthesis of microcins B17 and C7 and blocks osmoinduction of proU when cloned on a high-copy-number plasmid. J. Bacteriol. 172:437-445); mtlR (Figge, R. M., et al. 1994. The mannitol repressor (MtlR) ofEscherichia coli.J. Bacteriol. 176:840-847); nagC (nagR) (Plumbridge, J. A. 1991. Repression and induction of the nag regulon ofEscherichia coliK-12: the roles of nagC and nagA in maintenance of the uninduced state. Mol. Microbiol. 5:2053-3062); narL (frdR, narR) (Stewart, V. 1982. Requirement of Fnr and NarL functions for nitrate reductase expression inEscherichia coliK-12. J. Bacteriol. 151:1320-1325; Miller, J. B., et al. 1987. Molybdenum-sensitive transcriptional regulation of the chlD locus ofEscherichia coli.J. Bacteriol. 169:1853-1860; Iuchi, S., and E. C. Lin. 1987. Molybdenum effector of fumarate reductase repression and nitrate reductase induction inEscherichia coli.J. Bacteriol. 169:3720-3725); narP (Rabin, R. S., and V. Stewart. 1993. Dual response regulators (NarL and NarP) interact with dual sensors (NarX and NarQ) to control nitrate- and nitrite-regulated gene expression inEscherichia coliK-12. J. Bacteriol. 175:3259-3268); nhaR (gene product fromE. coli(Rahav-Manor, O., et al. 1992. NhaR, a protein homologous to a family of bacterial regulatory proteins (LysR), regulates nhaA, the sodium proton antiporter gene inEscherichia coli.J. Biol. Chem. 267:10433-10438); ompR (cry, envZ, ompB) (Taylor, R. K., et al. Identification of OmpR: a positive regulatory protein controlling expression of the major outer membrane matrix porin proteins ofEscherichia coliK-12. J. Bacteriol. 147:255-258); oxyR (mor, momR) (VanBogelen, R. A, et al. 1987. Differential induction of heat shock, SOS, and oxidation stress regulons and accumulation of nucleotides inEscherichia coli.J. Bacteriol. 169:26-32); pdhR (Haydon, D. J., et al. A mutation causing constitutive synthesis of the pyruvate dehydrogenase complex inEscherichia coliis located within the pdhR gene. FEBS Lett. 336:43-47); phnF (Wanner, B. L., and W. W. Metcalf. 1992. Molecular genetic studies of a 10.9-kb operon inEscherichia colifor phosphonate uptake and biodegradation. FEMS Microbiol. Lett. 79:133-139); phoB (phoRc, phoT) (Pratt, C. 1980. Kinetics and regulation of cell-free alkaline phosphatase synthesis. J. Bacteriol. 143:1265-1274); phoP (Kasahara, M., et al. 1992. Molecular analysis of theEscherichia coliphoP-phoQ operon. J. Bacteriol. 174:492-498); phoQ (Id.); phoR (RIpho, nmpB, phoR1) (Bracha, M., and E. Yagil. 1969. Genetic mapping of the phoR regulator gene of alkaline phosphatase inEscherichia coli.J. Gen. Microbiol. 59:77-81); phoU (phoT) (Nakata, A., et al. 1984. Regulation of the phosphate regulon inEscherichia coliK-12: regulation of the negative regulatory gene phoU and identification of the gene product. J. Bacteriol. 159:979-985); poaR (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B.
• Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).[0346]Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); poxA (Chang, Y. Y., and J. E. Cronan Jr. 1982. Mapping nonselectable genes ofEscherichia coliby using transposon Tn10: location of a gene affecting pyruvate oxidase. J. Bacteriol. 151:1279-1289); proQ (Milner, J. L., and J. M. Wood. 1989. Insertion proQ220: :Tn5 alters regulation of proline porter II, a transporter of proline and glycine betaine inEscherichia coli.J. Bacteriol. 171:947-951); pspA (Weiner, L., et al. 1991. Stress-induced expression of theEscherichia coliphage shock protein operon is dependent on sigma 54 and modulated by positive and negative feedback mechanisms. Genes Dev. 5:1912-1923); pspB (Weiner, L., et al. 1991. Stress-induced expression of theEscherichia coliphage shock protein operon is dependent on sigma 54 and modulated by positive and negative feedback mechanisms. Genes Dev. 5:1912-1923); pspC (Weiner, L., et al. 1991. Stress-induced expression of theEscherichia coliphage shock protein operon is dependent on sigma 54 and modulated by positive and negative feedback mechanisms. Genes Dev. 5:1912-1923); pssR (Sparrow, C. P., and C. R. Raetz. 1983. A trans-acting regulatory mutation that causes overproduction of phosphatidylserine synthase inEscherichia coli.J. Biol. Chem. 258:9963-9967); purR (Meng, L. M., et al. 1990. Autoregulation of PurR repressor synthesis and involvement of purR in the regulation of purB, purC, purL, purMN and guaBA expression inEscherichia coli.Eur. J. Biochem. 187:373-379); putA (poaA) gene product fromSalmonella entericaserotype Typhimurium (Menzel, R., and J. Roth. 1981. Regulation of the genes for proline utilization inSalmonella typhimurium:autogenous repression by the putA gene product. J. Mol. Biol. 148:21-44); pyrI (Cunin, R., et al. 1985. Structure-function relationship in allosteric aspartate carbamoyltransferase fromEscherichia coli.I. Primary structure of a pyrI gene encoding a modified regulatory subunit. J. Mol. Biol. 186:707-713); rbsR (Lopilato, J. E., et al. 1984. D-ribose metabolism inEscherichia coliK-12: genetics, regulation, and transport. J. Bacteriol. 158:665-673); rcsA (Gottesman, S., et al. 1985. Regulation of capsular polysaccharide synthesis inEscherichia coliK-12: characterization of three regulatory genes. J. Bacteriol. 162:1111-1119); rcsB (Id.); rcsC (Id.); rcsF (Grevais, F. G., and G. R. Drapeau. 1992. Identification, cloning, and characterization of rcsF, a new regulator gene for exopolysaccharide synthesis that suppresses the division mutation ftsZ84 inEscherichia coliK-12. J. Bacteriol. 174:8016-8022); relB (Christensen, S. K., et al. 2001. RelE, a global inhibitor of translation, is activated during nutritional stress. Proc Natl. Acad. Sci. 98:14328-14333); rfaH (sfrB) (Pradel, E., and C. A. Schnaitman. 1991. Effect of rfaH (sfrB) and temperature on expression of rfa genes ofEscherichia coliK-12. J. Bacteriol. 173:6428-6431); rhaR (Tobin, J. F., and R. F. Schleif. 1987. Positive regulation of theEscherichia coliL-rhamnose operon is mediated by the products of tandemly repeated regulatory genes. J. Mol. Biol. 196:789-799); rhaS (Id.); rnk (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); rob (Skarstad, K., et al. A novel binding protein of the origin of theEscherichia colichromosome. J. Biol. Chem. 268:535-5370); rseA (mclA) (Missiakas, D., et al. 1997. Modulation of theEscherichia colisigmaE (RpoE) heat-shock transcription-factor activity by the RseA, RseB and RseC proteins. Mol. Microbiol. 24:355-371; De Las Penas, A. 1997. The sigmaE-mediated response to extracytoplasmic stress inEscherichia coliis transduced by RseA and RseB, two negative regulators of sigmaE. Mol. Microbiol. 24:373-385); rseB (Id.); rseC (Id.); rspA (Huisman, G. W., and T. Kolter. 1994. Sensing starvation: a homoserine lactone—dependent signaling pathway inEscherichia coli.Science. 265:537-539); rspB (Shafqat, J., et al. An ethanol-inducible MDR ethanol dehydrogenase/acetaldehyde reductase inEscherichia coli:structural and enzymatic relationships to the eukaryotic protein forms. Eur. J. Biochem. 263:305-311); rssA (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); rssB (Muffler, A., et al. 1996. The response regulator RssB controls stability of the sigma(S) subunit of RNA polymerase inEscherichia coli.EMBO J. 15:1333-1339); sbaA (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); sdaC (Id.); sdiA (Sitnikov, D. M., et al. 1996. Control of cell division inEscherichia coli:regulation of transcription of I involves both rpoS and SdiA-mediated autoinduction. Proc. Natl. Acad. Sci. 93:336-341); serR (Theall, G., et al . 1979. Regulation of the biosynthesis of aminoacyl-tRNA synthetases and of tRNA inEscherichia coli.IV. Mutants with increased levels of leucyl- or seryl-tRNA synthetase. Mol. Gen. Genet. 169:205-211); sfsA (Takeda, K., et al. 2001. Effects of theEscherichia colisfsA gene on mal genes expression and a DNA binding activity of SfsA. Biosci. Biotechnol. Biochem. 65:213-217); sfsB (nlp, sfs1) (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); soxR (Tsaneva, I. R., and B. Weiss. 1990. soxR, a locus governing a superoxide response regulon inEscherichia coliK-12. J. Bacteriol. 172:4197-4205); soxS (Wu, J., and B. Weiss. 1991. Two divergently transcribed genes, soxR and soxS, control a superoxide response regulon ofEscherichia coli.J. Bacteriol. 173:2864-2871); srlR (gutR) (Csonka, L. N., and A. J. Clark. 1979. Deletions generated by the transposon Tn10 in the srl recA region of theEscherichia coliK-12 chromosome. Genetics. 93:321-343); tdcA (Ganduri, Y. L., et al. 1993. TdcA, a transcriptional activator of the tdcABC operon ofEscherichia coli,is a member of the LysR family of proteins. Mol. Gen. Genet. 240:395-402); tdcR (Hagewood, B. T., et al. 1994. Functional analysis of the tdcABC promoter ofEscherichia coli:roles of TdcA and TdcR. J. Bacteriol. 176:6241-6220); thrS (Springer, M., et al. 1985. Autogenous control ofEscherichia colithreonyl-tRNA synthetase expression in vivo. J. Mol. Biol. 185:93-104); torR (Simon, G., et al. 1994. The torR gene ofEscherichia coliencodes a response regulator protein involved in the expression of the trimethylamine N-oxide reductase genes. J. Bacteriol. 176:5601-5606); treR (Horlacher, R., and W. Boos. 1997. Characterization of TreR, the major regulator of theEscherichia colitrehalose system. J. Biol. Chem. 272:13026-13032); trpR (Gunsalus, R. P., and C. Yanofsky. 1980. Nucleotide sequence and expression ofEscherichia colitrpR, the structural gene for the trp aporepressor. Proc. Natl. Acad. Sci. 77:7117-7121); tyrR (Camakaris, H., and J. Pittard. 1973. Regulation of tyrosine and phenylalanine biosynthesis inEscherichia coliK-12: properties of the tyrR gene product. J. Bacteriol. 115:1135-1144); uhpA (Kadner, R. J., and D. M. Shattuck-Eidens. 1983. Genetic control of the hexose phosphate transport system ofEscherichia coli:mapping of deletion and insertion mutations in the uhp region. J. Bacteriol. 155:1052-1061); uidR (gusR) (Novel, M., and G. Novel. 1976. Regulation of beta-glucuronidase synthesis inEscherichia coliK-12: pleiotropic constitutive mutations affecting uxu and uidA expression. J. Bacteriol. 127:418-432); uspA (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); uxuR (Novel, M., and G. Novel. 1976. Regulation of beta-glucuronidase synthesis inEscherichia coliK-12: pleiotropic constitutive mutations affecting uxu and uidA expression. J. Bacteriol. 127:418-432); wrbA (Yang, W., et al. 1993. A stationary-phase protein ofEscherichia colithat affects the mode of association between the trp repressor protein and operator-bearing DNA. Proc. Natl. Acad. Sci. 90:5796-5800); xapR (pndR) (Seeger, C., et al. 1995. Identification and characterization of genes (xapA, xapB, and xapR) involved in xanthosine catabolism inEscherichia coli.J. Bacteriol. 177:5506-5516); and xylR (Inouye, S., et al. 1987. Expression of the regulatory gene xylS on the TOL plasmid is positively controlled by the xylR gene product. Proc. Natl. Acad. Sci. 84:5182-5186);
• Regulatory elements, promoters and other expression elements and factors from prokaryotes other than[0347]E. coliandB. subtilisinclude without limitation ahyRI gene product fromAeromonas hydrophilaandAeromonas salmonicida(Swift, S., et al. 1997. Quorum sensing inAeromonas hydrophilaandAeromonas salmonicida:identification of the LuxRI homologs AhyRI and AsaRI and their cognate N-acylhomoserine lactone signal molecules. J. Bacteriol. 179:5271-5281); angR gene product fromVibrio anguillarum(Salinas, P. C., et al. 1989. Regulation of the iron uptake system inVibrio anguillarum:evidence for a cooperative effect between two transcriptional activators. Proc. Natl. Acad. Sci. 86:3529-3522); aphA gene product fromVibrio cholerae(Kovacikova, G., and K. Skorupski. 2001. Overlapping binding sites for the virulence gene regulators AphA, AphB and cAMP-CRP at theVibrio choleraetcpPH promoter. Mol. Microbiol. 41:393-407); aphB gene product fromVibrio cholerae(Kovachikova, G., and K. Skorupski. 2000. Differential activation of the tcpPH promoter by AphB determines biotype specificity of virulence gene expression inVibrio cholerae.J. Bacteriol. 182:3228-3238); comE gene product fromStreptococcus pneumoniae(Ween, O., et al. 1999. Identification of DNA binding sites for ComE, a key regulator of natural competence inStreptococcus pneumoniae.Mol. Microbiol. 33:817-827); esaI gene product fromPantoea stewartiisubsp. stewartii (von Bodman, S. B., et al. 1998. A negative regulator mediates quorum-sensing control of exopolysaccharide production inPantoea stewartiisubsp. stewartii. Proc. Natl. Acad. Sci. 95:7687-7692); esaR gene product fromPantoea stewartiisubsp. stewartii (Id.); expI gene product fromErwinia chrysanthemi(Nasser, W., et al. 1998. Characterization of theErwinia chrysanthemiexpI-expR locus directing the synthesis of two N-acyl-homoserine lactone signal molecules. Mol. Microbiol. 29:1391-1405); expR gene product fromErwinia chrysanthemi(Id.); gacA gene product fromPseudomonas aeruginosa(Pessi, G., and D. Haas. 2001. Dual control of hydrogen cyanide biosynthesis by the global activator GacA inPseudomonas aeruginosaPAO1. FEMS Microbiol. Lett. 200:73-78); hapR gene product fromVibrio cholerae(Jobling, M. G., and R. K. Holmes. Characterization of hapR, a positive regulator of theVibrio choleraeHA/protease gene hap, and its identification as a functional homologue of theVibrio harveyiluxR gene. Mol. Microbiol. 26:1023-1034); hlyR gene product fromVibrio cholerae(von Mechow, S., et al. 1985. Mapping of a gene that regulates hemolysin production inVibrio cholerae.J. Bacteriol. 163:799-802); hupR gene product fromVibrio vulnificus(Litwin, C. M., and J. Quackenbush. 2001. Characterization of a Vibrio vulnificus LysR homologue, HupR, which regulates expression of the haem uptake outer membrane protein, HupA. Microb. Pathog. 31:295-307); lasR gene product fromPseudomonas aerugenosa(Gambella, M. J., and B. H. Igleweski. 1991. Cloning and characterization of thePseudomonas aeruginosalasR gene, a transcriptional activator of elastase expression. J. Bacteriol. 173:3000-3009); leuO gene product fromSalmonella enterica serovar Typhimurium(Fang, M., and H. Y. Wu. 1998. A promoter relay mechanism for sequential gene activation. J. Bacteriol. 180:626-633); luxI gene product fromVibrio cholerae(Engebrecht, J., and M. Silverman. Nucleotide sequence of the regulatory locus controlling expression of bacterial genes for bioluminescence. Nucleic Acids Res. 5 15:10455-10467); luxO gene product fromVibrio cholerae(Bassler, B. L., et al. 1994. Sequence and function of LuxO, a negative regulator of luminescence inVibrio harveyi.Mol. Microbiol. 12:403-412); luxR gene product fromVibrio cholerae(Engebrecht, J., and M. Silverman. Nucleotide sequence of the regulatory locus controlling expression of bacterial genes for bioluminescence. Nucleic Acids Res. 15:10455-10467); phzR gene product fromPseudomonas aureofaciens(Pierson, L. S., et al. 1994. Phenazine antibiotic biosynthesis inPseudomonas aureofaciens30-84 is regulated by PhzR in response to cell density. J. Bacteriol. 176:3966-3974); rhlR gene product fromPseudomonas aeruginosa(Ochsner, U. A. et al. 1994. Isolation and characterization of a regulatory gene affecting rhamnolipid biosurfactant synthesis inPseudomonas aeruginosa.J. Bacteriol. 176:2044-2054); rsmA gene product fromErwinia carotovorasubsp.carotovora(Cui, Y., et al. 1995. Identification of a global repressor gene, rsmA, ofErwinia carotovorasubsp.carotovorathat controls extracellular enzymes, N-(3-oxohexanoyl)-L-homoserine lactone, and pathogenicity in soft-rotting Erwinia spp. J. Bacteriol. 177:5108-5115); rsmB gene product fromErwinia carotovorasubsp.carotovora(Cui, Y., et al. 1999. rsmC of the soft-rotting bacteriumErwinia carotovorasubsp.carotovoranegatively controls extracellular enzyme and harpin(Ecc) production and virulence by modulating levels of regulatory RNA (rsmB) and RNA-binding protein (RsmA). J. Bacteriol. 181:6042-6052); sirA gene product fromSalmonella enterica serovar Typhimurium(Goodier, R. I., and B. M. Ahmer. 2001. SirA orthologs affects both motility and virulence. J. Bacteriol. 183:2249-2258); taf gene product fromVibrio cholerae(Salinas, P. C., et al. 1989. Regulation of the iron uptake system inVibrio anguillarum:evidence for a cooperative effect between two transcriptional activators. Proc. Natl. Acad. Sci. 86:3529-3522); tcpP gene product fromVibrio cholerae(Hase, C. C., and J. J. Mekalanos. 1998. TcpP protein is a positive regulator of virulence gene expression inVibrio cholerae.Proc. Natl. Acad. Sci. 95:730-734); toxR gene product fromVibrio cholerae(Miller, V. L., and J. J. Mekalanos. 1984. Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc. Natl. Acad. Sci. 81:3471-4375); toxS gene product fromVibrio cholerae(Miller, V. L., et al. 1989. Identification of toxS, a regulatory gene whose product enhances toxR-mediated activation of the cholera toxin promoter. J. Bacteriol. 171:1288-1293); toxT fromVibrio cholerae(Kaufman, M. R., et al. 1993. Biogenesis and regulation of theVibrio choleraetoxin-coregulated pilus: analogies to other virulence factor secretory systems. Gene. 126:43-49); traM gene product fromAgrobacterium tumefaciens(Faqua, C., et al. 1995. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene. J. Bacteriol. 177:1367-1373); traR gene product fromAgrobacterium tumefaciens(Piper, K. R., et al. 1993. Conjugation factor ofAgrobacterium tumefaciensregulates Ti plasmid transfer by autoinduction. Nature. 362:448-450); vicH gene product fromVibrio cholerae(Tendeng, C., et al. 2000. Isolation and characterization of vicH, encoding a new pleiotropic regulator inVibrio cholerae.J. Bacteriol. 182:2026-2032); vspR gene product fromVibrio cholerae(Yildiz, F. H., et al. 2001. VpsR, a Member of the Response Regulators of the Two-Component Regulatory Systems, Is Required for Expression of vps Biosynthesis Genes and EPS(ETr)-Associated Phenotypes in Vibrio cholerae O1 El Tor. J. Bacteriol. 183:1716-1726).
• II.C.5.b.[0348]Bacillus subtilis
• Regulatory elements, promoters and other expression elements and expression elements from[0349]B subtilisinclude but are not limited to abrB (Perego, M., et al. 1988. Structure of the gene for the transition state regulator, abrB: regulator synthesis is controlled by the spo0A sporulation gene inBacillus subtilis.Mol. Microbiol. 2:698-699); acoR (Ali, N. O., et al. 2001. Regulation of the acetoin catabolic pathway is controlled by sigma L inBacillus subtilis.J. Bacteriol. 183:2497-2504); ahrC (Klinger, U., et al. 1995. A binding site for activation by theBacillus subtilisAhrC protein, a repressor/activator of arginine metabolism. Mol. Gen. Genet. 248:329-340); alaR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); alsR (Renna, M. C., et al. 1993. Regulation of theBacillus subtilisalsS, alsD, and alsR genes involved in post-exponential-phase production of acetoin. J. Bacteriol. 175:3863-3875); ansR (Sun, D., and P. Setlow. 1993. Cloning and nucleotide sequence of theBacillus subtilisansR gene, which encodes a repressor of the ans operon coding for L-asparaginase and L-aspartase. J. Bacteriol. 175:2501-2506); araR (Sa-Nogueira, I., and L. J. Mota. 1997. Negative regulation of L-arabinose metabolism inBacillus subtilis:characterization of the araR (araC) gene. J. Bacteriol. 179:1598-1608); arfM (Marino, M., et al. 2001. Modulation of anaerobic energy metabolism ofBacillus subtilisby arfM (ywiD). J. Bacteriol. 183:6815-6821); arsR (Rosenstein, R., et al. 1992. Expression and regulation of the antimonite, arsenite, and arsenate resistance operon ofStaphylococcus xylosusplasmid pSX267. J. Bacteriol. 174:3676-3683); azlB (Belitsky, B. R., et al. 1997. An lrp-like gene ofBacillus subtilisinvolved in branched-chain amino acid transport. J. Bacteriol. 179:54485457); birA (Bower, S., et al. 1995. Cloning and characterization of theBacillus subtilisbirA gene encoding a repressor of the biotin operon. J. Bacteriol. 177:2572-2575); bkdR (Bebarbouille, M., et al. 1999. Role of bkdR, a transcriptional activator of the sigL-dependent isoleucine and valine degradation pathway inBacillus subtilis.J. Bacteriol. 181:2059-2066); bltR (Ahmed, M., et al. 1995. Two highly similar multidrug transporters ofBacillus subtiliswhose expression is differentially regulated. J. Bacteriol. 177:3904-3910); bmrR (Ahmed, M., et al. 1994. A protein that activates expression of a multidrug efflux transporter upon binding the transporter substrates. J. Biol. Chem. 269:28506-28513); ccpA (Henkin, T. M., et al. 1991. Catabolite repression of alpha-amylase gene expression inBacillus subtilisinvolves a trans-acting gene product homologous to theEscherichia colilacl and galR repressors. Mol. Microbiol. 5:575-584); ccpB (Chauvaux, S., et al. 1998. CcpB, a novel transcription factor implicated in catabolite repression inBacillus subtilis.J. Bacteriol. 180:491-497); ccpC (Jourlin-Castelli, C., et al. 2000. CcpC, a novel regulator of the LysR family required for glucose repression of the citB gene inBacillus subtilis.J. Mol. Biol. 295:865-878); cggR (Fillinger, S., et al. 2000. Two glyceraldehyde-3-phosphate dehydrogenases with opposite physiological roles in a nonphotosynthetic bacterium. J. Biol. Chem. 275:14031-14037); cheB (Bischoff, D. S., and G. W. Ordal. 1991. Sequence and characterization ofBacillus subtilisCheB, a homolog ofEscherichia coliCheY, and its role in a different mechanism of chemotaxis. J. Biol. Chem. 266:12301-12305); cheY (Bischoff, D. S., et al. 1993. Purification and characterization ofBacillus subtilisCheY. Biochemistry 32:9256-9261); citR (Jin, S., and A. L. Sonenshein. 1994. Transcriptional regulation ofBacillus subtiliscitrate synthase genes. J. Bacteriol. 176:4680-4690); citT (Yamamoto, H., et al. 2000. The CitST two-component system regulates the expression of the Mg-citrate transporter inBacillus subtilis.Mol. Microbiol. 37:898-912); codY (Slack, F. J., et al. 1995. A gene required for nutritional repression of theBacillus subtilisdipeptide permease operon. Mol. Microbiol. 15:689-702); comA (Nakano, M. M., and P. Zuber. 1989. Cloning and characterization of srfB, a regulatory gene involved in surfactin production and competence inBacillus subtilis.J. Bacteriol. 171:5347-5353); comK (Msadek, T., et al. 1994. MecB ofBacillus subtilis,a member of the ClpC ATPase family, is a pleiotropic regulator controlling competence gene expression and growth at high temperature. Proc. Natl. Acad. Sci. 91:5788-5792); comQ (Weinrauch, Y., et al. 1991. Sequence and properties of comQ, a new competence regulatory gene ofBacillus subtilis.J. Bacteriol. 173:5685-5693); cssR (Hyyrylainen, H. L., et al. 2001. A novel two-component regulatory system inBacillus subtilisfor the survival of severe secretion stress. Mol. Microbiol. 41:1159-1172); ctsR (Kruger, E., and M. Hecker. 1998. The first gene of the Bacillus subtilis clpC operon, ctsR, encodes a negative regulator of its own operon and other class III heat shock genes. J. Bacteriol. 180:6681-6688); dctR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); degA (Bussey, L. B., and R. L. Switzer. 1993. The degA gene product accelerates degradation ofBacillus subtilisphosphoribosylpyrophosphate amidotransferase inEscherichia coli.J. Bacteriol. 175:6348-6353); degU (Msadek, T., et al. 1990. Signal transduction pathway controlling synthesis of a class of degradative enzymes inBacillus subtilis:expression of the regulatory genes and analysis of mutations in degS and degU. J. Bacteriol. 172:824-834); deoR (Saxild, H. H., et al. 1996. Dra-nupC-pdp operon ofBacillus subtilis:nucleotide sequence, induction by deoxyribonucleosides, and transcriptional regulation by the deoR-encoded DeoR repressor protein. J. Bacteriol. 178:424-434); exuR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); frn (Cruz Ramos, H., et al. 1995. Anaerobic transcription activation inBacillus subtilis:identification of distinct FNR-dependent and -independent regulatory mechanisms. EMBO J. 14:5984-5994); fruR (Saier, M. H. Jr. 1996. Cyclic AMP-independent catabolite repression in bacteria. FEMS Microbiol. Lett. 138:97-103); fur (Chen, L., et al. 1993. Metalloregulation inBacillus subtilis:isolation and characterization of two genes differentially repressed by metal ions. J. Bacteriol. 175:5428-5437); gabR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); gerE (Holand, S. K., et al. 1987. The possible DNA-binding nature of the regulatory proteins, encoded by spoIID and gerE, involved in the sporulation ofBacillus subtilis.J. Gen. Microbiol. 133:2381-2391); glcR (Stulke, J., et al. 2001. Characterization of glucose-repression-resistant mutants ofBacillus subtilis:identification of the glcR gene. Arch. Microbiol. 175:441-449); glcT (Paulsen, I. T., et al. 1998. Characterization of glucose-specific catabolite repression-resistant mutants ofBacillus subtilis:identification of a novel hexose: H+ symporter. J. Bacteriol. 180:498-504); glnR (Schreier, H. J., et al. 1989. Regulation ofBacillus subtilisglutamine synthetase gene expression by the product of the glnR gene. J. Mol. Biol. 210:51-63); glpP (Holmberg, C., and B. Rutberg. 1991. Expression of the gene encoding glycerol-3-phosphate dehydrogenase (glpD) inBacillus subtilisis controlled by antitermination. Mol. Microbiol. 5:2891-2900); gltC (Bohannon, D. E. and A. L. Sonenshein. 1989. Positive regulation of glutamate biosynthesis inBacillus subtilis.J. Bacteriol. 171:4718-4727); gltR (Belitsky, B. R., and A. L. Sonenshein. 1997. Altered transcription activation specificity of a mutant form ofBacillus subtilisGltR, a LysR family member. J. Bacteriol. 179:1035-1043); gntR (Fujita, Y., and T. Fujita. 1987. The gluconate operon gnt ofBacillus subtilisencodes its own transcriptional negative regulator. Proc. Natl. Acad. Sci. 84:4524-4528); gutR (Ye, R., et al. 1994. Glucitol induction inBacillus subtilisis mediated by a regulatory factor, GutR. J. Bacteriol. 176:3321-3327); hpr (Perego, M., and J. A. Hoch. 1988. Sequence analysis and regulation of the hpr locus, a regulatory gene for protease production and sporulation inBacillus subtilis.J. Bacteriol. 170:2560-2567); hrcA (Schulz, A., and W. Schumann. 1996. hrcA, the first gene of theBacillus subtilisdnaK operon encodes a negative regulator of class I heat shock genes. J. Bacteriol. 178:1088-1093); hutP (Oda, M., et al. 1992. Analysis of the transcriptional activity of the hut promoter inBacillus subtilisand identification of a cis-acting regulatory region associated with catabolite repression downstream from the site of transcription. Mol. Microbiol. 6:2573-2582); hxlR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); iolR (Yoshida, K. I., et al. 1999. Interaction of a repressor and its binding sites for regulation of theBacillus subtilisiol divergon. J. Mol. Biol. 285:917-929); kdgR (Pujic, P., et al. 1998. The kdgRKAT operon ofBacillus subtilis:detection of the transcript and regulation by the kdgR and ccpA genes. Microbiology. 144:3111-3118); kipR (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); lacR (Errington, J., and C. H. Vogt. 1990. Isolation and characterization of mutations in the gene encoding an endogenousBacillus subtilisbeta-galactosidase and its regulator. J. Bacteriol. 172:488-490); levR (Bebarbouille, M., et al. 1991. The transcriptional regulator LevR ofBacillus subtilishas domains homologous to both sigma 54- and phosphotransferase system-dependent regulators. Proc. natl. Acad. Sci. 88:2212-2216); lexA (Lovett, C. M. Jr., and J. W. Roberts. 1985. Purification of a RecA protein analogue fromBacillus subtilis.J. Biol. Chem. 260:3305-3313); licR (Tobisch, S., et a. 1997. Identification and characterization of a new beta-glucoside utilization system inBacillus subtilis.J. Bacteriol. 179:496-506); licT (Le Coq, D., et al. 1995. New beta-glucoside (bgl) genes inBacillus subtilis:the bglP gene product has both transport and regulatory functions similar to those of BglF, itsEscherichia colihomolog. J. Bacteriol. 177:1527-25 1535); lmrA (Kumano, M., et al. 1997. A 32 kb nucleotide sequence from the region of the lincomycin-resistance gene (22 degrees-25 degrees) of theBacillus subtilischromosome and identification of the site of the lin-2 mutation. Microbiology. 143:2775-2782); lrpA gene product fromPyrococcus furiosus(Brinkman, A. B., et al. 2000. An Lrp-like transcriptional regulator from the archaeonPyrococcus furiosusis negatively autoregulated. J. Biol. Chem. 275:38160-38169); lrpB (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); lrpC (Beloin, C., et al. 1997. Characterization of an lrp-like (lrpC) gene fromBacillus subtilis.Mol. Gen. Genet. 256:63-71); lytR (Huang, X., and J. D. Helmann. 1998. Identification of target promoters for theBacillus subtilissigma X factor using a consensus-directed search. J. Mol. Biol. 279:165-173); lytT (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); manR gene product fromListeria monocytogenes(Dalet, K., et al. 2001. A sigma(54)-dependent PTS permease of the mannose family is responsible for sensitivity ofListeria monocytogenesto mesentericin Y105. Microbiology. 147:3263-3269); mntR (Que, Q., and J. D. Helmann. 2000. Manganese homeostasis inBacillus subtilisis regulated by MntR, a bifunctional regulator related to the diphtheria toxin repressor family of proteins. Mol. Microbiol. 35:1454-1468); msmR gene product fromStreptococcus mutans(Russell, R. R., et al. 1992. A binding protein-dependent transport system inStreptococcus mutansresponsible for multiple sugar metabolism. J. Biol. Chem. 267:4631-4637); mta (Baranova, N. N., et al. 1999. Mta, a global MerR-type regulator of theBacillus subtilismultidrug-efflux transporters. Mol. Microbiol. 31:1549-1559); mtlR (Henstra, S. A., et al. 1999. TheBacillus stearothermophilusmannitol regulator, MtlR, of the phosphotransferase system. A DNA-binding protein, regulated by HPr and iicbmtl-dependent phosphorylation. J. Biol. Chem. 274:4754-4763); mtrB (Gollnick, P., et al. 1990. The mtr locus is a two-gene operon required for transcription attenuation in the trp operon ofBacillus subtilis.Proc. Natl. Acad. Sci. 87:8726-8730); nhaX (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); toxR gene product fromVibrio cholerae(Miller, V. L., and J. J. Mekalanos. 1984. Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc. Natl. Acad. Sci. 81:3471-3475); padR gene product fromPediococcus pentosaceus(Barthelmebs, L., et al. 2000. Inducible metabolism of phenolic acids inPediococcus pentosaceusis encoded by an autoregulated operon which involves a new class of negative transcriptional regulator. J. Bacteriol. 182:6724-6731); paiA (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); paiB (Id.); perA (Id.); phoP (Birkey, S. M., et al. 1994. A pho regulon promoter induced under sporulation conditions. Gene. 147:95-100); pksA (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); pucR (Schultz, A. C., et al. 2001. Functional analysis of 14 genes that constitute the purine catabolic pathway inBacillus subtilisand evidence for a novel regulon controlled by the PucR transcription activator. J. Bacteriol. 183:3293-3302); purR (Weng, M., et al. 1995. Identification of theBacillus subtilispur operon repressor. Proc. Natl. Acad. Sci. 92:7455-7459); pyrR (Martinussen, J., et al. 1995. Two genes encoding uracil phosphoribosyltransferase are present inBacillus subtilis.J. Bacteriol. 177:271-274); rbsR (Rodionov, D. A., et al. 2001. Transcriptional regulation of pentose utilisation systems in the Bacillus/Clostridium group of bacteria. FEMS Microbiol. Lett. 205:305-314); resD (Suin, G., et al. 1996. Regulators of aerobic and anaerobic respiration inBacillus subtilis.J. Bacteriol. 178:1374-1385); rocR (Gardan, R., et al. 1997. Role of the transcriptional activator RocR in the arginine-degradation pathway ofBacillus subtilis.Mol. Microbiol. 24:825-837); rsiX (Tortosa, P., et al. 2000. Characterization of ylbF, a new gene involved in competence development and sporulation inBacillus subtilis.Mol. Microbiol. 35:1110-1119); sacT (Debarbouille, M., et al. 1990. The sacT gene regulating the sacPA operon inBacillus subtilisshares strong homology with transcriptional antiterminators. J. Bacteriol. 172:3966-3973); sacV (Wong, S. L., et al. 1988. Cloning and nucleotide sequence of senN, a novel ‘Bacillus natto’ (B. subtilis) gene that regulates expression of extracellular protein genes. J. Gen. Microbiol. 134:3269-3276); sacY (Steinmetz, M., et al 1989. Induction of saccharolytic enzymes by sucrose inBacillus subtilis:evidence for two partially interchangeable regulatory pathways. J. Bacteriol. 171:1519-1523); senS (Wang, L. F., and R. H. Dori. 1990. Complex character of senS, a novel gene regulating expression of extracellular-protein genes ofBacillus subtilis.J. Bacteriol. 172:1939-1947); sinR (Bai, U., et al. 1993. SinI modulates the activity of SinR, a developmental switch protein ofBacillus subtilis,by protein-protein interaction. Genes Dev. 7:139-148); slr (Asayama, M., et al. 1998. Translational attenuation of theBacillus subtilisspo0B cistron by an RNA structure encompassing the initiation region. Nucleic Acids Res. 26:824-830); spla (Fajardo-Cavazos, P., and W. L. Nicholson. 2000. The TRAP-like SplA protein is a trans-acting negative regulator of spore photoproduct lyase synthesis duringBacillus subtilissporulation. J. Bacteriol. 182:555-560); spo0A (Smith, I., et al. 1991. The role of negative control in sporulation. Res. Microbiol. 142:831-839); spo0F (Lewandoski, M., et al. 1986. Transcriptional regulation of the spo0F gene ofBacillus subtilis.J. Bacteriol. 168:870-877); spoIIID (Kunkel, B., et al. 1989. Temporal and spatial control of the mother-cell regulatory gene spoIIID ofBacillus subtilis.Genes. Dev. 3:1735-1744); spoVT (Bagyan, I, et al. 1996. A compartmentalized regulator of developmental gene expression inBacillus subtilis.J. Bacteriol. 178:4500-4507); tenA (Pang, A. S., et al. 1991. Cloning and characterization of a pair of novel genes that regulate production of extracellular enzymes inBacillus subtilis.J. Bacteriol. 173:46-54); ten1 (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); tnrA (Wray, L. V., Jr., et al. 1996. TnrA, a transcription factor required for global nitrogen regulation inBacillus subtilis.Proc. Natl. Acad. Sci. 93:8841-8845); treR (Schock, F., and M. K. Dahl. 1996. Expression of the tre operon ofBacillus subtilis168 is regulated by the repressor TreR. J. Bacteriol. 178:4576-4581); xre (McDonnell, G. E., et al. 1994. Genetic control of bacterial suicide: regulation of the induction of PBSX inBacillus subtilis.J. Bacteriol. 176:5820-5830); xylR gene product fromBacillus megaterium(Rygus, T., et al. 1991. Molecular cloning, structure, promoters and regulatory elements for transcription of theBacillus megateriumencoded regulon for xylose utilization. Arch. Microbiol. 155:535:542); yacF (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D. C.); and zur (Gaballa, A., and J. D. Helmann. 1998. Identification of a zinc-specific metalloregulatory protein, Zur, controlling zinc transport operons inBacillus subtilis.J. Bacteriol. 180:5815-5821).
• II.C.5.c. Other Eubacteria[0350]
• Regulatory elements, promoters and other expression elements and factors from prokaryotes other than[0351]E. coliandB. subtilisinclude without limitation ahyRI gene product fromAeromonas hydrophilaandAeromonas salmonicida(Swift, S., et al. 1997. Quorum sensing inAeromonas hydrophilaandAeromonas salmonicida:identification of the LuxRI homologs AhyRI and AsaRI and their cognate N-acylhomoserine lactone signal molecules. J. Bacteriol. 179:5271-5281); angR gene product fromVibrio anguillarum(Salinas, P. C., et al. 1989. Regulation of the iron uptake system inVibrio anguillarum:evidence for a cooperative effect between two transcriptional activators. Proc. Natl. Acad. Sci. 86:3529-3522); aphA gene product fromVibrio cholerae(Kovacikova, G., and K. Skorupski. 2001. Overlapping binding sites for the virulence gene regulators AphA, AphB and cAMP-CRP at theVibrio choleraetcpPH promoter. Mol. Microbiol. 41:393-407); aphB gene product fromVibrio cholerae(Kovachikova, G., and K. Skorupski. 2000. Differential activation of the tcpPH promoter by AphB determines biotype specificity of virulence gene expression inVibrio cholerae.J. Bacteriol. 182:3228-3238); comE gene product fromStreptococcus pneumoniae(Ween, O., et al. 1999. Identification of DNA binding sites for ComE, a key regulator of natural competence inStreptococcus pneumoniae.Mol. Microbiol. 33:817-827); esaI gene product fromPantoea stewartiisubsp.stewartii(von Bodman, S. B., et al. 1998. A negative regulator mediates quorum-sensing control of exopolysaccharide production inPantoea stewartiisubsp.stewartii.Proc. Natl. Acad. Sci. 95:7687-7692); esaR gene product fromPantoea stewartiisubsp.stewartii(Id.); expI gene product fromErwinia chrysanthemi(Nasser, W., et al. 1998. Characterization of theErwinia chrysanthemiexpI-expR locus directing the synthesis of two N-acyl-homoserine lactone signal molecules. Mol. Microbiol. 29:1391-1405); expR gene product fromErwinia chrysanthemi(Id.); gacA gene product fromPseudomonas aeruginosa(Pessi, G., and D. Haas. 2001. Dual control of hydrogen cyanide biosynthesis by the global activator GacA in Pseudomonas aeruginosa PAO1. FEMS Microbiol. Lett. 200:73-78); hapR gene product fromVibrio cholerae(Jobling, M. G., and R. K. Holmes. Characterization of hapR, a positive regulator of theVibrio choleraeHA/protease gene hap, and its identification as a functional homologue of theVibrio harveyiluxR gene. Mol. Microbiol. 26:1023-1034); hlyR gene product fromVibrio cholerae(von Mechow, S., et al. 1985. Mapping of a gene that regulates hemolysin production inVibrio cholerae.J. Bacteriol. 163:799-802); hupR gene product fromVibrio vulnificus(Litwin, C. M., and J. Quackenbush. 2001. Characterization of aVibrio vulnificusLysR homologue, HupR, which regulates expression of the haem uptake outer membrane protein, HupA. Microb. Pathog. 31:295-307); lasR gene product fromPseudomonas aerugenosa(Gambella, M. J., and B. H. Igleweski. 1991. Cloning and characterization of thePseudomonas aeruginosalasR gene, a transcriptional activator of elastase expression. J. Bacteriol. 173:3000-3009); leuO gene product fromSalmonella enterica serovar Typhimurium(Fang, M., and H. Y. Wu. 1998. A promoter relay mechanism for sequential gene activation. J. Bacteriol. 180:626-633); luxI gene product fromVibrio cholerae(Engebrecht, J., and M. Silverman. Nucleotide sequence of the regulatory locus controlling expression of bacterial genes for bioluminescence. Nucleic Acids Res. 15:10455-10467); luxO gene product fromVibrio cholerae(Bassler, B. L., et al. 1994. Sequence and function of LuxO, a negative regulator of luminescence inVibrio harveyi.Mol. Microbiol. 12:403-412); luxR gene product fromVibrio cholerae(Engebrecht, J., and M. Silverman. Nucleotide sequence of the regulatory locus controlling expression of bacterial genes for bioluminescence. Nucleic Acids Res. 15:10455-10467); phzR gene product fromPseudomonas aureofaciens(Pierson, L. S., et al. 1994. Phenazine antibiotic biosynthesis inPseudomonas aureofaciens30-84 is regulated by PhzR in response to cell density. J. Bacteriol. 176:3966-3974); rhlR gene product fromPseudomonas aeruginosa(Ochsner, U. A. et al. 1994. Isolation and characterization of a regulatory gene affecting rhamnolipid biosurfactant synthesis inPseudomonas aeruginosa.J. Bacteriol. 176:2044-2054); rsmA gene product fromErwinia carotovorasubsp.carotovora(Cui, Y., et al. 1995. Identification of a global repressor gene, rsmA, ofErwinia carotovorasubsp.carotovorathat controls extracellular enzymes, N-(3-oxohexanoyl)-L-homoserine lactone, and pathogenicity in soft-rotting Erwinia spp. J.
• Bacteriol. 177:5108-5115); rsmB gene product from[0352]Erwinia carotovorasubsp.carotovora(Cui, Y., et al. 1999. rsmC of the soft-rotting bacteriumErwinia carotovorasubsp.carotovoranegatively controls extracellular enzyme and harpin(Ecc) production and virulence by modulating levels of regulatory RNA (rsmB) and RNA-binding protein (RsmA). J. Bacteriol. 181:6042-6052); sirA gene product fromSalmonella enterica serovar Typhimurium(Goodier, R. I., and B. M. Ahmer. 2001. SirA orthologs affects both motility and virulence. J. Bacteriol. 183:2249-2258); taf gene product fromVibrio cholerae(Salinas, P. C., et al. 1989. Regulation of the iron uptake system inVibrio anguillarum:evidence for a cooperative effect between two transcriptional activators. Proc. Natl. Acad. Sci. 86:3529-3522); tcpP gene product fromVibrio cholerae(Hase, C. C., and J. J. Mekalanos. 1998. TcpP protein is a positive regulator of virulence gene expression inVibrio cholerae.Proc. Natl. Acad. Sci. 95:730-734); toxR gene product fromVibrio cholerae(Miller, V. L., and J. J. Mekalanos. 1984. Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc. Natl. Acad. Sci. 81:3471-4375); toxS gene product fromVibrio cholerae(Miller, V. L., et al. 1989. Identification of toxS, a regulatory gene whose product enhances toxR-mediated activation of the cholera toxin promoter. J. Bacteriol. 171:1288-1293); toxT fromVibrio cholerae(Kaufman, M. R., et al. 1993. Biogenesis and regulation of theVibrio choleraetoxin-coregulated pilus: analogies to other virulence factor secretory systems. Gene. 126:43-49); traM gene product fromAgrobacterium tumefaciens(Faqua, C., et al. 1995. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene. J. Bacteriol. 177:1367-1373); traR gene product fromAgrobacterium tumefaciens(Piper, K. R., et al. 1993. Conjugation factor ofAgrobacterium tumefaciensregulates Ti plasmid transfer by autoinduction. Nature. 362:448-450); vicH gene product fromVibrio cholerae(Tendeng, C., et al. 2000. Isolation and characterization of vicH, encoding a new pleiotropic regulator inVibrio cholerae.J. Bacteriol. 182:2026-2032); vspR gene product fromVibrio cholerae(Yildiz, F. H., et al. 2001. VpsR, a Member of the Response Regulators of the Two-Component Regulatory Systems, Is Required for Expression of vps Biosynthesis Genes and EPS(ETr)-Associated Phenotypes inVibrio choleraeO1 E1 Tor. J. Bacteriol. 183:1716-1726); gadR gene product fromLactococcus lactis(Sanders, J. W., et al. 1997. A chloride-inducible gene expression cassette and its use in induced lysis ofLactococcus lactis.Appl. Environ. Microbiol. 63:4877-4882); hrpB gene product fromPseudomonas solanacearum(Van Gijsegem, F., et al. 1995. The hrp gene locus ofPseudomonas solanacearum,which controls the production of a type III secretion system, encodes eight proteins related to components of the bacterial flagellar biogenesis complex. Mol. Microbiol. 15:1095-1114);carotovorasubsp.carotovora(Cui, Y., et al. 1995. Identification of a global repressor gene, rsmA, ofErwinia carotovorasubsp.carotovorathat controls extracellular enzymes, N-(3-oxohexanoyl)-L-homoserine lactone, and pathogenicity in soft-rotting Erwinia spp. J. Bacteriol. 177:5108-5115); rsmB gene product fromErwinia carotovorasubsp.carotovora(Cui, Y., et al. 1999. rsmC of the soft-rotting bacteriumErwinia carotovorasubsp.carotovoranegatively controls extracellular enzyme and harpin(Ecc) production and virulence by modulating levels of regulatory RNA (rsmB) and RNA-binding protein (RsmA). J. Bacteriol. 181:6042-6052); sirA gene product fromSalmonella enterica serovar Typhimurium(Goodier, R. I., and B. M. Ahmer. 2001. SirA orthologs affects both motility and virulence. J. Bacteriol. 183:2249-2258); taf gene product fromVibrio cholerae(Salinas, P. C., et al. 1989. Regulation of the iron uptake system inVibrio anguillarum:evidence for a cooperative effect between two transcriptional activators. Proc. Natl. Acad. Sci. 86:3529-3522); tcpP gene product fromVibrio cholerae(Hase, C. C., and J. J. Mekalanos. 1998. TcpP protein is a positive regulator of virulence gene expression inVibrio cholerae.Proc. Natl. Acad. Sci. 95:730-734); toxR gene product fromVibrio cholerae(Miller, V. L., and J. J. Mekalanos. 1984. Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc. Natl. Acad. Sci. 81:3471-4375); toxS gene product fromVibrio cholerae(Miller, V. L., et al. 1989. Identification of toxS, a regulatory gene whose product enhances toxR-mediated activation of the cholera toxin promoter. J. Bacteriol. 171:1288-1293); toxT fromVibrio cholerae(Kaufman, M. R., et al. 1993. Biogenesis and regulation of theVibrio choleraetoxin-coregulated pilus: analogies to other virulence factor secretory systems. Gene. 126:43-49); traM gene product fromAgrobacterium tumefaciens(Faqua, C., et al. 1995. Activity of the Agrobacterium Ti plasmid conjugal transfer regulator TraR is inhibited by the product of the traM gene. J. Bacteriol. 177:1367-1373); traR gene product fromAgrobacterium tumefaciens(Piper, K. R., et al. 1993. Conjugation factor ofAgrobacterium tumefaciensregulates Ti plasmid transfer by autoinduction. Nature. 362:448-450); vicH gene product fromVibrio cholerae(Tendeng, C., et al. 2000. Isolation and characterization of vicH, encoding a new pleiotropic regulator inVibrio cholerae.J. Bacteriol. 182:2026-2032); vspR gene product fromVibrio cholerae(Yildiz, F. H., et al. 2001. VpsR, a Member of the Response Regulators of the Two-Component Regulatory Systems, Is Required for Expression of vps Biosynthesis Genes and EPS(ETr)-Associated Phenotypes inVibrio choleraeO1 El Tor. J. Bacteriol. 183:1716-1726); IrpA gene product fromPyrococcus furiosus(Brinkman, A. B., et al. 2000. An Lrp-like transcriptional regulator from the archaeonPyrococcus furiosusis negatively autoregulated. J. Biol. Chem. 275:38160-38169); manR gene product fromListeria monocytogenes(Dalet, K., et al. 2001. A sigma(54)-dependent PTS permease of the mannose family is responsible for sensitivity ofListeria monocytogenesto mesentericin Y105. Microbiology. 147:3263-3269); msmR gene product fromStreptococcus mutans(Russell, R. R., et al. 1992. A binding protein-dependent transport system inStreptococcus mutansresponsible for multiple sugar metabolism. toxR gene product fromVibrio cholerae(Miller, V. L., and J. J. Mekalanos. 1984. Synthesis of cholera toxin is positively regulated at the transcriptional level by toxR. Proc. Natl. Acad. Sci. 81:3471-3475); padR gene product fromPediococcus pentosaceus(Barthelmebs, L., et al. 2000. Inducible metabolism of phenolic acids inPediococcus pentosaceusis encoded by an autoregulated operon which involves a new class of negative transcriptional regulator. J. Bacteriol. 182:6724-6731); purR (Weng, M., et al. 1995); and xylR gene product fromBacillus megaterium(Rygus, T., et al. 1991. Molecular cloning, structure, promoters and regulatory elements for transcription of theBacillus megateriumencoded regulon for xylose utilization. Arch. Microbiol. 155:535:542).
• II.C.5.d. Bacteriophage and Transposable Elements[0353]
• Regulatory elements, promoters and other expression elements from bacteriophage and transposable elements include without limitation cI gene product from bacteriophage lambda mation and/or segregated minicells (Reichardt, L. F. 1975. Control of bacteriophage lambda repressor synthesis: regulation of the maintenance pathway of the cro and cI products. J. Mol. Biol. 93:289-309); (Love, C. A., et al. 1996. Stable high-copy-number bacteriophage lambda promoter vectors for overproduction of proteins in[0354]Escherichia coli.Gene. 176:49-53); the c2 gene product from bacteriophage P22 (Gough, M., and S. Tokuno. 1975. Further structural and functional analogies between the repressor regions of phages P22 and lambda. Mol. Gen. Genet. 138:71-79); the cro gene from bacteriophage lambda (Reichardt, L. F. 1975. Control of bacteriophage lambda repressor synthesis: regulation of the maintenance pathway of the cro and cI products. J. Mol. Biol. 93:289-309); the ant gene from bacteriophage P22 (Youderian, P. et al. 1982. Sequence determinants of promotor activity. Cell. 30:843-853); the mnt gene from bacteriophage P22 (Gough, M. 1970. Requirement for a functional int product in temperature inductions of prophage P22 ts mnt. J. Virol. 6:320-325; Prell, H. H. 1978. Ant-mediated transactivation of early genes inSalmonella prophageP22 by superinfecting virulent P22 mutants. Mol. Gen. Genet. 164:331-334); the tetR gene product from the TetR family of bacterial regulators or homologues of this gene or gene product found in Tn10 and other members of the bacteriophage, animal virus, Eubacteria, Eucarya or Archaea may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or segregated minicells (Moyed, H. S., and K. P. Bertrand. 1983. Mutations in multicopy Tn10 tet plasmids that confer resistance to inhibitory effects of inducers of tet gene expression. J. Bacteriol. 155:557-564); the mnt gene product from bacteriophage SP6 mation and/or segregated minicells (Mead, D. A., et al. 1985. Single stranded DNA SP6 promoter plasmids for engineering mutant RNAs and proteins: synthesis of a ‘stretched’ preproparathyroid hormone. Nucleic Acids Res. 13:1103-1118); and the mnt gene product from bacteriophage T7 mation and/or segregated minicells (Steen, R., et al. 1986. T7 RNA polymerase directed expression of theEscherichia colirrnB operon. EMBO J. 5:1099-1103).
• II.C.5.e. Use of Site-Specific Recombination in Expression Systems[0355]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include modification of endogenous and/or exogenous regulatory elements responsible for activation and/or repression of proteins to be expressed from chromosomal and/or plasmid expression vectors. By way of non-limiting example, this system may be applied to any of the above regulatory elements/systems. Specifically, each of the above mentioned regulatory systems may be constructed such that the promotor regions are oriented in a direction away from the gene to be expressed, or each of the above mentioned gene(s) to be expressed may be constructed such that the gene(s) to be expressed is oriented in a direction away from the regulatory region promotor. Constructed in this system is a methodology dependent upon site-specific genetic recombination for inversion and induction of the gene of interest (Backman, K., et al. 1984. Use of synchronous site-specific recombination in vivo to regulate gene expression. Bio/Technology 2:1045-1049; Balakrishnan, R., et al. 1994. A gene cassette for adapting[0356]Escherichia colistrains as hosts for att-Int-mediated rearrangement and pL expression vectors. Gene 138:101-104; Hasan, N., and W. Szybalaki. 1987. Control of cloned gene expression by promoter inversion in vivo: construction of improved vectors with a multiple cloning site and the Ptac promotor. Gene 56:145-151; Wulfing, C., and A. Pluckthun. 1993. A versatile and highly repressibleEscherichia coliexpression system based on invertible promoters: expression of a gene encoding a toxic gene product. Gene 136:199-203). These invertible promoters and/or gene regions will allow tight regulation of potentially toxic protein products. By way of non-limiting example, these systems may be derived from bacteriophage lambda, bacteriophage Mu, and/or bacteriophage P22. In any of these potential systems, regulation of the recombinase may be regulated by any of the regulatory systems discussed in section II.C.5 and elsewhere herein.
• II.C.5.e. Use of Copy Number Control Switches[0357]
• A method that can be used to increase the efficiency of gene expression and protein production in minicells involves the modification of endogenous and/or introduction of exogenous genetic expression systems such that the number of copies of a gene encoding a protein to be expressed can be modulated. Copy number control systems comprise elements designed to modulate copy number in a controlled fashion.[0358]
• In an exemplary mode, copy number is controlled to decrease the effects of “leaky” (uninduced) expression of toxic gene products. This allows one to maintain the integrity of a potentially toxic gene product during processes such as cloning, culture maintenance, and periods of growth prior to minicell-induction. That is, decreasing the copy number of a gene is expected to decrease the opportunity for mutations affecting protein expression and/or function to arise. Immediately prior to, during and/or after minicell formation, the copy number may be increased to optimize the gene dosage in minicells as desired.[0359]
• The replication of eubacterial plasmids is regulated by a number of factors, some of which are contained within the plasmid, others of which are located on the chromosome. For reviews, see del Solar, G., et al. 2000. Plasmid copy number control: an ever-growing story. Mol Microbiol. 37:492-500; del Solar, G., et al. 1998. Replication and control of circular bacterial plasmids. Microbiol Mol Biol Rev. 62:434-64; and Filutowicz, M., et al. 1987. DNA and protein interactions in the regulation of plasmid replication. J Cell Sci Suppl. 7:15-31.[0360]
• By way of non-limiting example, the pcnB gene product, the wildtype form of which promotes increased ColE[0361]1 plasmid copy number (Soderbom, F., et al. 1997. Regulation of plasmid R1 replication: PcnB and RNase E expedite the decay of the antisense RNA, CopA. Mol. Microbiol. 26:493-504), is modulated; and/or mutant forms of the pcnB gene are introduced into a cell. In an exemplary cell type that may be used in the methods of the invention, the wildtype pcnB chromosomal gene is replaced with a mutant pcnB80 allele (Lopilato, J., et al. 1986. Mutations in a new chromosomal gene ofEscherichia coliK-12, pcnB, reduce plasmid copy number of pBR322 and its derivatives. Mol. Gen. Genet. 205:285-290). In such cells the copy number of a ColE1-derived plasmid is decreased. The cell may further comprise an expression element comprising an inducible promoter operably linked to an ORF encoding the wild-type pcnB. Because the wild-type pcnB gene is dominant to the mutant pcnB80 gene, and because the wild-type pcnB gene product promotes increased Cole1 plasmid copy number, induction of a wild-type pcnb in the pcnB80 background will increase the plasmid copy number of ColE1-derived plasmids. Such copy number control systems may be expressed from the chromosome and/or plasmid to maintain either low or high plasmid copy number in the absence of induction. Other non-limiting examples of gene and/or gene products that may be employed in copy number control systems for ColE1-based replicons include genes or homologs of genes encoding RNA I, RNA II, rop, RNAse H, enzymes involved in the process of polyadenylation, RNAse E, DNA polymerase I, and DNA polymerase III.
• In the case of IncFII-derived replicons, non-limiting examples of gene and/or gene products that may be employed in copy number control systems to control plasmid copy include genes or homologs of the copA, copB, repA, and repB genes. Copy number control systems may additionally or alternatively include manipulation of repC, trfA, dnaA, dnaB, dnaC, seqA, genes protein Pi, genes encoding HU protein subunits (hupA, hupB) and genes encoding IHF subunits.[0362]
• Other elements may also be included to optimize these plasmid copy number control systems. Such additional elements may include the addition or deletion of iteron nucleic acid sequences (Chattoraj, D. K. 2000. Control of plasmid DNA replication by iterons: no longer paradoxical. Mol. Microbiol. 37:467-476), and modification of chaperone proteins involved in plasmid replication (Konieczny, I., et al. 1997. The replication initiation protein of the broad-host-range plasmid RK2 is activated by the ClpX chaperone. Proc Natl Acad Sci USA 94:14378-14382).[0363]
• II.C.6. Transportation of Inducible and Inhibitory Compounds[0364]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of factors and systems that modulate the transport of compounds, including but not limited to inducers and/or inhibitors of expression elements that control expression of a gene in a parent cell prior to minicell formation and/or in segregated minicells. Such manipulations may result in increased or decreased production, and/or changes in the intramolecular and intermolecular functions, of a protein in a minicell or its parent cell. The techniques may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells.[0365]
• II.C.6.a.[0366]Escherichia coliGenes
• By way of non-limiting example, manipulation of the abpS gene or gene product from[0367]E. coli,or homologs of this gene or gene product found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and/or organelles (e.g., mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells (Celis, R. T. 1982. Mapping of two loci affecting the synthesis and structure of a periplasmic protein involved in arginine and ornithine transport inEscherichia coliK-12. J. Bacteriol. 151(3):1314-9).
• In addition to abpS, other exemplary[0368]E. coligenes encoding factors involved in the transport of inducers, inhibitors and other compounds include, but are not limited to, araE (Khlebnikov, A., et al. 2001. Homogeneous expression of the P(BAD) promoter inEscherichia coliby constitutive expression of the low-affinity high-capacity AraE transporter. Microbiology. 147(Pt 12):3241-7); araG (Kehres, D. G., and Hogg, R. W. 1992.Escherichia coliK12 arabinose-binding protein mutants with altered transport properties. Protein Sci. 1(12):1652-60); araH (Id.); argP (Celis, R. T. 1999. Repression and activation of arginine transport genes inEscherichia coliK 12 by the ArgP protein. J. Mol Biol. 17;294(5):1087-95); aroT (aroR, trpR) (Edwards, R. M., and Yudkin, M. D. 1982. Location of the gene for the low-affinity tryptophan-specific permease ofEscherichia coli.Biochem. J. 204(2):617-9); artI (Wissenbach, U., et al. 1995. A third periplasmic transport system for L-arginine inEscherichia coli:molecular characterization of the artPIQMJ genes, arginine binding and transport. Mol. Microbiol. 17(4):675-86); artJ (Id.); artM (Id.); artP (Id.); artQ (Id.); bioP (bir, birB) (Campbell, A., et al. Biotin regulatory (bir) mutations ofEscherichia coli.1980. J. Bacteriol. 142(3):1025-8); brnQ (hrbA) (Yamato, I., and Anraku, Y. 1980. Genetic and biochemical studies of transport systems for branched-chain amino acids inEscherichia coliK-12: isolation and properties of mutants defective in leucine-repressible transport activities. J. Bacteriol. 144(1):36-44); brnR (Id.); brnS (Id.); brnT (Id.); btuC (Friedrich, M. J., et al. 1986. Nucleotide sequence of the btuCED genes involved in vitamin B12 transport inEscherichia coliand homology with components of periplasmic-binding-protein-dependent transport systems. J. Bacteriol. 167(3):928-34); btuD (Id.) (Friedrich, M. J., et al. 1986. Nucleotide sequence of the btuCED genes involved in vitamin B12 transport inEscherichia coliand homology with components of periplasmic-binding-protein-dependent transport systems. J. Bacteriol. 167(3):928-34); caiT (Eichler, K. 1994. Molecular characterization of the cai operon necessary for carnitine metabolism inEscherichia coli.Mol. Microbiol. 13(5):775-86); celA (Parker, L. L., and Hall, B. G. 1990. Characterization and nucleotide sequence of the cryptic cel operon ofEscherichia coliK12. Genetics. 124(3):455-71); celB (Id.); celC (Id.); citA (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); citB (Id.); codB (Danielsen, S., et al. 1992. Characterization of theEscherichia colicodBA operon encoding cytosine permease and cytosine deaminase. Mol. Microbiol. 6(10):1335-44); cysA (Karbonowska, H., et al. 1977. Sulphate permease ofEscherichia coliK12. Acta. Biochim. Pol. 24(4):329-34); cysU (cysT) (Sirko, A., et al. 1995. Sulfate and thiosulfate transport inEscherichia coliK-12: evidence for a functional overlapping of sulfate- and thiosulfate-binding proteins. J. Bacteriol. 177(14):4134-6); cysW (Id.); dctA (Lo, T. C., and Bewick, M. A. 1978. The molecular mechanisms of dicarboxylic acid transport inEscherichia coliK12. The role and orientation of the two membrane-bound dicarboxylate binding proteins. J. Biol. Chem. 10;253(21):7826-31); dctB (Id.); dcuA (genA) (Six, S., et al. 1994.Escherichia colipossesses two homologous anaerobic C4-dicarboxylate membrane transporters (DcuA and DcuB) distinct from the aerobic dicarboxylate transport system (Dct). J. Bacteriol. 176(21):6470-8); dcuB (genF) (.); dgoT (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); exuT (Nemoz, G., et al. 1976. Physiological and genetic regulation of the aldohexuronate transport system inEscherichia coli.J. Bacteriol. 127(2):706-18); fepD (Ozenberger, B. A., et al. 1987. Genetic organization of multiple fep genes encoding ferric enterobactin transport functions inEscherichia coli.J. Bacteriol. 169(8):3638-46); fepG (Chenault, S. S., and Earhart, C. F. 1991. Organization of genes encoding membrane proteins of theEscherichia coliferrienterobactin permease. Mol. Microbiol. 5(6): 1405-13); fucP (prd) (Chen, Y. M. 1987. The organization of the fuc regulon specifying L-fucose dissimilation inEscherichia coliK12 as determined by gene cloning. Mol. Gen. Genet. 210(2):331-7); glnP (Masters, P. S., and Hong, J. S. 1981. Genetics of the glutamine transport system inEscherichia coli.J. Bacteriol. 147(3):805-19); glnQ (Nohno, T. 1986. Cloning and complete nucleotide sequence of theEscherichia coliglutamine permease operon (glnHPQ). Mol. Gen. Genet. 205(2):260-9); glnR (Masters, P. S., and Hong, J. S. 1981. Genetics of the glutamine transport system inEscherichia coli.J. Bacteriol. 147(3):805-19); glpT (Boos, W., et al. 1977. Purification and properties of a periplasmic protein related to sn-glycerol-3-phosphate transport inEscherichia coli.Eur. J. Biochem. 72(3):571-81); gltP (Deguchi, Y., et al. 1989. Molecular cloning of gltS and gltP, which encode glutamate carriers ofEscherichia coli.B. J. Bacteriol. 171(3):1314-9); gltS (Id.); gntR (Bachi, B., and Kornberg, H. L. 1975. Genes involved in the uptake and catabolism of gluconate byEscherichia coli.J. Gen. Microbiol. 90(2):321-35); gntS (Id.); gntT (gntM, usgA) (Id.); gntU (Tong, S. 1996. Cloning and molecular genetic characterization of theEscherichia coligntR, gntK, and gntU genes of GntI, the main system for gluconate metabolism. J. Bacteriol. 178(11):3260-9); hisM (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); hisP (Id.); hisQ (Id.); livG (hrbB, hrbC, hrbD) (Landick, R., et al. 1980. Regulation of high-affinity leucine transport inEscherichia coli.J. Supramol. Struct. 14(4):527-37); livH (hrbB, hrbC, hrbD) (Id.); livJ (hrbB, hrbC, hrbD) (Id.); livK (hrbB, hrbC, hrbD) (Id.); lldP (Id.); lilP (lctP) (Dong, J. M., et al. 1993. Three overlapping lct genes involved in L-lactate utilization byEscherichia coli.J. Bacteriol. 175(20):6671-8); lysP (cadR) (Steffes, C., et al. 1992. The lysP gene encodes the lysine-specific permease. J. Bacteriol. 174(10):3242-9); malF (malB) (Bavoil, P., et al. 1980. Identification of a cytoplasmic membrane-associated component of the maltose transport system ofEscherichia coli.J. Biol. Chem. 255(18):8366-9); malG (malB) (Dassa, E., and Hofnung, M. 1985. Sequence of gene maIG inE. coliK12: homologies between integral membrane components from binding protein-dependent transport systems. EMBO J. 4(9):2287-93); malK (malB) (Id.); mglC (PMG, mglP) (Harayama, S. 1983. Characterization of the mgl operon ofEscherichia coliby transposon mutagenesis and molecular cloning. J. Bacteriol. 153(1):408-15); nanT (Vimr, E. R., and Troy, F. A. 1985. Identification of an inducible catabolic system for sialic acids (nan) inEscherichia coli.J. Bacteriol. 164(2):845-53); nupC (cru) (Craig, J. E., et al. 1994. Cloning of the nupC gene ofEscherichia coliencoding a nucleoside transport system, and identification of an adjacent insertion element, IS 186. Mol. Microbiol. 11(6): 1159-68); nupG (Westh Hansen, S. E., et al. 1987. Studies on the sequence and structure of theEscherichia coliK-12 nupG gene, encoding a nucleoside-transport system. Eur. J. Biochem. 168(2):385-91); panF (Vallari, D. S., and Rock, C. O. 1985. Isolation and characterization ofEscherichia colipantothenate permease (panF) mutants. J. Bacteriol. 164(1): 136-42); potA (Kashiwagi, K., et al. 1993. Functions of potA and potD proteins in spermidine-preferential uptake system inEscherichia coli.J. Biol. Chem. 268(26):19358-63); potG (Pistocchi, R., et al. 1993. Characteristics of the operon for a putrescine transport system that maps at 19 minutes on theEscherichia colichromosome. J. Biol. Chem. 268(1):146-52); potH (Id.); potI (Id.); proP (Wood, J. M., and Zadworny, D. 1980. Amplification of the put genes and identification of the put gene products inEscherichia coliK12. Can. J. Biochem. 58(10):787-96); proT (Id.); proV (proU) (Faatz, E., et al. 1988. Cloned structural genes for the osmotically regulated binding-protein-dependent glycine betaine transport system (ProU) ofEscherichia coliK-12. Mol. Microbiol. 2(2):265-79); proW (proU) (Id.); proX (proU) (Id.); pstA (R2pho, phoR2b, phoT) (Amemura, M., et al. 1985. Nucleotide sequence of the genes involved in phosphate transport and regulation of the phosphate regulon inEscherichia coli.J. Mol. Biol. 184(2):241-50); pstB (phoT) (Id.); pstC (phoW) (Rao, N. N., and Torriani, A. 1990. Molecular aspects of phosphate transport inEscherichia coli.Mol. Microbiol. 4(7):1083-90); pstS (R2pho, nmpA, phoR2a, phoS) (Makino, K., et al. 1988. Regulation of the phosphate regulon ofEscherichia coli.Activation of pstS transcription by PhoB protein in vitro. J. Mol. Biol. 203(1):85-95); purP (Burton, K. 1994. Adenine transport inEscherichia coli.Proc. R. Soc. Lond. B. Biol. Sci. 255(1343):153-7); putP (Stalmach, M. E., et al. 1983. Two proline porters inEscherichia coli K-12. J. Bacteriol. 156(2):481-6); rbsA (rbsP, rbsT) (Iida, A., et al. 1984. Molecular cloning and characterization of genes required for ribose transport and utilization inEscherichia coliK-12. J. Bacteriol. 158(2):674-82); rbsC (rbsP, rbsT) (Id.); rbsD (rbsP) (Id.); rhaT (Baldoma, L., et al. 1990. Cloning, mapping and gene product identification of rhaT fromEscherichia coliK12. FEMS Microbiol. Lett. 60(1-2):103-7); sdaC (Shao, Z., et al. 1994. Sequencing and characterization of the sdaC gene and identification of the sdaCB operon inEscherichia coliK12. Eur. J. Biochem. 222(3):901-7); tnaB (trpP) (Sarsero, J. P., et al. 1991. A new family of integral membrane proteins involved in transport of aromatic amino acids inEscherichia coli.J. Bacteriol. 173(10):3231-4); tyrR (Whipp, M. J., and Pittard, A. J. 1977. Regulation of aromatic amino acid transport systems inEscherichia coliK-12. J. Bacteriol. 132(2):453-61); ugpC (Schweizer, H., and Boos, W. 1984. Characterization of the ugp region containing the genes for the phoB dependent sn-glycerol-3-phosphate transport system ofEscherichia coli.Mol. Gen. Genet. 197(1):161-8); uhpT (Weston, L. A., and Kadner, R. J. 1987. Identification of uhp polypeptides and evidence for their role in exogenous induction of the sugar phosphate transport system ofEscherichia coliK-12. J. Bacteriol. 169(8):3546-55); and xylF (xylT) (Sumiya, M., et al. 1995. Molecular genetics of a receptor protein for D-xylose, encoded by the gene xylF, inEscherichia coli.Receptors Channels. 3(2): 117-28).
• II.C.6.b.[0369]Bacillus subtilisGenes
• By way of non-limiting example, manipulation of the aapA gene or gene product from[0370]B. subtilis,or homologs of this gene or gene product found in other members of the Prokaryotes, Eukaryotes, Archaebacteria and/or organelles (e.g., mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.).
• In addition to aapA, other exemplary[0371]B. subtilisgenes encoding factors involved in the transport of inducers, inhibitors and other compounds include, but are not limited to, amyC (Sekiguchi, J., et al. 1975. Genes affecting the productivity of alpha-amylase inBacillus subtilis.J. Bacteriol. 121(2):688-94); amyD (Id.); araE (Sa-Nogueira, I., and Mota, L. J. 1997. Negative regulation of L-arabinose metabolism inBacillus subtilis:characterization of the araR (araC) gene. J. Bacteriol. 179(5):1598-608); araN (Sa-Nogueira, I., et al. 1997. TheBacillus subtilisL-arabinose (ara) operon: nucleotide sequence, genetic organization and expression. Microbiology. 143 (Pt 3):957-69); araP (Id.); araQ (Id.); csbC (Akbar, S., et al. 1999. Two genes fromBacillus subtilisunder the sole control of the general stress transcription factor sigmaB. Microbiology. 145 (Pt 5):1069-78); cysP (Mansilla, M. C., and de Mendoza, D. 2000. TheBacillus subtiliscysP gene encodes a novel sulphate permease related to the inorganic phosphate transporter (Pit) family. Microbiology. 146 (Pt 4):815-21); dctB (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); exuT (Rivolta, C., et al. 1998. A 35.7 kb DNA fragment from theBacillus subtilischromosome containing a putative 12.3 kb operon involved in hexuronate catabolism and a perfectly symmetrical hypothetical catabolite-responsive element. Microbiology. 144 (Pt 4):877-84); gabP (Ferson, A. E., et al. 1996. Expression of theBacillus subtilisgabP gene is regulated independently in response to nitrogen and amino acid availability. Mol. Microbiol. 22(4):693-701); gamP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); glcP (Paulsen, I. T., et al. 1998. Characterization of glucose-specific catabolite repression-resistant mutants ofBacillus subtilis:identification of a novel hexose:H+symporter. J. Bacteriol. 180(3):498-504); glcU (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); glnH (Id.); glnM (Id); glnP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); glnQ (Id.); glpT (Nilsson, R. P., et al. 1994. The glpT and glpQ genes of the glycerol regulon inBacillus subtilis.Microbiology. 140 (Pt 4):723-30); gltP (Tolner, B., et al. 1995. Characterization of the proton/glutamate symport protein ofBacillus subtilisand its functional expression inEscherichia coli.J. Bacteriol. 177(10):2863-9); gltT (Tolner, B., et al. 1995. Characterization of the proton/glutamate symport protein ofBacillus subtilisand its functional expression inEscherichia coli.J. Bacteriol. 177(10):2863-9); gntP (Reizer, A., et al. Analysis of the gluconate (gnt) operon ofBacillus subtilis.Mol. Microbiol. 5(5): 1081-9); gutP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); hutM (Oda, M., et al. 1988. Cloning and nucleotide sequences of histidase and regulatory genes in theBacillus subtilishut operon and positive regulation of the operon. J. Bacteriol. 170(7):3199-205); iolF (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); kdgT (Pujic, P., et al. 1998. The kdgRKAT operon ofBacillus subtilis:detection of the transcript and regulation by the kdgR and ccpA genes. Microbiology. 144 (Pt 11):3111-8); lctP (Cruz, Ramos H., et al. 2000. Fermentative metabolism ofBacillus subtilis:physiology and regulation of gene expression. J. Bacteriol. 182(11):3072-80); maeN (Ito, M., et al. 2000. Effects of nonpolar mutations in each of the sevenBacillus subtilismrp genes suggest complex interactions among the gene products in support of Na(+) and alkali but not cholate resistance. J. Bacteriol. 182(20):5663-70); malP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); manP (Id.); mleN (Id.); nasA (Ogawa, K., et al. 1995. The nasB operon and nasA gene are required for nitrate/nitrite assimilation inBacillus subtilis.J. Bacteriol. 177(5): 1409-13); nupC (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); opuAB (Kempf, B., et al. 1997. Lipoprotein from the osmoregulated ABC transport system OpuA ofBacillus subtilis:purification of the glycine betaine binding protein and characterization of a functional lipidless mutant. J. Bacteriol. 179(20):6213-20); opuBA (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); pbuG (Saxild, H. H., et al. 2001. Definition of theBacillus subtilisPurR operator using genetic and bioinformatic tools and expansion of the PurR regulon with glyA, guaC, pbuG, xpt-pbuX, yqhZ-folD, and pbuO. J. Bacteriol. 183(21):6175-83); pbuX (Saxild, H. H., et al. 2001. Definition of theBacillus subtilisPurR operator using genetic and bioinformatic tools and expansion of the PurR regulon with glyA, guaC, pbuG, xpt-pbuX, yqhZ-folD, and pbuO. J. Bacteriol. 183(21):6175-83); pstC (Takemaru, K., et al. 1996. ABacillus subtilisgene cluster similar to theEscherichia coliphosphate-specific transport (pst) operon: evidence for a tandemly arranged pstB gene. Microbiology. 142 (Pt 8):2017-20); pstS (Qi, Y., et al. 1997. The pst operon ofBacillus subtilishas a phosphate-regulated promoter and is involved in phosphate transport but not in regulation of the pho regulon. J. Bacteriol. 179(8):2534-9); pucJ (Schultz, A. C., et al. 2001. Functional analysis of 14 genes that constitute the purine catabolic pathway inBacillus subtilisand evidence for a novel regulon controlled by the PucR transcription activator. J. Bacteriol. 183(11):3293-302); pucK (Schultz, A. C., et al. 2001. Functional analysis of 14 genes that constitute the purine catabolic pathway inBacillus subtilisand evidence for a novel regulon controlled by the PucR transcription activator. J. Bacteriol. 183(11):3293-302); pyrP (Turner, R. J., et al. 1994. Regulation of theBacillus subtilispyrimidine biosynthetic (pyr) gene cluster by an autogenous transcriptional attenuation mechanism. J. Bacteriol. 176(12):3708-22); rbsB (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); rbsC (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); rbsD (Id.); rocC (Gardan, R., et al. 1995. Expression of the rocDEF operon involved in arginine catabolism inBacillus subtilis.J. Mol. Biol. 23;249(5):843-56); rocE (Gardan, R., et al. 1995. Expression of the rocDEF operon involved in arginine catabolism inBacillus subtilis.J. Mol. Biol. 23;249(5):843-56); ssuA (Coppee, J. Y., et al. 2001. Sulfur-limitation-regulated proteins inBacillus subtilis:a two-dimensional gel electrophoresis study. Microbiology. 147(Pt 6):1631-40); ssuB (van der Ploeg, J. R., et al. 1998.Bacillus subtilisgenes for the utilization of sulfur from aliphatic sulfonates. Microbiology. 144 (Pt 9):2555-61); ssuC (van der Ploeg, J. R., et al. 1998.Bacillus subtilisgenes for the utilization of sulfur from aliphatic sulfonates. Microbiology. 144 (Pt 9):2555-61); treP (Yamamoto, H., et al. 1996. Cloning and sequencing of a 40.6 kb segment in the 73 degrees-76 degrees region of theBacillus subtilischromosome containing genes for trehalose metabolism and acetoin utilization. Microbiology. 142 (Pt 11):3057-65); xynP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); ybaR (Id.); ybgF (Id.); ybgH (Id.); ycbE (Id.); ycgO (Id..); yckI (Id.); yckJ (Id.); yckK (Id.); ydgF (Id.); yecA (Borriss, R., et al. 1996. The 52 degrees-55 degrees segment of theBacillus subtilischromosome: a region devoted to purine uptake and metabolism, and containing the genes cotA, gabP and guaA and the pur gene cluster within a 34960 bp nucleotide sequence. Microbiology. 142 (Pt 11):3027-31); yesP (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); yesQ (Id.): yflS (Id.); yhcL (Id.); yhjB (Id.); yjkB (Id.); ykbA (Id.); yoaB (Id.); yocN (Id.); yodF (Id.); yojA (Id.); yqiY (Id.); ytlD (Id.); ytlP (Id.); ytmL (Id.); ytmM (Id.); ytnA (Id.); yurM (Id.); yurN (Id.); yvbW (Id.); yvdH (Id.); yvdI (Id.); yveA (Pereira, Y., et al. 2001. The yveB gene, Encoding endolevanase LevB, is part of the sacB-yveB-yveA levansucrase tricistronic operon inBacillus subtilis.Microbiology. 147(Pt 12):3413-9); yvfH (Sohenshein, A. L., J. A. Hoch, and R. Losick (eds.) 2002.Bacillus subtilisand its closest relatives: from genes to cells. American Society for Microbiology, Washington D.C.); yvfL (Id.); yvfM (Id.); yvgM (Id.); yvrO (Id.); yvsH (Id.); ywbF (Id.); ywcJ (Id.); ywoD (Id.); ywoE (Id.); yxeN (Id.); and yxeR (Id.).
• II.C.7. Catabolite Repression[0372]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of factors and systems involved in the synthesis, degradation or transport of catabolites that modulate the genetic expression of a preselected protein. Such manipulations may result in increased or decreased production, and/or changes in the intramolecular and intermolecular functions, of a protein in a minicell or its parent cell; in the latter instance, the protein may be one that is desirably retained in segregated minicells.[0373]
• By way of non-limiting example, it is known in the art to use promoters from the trp, cst-1, and llp operons of[0374]E. coli,which are induced by, respectively, reduced tryptophan levels, glucose starvation, and lactose. Manipulation of the catabolites tryptophan, glucose and lactose, respectively, will influence the degree of expression of genes operably linked to these promoters. (Makrides, Savvas C., Strategies for Achieving High-Level Expression of Genes inEscherichia coli.Microbiological Reviews. 1996. 60:512-538.)
• As another non-limiting example, expression elements from the[0375]E. coliL-arabinose (ara) operon are used in expression systems. AraC is a protein that acts as a repressor of ara genes in the absence of arabinose, and also as an activator of ara genes when arabinose is present. Induction of ara genes also involves cAMP, which modulates the activity of CRP (cAMP receptor protein), which in turn is required for full induction of ara genes (Schleif, Robert, Regulation of the L-arabinose operon ofEscherichia coli.2000. TIG 16:559-564. Thus, maximum expression from an ara-based expression system is achieved by adding cAMP and arabinose to host cells, and optimizing the expression of CRP in hostcells.
• As one example, manipulation of the acpS gene or gene product of[0376]E. coli(Pollacco M. L., and J. E. Cronan Jr. 1981. A mutant ofEscherichia coliconditionally defective in the synthesis of holo-[acyl carrier protein]. J. Biol. Chem. 256:5750-5754); or homologs of this gene or its gene product found in other prokaryotes, eukaryotes, archaebacteria or organelles (mitochondria, chloroplasts, plastids and the like) may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or in segregated minicells.
• In addition to acpS, other exemplary[0377]E. coligenes include the b2383 gene (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella thyphimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein. b2387 gene; the celA gene (Parker L. L., and B. G. Hall. 1990. Characterization and nucleotide sequence of the cryptic cel operon ofEscherichia coliK12. Genetics. 124:455-471); the celB gene (Cole S. T., and B. Saint-Joanis, and A. P. Pugsley. 1985. Molecular characterisation of the colicin E2 operon and identification of its products. Mol Gen Genet. 198:465-472); the celC gene (Parker L. L., and B. G. Hall. 1990. Characterization and nucleotide sequence of the cryptic cel operon ofEscherichia coliK12. Genetics. 124:455-471); the cmtB gene (Ezhova N. M., Zaikina, N. A, Shataeva, L. K., Dubinina, N. I., Ovechkina, T. P. and J. V. Kopylova. [Sorption properties of carboxyl cation exchangers with a bacteriostatic effect]. 1980. Prikl Bioikhim Mikrobiol. 16:395-398); the creB gene (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium:Cellular and Molecular Biology, 2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein; the creC gene (Wanner B. L. Gene regulation by phosphate in enteric bacteria. 1993. J Cell Biochem. 51:47-54); the crp gene (Sabourn D., and J. Beckwith. Deletion of theEscherichia colicrp gene. 1975. J Bacteriology. 122:338-340); the crr (gsr, iex, tgs, treD) gene (Jones-Mortimer M. C., and H. L. Kornberg, and r. Maltby, and P. D. Watts. Role of the crr-gene in glucose uptake byEscherichia coli.1977. FEBS Lett. 74:17-19); the cya gene (Bachi B., and H. L. Kornberg. Utilization of gluconate byEscherichia coli.A role of adenosine 3′:5′-cyclic monophosphate in the induction of gluconate catabolism. 1975. Biochem J. 150:123-128); the fruA gene (Prior T. I., and H. L. Kornberg. Nucleotide sequence of fruA, the gene specifying enzyme Iifru of the phosphoenopyruvate-dependent sugar phosphotranssferase system inEscherichia coliK12. 1988. J Gen Microbiol. 134:2757-2768); the fuB gene (Bol'shakova T. N. and R. S. Erlagaeva, and Dobrynina Oiu, and V. N. Gershanovich. [Mutation fruB in the fructose regulon affeting beta-galactosidase synthesis and adenylate cyclase activity ofE. coliK12]. 1988. Mol Gen Mikrobiol virusol. 3:33-39); the fruR gene (Jahreis K., and P. W. Postma, and J. W. Lengeler. Nucleotide sequence of the ilvH-frR gene region ofEscherichia coliK12 andSalmonella typhimuriumLT2. 1991. Mol Gen Genet. 226:332-336); the frvA gene (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9, ” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); the ftwB gene (Id.); the frvD gene (Id.); the gatB gene (Nobelmann B., and J. W. Lengeler. Molecular analysis of the gat genes fromEscherichia coliand of their roles in galactitol transport and metabolism. 1996. J Bacteriol. 178:6790-6795); the gatC gene (Id.); the malX gene (Reidel J., W. Boos. The malX malY operon ofEscherichia coliencodes a novel enzyme II of the photophotransferase system recognizing glucose and maltose and an enzyme abolishing the endogenous induction of the maltose system. 1991. J Bacteriol. 173:4862-4876); the manX (gptB, mpt, ptsL, ptsM, ptsX, manIII) gene (Plumbridge J., and A. Kolb. CAP and Nag repressor binding to the regulatory regions of the nagE-B and manX genes ofEscherichia coli.1991. J Mol Biol. 217:661-679); the manY (pel, ptsM, ptsP, manPII) gene (Henderson P. J., and R. A. Giddens, and M. C. Jones-Mortimer. Transport of galactose, glucose and their molecular analogues byEscherichia coliK12. 1977. Biochem J. 162:309-320); the manZ (gptB, mpt, ptsM, ptsX) gene (Williams N., and D. K. Fox, and C. Shea and S. Roseman. Pel, the protein that permits lambda DNA penetration ofEscherichia coli,is encoded by a gene in ptsM and is required for mannose utilization by the phosphotransferase system. 1986. Proc Natl Acad Sci USA. 83:8934-8938); the mtlA gene (Lengeler J. Mutations affecting transport of the hexitols D-mannitol, D-glucitol, and galactitol inEscherichia coliK-12: isolation and mapping. 1975. J Bacteriol. 124:26-38.); the nagE (pstN) gene (Rogers M. J., and T. Ohgi, and J. Plumbridge, and D. Soll. Nucleotide sequences of theEscherichia colinagE and nagB genes: the structural genes for the N-acetylglucosamine transport protein of the bacterial phosphoenolpyruvate: sugar phosphotransferase system and for glucosamine-6-phosphate deaminase. 1988. Gene. 62:197-207); the pstA gene (Cox G. B., H. Rosenberg, and J. A. Downie, and S. Silver. Genetic analysis of mutants affected in the Pst inorganic phosphate transport system. 1981. J Bacteriol. 148:1-9); the pstB (gutB) gene (Id.); the pstG gene (Cox G. B., H. Rosenberg, and J. A. Downie, and S. Silver. Genetic analysis of mutants affected in the Pst inorganic phosphate transport system. 1981. J Bacteriol. 148:1-9); the pstH gene (Id.); the pstI gene (Id.); the pstN gene (Id.); the pstO gene (Id.); the ptxA (yifU) gene (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); the sgcA (yjhL) gene (Id.); the sgcC (yjhN) gene (Id.); the treB gene (Boos W., U. Ehmann, H. Forkl, W. Klein, M. Rimmele, and P. Postma. Trehalose transport and metabolism inEscherichia coli.1990. J. Bacteriol. 172:3450-3461); the usg gene (Arps P. J., and M. E. Winkler M E. Structural analysis of theEscherichia coliK-12 hisT operon by using a kanamycin resistance cassette. 1987. J Bacteriol. 169:1061-1070); the wcaD gene (Mao Y., and M. P. Doyle, and J. Chen. Insertion mutagenisis of wca reduces acide and heat tolerance of enterohemorrhagicEscherichia coliO157:H7. 2001. J Bacteriol. 183:3811-3815); the yadI gene (Berlyn et al., “Linkage Map ofEscherichia coliK-12, Edition 9,” Chapter 109 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1715-1902, and references cited therein); and the ycgC gene (Gutknecht R., and R. Beutler, and L. F. Garcia-Alles, and U. Baumann, and B. Erni. The dihydroxyacetone kinase ofEscherichia coliutilizes a phosphoprotein instead of ATP as phosphoryl donor. 2001. EMBO J. 20:2480-2486).
• II.C.8. General Deletions and Modifications[0378]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in minicells. By way of non-limiting example, these techniques may include modification or deletion of endogenous gene(s) from which their respective gene product decreases the induction and expression efficiency of a desired protein in the parent cell prior to minicell formation and/or the segregated minicell. By way of non-limiting example, these protein components may be the enzymes that degrade chemical inducers of expression, proteins that have a dominant negative affect upon a positive regulatory elements, proteins that have proteolytic activity against the protein to be expressed, proteins that have a negative affect against a chaperone that is required for proper activity of the expressed protein, and/or this protein may have a positive effect upon a protein that either degrades or prevents the proper function of the expressed protein. These gene products that require deletion or modification for optimal protein expression and/or function may also be antisense nucleic acids that have a negative affect upon gene expression.[0379]
• II.C.9. Cytoplasmic Redox State[0380]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and functional protein production in minicells. By way of non-limiting example, these techniques may include modification of endogenous and/or exogenous protein components that alter the redox state of the parental cell cytoplasm prior to minicell formation and/or the segregated minicell cytoplasm. By way of non-limiting example, this protein component may be the product of the trxA, grx, dsbA, dsbB, and/or dsbc genes from[0381]E. colior homologs of this gene or gene product found in other members of the Eubacteria, Eucarya or Archae (Mark et al., Genetic mapping of trxA, a gene affecting thioredoxin inEscherichia coliK12, Mol Gen Genet. 155:145-152, 1977; (Russel et al., Thioredoxin or glutaredoxin inEscherichia coliis essential for sulfate reduction but not for deoxyribonucleotide synthesis, J Bacteriol. 172:1923-1929, 1990); Akiyama et al., In vitro catalysis of oxidative folding of disulfide-bonded proteins by theEscherichia colidsbA (ppfA) gene product, J Biol Chem. 267:22440-22445, 1992); (Whitney et al., The DsbA-DsbB system affects the formation of disulfide bonds in periplasmic but not in intramembraneous protein domains, FEBS Lett. 332:49-51, 1993); (Shevchik et al., Characterization of DsbC, a periplasmic protein of Erwinia chrysanthemi andEscherichia coliwith disulfide isomerase activity, EMB J. 13:2007-2012, 1994). These applications may, but are not limited to increased or decreased production, increased or decreased intramolecular TrxA activity, increased or decreased physiological function of the above-mentioned gene products. By way of non-limiting example, increased production of gene product (gene expression) may occur through increased gene dosage (increased copy number of a given gene under the control of the native or artificial promotor where this gene may be on a plasmid or in more than one copy on the chromosome), modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/inhancers, or relevant antisense nucleic acid or nucleic acid analog, cloning on a plasmid under the control of the native or artificial promotor, and increased or decreased production of native or artificial promotor regulatory elements) controlling production of the gene. By way of non-limiting example, decreased gene expression production may occur through modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/inhancers, or relevant antisense nucleic acid or nucleic acid analog, through cloning on a plasmid under the control of the native regulatory region containing mutations or an artificial promotor, either or both of which resulting in decrease gene expression, and through increased or decreased production of native or artificial promotor regulatory element(s) controlling gene expression. By definition, intramolecular activity refers to the enzymatic function, structure-dependent function, e.g. the capacity off a gene product to interact in a protein-protein, protein-nucleic acid, or protein-lipid complex, and/or carrier function, e.g. the capacity to bind, either covalently or non-covalently small organic or inorganic molecules, protein(s) carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s). By way of non-limiting example, alteration of intramolecular activity may be accomplished by mutation of the gene, in vivo or in vitro chemical modification of the gene product, inhibitor molecules against the function of the gene product, e.g. competitive, non-competitive, or uncompetitive enzymatic inhibitors, inhibitors that prevent protein-protein, protein-nucleic acid, or protein-lipid interactions, e.g. expression or introduction of dominant-negative or dominant-positive or other protein fragment(s), or other carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s) that may act directly or allosterically upon the gene product, and/or modification of protein, carbohydrate, fatty acid, lipid, or nucleic acid moieties that modify the gene or gene product to create the functional protein. By definition, physiological function refers to the effects resulting from an intramolecular interaction between the gene product and other protein, carbohydrate, fatty acid, lipid, nucleic acid, or other molecule(s) in or on the cell or the action of a product or products resulting from such an interaction.
• By way of non-limiting example, physiological function may be the act or result of intermolecular phosphorylation, biotinylation, methylation, acylation, glycosylation, and/or other signaling event; this function may be the result of protein-protein, protein-nucleic acid, or protein-lipid interaction resulting in a functional moiety; this function may be to interact with the membrane to recruit other molecules to this compartment of the cell; this function may be to regulate the transcription and/or translation of trxA, other protein, or nucleic acid; and this function may be to stimulate the function of another process that is not yet described or understood.[0382]
• II. C.10. Transcriptional Terminators[0383]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in parental cell cytoplasm prior to minicell formation and/or the segregated minicell cytoplasm. By way of non-limiting example, these techniques may include modification of terminator regions of DNA templates or RNA transcripts so that transcription and/or translation of these nucleic acid regions will terminate at greater efficiency. By way of non-limiting example, these techniques may include stem-loop structures, consecutive translational terminators, polyadenylation sequences, or increasing the efficiency of rho-dependent termination. Stem loop structures may include, but are not limited to, inverted repeats containing any combination of deoxyribonucleic acid or ribonucleic acid molecule, more than one such inverted repeat, or variable inverted repeats such that the rate of transcriptional/translational termination may be moderated dependent on nucleic acid and/or amino acid concentration, e.g. the mechanism of regulatory attenuation (Oxdender et al., Attenuation in the[0384]Escherichia colitryptophan operon: role of RNA secondary structure involving the tryptophan codon region, Proc. Natl. Acad. Sci. 76:5524-5528, 1979). See also, Yager and von Hippel, “Transcript Elongation and Termination in e. Col. And Landick and Yanofsky, “Transcriptional Attenuation,” Chapters 76 and 77, respectively in:Escherichia ColiandSalmonella Typhimurium: Cellular and Molecular Biology,Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987,Volume 1, pages 1241-1275 and 1276-1301, respectively, and references cited therein.
• II. C.11. Ribosomal Targeting[0385]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in parental cell cytoplasm prior to minicell formation and/or the segregated minicell cytoplasm. By way of non-limiting example, these techniques may include modifications of endogenous and/or exogenous ribosomal components such that ribosomes enter the minicell segregates with higher efficiency. By way of non-limiting example, these techniques may include increasing the copy number of ribosomal binding sites on plasmid or like structure to recruit more ribosomal components or increase the synthesis of ribosomal subunits prior to segregation (Mawn et al., Depletion of free 30S ribosomal subunits in[0386]Escherichia coliby expression of RNA containing Shine-Dalgarno-like sequences, J. Bacteriol. 184:494-502, 2002). This construct may also include the use of plasmid expressed translation initiation factors to assist ribosomal segregation (Celano et al., Interaction ofEscherichia colitranslation-initiation factor IF-1 with ribosomes, Eur. J. Biochem. 178:351-355 1988). See also Hoopes and McClure, “Strategies in Regulation of Transcription Initiation,” Chapter 75 in:Escherichia Coli and Salmonella Typhimurium: Cellular and Molecular Biology,Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987, Volume 2, pages 1231-1240, and references cited therein.
• II. C.12. Proteases[0387]
• Included in the design of the invention are techniques that increase the efficiency of gene[0388]
• expression and protein production in minicells. By way of non-limiting example, these techniques may include utilization and/or modification of endogenous and/or exogenous proteases. Such manipulations may result in increased or decreased production, and/or changes in the intramolecular and intermolecular functions, of a protein in a minicell or its parent cell; in the latter instance, the protein may be one that is desirably retained in segregated minicells.[0389]
• The production or activity of a desired protein gene product may be increased by decreasing the level and/or activity of a protease that acts upon the desired protein. The production or activity of a desired protein gene product may be increased by increasing the level and/or activity of a protease that acts upon a protein that inhibits the production or function of the desired protein.[0390]
• The production or activity of a desired nucleic acid gene product may be increased be increasing the level and/or activity of a protease that acts upon a protein that that inhibits the production or function of the nucleic acid gene product. The production or activity of a desired nucleic acid gene product may be increased by decreasing the level and/or activity of a protease that acts upon a protein that stimulates or enhances the production or function of the desired nucleic acid gene product.[0391]
• As one example, manipulation of the alpA gene or gene product from[0392]E. coli(Kirby J. E., and J. E. Trempy, and S. Gottesman. Excision of a P4-like cryptic prophage leads to Alp protease expression inEscherichia coli.1994. J Bacteriol. 176:2068-2081), or homologs of this gene or gene product found in other members of the Prokaryotes, Eukaryotes or Archaebacteria, may be employed to increase the efficiency of gene expression and protein production in parent cells prior to minicell formation and/or segregated minicells postpartum.
• In addition to alpA, other exemplary[0393]E. coligenes and gene products include the clpA gene and gene product fromE. coli(Katayama Y., and S. Gottesman, and J. Pumphrey, and S. Rudikoff, and W. P. Clark, and M. R. Maurizi. The two-component, ATP-dependent Clp protease ofEscherichia coli.Purification, cloning, and mutational analysis of the ATP-binding component. 1988, J Biol Chem. 263-15226-15236); the clpB gene product fromE. coli(Kitagawa M., and C. Wada, and S. Yoshioka, and T. Yura. Expression of ClpB, an analog of the ATP-dependent proteas regulatory subunit inEscherichia coli,is controlled by a heat shock sigma factor (sigma 32). J Bacteriol. 173:4247-4253); the clpC gene product fromE. coli(Msadek T., and F. Kunst, and G. Rapoport. MecB ofBacillus subtilis,a member of the ClpC ATPase family, is a pleiotropic regulator controlling competence gene expression and growth at high temperature. 1994. Proc Natl Acad Sci USA 91:5788-5792); the clpP gene product fromE. coli(Maurizi M. R., and W. P. Clark, and Y. Katayama, and S. Rudikoff, and J. Pumphrey, and B. Bowers, and S. Gottesman. Sequence and structure of ClpP, the proteolytic component of the ATP-dependent Clp protease ofEscherichia coli.1990. J biol Chem. 265:12536-12545); the clpX gene product fromE. coli(Gottesman S., and W. P. Clark, and V. de Crecy-Lagard, and M. R. Maurizi. ClpX, an alternative subunit for the ATP-dependent Clp protease ofEscherichia coli.Sequence and in vivo activities. 1993. J Biol Chem. 268:22618-22626); the clpY gene product fromE. coli(Missiakas D., and F. Schwager, J. M. Betton, and C. Georgopoulos, S. Raina. Identification and characterization of HsIV HsIU (ClpQ ClpY) proteins involved in overall proteolysis of misfolded proteins inEscherichia coli.1996. EMBO J. 15:6899-6909); the dcp gene product fromE. coli(Becker S., and Plapp R. Location of the dcp gene on the physical map ofEscherichia coli.1992. J Bacteriol. 174:1698-1699); the degP (htrA) gene product fromE. coli(Lipinska B., and M. Zylicz, and C. Georgopoulos. The HtrA (DegP) protein, essential forEscherichia colisurvival at high temperatures, is an endopeptidase. 1990. J Bacteriol. 172:1791-1797); the ggt gene product fromE. coli(Finidori J., and Y. Laperche, and R. Haguenauer-Tsapis, and R. Barouki, and G. Guellaen, and J. Hanoune. In vitro biosynthesis and membrane insertion of gamma-glutamyl transpeptidase. 1984. J Biol Chem. 259:4687-4690); the hfl gene product fromE. coli(Cheng H. H., and H. Echols. A class ofEscherichia coliproteins controlled by the hflA locus. 1987. J Mol Biol. 196:737-740); the hflB gene product fromE. coli(Banuett F., and M. A. Hoyt, and L. McFarlane, and H. Echols, and I. Herskowitz. HflB, a newEscherichia colilocus regulating lysogeny and the level of bacteriophage lambda c11 protein. 1986. J Mol Biol. 187:213-224); the hflC gene product fromE. coli(Noble J. A., and M. A. Innis, and E. V. Koonin, and K. E. Rudd, and F. Banuett, and I. Herskowitz, TheEscherichia colihflA locus encodes a putative GTP-binding protein and two membrane proteins, one of which contains a protease-like domain. 1993. Proc Natl Acad Sci U S A. 90:10866-10870); the hflK gene product fromE. coli(Id.); the hftX gene product fromE. coli(Noble J. A., and M. A. Innis, and E. V. Koonin, and K. E. Rudd, and F. Banuett, and I. Hertzskowitz. TheEscherichia colihflA locus encodes a putative GTP-binding protein and two membrane proteins, one of which contains a protease-like domain. 1993. Proc Natl Acad Sci U S A. 90:10866-10870); the hopD gene product fromE. coli(Whitchurch C. B., and J. S. MattickEscherichia colicontains a set of genes homologous to those involved in protein secretion, DNA uptake and the assembly of type-4 fimbriae in other bacteria. 1994. Gene. 150:9-15); the htrA gene product fromE. coli(Lipinska B., and S. Sharma, and C. Georgopoulos. Sequence analysis and regulation of the htrA gene ofEscherichia coli:a sigma 32-independent mechanism of heat-inducible transcription. 1988. Nucleicc Acids Res. 16:10053-10067); the hycI gene product fromE. coli(Rossmann R., and T. Maier, and F. Lottspeich, and A. Bock. Characterisation of a proteas fromEscherichia coliinvolved in hydrogenase maturation. 1995. Eur J Biochem. 227:545-550); the iap gene product fromE. coli(Nakata A., and M. Yamaguchi, and K. Isutani, and M. Amemura.Escherichia colimutants deficient in the production of alkaline phosphatase isoszymes. 1978. J Bacteriol. 134:287-294); the lep gene product fromE. coli(Silver P., and W. Wickner. Genetic mapping of theEscherichia colileader (signal) peptidase gene (lep): a new approach for determining the map position of a cloned gene. 1983. J Bacteriol. 54:659-572); the lon gene product fromE. coli(Donch J., and J. Greenberg. Genetic analysis of lon mutants of strain K-12 ofEscherichia coli.1968. Mol Gen Genet. 103:105-115); the lsp gene product fromE. coli(Regue M., and J. Remenick, and M. tokunaga, and G. A. Mackie, and H. C. Wu. Mapping of the lipoprotein signal peptidase gene (lsp). 1984. J Bacteriol. 1984 158:632-635); the ompT gene product fromE. coli(Akiyama Y., and K. SecY protein, a membrane-embedded secretion factor ofE. coli,is cleaved by the ompT proteas in vitro. 1990. Biochem Biophys Res Commun. 167:711-715); the opdA gene product fromE. coli(Conllin C. A., and C. G. Miller. Location of the prlC (opdA) gene on the physical map ofEscherichia coli.1993. J Bacteriiol. 175:5731-5732); the orfX gene product fromE. coli(Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^nded. American Society for Microbiology, Washington D.C.); the pepA gene product fromE. coli(Stirling C. J., and S. D. Colloms, and J. F. Collins, and G. Szatmari, and D. J. Sherratt. XerB, anEscherichia coligene required for plasmid ColE1 site-specific recombination, is identical to pepA, encoding aminopeptidaseA, a protein with substantial similarity to bovine lens leucine aminopeptidase. 1989. EMBO J. 8:1623-1627); the pepD gene product fromE. coli(Henrich B., and U. Schroeder, and R. W. Frank, and R. Plapp. Accurate mapping of theEscherichia colipepD gene by sequence analysis of its 5′ flanking region. 1989. Mol Gen Genet. 215:369-373); the pepE gene product fromE. coli(Conlin C. A., and T. M. Knox, and C. G. Miller. Cloning and physical map position of an alpha-aspartyl depeptidase gene, pepE, fromEscherichia coli.1994. J Bacteriol. 176:1552-1553); the pepN gene product fromE. coli(Miller C. G., and G. Schwartz. Peptidase-deficient mutants ofEscherichia coli.1978. J Bacteriiol. 135:603-611); the pepP gene product fromE. coli(Id.); the pepQ gene product fromE. coli(Id.); the pepT gene product fromE. coli(Miller G. G., and G. Schwartz. Peptidase-deficient mutants ofEscherichia coli.1978. J Bacteriiol. 135:603-611); the pilD gene product fromE. coli(Francetic O., and S. Lory, and A. P. Pugsley. A second prepilin peptidase gene inEscherichia coliK-12. 1998, Mol Microbiol. 27:763-775); the pinA gene product fromE. coli(Hilliard J. J., and L. D. Simon, and L. Van Melderen, and M. R. Maurizi. PinA inhibits ATP hydrolysis and energy-dependent protein degradation by Lon protease. 1998. J Biol Chem. 273:524-527); the prc(tsp) gene product fromE. coli(Nagasawa H., and Y. Sakagami, and A. Suzuki, and H. Suzuki, and H. Hara, and Y. Hirota. Determination of the cleavage site involved in C-terminal processing of penicillin-binding proein 3 ofEscherichia coli.1989. J Bacteriol. 171:5890-5893); the prlC gene product fromE. coli(Jiang X., and M. Zhang, and Y. Ding, and J. Yao, and H. Chen, and D. Zhu, and M. Muramatu.Escherichia coliprlC gene encodes a trypsin-like proteinase regulating the cell cycle. 1998. J Biochem (Tokyo) 128:980-985); the protease V gene product fromE. coli(Berlyn, M. K. B. et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9, In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^nded. American Society for Microbiology, Washington, D.C.); the protease VI gene product fromE. coli(Id.); the protease In gene product fromE. coli(Id.); the protease Fa gene product fromE. colior homologues (Id.); the protease Mi gene product fromE. coli(Id.); the protease So gene product fromE. coli(Id.); the ptrA gene product fromE. coli(Id.); the ptrB gene product fromE. coli(Id.); the sypB gene product fromE. coli(Barends S., and A. W. Karzai, and R. T. Sauer, and J. Wower, and B. Kraal. Simultaneous an functional binding of SmpB and EF-Tu-TP to the analyl acceptor arm of tmRNA. 2001. J Mol Biol. 314:9-21); the sohB gene product fromE. coli(Baird L., and B. Lipinska, and S. Raina, and C. Georgopoulos. Identification of theEscherichia colisohB gene, a multicopy suppressor of the HtrA (DegP) null phenotype. 1991. J Bacteriol. 173-5763-5770); the sspA gene product fromE. coli(Ichihara S., and T. Suzuki, and M. Suzuki, and C. Mizushima. Molecular cloning and sequencing of the sppA gene and characterization of the encoded proteas IV, a signal peptide peptidase ofEscherichia coli.1986. J Biol Chem. 261;9405-9411); the tesA gene product fromE. coli(Cho H., and J. E. Cronan Jr.Escherichia colithioesterase I, molecular cloning and sequencing of the structural gene and identification as a periplasmic enzyme. 1993 J Biol Chem. 268:9238-9245); the tufA gene product fromE. coli(Ang., and J. S. Lee, and J. D. Friesen. Evidence for an internal promoter preceding tufA in the str operon ofEscherichia coli.J Bacteriol. 149:548-553); the tufb gene product fromE. coli(Mihajima A., and M. Shibuya, and Y. Kaziro. Construction and characterization of the two hybrid Col1E1 plasmids carryingEscherichia colitufb gene. 1979. FEBS Lett. 102:207-210); the ybaU gene product fromE. coli(Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Resnikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^nded. American Society for Microbiology, Washington, D.C.); the ssrA gene (tmRNA, 10sA RNA) product fromE. coli(Oh B. K., and A. K. Chauhan, and K. Isono, and D. Apirion. Location of a gene (ssrA) for a small, stable RNA 910Sa RNA) in theEscherichia colichromosome. 1990. J Bacteriol. 172:4708-4709); and the ssrB gene fromE. coli(Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Ummbarger 9eds.).Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^nded. American Society for Microbiology, Washington, D.C.).
• II.C.13. Chaperones[0394]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and functional protein production in minicells. By way of non-limiting example, these techniques may include modification of chaperones and chaperonins, i.e., endogenous and/or exogenous protein components that monitor the unfolded state of translated proteins allowing proper folding and/or secretion, membrane insertion, or soluble multimeric assembly of expressed proteins in the parental cell prior to minicell formation and/or the segregated minicell cytoplasm, membrane, periplasm, and/or extracellular environment. See Gottesman et al., Protein folding and unfolding by[0395]Escherichia colichaperones and chaperonins, Current Op. Microbiol. 3:197-202, 2000; and Mayhew et al., “Molecular Chaperone Proteins,” Chapter 61 in:Escherichia coli and Salmonella typhimurium: Cellular and Molecular Biology,2nd Ed., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996,Volume 1, pages 922-937, and references cited therein.
• These applications may, but are not limited to increased or decreased chaperone production, increased or decreased intramolecular activity of a chaperone, increased or decreased physiological function of a chaperone, or deletion, substitution, inversion, translocation or insertion into, or mutation of, a gene encoding a chaperone. By way of non-limiting example, increased production of a chaperone may occur through increased chaperone gene dosage (increased copy number of a given gene under the control of the native or artificial promotor where this gene may be on a plasmid or in more than one copy on the chromosome), modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, cloning on a plasmid under the control of the native or artificial promotor, and increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the chaperone gene or gene product. By way of non-limiting example, decreased production of a chaperone may occur through modification of the native regulatory elements, including, but not limited to the promotor or operator region(s) of DNA, or ribosomal binding sites on RNA, relevant repressors/silencers, relevant activators/enhancers, or relevant antisense nucleic acid or nucleic acid analog, through cloning on a plasmid under the control of the native regulatory region containing mutations or an artificial promotor, either or both of which resulting in decreased chaperone production, and through increased or decreased production of native or artificial promotor regulatory element(s) controlling production of the chaperone gene or gene product. By definition, intramolecular activity refers to the enzymatic function, structure-dependent function, e.g. the capacity of chaperone to interact in a protein-protein, protein-nucleic acid, or protein-lipid complex, and/or carrier function, e.g. the capacity to bind, either covalently or non-covalently small organic or inorganic molecules, protein(s), carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s). By way of non-limiting example, alteration of intramolecular activity may be accomplished by mutation of the chaperone gene, in vivo or in vitro chemical modification of Chaperone, inhibitor molecules against the function of chaperone, e.g. competitive, non-competitive, or uncompetitive enzymatic inhibitors, inhibitors that prevent protein-protein, protein-nucleic acid, or protein-lipid interactions, e.g. expression or introduction of dominant-negative or dominant-positive chaperone or other protein fragment(s), or other carbohydrate(s), fatty acid(s), lipid(s), and nucleic acid(s) that may act directly or allosterically upon Chaperone, and/or modification of protein, carbohydrate, fatty acid, lipid, or nucleic acid moieties that modify the chaperone gene or gene product to create the functional protein. By definition, physiological function refers to the effects resulting from an intramolecular interaction between Chaperone and other protein, carbohydrate, fatty acid, lipid, nucleic acid, or other molecule(s) in or on the cell or the action of a product or products resulting from such an interaction. By way of non-limiting example, physiological function may be the act or result of intermolecular phosphorylation, biotinylation, methylation, acylation, glycosylation, and/or other signaling event; this function may be the result of a protein-protein, protein-nucleic acid, or protein-lipid interaction resulting in a functional moiety; this function may be to interact with the membrane to recruit other molecules to this compartment of the cell; this function may be to regulate the transcription and/or translation of chaperone, other protein, or nucleic acid; and this function may be to stimulate the function of another process that is not yet described or understood.[0396]
• By way of non-limiting example, chaperone genes may be any of the[0397]E. coligenes listed below, as well as any homologs thereof from prokaryotes, exukariutes, arcahebacteria, or organelles (mitochondria, chloroplasts, plastids, etc.). ExemplaryE. coligenes encoding chaperones include, by way of non-limiting example, the cbpA gene (Shiozawa T., and C. Ueguchi, and T. Mizuno. The rpoD gene functions as a multicopy suppressor for mutations in the chaperones, CbpA, DnaJ and DnaK, inEscherichia coli.1996 FEMS Microbiol Lett. 138:245-250): the clpB gene (Squires C. L., and S. Pedersen, and B. M. Ross, and C. Squires. ClpB is theEscherichia coliheat shock protein F84.1. 1991. J Bacteriol. 173:4254-4262); the dnaK gene (Kroczynska B., and S. Y. Blond. Cloning and characterization of a new soluble murine J-domain protein that stimulates BiP, Hsc70 and DnaK ATPase activity with different efficiencies. 2001. Gene. 273:267-274); the dnaJ gene (Kedzierska S., and E. Matuszewska. The effect of co-overproduction of DnaK/DnaJ/GrpE and ClpB proteins on the removal of heat-aggregated proteins fromEscherichia coliDelta clpB mutant cells--new insight into the role of Hsp70 in a functional cooperation with Hsp100. 2001. FEMS Microbiol Lett. 204:355-360); the ecpD gene (Raina S., and D. Missiakas, and L. Baird, and S. Kumar, and C. Georgopoulos. Identification and transcriptional analysis of theEscherichia colihtrE operon which is homologous to pap and related pilin operons. 1993. J Bacteriol. 175:5009-5021); the ffh gene (Muller, M., et al. 1002. Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane. Prog. Nucleic Acid Res. Mol. Biol. 66:107-157); 4.5S RNA (Muller, M., et al. 1002. Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane. Prog. Nucleic Acid Res. Mol. Biol. 66:107-157); the FtsY gene (Muller, M., et al. 1002. Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane. Prog. Nucleic Acid Res. Mol. Biol. 66: 107-157);the fimC gene (Klemm P., and B. J. Jorgensen, and I. van Die, and H. de Ree, and H. Bergmans. The fim genes responsible for synthesis oftype 1 fimbriae inEscherichia coli,cloning and genetic organization. 1985. Mol Gen Genet. 199:410-414); the groE gene (Burton Z. F., and D. Eisenberg. A procedure for rapid isolation of both groE protein and glutamine synthetase fromE coli.1980. Arch Biochem Biophys. 205:478-488); the groL gene (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D. C.); the groS gene (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D.C.); the hptG gene (Berlyn, M. K. B., et al. 1996. Linkage map ofEscherichia coliK-12, Edition 9. In F. C. Neidhardt, R. Curtiss, J. L. Ingraham, E. C. C. Lin, K. B. Low, B. Magasanik, W. S. Reznikoff, M. Riley, M. Schaechter, and H. E. Umbarger (eds.).Escherichia coli and Salmonella typhimurium: cellular and molecular biology,2nd ed. American Society for Microbiology, Washington D.C.); the hscA gene (Takahashi Y., and M. Nakamura. Functional assignment of the ORF2-iscS-iscU-iscA-hscB-hscA-fdx-ORF3 gene cluster involved in the assembly of Fe-S clusters inEscherichia coli.1999. J Biochem (Tokyo). 126:917-926); the ibpA gene (Lund P. A. Microbial molecular chaperones. 2001. Adv Microb Physiol. 44:93-140); the papJ gene (Tennent, J. M., et al. 1990. Integrity ofEscherichia coliP pili during biogenesis: properties and role of PapJ. Mol. Microbiol. 4:747-758); the secB gene (Lecker, S., et al. 1989. Three pure chaperone proteins ofEscherichia coli—SecB, trigger factor and GroEL—form soluble complexes with precursor proteins in vitro. EMBO J. 8:2703-2709); and the tig gene (Lecker, S., et al. 1989. Three pure chaperone proteins ofEscherichia coli—SecB, trigger factor and GroEL—form soluble complexes with precursor proteins in vitro. EMBO J. 8:2703-2709); the secE gene (Muller, M., et al. 1002. Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane. Prog. Nucleic Acid Res. Mol. Biol. 66:107-157); and the secY gene (Muller, M., et al. 1002. Protein traffic in bacteria: multiple routes from the ribosome to and across the membrane. Prog. Nucleic Acid Res. Mol. Biol. 66:107-157).
• II.C.14. Export Apparatus and Membrane Targeting[0398]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in parental cells prior to minicell formation and/or in the segregated minicells. By way of non-limiting example, these techniques may include construction of chimeric proteins including, but not limited to, coupling the expressed protein of interest with native Eubacterial, Eukaryotic, Archeabacterial or organellar leader sequences to drive membrane insertion or secretion of the protein of interest to the periplasm or extracellular environment. In addition to using native leader sequences, these minicell expression constructs may also include proteolytic cleavage sites to remove the leader sequence following insertion into the membrane or secretion. These proteolytic cleavage sites may be native to the organism from which the minicell is derived or non-native. In the latter example, also included in the system are the non-native protease that recognizes the non-native proteolytic cleavage site.[0399]
• Non-limiting examples of these leader sequences may be the leader from the STII protein (Voss, T., et al. 1994. Periplasmic expression of human interferon-alpha 2c in[0400]Escherichia coliresults in a correctly folded molecule. Biochem. J. 298:719-725), maltose binding protein (malE) (Ito, K. 1982. Purification of the precursor form of maltose-binding protein, a periplasmic protein ofEscherichia coli.J. Biol. Chem. 257:9895-9897), phoA (Jobling, M. G., et al. 1997. Construction and characterization of versatile cloning vectors for efficient delivery of native foreign proteins to the periplasm ofEscherichia coli.Plasmid. 38:158-173), lamB (Wong, E. Y., et al. 1988. Expression of secreted insulin-like growth factor-1 inEscherichia coli.Gene. 68:193-203), ompA (Loo, T., et al. 2002. Using secretion to solve a solubility problem: high-yield expression inEscherichia coliand purification of the bacterial glycoamidase PNGase F. Protein Expr. Purif. 24:90-98), or pelB (Molloy, P. E., et al. 1998. Production of soluble single-chain T-cell receptor fragments inEscherichia colitrxB mutants. Mol. Immunol. 35:73-81).
• In addition to these leader sequences, mutations in the cellular export machinery may be employed to increase the promiscuity of export to display or export sequences with non-optimized leader sequences. Non-limiting examples of genes that may be altered to increase export promiscuity are mutations in secY (prlA4) (Derman, A. I., et al. 1993. A signal sequence is not required for protein export in prlA mutants of[0401]Escherichia coli.EMBO J. 12:879-888), and secE (Harris, C. R., and T. J. Silhavy. 1999. Mapping an interface of SecY (PrlA) and SecE (PrlG) by using synthetic phenotypes and in vivo cross-linking. J. Bacteriol. 181:3438-3444).
• II.C.15. Increasing Stability and Solubility[0402]
• Included in the design of the invention are techniques that increase the efficiency of gene expression and protein production in parental cells prior to minicell formation and/or in the segregated minicells. By way of non-limiting example, these techniques may include construction of chimericlfusion proteins including, but not limited to, coupling the expressed protein of interest with native Eubacterial, Eukaryotic, Archeabacterial or organellar solublizing sequences. As used herein, “solublizing sequences” are complete or truncated amino acid sequences that increase the solubility of the expressed membrane protein of interest. This increased solubility may be used to increase the lifetime of the soluble state until proper membrane insertion may take place. By way of non-limiting example, these soluble chimeric fusion proteins may be ubiquitin (Power, R. F., et al. 1990. High level expression of a truncated chicken progesterone receptor in[0403]Escherichia coli.J. Biol. Chem. 265:1419-1424), thioredoxin (LaVallie, E. R., et al. 1993. A thioredoxin gene fusion expression system that circumvents inclusion body formation in theE. colicytoplasm. Biotechnology (N. Y.) 11:187-193; Kapust, R. B., and D. S. Waugh. 1999.Escherichia colimaltose-binding protein is uncommonly effective at promoting the solubility of polypeptides to which it is fused. Protein Sci. 8:1668-1674), the dsbA gene product (Winter, J., et al. 2001. Increased production of human proinsulin in the periplasmic space ofEscherichia coliby fusion to DsbA. J. Biotechnol. 84:175-185), the SPG protein (Murphy, J. P., et al. 1992. Amplified expression and large-scale purification of protein G′. Bioseparation 3:63-71), the malE gene product (maltose-binding protein) (Hampe, W., et al. 2000. Engineering of a proteolytically stable human beta 2-adrenergic receptor/maltose-binding protein fusion and production of the chimeric protein inEscherichia coliand baculovirus-infected insect cells. J. Biotechnol. 77:219-234; Kapust et al.,Escherichia colimaltose-binding protein is uncommonly effective at promoting the solubility of polypeptides to which it is fused, Protein Sci. 8:1668-1674, 1999), glutathione-s-transferase (GST); and/or nuclease A (Meeker et al., A fusion protein between serum amyloid A and staphylococcal nuclease—synthesis, purification, and structural studies, Proteins 30:381-387, 1998). In addition to these proteins, Staphylococcal protein A, beta-galactosidase, S-peptide, myosin heavy chain, dihydrofolate reductase, T4 p55, growth hormone N terminus,E. coliHemolysin A, bacteriophage lambda cII protein, TrpE, and TrpLE proteins may also be used as fusion proteins to increase protein expression and/or solubility (Makrides, Stratagies for Achieving High-Level Expression of Genes inEscherichia coli,Microbiol. Rev. 60:512-538).
• III. Preparation of Minicells[0404]
• III.A. Parent Cell Mutations[0405]
• Although it has been reported that relatively few molecules of endogenous RNA polymerase segregate into minicells (Shepherd et al., Cytoplasmic RNA Polymerase in[0406]Escherichia coli,J Bacteriol 183:2527-34, 2001), other reports and results indicate that many RNA Polymerase molecules follow plasmids into minicells (Funnell and Gagnier, Partition of P1 plasmids in Escherichia cole mukB chromosomal partition mutants, J Bacteriol 177:2381-6, 1995). In any event, applicants have discovered that the introduction of an exogenous RNA polymerase to minicell-producing cells enhances expression of episomal elements in minicells. Such enhanced expression may allow for the successful expression of proteins in minicells, wherein such proteins are expressed poorly or not at all in unmodified minicells. In order to maximize the amount of RNA transcription from episomal elements in minicells, minicell-producing cell lines that express an RNA polymerase specific for certain episomal expression elements may be used. An example of anE. colistrain of this type, designated MC-T7, was created and used as is described in the Examples. Those skilled in the art will be able to make and use equivalent strains based on the present disclosure and their knowledge of the art.
• Minicell-producing cells may comprise mutations that augment preparative steps. For example, lipopolysaccharide (LPS) synthesis in[0407]E. coliincludes the lipid A biosynthetic pathway. Four of the genes in this pathway have now been identified and sequenced, and three of them are located in a complex operon that also contains genes involved in DNA and phospholipid synthesis. The rfa gene cluster, which contains many of the genes for LPS core synthesis, includes at least 17 genes. The rfb gene cluster encodes protein involved in O-antigen synthesis, and rfb genes have been sequenced from a number of serotypes and exhibit the genetic polymorphism anticipated on the basis of the chemical complexity of the O antigens. See Schnaitman and Klena, Genetics of lipopolysaccharide biosynthesis in enteric bacteria, Microbiol. Rev. 57:655-82, 1993. When present, alone, or in combination, the rfb and oms mutations cause alterations in the eubacterial membrane that make it more sensitive to lysozyme and other agents used to process minicells. Similarly, the rfa (Chen, L., and W. G. Coleman Jr. 1993. Cloning and characterization of theEscherichia coliK-12 rfa-2 (rfaC) gene, a gene required for lipopolysaccharide inner core synthesis. J. Bacteriol. 175:2534-2540), IpcA (Brooke, J. S., and M. A. Valvano. 1996. Biosynthesis of inner core lipopolysaccharide in enteric bacteria identification and characterization of a conserved phosphoheptose isomerase. J. Biol. Chem. 271:3608-3614), and lpcB (Kadrman, J. L., et al. 1998. Cloning and overexpression of glycosyltransferases that generate the lipopolysaccharide core ofRhizobium leguminosarum.J. Biol. Chem. 273:26432-26440) mutations, when present alone or in combination, cause alterations in lipopolysaccharides in the outer membrane causing cells to be more sensitive to lysozyme and agents used to process minicells. In addition, such mutations can be used to reduce the potential antigenicity and/or toxicity of minicells.
• III.B. Culturing Conditions[0408]
• Included in the design of the invention are the conditions to grow parental cells from which minicells will be produced. Non-limiting examples herein are drawn to conditions for growing[0409]E. coliparental cells to produce minicells derived fromE. coliparental cells. Non-limiting examples for growth media may include rich media, e.g. Luria broth (LB), defined minimal media, e.g. M63 salts with defined carbon, nitrogen, phosphate, magnesium, and sulfate levels, and complex minimal media, e.g. defined minimal media with casamino acid supplement. This growth may be performed in culture tubes, shake flasks (using a standard air incubator, or modified bioreactor shake flask attachment), or bioreactor. Growth of parental cells may include supplemented additions to assist regulation of expression constructs listed in the sections above. These supplements may include, but are not limited to dextrose, phosphate, inorganic salts, ribonucleic acids, deoxyribonucleic acids, buffering agents, thiamine, or other chemical that stimulates growth, stabilizes growth, serves as an osmo-protectant, regulates gene expression, and/or applies selective pressure to mutation, and/or marker selection. These mutations may include an amino acid or nucleotide auxotrophy, while the selectable marker may include transposable elements, plasmids, bacteriophage, and/or auxotrophic or antibiotic resistance marker. Growth conditions may also require temperature adjustments, carbon alternations, and/or oxygen-level modifications to stimulate temperature sensitive mutations found in designed gene products for a given desired phenotype and optimize culture conditions.
• By way of non-limiting example, production of minicells and protein production may occur by using either of two general approaches or any combination of each. First, minicells may be formed, purified, and then contained expression elements may be stimulated to produce their encoded gene products. Second, parental cells, from which the minicells are derived, may be stimulated to express the protein of interest and segregate minicells simultaneously. Finally, any timing variable of minicell formation and protein production may be used to optimize protein and minicell production to best serve the desired application. The two general approaches are shown in the sections below.[0410]
• III.C. Manipulation of Genetic Expression in Minicell Production[0411]
• Included in the design of the invention are methods that increase the efficiency, rate and/or level of gene expression and protein production in parent cells and/or minicells. Such methods include, but are not limited to, the following.[0412]
• By way of non-limiting example, parental cells are grown overnight in the appropriate media. From this culture, the cells are subcultured into the same media and monitored for growth. At the appropriate cell density, the cultures are induced for minicell production using any of the switching mechanisms discussed in section II.B. regulating any construct discussed in section II.A. Non-limiting examples of this minicell-inducing switching mechanism may be the ileR gene product regulating the production of the hns minicell-inducing gene product or the melR gene product regulating the production of the minB minicell-inducing gene product. Following minicell induction, the culture is allowed to continue growth until the desired concentration of minicells is obtained. At this point, the mincells are separated from the parental cells as described in section II.E. Purified minicells are induced for protein production by triggering the genetic switching mechanism that segregated into the minicell upon separation from the parental cell. By way of non-limiting example, this genetic switching mechanism may be any of those discussed in section I.B. regulating the production of any protein of interest. Furthermore, at this point or during the production of minicells the peripheral gene expression, production, and assembly machinery discussed in section II.C. may be triggered to assist in this process. By way of non-limiting example, the groEL complex may be triggered using the temperature sensitive lambda cI inducible system from a co-segregant plasmid to assist in the proper assembly of the expressed protein of interest.[0413]
• III.D. Separation of Minicells from Parent Cells[0414]
• A variety of methods are used to separate minicells from parent cells (i.e., the cells from which the minicells are produced) in a mixture of parent cells and minicells. In general, such methods are physical, biochemical and genetic, and can be used in combination.[0415]
• III.D.1.Physical Separation of Minicells from Parent Cells[0416]
• By way of non-limiting example, minicells are separated from parent cells glass-fiber filtration (Christen et al., Gene 23:195-198, 1983), and differential and zonal centrifugation (Barker et al., J. Gen. Microbiol. 111:387-396, 1979), size-exclusion chromatography, e.g. gel-filtration, differential sonication (Reeve, J. N., and N. H. Mendelson. 1973. Pronase digestion of amino acid binding components on the surface of[0417]Bacillus subtiliscells and minicells. Biochem. Biophys. Res. Commun. 53:1325-1330), and UV-irradiation (Tankersley, W. G., and J. M. Woodward. 1973. Induction and isoloation of non-replicative minicells ofSalmonella typhimuiumand their use as immunogens in mice. Bacteriol. Proc. 97).
• Some techniques involve different centrifugation techniques, e.g., differential and zonal centrifugation. By way of non-limiting example, minicells may be purified by the double sucrose gradient purification technique described by Frazer and Curtiss, Curr. Topics Microbiol. Immunol. 69:1-84, 1975. The first centrifugation involves differential centrifugation, which separates parent cells from minicells based on differences in size and/or density. The percent of sucrose in the gradient (graduated from about 5 to about 20%), Ficol or glycerol is designed to allow only parent cells to pass through the gradient.[0418]
• The supernatant, which is enriched for minicells, is then separated from the pellet and is spun at a much higher rate (e.g., ≧11,000 g). This pellets the minicells and any parent cells that did not pellet out in the first spin. The pellet is then resuspended and layered on a sucrose gradient.[0419]
• The band containing minicells is collected, pelleted by centrifugation, and loaded on another gradient. This procedure is repeated until the minicell preparation is essentially depleted of parent cells, or has a concentration of parent cells that is low enough so as to not interfere with a chosen i minicell application or activity. By way of non-limiting example, buffers and media used in these gradient and resuspension steps may be LB, defined minimal media, e.g. M63 salts with defined carbon, nitrogen, phosphate, magnesium, and sulfate levels, complex minimal media, e.g. defined minimal media with casamino acid supplement, and/or other buffer or media that serves as an osmo-protectant, stabilizing agent, and/or energy source, or may contain agents that limit the growth of contaminating parental cells, e.g azide, antibiotic, or lack an auxotrophic supplemental requirement, e.g. thiamine.[0420]
• Other physical methods may also be used to remove parent cells from minicell preparations. By way of non-limiting example, mixtures of parent cells and minicells are frozen to −20° C. and then thawed slowly (Frazer and Curtiss, Curr. Topics Microbiol. Immunol. 69:1-84, 1975).[0421]
• III.D.2.Biochemical Separation of Minicells from Parent Cells[0422]
• Contaminating parental cells may be eliminated from minicell preparations by incubation in the presence of an agent, or under a set of conditions, that selectively kills dividing cells. Because minicells can neither grow nor divide, they are resistant to such treatments.[0423]
• Examples of biochemical conditions that prevent or kill dividing parental cells is treatment with a antibacterial agent, such as penicillin or derivatives of penicillin. Penicillin has two potential affects. First, penicillin prevent cell wall formation and leads to lysis of dividing cells. Second, prior to lysis dividing cells form filaments that may assist in the physical separation steps described in section III.E.1. In addition to penicillin and its derivatives, other agents may be used to prevent division of parental cells. Such agents may include azide. Azide is a reversible inhibitor of electron transport, and thus prevents cell division. As another example, D-cycloserine or phage MS2 lysis protein may also serve as a biochemical approach to eliminate or inhibit dividing parental cells. (Markiewicz et al., FEMS Microbiol. Lett. 70:119-123, 1992). Khachatourians (U.S. Pat. No. 4,311,797) states that it may be desirable to incubate minicell/parent cell mixtures in brain heart infusion broth at 36° C. to 38° C. prior to the addition of penicillin G and further incubations.[0424]
• III.D.3.Genetic Separation of Minicells from Parent Cells[0425]
• Alternatively or additionally, various techniques may be used to selectively kill, preferably lyse, parent cells. For example, although minicells can internally retain M13 phage in the plasmid stage of the M13 life cycle, they are refractory to infection and lysis by M 13 phage (Staudenbauer et al., Mol. Gen. Genet. 138:203-212, 1975). In contrast, parent cells are infected and lysed by M13 and are thus are selectively removed from a mixture comprising parent cells and minicells. A mixture comprising parent cells and minicells is treated with M13 phage at an M.O.I.=5 (phage:cells). The infection is allowed to continue to a point where ≧50% of the parent cells are lysed, preferably ≧75%, more preferably ≧95% most preferably ≧99%; and ≦25% of the minicells are lysed or killed, preferably ≦15%, most preferably ≦1%.[0426]
• As another non-limiting example of a method by which parent cells can be selectively killed, and preferably lysed, a chromosome of a parent cell may include a conditionally lethal gene. The induction of the chromosomal lethal gene will result in the destruction of parent cells, but will not affect minicells as they lack the chromosome harboring the conditionally lethal gene. As one example, a parent cell may contain a chromosomal integrated bacteriophage comprising a conditionally lethal gene. One example of such a bacteriophage is an integrated lambda phage that has a temperature sensitive repressor gene (e.g., lambda cI857). Induction of this phage, which results in the destruction of the parent cells but not of the achromosomal minicells, is achieved by simply raising the temperature of the growth media. A preferred bacteriophage to be used in this method is one that kills and/or lyses the parent cells but does not produce infective particles. One non-limiting example of this type of phage is one that lyses a cell but which has been engineered to as to not produce capsid proteins that are surround and protect phage DNA in infective particles. That is, capsid proteins are required for the production of infective particles.[0427]
• As another non-limiting example of a method by which parent cells can be selectively killed or lysed, toxic proteins may be expressed that lead to parental cell lysis. By way of non-limiting example, these inducible constructs may employ a system described in section II.B. to control the expression of a phage holing gene. Holin genes fall with in at least 35 different families with no detectable orthologous relationships (Grundling, A., et al. 2001. Holins kill without warning. Proc. Natl. Acad. Sci. 98:9348-9352) of which each and any may be used to lyse parental cells to improve the purity of minicell preparations.[0428]
• Gram negative eubacterial cells and minicells are bounded by an inner membrane, which is surrounded by a cell wall, wherein the cell wall is itself enclosed within an outer membrane. That is, proceeding from the external environment to the cytoplasm of a minicell, a molecule first encounters the outer membrane (OM), then the cell wall and finally, the inner membrane (IM). In different aspects of the invention, it is preferred to disrupt or degrade the OM, cell wall or IM of a eubacterial minicell. Such treatments are used, by way of non-limiting example, in order to increase or decrease the immunogenicity, and/or to alter the permeability characteristics, of a minicell.[0429]
• Eubacterial cells and minicells with altered membranes and/or cell walls are called “poroplasts™” “spheroplasts,” and “protoplasts.” Herein, the terms “spheroplast” and “protoplast” refer to spheroplasts and protoplasts prepared from minicells. In contrast, “cellular spheroplasts” and “cellular protoplasts” refer to spheroplasts and protoplasts prepared from cells. Also, as used herein, the term “minicell” encompasses not only minicells per se but also encompasses poroplasts™, spheroplasts and protoplasts.[0430]
• In a poroplast, the eubacterial outer membrane (OM) and LPS have been removed. In a spheroplast, portions of a disrupted eubacterial OM and/or disrupted cell wall either may remain associated with the inner membrane of the minicell, but the membrane and cell wall is nonetheless porous because the permeability of the disrupted OM and cell wall has been increased. A membrane is said to be “disrupted” when the membrane's structure has been treated with an agent, or incubated under conditions, that leads to the partial degradation of the membrane, thereby increasing the permeability thereof. In contrast, a membrane that has been “degraded” is essentially, for the applicable intents and purposes, removed. In preferred embodiments, irrespective of the condition of the OM and cell wall, the eubacterial inner membrane is not disrupted, and membrane proteins displayed on the inner membrane are accessible to compounds that are brought into contact with the minicell, poroplast, spheroplast, protoplast or cellular poroplast, as the case may be.[0431]
• III.E.2. Poroplasts™[0432]
• For various applications poroplasted minicells are capable of preserving the cytoplasmic integrity while producing increased stability over that of naked protoplasts. Maintenance of the cell wall in poroplasted minicells increases the osmotic resistance, mechanical resistance and storage capacity over protoplasts while permitting passage of small and medium size proteins and molecules through the porous cell wall. A poroplast is a Gram negative bacterium that has its outer membrane only removed. The production of poroplasts involves a modification of the procedure to make protoplasts to remove the outer membrane (Birdsell et al., Production and ultrastructure of lysozyme and ethylenediaminetetraacetate-Lysozyme Spheroplasts of[0433]Escherichia coli,J. Bacteriology 93: 427-437, 1967; Weiss, Protoplast formation inEscherichia coli.J. Bacteriol. 128:668-670, 1976). Like protoplasts, measuring the total LPS that remains in the poroplast preparation may be used to monitor the removal of the outer membrane. Endotoxin kits and antibodies reactive against LPS may be used to measure LPS in solution; increasing amounts of soluble LPS indicates decreased retention of LPS by protoplants. This assay thus makes it possible to quantify the percent removal of total outer membrane from the poroplasted minicells.
• Several chemical and physical techniques have been employed to remove the outer membrane of gram negative bacteria. Chemical techniques include the use of EDTA in Tris to make cells susceptible to hydrophobic agents such as actinomycin C. Leive L. The barrier function of the gram-negative envelope. Ann N Y Acad Sci. 1974 May 10;235(0): 109-29.; Voll M J, Leive L. Actinomycin resistance and actinomycin excretion in a mutant of[0434]Escherichia coli.J Bacteriol. 1970 May; 102(2):600-2; Lactic Acid disruption of the outer membrane as measured by the uptake of hydrophobic flourophores; Alakomi H L, Skytta E, Saarela M, Mattila-Sandholm T, Latva-Kala K, Helander I M. Lactic acid permeabilizes gram-negative bacteria by disrupting the outer membrane. Appl Environ Microbiol. 2000 May;66(5):2001-5; and Polymyxin B disruption as measured by periplasmic constituent release (Teuber M, Cerny G. Release of the periplasmic ribonuclease I into the medium fromEscherichia colitreated with the membrane-active polypeptide antibiotic polymyxin B. FEBS Lett. 1970 May 11;8(1):49-51). Physical techniques include the use of osmodifferentiation to facilitate the disruption of the OM. Neu H C, Heppel L A. The release of enzymes fromEscherichia coliby osmotic shock and during the formation of spheroplasts. J Biol Chem. September 1965; 240(9):3685-92. See also Voll M J, Leive L. Actinomycin resistance and actinomycin excretion in a mutant ofEscherichia coli.J Bacteriol. 1970 May;102(2):600-2; Fiil A, Branton D. Changes in the plasma membrane ofEscherichia coliduring magnesium starvation. J Bacteriol. June 1969;98(3):1320-7; and Matsuyama S, Fujita Y, Mizushima S. SecD is involved in the release of translocated secretory proteins from the cytoplasmic membrane ofEscherichia coli.EMBO J. January 1993; 12(1):265-70.
• III.E.3. Spheroplasts[0435]
• A spheroplast is a bacterial minicell that has a disrupted cell wall and/or a disrupted OM. Unlike eubacterial minicells and poroplasts, which have a cell well and can thus retain their shape despite changes in osmotic conditions, the absence of an intact cell wall in spheroplasts means that these minicells do not have a rigid form.[0436]
• III.E.4. Protoplasts[0437]
• A protoplast is a bacterium that has its outer membrane and cell wall removed. The production of protoplasts involves the use of lysozyme and high salt buffers to remove the outer membrane and cell wall (Birdsell et al., Production and ultrastructure of lysozyme and ethylenediaminetetraacetate-Lysozyme Spheroplasts of[0438]Escherichia coli,J. Bacteriology 93: 427-437, 1967; Weiss, Protoplast formation inEscherichia coli.J. Bacteriol. 128:668-670, 1976). Various commercially available lysozymes can be used in such protocols. Measuring the total LPS that remains in the protoplast preparation is used to monitor the removal of the outer membrane. Endotoxin kits assays can be used to measure LPS in solution; increasing amounts of soluble LPS indicates decreased retention of LPS by protoplasts. This assay thus makes it possible to quantify the percent removal of total outer membrane from the minicells. Endotoxin assays are commerically available from, e.g., BioWhittaker Molecular Applications (Rockland, Me.)
• For minicell applications that utilize bacterial-derived minicells, it may be necessary to remove the outer membrane of Gram-negative cells and/or the cell wall of any bacterial-derived minicell. For Gram-positive bacterial cells, removal of the cell wall may be easily accomplished using lysozyme. This enzyme degrades the cell wall allowing easy removal of now soluble cell wall components from the pelletable protoplasted minicells. In a more complex system, the cell wall and outer membrane of Gram-negative cells may be removed by combination treatment with EDTA and lysozyme using a step-wise approach in the presence of an osmoprotecting agent (Birdsell, et al. 1967. Production and ultrastructure of lysozyme and ethylenediaminetetraacetate-lysozyme spheroplasts of[0439]E. coli,J. Bacteriol. 93:427-437; Weiss, 1976. Protoplast formation inE. coli.J. Bacteriol. 128:668-670). By non-limitingBy way of non-limiting example, this osmoprotectant may be sucrose and/or glycerol. It has been found that the concentration of the osmoprotectant sucrose, the cell wall digesting enzyme lysozyme, and chelator EDTA can be optimized to increase the quality of the protoplasts produced. Separation of either prepared Gram-negative spheroplasts prepared in either fashion from removed remaining LPS may occur through exposure of the spheroplast mixture to an anti-LPS antibody. By non-limitingBy way of non-limiting example, the anti-LPS antibody may be covalently or non-covalently attached to magnetic, agarose, sepharose, sepheracyl, polyacrylamide, and/or sephadex beads. Following incubation, LPS is removed from the mixture using a magnet or slow centrifugation resulting in a protoplast-enriched supernatant.
• Monitoring loss of LPS may occur through dot-blot analysis of protoplast mixtures or various commercially available endotoxin kit assays can be used to measure LPS in solution; increasing amounts of soluble LPS indicates decreased retention of LPS by protoplasts. This immuno assay may comprise a step of comparing the signal to a standard curve in order to quantify the percent removal of total outer membrane from the minicells. Other endotoxin assays, such as the LAL Systems from BioWhittaker, are commercially available. LPS removal has been measured by gas chromatography of fatty acid methyl esters. Alakomi H L, Skytta E, Saarela M, Mattila-Sandholm T, Latva-Kala K, Helander I M. Lactic acid permeabilizes gram-negative bacteria by disrupting the outer membrane. Appl Environ Microbiol. May 2000;66(5):2001-5.[0440]
• In order to reduce, preferably eliminate, in vivo antigenic potential of minicells or minicell protoplasts, minicell protoplasts may be treated to remove undesirable surface components. Minicell protoplasts so treated are referred to as “denuded minicells” a term that encompasses both spheroplasts and protoplasts. Denuding minicells or minicell protoplasts is accomplished by treatment with one or more enzymes or conditions that selectively or preferentially removes or make less antigenic externally displayed proteins. As one non-limiting example, the protease trypsin is used to digest exposed proteins on the surface of these particles. In this example, the proteolytic activity of tryp sin may be modulated or terminated by the additional of a soybean trypsin inhibitor. Non-limiting examples of other proteases that additionally or alternatively may be used include chymotrypsin, papain, elastase, proteinase K and pepsin. For some such proteases, it may be necessary to limit the extent of proteolysis by, e.g., using a suboptimal concentration of protease or by allowing the reaction to proceed for a suboptimal period of time. By the term “suboptimal,” it is meant that complete digestion is not achieved under such conditions, even though the reactions could proceed to completion under other (i.e., optimal) conditions.[0441]
• It is sometimes preferred to use molecular genetic techniques to create mutant derivatives of exogenous proteins that (1) are resistant to the proteases or other enzymes used to prepare minicells and (2) retain the desired biological activity of the receptor that is desired to be retained, i.e., the ability to bind one or more ligands of interest.[0442]
• It is within the scope of the invention to have two or more exogenous proteins expressed within and preferentially displayed by minicells in order to achieve combined, preferable synergistic, therapeutic compositions. Similarly, two or more therapeutic minicell compositions are formulated into the same composition, or are administered during the same therapeutic minicell compositions (i.e., “cocktail” therapies). In other types of “cocktail” therapy, one or more therapeutic minicell compositions are combined or co-administered with one or more other therapeutic agents that are not minicell compositions such as, e.g., organic compounds, therapeutic proteins, gene therapy constructs, and the like.III.F. Minicells from L-form Eubacteria[0443]
• L-form bacterial strains may be used to prepare minicells and are preferred in some embodiments of the invention. L-form bacterial strains are mutant or variant strains, or eubacteria that have been subject to certain conditions, that lack an outer membrane, a cell wall, a periplasmic space and extracellular proteases. Thus, in L-form Eubacteria, the cytoplasmic membrane is the only barrier between the cytoplasm and its surrounding environment. For reviews, see Grichko, V. P., et al. 1999. The Potential of L-Form Bacteria in Biotechnology, Can. J. Chem. Engineering 77:973-977; and Gumpert J., et al. 1998 Use of cell wall-less bacteria (L-forms) for efficient expression and secretion of heterologous gene products. Curr Opin Biotechnol. 9:506-9.[0444]
• Segregation of minicells from L-form eubacterial parent cells allows for the generation of minicells that are at least partially deficient in barriers that lie outside of the cytoplasmic membrane, thus providing direct access to components displayed on the minicell membrane. Thus, depending on the strains and methods of preparation used, minicells prepared from L-form eubacterial parent cells will be similar if not identical to various forms of poroplasts, spheroplasts and/or protoplasts. Displayed components that are accessible in L-form minicells include, but are not limited to, lipids, small molecules, proteins, sugars, nucleic acids and/or moieties that are covalently or non-covalently associated with the cytoplasmic membrane or any component thereof.[0445]
• By way of non-limiting example, L-form Eubacteria that can be used in the methods of the invention include species of Escherichia, Streptomyces, Proteus, Bacillus, Clostridium, Pseudomonas, Yersinia, Salmonella, Enterococcus and Erwinia. See Onoda, T., et al. 1987. Morphology, growth and reversion in a stable L-form of[0446]Escherichia coliK12. J. Gen. Microbiol. 133:527-534; Inanova, E. H., et al. 1997. Effect ofEscherichia coliL-form cytoplasmic membranes on the interaction between macrophages and Lewis lung carcinoma cells: scanning electron microscopy. FEMS Immunol. Med. Microbiol. 17:27-36; Onoda, T., et al. 2000. Effects of calcium and calcium chelators on growth and morphology ofEscherichia coliL-form NC-7. J Bacteriol. 182:1419-1422; Innes, C. M., et al. 2001. Induction, growth and antibiotic production ofStreptomyces viridifaciensL-form bacteria. J Appl Microbiol. 90:301-308; Ferguson, C. M., et al. 2000. An ELISA for the detection ofBacillus subtilisL-form bacteria confirms their symbiosis in strawberry. Lett Appl Microbiol. 31:390-394; Waterhouse R. N., et al. 1994. An investigation of enumeration and DNA partitioning inBacillus subtilisL-form bacteria. J Appl Bacteriol. 77:497-503; Hoischen, C., et al. 2002. Novel bacterial membrane surface display system using cell wall-less L-forms ofProteus mirabilisandEscherichia coli.Appl. Environ. Microbiol. 68:525-531; Rippmann, J. F., et al. 1998. Procaryotic expression of single-chain variable-fragment (scFv) antibodies: secretion in L-forn cells ofProteus mirabilisleads to active product and overcomes the limitations of periplasmic expression inEscherichia coli.Appl. Environ. Microbiol. 64:4862-4869; Mahony, D. E., et al. 1988. Transformation ofClostridium perfringensL forms with shuttle plasmid DNA. Appl. Environ. Microbiol. 54:264-267); Kurona, M., et al. 1983. Intergenus cell fusions between L-form cells ofPseudomonas aeruginosaandEscherichia coli.Biken. J. 26:103-111; Ivanova, E., et al. 2000. Studies of the interactions of immunostimulated macrophages andYersinia enterocoliticaO:8. Can. J. Microbiol. 46:218-228; Allan, E. J., et al. 1993. Growth and physiological characteristics ofBacillus subtilisL-forms. J. Appl. Bacteriol. 74:588-594; Allan, E. J. 1991. Induction and cultivation of a stable L-form ofBacillus subtilis.J. Appl. Bacteriol. 70:339-343; Nishikawa, F., et al. 1994. Protective capacity of L-formSalmonella typhimuriumagainst murine typhoid in C3H/HeJ mice. Microbiol. Immunol. 38:129-137; Kita, E., et al. 1993. Isolation of a cytotoxin from L-formSalmonella typhimurium.FEMS Microbiol. Lett. 109:179-184; Jass, J., et al. Growth and adhesion ofEnterococcus faeciumL-forms. FEMS Microbiol. Lett. 115:157-162; and U.S. Pat. No. 6,376,245.
• IV. Assaying Minicells[0447]
• IV.A. Efficiency of Minicell Production[0448]
• The level of minicell production will vary and may be evaluated using methods described herein. Relatively high levels of minicell production are generally preferred. Conditions in which about 40% of cells are achromosomal have been reported (see, e.g., Hassan et al., Suppression of initiation defects of chromosome replication in[0449]Bacillus subtilisdnaA and oriC-deleted mutants by integration of a plasmid replicon into the chromosomes, J Bacteriol 179:2494-502, 1997). Procedures for identifying strains that give high yields of minicells are known in the art; see, e.g., Clark-Curtiss and Curtiss III, Analysis of Recombinant DNA UsingEscherichira coliMinicells, Meth. Enzol. 101:347-362, 1983.
• Minicell production can be assessed by microscopic examination of late log-phase cultures. The ratio of minicells to normal cells and the frequency of cells actively producing minicells are parameters that increase with increasing minicell production.[0450]
• IV.B. Detecting Protein Synthesis in Minicells[0451]
• Methods for detecting and assaying protein production are known in the art. See, e.g., Clark-Curtiss and Curtiss III, Meth Enzol 101:347-362, 1983. As an exemplary procedure, transformed[0452]E. coliminicell-producing cells are grown in LB broth with the appropriate antibiotic overnight. The following day the overnight cultures are diluted 1:50 in fresh media, and grown at 37° C. to mid-log phase. If it is desired to eliminate whole cells, an antibiotic that kills growing (whole) cells but not quiescent cells (minicells) may be used. For example, in the case of cells that are not ampicillin resistant, ampicillin (100 mg per ml is added), and incubation is allowed to continue for about 2 more hrs. Cultures are then centrifuged twice at low speed to pellet most of the large cells. Minicells are pelleted by spinning 10 min at 10,000 rpm, and are then resuspended in M63 minimal media supplemented with 0.5% casamino acids, and 0.5 mM cAMP, or M9 minimal medium supplemented with 1 mM MgSO₄, 0.1 mM CaCl₂, 0.05% NaCl, 0.2% glucose, and 1 ng per ml thiamine. Labeled (³⁵S) methonine is added to the minicells for about 15 to about 90 minutes, and minicells are immediately collected afterwards by centrifugation for 10 min at 4° C. and 14,000 rpm. Cells are resuspended in 50 to 100 μg Laemmeli-buffer, and disrupted by boiling and vortexing (2 min for each step). Incorporation of³⁵S-methionine was determined by measuring the amount of radioactivity contained in 1 μl of the lysate after precipitation of proteins with trichloroacetic acid (TCA). Minicell lysates (50,000 to 100,000 cpm per lane) are subjected to PAGE on, e.g., 10% polyacrylamide gels in which proteins of known size are also run as molecular weight standards. Gels are fixed and images there of are generated by, e.g., autoradiography or any other suitable detection systems.
• IV.C. Evaluating the Therapeutic Potential of Minicells[0453]
• Various methods are used at various stages of development of a therapeutic minicell composition to estimate their therapeutic potential. As a non-limiting example, the therapeutic potential of minicells displaying a receptor is examined as follows.[0454]
• IV.C.1.Receptors[0455]
• The specificity of, rate of association of, rate of dissociation of, and/or stability of complexes resulting from, receptor binding to its ligand can be measured in vitro using methods known in the art.[0456]
• In the case of a sphingolipid binding receptor, such as an SIP receptor, the ligand (SIP) is detectably labeled so that the specificity of, rate of formation of, and degree of stability of complexes resulting from the ligand-receptor binding can be examined by measuring the degree and rate at which the labeled ligand is removed from solution due to its binding to minicells displaying the receptor. In order to avoid extraneous factors from influencing these experiments, they are carried out in buffered solutions that are as free of contaminating substances as possible. However, as is understood in the art, stabilizing agents such as BSA (bovine serum albumin) or protease inhibitors may be desirably included in these experiments. In a preferred environment, a sphingolipid binding receptor is the rat EDG-1, rat EDG-3, rat SCaMPER and human SCaMPER, the sequences of which are set forth herein.[0457]
• Minicell compositions that bind sphingolipids with the desired specificity are identified from the preceding experiments. Typically, studies of ligand-receptor binding then proceed to studies in which the binding capacity of promising minicell compositions is tested under in vitro conditions that are increasingly more representative of in vivo conditions. For example, binding experiments are carried out in the presence of sera or whole blood in order to determine the therapeutic potential of minicell compositions in the presence of compounds that are present within the circulatory system of an animal.[0458]
• IV.C.2.Molecular Sponge[0459]
• Minicell compositions can also be tested for their ability to bind and/or interanlize toxic compounds. The therapeutic potential of such capacity is evaluated using experiments in which detectably labeled derivatives of a toxic compound are present in the bloodstream of an anesthetized animal, which may a human. The blood of the animal is shunted out of the body and past a device that incorporates a minicell composition before being returned to the body. The device is constructed so that the blood contacts a semipermeable membrane that is in contact with the minicell composition. By “semipermeable” it is meant that certain agents can be freely exchanged across the membrane, whereas others are retained on one side of the membrane or the other. For example, the toxic compound of interest is able to cross the semipermeable membrane, whereas minicells and blood cells are separately retained in their respective compartments. Detectably labeled derivatives of the toxic compound are present in the bloodstream of the animal. The capacity of the minicells to take up the toxic compound corresponds with a reduction of the levels of detectably labeled material in the blood and an increase in detectably labeled material in the minicell composition.[0460]
• The above types of minicell-comprising compositions, devices, and procedures may be incorporated into ex vivo modalities such as ex vivo gene therapy and dialysis machines. An “ex vivo modality” is one in which a biological sample, such as a blood sample, is temporarily removed from an animal, altered through in vitro manipulation, and then returned to the body. In “ex vivo gene therapy,” cells in the sample from the animal are transformed with DNA in vitro and then returned to the body. A “dialysis machine” is a device in which a fluid such as blood of an animal is temporarily removed therefrom and processed through one or more physical, chemical, biochemical, binding or other processes designed to remove undesirable substances including but are not limited to toxins, venoms, overexpressed or overactive endogenous agents, and pathogens or molecules derived therefrom.[0461]
• Intraminicellular co-expression of a second molecule that is displayed on the surface of minicells, and which is a ligand for a binding moiety that is immobilized, can optionally be used in order to remove minicells from the sample before it is returned to the body. In the latter aspect, minicells that bind undesirable substances are preferably removed with the undesirable compound remaining bound to the minicells. Minicells that have been used for ex vivo gene therapy, but which have failed to deliver a nucleic acid to any cells in the sample, can be removed in a similar manner.[0462]
• IV. C.3. Minicell-Solubilized Receptors[0463]
• It is known in the art to use recombinant DNA technology to prepare soluble (hydrophilic) receptor fragments from receptors that bind a bioactive ligand. Unlike the native, membrane-bound receptor, which is relatively insoluble in water (hydrophobic), soluble receptor fragments can be formulated for therapeutic delivery using techniques that are known to have been used to formulate soluble agents.[0464]
• Typically, soluble receptor fragments are used to competitively inhibit the binding of the receptor to its ligand. That is, the soluble receptor fragments bind the ligand at the expense of the membrane-bound receptor. Because less of the ligand is bound to its receptor, the cellular response to the ligand is attenuated. Common cellular responses that are desirably attenuated include but are not limited to the uptake of an undesirable agent (e.g., a toxin, a pathogen, etc.) and activation of a signaling pathway having undesirable consequences (e.g., inflammation, apoptosis, unregulated growth, etc.).[0465]
• Preparing a soluble fragment derived from a receptor is not trivial. Typically, the three dimensional structure of the receptor is not known, and must be predicted based on homology with other receptors or by using software that predicts the tertiary structure of a polypeptide based on its amino acid sequence. Using the hypothetical structure of the receptor, a series of polypeptides are prepared that comprise amino acid sequences from the receptor but lack regions thereof that are thought to be membrane-anchoring or transmembrane domain(s) of the receptor. Some of the polypeptides prepared this way may be soluble, some may retain the binding activity of the receptor, and a few may have both characteristics. Members of the latter class of polypeptides are soluble receptor fragments, some of which may be amenable to development as a therapeutic or diagnostic agent.[0466]
• For any given receptor, there is always the possibility that none of the soluble fragments derived from the receptor will specifically bind its ligand with sufficient affinity as to be thereapeutically effective. Thus, in some instances, it may not be possible to prepare a receptor fragment that is both soluble and sufficiently biologically active.[0467]
• The minicells of the invention provide a “universal carrier” for receptors that allows the hydrophobic receptors to be solubilized in the sense that, although they remain associated with a membrane, the minicell is a small, soluble particle. That is, as an alternative to preparing a set of polypeptides to see which, if any of them, are water soluble receptor fragments, one may, using the teachings of the disclosure, prepare soluble minicells that display the receptor.[0468]
• IV.C.4.Reducing Toxicity[0469]
• For in vivo use of minicells for the purposes of eliciting an immune response or for therapeutic and diagnostic applications involving delivery of minicells to a human or to an anima, it may be useful to minimize minicell toxicity by using endotoxin-deficient mutants of parent cells. Without being limited to the following example, lipopolysaccharide (LPS) deficient[0470]E. colistrains could be conjugated with minicell producing cells to make parent cells lacking the endotoxin. LPS synthesis inE. coliincludes the lipid A biosynthetic pathway. Four of the genes in this pathway have now been identified and sequenced, and three of them are located in a complex operon which also contains genes involved in DNA and phospholipid synthesis. The rfa gene cluster, which contains many of the genes for LPS core synthesis, includes at least 17 genes. The rfb gene cluster encodes protein involved in O-antigen synthesis, and rfb genes have been sequenced from a number of serotypes and exhibit the genetic polymorphism anticipated on the basis of the chemical complexity of the O antigens (Schnaitman and Klena. 1993. Genetics of lipopolysaccharide biosynthesis in enteric bacteria. Microbiol. Rev. 57:655-82). When present alone or in combination the rfb and oms mutations cause alterations in the eubacterial membrane that make it more sensitive to lysozyme and other agents used to process minicells. Similarly, the rfa (Chen, L., and W. G. Coleman Jr. 1993. Cloning and characterization of theEscherichia coliK-12 rfa-2 (rfaC) gene, a gene required for lipopolysaccharide inner core synthesis. J. Bacteriol. 175:2534-2540), lpcA (Brooke, J. S., and M. A. Valvano. 1996. Biosynthesis of inner core lipopolysaccharide in enteric bacteria identification and characterization of a conserved phosphoheptose isomerase. J. Biol. Chem. 271:3608-3614), and lpcB (Kadrman, J. L., et al. 1998. Cloning and overexpression of glycosyltransferases that generate the lipopolysaccharide core ofRhizobium leguminosarum.J. Biol. Chem. 273:26432-26440) mutations, when present alone or in combination, cause alterations in lipopolysaccharides in the outer membrane causing cells to be more sensitive to lysozyme and agents used to process minicells. In addition, such mutations can be used to reduce the potential antigenicity and/or toxicity of minicells.
• Minicell-producing cells may comprise mutations that augment preparative steps. For example, lipopolysaccharide (LPS) synthesis in[0471]E. coliincludes the lipid A biosynthetic pathway. Four of the genes in this pathway have now been identified and sequenced, and three of them are located in a complex operon that also contains genes involved in DNA and phospholipid synthesis. The rfa gene cluster, which contains many of the genes for LPS core synthesis, includes at least 17 genes. The rfb gene cluster encodes protein involved in O-antigen synthesis, and rfb genes have been sequenced from a number of serotypes and exhibit the genetic polymorphism anticipated on the basis of the chemical complexity of the O antigens. See Schnaitman and Klena, Genetics of lipopolysaccharide biosynthesis in enteric bacteria, Microbiol. Rev. 57:655-82, 1993. When present, alone, or in combination, the rfb and oms mutations cause alterations in the eubacterial membrane that make it more sensitive to lysozyme and other agents used to process minicells. Similarly, the rfa (Chen, L., and W. G. Coleman Jr. 1993. Cloning and characterization of theEscherichia coliK-12 rfa-2 (rfaC) gene, a gene required for lipopolysaccharide inner core synthesis. J. Bacteriol. 175:2534-2540), lpcA (Brooke, J. S., and M. A. Valvano. 1996. Biosynthesis of inner core lipopolysaccharide in enteric bacteria identification and characterization of a conserved phosphoheptose isomerase. J. Biol. Chem. 271:3608-3614), and lpcB (Kadrman, J. L., et al. 1998. Cloning and overexpression of glycosyltransferases that generate the lipopolysaccharide core ofRhizobium leguminosarum.J. Biol. Chem. 273:26432-26440) mutations, when present alone or in combination, cause alterations in lipopolysaccharides in the outer membrane causing cells to be more sensitive to lysozyme and agents used to process minicells. In addition, such mutations can be used to reduce the potential antigenicity and/or toxicity of minicells.
• V. Genetic Expression in Minicells[0472]
• Various minicells of the invention use recombinant DNA expression systems to produce a non-eubacterial protein, which may be a membrane protein that is preferably “displayed” on the surface of minicells, a membrane protein that projects portions not associtiated with a membrane towards the interior of a minicell, or a soluble protein present in the exterior of the minicells. By “displayed” it is meant that a protein is present on the surface of a cell (or minicell) and is thus in contact with the external environment of the cell. Non-limiting examples of displayed exogenous proteins of the invention include mammalian receptors and fusion proteins comprising one or more transmembrane domains. In other aspects of the invention, minicells use expression elements to produce bioactive nucleic acids from templates therefor.[0473]
• V.A. Expression Systems[0474]
• In vivo and in vitro protein expression systems provide a variety of techniques that allow scientists to transcribe and translate amino acid polypeptides proteins from recombinant DNA templates (Kaufman, Overview of vector design for mammalian gene expression. Mol Biotechnol, 2001. 16: 151-160; and Kozak, Initiation of translation in prokaryotes and eukaryotes. Gene, 1999. 234: 187-208).[0475]
• Although minicells are virtually depleted of chromosomal DNA (Tudor et al., Presence of nuclear bodies in some minicells of[0476]Escherichia coli.J Bacteriol, 1969. 98: 298-299), it has been reported that minicells have all the elements required to express nucleotide sequences that are present in episomal expression elements therein (Levy, Very stable prokaryote messenger RNA in chromosomelessEscherichia coliminicells. Proc Natl Acad Sci USA, 1975. 72: 2900-2904; Hollenberg et al., Synthesis of high molecular weight polypeptides inEscherichia coliminicells directed by clonedSaccharomyces cerevisiae2-micron DNA. Gene, 1976. 1: 33-47; Crooks et al., Transcription of plasmid DNA inEscherichia coliminicells. Plasmid, 1983. 10: 66-72; Clark-Curtiss, Analysis of recombinant DNA usingEscherichia coliminicells. Methods Enzymol, 1983. 101: 347-362).
• Preferred expression vectors and constructs according to the invention are episomal genetic elements. By “episomal” it is meant that the expression construct is not always linked to a cell's chromosome but may instead be retained or maintained in host cells as a distinct molecule entity. Minicells can retain, maintain and express episomal expression constructs such as, e.g., plasmids, bacteriophage, viruses and the like (Crooks et al., Plasmin 10:66-72, 1983; Clark-Curtiss, Methods Enzymology 101:347-62, 1983; Witkiewicz et al., Acta. Microbiol. Pol. A 7:21-24, 1975; Ponta et al., Nature 269:440-2, 1977). By “retained” it is meant that the episomal expression construct is at least temporarily present and expressed in a host parent cell and/or minicell; by “maintained” it is meant that the episomal expression construct is capable of autonomous replication within a host parent cell and/or minicell. In the context of episomal elements, the term “contained” encompasses both “retained” and “maintained.” A preferred type of an episomal element according to the invention is one that is always an extrachromocomal element, or which is part of a chromosome but becomes an extrachromosomal element before or during minicell production.[0477]
• The fact that minicells do not contain chromosomal DNA but do contain episomal expression elements, such as plasmids, that can be used as templates for RNA synthesis means that the only proteins that are actively produced in minicells are those that are encoded by the expression elements that they contain. Minicell-producing[0478]E. colicells can be made competent and transformed with expression elements that direct the expression of proteins encoded by the expression elements. An expression element segregates into minicells as they are produced. In isolated minicells that contain expression elements, there is a single DNA template RNA for transcription. Therefore, the only nucleic acids and proteins that are actively produced (expressed) by minicells are those that are encoded by sequences on the expression vector. In the context of the invention, sequences that encode amino acid sequences are designated “open reading frames” or “ORFs.” One feature of minicell expression systems of interest as regards the present invention is that endogenous (i.e., chromosomally located) genes are not present and are thus not expressed, whereas genes present on the episomal element are expressed (preferably over-expressed) in the minicells. As a result, the amount of endogenous proteins, including membrane proteins, decreases as the minicells continue to express genes located on episomal expression constructs.
• The minicell system can reduce or eliminate undesirable features associated with the transcription and translation of endogenous proteins from the[0479]E. colichromosome. For example, expression of proteins in minicell systems results in low background signal (“noise”) when radiolabeled proteins produced using recombinant DNA technology (Jannatipour et al., Translocation of Vibrio Harveyi N,N′-DIacetylchitobiase to the outer membrane ofEscherichia coli.J. Bacteriol, 1987. 169: 3785-3791). A high background signal can make it difficult to detect a protein of interest. In whole cellE. colisystems, endogenous proteins (encoded by the bacterial chromosome) are labeled as well as the protein(s) encoded by the expression element; whereas, in minicell systems, only the proteins encoded by the expression element in the minicells are labeled.
• There are a variety of proteins, both eubacterial and eukaryotic, that have been expressed from plasmid DNA in minicells (Clark-Curtiss, Methods Enzymal, 101:347-362, 1983). Some examples of proteins and nucleic acids that have been expressed in minicells include the Kdp-ATPase of[0480]E. coli(Altendorf et al., Structure and function of the Kdp-ATPase ofEscherichia coli.Acta Physiol Scand, 643: 137-146, 1998); penicillin binding proteins aplha and gamma (Davies et al., Prediction of signal sequence-dependent protein translocation in bacteria: Assessment of theEscherichia coliminicell system. Biochem Biophys Res Commun, 150: 371-375, 1988); cell surface antigens ofPolyromaonas gingivalas(Rigg et al., The molecular cloning, nucleotide sequence and expression of an antigenic determinant fromPorphyromonas gingivalis.Arch Oral Biol, 45:41-52, 2000); trkG integral membrane protein ofE. coli(Schlosser et al., Subcloning, Nucleotide sequence, and expression of trkG, a gene that encodes an integral membrane protein involved in potassium uptake via the Trk system ofEscherichia coli.J. Bacteriol, 173:3170-3176, 1991); the 34 kDa antigen ofTreponema pallidum(Swancutt et al., Molecular characterization of the pathogen-specific, 34-kilodalton membrane immunogen ofTreponema pallidum.Infect Immun, 57:3314-23, 1989); late proteins of bacteriophage MB78 (Colla et al., IUBMB Life 48:493-497, 1999); uncharacterisized DNA fromXenopus laevis(Cohen and Boyer, U.S. Pat. No. 4,237,224, which issued Dec. 2, 1980); the onc gene v-fos (MacConnell and Verman, Expression of FBJ-MSV oncogene (fos) product in bacteria, 131(2) Virology 367 1983); interferon (Edge et al., Chemical synthesis of a human inteferon-alpha 2 gene and its expression inEscherichia coli,Nucleic Acids Res. 11:6419, 1983); bovine growth hormone (Rosner et al., Expression of a cloned bovine growth hormone gene inEscherichia coliminicells, Can. J. Biochem. 60:521-4, 1982); gastroitestinal hormone (Suzuki et al., Production inEscherichia coliof biologically active secretin, a gastroninstestinal hormone, Proc. Natl. Acad. Sci. USA 79:2475, 1982); and archeabacterial proteins (Lienard and Gottschalk, Cloning, sequencing and expression of the genes encoding the sodium translocating N-methyltetrahydromethanopterin: coenzyme M methyltransferase of the methylotrohic archaeon Methanosarcina mazei Göl, 425 FEBS Letters 204, 1998; and Lemker et al., Overproduction of a functional A1 ATPase from the archaeon Methanosarcina mazei G1 inEscherichia coli,European Journal of Biochemistry 268:3744, 2001).
• V.B. Modulating Genetic Expression in Minicells[0481]
• Gene expression in minicells, and/or in minicell-producing (parent) cells, involves the coordinated activity of a variety of expression factors,regulatory elements and expression sequences. Any of these may be modified to alter the extent, timing or regulation of expression of a gene of interest in minicells and/or their parent cells. Often, the goal of the manipulations is to increase the efficiency of protein production in minicells. However, increased expression may, in some instances, desirably include increased or “tight” negative regulation. This may reduce or eliminate selective pressure created by toxic gene products, and allow for functional expression in a controlled fashion by removing the negative regulation and/or inducing expression of the gene product at a preselected time. By way of non-limiting example, these techniques may include modification or deletion of endogenous gene(s) from which their respective gene product decreases the induction and expression efficiency of a desired protein in the parent cell prior to minicell formation and/or the segregated minicell. By way of non-limiting example, these protein components may be the enzymes that degrade chemical inducers of expression, proteins that have a dominant negative affect upon a positive regulatory elements, proteins that have proteolytic activity against the protein to be expressed, proteins that have a negative affect against a chaperone that is required for proper activity of the expressed protein, and/or this protein may have a positive effect upon a protein that either degrades or prevents the proper function of the expressed protein. These gene products that require deletion or modification for optimal protein expression and/or function may also be antisense nucleic acids that have a negative affect upon gene expression.[0482]
• VI. Fusion (Chimeric) Proteins[0483]
• In certain aspects of the invention, a fusion protein is expressed and displayed by minicells. One class of fusion proteins of particular interest are those that are displayed on the surface of minicells, e.g., fusion proteins comprising one or more transmembrane domains. Types of displayed fusion proteins of particular interest are, by way of non-limiting example, those that have an extracellular domain that is a binding moiety or an enzymatic moiety. By way of non-limiting example, the fusion protein ToxR-PhoA has been expressed in and displayed on the surface of minicells. The ToxR-PhoA fusion protein comprises a polypeptide corresponding to the normally soluble enzyme, alkaline phosphatase, anchored to the minicell membrane by the single transmembrane domain of ToxR (see the Examples). The fusion protein retains the activity of the enzyme in the context of the minicell membrane in which it is bound. Nearly all of the fusion protein is oriented so that the enzyme's catalytic domain is displayed on the outer surface of the minicell.[0484]
• VI.A. Generation of Fusion Proteins[0485]
• Polypeptides, which are polymers of amino acids, are encoded by another class of molecules, known as nucleic acids, which are polymers of structural units known as nucleotides. In particular, proteins are encoded by nucleic acids known as DNA and RNA (deoxyribonucleic acid and ribonucleic acid, respectively).[0486]
• The nucleotide sequence of a nucleic acid contains the “blueprints” for a protein. Nucleic acids are polymers of nucleotides, four types of which are present in a given nucleic acid. The nucleotides in DNA are adenine, cytosine and guanine and thymine, (represented by A, C, G, and T respectively); in RNA, thymine (T) is replaced by uracil (U). The structures of nucleic acids are represented by the sequence of its nucleotides arranged in a 5′ (“5 prime”) to 3′ (“3 prime”) direction, e.g.,[0487]
• 5′-A-T-G-C-C-T-A-A-A-G-C-C-G-C-T-C-C-C-T-C-A-3′
• In biological systems, proteins are typically produced in the following manner. A DNA molecule that has a nucleotide sequence that encodes the amino acid sequence of a protein is used as a template to guide the production of a messenger RNA (mRNA) that also encodes the protein; this process is known as transcription. In a subsequent process called translation, the mRNA is “read” and directs the synthesis of a protein having a particular amino acid sequence.[0488]
• Each amino acid in a protein is encoded by a series of three contiguous nucleotides, each of which is known as a codon. In the “genetic code,” some amino acids are encoded by several codons, each codon having a different sequence; whereas other amino acids are encoded by only one codon sequence. An entire protein (i.e., a complete amino acid sequence) is encoded by a nucleic acid sequence called a reading frame. A reading frame is a continuous nucleotide sequence that encodes the amino acid sequence of a protein; the boundaries of a reading frame are defined by its initiation (start) and termination (stop) codons.[0489]
• The process by which a protein is produced from a nucleic acid can be diagrammed as follows:[0490]

  DNA	(A-T-G) - (A-A-G) - (C-C-G) - (C-T-C) - (C-C-T) - . . . (etc.)
  	↓ Transcription
  RNA	(A-U-G) - (A-A-G) - (C-C-G) - (C-U-C) - (C-C-U) - . . . (etc.)
  	↓ Translation
  Protein	Met - Pro - Lys - Ala - Ala - . . . (etc.)

• A chimeric reading frame encoding a fusion protein is prepared as follows. A “chimeric reading frame” is a genetically engineered reading frame that results from the fusion of two or more normally distinct reading frames, or fragments thereof, each of which normally encodes a separate polypeptide. Using recombinant DNA techniques, a first reading frame that encodes a first amino acid sequence is linked to a second reading frame that encodes a second amino acid sequence in order to generate a chimeric reading frame. Chimeric reading frames may also include nucleotide sequences that encode optional fusion protein elements (see below).[0491]
• A hypothetical example of a chimeric reading frame created from two normally separate reading frames is depicted in the following flowchart.[0492]
• First Open Reading Frame and “Protein-1”:[0493]

  DNA-1	(A-T-G) - (A-A-G) - (C-C-G) - (C-T-C) - (C-C-T) - . . . (etc.)
  	↓ Transcription
  RNA-1	(A-U-G) - (A-A-G) - (C-C-G) - (C-U-C) - (C-C-U) - . . . (etc.)
  	↓ Translation
  Protein-1	Met - Pro - Lys - Ala - Ala - . . . (etc.)

• Second Open Reading Frame and “Protein-2”:[0494]

  DNA-2	(T-G-G) - (G-T-T) - (A-C-T) - (C-A-C) - (T-C-A) - . . . (etc.)
  	↓ Transcription
  RNA-2	(U-G-G) - (A-U-U) - (A-C-U) - (C-A-C) - (U-C-A) - . . . (etc.)
  	↓ Translation
  Protein-2	Trp - Val - Thr - His - Ser -. . . (etc.)

• Chimeric Reading Frame that Encodes a Fusion Protein Having Sequences from Protein-1 and Protein-2:[0495]

  DNA-Chimera	(A-T-G) - (A-A-G) - (C-C-G) - (C-A-C) - (T-C-A) - (etc.)
  	↓ Transcription
  RNA-Chimera	(A-U-G) - (A-A-G) - (C-C-G) - (C-A-C) - (U-C-A) - (etc.)
  	↓ Translation
  Fusion Protein	Met - Pro - Lys -His - Ser -(etc.)

• In order for a chimeric reading frame to be functional, each normally distinct reading frame therein must be fused to all of the other normally distinct reading frames in a manner such that all of the reading frames are in frame with each other. By “in frame with each other” it is meant that, in a chimeric reading frame, a first nucleic acid having a first reading frame is covalently linked to a second nucleic acid having a second reading frame in such a manner that the two reading frames are “read” (translated) in register with each other. As a result, the chimeric reading frame encodes one extended amino acid sequence that includes the amino acid sequences encoded by each of the normally separate reading frames. A fusion protein is thus encoded by a chimeric reading frame.[0496]
• The fusion proteins of the invention are used to display polypeptides on minicells. The fusion proteins comprise (1) at least one polypeptide that is desired to be displayed by minicells (a “displayed polypeptide”) and (2) at least one membrane polypeptide, e.g., a transmembrane or a membrane anchoring domain. For various aspects of the invention, optional fusion protein elements, as defined herein, may also be included if required or desired.[0497]
• VI.B. Optional Fusion Protein Elements[0498]
• The fusion proteins of the invention may optionally comprise one or more non-biologically active amino acid sequences, i.e., optional fusion protein elements. Such elements include, but are not limited to, the following optional fusion protein elements. It is understood that a chimeric reading frame will include nucleotide sequences that encode such optional fusion protein elements, and that these nucleotide sequences will be positioned so as to be in frame with the reading frame encoding the fusion protein. Optional fusion protein elements may be inserted between the displayed polypeptide and the membrane polypeptide, upstream or downstream (amino proximal and carboxy proximal, respectively) of these and other elements, or within the displayed polypeptide and the membrane polypeptide. A person skilled in the art will be able to determine which optional element(s) should be included in a fusion protein of the invention, and in what order, based on the desired method of production or intended use of the fusion protein.[0499]
• Detectable polypeptides are optional fusion protein elements that either generate a detectable signal or are specifically recognized by a detectably labeled agent. An example of the former class of detectable polypeptide is green fluorescent protein (GFP). Examples of the latter class include epitopes such as a “His tag” (6 contiguous His residues, a.k.a. 6×His), the “FLAG tag” and the c-myc epitope. These and other epitopes can be detected using labeled antibodies that are specific for the epitope. Several such antibodies are commercially available.[0500]
• Attachment (support-binding) elements are optionally included in fusion proteins and can be used to attach minicells displaying a fusion protein to a preselected surface or support. Examples of such elements include a “His tag,” which binds to surfaces that have been coated with nickel; streptavidin or avidin, which bind to surfaces that have been coated with biotin or “biotinylated” (see U.S. Pat. No. 4,839,293 and Airenne et al., Protein Expr. Purif. 17:139-145, 1999); and glutathione-s-transferase (GST), which binds to surfaces coated with glutathione (Kaplan et al., Protein Sci. 6:399-406, 1997; U.S. Pat. No. 5,654,176). Polypeptides that bind to lead ions have also been described (U.S. Pat. No. 6,111,079).[0501]
• Spacers (a.k.a. linkers) are amino acid sequences that are optionally included in a fusion protein in between other portions of a fusion protein (e.g., between the membrane polypeptide and the displayed polypeptide, or between an optional fusion protein element and the remainder of the fusion protein). Spacers can be included for a variety of reasons. For example, a spacer can provide some physical separation between two parts of a protein that might otherwise interfere with each other via, e.g., steric hindrance. The ability to manipulate the distance between the membrane polypeptide and the displayed polypeptide allows one to extend the displayed polypeptide to various distances from the surface of minicells.[0502]
• VI.C. Interactions with Receipient Cells[0503]
• Many Gram-negative pathogens use a type III secretion machine to translocate protein toxins across the bacterial cell envelope (for a review, see Cheng L W, Schneewind O. Type III machines of Gram-negative bacteria: delivering the goods. Trends Microbiol 2000 May;8(5):214-20). For example, pathogenic Yersinia spp. export over a dozen Yop proteins via a type III mechanism, which recognizes secretion substrates by signals encoded in yop mRNA or chaperones bound to unfolded Yop proteins. A 70-kb virulence plasmid found in pathogenic Yersinia spp. to survive and multiply in the lymphoid tissues of the host. The virulence plasmid encodes the Yop virulon, an integrated system allowing extracellular bacteria to inject bacterial proteins into cells. The Yop virulon comprises a variety of Yop proteins and a dedicated type III secretion apparatus, called Ysc (for a review, see Cornelis G R, Boland A, Boyd A P, Geuijen C, Iriarte M, Neyt C, Sory M P, Stainier I. The virulence plasmid of Yersinia, an antihost genome. Microbiol Mol Biol Rev 1998 62(4):1315-52).[0504]
• VII. Minicell Display[0505]
• Included in the design of the invention is the use of minicells to express and display soluble or membrane-bound protein libraries to identify a soluble or membrane-bound protein that binds a known ligand or to identify proteins (e.g. orphan receptors) for which the known ligand or substrate is not known but for which a reporter could be engineered into the minicell that would signal the presence of the encoded protein. In the preferred embodiment of the invention, this ‘minicell display’ technique is analogous to phage display for the purpose of identifying genes that encode receptor-like or antibody-like proteins against known ligand. This approach will allow identification of an unknown receptor protein for which a known ligand has affinity. These known ligands may have been identified as having a pharmacological, biological, or other effect without knowledge of the site of effect. In these cases the knowledge of receptor will allow basic research to understand the molecular and/or physiological response and permit directed modification of the ligand for better pharmacological or biological response or modification of the receptor for employment in ligand-binding applications. In another non-limiting embodiment of the invention, the ligand need not be known but some general characteristic of the protein would be.[0506]
• For purposes of this application, soluble or membrane-bound protein libraries may be constructed by random cloning of DNA fragments or directed cloning using reverse transcriptase polymerase chain reaction (RT-PCR). In either method, DNA fragments may be placed under the regulation of any regulatory element listed in section II.B. on any plasmid or chromosomal construct. In the case of soluble protein receptors, they will be fused to form a chimeric protein with a known transmembrane domain (TMD), e.g. the TMD from the toxR gene product. Upon induction of the soluble or membrane-bound protein library, minicells, minicell protoplasts, or minicell poroplasts (as the experiment requires) will be mixed with the known ligand. Without being limited to the following example, screening could be accomplished by first labeling the known ligand with a molecular flourophore, e.g. TAMRA, FTC, or in some cases a fluorescent protein, e.g. GFP. A positive interaction between the minicells displaying the receptor for the labeled ligand will be identified and separated from the library population by fluorescent-activated cell sorting (FACS). Isolated, positive receptor-ligand interactions will be identified by PCR amplification, subcloned into a clean background, and sequenced using plasmid-specific oligonucleotides. Subcloned proteins will be re-screened for interaction with the labeled ligand, and their binding patterns characterized.[0507]
• Positive interacting receptor proteins may be employed in mutagenesis or other directed evolutionary process to improve or decrease the binding affinity to the ligand. In another application, the receptor-ligand pair may be further employed in a screening process to identify new compounds that may interfere with the interaction. Thus, using a known substance to identify the receptor and the identified receptor-ligand pair to identify other interfering compounds. Chimeric-soluble or membrane-bound protein libraries may be screened versus a protein-array chip that presents a variety of known protein compounds or peptide variations. In this application, the minicell, minicell protoplast, or minicell poroplast will also contain a label, signaling component, and/or antigen recognizable by an antibody for identification of a positive interaction on the protein chip array. Other approaches for identification may include packaged fluorescent molecules or proteins that are constitutively produced, induced by the positive interaction with the ligand, or regulated by a regulatory element described in section II.B.[0508]
• In a preferred embodiment of the invention, cDNA libraries could be constructed from isolated B-cells, activated B-cell or T-cells for the purpose of identifying receptors or antibodies that are encoded by these cells of the immune system. In a non-limiting example, a small molecule could be used to immunize an experimental animal (e.g., rat, mouse, rabbit), the spleen could be removed, or blood could be drawn and used as a source of mRNA. Reverse transcription reactions could then be used to construct a cDNA library that would eventually be transformed into the minicell parent bacteria, as described above. The minicells would then be isolated, induced and subjected to FACS analysis with subsequent amplification and sequencing of the cDNA fragment of interest (see above). The PCR-amplified plasmid-containing cDNA fragment encoding the “receptor” or “antibody” of interest would be ready for transformation and expression in the minicell context for diagnostic, therapeutic research or screening applications of the invention.[0509]
• In a related, non-limiting embodiment of the invention, minicells expressing a particular antigen (e.g., protein, carbohydrate, small molecule, lipid) on their surfaces (described elsewhere in this application) are used to generate an immunogenic response. The advantages of presenting an antigen on the surfaces of minicells are that the minicells themselves may be an adjuvant that stimulates the immune response, particularly if administered subcutaneously (SC) or intramuscularly (IM). Moreover, the minicells are not readily eliminated by the renal system and are present in the circulatory system of an immunized animal for a longer time. In addition, small molecules could be tethered to the minicell in a way that presents the desired moiety of the molecule. Animals are presented with minicell-based immunogens, and the antibodies produced in the animals are prepared and used in therapeutic, diagnostic, research and screening applications. Although this aspect of the invention may be used to make antibodies to any molecule displayed on their surface, the extracellular domains of membrane proteins are of particular interest.[0510]
• Minicell display could be used to identify orphan receptors or other proteins for which a ligand or substrate is not known. As a non-limiting example, orphan G protein coupled receptors (GPCRs) or novel RNA and DNA polymerases could be identified from organisms living in extreme environments. A cDNA library could be is constructed from an organism and expressed in minicells that co-express a reporter system that indicates the presence of the novel protein. In a non-limiting example of GPCRs, the minicells used for minicell display are engineered to express a G-protein in a manner that would signal an interaction with the orphan GPCR.[0511]
• VIII. Aptamers[0512]
• Traditionally, techniques for detecting and purifying target molecules have used polypeptides, such as antibodies, that specifically bind such targets. While nucleic acids have long been known to specifically bind other nucleic acids (e.g., ones having complementary sequences), aptamers (i.e., nucleic acids that bind non-nucleic target molecules) have been disclosed. See, e.g., Blackwell et al., Science (1990) 250:1104-1110; Blackwell et al., Science (1990) 250:1149-1152; Tuerk et al., Science (1990) 249:505-510; Joyce, Gene (1989) 82:83-87; and U.S. Patent 5,840,867 entitled “Aptamer analogs specific for biomolecules”.[0513]
• As applied to aptamers, the term “binding” specifically excludes the “Watson-Crick”-type binding interactions (i.e., A:T and G:C base-pairing) traditionally associated with the DNA double helix. The term “aptamer” thus refers to a nucleic acid or a nucleic acid derivative that specifically binds to a target molecule, wherein the target molecule is either (i) not a nucleic acid, or (ii) a nucleic acid or structural element thereof that is bound through mechanisms other than duplex- or triplex-type base pairing. Such a molecule is called a “non-nucleic molecule” herein.[0514]
• VIII.A. Structures of Nucleic Acids[0515]
• “Nucleic acids,” as used herein, refers to nucleic acids that are isolated a natural source; prepared in vitro, using techniques such as PCR amplification or chemical synthesis; prepared in vivo, e.g., via recombinant DNA technology; or by any appropriate method. Nucleic acids may be of any shape (linear, circular, etc.) or topology (single-stranded, double-stranded, supercoiled, etc.). The term “nucleic acids” also includes without limitation nucleic acid derivatives such as peptide nucleic acids (PNA's) and polypeptide-nucleic acid conjugates; nucleic acids having at least one chemically modified sugar residue, backbone, internucleotide linkage, base, nucleoside, or nucleotide analog; as well as nucleic acids having chemically modified 5′ or 3′ ends; and nucleic acids having two or more of such modifications. Not all linkages in a nucleic acid need to be identical.[0516]
• Nucleic acids that are aptamers are often, but need not be, prepared as oligonucleotides. Oligonucleotides include without limitation RNA, DNA and mixed RNA-DNA molecules having sequences of lengths that have minimum lengths of 2, 4, 6, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24 or 25 nucleotides, and maximum lengths of about 100, 75, 50, 40, 25, 20 or 15 or more nucleotides, irrespectively. In general, a minimum of 6 nucleotides, preferably 10 nucelotides, more preferably 14 to 20 nucleotides, is necessary to effect specific binding.[0517]
• In general, the oligonucleotides may be single-stranded (ss) or double-stranded (ds) DNA or RNA, or conjugates (e.g., RNA molecules having 5′ and 3′ DNA “clamps”) or hybrids (e.g., RNA:DNA paired molecules), or derivatives (chemically modified forms thereof). However, single-stranded DNA is preferred, as DNA is often less labile than RNA. Similarly, chemical modifications that enhance an aptamer's specificity or stability are preferred.VIII.B. Chemical Modifications of Nucleic Acids[0518]
• Chemical modifications that may be incorporated into aptamers and other nucleic acids include, with neither limitation nor exclusivity, base modifications, sugar modifications, and backbone modifications.[0519]
• Base modifications: The base residues in aptamers may be other than naturally occurring bases (e.g., A, G, C, T, U, 5MC, and the like). Derivatives of purines and pyrimidines are known in the art; an exemplary but not exhaustive list includes aziridinylcytosine, 4-acetylcytosine, 5-fluorouracil, 5-bromouracil, 5-carboxymethylaminomethyl-2-thiouracil, 5-carboxymethylaminomethyluracil, inosine, N6-isopentenyladenine, 1-methyladenine, 1-methylpseudouracil, 1-methylguanine, 1-methylinosine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-methylcytosine (5MC), N6-methyladenine, 7-methylguanine, 5-methylaminomethyluracil, 5-methoxyaminomethyl-2-thiouracil, beta-D-mannosylqueosine, 5-methoxyuracil, 2-methylthio-N-6-isopentenyladenine, uracil-5-oxyacetic acid methylester, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil, 5-methyluracil, uracil-5-oxyacetic acid, and 2,6-diaminopurine. In addition to nucleic acids that incorporate one or more of such base derivatives, nucleic acids having nucleotide residues that are devoid of a purine or a pyrimidine base may also be included in aptamers.[0520]
• Sugar modifications: The sugar residues in aptamers may be other than conventional ribose and deoxyribose residues. By way of non-limiting example, substitution at the 2′-position of the furanose residue enhances nuclease stability. An exemplary, but not exhaustive list, of modified sugar residues includes 2′ substituted sugars such as 2′-O-methyl-, 2′-O-alkyl, 2′-O-allyl, 2′-S-alkyl, 2′-S-allyl, 2′-fluoro-, 2′-halo, or 2′-azido-ribose, carbocyclic sugar analogs, alpha-anomeric sugars, epimeric sugars such as arabinose, xyloses or lyxoses, pyranose sugars, furanose sugars, sedoheptuloses, acyclic analogs and abasic nucleoside analogs such as methyl riboside, ethyl riboside or propylriboside.[0521]
• Backbone modifications: Chemically modified backbones include, by way of non-limiting example, phosphorothioates, chiral phosphorothioates, phosphorodithioates, phosphotriesters, aminoalkylphosphotriesters, methyl and other alkyl phosphonates including 3′-alkylene phosphonates and chiral phosphonates, phosphinates, phosphoramidates including 3′-amino phosphoramidate and aminoalkylphosphoramidates, thionophosphoramidates, thionoalkylphosphonates, thionoalkylphosphotriesters, and boranophosphates having normal 3′-5′ linkages, 2′-5′ linked analogs of these, and those having inverted polarity wherein the adjacent pairs of nucleoside units are linked 3′-5′ to 5′-3′ or 2′-5′ to 5′-2′. Chemically modified backbones that do not contain a phosphorus atom have backbones that are formed by short chain alkyl or cycloalkyl internucleoside linkages, mixed heteroatom and alkyl or cycloalkyl internucleoside linkages, or one or more short chain heteroatomic or heterocyclic internucleoside linkages, including without limitation morpholino linkages; siloxane backbones; sulfide, sulfoxide and sulfone backbones; formacetyl and thioformacetyl backbones; methylene formacetyl and thioformacetyl backbones; alkene containing backbones; sulfamate backbones; methyleneimino and methylenehydrazino backbones; sulfonate and sulfonamide backbones; and amide backbones.[0522]
• VIII.C. Preparation and Identification of Aptamers[0523]
• In general, techniques for identifying aptamers involve incubating a preselected non-nucleic target molecule with mixtures (2 to 50 members), pools (50 to 5,000 members) or libraries (50 or more members) of different nucleic acids that are potential aptamers under conditions that allow complexes of target molecules and aptamers to form. By “different nucleic acids” it is meant that the nucleotide sequence of each potential aptamer may be different from that of any other member, that is, the sequences of the potential aptamers are random with respect to each other. Randomness can be introduced in a variety of manners such as, e.g., mutagenesis, which can be carried out in vivo by exposing cells harboring a nucleic acid with mutagenic agents, in vitro by chemical treatment of a nucleic acid, or in vitro by biochemical replication (e.g., PCR) that is deliberately allowed to proceed under conditions that reduce fidelity of replication process; randomized chemical synthesis, i.e., by synthesizing a plurality of nucleic acids having a preselected sequence that, with regards to at least one position in the sequence, is random. By “random at a position in a preselected sequence” it is meant that a position in a sequence that is normally synthesized as, e.g., as close to 100% A as possible (e.g., 5′-C-T-T-A-G-T-3′) is allowed to be randomly synthesized at that position (C-T-T-N-G-T, wherein N indicates a randomized position where, for example, the synthesizing reaction contains 25% each of A,T,C and G; or x% A, w% T, y% C and z%G, wherein x+w+y+z=100. In later stages of the process, the sequences are increasingly less randomized and consensus sequences may appear; in any event, it is preferred to ultimately obtain an aptamer having a unique nucleotide sequence.[0524]
• Aptamers and pools of aptamers are prepared, identified, characterized and/or purified by any appropriate technique, including those utilizing in vitro synthesis, recombinant DNA techniques, PCR amplification, and the like. After their formation, target:aptamer complexes are then separated from the uncomplexed members of the nucleic acid mixture, and the nucleic acids that can be prepared from the complexes are candidate aptamers (at early stages of the technique, the aptamers generally being a population of a multiplicity of nucleotide sequences having varying degrees of specificity for the target). The resulting aptamer (mixture or pool) is then substituted for the starting apatamer (library or pool) in repeated iterations of this series of steps. When a limited number (e.g., a pool or mixture, preferably a mixture with less than 100 members, more preferably less than 10 members, most preferably 1, of nucleic acids having satisfactory specificity is obtained, the aptamer is sequenced and characterized. Pure preparations of a given aptamer are generated by any appropriate technique (e.g., PCR amplification, in vitro chemical synthesis, and the like).[0525]
• For example, Tuerk and Gold (Science (1990) 249:505-510) disclose the use of a procedure termed “systematic evolution of ligands by exponential enrichment” (SELEX). In this method, pools of nucleic acid molecules that are randomized at specific positions are subjected to selection for binding to a nucleic acid-binding protein (see, e.g., PCT International Publication No. WO 91/19813 and U.S. Pat. No. 5,270,163). The oligonucleotides so obtained are sequenced and otherwise characterization. Kinzler, K. W., et al. (Nucleic Acids Res. (1989) 17:3645-3653) used a similar technique to identify synthetic double-stranded DNA molecules that are specifically bound by DNA-binding polypeptides. Ellington, A. D., et al. (Nature (1990) 346: 818-822) disclose the production of a large number of random sequence RNA molecules and the selection and identification of those that bind specifically to specific dyes such as Cibacron blue.[0526]
• Another technique for identifying nucleic acids that bind non-nucleic target molecules is the oligonucleotide combinatorial technique disclosed by Ecker, D. J. et al. (Nuc. Acids Res. 21, 1853 (1993)) known as “synthetic unrandomization of randomized fragments” (SURF), which is based on repetitive synthesis and screening of increasingly simplified sets of oligonucleotide analogue libraries, pools and mixtures (Tuerk et al., Science 249:505, 1990). The starting library consists of oligonucleotide analogues of defined length with one position in each pool containing a known analogue and the remaining positions containing equimolar mixtures of all other analogues. With each round of synthesis and selection, the identity of at least one position of the oligomer is determined until the sequences of optimized nucleic acid ligand aptamers are discovered.[0527]
• Once a particular candidate aptamer has been identified through a SURF, SELEX or any other technique, its nucleotide sequence can be determined (as is known in the art), and its three-dimensional molecular structure can be examined by nuclear magnetic resonance (NMR). These techniques are explained in relation to the determination of the three-dimensional structure of a nucleic acid ligand that binds thrombin in Padmanabhan et al., J. Biol. Chem. 24, 17651 (1993); Wang et al., Biochemistry 32, 1899 (1993); and Macaya et al., Proc. Nat'l. Acad. Sci. USA 90, 3745 (1993). Selected aptamers may be resynthesized using one or more modified bases, sugars or backbone linkages. Aptamers consist essentially of the minimum sequence of nucleic acid needed to confer binding specificity, but may be extended on the 5′ end, the 3′ end, or both, or may be otherwise derivatized or conjugated.[0528]
• IX. Polypeptidic Binding Moieties[0529]
• A variety of binding moities can be attached to a minicell of the invention for a variety of purposes. In a preferred embodiment, the binding moiety is directed to a ligand that is displayed by a cell into which it is desired to deliver the therapeutic content of a minicell.[0530]
• IX.A. Antibodies and Antibody Derivatives[0531]
• The term “antibody” is meant to encompass an immunoglobulin molecule obtained by in vitro or in vivo generation of an immunogenic response, and includes polyclonal, monospecific and monoclonal antibodies, as well as antibody derivatives, e.g single-chain antibody fragments (scFv). An “immunogenic response” is one that results in the production of antibodies directed to one or more proteins after the appropriate cells have been contacted with such proteins, or polypeptide derivatives thereof, in a manner such that one or more portions of the protein function as epitopes. An epitope is a single antigenic determinant in a molecule. In proteins, particularly denatured proteins, an epitope is typically defined and represented by a contiguous amino acid sequence. However, in the case of nondenatured proteins, epitopes also include structures, such as active sites, that are formed by the three-dimensional folding of a protein in a manner such that amino acids from separate portions of the amino acid sequence of the protein are brought into close physical contact with each other.[0532]
• Wildtype antibodies have four polypeptide chains, two identical heavy chains and two identical light chains. Both types of polypeptide chains have constant regions, which do not vary or vary minimally among antibodies of the same class (i.e., IgA, IgM, etc.), and variable regions. Variable regions are unique to a particular antibody and comprise an “antigen binding domain” that recognizes a specific epitope. Thus, an antibody's specificity is determined by the variable regions located in the amino terminal regions of the light and heavy chains.[0533]
• As used herein, the term “antibody” encompasses derivatives of antibodies such as antibody fragments that retain the ability to specifically bind to antigens. Such antibody fragments include Fab fragments (i.e., an antibody fragment that contains the antigen-binding domain and comprises a light chain and part of a heavy chain bridged by a disulfide bond); Fab′ (an antibody fragment containing a single anti-binding domain comprising an Fab and an additional portion of the heavy chain through the hinge region); F(ab′)2 (two Fab′ molecules joined by interchain disulfide bonds in the hinge regions of the heavy chains; the Fab′ molecules may be directed toward the same or different epitopes); a bispecific Fab (an Fab molecule having two antigen binding domains, each of which may be directed to a different epitope); a single chain Fab chain comprising a variable region, a.k.a., a sFv (the variable, antigen-binding determinative region of a single light and heavy chain of an antibody linked together by a chain of about 10 to about 25 amino acids).[0534]
• The term “antibody” includes antibodies and antibody derivatives that are produced by recombinant DNA techniques and “humanized” antibodies. Humanized antibodies have been modified, by genetic manipulation and/or in vitro treatment to be more human, in terms of amino acid sequence, glycosylation pattern, etc., in order to reduce the antigenicity of the antibody or antibody fragment in an animal to which the antibody is intended to be administered (Gussow et al., Methods Enz. 203:99-121, 1991).[0535]
• A single-chain antibody (scFv) is a non-limiting example of a binding moiety that may be displayed on minicells. Single-chain antibodies are produced by recombinant DNA technology and may be incorporated into fusion proteins. The term “single chain” denotes the fact that scFv's are found in a single polypeptide. In contrast, wildtype antibodies have four polypeptide chains, two identical heavy chains and two identical light chains. Both types of polypeptide chains have constant regions, which do not vary or vary minimally among antibodies of the same class (i.e., IgA, IgM, etc.), and variable regions. An antibody's specificity is determined by the variable regions located in the amino terminal regions of the light and heavy chains. The variable regions of a light chain and associated heavy chain form an “antigen binding domain” that recognizes a specific epitope. In a single chain antibody, the amino acid sequences of the variable light and variable heavy regions of an antibody are present in one contiguous polypeptide. Methods of producing single chain antibodies are known in the art. See, for example, U.S. Pat. Nos. 4,946,778; 5,260,203; 5,455,030; 5,518,889; 5,534,621; 5,869,620; 6,025,165; 6,027,725 and 6,121,424.[0536]
• Antibody derivatives and other polypeptides that are binding moieties can be isolated from protein display libraries, in which a library of candidate binding agents is displayed on a phage or other agent that comprises a nucleic acid encoding the protein it displays. Thus, an agent that binds to the target compound can be isolated, and nucleic acid prepared therefrom, providing for the rapid isolation of binding moieties and nucleic acids that can be used to produce them. For reviews, see Benhar I. Biotechnological applications of phage and cell display. Biotechnology Adv. 2001 (19): 1-33; FitzGerald K. In vitro display technologies—new tools for drug discovery. Drug Discov Today. 2000 5(6):253-258; and Hoogenboom H R, Chames P. Natural and designer binding sites made by phage display technology. Immunol Today. August 2000;21(8):371-8.[0537]
• A variety of protein display systems are known in the art and include various phage display systems such as those described in Jung S, Arndt K, Müller K, Plückthyn A. Selectively infective phage (SIP) technology: scope and limitations. J Immunol Methods. 1999 (231):93-104; Katz B. Structural and mechanistic determinants of affinity and specificity of ligands discovered or engineered by phage display. Annu Rev Biophys Biomol Struct. 1997 (26):27-45; Forrer P, Jung S, Pluckthun A. Beyond binding: using phage display to select for structure, folding and enzymatic activity in proteins. Curr Opin Struct Biol. August 1999;9(4):514-20; Rondot S, Koch J, Breitling F, Dubel S. A helper phage to improve single-chain antibody presentation in phage display. Nat Biotechnol. January 2001; 19(1):75-8. Giebel L B, Cass R T, Milligan D L, Young D C, Arze R, Johnson C R. Screening of cyclic peptide phage libraries identifies ligands that bind streptavidin with high affinities. Biochemistry. Nov. 28, 1995;34(47):15430-5; de Kruif J, Logtenberg T. Leucine zipper dimerized bivalent and bispecific scFv antibodies from a semi-synthetic antibody phage display library. J Biol Chem. Mar. 29, 1996;271(13):7630-4; Hoogenboom H R, Hende rikx P, de Haard H. Creating and engineering human antibodies for immunotherapy. Adv Drug Deliv Rev. Apr. 6, 1998;31(1-2):5-31; Helfrich W, Haisma H J, Magdolen V, Luther T, Bom V J, Westra J, van der Hoeven R, Kroesen B J, Molema G, de Leij L. A rapid and versatile method for harnessing scFv antibody fragments with various biological effector functions. J Immunol Methods. Apr. 3, 1998;237(1-2):131-45; Hoess R H. Bacteriophage lambda as a vehicle for peptide and protein display. Curr Pharm Biotechnol March 2002;3(1):23-8; Baek H, Suk K H, Kim Y H, Cha S. An improved helper phage system for efficient isolation of specific antibody molecules in phage display. Nucleic Acids Res.[0538]Mar 1, 2002;30(5):el8; and Rondot S, Koch J, Breitling F, Dubel S. A helper phage to improve single-chain antibody presentation in phage display. Nat Biotechnol. January 2001;19(1):75-8.
• Other display systems include without limitation “Yeast Display” (Curr Opin Biotechnol October 1999;10(5):422-7. Applications of yeast in biotechnology: protein production and genetic analysis. Cereghino G P, Cregg J M.); “Baculovirus Display” (Kost T A, Condreay J P. Recombinant baculoviruses as expression vectors for insect and mammalian cells. Curr Opin Biotechnol. October 1999; 10(5):428-33; and Liang M, Dubel S, Li D, Queitsch I, Li W, Bautz E K. Baculovirus expression cassette vectors for rapid production of complete human IgG from phage display selected antibody fragments. J Immunol Methods. Jan. 1, 2001;247(1-2):119-30); “Ribosome Display” (Hanes J, Schaffitzel C, Knappik A, Pluckthun A. Picomolar affinity antibodies from a fully synthetic naive library selected and evolved by ribosome display. Nat Biotechnol. 2000 Dec; 18(12):1287-92; Hanes J, Jermutus L, Pluckthun A. Selecting and evolving functional proteins in vitro by ribosome display. Methods Enzymol. 2000;328:404-30; Schaffitzel C, Hanes J, Jermutus L, Pluckthun A. Ribosome display: an in vitro method for selection and evolution of antibodies from libraries. J Immunol Methods. Dec. 10, 1999;231(1-2):119-35; Hanes J, Jermutus L, Weber-Bornhauser S, Bosshard H R, Pluckthun A. Ribosome display efficiently selects and evolves high-affinity antibodies in vitro from immune libraries. Proc Natl Acad Sci U S A. Nov. 24, 1998;95(24): 14130-5; Hanes J, Pluckthun A. In vitro selection and evolution of functional proteins by using ribosome display. Proc Natl Acad Sci U S A. May 13, 1997;94(10):4937-42; Coia G, Pontes-Braz L, Nuttall S D, Hudson P J, Irving R A. Panning and selection of proteins using ribosome display. J Immunol Methods. Aug. 1, 2001;254(1-2):191-7.; Irving R A, Coia G, Roberts A, Nuttall S D, Hudson P J. Ribosome display and affinity maturation: from antibodies to single V-domains and steps towards cancer therapeutics. J Immunol Methods. Feb. 1, 2001;248(1-2):31-45); and “Bacterial Display” (Hoischen C, Fritsche C, Gumpert J, Westermann M, Gura K, Fahnert B. Novel bacterial membrane surface display system using cell wall-less L-forms of Proteus mirabilis and[0539]Escherichia coli.Appl Environ Microbiol. February 2002;68(2):525-31; Etz H, Minh D B, Schellack C, Nagy E, Meinke A. Bacterial phage receptors, versatile tools for display of polypeptides on the cell surface. J Bacteriol. December 2001;183(23):6924-35; Patel D, Vitovski S, Senior H J, Edge M D, Hockney R C, Dempsey M J, Sayers J R. Continuous affinity-based selection: rapid screening and simultaneous amplification of bacterial surface-display libraries. Biochem J. Aug. 1, 2001;357(Pt 3):779-85; Lang H. Outer membrane proteins as surface display systems. Int J Med Microbiol. December 2000;290(7):579-85; Earhart C F. Use of an Lpp-OmpA fusion vehicle for bacterial surface display. Methods Enzymol. 2000;326:506-16; Benhar I, Azriel R, Nahary L, Shaky S, Berdichevsky Y, Tamarkin A, Wels W. Highly efficient selection of phage antibodies mediated by display of antigen as Lpp-OmpA′ fusions on live bacteria. J Mol Biol. Aug. 25, 2000;301(4):893-904; Xu Z, Lee S Y. Display of polyhistidine peptides on theEscherichia colicell surface by using outer membrane protein C as an anchoring motif. Appl Environ Microbiol. November 1999;65(11):5142-7; Daugherty P S, Olsen M J, Iverson B L, Georgiou G. Development of an optimized expression system for the screening of antibody libraries displayed on theEscherichia colisurface. Protein Eng. July 1999; 12(7):613-21; Chang H J, Sheu S Y, Lo S J. Expression of foreign antigens on the surface ofEscherichia coliby fusion to the outer membrane protein traT. J Biomed Sci. January 1999;6(1):64-70; Maurer J, Jose J, Meyer T F. Autodisplay: one-component system for efficient surface display and release of soluble recombinant proteins fromEscherichia coli.J Bacteriol. February 1997; 179(3):794-804.
• Antibodies, particularly single-chain antibodies, directed to surface antigens specific for a particular cell type may also be used as cell- or tissue-specific targeting elements. Single-chain antibody amino acid sequences have been incorporated into a variety of fusion proteins, including those with transmembrane domains and/or membrane-anchoring domains. See, for example, Kuroki et al., “Specific Targeting Strategies of Cancer Gene Therapy Using a Single-Chain Variable Fragment (scFv) with a High Affinity for CEA,” Anticancer Res., pp. 4067-71, 2000; U.S. Pat. No. 6,146,885, to Dornburg, entitled “Cell-Type Specific Gene Transfer Using Retroviral Vectors Containing Antibody-Envelope Fusion Proteins”; Jiang et al., “In Vivo Cell Type-Specific Gene Delivery With Retroviral Vectors That Display Single Chain Antibodies,” Gene Ther. 1999, 6:1982-7; Engelstadter et al., “Targeting Human T Cells By Retroviral Vectors Displaying Antibody Domains Selected From A Phage Display Library,” Hum. Gene Ther. 2000, 11:293-303; Jiang et al., “Cell-Type-Specific Gene Transfer Into Human Cells With Retroviral Vectors That Display Single-Chain Antibodies,” J. Virol 1998,72:10148-56; Chu et al., “Toward Highly Efficient Cell-Type-Specific Gene Transfer With Retroviral Vectors Displaying Single-Chain Antibodies,” J. Virol 1997, 71:720-5; Chu et al., “Retroviral Vector Particles Displaying The Antigen-Binding Site Of An Antibody Enable Cell-Type-Specific Gene Transfer,” J. Virol 1995, 69:2659-63; Chu et al., “Cell Targeting With Retroviral Vector Particles Containing Antibody-Envelope Fusion Proteins,” Gene Ther. 1994, 1:292-9; Esshar et al., “Specific activation and targeting of cytotoxic lymphocytes through chimeric single chains consisting of antibody-binding domains and the or subunits of the immunoglobulin and T-cell receptors,” Proc. Natl. Acad. Sci. USA, 1993, Vol. 90:720-724; Einfeld et al., “Construction of a Pseudoreceptor That Mediates Transduction by Adenoviruses Expressing a Ligand in Fiber or Penton Base,” J. Virol. 1999, 73:9130-9136; Marin et al., “Targeted Infection of Human Cells via Major Histocompatibility Complex Class I Molecules by Moloney Murine Leukemia Virus-Derived Viruses Displaying Single-Chain Antibody Fragment-Envelope Fusion Proteins,” J. Virol., 1996, 70:2957-2962; Somia et al., “Generation of targeted retroviral vectors by using single-chain variable fragment: An approach to in vivo gene delivery,” Proc. Natl. Acad. Sci. USA, 1995, 92:7570-7574; Liu et al., “Treatment of B-Cell Lymphoma With Chimeric IgG and Single-Chain Fv Antibody-Interleukin-2 Fusion Proteins,” Blood, 1998, 92:2103-2112; Martin et al., “Retrovirus Targeting by Tropism Restriction to Melanoma Cells,” J. Virol., 1999, 73:6923-6929; Ramjiawan et al., “Noninvasive Localization of Tumors by Immunofluorescence Imaging Using a Single Chain Fv Fragment of a Human Monoclonal Antibody with Broad Cancer Specificity,” Amer. Cancer Society, 2000, 89:1134-1144; Snitkovsky et al., “A TVA-Single-Chain Antibody Fusion Protein Mediates Specific Targeting of a Subgroup A Avian Leukosis Virus Vector to Cells Expressing a Tumor-Specific Form of Epidermal Growth Factor Receptor,” J. Virol., 2000, 74:9540-9545; Chu et al., “Toward Highly Efficient Cell-Type-Specific Gene Transfer with Retroviral Vectors Displaying Single-Chain Antibodies,” J. Virol., 1997, 71:720-725; Kulkarni et al.,Programmed cell death signaling via cell-surface expression of a single-chain antibody transgene,Transplantation Mar, 27, 2000;69(6):1209-17.[0540]
• IX.B. Non-Catalytic Derivatives of Active Sites of Enzymes[0541]
• Enzymes bind their substrates, at least transiently, in regions known as “active sites.” It is known in the art that non-catalytic derivatives of enzymes, which bind but do not chemically alter their substrates may be prepared. Non-catalytic enzymes, particularly the mutant active sites thereof, are used to bind substrate molecules.[0542]
• As a non-limiting example, enzymes from which biologically inactive (non-catalytic) sphingolipid-binding derivatives are obtained. Such derivatives of these enzymes bind their substrate sphingolipid. Sphingosine-1-phosphate (S1P) is bound by non-catalytic derivatives of enzymes having S1P as a substrate, e.g., S1P lyase and S1P phosphatase. Sphingosine (SPH) is bound by non-catalytic derivatives of enzymes having SPH as a substrate, e.g., SPH kinase and ceramide synthase. Ceramide (CER) is bound by non-catalytic derivatives of enzymes having CER as a substrate, such as, by way of non-limiting example, ceramidase, sphingomyelin synthase, ceramide kinase, and glucosylceramide synthase. Sphingomyelin is bound by non-catalytic derivatives of sphingomyelinase, an enzyme having sphingomyelin as a substrate.[0543]
• IX.C. Nucleic Acid Binding Domains[0544]
• Nucleic acid binding polypeptide domains may bind nucleic acids in a sequence-dependent or sequence-independent fashion and/or in a manner that is specific for various nucleic acids having different chemical structures (e.g., single- or double-stranded DNA or RNA, RNA:DNA hybrid molecules, etc.). Non-limiting examples of membrane-based transcription factors and DNA-binding protein include Smad proteins (Miyazono et al., TGF-beta signaling by Smad proteins (Review), Adv Inununol 75:115-57, 2000); SREBPs (sterol regulatory element binding proteins) (Ye et al., Asparagine-proline sequence within membrane-spanning segment of SREBP triggers intramembrane cleavage by site-2 protease, Proc Natl Acad Sci USA 97:5123-8, 2000; Shimomura et al., Cholesterol feeding reduces nuclear forms of sterol regulatory element binding proteins in hamster liver, Proc Natl Acad Sci USA 94:12354-9, 1997; Brown and Goldstein, The SREBP pathway: regulation of cholesterol metabolism by proteolysis of a membrane-bound transcription factor (Review), Cell 89:331-40, 1997; Scheek et al., Sphingomyelin depletion in cultured cells blocks proteolysis of sterol regulatory element binding proteins at site 1, Proc Natl Acad Sci USA 94:11179-83, 1997); mitochondrial DNA-binding membrane proteins, e.g., Abf2p and YhmZp (Cho et al., A novel DNA-binding protein bound to the mitochondrial inner membrane restores the null mutation of mitochondrial histone Abf2p in Saccharomyces cerevisiae, Mol Cell Biol 18:5712-23, 1998); and bacterial DNA-binding membrane proteins (Smith et al., Transformation in[0545]Bacillus subtilis:purification and partial characterization of a membrane-bound DNA-binding protein., J Bacteriol 156:101-8, 1983).
• IX.D. Attaching Binding Moities, or Other Compounds, to Minicells[0546]
• Binding compounds or moieties can be chemically attached (conjugated) to minicells via membrane proteins that are displayed on the minicells. The compound to be conjugated to minicells (the “attachable compound”) may of any chemical composition, i.e., a small molecule, a nucleic acid, a radioisotope, a lipid or a polypeptide. One type of attachable compound that can be covalently attached to minicells is a binding moitiety, e.g., an antibody or antibody derivative. Another non-limiting example of attachable compounds is polyethylene glycol (“PEG”), which lowers the uptake in vivo of minicells by the reticuloendothelical system (RES). Another non-limiting example of creating stealth minicells to avoid the RES is to express proteins or other molecules on the surfaces of minicells whose lipid compositions have been modified, such as anionic lipid-rich minicells.[0547]
• By way of non-limiting example, it is possible to prepare minicells that express transmembrane proteins with cysteine moieties on extracellular domains. Linkage of the membrane protein may be achieved through surface cysteinyl groups by, e.g., reduction with cysteinyl residues on other compounds to form disulfide bridges (S═S). If appropriate cysteinyl residues are not present on the membrane protein they may be introduced by genetic manipulation. The substitution of cysteine for another amino acid may be achieved by methods well-known to those skilled in the art, for example, by using methods described in Maniatis, Sambrook, and Fritsch (Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, 1989). As a non-limiting example, bioactive lysosphingolipids (e.g., sphingosine, sphingosine-1-phosphate, sphingosylphosphoryl choline) are covalently linked to proteins expressed on the surfaces of minicells such that these bioactive lipids are on the surface of the minicells and accessible for therapeutic or diagnostic uses in vivo or in vitro.[0548]
• When the attachable moiety and the membrane protein both have a reduced sulfhydryl group, a homobifunctional cross-linker that contains maleimide, pyridyl disulfide, or beta-alpha-haloacetyl groups may be used for cross-linking. Examples of such cross-linking reagents include, but are not limited to, bismaleimidohexane (BMH) or 1,4-Di-[3′-(2′-pyridyldithio)propionamido]butane (DPDPB). Alternatively, a heterobifunctional cross-linker that contains a combination of maleimide, pyridyl disulfide, or beta-alpha-haloacetyl groups can be used for cross-linking.[0549]
• As another non-limiting example, attachable moieties may be chemically conjugated using primary amines. In these instances, a homobifunctional cross-linker that contains succiminide ester, imidoester, acylazide, or isocyanate groups may be used for cross-linking. Examples of such cross-linking reagents include, but are not limited to: Bis[2-(succinimidooxycarbonyloxy)ethyl]sulfone (BSOCOES); Bis[2-(sulfosuccinimidooxycarbonyloxy)ethyl]sulfone (sulfo-BSCOCOES); Disuccinimidyl suberate (DSS); Bis-(Sulfosuccinimidyl) Suberate (BS3); Disuccinimlidyl glutarate (DSG); Dithiobis(succinimidylpropionate) (DSP); Dithiobois(sulfosuccinimidylpropionate) (DTSSP); Disulfosuccinimidyl tartrate (sulfo-DST); Dithio-bis-maleimidoethane (DTME); Disuccinimidyl tartrate (DST); Ethylene glycolbis(sulfosuccinimidylsuccinate) (sulfo-EGS); Dimethyl malonimidate.2 HCl (DMM); Ethylene glycolbis(succinimidylsuccinate) (EGS); Dimethyl succinimidate.2 HCl (DMSC); Dimethyl adipimidate.2 HCl (DMA); Dimethyl pimelimidate.2 HCl (DMP); and Dimethyl suberimidate.2.HCl (DMS), and Dimethyl 3,3′-dithiobispropionimidate.2 HCl (DTBP). Heterobifunctional cross-linkers that contains a combination of imidoester or succinimide ester groups may also be used for cross-linking.[0550]
• As another non-limiting example, attachable moieties may be chemically conjugated using sulfhydryl and primary amine groups. In these instances, heterobifunctional cross-linking reagents are preferable used. Examples of such cross-linking reagents include, but are not limited to: N-succinimidyl 3-(2- pyridyldithio)propionate (DPDP); N-succinimidyl 6-[3′-(2-pyridyldithio)propionamido]hexanoate (sulfo-LC-SPDP); m-maleimidobenzoyl-N-hydoxysuccinimide ester (MBS); m-maleimidobenzoyl-N-hydoxysulfosuccinimide ester (sulfo-MBS); succinimidyl 4-[P-maleimidophenyl]butyrate (SMPB); sulfosuccinimidyl 4-[p-maleimidophenyl]butyrate (sulfo-SMPB); N-[γ-Maleimidobutyryloxy]succinimide ester (GMBS), N-[γ-maleimidobutyryloxy]sulfosuccinimide ester (sulfo-GMBS); N-[ε-maleimidocaproyloxy]succinimide ester (EMCS); N-[ε-maleimidocaproyloxy]sulfosuccinimide ester (sulfo-EMCS); N-succinimidyl(4-iodoacetyl)aminobenzoate (SIAB); sulfosuccinimidyl(4-iodacetyl)aminobenzoate (sulfo-SIAB); succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC); sulfosuccinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate (sulfo-SMCC); succiminidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxy-(6-amido-caproate) (LC-SMCC); 4-succinimidyloxycarbonyl-methyl-(2-pyridyldithio) toluene (SMPT); and sulfo-LC-SMPT.[0551]
• As an exemplary protocol, a minicell suspension is made 5 mM EDTA/PBS, and a reducing solution of 2-mercaptoethylamine in 5 mM EDTA/PBS is added to the minicells. The mixture is incubated for 90 minutes at 37° C. The minicells are washed with EDTA/PBS to remove excess 2-mercaptoethylamine. The attachable moiety is dissolved in PBS, pH 7.2. A maleimide crosslinker is added to the solution, which is then incubated for 1 hour at room temperature. Excess maleimide is removed by column chromatography.[0552]
• The minicells with reduced sulfhydryl groups are mixed with the derivatized compounds having an attachable moiety. The mixture is allowed to incubate at 4° C. for 2 hours or overnight to allow maximum coupling. The conjugated minicells are washed to remove unreacted (unattached) compounds having the attachable moiety. Similar protocols are used for expressed membrane proteins with other reactive groups (e.g., carboxyl, amine) that can be conjugated to an attachable moiety.[0553]
• IX.E. Non-Genetic Methods for Directing Compounds to Membranes[0554]
• Included within the scope of the invention are compounds that can be inserted into the membrane of segregated minicells. Such compounds include attachable moieties that are chemically conjugated to the surface of a minicell, and compounds that associate with and/or insert into a membrane “spontaneously,” i.e., by virtue of their chemical nature. By way of non-limiting example, proteins that “spontaneously” insert into membranes include but are not limited to Thykaloid membrane proteins (Woolhead et al., J. Biol. Chem. 276:14607-14613, 2001), the mitochondrial adenine nucleotide translocator (Jacotot et al., J. Exp. Med. 193:509-519, 2001), and polypeptides obtained using the methods of Hunt et al. (Spontaneous, pH-dependent membrane insertion of a transbilayer alpha-helix, Biochem 36:15177-15192, 1997). Lipids, gangliosides, sphingomyelins, plasmalogens glycosyl diacylglycerols, and sterols can also be incorporated into the membranes of segregated minicells.[0555]
• X. Membrane Proteins[0556]
• In certain aspects of the invention, membrane proteins from non-eubacterial organisms are expressed and displayed by minicells. The cellular membrane (a.k.a. the “plasma membrane”) is a lipid bilayer that forms the boundary between the interior of a cell and its external environment. The term “membrane proteins” refers to proteins that are found in membranes including without limitation cellular and organellar membranes.[0557]
• X.A. Types of Membrane Proteins[0558]
• X.A.1. In General[0559]
• Membrane proteins consist, in general, of two types, peripheral membrane proteins and integral membrane proteins.[0560]
• Integral membrane proteins can span both layers (or “leaflets”) of a lipid bilayer. Thus, such proteins may have extracellular, transmembrane, and intracellular domains. Extracellular domains are exposed to the external environment of the cell, whereas intracellular domains face the cytosol of the cell. The portion of an integral membrane protein that traverses the membrane is the “transmembrane domain.” Transmembrane domains traverse the cell membrane often by one or more regions comprising 15 to 25 hydrophobic amino acids which are predicted to adopt an alpha-helical conformation.[0561]
• Intergral membrane proteins are classified as bitopic or polytopic (Singer, (1990) Annu. Rev. Cell Biol. 6:247-96). Bitopic proteins span the membrane once while polytopic proteins contain multiple membrane-spanning segments.[0562]
• A peripheral membrane protein is a membrane protein that is bound to the surface of the membrane and is not integrated into the hydrophobic layer of a membrane region. Peripheral membrane proteins do not span the membrane but instead are bound to the surface of a membrane, one layer of the lipid bilayer that forms a membrane, or the extracellular domain of an integral membrane protein.[0563]
• X.A.2. In General[0564]
• The invention can be applied to any membrane protein, including but not limited to the following exemplary receptors and membrane proteins. The proteins include but are not limited to are receptors (e.g., GPCRs, sphingolipid receptors, neurotransmitter receptors, sensory receptors, growth factor receptors, hormone receptors, chemokine receptors, cytokine receptors, immunological receptors, and compliment receptors, FC receptors), channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases.), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN), chemotactic/adhesion proteins (e.g., ICAM11, selectins, CD34, VCAM-1, LFA-1,VLA-1), and phospholipases such as PI-specific PLC and other phospholipiases.[0565]
• X.A.3. Receptors[0566]
• Within the scope of the invention are any receptor, including without limitation:[0567]
• The nuclear receptors, e.g the nuclear export receptor;[0568]
• The peripheral (mitochondrial) benzodiazephine receptor (Gavish et al., “Enigma of the Peripheral Benzodiazephine Receptor,” Pharmacological Reviews, Vol. 51, No. 4);[0569]
• Adrenergic and muscarinic receptors (Brodde et al., “Adrenergic and Muscarinic Receptors in the Human Heart”, Pharmacological Review, Vol. 51, No. 4);[0570]
• Gamma-aminobutyric acid[0571]_Areceptors (Barnard et al., “International Union of Pharmacology. IV. Subtypes of γ-Aminobutyric Acid_AReceptors: Classification on the Basis of Submit Structure and Receptor Function,” Pharmacological Reviews, Vol. 50, No. 2);
• Kinin B[0572]₁receptors (Marceau et al., “The B₁Receptors for Kinins,” Pharmacological Reviews, Vol. 50, No. 3);
• Chemokine receptors (Murphy et al., “International Union of Pharmacology. XXII. Nomenclature for Chemokine Receptors” Pharmacological Reviewa, Vol. 52, No. 1);[0573]
• Glycine and NMDA Receptors (Danysz et al., “Glycine and N-Methyl-D-Aspartate Receptors: Physiological Significance and Possible Therapeutic Applications,” Pharmacological Reviews, Vol. 50, No. 4);[0574]
• Glutamate receptor ion channels (Dingledine et al., “The Glutamate Receptor Ion Channels”, Pharmacological Reviews, Vol. 51, No. 1);[0575]
• Purine and pyrimidine receptors including purinergic (e.g., P2) receptors (Ralevic et al., “Receptors for Purines and Pyrimidines”, Pharmacological Reviews, Vol. 50, No. 3); CNS receptors and membrane transporters (E. Sylvester Vizi, “Role of High-Affinity Receptors and Membrane Transporters in Nonsynaptic Communication and Drug Action in the Central Nervous System,” Pharmacological Reviews, Vol. 52, No. 1);[0576]
• Opoid receptors, including but not limited to the 8-opioid receptor (Quock et al., “The δ-Opioid Receptor: Molecular Pharmacology, Signal Transduction and the Determination of Drug Efficacy”, Pharmacological Review, Col. 51, No. 3);[0577]
• Angiotensin II receptors (Gasparo et al., “International Union of Pharmacology. XXIII. The Angiotensin II Receptors” Pharmalogical Review, Vol. 52, No. 3);[0578]
• Cholecystokinin receptors (Noble et al., “International Union of Pharmacology. XXI. Structure, Distribution, and Functions of Cholecystokinin Receptors”, Pharmacological Reviews, Vol. 51, No. 4)[0579]
• Hormone receptors, including but not limited to, the estrogen receptor; the glucocorticoid receptor; and the insulin receptor;[0580]
• Receptors found predominantly in the central nervous system, including but not limited to, neuronal nicotinic acetylcholine receptors; the dopamine D2/D3 receptor; GABA receptors; central cannabinoid receptor CB1; opoid receptors, e.g., the kappa opioid receptor, and the methadone-specific opioid. receptor; nicotinic acetylcholine receptors; serotonin receptors, e.g., the serotonin 5-HT3 receptor, the serotonin 5-HT4 receptor, and the serotonin-2 receptor; and dopamine receptors, e.g., the dopamine D2/D3 receptor; and the neurotensin receptor;[0581]
• Receptors for growth factors, including but not limited to, the erythropoietin receptor; the FGF receptor; the EGF receptor; the VEGF receptor; VEGF receptor-2 protein; VEGF-receptor protein (KDR); fibroblast growth factor receptor; the p75 nerve growth factor receptor; epidermal growth factor receptor; IGF-1 receptor; platelet factor-4 receptor; alpha platelet-derived growth factor receptor; hepatocyte growth factor receptor; and human fibroblast growth factor receptor;[0582]
• Receptors for sphingolipids and lysophospholipids such as the Edg family of GPCRs;[0583]
• Receptors for interleukins, e.g., receptors for interleukin-1 (IL-1), IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-11, IL-12, IL-13, et seq.; and[0584]
• Various receptors, including by way of non-limiting example, receptors described in U.S. Pat. No. 6,210,967 (DNA encoding a mammalian LPA receptor and uses thereof); U.S. Pat. No. 6,210,921 (CAR: a novel coxsackievirus and adenovirus receptor; U.S. Pat. No. 6,211,343 (Lactoferrin receptor protein; U.S. Pat. No. 6,218,509 (LH/CG receptor, DNA and use thereof; U.S. Pat. No. 6,214,972 (DNA encoding prostaglandin receptor DP); U.S. Pat. No. 6,221,613 (DNA encoding a human melanin concentrating hormone receptor (MCH1) and uses thereof); U.S. Pat. No. 6,221,660 (DNA encoding SNORF25 receptor); U.S. Pat. No. 6,225,080 (Mu-subtype opioid receptor); U.S. Pat. No. 6,222,015 (Estrogen receptor); U.S. Pat. No. 6,228,610 (Human metabotropic glutamate receptor subtypes (hmR4, hmR6, hmR7) and related DNA compounds); U.S. Pat. No. 6,235,496 (Nucleic acid encoding mammalian mu opioid receptor); U.S. Pat. No. 6,258,556 (cDNA and genomic clones encoding human .mu. opiate receptor and the purified gene product); U.S. Pat. No. 6,245,531 (Polynucleotide encoding insect ecdysone receptor); U.S. Pat. No. 6,225,531 Glucan elicitor receptor, DNA molecule coding therefor, fungus-resistant plants transformed with the DNA molecule and method for creating the plants); U.S. Pat. No. 6,245,893 (Receptor that binds anti-convulsant compounds); U.S. Pat. No. 6,248,712 (Urokinase-type plasminogen activator receptor; U.S. Pat. No. 6,248,554 (DNA sequence coding for a BMP receptor); U.S. Pat. No. 6,248,520 (Nucleic acid molecules encoding nuclear hormone receptor coactivators and uses thereof); U.S. Pat. No. 6,242,251 (Rhesus neuropeptide Y5 receptor); U.S. Pat. No. 6,252,056 (Human lysophosphatidic acid receptor and use thereof); U.S. Pat. No. 6,255,472 (Isolated nucleic acid molecule encoding a human skeletal muscle-specific receptor); U.S. Pat. No. 6,291,207 (Herpes virus entry receptor protein); U.S. Pat. No. 6,291,206 (BMP receptor proteins); U.S. Pat. No. 6,291,195 (DNA encoding a human melanin concentrating hormone receptor (MCH1) and uses thereof); U.S. Pat. No. 6,344,200 (Lactoferrin receptor protein); U.S. Pat. No. 6,335,180 (Nucleic acid sequences encoding capsaicin receptor and uses thereof); U.S. Pat. No. 6,265,184 (Polynucleotides encoding chemokine receptor 88C); U.S. Pat. No. 6,207,799 (Neuropeptide Y receptor Y5 and nucleic acid sequences); U.S. Pat. No. 6,290,970 (Transferrin receptor protein of Moraxella); U.S. Pat. No. 6,326,350 (Transferrin receptor subunit proteins of[0585]Neisseria meningitidis); U.S. Pat. No. 6,313,279 (Human glutamate receptor and related DNA compounds); U.S. Pat. No. 6,313,276 (Human endothelin receptor); U.S. Pat. No. 6,307,030 (Androgen receptor proteins, recombinant DNA molecules coding for such, and use of such compositions); U.S. Pat. No. 6,306,622 (cDNA encoding a BMP type II receptor); U.S. Pat. No. 6,300,087 (DNA encoding a human serotonin receptor (5-HT4B) and uses thereof); U.S. Pat. No. 6,297,026 (Nucleic acids encoding the C140 receptor); U.S. Pat. No. 6,277,976 (Or-1, an orphan receptor belonging to the nuclear receptor family); U.S. Pat. No. 6,274,708 (Mouse interleukin-11 receptor); U.S. Pat. No. 6,271,347 (Eosinophil eotaxin receptor); U.S. Pat. No. 6,262,016 (Transferrin receptor genes); U.S. Pat. No. 6,261,838 (Rat melanocortin receptor MC3-R); U.S. Pat. No. 6,258,943 (Human neurokinin-3 receptor); U.S. Pat. No. 6,284,870 (Gamma retinoic acid receptor); U.S. Pat. No. 6,258,944 (OB receptor isoforms and nucleic acids encoding them); U.S. Pat. No. 6,261,801 (Nucleic acids encoding tumor necrosis factor receptor 5); U.S. Pat. No. 6,261,800 (Luteinizing hormone/choriogonadotropin (LH/CG) receptor); U.S. Pat. No. 6,265,563 (Opioid receptor genes); U.S. Pat. No. 6,268,477 (Chemokine receptor 88-C); U.S. Pat. No. 6,316,611 (Human N-methyl-D-aspartate receptor subunits, nucleic acids encoding same and uses therefor); U.S. Pat. No. 6,316,604 (Human C3b/C4b receptor (CR1)); U.S. Pat. No. 6,287,855 (Nucleic acid encoding rat galanin receptor (GALR2)); U.S. Pat. No. 6,268,221 (Melanocyte stimulating hormone receptor and uses); and U.S. Pat. No. 6,268,214 (Vectors encoding a modified low affinity nerve growth factor receptor).
• X.A.3. Other Membrane Proteins[0586]
• Other membrane proteins are within the scope of the invention and include but are not limited to channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases.), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN),[0587]
• X.A.3.a. Cellular Adhesion Molecules[0588]
• Cellular adhesion molecules, including but not limited to human rhinovirus receptor (ICAM-1), ICAM-2, ICAM-3, and PECAM-1, and chemotactic/adhesion proteins (e.g., ,selectins, CD34, VCAM-1, LFA-1,VLA-1) are within the scope of the invention. See also Alpin et al., “Signal Transduction and Signal Modulation by Cell Adhesion Receptors: The Role of Integrins, Cadherins, Immunoglobulin-Cell Adhesion Molecules, and Selectins”, Pharmacological Reviews, Vol. 50, No. 2.[0589]
• X.A.3.b. Cytochrome P450 Enzymes[0590]
• The family of enzymes known as “cytochrome P450” enzymes (since they absorb light in the 450 nanometer range), or as “cytochrome oxidase” enzymes (since they oxidize a wide range of compounds that do not naturally occur in circulating blood), are included within the scope of the invention. P450 enzymes encompasses a variety of enzymes, many of which are involved in xenobiotic metabolism, including by way of non-limiting example the metabolism of drugs, prodrugs and toxins. Directories and databases of P450s, and information regarding their substrates, are available on-line (Fabian et al., The Directory of P450-containing Systems in 1996, Nucleic Acids Research 25:274-277, 1997). In humans, at least about 200 different P450s are present (for a review, see Hasler et al., Human cytochromes P450, Molecular Aspects of Medicine 20:1-137, 1999). There are multiple forms of these P450s and each of the individual forms exhibit degrees of specificity towards individual compounds or sets of compounds. In some cases, a substrate, whether it is a drug or a carcinogen, is metabolized by more than one cytochrome P450.[0591]
• Members of the cytochrome P450 family are present in varying levels and their expression and activities are controlled by variables such as chemical environment, sex, developmental stage, nutrition and age. The cytochrome P450s are found at high concentrations in liver cells, and at lower concentrations in other organs and tissues such as the lungs (e.g., Fonne-Pfister et al., Xenobiotic and endobiotic inhibitors of cytochrome P-450dbl function, the target of the debrisoquine/sparteine type polymorphism, Biochem. Pharmacol. 37:3829-35, 1988). By oxidizing lipophilic compounds, which makes them more water-soluble, cytochrome oxidase enzymes help the body eliminate (via urine, or in aerosols exhaled out of the lungs) compounds that might otherwise act as toxins or accumulate to undesired levels.[0592]
• In humans, several cytochrome P450s have been identified as being involved in xenobiotic metabolism. These include CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP3A4, and CYP3A5 (Crespi et al., The use of heterologous expressed drug metabolizing enzymes-state of the art and prospects for the future, Pharm Ther 84:121-131, 1999).[0593]
• X.A.3.c. Miscellaneous Membrane Proteins[0594]
• In addition to the preceding non-limiting examples, the invention can be applied to the membrane proteins described in U.S. Pat. No. 6,335,018 (High molecular weight major outer membrane protein of moraxella); U.S. Pat. No. 6,264,954 (Haemophilus outer membrane protein); U.S. Pat. No. 6,197,543 (Human vesicle membrane protein-like proteins); U.S. Pat. No. 6,121,427 (Major outer membrane protein CD of branhamella); U.S. Pat. Nos. 6,083,743 and 6,013,514 (Haemophilus outer membrane protein); U.S. Pat. No. 6,004,562 (Outer membrane protein B1 of[0595]Moraxella catarrhalis); U.S. Pat. No. 5,863,764 (DNA encoding a human membrane protein); U.S. Pat. No. 5,861,283 (DNA encoding a limbic system-associated membrane protein); U.S. Pat. No. 5,824,321 (Cloned leptospira outer membrane protein); U.S. Pat. No. 5,821,085 (Nucleotide sequences of a T. pallidum rare outer membrane protein); U.S. Pat. No. 5,821,055 (Chlamydia major outer membrane protein); U.S. Pat. No. 5,808,024 (Nucleic acids encoding high molecular weight major outer membrane protein of moraxella); U.S. Pat. No. 5,770,714 (Chlamydia major outer membrane protein); 5,763,589 (Human membrane protein); U.S. Pat. No. 5,753,459 (Nucleotide sequences of T. pallidum rare outer membrane protein); U.S. Pat. No. 5,607,920 (Concanavalin a binding proteins and a 76 kD chondrocyte membrane protein (CMP) from chondrocytes and methods for obtaining same); and U.S. Pat. No. 5,503,992 (DNA encoding the 15 kD outer membrane protein ofHaemophilus influenzae).
• X.B. Membrane Anchoring Domains[0596]
• A membrane-anchoring domain can be incorporated into a fusion protein of the invention. Non-limiting examples of membrane anchoring domains include those derived from Prostaglandin H2 synthases (PGHS-1 and -2) (Nina et al., Anchoring of a monotopic membrane protein: the binding of prostaglandin H2 synthase-1 to the surface of a phospholipid bilayer, Eur. Biophys. J. 29:439-54, 2000; Otto and Smith, Photolabeling of prostaglandin endoperoxide H synthase-1 with 3-trifluoro-3-(m-[125I]iodophenyl)diazirine as a probe of membrane association and the cyclooxygenase active site, J Biol Chem 271:9906-10, 1996; and Otto and Smith, The orientation of prostaglandin endoperoxide synthases-1 and -2 in the endoplasmic reticulum, J Biol Chem 269:19868-75, 1994; those derived from carboxypeptidase E (EC 3.4.17.10) (Fricker et al., Identification of the pH-dependent membrane anchor of carboxypeptidase E (EC 3.4.17.10), J. Biol. Chem., 265, 2476-2482, 1990); and peptide convertase 3 (PC3) (Smeekens et al., Identification of a cDNA encoding a second putative prohormone convertase related to PC2 in AtT20 cells and islets of Langerhans, Proc Natl Acad Sci USA 88, 340-344, 1990).[0597]
• X.C. Transmembrane Domains[0598]
• A variety of types and examples of transmembrane domain are known. Proteins with up to 12 transmembrane domains are known (Fujiwara et al., Identification of thyroid hormone transporters in humans: different molecules are involved in a tissue-specific manner, Endocrinology 2001 142:2005-12; Sharina et al., Mutational analysis of the functional role of conserved arginine and lysine residues in transmembrane domains of the murine reduced folate carrier, Mol Pharmacol 2001 59:1022-8). However, the invention is not limited to any particular number of transmembrane domains.[0599]
• Monotropic (“single pass”) domains, which traverse a membrane once, include by way of non-limiting example, those found in receptors for epidermal growth factor (EGF), receptors for tumor necrosis factor (TNF) and the like. Polytropic (“multipass”) proteins traverse a membrane two or more times. Non-limiting examples of polytropic proteins are as follows.[0600]
• Biotropic (“2 passes”) membrane proteins include, but are not limited to: EnvZ of[0601]E. coli;the peroxisomal membrane protein Pex11-1p (Anton et al., ARF- and coatomer-mediated peroxisomal vesiculation, Cell Biochem Biophys 2000;32 Spring:27-36); pleitropic drug ABC transporters ofS. cervisiae(Rogers et al., The pleitropic drug ABC transporters fromSaccharomyces cerevisiae,J Mol Microbiol Biotechnol 2001 3:207-14); and human and rate urate transporters hUAT and rUAT (Lipkowitz et al., Functional reconstitution, membrane targeting, genomic structure, and chromosomal localization of a human urate transporter, J Clin Invest 2001 107:1103-15).
• Tritropic (“3 pass”) membrane proteins include, but are not limited to: the ethylene receptor ETR1 of Arabidopsis; the Cauliflower Card Expression protein CC1 (Palmer et al., A[0602]Brassica oleraceaGene Expressed in a Variety-Specific Manner May Encode a Novel Plant Transmembrane Receptor, Plant Cell Physiol 2001 42:404-413); and a splice variant of the mitochondrial membrane protein hMRS3/4 (Li et al., Characterization of a novel human putative mitochondrial transporter homologous to the yeast mitochondrial RNA splicing proteins 3 and 4, FEBS Lett 2001 494:79-84).
• Tetraspanins or tetraspans are non-limiting examples of membrane proteins with four transmembrane domains. (Levy et al., J. Biol. Chem, 226:14597-14602, 1991; Tomlinson et al., J. Immol. 23:136-40, 1993; and Barclay et al., (In) The Leucocyte antigen factbooks, Academic press, London, 1993). These proteins are collectively known as the ‘transmembrane 4 superfamily’ (TM4) because they span the plasma membrane four times. The proteins known to belong to this family include, but are not limited to: mammalian antigen CD9 (MIC3), a protein involved in platelet activation and aggregation; mammalian leukocyte antigen CD37, expressed on B lymphocytes; mammalian leukocyte antigen CD53 (OX-44), which may be involved in growth regulation in hematopoietic cells; mammalian lysosomal membrane protein CD63 (Melanoma-associated antigen ME491; antigen AD1); mammalian antigen CD81 (cell surface protein TAPA-1), which may play an important role in the regulation of lymphoma cell growth; mammalian antigen CD82 (Protein R2; Antigen C33; Kangai 1 (KAI1)), which associates with CD4 or CD8 and delivers costimulatory signals for the TCR/CD3 pathway; mammalian antigen CD151 (SFA-1); Platelet-endothelial tetraspan antigen 3 (PETA-3); mammalian TM4SF2 (Cell surface glycoprotein A15; TALLA-1; MXS1); mammalian TM4SF3 (Tumor-associated antigen CO-029); mammalian TM4SF6 (Tspan-6; TM4-D); mammalian TM4SF7 (Novel antigen 2 (NAG-2); Tspan-4); mammalian Tspan-2; Mammalian Tspan-3 (TM4-A); mammalian Tetraspan NET-5; and Schistosoma mansoni and japonicum 23 Kd surface antigen (SM23/SJ23).[0603]
• Non-limiting examples of membrane proteins with six transmembrane domains include the EBV integral membrane protein LMP-1, and a splice variant of the mitochondrial protein hMRS3/4 (Li et al., Characterization of a novel human putative mitochondrial transporter homologous to the yeast mitochondrial RNA splicing proteins 3 and 4, FEBS Lett Apr. 6, 2001 494(1-2):79-84). Proteins with six transmembrane domains also include STEAP (six transmembrane epithelial antigens of the prostate) proteins (Afar et al., U.S. Pat. No. 6,329,503). The prototype member of the STEAP family, STEAP-1, appears to be a type IIIa membrane protein expressed predominantly in prostate cells in normal human tissues. Structurally, STEAP-1 is a 339 amino acid protein characterized by a molecular topology of six transmembrane domains and intracellular N- and C-termini, suggesting that it folds in a “serpentine” manner into three extracellular and two intracellular loops.[0604]
• Literally hundreds of 7-pass membrane proteins are known. G-protein coupled receptors (GPCRs), including without limitation beta-adreno receptors, adrenergic receptors, EDG receptors, adenosine receptors, B receptors for kinins, angiotensin receptors, and opiod receptors are of particular interest. GPCRs are described in more detail elsewhere herein.[0605]
• A non-limiting example of a protein with 9 transmembrane domains is Lipocalin-1 interacting membrane receptor (Wojnar et al., Molecular cloning of a novel Lipocalin-1 interacting human cell membrane receptor (LIMR) using phage-display, J Biol Chem 2001 3; [epub ahead of print]).[0606]
• Proteins with both transmembrane and anchoring domains are known. For example, AMPA receptor subunits have transmembrane domains and one membrane-anchoring domain.[0607]
• A variety of databases that describe known, and software programs that predict, membrane anchoring and transmembrane domains are available to those skilled in the art. See, for example Gcrdb.dba GCRDb [G Protein Coupled Receptor database], Tmbase.dba Tmbase [database of transmembrane domains], Prodom.srv ProDom [Protein domains], Tmap.srv TMAP [Protein transmembrane segments prediction], Tm7.srv TM7 [Retrieval of data on G protein-coupled receptors], and Memsat.sof MEMSAT [transmembrane structure prediction program].[0608]
• Quentin and Fichant (J Mol Microbiol Biotechnol 2000 2:501-4, ABCdb: an ABC transporter database) have described a database devoted to the ATP-binding cassette (ABC) protein domains (ABCdb), the majority of which energize the transport of compounds across membranes. In bacteria, ABC transporters are involved in the uptake of a wide range of molecules and in mechanisms of virulence and antibiotic resistance. In eukaryotes, most ABC transporters are involved in drug resistance, and many are associated with diseases. ABCdb can be accessed via the World Wide Web (http://ir2lcb.cnrs-mrs.fr/ABCdb/). See also Sanchez-Fernandez et al., The[0609]Arabidopsis thalianaABC protein superfamily: a complete inventory, J Biol Chem May 9, 2001 [epub ahead of print], and Rogers et al., The pleitropic drug ABC transporters fromSaccharomyces cerevisiae,J Mol Microbiol Biotechnol Apr. 3, 2001 (2):207-14.
• X.D. Functions and Activites of Membrane Proteins[0610]
• Non-limiting examples of membrane proteins include membrane-associated enzymes. Membrane-associated enzymes include but not limited to certain enzymes of the electron transport chain (ETC), antigenic proteins such as the major histocompatability (MHC) antigens, transport proteins, channels, hormone receptors, cytokine receptors, glucose permeases, gap junction proteins and bacteriorhodopsins.[0611]
• A “transport protein” or “transporter” is a type of membrane protein that allows substances to cross plasma membranes at a rate that is faster than what is found by diffusion alone. Some transport proteins expend energy to move substances (active transport). Many active transport proteins are ATPases (e.g., the Na[0612]⁺-K⁺ ATPase), or at least bind ATP by virtue of comprising an ATP-binding cassette (ABC) (see, e.g., Rogers et al., The pleitropic drug ABC transporters fromSaccharomyces cerevisiae,J Mol Microbiol Biotechnol 3:207-14, 2001). Nucleobase transporters are reviewed by De Koning and Diallinas (Nucleobase Transporters, Mol Membr Biol 17:75-94, 2000).
• A “channel protein” is a protein that facilitates the diffusion of molecules/ions across lipid membranes by forming a hydrophilic pore or “channel” that provides molecules/ions access through lipid membranes, which are generally hydrophobic. Channels are often multimeric, with the pore being formed by subunit-subunit interactions.[0613]
• A “receptor” is a molecular entity, typically a protein, that is displayed on the surface of a cell. A receptor is characterized by high affinity, often a specific binding of a specific substance, typically resulting in a specific biochemical or physiological effect.[0614]
• A “hormone” is a naturally occurring substance secreted by specialized cells that affects the metabolism or behavior of other cells having receptors for the hormone. Non-limiting examples of hormones having receptors include but are not limited to insulin, cytokines, steroid hormones, histamines, glucagon, angiotensin, catecholamines, low density lipids (LDLs), tumor necrosis factor alpha, tumor necrosis factor beta, estrogen, and testosterone.[0615]
• X.E. G-Protein-Coupled Receptors[0616]
• G protein-coupled receptors (GPCRs) constitute the most prominent family of validated drug targets within biomedical research and are thought to be involved in such diseases and disorders as heart disease, hypertension, cancer, obesiy, and depression and other mental illnesses. Over half of approved drugs elicit their therapeutic effects by selectively addressing members of this target family and more than 1000 sequences of the human genome encode for GPCRs containing the classical 7-pass membrane structure characteristic of this family of proteins (Marinissen, M. and J. S. Gutkind, G-protien-coupled receptors and signaling networks: emerging paradigms (Review), Trends. Phamacol. Sci. 22: 368-376, 2001). Many pharmacological drug companies are interested in the study of G-coupled proteins. It is possible to co-express a G-coupled protein receptor and its associated G-protein to study their pharmacological characteristics (Strosberg and Marullo, Functional expression of receptors in microorganisms. TiPS, 1992. 13: 95-98).[0617]
• G-protein-coupled receptors (GPCRs) are reviewed by Marinissen, M. and J. S. Gutkind, G-protien-coupled receptors and signaling networks: emerging paradigms. Trends. Phamacol. Sci. 22: 368-376, 2001; Sautel and Milligan, Molecular manipulation of G-protein-coupled receptors: a new avenue into drug discovery, Curr Med Chem 2000 889-96; Hibert et al., This is not a G protein-coupled receptor, Trends Pharmacol Sci 1993, 14:7-12; Wilson et al., Orphan G-protein-coupled receptors: the next generation of drug targets?, Br J Pharmacol 1998, 125:1387-92; Roth et al., G protein-coupled receptor (GPCR) trafficking in the central nervous system: relevance for drugs of abuse, Drug Alcohol Depend 1998, 51:73-85; Ferguson and Caron, G protein-coupled receptor adaptation mechanisms, Semin Cell Dev Biol 1998, 9:119-27; Wank, G protein-coupled receptors in gastrointestinal physiology. I. CCK receptors: an exemplary family, Am J Physiol 1998, 274:G607-13; Rohrer and Kobilka, G protein-coupled receptors: functional and mechanistic insights through altered gene expression. (Review), Physiol Rev 1998, 78:35-52; and Larhammar et al., The receptor revolution—multiplicity of G-protein-coupled receptors. (Review), Drug Des Discov 1993, 9:179-88.[0618]
• GPCR localization and regulation has been studied using GFP-comprising fusion proteins (Kallal and Benovic, Using green fluorescent proteins to study G-protein-coupled receptor localization and trafficking. (Review), Trends Pharmacol Sci 2000 21:175-80; and Ferguson, Using green fluorescent protein to understand the mechanisms of G-protein-coupled receptor regulation. (Review), Braz J Med Biol Res 1998, 31:1471-7); and by using chimeric GPCRs (Milligan and Rees, Chimaeric G alpha proteins: their potential use in drug discovery. (Review), Erratum in: Trends Pharmacol Sci Jun. 20, 1999 (6):252.[0619]
• GPCRs belong to a superfamily of at least 6 families of receptors, the most important of which is the main family, A. Members of the membrane protein gene superfamily of GPCRs have been characterized as having seven putative transmembrane domains. The transmembrane domains are believed to represent transmembrane alpha-helices connected by extracellular or cytoplasmic loops. A functional G-protein is a trimer which consists of a variable alpha subunit coupled to much more tightly-associated and constant beta and gamma subunits, although G-protein independent actions have been postulated (Marinissen, M. and J. S. Gutkind, G-protien-coupled receptors and signaling networks: emerging paradigms. Trends. Phamacol. Sci. 22: 368-376, 2001 Review). A variety of ligands have been identified which function through GPCRs. In general, binding of an appropriate ligand (e.g., bioactive lipids, ions, bioactive amines, photons, odorants, hormones, neurotransmitters, peptides, nucleosides, etc.) to a GPCR leads to the activation of the receptor. G-protein coupled receptors include a wide range of biologically active receptors, such as hormone, viral, growth factor and neuroreceptors. Typically, activation of a GPCR initiates the regulatory cycle of a corresponding G-protein. This cycle consists of GTP exchange for GDP, dissociation of the alpha and beta/gamma subunits, activation of the second messenger pathway by a complex of GTP and the alpha subunit of the G-protein, and return to the resting state by GTP hydrolysis via the innate GTPase activity of the G-protein alpha subunit A.[0620]
• GPCRs include, without limitation, dopamine receptors which bind to neuroleptic drugs used for treating psychotic and neurological disorders. Other examples of members of this family include calcitonin, adrenergic, endothelin, cAMP, adenosine, muscarinic, acetylcholine, serotonin, histamine, thrombin, kinin, follicle stimulating hormone, opsins and rhodopsins, odorant, cytomegalovirus receptors, and the like.[0621]
• Most GPCRs have single conserved cysteine residues in each of the first two extracellular loops which form disulfide bonds that are believed to stabilize functional protein structure. The seven transmembrane regions, each comprising conserved hydrophobic stretches of about 20 to 30 amino acids, are designated as TM1, TM2, TM3, TM4, TM5, TM6, and TM7. TM3 is also implicated in signal transduction.[0622]
• Although not wishing to be bound by any particular theory, it is believed that GPCRs participate in cell signaling through their interactions with heterotrimetric G-proteins composed of alpha, beta and gamma subunits (Marinissen, M. and J. S. Gutkind, G-protien-coupled receptors and signaling networks: emerging paradigms. Trends. Phamacol. Sci. 22:368-376, 2001). In some aspects of the invention, GPCRs and homologs are displayed on the surfaces of minicells.[0623]
• X.F. EDG Receptors and Other Sphingolipid-Binding Receptors[0624]
• The Endothelial Differentiation Gene (EDG) receptor family includes but is not limited to eight presently known GPCRs that have a high affinity to lipid ligands (Lynch et al., Life on the edg. Trends Pharmacol. Sci., 1999. 20: 273-5). These transmembrane receptors are found in several different tissues in different species. EDG receptors have been shown to be involved in calcium mobilization, activation of mitogen-activated protein kinase, inhibition of adenylate cyclase activation, and alterations of the cytoskelaton. The EDG family is divided into two different groups based on homology and ligand specificity. The EDG 2, 4, and 7 receptors are specific for the ligand lysophosphatidic acid (LPA) (An et al., Signaling Mechanism and molecular characteristics of G protein-coupled receptors for lysophosphatidic acid and sphingosine 1-phosphate. J. Cell Biochem, 30/31:147-157, 1998; Goetzl et al., Distinctive expression and functions of the type 4 endothelial differentiation gene-encoded G protein-coupled receptor for lysophosphatidic acid in ovarian cancer. Cancer Res., 59:5370-5, 1999). In contrast,[0625]EDG 1, 3, and 5 bind sphingosine-1-phosphate (S1P) (Zhang et al., Comparative analysis of three murine G-protein coupled receptors activated by sphingosine-1-phosphate. Gene, 227:89-99, 1999). EDG-6 is believed to interact with S1P (Yamazaki et al., Edg-6 as a putative sphingosine 1-phosphate receptor coupling to Ca²⁺⁺ signaling pathway. Biochem Phys Res Com, 268:583-589, 2000).
• Receptors that bind S1P and other sphingolipids are used in one aspect of the invention (for a review of some S1P-binding receptors, see Spiegel et al., Biochim. Biophys. Acta 1484:107-116, 2000). Such receptors include but are not limited to members of the EDG family of receptors (a.k.a. 1pA receptors, Chun, Crit. Rev. Neuro. 13:151-168, 1999), and isoforms and homologs thereof such as NRG1 and AGR16.[0626]
• EDG-1 was the first identified member of a class of G protein-coupled endothelial-derived receptors (EDG). Non-limiting examples of other EDG family members that also bind S1P include EDG-3 (a.k.a. ARG16; the rat homolog of EDG-3 is designated H218), EDG-5, EDG-6 and EDG-8. For reviews, see Goetzl et al., Adv. Exp. Med. Biol. 469:259-264, 1999; and Chun et al., Cell. Biochem. Biophys. 30:213-242, 1999).[0627]
• EDG-1 is described by Lee et al., (Ann. NY Acad. Sci. 845:19-31, 1998). Liu and Hla, The mouse gene for the inducible G-Protein-coupled receptor edg-1. Genomics, 1997, 43: p.15-24. Human EDG-1c genes and proteins are described in published PCT application WO 99/46277 to Bergsma et al.[0628]
• EDG-3 is described by Okamoto et al. (Biochem. Biophys. Res. Commun. 260:203-208, 1999) and An et al. (FEBS Letts. 417:279-282, 1997). See also An et al., J. Biol. Chem. 275:288-296, 2000.[0629]
• EDG-5 human and mammalian genes are described in U.S. Pat. No. 6,057,126 to Munroe et al. and published PCT application WO 99/33972 to Munroe et al. The rat homolog, H218, is described in U.S. Pat. No. 5,585,476 to MacLennan et al. Van Brocklyn et al., J. Biol. Chem. 274:4626-4632, 1999; and Gonda et al., Biochem. J. 337:67-75, 1999. See also An et al., J. Biol. Chem. 275:288-296, 2000.[0630]
• EDG-6 is described by Graler et al. (Genomics 53:164-169, 1998), Yamazaki et al. (Biochem. Biophys. Res. Commun. 268:583-589, 2000), and Van Brocklyn et al. (Sphingosine-1-phosphate is a ligand for the G protein-coupled receptor EDG-6, Blood 95:2624-9, 2000).[0631]
• EDG-8 from rat brain is described by Im et al., (J. Biol. Chem. 275:14281-14286, 2000). Homologs of EDG-8 from other species, including humans, may also be used in the present invention.[0632]
• The Mil receptor (Mil is an abbreviation for “miles apart”) binds SiP and regulates cell migration during vertebrate heart development. The Mil receptor of Zebrafish is described by Mohler et al. (J. Immunol. 151:1548-1561, 1993). Another SiP receptor is NRG1 (nerve growth factor regulated gene-1), the rat version of which has been identified (Glickman et al., Mol. Cel. Neurosci. 14:141-152, 1999).[0633]
• Receptors that bind sphingosylphosphoryl choline (SPC) are also used in this aspect of the invention. Such receptors include but are not limited to members of the SCaMPER family of receptors (Mao et al., Proc. Natl. Acad. Sci. U.S.A. 93:1993-1996, 1996; Betto et al., Biochem. J. 322:327-333, 1997). Some evidence suggests that EDG-3 may bind SPC in addition to S1P (Okamoto et al., Biochem. Biophys. Res. Commun. 260:203-208, 1999). Derivatives of EDG-3 that bind both S1P and SPC are used in one aspect of the invention.[0634]
• Receptors that bind lysophophatidic acid may be used in the present invention. These include EDG-2 (LPA1), EDG-4 (LPA2), EDG-7 (LPA3). See Moller et al., Expression and function of lysophosphatidic acid receptors in cultured rodent microglial cells, J Biol Chem 2001 May 4 [epub ahead of print]; Fukushima and Chun, The LPA receptors, Prostaglandins 64(1-4):21-32, 2001; Contos and Chun, The mouse 1p(A3)/Edg7 lysophosphatidic acid receptor gene: genomic structure, chromosomal localization, and expression pattern, Gene 267:243-53, 2001; Schulte et al., Lysophosphatidic acid, a novel lipid growth factor for human thyroid cells: over-expression of the high-affinity receptor edg4 in differentiated thyroid cancer, Int J Cancer 92249-56, 2001; Kimura et al., Two novel Xenopus homologs of mammalian LP(A1)/EDG-2 function as lysophosphatidic acid receptors in[0635]Xenopus oocytesand mammalian cells, J Biol Chem 276:15208-15, 2001; and Swarthout and Walling, Lysophosphatidic acid: receptors, signaling and survival (Review), Cell Mol Life Sci 57:1978-85, 2000.
• Examples of lysophospholipid receptors including, but not limited to EDG proteins, are disclosed in Fukushima et al. (Lysophospholipid receptors. Annu. Rev. Pharmacol. Toxicol. 41:507-534, 2001) Malek and Lee (Nrg-1 Belongs to the Endothelial Differentiation Gene Family of G Protein-coupled Sphingosine-1-phosphate Receptors, J. Biol. Chem. 276:5692-5699, 2001), Hla et al. (Sphingosine-1-phosphate signaling via the EDG-1 family of G-protein-coupled receptors (Review), Ann N Y Acad Sci 905:16-24, 2000; Chun, Lysophospholipid receptors: implications for neural signaling (Review), Crit Rev Neurobiol 13:151-68, 1999); and Chun et al. (A growing family of receptor genes for lysophosphatidic acid (LPA) and other lysophospholipids (LPs) (Review), Cell Biochem Biophys 30:213-42, 1999).[0636]
• XI. Recombinant DNA Expression[0637]
• In order to achieve recombinant expression of a fusion protein, an expression cassette or construct capable of expressing a chimeric reading frame is introduced into an appropriate host cell to generate an expression system. The expression cassettes and constructs of the invention may be introduced into a recipient eubacterial or eukaryotic cell either as a nonreplicating DNA or RNA molecule, which may be a linear molecule or, more preferably, a closed covalent circular molecule. Since such molecules are incapable of autonomous replication, the expression of the gene may occur through the transient expression of the introduced sequence. Alternatively, permanent expression may occur through the integration of the introduced DNA sequence into the host chromosome.[0638]
• XI.A. Recombinant DNA Expression Systems[0639]
• A variety of eubacterial recombinant DNA expression systems may be used to produce the fusion proteins of the invention. Host cells that may be used in the expression systems of the present invention are not strictly limited, provided that they are suitable for use in the expression of the fusion protein of interest and can produce minicells. Non-limiting examples of recognized eubacterial hosts that may be used in the present invention include bacteria such as[0640]E. coli,Bacillus, Streptonyces, Pseudomonas, Salmonella, Serratia, and the like.
• Eubacterial expression systems utilize plasmid and viral (bacteriophage) expression vectors that contain replication sites and control sequences derived from a species compatible with the host may be used. Suitable phage or bacteriophage vectors include λgt10, λgt11 and the like. Suitable virus vectors may include pMAM-neo, pKRC and the like. Appropriate eubacterial plasmid vectors include those capable of replication in[0641]E. coli(such as, by way of non-limiting example, pBR322, pUC118, pUC19, Co1E1, pSC101, pACYC 184, πrVX. See “Molecular Cloning: A Laboratory Manual” 1989). Bacillus plasmids include pC194, pC221, pT127, and the like (Gryczan, In:The Molecular Biology of the Bacilli,Academic Press, NY, pp. 307-329, 1982). Suitable Streptonyces plasmids include p1J101 (Kendall et al., J. Bacteriol. 169:4177-4183, 1987), and Streptomyces bacteriophages such as DREW check this C31 (Chater et al., In: Sixth International Symposium on Actinomycetales Biology, Akademiai Kaido, Budapest, Hungary, pp. 45-54, 1986). Pseudomonas plasmids are reviewed by John et al. (Rev. Infect. Dis. 8:693-704, 1986), and Izaki (Jpn. J. Bacteriol. 33:729-742, 1978). See also Brent et al., “Vectors Derived From Plasmids,” Section II, and Lech et al. “Vectors derived from Lambda and Related Bacteriophages” Section III, inChapter 1 ofShort Protocols in Molecular Biology,2nd Ed., Ausubel et al., eds., John Wiley and Sons, New York, 1992, pages 1-13 to 1-27; Lech et al. “Vectors derived from Lambda and Related Bacteriophages” Section III and Id. pages 1-28 to page 1-52.
• To express a protein, including but not limited to a fusion protein, in a eubacterial cell, it is necessary to operably link the ORF encoding the protein to a functional eubacterial or viral promoter. Such promoters may be either constitutive or, more preferably, regulatable (i.e., inducible or derepressible). Examples of constitutive promoters include the int promoter of bacteriophage lambda, the bla promoter of the beta-lactamase gene sequence of pBR322, and the cat promoter of the chloramphenicol acetyl transferase gene sequence of pPR325, and the like. Examples of inducible eubacterial promoters include the major right and left promoters of bacteriophage lambda (PL and PR), the trp, recA, lacZ, lacl, and gal promoters of[0642]E. coli,the alpha-amylase (Ulmanen et al., J. Bacteriol. 162:176-182, 1985) and the sigma-28-specific promoters ofB. subtilis(Gilman et al., Gene Sequence 32:11-20, 1984), the promoters of the bacteriophages of Bacillus (Gryczan, in: The Molecular Biology of the Bacilli, Academic Press, Inc., NY, 1982), and Streptomzyces promoters (Ward et al., Mol. Gen. Genet. 203:468-478, 1986). Eubacterial promoters are reviewed by Glick (Ind. Microbiot. 1:277-282, 1987), Cenatiempo (Biochimie 68:505-516, 1986), and Gottesman (Ann. Rev. Genet. 18:415-442, 1984).
• Proper expression also requires the presence of a ribosome-binding site upstream of the gene sequence-encoding sequence. Such ribosome-binding sites are disclosed, for example, by Gold et al. (Ann. Rev. Microbiol. 35:365-404, 1981). The selection of control sequences, expression vectors, transformation methods, and the like, are dependent on the type of host cell used to express the gene. As used herein, “cell”, “cell line”, and “cell culture” may be used interchangeably and all such designations include progeny. Thus, the words “transformants” or “transformed cells” include the primary subject cell and cultures derived therefrom, without regard to the number of transfers. It is also understood that all progeny may not be precisely identical in DNA content, due to deliberate or inadvertent mutations. However, as defined, mutant progeny have the same functionality as that of the originally transformed cell.[0643]
• Mammalian expression systems utilize host cells such as HeLa cells, cells of fibroblast origin such as VERO or CHO-K1, or cells of lymphoid origin and their derivatives. Preferred mammalian host cells include SP2/0 and J558L, as well as neuroblastoma cell lines such as IMR 332, which may provide better capacities for correct post-translational processing. Non-limiting examples of mammalian extrachromosomal expression vectors include pCR3.1 and pcDNA3.1, and derivatives thereof including but not limited to those that are described by and are commercially available from Invitrogen (Carlsbad, Calif.).[0644]
• Several expression vectors are available for the expression of polypeptides in mammalian host cells. A wide variety of transcriptional and translational regulatory sequences may be employed, depending upon the nature of the host. The transcriptional and translational regulatory signals may be derived from viral sources, such as adenovirus, bovine papilloma virus, cytomegalovirus (CMV), simian virus, or the like, where the regulatory signals are associated with a particular gene sequence which has a high level of expression. Alternatively, promoters from mammalian expression products, such as actin, collagen, myosin, and the like, may be employed. Transcriptional initiation regulatory signals may be selected which allow for repression or activation, so that expression of the gene sequences can be modulated. Of interest are regulatory signals that are temperature-sensitive since, by varying the temperature, expression can be repressed or initiated, or are subject to chemical (such as metabolite) regulation.[0645]
• Preferred eukaryotic plasmids include, for example, BPV, vaccinia, SV40, 2-micron circle, and the like, or their derivatives. Such plasmids are well known in the art (Botstein et al., Miami Wntr. Symp. 19:265-274, 1982; Broach, in: The Molecular Biology of the Yeast Saccharomyces: Life Cycle and Inheritance, Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., p. 445-470, 1981; Broach, Cell 28:203-204, 1982; Bollon et al., J. Clin. Hematol. Oncol. 10:39-48, 1980; Maniatis, In: Cell Biology: A Comprehensive Treatise, Vol. 3, Gene Sequence Expression, Academic Press, NY, pp. 563-608, 1980).[0646]
• Expression of polypeptides in eukaryotic hosts generally involves the use of eukaryotic regulatory regions. Such regions will, in general, include a promoter region sufficient to direct the initiation of RNA synthesis. Preferred eukaryotic promoters include, for example, the promoter of the mouse metallothionein I gene sequence (Hamer et al., J. Mol. Appl. Gen. 1:273-288, 1982); the TK promoter of Herpes virus (McKnight, Cell 31:355-365, 1982); the SV40 early promoter (Benoist et al., Nature (London) 290:304-31, 1981); and the yeast gal4 gene sequence promoter (Johnston et al., Proc. Natl. Acad. Sci. (USA) 79:6971-6975, 1982; Silver et al., Proc. Natl. Acad. Sci. (USA) 81:5951-5955, 1984).[0647]
• Expression sequences and elements are also required for efficient expression. Non-limiting examples include Kozak and IRES elements in eukaryotes, and Shine-Delgarno sequences in prokaryotes, which direct the initiation of translation (Kozak, Initiation of translation in prokaryotes and eukaryotes. Gene, 1999. 234: 187-208; Martinez-Salas et al., Functional interactions in internal translation initiation directed by viral and cellular IRES elements, Jour. of Gen. Virol. 82:973-984, 2001); enhancer sequences; optioanl sites for repressor and inducers to bind; and recognition sites for enaymes that cleave DNA or RNA in a site-specific manner. Translation of mRNA is generally initiated at the codon which encodes the first methionine; if so, it is preferable to ensure that the linkage between a eukaryotic promoter and a preselected ORF does not contain any intervening codons that encode a methionine (i.e., AUG). The presence of such codons results either in the formation of a fusion protein with an uncharacterized N-terminal extension (if the AUG codon is in the same reading frame as the ORF) or a frame-shift mutation (if the AUG codon is not in the same reading frame as the ORF).[0648]
• XI.B. Expression of Membrane ProteinsPresently, the most commonly used expression systems for the expression of integral membrane proteins are eukaryotic and eubacterial whole cell expression systems. Although minicells have been used to express several eubacterial membrane proteins, the production of non-eubacterial membrane proteins has not been reported. One aspect of the invention is the discovery that the minicell expression system can be made to express and preferably display integral membrane proteins from non-eubacterial organisms.[0649]
• Some commonly used expression systems include in vitro systems, such as the Rabbit Reticulocyte Lysate System and[0650]E. coliS30 Extract System (both available from Promega) (Zubay, Methods Enz. 65:856, 1980) and in vivo systems, such as eukaryotic cell culture expression, and bacterial expression systems. Although this is not an exhaustive list, these systems are representative.
• The Rabbit Reticulocyte Lysate system utilizes a cell lysate that contains all the enzymes required for transcription and translation to drive protein expression, and is a good in vitro system for producing small amounts of labeled and unlabeled protein. However, this system is not well-suited for the production of large quantities of proteins and is limited to soluble proteins as there are no membranes in which to incorporate membrane proteins.[0651]
• In eukaryotic cell culture systems, expression vectors suited for expression in host eukaryotic cells are transfected into cultured cells and protein is translated from mRNA produced from the vector DNA template Kaufman, Overview of vector design for mammalian gene expression. Mol Biotechnol, 2001. 16: 151-160; Lee, et al., Heterologous gene expression in avian cells: Potential as a producer of recombinant proteins. J Biomed Sci, 1999. 6: 8-17; Voorma et al., Initiation of protein synthesis in eukaryotes. Mol Biol Rep, 1994. 19: 139-45). Cells can then either be harvested to prepare at least partially purified proteins or proteins produced from the expression element can be studied in the host cell environment.[0652]
• Regarding membrane proteins, such systems have limitations. Primary cell lines are difficult to maintain and are short lived. Immortalized cell lines divide indefinitely, but have been altered in many ways and can be unpredictable. The transfection efficiency is very low in most eukaryotic cells and some cell types are refractory to transformation. Moreover, other proteins are expressed in these cells along with the protein of interest. This can cause difficulties when performing certain experiments and when attempting to immunoprecipitate the protein. Good experimental data are difficult to obtain from studies such as binding assays (because of high background due to endogenous proteins), and crystal determination of protein structure (because it is difficult to obtain enough purified protein to efficiently form crystals).[0653]
• Bacterial expression systems are generally similar to that of the eukaryotic expression systems in that they both use the host cell enzymes to drive protein expression from recombinant expression vectors (Cornelis, P., Expressing genes in different[0654]Escherichia colicompartments. Curr Opin Biotechnol, 2000. 11: p. 450-454; Laage and Langosch, Strategies for prokaryotic expression of eukaryotic membrane proteins. Traffic, 2001. 2: 99-104; Pines, O. and M. Inouye, Expression and secretion inE. coli.Mol Biotechnol, 1999. 12: 25-34).
• In bacterial expression systems, bacterial cells are transformed with expression elements, and transcription and translation is driven from a bacterial promoter. Bacteria divide very rapidly and are easy to culture; it is relatively easy to produce a large number of bacteria in a short time. Moreover, incorporation of expression elements vector into bacterial cells is efficient. Transformed cells can be isolated that arise from a single bacterium. Cultures of transformed cells are thus genetically identical and all cells in the culture will contain the expression element. However, there are proteins that are not suitable for expression in bacteria because of differences between eukaryotic cells and bacterial cells in transcription, translation, and post-translational modification.[0655]
• The[0656]E. coliwhole cell expression system has been used to express functional integral membrane proteins. For a review, see Strosberg, Functional expression of receptors in microorganisms. TiPS, 1992. 13: 95-98. Examples of mammalian integral membrane proteins that have been expressed inEscherichia coliinclude rat alpha-2B-adrenoceptors (Xia et al., Functional expression of rat β2B-adrenoceptor inE. coli.Euro J. Pharma, 1993. 246: 129-133) and the human beta2-adrenergic receptor (Marullo et al., Human β2-adrenergic receptors expressed inEscherichia colimembranes retain their pharmacological properties. Proc. Natl. Acad. Sci. USA, 1988. 85: 7551-7555). In some of these studies, the integral membrane proteins were not only expressed inE. coliexpression systems, but also retained their pharmacological properties. This allows for binding studies to be performed with minimal background signal (“noise”) from host cell proteins. It has also been shown that signal sequences (the short hydrophobic amino acid sequence at the N-terminus of integral membrane proteins that signals the transport of the protein to the membrane) from mammalian cells may be functional in theE. colisystem.
• As is discussed herein, the expression of membrane proteins such as GPCRs, ion channels, and immuno-receptors in minicells, and their incorporation into the membranes thereof, allows for the study and use of such non-eubacterial membrane proteins. The minicell system of the invention is particularly well-suited for the study and expression of EDG proteins because of the lipid nature of the ligands for these receptors. The identification of ligand binding kinetics and biochemistry of these receptors because of the physiochemical properties of the lipid ligands (LPA and S1P), which results in high non-specific binding (Lee et al., Sphingosine-1-phosphate is a ligand for the G protein-coupled receptor EDG-1. Science, 1998. 279: 1552-1555; Van Brocklyn et al., Sphingosine-1-phosphate is a ligand for the G protein-coupled receptor EDG-6. Blood, 2000. 95: 2624-2629; Liu et al., Edg-1, the G protein-coupled receptor for sphingosine-1-phosphate, is essential for vascular maturation. J. Clin. Investigation, 2000. 106: 951-961).[0657]
• It is believed, for example, that in the case of the ion channels, the minicell expression system is less cumbersome then procedures that are presently used to study properties of ion channels, such as, e.g., reconstitution studies (Montal, Molecular anatomy and molecular design of channel proteins. FASEB J., 1990. 4: p. 2623-2635). Ionic conditions both inside and outside of minicells can be manipulated in various ways, and the properties of an ion channel that is expressed in a minicell, and factors that activate or modulate the activities of the channel, can be studied. Binding and kinetic studies are performed on ligand mediated ion channels. This type of study is enhanced when the ion channel is able to interact specifically with its ligand and has a low background of non-specific binding from the endogenous proteins. This can be accomplished by making the minicells into protoplasts or poroplasts in which the ligand-activated ion channels in the inner membrane are exposed to the external environment and have better access to their specific ligand.[0658]
• A “recombinant expression system” (or simply “expression system”) is one that directs the production of exogenous gene products in a host cell or minicell of choice. By “expressed” it is meant that a gene product of interest (which can be a protein or nucleic acid) is produced in the expression system of choice.[0659]
• Host cells (and/or minicells) harboring an expression construct are components of expression systems. An “expression vector” is an artificial nucleic acid molecule into which an exogenous ORF encoding a protein, or a template of a bioactive nucleic acid can be inserted in such a manner so as to be operably linked to appropriate expression sequences that direct the expression of the exogenous gene. By the term “operably linked” it is meant that the part of a gene that is transcribed is correctly aligned and positioned with respect to expression sequences that promote, are needed for and/or regulate this transcription. The term “gene product” refers to either a nucleic acid (the product of transcription, reverse transcription, or replication) or a polypeptide (the product of translation) that is produced using the non-vector nucleic acid sequences as a template.[0660]
• In some applications, it is preferable to use an expression construct that is an episomal element. If the episomal expression construct expresses (or, preferably in some applications, over-expresses) a an ORF that has been incorporated into the episomal expression construct, the minicells will direct the production of the polypeptide encoded by the ORF. At the same time, any mRNA molecules transcribed from a chromosomal gene prior to minicell formation that have been transferred to the minicell are degraded by endogenous RNases without being replaced by new transcription from the (absent) bacterial chromosome.[0661]
• Chromosomally-encoded mRNAs will not be produced in minicells and will be “diluted” as increasing amounts of mRNAs transcribed from the episomal element are generated. A similar dilution effect is expected to increase the relative amount of episomally-generated proteins relative to any chromosomally-encoded proteins present in the minicells. It is thus possible to generate minicells that are enriched for proteins encoded by and expressed from episomal expression constructs.[0662]
• Although by no means exhaustive, a list of episomal expression vectors that have been expressed in eubacterial minicells is presented in Table 4.[0663]
• It is also possible to transform minicells with exogenous DNA after they have been prepared or separated from their parent cells. For example, phage RNA is produced in minicells after infection by lambda phage (Witkiewicz and Taylor, Ribonucleic acid synthesis after adsorption of the bacteriophage lambda on[0664]Escherichia coliminicells, Acta Microbiol Pol A 7:21-4, 1975), even though replication of lambda phage may not occur in minicells (Witkiewicz and Taylor, The fate of phage lambda DNA in lambda-infected minicells, Biochim Biophys Acta 564:31-6, 1979).
• Because it is the most characterized minicell-producing species, many of these episomal elements have been examined in minicells derived from[0665]E. coli.It is understood by practitioners of the art, however, that many episomal elements that are expressed inE. colialso function in other eubacterial species, and that episomal expression elements for minicell systems in other species are available for use in the invention disclosed herein.
• In one aspect of the invention, eukaryotic and archeabacterial minicells are used for expression of membrane proteins, particularly in instances where such desirable proteins have enhanced or altered activity after they undergo post-translational modification processes such as phosphorlyation, proteolysis, mystrilation, GPI anchoring and glycosylation. Expression elements comprising expression sequence operably linked to ORFs encoding the membrane proteins of interest are transformed into eukaryotic cells according to methods and using expression vectors known in the art. By way of non-limiting example, primary cultures of rat cardiomyocytes have been used to produce exogenous proteins after transfection of expression elements therefor by electroporation (Nakajima et al., Expression and characterization of Edg-1 receptors in rat cardiomyocytes: Calcium deregulation in response to sphingosine-1-phosphate, Eur. J. Biochem. 267: 5679-5686, 2000).[0666]
• Yeast cells that produce minicells are transformed with expression elements comprising an ORF encoding a membrane protein operably linked to yeast expression sequences. Cells that harbor a transferred expression element may be selected using a gene that is part of the expression element that confers resistant to an antibiotic, e.g., neomycin.[0667]
• Alternatively, in one aspect of the invention, bacterial minicells are prepared that contain expression elements that are prepared from shuttle vectors. A “shuttle vector” has sequences required for its replication and maintenance in cells from two different species of organisms, as well as expression elements, at least one of which is functional in bacterial cells, and at least one of which is functional in yeast cells. For example,[0668]E. coli-yeast shuttle vectors are known in the art and include, by way of non-limiting example, those derived from Yip, Yrp, Ycp and Yep. PreferredE. coli-yeast shuttle vectors are episomal elements that can segregrate into yeast minicells (i.e., Yrp, Ycp and Yep. Particularly preferred are expression vectors of the Yep (yeast episomal plasmid) class, and other derivatives of the naturally occurring yeast plasmid known as the 2 μm circle. The latter vectors have relatively high transformation frequencies and are stably maintained through mitosis and meiosis in high copy number.

  TABLE 4
  Episomal Elements That Segregate IntoEscherichia coliMinicells

  EPISOMAL ELEMENT	REFERENCES
  Plasmids
  R6K, R1DRD19	Nesvera et al., Folia Microbiol. (Praha) 23: 278-285 (1978)
  PSC101	Fox et al., Blood 69: 1394-1400 (1987)
  PBR322	Fox et al., Blood 69: 1394-1400 (1987)
  F element	Cohen et al., Proc. Natl. Acad. Sci. 61: 61-68 (1968);
  	Khachatourians G.G., Biochim. Biophys. Acta. 561: 294-300 (1979)
  NR1	Hochmannova et al., Folia Microbiol. (Praha) 26: 270-276
  R6δ1	Hochmannova et al., Folia Microbiol. (Praha) 26: 270-276
  PTTQ18	Rigg et al., Arch. Oral. Biol. 45: 41-52 (2000)
  PGPR2.1	Rigg et al., Arch. Oral. Biol. 45: 41-52 (2000); expresses cell
  	surface antigen ofP. gingivalis
  “mini-plasmid” derivative of	Firshein et al., J. Bacteriol. 150: 1234-1243 (1982)
  RK2
  ColE1	Rashtchian et al., J. Bacteriol. 165: 82-87 (1986); Witkiewicz et al.,
  	Acta. Microbiol. Pol. A 7: 21-24 (1975)
  PSC101	Rashtchian et al., J. Bacteriol. 165: 82-87 (1986); Curtiss, Roy, III,
  	U.S. Pat. No. 4,190,495; Issued February 26, 1980
  pACYC184	Chang et al., J. Bacteriol. 134: 1141-1156 (1978); Rose, Nucleic
  	Acids Res 16: 355 (1988)
  Co1Ib, Co1Ib7 DRD&	Skorupska et al., Acta. Microbiol. Pol.A 8: 17-26 (1976)
  pUC19	Heighway et al., Nucleic Acids Res. 17: 6893-6901 (1989)
  R-plasmid	Hochmannova et al., Folia Microbiol. (Praha) 25: 11-15 (1980)
  PCR1	Hollenberg et al., Gene 1: 33-47 (1976); yeast shuttle vector
  Bacteriophage
  Lambda	Witkiewicz et al., Acta. Microbiol. Pol. A 7: 21-24 (1975)
  M13	Staudenbauer et al., Mol. Gen. Genet. 138: 203-212 (1975)
  T7	Libby, Mech Ageing Dev. 27: 197-206 (1984)
  P1	Curtiss, Roy, III, U.S. Pat. No. 4,190,495; Issued 2/26/80;
  	J Bacteriol 1995; 177: 2381-6, Partition of P1 plasmids inEscherichia
  	colimukB chromosomal partition mutants, Funnell and Gagnier.

• For expression of membrane proteins, and/or other proteins of interest in the recipient cell, ORFs encoding such proteins are operably linked to eukaryotic expression sequences that are appropriate for the recipient cell. For example, in the case of[0669]E. coli-yeast shuttle vectors, the ORFs are operably linked to expression sequences that function in yeast cells and/or minicells. In order to assess the effectiveness of a gene delivery vehicle, or a gene therapy expression element, an ORF encoding a detectable polypeptide (e.g., GFP, beta-galactosidase) is used. Because the detectable polypeptide is operably linked to eukaryotic expression elements, it is not expressed unless it has been transferred to its recipient (eukaryotic) cell. The signal from the detectable polypeptide thus correlates with the efficiency of gene transfer by a gene delivery agent, or the degree of expression of a eukaryotic expression element.
• Gyuris and Duda (High-efficiency transformation of Saccharoymces cells by bacterial minicell protoplast fusion, Mol Cel Biol 6:329507, 1986) allegedly demonstrated the transfer of plasmid molecular by fusing minicell protoplasts with yeast protoplasts. Gyuris and Duda state that 10% of[0670]Saccharomyces cerevisiaecells were found to contain transforming DNA sequences. However, the plasmids did not contain eukaryotic expression elements, were not shuttle vectors, and genetic expression of the plasmids in yeast cells was not examined.
• XII. Uses of Minicells in Research[0671]
• XII.A. In General[0672]
• The minicells of the invention can be used in research applications such as, by way of non-limiting example, proteomics, physiology, chemistry, molecular biology, physics, genetics, immunology, microbiology, proteomics, virology, pathology, botany, and neurobiology. Research applications include but are not limited to protein-ligand binding studies, competitive inhibition studies, structural studies, protein interaction studies, transfection, signaling studies, viral interaction studies, ELISA, antibody studies, gel electrophoresis, nucleotide acid) applications, peptide production, cell culture applications, cell transport studies, isolation and separation studies, chromatography, labeling studies, synthesis of chemicals, chemical cross linking, flow cytometry, nanotechnology, micro switches, micro-machines, agricultural studies, cell death studies, cell-cell interactions, proliferation studies, and protein-drug interactions. Minicells are applicable to research applications involving, by way of non-limiting example, the elucidation, manipulation, production, replication, structure, modeling, observations, and characterization of proteins.[0673]
• The types of proteins that can be involved in research applications of minicells can be either soluble proteins or membrane bound proteins, and include but are not limited to receptors (e.g., GPCRs, sphingolipid receptors, neurotransmitter receptors, sensory receptors, growth factor receptors, hormone receptors, chemokine receptors, cytokine receptors, immnunological receptors, and compliment receptors, FC receptors), channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases.), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN), chemotactic/adhesion proteins (e.g., ICAM11, selectins, CD34, VCAM-1, LFA-1,VLA-1), and chimeric/fusion proteins (e.g., proteins in which a normally soluble protein is attached to a transmembrane region of another protein).[0674]
• Research products are designed for any specific type of application. These products may be packaged and distributed as, by way of non-limiting example, kits, chemicals, solutions, buffers, powders, solids, filters, columns, gels, matrixes, emulsions, pellets, capsules, and aerosols. Kits and reagents for certain research applications may be required by regulatory agency to be labeled “research use only” in order to indicate that the reagents are not intended for use in humans.[0675]
• XII.B. Transfection[0676]
• Transfection is the process of introducing genetic material into eukaryotic and archaebacterial cells using biological, biochemical or physical methods. This process allows researchers to express and study target proteins in cultured cells (research use) as well as to deliver genetic material to cells in vivo or ex vivo systems (gene therapy). There are a variety of techniques which allow for the introduction and expression of proteins into target cells. These include mechanical transfection (Biolistic particles and Electroporation), calcium phosphate, DEAE-dextran/polybrene, viral based techniques and lipid based techniques.[0677]
• The genetic material and/or nucleic acid to be delivered can be, by way of non-limiting example, nucleic acids that repair damaged or missing genes, nucleic acids for research applications, nucleic acids that kill a dysfunctional cell such as a cancer cell, antisense oligonucleotides to reduce or inhibit expression of a gene product, genetic material that increases expression of another gene, nucleotides and nucleotide analogs, peptide nucleic acids (PNAs), tRNAs, rRNAs, catalytic RNAs, RNA:DNA hybrid molecules, and combinations thereof.[0678]
• The genetic material may comprise a gene expressing a protein. exemplary proteins include, but are not limited to, receptors (e.g., GPCRs, sphingolipid receptors, neurotransmitter receptors, sensory receptors, growth factor receptors, hormone receptors, chemokine receptors, cytokine receptors, immunological receptors, and compliment receptors, FC receptors), channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN), chemotactic/adhesion proteins (e.g., ICAM11, selecting, CD34, VCAM-1, LFA-1,VLA-1), and chimeric/fusion proteins (e.g., proteins in which a normally soluble protein is attached to a transmembrane region of another protein).[0679]
• A minicell that is used to deliver therapeutic agents may comprise and display a binding moiety. By way of non-limiting example, binding moieties used for particular purposes may be a binding moiety directed to a compound or moiety displayed by a specific cell type or cells found predominantly in one type of tissue, which may be used, among other things, to target minicells and their contents to specific cell types or tissues. A preferred binding moiety is an antibody or antibody derivative. Other binding moieties include, but are not limited to, receptors, enzymes, ligands, binding peptides, fusion proteins, small molecules conjugated to transmembrane proteins, ligands conjugated to transmembrane proteins, viral fusion proteins, and fusion/chimeric proteins.[0680]
• A minicell containing genetic material may be to a target cell by methods including, but not limited to, receptor mediated endocytosis, cell fusion, or phagocytosis (Aderem et al., Mechanism of Phagocytosis in Macrophages, Annu. Rev. Immunol. 17:593-623, 1999). The minicell gene delivery system is used to deliver genetic material in culture for research applications as well as to cells in vivo as part of gene therapy or other therapeutic applications.[0681]
• By way of non-limiting example, a minicell may express a protein such as invasin to induce receptor mediated endocytosis (Pepe et al., “[0682]Yersinia enterocoliticainvasin: A primary role in the initiation of infection,” Proc. Natl. Acad. Sci. U.S.A. 90:6473-6477, 1993; Alrutz et al., “Involvement of focal adhesion kinase in invasin-mediated uptake,” Proc. Natl. Acad. Sci. U.S.A. 95:13658-13663, 1998). Invasin interacts with the Beta2 Integrin protein and causes it to dimerize. Upon dimerization the Beta2 Integrin signals for an endocytotic event. Thus a minicell expressing the invasin protein will be taken up by cells expressing Beta2 Integrin via endocytosis.
• Another non-limiting example of the minicell gene delivery and transfection system using invasin involves the expression of invasin following a targeting event. In this example, a minicell expresses a targeting protein that is capable of bringing the minicell in contact with a specific target cell. Upon contact with the target cell, the minicell will be induced to transcribe and translate invasin. The induction is accomplished via signaling events or with a transcription factor dimerization event. The minicells can be engineered to contain targeting proteins that induce protein expression only upon contact with a specific target cell. By way of non-limiting example, the invasin is expressed only at the target cell where it induces endocytosis, thus preventing the minicell from entering any cell but the target cell.[0683]
• Proteins can be induced and expressed post contact with target cells include but are not limited to antibodies and antibody derivatives, receptors, enzymes, ligands, binding peptides, fusion proteins, small molecules conjugated to transmembrane proteins, ligands conjugated to transmembrane proteins, viral fusion proteins, antibiotics, apoptotic proteins, hormones, toxins, poisons, and fusion/chimeric proteins.[0684]
• Another non-limiting example of gene delivery or transfection using the minicell involves the use of the type III secretion apparatus of bacteria. The type III secretion apparatus is expressed in the minicell and used to transfer genetic material to a target cell.[0685]
• Another non-limiting example of gene delivery and transfection using minicells involves minicells that have been engineered to contain anionic lipids or cationic lipids (Axel et al., “Toxicity, Uptake Kinetics and Efficacy of New Transfection Reagents: Increase of Oligonucleotide Uptake,” Jour. of Vasc. Res. 040:1-14, 2000). Many types of lipids have been shown to induce or enhance transfection and gene delivery in a variety of cell types. Minicells containing such lipids could be used to transfer genetic material to specific cell types. Minicells can also be engineered to express targeting proteins that would allow the minicell to associate tightly with a target cell, which will facilitate the lipid interactions and gene transfer.[0686]
• Another non-limiting example of gene delivery or transfection using minicells involves the use of ligands to induce receptor mediated endocytosis. By way of non-limiting example, the ligand is expressed on the surface of the minicell, or is attached to the surface of the minicell. A minicell containing genetic material is then able to associate with a target cell expressing the target receptor for the ligand. The receptor/ligand interaction will result in the endocytosis of the minicell into the target cell where the minicell would release and deliver the genetic material.[0687]
• Another non-limiting example of gene delivery or transfection using minicells involves the use of fusion proteins, such as but not limited to viral capsid proteins. In this example the fusion protein would be expressed or attached to the outside of the minicell. The fusion protein would then induce fusion of a target cell with the minicell upon contact. The contact could be initiated via random non-targeting events or via the use of specific targeting proteins. In both cases the end result would be the fusion of the minicell with a target cell and the delivery of the genetic material.[0688]
• XII.C. Non-Limiting Examples of Research Applications of Minicells[0689]
• XII.C.1. Phage Interactions With Bacterial Membranes[0690]
• One non-limiting example of a research application for minicells would be the study of phage interactions with a bacterial membrane. The minicells could be used to study how phage associate and enter into a host bacterium. Another non-limiting example is the research application of minicells is to study isolated cell signaling pathways. The proteins of a signaling pathway could be expressed in the minicell and the signal cascade could be monitored. Another non-limiting example of research applications is the use of minicells to determine how recombination events occur. In this example the minicell is used to provide an environment to study the recombination event between two episomal plasmid DNA units.[0691]
• XII.C.2. Matrices[0692]
• Another non-limiting example of a research application of minicells is to form chromatography matrices for immunoprecipitation, isolation and separation techniques. The minicell can express and display target proteins with binding activity, including but not limited to antibodies and antibody derivatives. The minicell is then used to generate a matrix and loaded in a column or tube. The solution to be separated is mixed or passed through the column allowing the minicell to bind its target. The minicells are then separated away with the attached substance.[0693]
• XII.C.3. Mutagenesis[0694]
• Another non-limiting example of a research application for minicells involves site directed mutagenesis studies of target proteins. In this application minicells are generated to express target proteins with various mutations and deletions to study if function is compromised, enhanced or has an altered specificity for ligand binding.[0695]
• XII.C.4. Metabolic pathways[0696]
• Another non-limiting example of research applications for minicells involves the study of metabolic rates of proteins and metabolites. The minicell can be generated to express metabolic pathways and the kinetics and function of that pathway can be studied.[0697]
• XII.C.5. Cell Free Production of Proteins[0698]
• Another non-limiting example of a research application for minicells involves uses in cell free production of functional proteins (Jermutus et al., Recent advances in producing and selecting functional proteins by using cell-free translation, Current Opinion in Biotechnology 9:534-548, 1999). Minicells can be prepared as a reagent used to prepare compositions for in vitro translation. As is described in detail elsewhere herein, the composition of minicells can be manipulated so as to be enriched for particular proteins or nulceic acids, including those involved in protein translation and folding and/or modification of the proteins so produced into functional forms, i.e., forms having the activity of the corresponding protein as it is isolated from natural sources. Non-limiting examples of such proteins and nulceic acids are ribosomal RNAs, ribosomal proteins, tRNAs, and the like.[0699]
• XII.C.6. Assays[0700]
• Minicells could also be used in manual, semi-automated, automated and/or robotic assays for the in vitro determinations of the compounds of interest including, by way of non-limiting example, ligands, proteins, small molecules, bioactive lipids, drugs, heavy metals, and the like in environmental samples (e.g., air, water, soil), blood, urine or tissue of humans or samples from non-human organisms (e.g., plants, animals, protists) for the purpose of quantifying one or more compounds in a sample. A non-limiting example of this type of ressearch applications is the expression on the surfaces of the minicells of a receptor such as the receptor that binds a toxin produced by Baccillus anthracis. The protein, protective antigen (PA), is a 82.7 kDa protein that binds one of the secreted anthrax toxins, lethal factor (LF) (see Price, B. et al., Infection and Immunity 69: 4509-4515. 2001). Minicells expressing the PA protein could be used to detect LF in an environmental sample or in human blood, urine or tissue for the purposes of determining the presence of anthax. As a non-limiting example, a competitive binding assay or an antibody-based assay could be used to indicate binding of LF in the environmental or tissue sample. Another non-limiting example is the use of PA-expressing minicells in a lateral flow diagnostic where interaction between the minicells and the LF-containing sample is indicated by the presence of a colored reaction product on a test strip.[0701]
• XIII. Minicell-Based Delivery of Biologucally Active Agents[0702]
• XIII.A. General Considerations[0703]
• The minicells of the invention are capable of encapsulating and/or loading into a membrane a variety of substances, including but not limited to biologically active agents, including but not limited to diagnostic and therapeutic agents. Biologically active agents include, but are not limited to, nucleic acids, e.g., DNA, RNA, gene therapy constructs, ribozymes, antisense and other synthetic oligonucleotides including those with chemical modifications; peptide nucleic acids (PNAs); proteins; synthetic oligopeptides; peptomimetics; small molecules; radioisotopes; antibiotics; antibodies and antibody derivatives; and combinations and/or prodrugs of any of the preceding.[0704]
• The surface of a minicell may be chemically altered in order to have certain properties that are desirable for their use as drug delivery agents. By way of non-limiting example, minicells may be chemically conjugated to polyethylene glycol (PEG), which provides for “stealth” minicells that are not taken as well and/or as quickly by the reticuloendothelial system (RES). Other compounds that may be attached to minicells include without limitation polysaccharides, polynucleotides, lipopolysaccharides, lipoproteins, glycosylated proteins, synthetic chemical compounds, and/or combinations of any of the preceding.[0705]
• A minicell that is used to deliver therapeutic agents may comprise and display a binding moiety. By way of non-limiting example, binding moieties used for particular purposes may be a binding moiety directed to a compound or moiety displayed by a specific cell type or cells found predominantly in one type of tissue, which may be used, among other things, to target minicells and their contents to specific cell types or tissues. A preferred binding moiety is an antibody or antibody derivative, which are described in deatil elsewhere herein. Other binding moieties include, but are not limited to, receptors, enzymes, ligands, binding peptides, fusion proteins, small molecules conjugated to transmembrane proteins, ligands conjugated to transmembrane proteins, viral fusion proteins, and fusion/chimeric proteins.[0706]
• XIII.B. Cellular Uptake[0707]
• In addition to binding moieties, proteins and other compounds that induce or enhance the uptake or fusion of the minicell with the target gene can be displayed on the surface of a minicell for applications involving the delivery of therapeutic agents, gene therapy, and/or transfection or other research applications. See, generally,[0708]Adhesion Protein Protocols,Vol. 96, Dejana, E. and Corada, M., eds., Humana Press, 1999.
• XIII.B.1. Cellular Uptake Sequences from Eukaryotic Cells[0709]
• Eukaryotic adhesion receptors, which mediate intercellular adhesion, can be used as agents or targets for cellular uptake. There are at least three distinct classes of adhesive molecules that leukocytes employ during their adhesive interactions (a) integrins, including but not limited to LEC-CAMS/Selectins (ELAM-1, LAM-1/Leu8/TQ1, and GMP140/PADGEM); (b) those belonging to the immunoglobulin superfamily including but not limited to CD2(LFA-2), CD3/TCR, CD4, CD8, CD28, CD44,CD54 (ICAM-1), ICAM-2, CD58 (LFA-3), VCAM-1,B7; and (c) Class I and II Major Histocompatability Antigens (MHC).[0710]
• The adhesion receptors that belong to the integrin family and control intercellular interactions are of partciular interest. At least ten different structurally related cell surface heterodimeric (alpha and beta complexes) molecules have been defined as integrins and further classified into subfamilies (Springer T. A., 1990, Nature 346:425-434; Hynes, R. O., 1987, Cell 48:549-554; Moller, G. Editor, 1990, Immunol. Rev. 114.: 1-217). Each subfamily has a unique beta subunit, designated integrin beta1 (CD29), integrin beta2 (CD18), and integrin beta3 (CD61), each of which can associate with multiple alpha subunits, each with at least one di-valent cation binding site. The integrin family includes receptors for extracellular matrix components such as fibronectin, laminin, vitronectin, and collagen which recognize Arg-Gly-Asp in their ligands and utilize the betal or beta3 subunits (Springer T. A., 1990, Nature 346:425-434; Hynes, R. O., 1987, Cell 48:549-554; Hemler, M. E., 1988, Immunol. Today 9:109-113; Patarroyo, M., and Makgoba, M. W., 1989, Scand. J. Immunol. 30:129-164; Moller, G. Editor, 1990, Immunol. Rev. 11.4:1-217). There are at least six distinct alpha subunits alphal (CD49a), alpha2 (CD49b), alpha3 (CD49c), alpha4 (CD49d), alpha5 (CD49e), and alpha (CD49f) capable of associating with betal (CD29). The betal integrins are expressed on many nonhematopoietic and leukocyte cell types and are thought to play an active role in tissue organization by binding to extracellular matrix components found in many tissues and in the basement membranes underlying muscles, nervous system, epithelium and endothelium. While the expression of many betal integrins on leukocytes requires consistent activation, their expression on nonhematopoietic cells does not (Hemler, M. E., 1988, Immunol. Today 9:109-113; Patarroyo, M., and Makgoba, M. W., 1989, Scand. J. Immunol. 30:129-164). The complexity of the integrin family has been increased by the discovery of novel beta subunits beta3 (CD61), beta4 and beta5 that can associate with alpha 4, alpha 6, and alpha V subunits (Springer T. A., 1990, Nature 346:425-434; Hemler, M. E., 1988, Immunol. Today 9:109-113). This combinatorial use of alpha and beta subunits confers considerable diversity in ligand recognition and also helps regulate communications between the inside and outside of the cell.[0711]
• By way of non-limiting example, a minicell display an adhesion receptor, or a fusion protein that has a transmembrane domain linked to a functional portion of an adhesion receptor. Such minicells will bind to cells displaying the ligand for the adhesion receptor.[0712]
• XIII.B.2. Cellular Uptake Sequences from Prokaryotes[0713]
• Bacterial adhesion proteins are another source of polypetides that are used to stimulate uptake of minicells. See, generally,[0714]Handbook of Bacterial Adhesion: Priniciples, Methods, and Applications,Yuehuei H. An; Richard J. Friedman, eds., Humana Press, 2000; and Hultgren et al., “Bacterial Adhesions and Their Assembly,” Chapter 150 in:Eschericia coli and Salmonella typhimurium: Cellular and Molecular Biology,2^ndEd., Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1996, Volume 2, pages 1903-1999, and references cited therein.
• By way of non-limiting example, a minicell may express a protein such as invasin to induce receptor mediated endocytosis (Pepe et al.,[0715]Yersinia enterocoliticainvasin: A primary role in the initiation of infection, Proc. Natl. Acad. Sci. U.S.A. 90:6473-6477, 1993; Alrutz et al., Involvement of focal adhesion kinase in invasin-mediated uptake, Proc. Natl. Acad. Sci. U.S.A. 95:13658-13663, 1998). Invasin interacts with the Beta2 Integrin protein and causes it to dimerize. Upon dimerization the Beta2 Integrin signals for an endocytotic event. Thus a minicell expressing the invasin protein will be taken up by cells expressing Beta2 Integrin via endocytosis.
• As another non-limiting example, the pneumococcal adhesin protein CpbA interacts with the human polyimmunoglobulin receptor (hpIgR) as either a part of the outer surface of a bacterial cell or as a free molecule Zhang et al. (Cell 102:827-837, 2000). The regions of CpbA:hpIgR interaction were mapped using a series of large peptide fragments derived from CpbA. CpbA (Swiss-Prot Accession No. 030874) contains a choline binding domain containing residues 454-663 and two N-terminal repetitive regions called R1 and R2 that are contained in residues 97-203 and 259-365, respectively. Polypeptides containing R1 and R2 interact with hpIgR, whereas polypeptides containing other sequences from CpbA do not bind to hpIgR. The R1 and/or R2 sequences of the CpbA polypeptide, and/or essentially identical, substantially identical, or homologous amino acid sequences, are used to facilitate the uptake of minicells by cells.[0716]
• Another non-limiting example of gene delivery or transfection using the minicell involves the use of the type III secretion apparatus of bacteria. The type III secretion apparatus is expressed in the minicell and used to transfer genetic material to a target cell.[0717]
• Other non-limiting examples of a minicell gene delivery and transfection targeting moiety are ETA (detoxified exotoxin a) protein delivery element described in U.S. Pat. No. 6,086,900 to Draper; Interalin and related proteins from Listeria species (Galan, Alternative Strategies for Becoming an Insider: Lessons from the Bacterial World, Cell 103:363-366,2000); Intimin from pathogenic[0718]E. colistrains (Frankel et al., Intimin and the host cell—is it bound to end in Tir(s)? Trends in Microbiology 9:214-218); and SpeB, streptococcal pyrogenic exotoxin B (Stockbauer et al., A natural variant of the cysteine protease virulence factor of group A Streptococcus with an arginine-glycine-aspartic acid (RGD) motif preferentially binds human integrins α_vβ₃and α_IIbβ₃Proc. Natl. Acad. Sci. U.S.A. 96:242-247, 1999).
• XIII.B.3. Cellular Uptake Sequences from Viruses[0719]
• Cellular uptake sequences derived from viruses include, but are not limited to, the VP22 protein delivery element derived from herpes simplex virus-1 and vectors containing sequences encoding the VP22 protein delivery element are commercially available from Invitrogen (Carlsbad, Calif.; see also U.S. Pat. No. 6,017,735 to Ohare et al.); and the Tat protein delivery element derived from the amino acid sequence of the Tat protein of human immunodeficiency virus (HIV). See U.S. Pat. Nos. 5,804,604; 5,747,641; and 5,674,980.[0720]
• XIII.B.4. Lipids[0721]
• Another non-limiting example of gene delivery and transfection using minicells involves minicells that have been engineered to contain anionic lipids or cationic lipids (Axel et al., Toxicity, Uptake Kinetics and Efficacy of New Transfection Reagents: Increase of Oligonucleotide Uptake, Jour. of Vasc. Res. 040:1-14, 2000). Many types of lipids have been shown to induce or enhance transfection and gene delivery in a variety of cell types. Minicells containing such lipids could be used to transfer genetic material to specific cell types. Minicells can also be engineered to express targeting proteins that would allow the minicell to associate tightly with a target cell, which will facilitate the lipid interactions and gene transfer.[0722]
• Another non-limiting example of gene delivery or transfection using minicells involves the use of ligands to induce receptor mediated endocytosis. By way of non-limiting example, the ligand is expressed on the surface of the minicell, or is attached to the surface of the minicell. A minicell containing genetic material is then able to associate with a target cell expressing the target receptor for the ligand. The receptor/ligand interaction will result in the endocytosis of the minicell into the target cell where the minicell would release and deliver the genetic material.[0723]
• Another non-limiting example of gene delivery or transfection using minicells involves the use of fusion proteins, such as but not limited to viral capsid proteins. In this example the fusion protein would be expressed or attached to the outside of the minicell. The fusion protein would then induce fusion of a target cell with the minicell upon contact. The contact could be initiated via random non-targeting events or via the use of specific targeting proteins. In both cases the end result would be the fusion of the minicell with a target cell and the delivery of the genetic material.[0724]
• XIII.C. Post-Targeting Expression of Cellular Uptake Sequences[0725]
• Another non-limiting example of the minicell gene delivery and transfection system using invasin involves the expression of invasin following a targeting event. In this example, a minicell expresses a targeting protein that is capable of bringing the minicell in contact with a specific target cell. Upon contact with the target cell, the minicell will be induced to transcribe and translate invasin. The induction is accomplished via signaling events or with a transcription factor dimerization event. The minicells can be engineered to contain targeting proteins that induce protein expression only upon contact with a specific target cell. By way of non-limiting example, the invasin is expressed only at the target cell where it induces endocytosis, thus preventing the minicell from entering any cell but the target cell.[0726]
• Proteins can be induced and expressed post contact with target cells include but are not limited to antibodies and antibody derivatives, receptors, enzymes, ligands, binding peptides, fusion proteins, small molecules conjugated to transmembrane proteins, ligands conjugated to transmembrane proteins, viral fusion proteins, antibiotics, apoptotic proteins, hormones, toxins, poisons, and fusion/chimeric proteins.[0727]
• XIII. D. Intracellular Targeting and Organellar Delivery[0728]
• After delivery to and entry into a targeted cell, a minicell may be designed so as to be degraded, thereby releasing the therapeutic agent it encapsulates into the cytoplasm of the cell. The minicell and/or therapeutic agent may include one or more organellar delivery elements, which targets a protein into or out of a specific organelle or organelles. For example, the ricin A chain can be included in a fusion protein to mediate its delivery from the endosome into the cytosol. Additionally or alternatively, delivery elements for other organelles or subcellular spaces such as the nucleus, nucleolus, mitochondria, the Golgi apparatus, the endoplasmic reticulum (ER), the cytoplasm, etc. are included Mammalian expression constructs that incorporate organellar delivery elements are commercially available from Invitrogen (Carlsbad, Calif.: pShooter™ vectors). An H/KDEL (i.e., His/Lys-Asp-Glu-Leu sequence) may be incorporated into a fusion protein of the invention, preferably at the carboxy-terminus, in order to direct a fusion protein to the ER (see Andres et al., J. Biol. Chem. 266:14277-142782, 1991; and Pelham, Trends Bio. Sci. 15:483-486, 1990).[0729]
• Another type of organellar delivery element is one which directs the fusion protein to the cell membrane and which may include a membrane-anchoring element. Depending on the nature of the anchoring element, it can be cleaved on the internal or external leaflet of the membrane, thereby delivering the fusion protein to the intracellular or extracellular compartment, respectively. For example, it has been demonstrated that mammalian proteins can be linked to i) myristic acid by an amide-linkage to an N-terminal glycine residue, to ii) a fatty acid or diacylglycerol through an amide- or thioether-linkage of an N-terminal cysteine, respectively, or covalently to iii) a phophotidylinositol (PI) molecule through a C-terminal amino acid of a protein (for review, see Low, Biochem. J. 244:1-13, 1987). In the latter case, the PI molecule is linked to the C-terminus of the protein through an intervening glycan structure, and the PI then embeds itself into the phopholipid bilayer; hence the term “GPI” anchor. Specific examples of proteins know to have GPI anchors and their C-terminal amino acid sequences have been reported (see Table 1 and FIG. 4 in Low, Biochemica et Biophysica Acta, 988:427-454, 1989; and Table 3 in Ferguson, Ann. Rev. Biochem., 57:285-320, 1988). Incorporation of GPI anchors and other membrane-targeting elements into the amino- or carboxy-terminus of a fusion protein can direct the chimeric molecule to the cell surface.[0730]
• XIII.E. Minicell-Based Gene Therapy[0731]
• The delivery of nucleic acids to treat diseases or disorders is known as gene therapy (Kay et al., Gene Therapy, Proc. Natl. Acad. Sci. USA 94:12744-12746, 1997). It has been proposed to use gene therapy to treat genetic disorders as well as pathogenic diseases. For reviews, see Desnick et al., Gene Therapy for Genetic Diseases, Acta Paediatr. Jpn. 40:191-203, 1998; and Bunnell et al., Gene Therapy for Infectious Diseases, Clinical Microbiology Reviews 11:42-56, 1998).[0732]
• Gene delivery systems use vectors that contain or are attached to therapeutic nucleic acids. These vectors facilitate the uptake of the nucleic acid into the cell and may additionally help direct the nucleic acid to a preferred site of action, e.g., the nucleus or cytoplasm (Wu et al., “Delivery Systems for Gene Therapy,” Biotherapy 3:87-95, 1991). Different gene delivery vectors vary with regards to various properties, and different properties are desirable depending on the intended use of such vectors. However, certain properties (for example, safety, ease of preparation, etc.) are generally desirable in most circumstances.[0733]
• The minicells of the invention may be used as delivery agents for any therapeutic or diagnostic agent, including without limitation gene therapy constructs. Minicells that are used as delivery agents for gene therepay constructs may, but need not be, targeted to specific cells, tissues, organs or systems of an organism, of a pathogen thereof, using binding moieties as described in detail elsewhere herein.[0734]
• In order to enhance the effectiveness of gene delivery vectors in, by way of non-limiting example, gene therapy and transfection, it is desirable in some applications of the invention to target specific cells or tissues of interest (targeted cells or tissues, respectively). This increases the effective dose (the amount of therapeutic nucleic acid present in the targeted cells or tissues) and minimizes side effects due to distribution of the therapeutic nucleic acid to other cells. For reviews, see Peng et al., “Viral Vector Targeting,” Curr. Opin. Biotechnol. 10:454-457, 1999; Gunzburg et al., “Retroviral Vector Targeting for Gene Therapy,” Cytokines Mol. Ther. 2:177-184, 1996.; Wicklam, “Targeting Adenovirus,” Gene Ther. 7:110-114, 2000; Dachs et al., “Targeting Gene Therapy to Cancer: A Review,” Oncol. Res. 9:313-325, 1997; Curiel, “Strategies to Adapt Adenoviral Vectors for Targeted Delivery,” Ann NY Acad. Sci. 886:158-171, 1999; Findeis et al., “Targeted Delivery of DNA for Gene Therapy via Receptors,” Trends Biotechnol. 11:202-205, 1993.[0735]
• Some targeting strategies make use of cellular receptors and their natural ligands in whole or in part. See, for example, Cristiano et al., “Strategies to Accomplish Gene Delivery Via the Receptor-Mediated Endocytosis Pathway,” Cancer Gene Ther., Vol. 3, No. 1, pp. 49-57, January-Feburary 1996.; S. C. Philips, “Receptor-Mediated DNA Delivery Approaches to Human Gene Therapy,” Biologicals, Vol. 23, No. 1, pp. 13-6, March 1995; Michael et al., “Strategies to Achieve Targeted Gene Delivery Via the Receptor-Mediated Endocytosis Pathway,” Gene Ther., Vol. 1, No. 4, pp. 223-32, July 1994; Lin et al., “Antiangiogenic Gene Therapy Targeting The Endothelium-Specific Receptor Tyrosine Kinase Tie2,” Proc. Natl. Acad. Sci., USA, Vol. 95, pp. 8829-8834, 1998. Sudimack et al., “Targeted Drug Delivery Via the Folate Receptor,” Adv. Drug Deliv., pp. 147-62, March 2000; Fan et al., “Therapeutic Application of Anti-Growth Factor Receptor Antibodies,” Curr. Opin. Oncol., Vol. 10, No. 1, pp. 67-73, January 1998; Wadhwa et al., “Receptor Mediated Glycotargeting,” J. Drug Target, Vol. 3, No. 2, pp. 111-27, 1995; Perales et al., “An Evaluation of Receptor-Mediated Gene Transfer Using Synthetic DNA-Ligand Complexes,” Eur. J. Biochem, Vol. 1, No 2, pp. 226, 255-66, December 1994; Smith et al., “Hepatocyte-Directed Gene Delivery by Receptor-Mediated Endocytosis,” Semin Liver Dis., Vol. 19, No. 1, pp. 83-92, 1999.[0736]
• Antibodies, particularly single-chain antibodies, to surface antigens specific for a particular cell type may also be used as targeting elements. See, for example, Kuroki et al., “Specific Targeting Strategies of Cancer Gene Therapy Using a Single-Chain Variable Fragment (scFv) with a High Affinity for CEA,” Anticancer Res., pp. 4067-71, 2000; U.S. Pat. No. 6,146,885, to Dornburg, entitled “Cell-Type Specific Gene Transfer Using Retroviral Vectors Containing Antibody-Envelope Fusion Proteins”; Jiang et al., “In Vivo Cell Type-Specific Gene Delivery With Retroviral Vectors That Display Single Chain Antibodies,” Gene Ther. 1999, 6:1982-7; Engelstadter et al., “Targeting Human T Cells By Retroviral Vectors Displaying Antibody Domains Selected From A Phage Display Library,” Hum. Gene Ther. 2000, 11:293-303; Jiang et al., “Cell-Type-Specific Gene Transfer Into Human Cells With Retroviral Vectors That Display Single-Chain Antibodies,” J. Virol 1998,72:10148-56; Chu et al., “Toward Highly Efficient Cell-Type-Specific Gene Transfer With Retroviral Vectors Displaying Single-Chain Antibodies,” J. Virol 1997, 71:720-5; Chu et al., “Retroviral Vector Particles Displaying The Antigen-Binding Site Of An Antibody Enable Cell-Type-Specific Gene Transfer,” J. Virol 1995, 69:2659-63; and Chu et al., “Cell Targeting With Retroviral Vector Particles Containing Antibody-Envelope Fusion Proteins,” Gene Ther. 1994, 1:292-9.[0737]
• Minicells are used to deliver DNA-based gene therapy to targeted cells and tissues. Double minicell transformants are used not only to target a particular cell/tissue type (e.g. HIV-infected T-cells) but are also engineered to fuse with and enter targeted cells and deliver a protein-based toxin (e.g., antibiotic, or pro-apoptotic gene like Bax), an antisense expression construct (e.g., antisense to a transcription factor), or antisense oligonucleotides (e.g., antisense to an anti-apoptotic gene such as Bcl-2. The doubly-transformed minicells express not only these cell death promoters, but also only target particular cells/tissues, thus minimizing toxicity and lack of specificity of gene therapy vectors. By “doubly-transformed” it is meant that the minicell comprises 2 expression elements, one eubacterial, the other eukaryotic. Alternaively, shuttle vectors, which comprise eubacterial and eukaryotic expression elementsin one vector, may be used.[0738]
• Minicell-based gene therapy is used to deliver expression plasmids that could correct protein expression deficiencies or abnormalities. As a non-limiting example, minicell inhalants are targeted to pulmonary alveolar cells and are used to deliver chloride transporters that are deficient or otherwise material in cystic fibrosis. Protein hormone deficiencies (e.g., dwarfism) are corrected by minicell expression systems (e.g., growth hormone expression in pituitary cells). Duchene's muscular dystrophy is characterized by a mutation in the dystrophin gene; this condition is corrected by minicell-based gene therapy. Angiogenesis treatment for heart patients is made effective by FGF or VGEF-producing minicells targeted to the heart. In this case, plasmid-driven over-expression of these grown factors is preferred.[0739]
• XIV. Therapeutic Uses of Minicells[0740]
• In addition to minicell-based gene therapy, minicells can be used in a variety of therapeutic modalities. Non-limiting examples of these modalities include the following applications.[0741]
• XIV.A. Diseases and Disorders[0742]
• Diseases and disorders to which the invention can be applied include, by way of non-limiting example, the following.[0743]
• Diseases and disorders that involve the respiratory system, such as cystic fibrosis, lung cancer and tumors, asthma, pathogenic infections, allergy-related diseases and disorders, , such as asthma; allergic bronchopulmonary aspergillosis; hypersensitivity pneumonia, eosinophilic pneumonia; emphysema; bronchitis; allergic bronchitis bronchiectasis; cystic fibrosis; hypersensitivity pneumotitis; occupational asthma; sarcoid, reactive airway disease syndrome, interstitial lung disease, hyper-eosinophilic syndrome, parasitic lung disease and lung cancer, asthma, adult respiratory distress syndrome, and the like;[0744]
• Diseases and disorders of the digestive system, such as those of the gastrointestinal tract, including cancers, tumors, pathogenic infections, colitis; ulcerative colitis, diverticulitis, Crohn's disease, gastroenteritis, inflammatory bowel disease, bowel surgery ulceration of the duodenum, a mucosal villous disease including but not limited to coeliac disease, past infective villous atrophy and short gut syndromes, pancreatitis, disorders relating to gastroinstestinal hormones, Crohn's disease, and the like;[0745]
• Diseases and disorders of the skeletal system, such as spinal muscular atrophy, rheumatoid arthritis, osteoarthritis, osteoporosis, multiple myeloma-related bone disorder, cortical-striatal-spinal degeneration, and the like;[0746]
• Autoimmune diseases, such as Rheumatoid arthritis (RA), multiple sclerosis (MS), Sjogren's syndrome, sarcoidosis, insulin dependent diabetes mellitus (IDDM), autoimmune thyroiditis, reactive arthritis, ankylosing spondylitis, scleroderma, polymyositis, dermatomyositis, psoriasis, vasculitis, Wegener's granulomatosis, Crohn's disease and ulcerative colitis amyotrophic lateral sclerosis, multiple sclerosis, autoimmune gastritis, systemic lupus erythematosus, autoimmune hemolytic anemia, autoimmune neutropenia, systemic lupus erythematosus, graft vs. host disease, bone marrow engraftment, some cases of Type I diabetes, and the like;[0747]
• Neurological diseases and disorders, such as depression, bipolar disorder, schizophrenia, Alzheimer's disease, Parkinson's disease, familial tremors, Gilles de la Tourette syndrome, eating disorders, Lewy-body dementia, chronic pain and the like;[0748]
• Pathological diseases and resultant disorders such as bacterial infections such as infection by Escherichia, Shigella, Salmonella; sepsis, septic shock, and bacteremia; infections by a virus such as HIV, adenovirus, smallpox virus, hepatovirus, and the like; and AIDS-related encephalitis, HIV-related encephalitis, chronic active hepatitis, and the like;[0749]
• Proliferative disease and disorders, such as acute lymphoblastic leukemia, acute myelogenous leukemia, chronic myelogenous leukemia, metastatic melanoma, Kaposi's sarcoma, multiple myeloma, breast cancer, anal cancer, vulvar cancer, and the like; and[0750]
• Various diseases, disorders and traumas including, but not limited to, apoptosis mediated diseases, inflammation, cerebral ischemia, myocardial ischemia, aging, sarcoidosis, granulomatous colitis, scleroderma, degenerative diseases, necrotic diseases, alopecia, neurological damage due to stroke, diffuse cerebral cortical atrophy, Pick disease, mesolimbocortical dementia, thalamic degeneration, Huntington chorea, cortical-basal ganglionic degeneration, cerebrocerebellar degeneration, familial dementia with spastic paraparesis, polyglucosan body disease, Shy-Drager syndrome, olivopontocerebellar atrophy, progressive supranuclear palsy, dystonia musculorum deformans, Hallervorden-Spatz disease, Meige syndrome, acanthocytic chorea, Friedreich ataxia, Holmes familial cortical cerebellar atrophy, Gerstmann-Straussler-Scheinker disease, progressive spinal muscular atrophy, progressive balbar palsy, primary lateral sclerosis, hereditary muscular atrophy, spastic paraplegia, glomeralonephritis, chronic thyroiditis, Grave's disease, thrombocytopenia, myasthenia gravis, psoriasis, peroneal muscular atrophy, hypertrophic interstitial polyneuropathy, heredopathia atactica polyneuritiformis, optic neuropathy, and ophthalmoplegia.[0751]
• A variety of diseases and disorders caused or exacerbated by pathogens may be treated using the invention. For a comprehensive description of pathogens and associated diseases and disorders, see Zinsser Microbiology, 20th Ed., Joklik, ed., Appelton-Century-Crofts, Norwalk, Conn., 1992, and references cited therein.[0752]
• Minicells could also be used for replacement therapy (via gene therapy) in a variety of conditions known to be caused by protein or proteins that are either absent (e.g. Duchene's Muscular Dystrophy), reduced in level (Dwarfism) or abberant (Sickle-cell anemia).[0753]
• For a comprehensive description of diseases and disorders that may be treated using the invention, see The Merck Manual of Diagnosis and Therapy, 17th Ed., Beers et al., eds.; published edition, Merck and Co., Rahway, N.J., 1999; on-line edition, Medical Services, Usmedsa, USHH, http://www.merck.com/pubs/mmanual/, and references cited therein.[0754]
• XIV.B. Removal of Toxins and Pathogens by Selective Absorption[0755]
• When introduced into the bloodstream of an animal, receptor-displaying minicells bind and absorb toxic compounds, thereby removing such compounds from the general circulation. A therapeutic benefit ensues as the bound toxic compound cannot access the cells upon which it would otherwise exert its toxic effect.[0756]
• Minicells expressing receptors for toxic substances are introduced IV in order to remove those toxins from the blood. One non-limiting example is in the treatment of sepsis. In one embodiment, a fusion protein is formed from the transmembrane domain of the EGF receptor or toxR and a known soluble receptor for LPS (lipopolysaccharide), such as the LBP (lipopolysaccharide binding protein) or the extracellular domain of CD14 receptor protein, both of which bind the LPS bacterial endotoxin. These minicells inactivate LPS by initially binding to it and preventing LPS binding to naturally occurring CD14 receptors on heart cells and other cells involved in the endotoxic shock response. Eventually, the minicell-LPS complex is cleared from the blood by macrophages and other components of the immune system.[0757]
• In another embodiment, minicells expressing receptors for toxic drugs (e.g., morphine) are used to treat drug overdoses. In other embodiments, minicells of the invention are used to express receptors to venoms (e.g., snake venom) or poisons (e.g., muscarinic receptor expression for the treatment of muscarine poisoning). In other embodiments, minicells of the invention expressing EDGRs are used to clear the blood of toxins and other undesirable compounds.[0758]
• As another non-limiting example, minicells that bind pathogens are used to treat disease. Minicells, and pathogens bound thereto, may be ingested by human neutrophils and thus serve as an adjuvant to therapeutic processes mediated by neutrophils (Fox et al., Fate of the DNA in plasmid-containing[0759]Escherichia coliminicells ingested by human neutrophils, Blood 69:1394-400, 1987). In a related modality, minicells are used to bind compounds required for the growth of a pathogen.
• XIV.C. Antiviral Therapy[0760]
• In one modality, minicells of the invention are used as “sponges” for the selective absorption of any viral particle in the body. Without being limited to the following examples, minicells expression receptors or antibodies selectively directed against viruses such as HIV, Hepatitis B and smallpox are used.[0761]
• For the treatment of viremia, viruses are cleared from the blood by absorption during dialysis or by IV injection of minicells expressing targets for viral receptors. As the minicells interact with blood-borne virus particles, there is an initial reduction of host cell infection by virtue of the minicell-viral complexes that are formed. Since viral particles attach to and/or enter the minicell, they are not active because of the lack of machinery needed for viral replication in the minicells. The virus infected minicells are then cleared from the system by macrophages and processed by the immune system.[0762]
• Certain retroviruses that infect particular host cells express viral proteins on the surfaces of the infected cells. HIV infection of T-cells is one non-limiting example of this. The viral protein, GP120, is expressed on the surfaces of infected T-cells (Turner et al., Structural Biology of HIV, J. Mol. Biol. 285:1-32, 1999). Minicells expressing CD4 act as anti-GP120 minicells not only to target virus particles in an infected patient, but also to identify infected T-cells. It may be desirable to also express co-receptors such as CCR5, CXR4 or ARD (Dragic, An overview of the determinants of CCR5 and CXCR4 co-receptor function, J. Gen. Virol. 82:1807-1814, 2001). The minicells are then used to kill the infected T-cells, or to inhibit viral replication and/or virion assembly.[0763]
• In another non-limiting example of anti-pathogen therapy, minicells can by used to express bacterial surface antigens on their surfaces that facilitate cellular uptake of the minicell by intracellular pathogens such as[0764]Mycobacterium tuberculosis(the causative agent of tuberculosis), Rickettsiae, or viruses. In this “smart sponge” approach, selective absorption is accompanied by internalization of the pathogen by minicells. Destruction of the pathogen follows as a result of a combination of intraminicell digestion of pathogens and/or by the eventual processing of the virus-containing minicell by the cellular immune system of the patient.
• XIV.D. Antibacterial and Antiparasitic Applications[0765]
• Minicells may be used to kill pathogenic bacteria, protozoans, yeast and other fungi, parasitic worms, viruses and other pathogens by mechanisms that either do or do not rely on selective absorption. Antibiotics can be delivered to pathogenic organisms after first being targeted by the proteins or small molecules on the surfaces of the minicells that promote binding of the minicells to the surfaces of the pathogen. Fusion or injection of minicell contents into the pathogenic cell can result in the death or disablement of the pathogen and thus lower the effective dose of an antibiotic or gene therapeutic agent. Delivery of antibiotics tethered to or encapsulated by the minicells will reduce the effective dose of an antibiotic and will reduce its elimination by the renal system. In the case of delivering encapsulated molecules (e.g., antibiotics), purified/isolated minicells expressing membrane-bound proteins for targeting can be incubated with the molecules in vitro prior to administration. This would be particularly applicable to the use of protoplast minicells or poroplast minicells that have their outer membrane and cell wall or outer membrane only removed, respectively, thus facilitating the diffusion of the small molecule into the intact minicell.[0766]
• Without being limited by the following example, minicells can be use as antibacterial agents by expressing on the surfaces of the minicells antigens, receptors, antibodies, or other targeting elements that will target the minicell to the pathogenic organism and facilitate the entry of plasmids, proteins, small molecules in order to gain access to or entry into the organism. Antibiotics may be encapsulated by minicells post isolation from the parent strain so that the antibiotic will not be effective against the minicell-producing bacteria itself. Since minicells are not able to reproduce, the antibiotic will not be lethal to the minicell delivery vehicle, but only to the targeted pathogen. In another non-limiting example, lyosgenic factors e.g., complement may be expressed on the surfaces of the minicells or encapsulated by same as to promote lysis of the pathogen.[0767]
• Minicells can also be engineered to express toxic proteins or other elements upon binding to the pathogen. Induction of minicell protein expression can be an event that is coincident with targeting or triggered by minicell binding to the target pathogen, thus making minicells toxic only when contact is made with the pathogenic organism. Minicells can be engineered to express fusion/chimeric proteins that are tethered to the membrane by transmembrane domains that have signaling moieties on the cytoplasmic surfaces of the minicells, such as kinases or transcription factors. In one non-limiting example, a minicell fusion membrane-bound protein could be expressed containing an extracellular domain with a receptor, scFv, or other targeting protein that binds to the pathogen. The second segment of the chimera could be a transmembrane domain of a protein such as the EGF receptor or ToxR (that would tether the fusion protein to the membrane). Importantly, the cytoplasmic domain of the fusion protein could be a kinase that phosphorylates a bacterial transcription factor present in the minicell or could be fused to a transcription factor that would be expressed on the cytoplasmic surface of the minicell. The expression plasmid that was previously introduced into the minicells would then be activated by promoters utilizing the activated bacterial transcription factor pre-existing in the minicells or that which may be introduced by the minicell. Without being limited to the following example, the binding event could be signaled by a fusion protein containing elements of a receptor (e.g., EGF) or by an adhesion protein (e.g., an integrin) that require oligomerization. In the example of the use of integrins, bacterial or other transcription factors that also require dimerization could be cloned as fusion proteins such that the binding event would be signaled by a dimerization of two or more identical recombinant chimeric proteins that have association-dependent transcription factors tagged to the C-terminus of the fusion protein. The minicells would only be toxic when contact is made with the pathogen.[0768]
• The proposed mechanism of induction coincident with targeting is not limited to the antiparasitic uses of minicells but can be used in other therapeutic situations where minicells are used to express proteins of therapeutic benefit when directed against eucaryotic cells of the organism (e.g., kill cancer cells with protein toxins expressed only after binding of the minicell to the cancer cell).[0769]
• Transfer of DNA-containing plasmids or other expression element, antisense DNA, etc. may be used to express toxic proteins in the target cells or otherwise inhibit transcription and/or translation in the pathogenic organism or would otherwise be toxic to the cell. Without being limited by the following example, minicells can be used to transfer plasmids expressing growth repressors, DNAses, or other proteins or peptides (e.g., pro-apoptotic) that would be toxic to the pathogen.[0770]
• XIV.E. Cancer Therapy[0771]
• Fusion proteins expressed in minicells are used for cancer therapy. In a non-limiting example, phage display antibody libraries are used to clone single chain antibodies against tumor-associated (tumor-specific) antigens, such as MUCH-1 or EGFvIII. Fusion proteins expressing these antibodies, and further comprising a single-pass transmembrane domain of an integral membrane protein, are used to “present” the antibody to the surface of the minicells. Injected minicells coated with anti-tumor antibodies target the tumor and deliver pro-apoptotic genes or other toxic substances to the tumor. The minicells are engulfed by the tumor cells by processes such receptor-mediated endocytosis (by, e.g., macrophages). By way of non-limiting example, toxR-invasin could be expressed on the surfaces of the minicells to promote endocytosis through the interaction between invasin and beta2-integrins on the surfaces of the target cells.[0772]
• Fusion proteins possessing viral fusion-promoting proteins facilitate entry of the minicell to the tumor cell for gene therapy or for delivery of chemotherapy bioactive proteins and nucleic acids. In these and similar applications, the minicell may contain separate eukaryotic and eubacterial expression elements, or the expression elements may be combined into a single “shuttle vector.”[0773]
• XV. Diagnostic Uses of Minicells[0774]
• Minicells are transformed with plasmids expressing membrane-bound proteins, such as receptors, that bind to specific molecules in a particular biological sample such as blood, urine, feces, sweat, saliva or a tissue such as liver or heart. Minicells can also be used for delivery of therapeutic agents across the blood-brain barrier to the brain. This modality is used, by way of non-limiting example, for imaging purposes, and for the delivery of therapeutic agents, e.g., anti-depressants, and agents for the treatment of cancer, obesity, insomnia, schizophrenia, compulsive disorders and the like. Recombinant expression systems are incorporated into minicells where the plasmid-driven protein expression construct could be the produce a single gene product or a fusion protein, such as a soluble protein for the particular ligand fused with a transmembrane domain of a different gene. The fusion protein then acts as a membrane bound receptor for a particular ligand or molecule in the sample. Conventional cloning techniques (e.g., PCR) are used to identify genes for binding proteins, or phage display is used to identify a gene for a single-stranded variable antibody gene expressing binding protein for a particular ligand. The protein product is preferably a soluble protein. By constructing a plasmid containing this gene plus the transmembrane domain of a known single-pass membrane protein such as that of the EGF receptor, a fusion protein may be expressed on the surfaces of the minicells as an integral membrane protein with an extracellular domain that is preferably capable of binding ligand.[0775]
• In another type of fusion protein, the transmembrane domain of the EGF receptor is fused to a known soluble receptor for a particular ligand, such as the LBP (lipopolysaccharide binding protein) or the extracellular domain of CD14 receptor protein, both of which bind the bacterial endotoxin, LPS (lipopolysaccharide). The LBP/EGF or CD14/EGF fusion protein is used to measure LPS in the serum of patients suspected of sepsis.[0776]
• The minicell system is used to express receptors such as those of the EDG (endothelial cell differentiation gene) family (e.g., EDG 1-9) that recognize sphingolipids such as sphingosine-1-phosphate (S1P), sphingosylphosphoryl choline (SPC) and the lysophospholipid, lysophosphatidic acid (LPA). Since these proteins are 7-pass integral membrane proteins, no additional transmembrane domains of another protein are needed, and the receptor protein is thus not a fusion protein.[0777]
• Truncated or mutant forms of a protein of interest are useful in a diagnostic assay. For example, a protein that is an ligand-binding enzyme can be altered so as to bind its substrate of interest but can no longer convert substrate into product. One example of this application of minicell technology is the expression of a truncated or mutant lactic dehydrogenase which is able to bind lactic acid, but is not able to convert lactic acid to pyruvate. Similarly, hexokinase deriviatives are used in minicells for glucose monitoring.[0778]
• Minicells as diagnostic tools can be used either in vitro or in vivo. In the in vitro context, the minicells are used in an ELISA format or in a lateral flow diagnostic platform to detect the presence and level of a desired analyte. A sample (tissue, cell or body fluid sample) is taken and then tested in vitro. One advantage of the minicell system in detecting substances in tissue, cells or in body fluids is that the minicells can be used in vitro assays where the minicell is labeled with either a radioactive or fluorescent compound to aid in its detection in a an ELISA format or lateral flow platform. Thus, the use of secondary antibody detection systems is obviated.[0779]
• As an in vivo diagnostic, minicells can be radiolabeled. One method of labeling is to incubate minicells for a short time (about 8 hr) with a T[0780]_1/2tracer (e.g., Tn99M) that is useful for detecting tumor metastases. The Tn99M accumulates in cells and loads into minicells after isolation or into the parent bacteria during growth phase. As Tn99M is oxidized by either the parentE. colistrain or by the minicells after isolation, the Tn99M is retained by the cell. Iodine-labled proteins may also be used (Krown et al., TNF-alpha receptor expression in rat cardiac myocytes: TNF-alpha inhibition of L-type Ca2+ transiets, FEBS Letters 376:24-30, 1995).
• One non-limiting example of in vivo detection of cancer making use of radiolabeled minicells is the use of the minicells to express chimeric membrane-bound single-chain antibodies against tumor-specific antigens (TSA) expressed on-malignant melanoma or other transformed cells. Such TSAs include, but are not limited to, the breast cancer associated MUC1 antigen and variant forms of the EGFR (EGFvIII). By way of non-limiting example, minicells expressing antibodies to melanoma cells can be injected (IV) into a patient and then subjected to CAT scan of the lymphatic drainage in order to determine if a metastasis has occurred. This diagnostic technique obviates the need for lymph node dissection.[0781]
• Another example of an in vivo diagnostic is to use the minicell system to express antibodies against oxidized low-density lipoproteins (LDL). Oxidized LDLs are associated with atherogenic plaques. Radiolabeled minicells (prepared as above) are injected IV into a person prior to nuclear imaging for image enhancement. MRI image contrast enhancement is performed by preparing minicells complexed (loaded) with contrast enhancers such as paramagnetic relaxivity agents and magnetic susceptibility agents.[0782]
• In diagnostic as well as other applications, minicells preferentially detect a diagnostic marker, i.e., a marker associated with a disease or disorder. A diagnostic marker is statistically more like to occur in individuals sufferening from a disease than in those who are not diseased. Preferably, a diagnostic marker directly causes or is produced during a disease; however, the association may be no more than a correlation.[0783]
• XVI. Drug Discovery (Screening) with Minicells[0784]
• XVI.A. Assays[0785]
• Minicells can be used in assays for screening pharmacological agents. By way of non-limiting example, the minicell system provides an environment for the expression of GPCRs and studies of their ligand binding kinetics. Such GPCR's include any member the Endothelial Differentiation Gene (EDG) receptor family. GPCRs may participate in neoplastic cell proliferation, angiogenesis and cell death. Small molecules that either activate or inhibit the action of these GPCRs can be used in therapeutic interaction.[0786]
• Assays are performed to determine protein expression and protein function. For example, the production of the protein can be followed using protein[0787]³⁵S-Met labeling. This is performed by providing the cell only methionine that is labeled with³⁵S. The cells are treated with IPTG to induce protein expression, and the³⁵S-Met is incorporated into the protein. The cells are then lysed, and the resulting lysates were electrophoresed on an SDS gel and exposed to autoradiography film.
• Another technique for assessing protein expression involves the use of western blots. Antibodies directed to various expressed proteins of interest have been generated and many are commercially available. Techniques for generating antibodies to proteins or polypeptides derived therefrom are known in the art (see, e.g., Cooper et al., Section III of Chapter 11 in: Short Protocols in Molecular Biology, 2nd Ed., Ausubel et al., eds., John Wiley and Sons, New York, 1992, pages 11-22 to 11-46). Standard western blot protocols, which may be used to show protein expression from the expression vectors in minicells and other expression systems, are known in the art. (see, e.g., Winston et al., Unit 10.7 of Chapter 10 in: Short Protocols in Molecular Biology, 2nd Ed., Ausubel et al., eds., John Wiley and Sons, New York, 1992, pages 10-32 to 10-35).[0788]
• The amount of functional protein produced from a minicell expression system is determined through the use of binding studies. Ligands for the proteins of interest are used to show specific binding in the minicell system. Radiolabeled ligand is incubated with cells expressing the protein, in this case, a receptor for TNF-alpha. The cells are then centrifuged and the radioactivity counted in a scintillation counter. The amount of ligand that is bound reflects the amount of functional protein that is present in the sample.[0789]
• By way of non-limiting example, the minicell system can be made to express EDGRs for the purpose of screening combinatorial chemistry libraries for molecules that enhance EDG activity. EDG activity is assayed in the minicell environment in several ways. One way is to crystallize minicells expressing an EDG protein (or any membrane-bound protein of choice) and then measure changes in the crystal structure to detect novel ligands. Circular dichroism (CD), x-ray diffraction, electron spin resonance (EPR) or other biophysical approaches are used to probe the structure of proteins in the minicell context. Additionally or alternately, minicells are produced that express not only the EDGR, but also express G-proteins (i.e., double transformants). An assay system involving GTP binding and hydrolysis is used to identify and assess which small molecules in the combinatorial chemistry library serve as activating ligands for EDG. The minicell expression system is used in in vitro binding assays and in high throughput drug screenings. The expression of mutant or truncated isoforms of proteins are used for functional analyses in order to discover inactive or overactive proteins for potential use in diagnostics or therapeutics.[0790]
• XVI.B. High-Throughput Screening (HTS)[0791]
• HTS typically uses automated assays to search through large numbers of compounds for a desired activity. Typically HTS assays are used to find new drugs by screening for chemicals that act on a particular enzyme or molecule. For example, if a chemical inactivates an enzyme it might prove to be effective in preventing a process in a cell that causes a disease. High throughput methods enable researchers to try out thousands of different chemicals against each target very quickly using robotic handling systems and automated analysis of results.[0792]
• As used herein, “high throughput screening” or “HTS” refers to the rapid in vitro screening of large numbers of compounds (libraries); generally tens to hundreds of thousands of compounds, using robotic screening assays. Ultra high-throughput Screening (uHTS) generally refers to the high-throughput screening accelerated to greater than 100,000 tests per day.[0793]
• To achieve high-throughput screening, it is best to house samples on a multicontainer carrier or platform. A multicontainer carrier facilitates measuring reactions of a plurality of candidate compounds simultaneously. Multi-well microplates may be used as the carrier. Such multi-well microplates, and methods for their use in numerous assays, are both known in the art and commercially available.[0794]
• Screening assays may include controls for purposes of calibration and confirmation of proper manipulation of the components of the assay. Blank wells that contain all of the reactants but no member of the chemical library are usually included. As another example, a known inhibitor (or activator) of an enzyme for which modulators are sought, can be incubated with one sample of the assay, and the resulting decrease (or increase) in the enzyme activity determined according to the methods herein. It will be appreciated that modulators can also be combined with the enzyme activators or inhibitors to find modulators which inhibit the enzyme activation or repression that is otherwise caused by the presence of the known the enzyme modulator. Similarly, when ligands to a sphingolipid target are sought, known ligands of the target can be present in control/calibration assay wells.[0795]
• The minicells of the invention are readily adaptable for use in high-throughput screening assays for screening candidate compounds to identify those which have a desired activity, e.g., inhibiting an enzyme that catalyzes a reaction that produces an undesirable compound, inhibiting function of a receptor independent of ligand interference, or blocking the binding of a ligand to a receptor therefor. The compounds thus identified can serve as conventional “lead compounds” or can themselves be used as therapeutic agents.[0796]
• The methods of screening of the invention comprise using screening assays to identify, from a library of diverse molecules, one or more compounds having a desired activity. A “screening assay” is a selective assay designed to identify, isolate, and/or determine the structure of, compounds within a collection that have a preselected activity. By “identifying” it is meant that a compound having a desirable activity is isolated, its chemical structure is determined (including without limitation determining the nucleotide and amino acid sequences of nucleic acids and polypeptides, respectively) the structure of and, additionally or alternatively, purifying compounds having the screened activity). Biochemical and biological assays are designed to test for activity in a broad range of systems ranging from protein-protein interactions, enzyme catalysis, small molecule-protein binding, agonists and antagonists, to cellular functions. Such assays include automated, semi-automated assays and HTS (high throughput screening) assays.[0797]
• In HTS methods, many discrete compounds are preferably tested in parallel by robotic, automatic or semi-automatic methods so that large numbers of test compounds are screened for a desired activity simultaneously or nearly simultaneously. It is possible to assay and screen up to about 6,000 to 20,000, and even up to about 100,000 to 1,000,000 different compounds a day using the integrated systems of the invention.[0798]
• Typically in HTS, target molecules are contained in each well of a multi-well microplate; in the case of enzymes, reactants are also present in the wells. Currently, the most widely established techniques utilize 96-well microtiter plates. In this format, 96 independent tests are performed simultaneously on a single 8 cm×12 cm plastic plate that contains 96 reaction wells. One or more blank wells contains all of the reactants except the candidate compound. Each of the non-standard wells contain at least one candidate compound.[0799]
• These wells typically require assay volumes that range from 50 to 500 ul. In addition to the plates, many instruments, materials, pipettors, robotics, plate washers and plate readers are commercially available to fit the 96-well format to a wide range of homogeneous and heterogeneous assays. Microtiter plates with more wells, such as 384-well microtiter plates, are also used, as are emerging methods such as the nanowell method described by Schullek et al. (Anal Biochem., 30 246, 20-29, 1997).[0800]
• In one modality, screening comprises contacting a sphingolipid target with a diverse library of member compounds, some of which are ligands of the target, under conditions where complexes between the target and ligands can form, and identifying which members of the libraries are present in such complexes. In another non limiting modality, screening comprises contacting a target enzyme with a diverse library of member compounds, some of which are inhibitors (or activators) of the target, under conditions where a product or a reactant of the reaction catalyzed by the enzyme produce a detectable signal. In the latter modality, inhibitors of target enzyme decrease the signal from a detectable product or increase a signal from a detectable reactant (or vice-versa for activators).[0801]
• Minicells of the invention expressing and/or displaying a protein are used for screening assays designed to identify agents that modulate the activity of the target protein. Such assays include competitive inhibition binding assays for high throughput assays. Competitive inhibition assays include but are not limited to assays that screen agents against a specific target protein to identify agents that inhibit, interfere, block, or compete with protein-ligand interactions, protein-protein interactions, enzymatic activity, or function of a specific protein. Examples of competitive inhibition include but are not limited to the development of neutral inhibitors of the serine protease factor Xa that were discovered using a high throughput screening assay using a compound library (Carr et al, Neutral inhibitors of the serine protease factor Xa, Bioorg Med Chem Lett 11, 2001), the design and characterization of potent inhibitors for the human oxytocin receptor (Seyer et al, Design, synthesis and pharmacological characterization of a potent radio iodinated and photoactivatable peptidic oxytocin antagonist, J Med Chem. 44:3022-30, 2001), and the identification of non-peptide somatostatin antagonists of the sst(3) protein (Thurieau et al, Identification of potent non-peptide somatostatin antagonists with sst(3) selectivity, J Med Chem. 44:2990-3000, 2001).[0802]
• High throughput competitive inhibition assays are designed to identify agents that inhibit a specific target protein. Such assays include but are not limited to ones that measure enzymatic activity, protein-ligand interactions, protein-protein interactions and other functions of proteins. Minicells that express and/or display a specific protein could be used in all types of competitive inhibition assays.[0803]
• One non-limiting example of high throughput competitive inhibition screening using minicells for the purpose of this patent involves the competitive inhibition of known ligands. The ligand is attached to but not limited to a flourophore, fluorescent protein, tags such as 6×His tag or FLAG tag, chromophores, radiolabeled proteins and molecules, binding moieties such as avidin and strepavidin, voltage sensitive dies and proteins, bioluminescent proteins and molecules, or fluorescent peptides. The target protein, which binds the tagged ligand, is expressed and stably displayed by the minicell. When the ligand is added to the minicell solution the ligand binds to the target protein. Following a wash the interaction is detected via the flourophore, fluorescent protein, tag, or fluorescent peptide. The ligand-bound minicells could either be centrifuged (taking advantage of the sedimentation properties of the minicell particle) or immunoprecipitated with an antibody against an antigen expressed on the minicell membrane or the minicells can be adsorbed/fixed to a substrate such as a standard 96 well plate. The competitive inhibition assay is carried out by adding agents to the minicell mix either before, together or after the ligand is added. Thus if the agent is a competitive inhibitor of the ligand to the target protein the ligand will be washed away from the minicell because it is not associated with the target protein. The agent prevents binding and thus eliminated the detection signal from the minicell.[0804]
• Minicells of this invention are used in “functional screening HTS assays”. Functional screening assays are defined as assays that provide information about the function of a specific target protein. Functional assays screen agents against specific target proteins to identify agents that either act as antagonist or as an agonist against the protein. Functional assays require that the target protein be in an environment that allows it to carry out its natural function. Such functions include but are not limited to G-proteins coupling with a GPCR, enzymatic activity such as phosphorlyation or proteolysis, protein-protein interaction, and transport of molecules and ions.[0805]
• Functional assays screen agents against proteins which are capable of natural function. Target proteins used in functional studies must carry out a function that is measurable. Examples of protein functions that are measurable include but are not limited to the use of Fluorescent Resonance Energy Transfer (FRET) to measure the G-protein coupling to a GPCR (Ruiz-Velasco et al., Functional expression and FRET analysis of green fluorescent proteins fused to G-protein subunits in rat sympathetic neurons, J Physiol. 537:679-692, 2001; Janetopoulos et al., Receptor-mediated activation of heterotrimeric G-proteins in living cells, Science 291:2408-2411, 2001); Bioluminescence Resonance Energy Transfer (BRET) to assay for functional ligand induced G-protein coupling to a target GPCR (Menard, L. Bioluminescence Resonance Energy Transfer (BRET): A powerful platform to study G-protein coupled receptors (GPCR) activity in intact cells, Assay Development, Nov. 28-30, 2001), the use of florescent substrates to measure the enzymatic activity of proteases (Grant, Designing biochemical assays for proteases using fluorogenic substrates, Assay Development, Nov. 28-30, 2001); and the determination of ion channel function via the use of voltage sensitive dies (Andrews et al, Correlated measurements of free and total intracellular calcium concentration in central nervous system neurons, Microsc Res Tech. 46:370-379, 1999).[0806]
• One non-limiting example of high throughput functional screening assay using minicells for the purpose of this patent involves the functional coupling of GPCRs to their respective G-protein. Upon ligand binding, voltage polarization, ion binding, light interaction and other stimulatory events activate GPCRs and cause them to couple to their respective G-protein. In a minicell, both the GPCR and its respective G-proteins can be simultaneously expressed. Upon activation of the GPCR the coupling event will occur in the minicell. Thus by detecting this coupling in the minicell, one could screen for agents that bind GPCRs to identify antagonists and agonists. The antagonists are identified using inhibition assays that detect the inhibition of function of the GPCR. Thus the agent interacts with the GPCR in a way that it inhibits the GPCR from being activated. The agonists are identified by screening for agents that activate the GPCR in the absence of the natural activator.[0807]
• The detection of GPCR activation and coupling in a minicell is accomplished by using systems that generate a signal upon coupling. One non-limiting example involves the use of BRET or FRET. These systems require that two fluorescent or bioluminescent molecules or proteins be brought into close contact. Thus by attaching one of these molecules or proteins to the GPCR and one to the G-protein, they will be brought together upon coupling and a signal will be generated. This signal can be detected using specific detection equipment and the coupling event can be monitored. Thus the function of the GPCR can be assayed and used in functional assays in minicells.[0808]
• Another non-limiting functional assay for GPCRs and other proteins in minicells involves the use of transcription factors. Many bacterial transcription factors and eukaryotic transcription factors require dimerization for activation. By attaching one subunit of a transcription factor to a GPCR and the other subunit to a G-protein, the subunits will dimerize upon coupling of the GPCR to the G-protein because they will be brought into close contact. The dimerized transcription factor will then be activated and will act on its target episomal DNA. In the minicell system the episomal DNA target will be a plasmid that encodes for proteins that provide a signal for detection. Such proteins include but are not limited to luciferase; green fluorescent protein (GFP), and derivatives thereof such as YFP, BFP, etc.; alcohol dehydrogenase, and other proteins that can be assayed for expression. The activation of the GPCR will result in coupling and activation of the transcription factor. The transcription factor will then induce transcription and translation of specific detector proteins. Thus the activation of the GPCR will be monitored via the expression of the detector protein.[0809]
• In another modality, the transcription factor can inhibit expression in the minicell system and thus allowing for the screening of constitutively active GPCRs and proteins. For example if the GPCR were constitutively active then the transcription factor to use would be one that inhibits transcription and translation. Thus agents could be screened against the constitutively active GPCR to identify agents that caused the constitutively active GPCR to uncouple. The uncoupling will result in the inactivation of the transcription factor. The inhibition caused by the transcription factor will be removed and transcription and translation will occur. Thus a detectable protein will be made and a signal will be received.[0810]
• The transcription dimerization assay can be used for any protein function that involves a protein-protein interaction, protein-ligand interaction and protein-drug interaction. Thus any assay involving such interactions can be carried out in the minicell.[0811]
• Another non-limiting functional screening assay involves the use of enzymatic function to screen for functionality. In this modality the receptor or other protein performs a specific enzymatic function. This function is then carried out in the minicell and monitored using biochemical and other techniques. For example if the target protein was a protease then fluorescent peptides with the cleavage site of the protease could be used to monitor the activity of the protease. If the protease was functioning then the peptide would be cleaved and the fluorescents would change. Thus agents can be screened against the protease in the minicell system and the fluorescents can be monitored using specific detection systems. In another non-limiting example, a membrane-bound enzyme such as sphingomyelinase could be expressed in minicells and the minicell particles adsorbed to a standard substrate such as a 96 well plate. The enzymatic activity could be assessed by a standard in vitro assay involving the release of product (phosphocholine) (e.g., AmplexTM kit A-12220 sold by Molecular Probes). Sphingomyelinase inhibitors could be screened by measuring the reduction of phosphocholine production in the well when presented with substrate (sphingomyelin) in a coupled fluorescence assay.[0812]
• Another non-limiting example of minicells used for functional assays involves the screening of agonists/antagonists for ion channels. In this example the calcium channel, SCaMPER, is encoded on a poycistronic episomal plasmid, which also encodes for a luminescent soluble protein, aequorin. In this assay, the minicell will contain aequorin proteins in its cytoplasm and SCaMPER proteins expressed on the minicell membrane. Thus upon activation of SCaMPER by its ligand, SPC, or by an analog thereof, calcium will flow into the minicell and will be bound by the aequorin which will luminescence. Thus a detection signal for the functional activation of the calcium channel is obtained.[0813]
• Minicell can also be employed for expression of target proteins and the preparation of membrane preparations for use in screening assays. Such proteins include but are not limited to receptors (e.g., GPCRs, sphingolipid receptors, neurotransmitter receptors, sensory receptors, growth factor receptors, hormone receptors, chemokine receptors, cytokine receptors, immunological receptors, and compliment receptors, FC receptors), channels (e.g., potassium channels, sodium channels, calcium channels.), pores (e.g., nuclear pore proteins, water channels), ion and other pumps (e.g., calcium pumps, proton pumps), exchangers (e.g., sodium/potassium exchangers, sodium/hydrogen exchangers, potassium/hydrogen exchangers), electron transport proteins (e.g., cytochrome oxidase), enzymes and kinases (e.g., protein kinases, ATPases, GTPases, phosphatases, proteases.), structural/linker proteins (e.g., Caveolins, clathrin), adapter proteins (e.g., TRAD, TRAP, FAN), chemotactic/adhesion proteins (e.g., ICAM11, selecting, CD34, VCAM-1, LFA-1,VLA-1), and chimeric/fusion proteins (e.g., proteins in which a normally soluble protein is attached to a transmembrane region of another protein). In such assays the membrane preparations are used to screen for agents that are either antagonists or agonists. These assays use various formats including but not limited to competitive inhibition.[0814]
• The format for the screening of minicells includes but is not limited to the use of test tubes, 6 well plates, 12 well plates, 24 well plates, 96 well plates, 384 well plates, 1536 well plates, and other microtiter well plates. In these systems the minicells can be immobilized, attached, bound, or fused with the above test tubes or plates. The minicells can also be free in solution for use in tubes and plates. The detection systems for the minicell assay include but are not limited to fluorescent plate readers, scintillation counters, spectrophotometers, Viewlux CCD Imager, Luminex, ALPHAQuest, BIAcore, FLIPR and F-MAT. Minicell assays can be carried out with but not limited to techniques such as manual handling, liquid handlers, robotic automated systems and other formats.[0815]
• XVI.C. Chemical Libraries[0816]
• Developments in combinatorial chemistry allow the rapid and economical synthesis of hundreds to thousands of discrete compounds. These compounds are typically arrayed in moderate-sized libraries of small organic molecules designed for efficient screening. Combinatorial methods, can be used to generate unbiased libraries suitable for the identification of novel inhibitors. In addition, smaller, less diverse libraries can be generated that are descended from a single parent compound with a previously determined biological activity. In either case, the lack of efficient screening systems to specifically target therapeutically relevant biological molecules produced by combinational chemistry such as inhibitors of important enzymes hampers the optimal use of these resources.[0817]
• A combinatorial chemical library is a collection of diverse chemical compounds generated by either chemical synthesis or biological synthesis, by combining a number of chemical “building blocks,” such as reagents. For example, a linear combinatorial chemical library, such as a polypeptide library, is formed by combining a set of chemical building blocks (amino acids) in a large number of combinations, and potentailly in every possible way, for a given compound length (i.e., the number of amino acids in a polypeptide compound). Millions of chemical compounds can be synthesized through such combinatorial mixing of chemical building blocks.[0818]
• A “library” may comprise from 2 to 50,000,000 diverse member compounds. Preferably, a library comprises at least 48 diverse compounds, preferably 96 or more diverse compounds, more preferably 384 or more diverse compounds, more preferably, 10,000 or more diverse compounds, preferably more than 100,000 diverse members and most preferably more than 1,000,000 diverse member compounds. By “diverse” it is meant that greater than 50% of the compounds in a library have chemical structures that are not identical to any other member of the library. Preferably, greater than 75% of the compounds in a library have chemical structures that are not identical to any other member of the collection, more preferably greater than 90% and most preferably greater than about 99%.[0819]
• The preparation of combinatorial chemical libraries is well known to those of skill in the art. For reviews, see Thompson et al., Synthesis and application of small molecule libraries, Chem Rev 96:555-600, 1996; Kenan et al., Exploring molecular diversity with combinatorial shape libraries, Trends Biochem Sci 19:57-64, 1994; Janda, Tagged versus untagged libraries: methods for the generation and screening of combinatorial chemical libraries, Proc Natl Acad Sci U S A. 91:10779-85, 1994; Lebl et al., One-bead-one-structure combinatorial libraries, Biopolymers 37:177-98, 1995; Eichler et al., Peptide, peptidomimetic, and organic synthetic combinatorial libraries, Med Res Rev. 15:481-96, 1995; Chabala, Solid-phase combinatorial chemistry and novel tagging methods for identifying leads, Curr Opin Biotechnol. 6:632-9, 1995; Dolle, Discovery of enzyme inhibitors through combinatorial chemistry, Mol Divers. 2:223-36, 1997; Fauchere et al., Peptide and nonpeptide lead discovery using robotically synthesized soluble libraries, Can J Physiol Pharmacol. 75:683-9, 1997; Eichler et al., Generation and utilization of synthetic combinatorial libraries, Mol Med Today 1:174-80, 1995; and Kay et al., Identification of enzyme inhibitors from phage-displayed combinatorial peptide libraries, Comb Chem High Throughput Screen 4:535-43, 2001.[0820]
• Such combinatorial chemical libraries include, but are not limited to, peptide libraries (see, e.g., U.S. Pat. No. 5,010,175, Furka, Int. J. Pept. Prot. Res., 37:487-493 (1991) and Houghton, et al., Nature, 354:84-88 1991). Other chemistries for generating chemical diversity libraries can also be used. Such chemistries include, but are not limited to, peptoids (PCT Publication No. WO 91/19735); encoded peptides (PCT Publication WO 93/20242); random bio-oligomers (PCT Publication No. WO 92/00091); benzodiazepines (U.S. Pat. No. 5,288,514); diversomers, such as hydantoins, benzodiazepines and dipeptides (Hobbs, et al., Proc. Nat. Acad. Sci. USA, 90:6909-6913 1993); vinylogous polypeptides (Hagihara, et al., J. Amer. Chem. Soc. 114:6568 1992); nonpeptidal peptidomimetics with .beta.-D-glucose scaffolding (Hirschmann, et al., J. Amer. Chem. Soc., 114:9217-9218 1992); analogous organic syntheses of small compound libraries (Chen, et al., J. Amer. Chem. Soc., 116:2661 1994); oligocarbamates (Cho, et al., Science, 261:1303 1993); and/or peptidyl phosphonates (Campbell, et al., J. Org. Chem. 59:658 1994); nucleic acid libraries (see, Ausubel, Berger and Sambrook, all supra); peptide nucleic acid libraries (see, e.g., U.S. Pat. No. 5,539,083); antibody libraries (see, e.g., Vaughn, et al., Nature Biotechnology, 14(3):309-314 (1996) and PCT/US96/10287); carbohydrate libraries (see, e.g., Liang, et al., Science, 274:1520-1522 (1996) and U.S. Pat. No. 5,593,853); small organic molecule libraries (see, e.g., benzodiazepines, Baum C&E News, Jan. 18, page 33 (1993); isoprenoids (U.S. Pat. No. 5,569,588); thiazolidinones and metathiazanones (U.S. Pat. No. 5,549,974); pyrrolidines (U.S. Pat. Nos. 5,525,735 and 5,519,134); morpholino compounds (U.S. Pat. No. 5,506,337); benzodiazepines (U.S. Pat. No. 5,288,514); and the like.[0821]
• Devices for the preparation of combinatorial libraries are commercially available (see, e.g., 357 MPS, 390 MPS, Advanced Chem. Tech, Louisville Ky., Symphony, Rainin, Woburn, Mass., 433A Applied Biosystems, Foster City, Calif., 9050 Plus, Millipore, Bedford, Mass.). In addition, numerous combinatorial libraries are themselves commercially available (see, e.g., ComGenex, Princeton, N.J., Asinex, Moscow, Ru, Tripos, Inc., St. Louis, Mo., ChemStar, Ltd., Moscow, RU, 3D Pharmaceuticals, Exton, Pa., Martek Bio sciences, Columbia, Md., etc.).[0822]
• XVI.D. Measuring Enzymatic and Binding Reactions During Screening Assays[0823]
• Techniques for measuring the progression of enzymatic and binding reactions in multicontainer carriers are known in the art and include, but are not limited to, the following.[0824]
• Spectrophotometric and spectrofluorometric assays are well known in the art. Examples of such assays include the use of colorimetric assays for the detection of peroxides, as disclosed in Example 1(b) and Gordon, A. J. and Ford, R. A.,[0825]The Chemist's Companion: A Handbook Of Practical Data, Techniques, And References,John Wiley and Sons, N.Y., 1972, Page 437.
• Fluorescence spectrometry may be used to monitor the generation of reaction products. Fluorescence methodology is generally more sensitive than the absorption methodology. The use of fluorescent probes is well known to those skilled in the art. For reviews, see Bashford et al.,[0826]Spectrophotometry and Spectrofluorometry: A Practical Approach,pp. 91-114, IRL Press Ltd. (1987); and Bell,Spectroscopy In Biochemistry,Vol. 1, pp. 155-194, CRC Press (1981).
• In spectrofluorometric methods, enzymes are exposed to substrates that change their intrinsic fluorescence when processed by the target enzyme. Typically, the substrate is nonfluorescent and converted to a fluorophore through one or more reactions. As a non-limiting example, SMase activity can be detected using the Amplex® Red reagent (Molecular Probes, Eugene, Oreg.). In order to measure sphingomyelinase activity using Amplex Red, the following reactions occur. First, SMase hydrolyzes sphingomyelin to yield ceramide and phosphorylcholine. Second, alkaline phosphatase hydrolyzes phosphorylcholine to yield choline. Third, choline is oxidized by choline oxidase to betaine. Finally, H[0827]₂O₂, in the presence of horseradish peroxidase, reacts with Amplex Red to produce the fluorescent product, Resorufin, and the signal therefrom is detected using spectrofluorometry.
• Fluorescence polarization (FP) is based on a decrease in the speed of molecular rotation of a fluorophore that occurs upon binding to a larger molecule, such as a receptor protein, allowing for polarized fluorescent emission by the bound ligand. FP is empirically determined by measuring the vertical and horizontal components of fluorophore emission following excitation with plane polarized light. Polarized emission is increased when the molecular rotation of a fluorophore is reduced. A fluorophore produces a larger polarized signal when it is bound to a larger molecule (i.e. a receptor), slowing molecular rotation of the fluorophore. The magnitude of the polarized signal relates quantitatively to the extent of fluorescent ligand binding. Accordingly, polarization of the “bound” signal depends on maintenance of high affinity binding.[0828]
• FP is a homogeneous technology and reactions are very rapid, taking seconds to minutes to reach equilibrium. The reagents are stable, and large batches may be prepared, resulting in high reproducibility. Because of these properties, FP has proven to be highly automatable, often performed with a single incubation with a single, premixed, tracer-receptor reagent. For a eview, see Owickiet al., Application of Fluorescence Polarization Assays in High-Throughput Screening, Genetic Engineering News, 17:27, 1997.[0829]
• FP is particularly desirable since its readout is independent of the emission intensity (Checovich, W. J., et al., Nature 375:254-256, 1995; Dandliker, W. B., et al., Methods in Enzymology 74:3-28, 1981) and is thus insensitive to the presence of colored compounds that quench fluorescence emission. FP and FRET (see below) are well-suited for identifying compounds that block interactions between receptors and their ligands. See, for example, Parker et al., Development of high throughput screening assays using fluorescence polarization: nuclear receptor-ligand-binding and kinase/phosphatase assays, J Biomol Screen 5:77-88, 2000.[0830]
• Exemplary normal-and-polarized fluorescence readers include the POLARION fluorescence polarization system (Tecan A G, Hombrechtikon, Switzerland). General multiwell plate readers for other assays are available, such as the VERSAMAX reader and the SPECTRAMAX multiwell plate spectrophotometer (both from Molecular Devices).[0831]
• Fluorescence resonance energy transfer (FRET) is another useful assay for detecting interaction and has been described previously. See, e.g., Heim et al., Curr. Biol. 6:178-182, 1996; Mitra et al., Gene 173:13-17 1996; and Selvin et al., Meth. Enzymol. 246:300-345, 1995. FRET detects the transfer of energy between two fluorescent substances in close proximity, having known excitation and emission wavelengths. As an example, a protein can be expressed as a fusion protein with green fluorescent protein (GFP). When two fluorescent proteins are in proximity, such as when a protein specifically interacts with a target molecule, the resonance energy can be transferred from one excited molecule to the other. As a result, the emission spectrum of the sample shifts, which can be measured by a fluorometer, such as a fMAX multiwell fluorometer (Molecular Devices, Sunnyvale Calif.).[0832]
• Scintillation proximity assay (SPA) is a particularly useful assay for detecting an interaction with the target molecule. SPA is widely used in the pharmaceutical industry and has been described (Hanselman et al., J. Lipid Res. 38:2365-2373 (1997); Kahl et al., Anal. Biochem. 243:282-283 (1996); Undenfriend et al., Anal. Biochem. 161:494-500 (1987)). See also U.S. Pat. Nos. 4,626,513 and 4,568,649, and European Patent No. 0,154,734. An exemplary commercially available system uses FLASHPLATE scintillant-coated plates (NEN Life Science Products, Boston, Mass.).[0833]
• The target molecule can be bound to the scintillator plates by a variety of well known means. Scintillant plates are available that are derivatized to bind to fusion proteins such as GST, His6 or Flag fusion proteins. Where the target molecule is a protein complex or a multimer, one protein or subunit can be attached to the plate first, then the other components of the complex added later under binding conditions, resulting in a bound complex.[0834]
• In a typical SPA assay, the gene products in the expression pool will have been radiolabeled and added to the wells, and allowed to interact with the solid phase, which is the immobilized target molecule and scintillant coating in the wells. The assay can be measured immediately or allowed to reach equilibrium. Either way, when a radiolabel becomes sufficiently close to the scintillant coating, it produces a signal detectable by a device such as a TOPCOUNT NXT microplate scintillation counter (Packard BioScience Co., Meriden Conn.). If a radiolabeled expression product binds to the target molecule, the radiolabel remains in proximity to the scintillant long enough to produce a detectable signal.[0835]
• In contrast, the labeled proteins that do not bind to the target molecule, or bind only briefly, will not remain near the scintillant long enough to produce a signal above background. Any time spent near the scintillant caused by random Brownian motion will also not result in a significant amount of signal. Likewise, residual unincorporated radiolabel used during the expression step may be present, but will not generate significant signal because it will be in solution rather than interacting with the target molecule. These non-binding interactions will therefore cause a certain level of background signal that can be mathematically removed. If too many signals are obtained, salt or other modifiers can be added directly to the assay plates until the desired specificity is obtained (Nichols et al., Anal. Biochem. 257:112-119, 1998).[0836]
• XVI.E. Screening for Novel Antibiotics[0837]
• As bacteria and other pathogens acquire resistance to known antibiotics, there is an ongoing interest in identifying novel antibiotics. See, e.g., Powell W A, Catranis C M, Maynard C A. Synthetic antimicrobial peptide design. Mol Plant Microbe Interact September-October 1995;8(5):792-4. Minicells can be used to assay, identify and purify novel antibiotics to eubacteria. By way of non-limiting example, a minicell that comprises a detectable compound can be contacted with a candidate antibiotic to see if the minicell is lysed by a candidate compound, which would release the detectable compound from the interior of the minicell into solution, this producing a signal that indicates that the candidate antibiotic is effective at lysing bacteria. In such assays, the detectable compound is such that it produces less or more of the same signal, or a different signal, inside the minicell as compared to in solution post-lysis. By way of non-limiting example, the minicell could comprise a fluorescent compounds that, when contacted with a second fluorescent compound in solution, produces FRET.[0838]
• XVI. F. Reverse Screening[0839]
• In one version of minicell display, the invention provides methods for screening libraries of minicells in which each minicell comprises an expression element that encodes a few, preferably one, membrane proteins in order to identify a membrane protein that interacts with a preselected compound. By way of non-limiting example, sequences encoding membrane proteins, fusion proteins, or cytoplasmic proteins are cloned into an expression vector, either by “shotgun” cloning or by directed cloning, e.g., by screening or selecting for cDNA clones, or by PCR amplification of DNA fragments, that encode a protein using one or more oligonucleotides encoding a highly conserved region of a protein family. For a non-limiting example of such techniques, see Krautwurst, D., et al. 1998. Identification of ligands for olfactory receptors by functional expression of a receptor library. Cell 95:917-926. By way of non-limiting example, a minicell expressing a receptor binds a preselected ligand, which may be a drug. Various assays for receptor binding, enzymatic activity, and channeling events are known in the art and may include detectable compounds; in the case of binding assays, competition assays may also be used (Masimirembwa, C. M., et al. 2001. In vitro high throughput screening of compounds for favorable metabolic properties in drug discovery. Comb. Chem. High Throughput Screen. 4:245-263; Mattheakis, L. C., and A. Saychenko. 2001. Assay technologies for screening ion channel targets. Curr. Opin. Drug Discov. Devel. 4:124-134; Numann, R., and P. A. Negulescu. 2001. High-throughput screening strategies for cardiac ion channels. Trends Cardiovasc. Med. 11:54-59; Le Poul, E., et al. 2002. Adaptation of aequorin functional assay to high throughput screening. J. Biomol. Screen. 7:57-65; and Graham, D. L., et al. 2001. Application of beta-galactosidase enzyme complementation technology as a high throughput screening format for antagonists of the epidermal growth factor receptor. J. Biomol. Screen. 6:401-411).[0840]
• Once a minicell has been identified by an assay and isolated, DNA is prepared from the minicell. The cloned DNA present in the minicell encodes the receptor displayed by the minicell. Having been cloned, the receptor is used as a therapeutic target. For example, the receptor is produced via recombinant DNA expression and used in minicell-based or other assays to identify and characterize known and novel compounds that are ligands, antagonists and/or agonists of the cloned receptor. The ligands, antagonists and agonists may be used as lead compounds and/or drugs to treat diseases in which the receptor plays a role. In particular, when the preselected ligand is a drug, diseases for which that drug is therapeutic are expected to be treated using the novel ligands, antagonists and agonists, or drugs and prodrugs developed therefrom.[0841]
• Preparations of minicells that express and secrete secretes a soluble protein can be prepared in order to identify ligands, including but not limited to small molecules, that interact with the soluble protein. Soluble proteins include, but are not limited to, known secreted or proteolytically cleaved proteins and peptides, hormones and cytokines. In this format, minicells are placed in, or adhered to, the wells of a microtiter multiwell plate. A different compound or group of compounds is placed in each well, along with any reagents necessary to generate or squelch a signal corresponding to a change in the soluble protein produced by the minicell. Such changes include, by way of non-limiting example, conformational changes in the protein that may occur as a result of binding of a ligand or otherwise. A well that generates the appropriate signal contains a compound that causes a change in the soluble protein.[0842]
• It is also possible to carry out procedures such as the one described in the immediately preceding paragraph “in reverse.” In this format, a known ligand, which may be a drug, is used to identify soluble proteins that bind to the ligand/drug. Libraries of minicells wherein each minicell secretes a different soluble protein are prepared, and each type of minicell is placed into, or adhered to the wall of, a well of a microtiter plate, along with reagents for generating a signal when the ligand/drug binds to a soluble protein. Minicells that generate the appropriate signal comprise a cloned DNA that encodes a soluble protein that interacts with the known ligand/drug. Once cloned, the soluble protein is prepared and used as a therapeutic target in order to identify known or novel compounds that bind thereto. When the preselected ligand is a drug, diseases for which that drug is therapeutic are expected to be treated using the known and novel compounds so identified, or using drugs and prodrugs developed from such compounds.[0843]
• Mincells expressing known membrane and soluble proteins can also be used to help characterize lead compounds and accelerate the generation of drugs therefrom. In particular, such studies may be used identify potentially detrimental interactions that might occur upon in vivo administration, e.g., ADME/Tox screening (Ekins, S., et al. 2002. In silico ADME/Tox: the state of the art. J. Mol. Graph. Model. 20:305-309; and Li, A., et al. 2002. Early ADME/Tox studies and in silico screening. Drug Discov. Today 7:25-27).[0844]
• By way of non-limiting example, a human receptor that is known to be important for the normal functioning of a cell may be expressed in mincells, and various chemical derivatives of a lead compound can be tested to ensure that they do not bind to the receptor, as such binding would be expected to have adverse effects in vivo. As another example, an enzyme that degrades a drug, such as a cytochrome P450, is expressed in mincells and used to examine the susceptibility of a candidate drug to such degradation. The cytochrome P450 family of enzymes is primarily responsible for the metabolism of xenobiotics such as drugs, carcinogens and environmental chemicals, as well as several classes of endobiotics such as steroids and prostaglandins. Exemplary P450 cytochromes involved in drug degradation include, but are not limited to, CYP2D6 (cytochrome P4502D6, also known as debrisoquine hydroxylase), CYP1A1, CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5.[0845]
• XVI. G. Molecular Variants[0846]
• In one aspect of the invention, minicells are used in methods of screening to identify agents that improve, enhance, or decrease the interaction of a protein with another compound. These methods include, by way of non-limiting example, modification of protein targets through directed or random mutagenic approaches to identify critical interactions between a wild-type protein target and a specific drug molecule. Information obtained from studies of mutant proteins is used to specifically produce or modify a therapeutic agent to interact more specifically and/or effectively with the wild-type protein target, thus increasing the therapeutic efficacy of the parental drug and/or decreasing non-specific, potentially deleterious interactions. See, for example, Lietha, D., et al. 2001. Crystal structures of NK1-heparin complexes reveal the basis for NK1 activity and enable engineering of potent agonists of the MET receptor. EMBO J. 20:5543-5555; and Chen, Y. Z., et al. Can an optinization/scoring procedure in ligand-protein docking be employed to probe drug-resistant mutations in proteins? J. Mol. Graph. Model. 19:560-570;Zhao, H. and F. H. Arnold. Combinatorial protein design: Strategies for screening protein libraries. Current Opinion in Structural Biology 7:480-485 (1997); and Carrupt P A, el Tayar N, Karlen A, Testa B. Molecular electrostatic potentials for characterizing drug-biosystem interactions. Methods Enzymol. 1991;203:638-77. Martin Y C. Computer-assisted rational drug design. Methods Enzymol. 1991;203:587-613.[0847]
• By way of non-limiting example, information obtained using the methods of the invention may be in conjunction with x-ray crystallographic structural determinations to characterize receptor:ligand interactions (Muller, G. 2000. Towards 3D structures of G protein-coupled receptors: a multidisciplinary approach. Curr. Med. Chem. 7:861-888). By way of non-limiting example, minicells may be used to display the family of molecular variants to characterize the specific mutagenic changes on the functional properties of the protein.[0848]
• Studies of variant proteins can also be used to modify drugs to fit natural variants of proteins, especially those associated with pathogens. Pathogens such as viruses, including retroviruses such as HIV, may acquire mutations that change a site where a drug acts, thereby rendering the pathogen immune to the drug. Studies of variant proteins can be used to quickly produce derivatives of a drug that are active against a variant protein. See, for example, Varghese J N, Smith P W, Sollis S L, Blick T J, Sahasrabudhe A, McKimm-Breschkin J L, Colman P M. Drug design against a shifting target: a structural basis for resistance to inhibitors in a variant of influenza virus neuraminidase. Structure Jun. 15, 1998;6(6):735-46; and Baldwin E T, Bhat T N, Liu B, Pattabiraman N, Erickson J W. Structural basis of drug resistance for the V82A mutant of HIV-1 proteinase. 78: Nat Struct Biol March 1995;2(3):244-9.[0849]
• XVI.H. Directed Evolution[0850]
• The minicells and methods described herein can be used in directed evolution. Unlike natural variation, directed evolution generates new protein variants in vitro (see, e.g., Arnold, F. H. and A. A. Violkov. Directed Evolution of Biocatalysts. Curr Op Chem Biol 1999. 3:54-59). Amino acid substitutions can be introduced into a protein of interest by mutating the gene encoding the protein. Mutations are introduced by, e.g., replicating DNA in mutator strains, by chemical mutagenesis or radiation-induced mutagenesis (Drake, J. W., The Molecular Basis of Mutation, Holden-Day, San Francisco, 1970). Other methods include error-prone PCR and “domain shuffling” (Moore, G. L. and C. D. Maranas. Modeling DNA Mutation and Recombination for Directed Evolution Experiments. J. Ther. Biol. 2000.205:483-503). In the latter method, different regions of members of the same gene family are recombined so that the inherent variability of members of the family is used to produce novel “isoforms” of genes.[0851]
• A group of variants is screened to select for those variants which have the desired activity. The activity of the initial variants that are so isolated may be inadequate for a given application, but the process can be repeated using these initial members to generate a second group of variants, or reiterated as many times as is necessary to produce one or more variants having the desired activity or characteristics.[0852]
• XVI.I. Isolation and Characterization of Components of Signal Tranduction Pathways[0853]
• In one version of minicell display, the invention provides methods for screening libraries of minicells, in which each minicell comprises a preselected component of a signal transduction pathway, in order to identify soluble and membrane proteins that interact with the preselected component. By way of non-limiting example, a plurality of minicells, each of which displays the same G-protein-coupled receptor (GPCR), is used to prepare a minicell library in which a different G-protein encoding sequence is present and expressed in each minicell. Minicells comprising a G-protein that interacts with the GPCR are identified, e.g., via transactivation assays described in Example 18. Once a minicell has been identified by an assay and isolated, DNA is prepared from the minicell. The cloned DNA present in the minicell encodes a G-protein that interacts with the GPCR of the dsiplayed by the minicells of the library. Having been cloned, the G-protein is used as a therapeutic target that can be used in screening assays to identify novel lead compounds and drugs that interfere or alter the activity of the GPCR. In particular, when the GPCR of the minicell library is known to be a therapeutic target for a specific disease, it is expected that compounds that interfere or alter the activity of a G-protein that interacts with the GPCR will be or lead to therapeutics for that specific disease.[0854]
• In addition to G-protein signal transduction pathways, other non-limiting examples of signal tranduction pathways include the MAPK pathway, the SAPK pathway, the p38 pathway and/or the ceramide-mediated stress response pathway. See Zhang, W., and L. E. Samelson. 2000. The role of membrane-associated adaptors in T cell receptor signalling. Semin. Immunol. 12:35-41; Liebmann, C. 2001. Regulation of MAP kinase activity by peptide receptor signalling pathway: paradigms of multiplicity. Cell Signal. 13:777-785; Lee, Jr., J. T., and J. A. McCubrey. 2002. The Raf/MEK/ERK signal transduction cascade as a target for chemotherapeutic intervention in leukemia. Leukemia. 16:486-507; Tibbles, L. A., and J. R. Woodgett. 1999. The stress-activated protein kinase pathways. Cell Mol. Life Sci. 55:1230-1254; Rao, K. M. 2001. MAP kinase activation of macrophages. J. Leukoc. Biol. 69:3-10; Pelech, S. L., and D. L. Charest. 1995. MAP kinase-dependent pathways in cell cycle control. Prog. Cell Cycle Res. 1:33-52; Lee, S. H., et al. 2001. BetaPix-enhanced p38 activation by Cdc42/Rac/PAK/MKK3/6-mediated pathway. Implication in the regulation of membrane ruffling. J. Biol. Chem. 276:25066-25072; Ono, K., et al. 2000. The p38 signal transduction pathway Activation and function. Cellular Signalling 12:1-13; You, A. 2001. Differentiation, apoptosis, and function of human immature and mature myeloid cells: intracellular signaling mechanism. Int. J. Hematol. 73:438-452; Johnson, D. I. 1999. Cdc42: An essential Rho-type GTPase controlling eukaryotic cell polarity. Microbiol. Mol. Biol. Rev. 63:54-105; Williams, J. A. 2001. Intracellular signaling mechanisms activated by cholecystokinin-regulating synthesis and secretion of digestive enzymes in pancreatic acinar cells. Annu. Rev. Physiol. 63:77-97; Mathias, S., et al. 1998. Signal trasduction of stress via ceramide. Biocehm J. 335:465-480; and Hannun, Y. A., et al. 2000. Ceramide in the eukaryotic stress response. Trends Cell Biol. 10:73-80.[0855]
• XVII. Determining the Structures of Membrane Proteins[0856]
• Three-dimensional (3D) structures of proteins may be used for drug discovery. However, GPCRs and other membrane proteins present challenging problems for 3D structure determination. Muller, Towards 3D structures of G protein-coupled receptors: a multidisciplinary approach. (Review), Curr Med Chem 2000 pp.861-88; Levy et al., Two-dimensional crystallization on lipid layer: A successful approach for membrane proteins, J Struct Biol 1999 127, 44-52. Although the three-dimensional structures of hundreds of different folds of globular proteins have been determined, fewer than 20 different integral membrane protein structures have been determined. There are many reasons for this. Extracting membrane proteins from the membrane can easily disrupt their native structure, and membrane proteins are notoriously difficult to crystallize.[0857]
• Some membrane proteins readily form two-dimensional crystals in membranes and can be used for structure determination using electron diffraction spectroscopy (ED) instead of x-ray crystallography. This is the technique that was used to determine the structure of bacteriorhodopsin (see below).[0858]
• Nuclear magnetic resonance (NMR) is an alternative method for determining membrane protein structure, but most membrane proteins are too large for high-resolution NMR at the present state of the art. Furthermore, membrane proteins require special conditions for NMR, e.g. deuterated lipids must be used to avoid confusing the signal of the protein protons with the noise of membrane lipid protons.[0859]
• Membrane protein for which structures have been determined include photosynthetic reaction center, porin, porin OmpF, plant light-harvesting complex (chlorophyll a-b binding protein), bacterial light-harvesting complex, cytochrome c oxidase, glycophorin A, the Sec A translocation ATPase of[0860]Bacillus subtilis,and a bacterial potassium channel. For details, see: Weinkauf et al., (2001): Conformational stabilization and crystallization of the Sec A translocation ATPase fromBacillus subtilis.Acta Crystallogr D Biol Crystallogr 57:559-565; Cowan et al., (1992): Crystal structures explain functional properties of twoE. coliporins. Nature 358:727-33; Deisenhofer et al., (1984): X-ray structure analysis of a membrane protein complex. Electron density map at 3 A resolution and a model of the chromophores of the photosynthetic reaction center fromRhodopseudomonas viridis.J Mol Biol 180:385-98; Deisenhofer et al., (1985): Structure of the protein subunits in the photosynthetic reaction centre ofRhodopseudomonas viridisat 3 Angstroms resolution. Nature 318:618; Doyle et al., (1998): The structure of the potassium channel: molecular basis of K+ conduction and selectivity. Science 280:69-77; Henderson et al., (1990): Model for the structure of bacteriorhodopsin based on high-resolution electron cryo-microscopy. J Mol Biol 213:899-929; Iwata et al., (1998): Complete structure of the 11-subunit bovine mitochondrial cytochrome bcl complex. Science 281:64-71; Koepke et al., (1996): The crystal structure of the light-harvesting complex II (B800-850) fromRhodospirillum molischianum.Structure 4:581-97; Kuhlbrandt et al., (1994): Atomic model of plant light-harvesting complex by electron crystallography. Nature 367:614-21; Lemmon et al., (1992): Sequence specificity in the dimerization of transmembrane alpha-helices. Biochemistry 31:12719-25; MacKenzie et al., (1997): A transmembrane helix dimer: structure and implications. Science 276:131-3; McDermott et al., (1995): Crystal structure of an integral membrane light-harvesting complex from photosynthetic bacteria, Nature 374:517-21; Michel (1982): Three-dimensional crystals of a membrane protein complex. The photosynthetic reaction centre fromRhodopseudomonas viridis.J Mol Biol 158:567-72; Tsukihara et al., (1996): The whole structure of the 13-subunit oxidized cytochrome c oxidase at 2.8 A. Science 272:1136-44; and Weiss et al., (1991): The structure of porin from Rhodobacter capsulatus at 1.8 A resolution. FEBS Lett 280:379-82. Table 5, which is based upon Preusch et al. (1998) as revised by White & Wimley (1999), lists membrane proteins whose crystallographic structures have been determined.

  TABLE 5
  Structural Data Regarding Membrane Proteins

  PROTEIN	REFERENCES
  MONOTOPIC MEMBRANE PROTEINS
  Portaglandin H2 synthase-1. Sheep. 3.5 Å	Picot et al. (1994)
  Cyclooxygenase-2. Mus Musculus. 3.0 Å	Kurumbail et al. (1996)
  Squalene-hopene cyclase. Alicyclobacillus acidocaldarius.	Wendt et al. (1999)
  2.0 Å
  TRANSMEMBRANE PROTEINS
  Bacterial Rhodopsins
  (Halobacterium salinarium)
  Bacteriorhodopsin (BR)
  2D xtals. EM. 3.5 Å	Grigrorieff et al. (1996)
  2D xtals. EM. 3.0 Å	Kimura et al. (1997)
  3D xtals. X-ray. 2.5 Å	Pebay-Peyroula et al. (1997)
  3D xtals. X-ray. 1.9 Å	Belhrhali et al. (1999)
  3D xtals. X-ray 2.1 Å K intermediate	Edman et al. (1999)
  3D xtals. X-ray. 2.3 Å	Luecke et al. (1998)
  3D xtals. X-ray. 1.55 Å	Luecke et al. (1999)
  3D xtals. X-ray. D96N mutant (BR) 1.80 Å.	Luecke et al. (1999)
  3D xtals. X-ray. D96N mutant (M) 2.00 Å
  3D xtals. X-ray. 2.9 Å	Essen et al. (1998)
  Halorhodopsin (HR)
  3D xtals. X-ray. 1.8 Å	Kolbe et al. (2000)
  G PROTEIN-COUPLED RECEPTORS
  Rhodopsin. Bovine Rod Outer Segment. 2.8 Å	Palczewski et al. (2000)
  Photosynthetic Reaction Centers
  Rhodopseudomonas virdis. 2.3 Å	Deisenhofer et al. (1985)
  Rhodobacter sphaeroides. 3.0 Å	Yeates et al. (1987)
  Rhodobacter sphaeroides. 3.1 Å	Chang et al. (1991)
  Light Harvesting Complexes
  Rhodopseudomonas acidophila. 2.5 Å	McDermott et al. (1995)
  Rhodospirillum molischianum. 2.4 Å	Koepke et al. (1996)
  Photosystems
  Photosystem I. Synechococcus elongates 4.0 Å	Schubert et al. (1997)
  Photosystem II. Synechocoocus elongates 3.8 Å	Zouni et al. (2001)
  Beta-Barrel Membrane Proteins-Multimeric (Porins and
  Relatives)
  Porin. Rhodobacter capsulatus. 1.8 Å	Weiss & Schulz (1992)
  Porin. Rhodopeudomonas blastica 1.96 Å	Kreutsch et al. (1994)
  OmpF.E. coli.2.4 Å	Cowan et al. (1992)
  PhoE.E. coli.3.0 Å	Cowan et al. (1992)
  Maltoporin. Salmonella typhimurium. 2.4 Å	Meyer et al. (1997)
  Maltoporin. E. coli 3.1 Å	Schirmer et al. (1995)
  Beta-Barrel Membrane Proteins-Monomeric/Dimeric
  TolC outer membrane protein.E. coli2.1 Å Protein is a	Koronakis et al. (2000)
  trimer, each contributing 4 strands to a single barrel.
  OmpAE. coli.2.5 Å	Pautsch & Schulz (1998)
  OmpAE. coli.By NMR, in DPC micelles	Arora et al. (2001)
  OmpX.E. coli.1.9 Å	Vogt & Schulz (1990)
  OMPLA (outer membrane phospholipase A) E. coli. 2.1 Å.	Snijder et al. (1999)
  monomer (1QD5) and dimer (1QD6)
  FhuA.E. coli.2.5 Å	Ferguson et al. (1998); Lambert et al., 1999
  FhuA + ferrichrome-iron.E. coli.2.7 Å	Buchanan et al. (1999)
  FepA. E. coli. 2.4 Å	Ferguson et al. (1999)
  Glycophorin A. humanm.	MacKenzie et al. (1997)
  Non-constitutive Toxins, etc.
  Alpha-hemolysin. Staphylococcus aureus. 1.9 Å	Song et al. (1996)
  LukF. Staphylococcus aureus. 1.9 Å	Olson et al. (1999)
  Ion Channels
  KcsA Potassium, H+gated. Streptomyces lividans. 3.2 Å	Doyle et al. (1998)
  MscL Mechanosensitive. Mycobacterium tuberculosis.	Chang et al. (1998)
  3.5 Å
  Other Channels
  AQP1 - aquaporin water channel. Red blood cell.	Murata et al. (2000)
  Electron crystallography in membrane plane. 3. 8 Å
  AQP1 - In vitreous ice by electron microscopy. 3.7 Å	Ren et al. (2000)
  GipF - glycerol facilitator channel. E. coli. 2.2 Å	Fu et al. (2000)
  P-type ATPase
  Calcium ATPase. Sarcoplasmic reticulum. Rabbit. 2.6 Å	Toyoshima et al. (2000)
  Respiratory Proteins
  Fumerate Reductase Complex. Escherichia coli. 3.3 Å	Iverson et al. (1999)
  Fumerate Reductase Complex. Wolinella succinogenes	Lancaster et al. (1999)
  2.2 Å
  ATP synthase (F1C10). S. cerevisiae. 3.9 Å. X-ray	Stock et al. (1999)
  structure is a C alpha model derived from composite of
  1BMF, 1A91 & 1AQT
  Cytochrome C Oxidases
  aa3 bovine heart mitochondria. 2.8 Å	Tsukihara et al. (1996)
  aa3 Paracoccus denitrificans. 2.8 Å	Iwata et al. (1995)
  ba3 from T. thermophilus. 2.4 Å	Soulimane et al. (2000)
  Cytochrome bc1 Complexes
  Bovine Heart Mitochondria (5 subunits). 2.9 Å	Xia et al. (1997)
  Chicken Heart Mitochondria. 3.16 Å	Zhang et al. (1998)
  Bovine Heart Mitochondria (11 subunits). 2.8-3.0 Å.	Iwata et al. (1998)
  S. cerevisiae(yeast, 9 subunits). 2.3 Å	Hunte et al. (2000)

• Citations for Table 5:[0861]
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• Belrhali et al., (1999). Protein, lipid, and water organization in bacteriorhodopsin crystals: A molecular view of the purple membrane at 1.9 Å resolution.[0863]Structure7:909-917.
• Buchanan et al., (1999). Crystal Structure of the outer membrane active transporter FepA from[0864]Escherichia coli. Nature Struc. Biol.6:56-63.
• Chang et al., (1991). Structure of the membrane-bound protein photosynthetic reaction center from Rhodobacter sphaeroides.[0865]Biochemistry30, 5352-5360.
• Chang et al., (1998). Structure of the MscL homolog from Mycobacterium tuberculosis: A gated mechanosensitive ion channel.[0866]Science282, 2220-2226.
• Cowan et al., (1992). Crystal structures explain functional properties of two[0867]E. coliporins.Nature(London) 358, 727-733.
• Deisenhofer et al., (1985). Structure of the protein subunits in the photosynthetic reaction centre of Rhodospeudomonas viridis at 3 Å resolution.[0868]Nature (London)318, 618-624.
• Doyle et al., (1998). The structure of the potassium channel: Molecular basis of K+conduction and selectivity.[0869]Science280, 69-77.
• Edman et al., (1999). High-resolution X-ray structure of an early intermediate in the bacteriorhodopsin photocycle.[0870]Nature (London)401, 822-826.
• Essen et al., (1998). Lipid patches in membrane protein oligomers: crystal structure of the bacteriorhodopsin-lipid complex.[0871]Proc Natl Acad SciUSA 95:11673-11678.
• Ferguson et al., (1998). Siderophore-mediated iron transport: Crystal structure of FhuA with bound lipopolysaccharide.[0872]Science282, 2215-2220.
• Fu et al., (2000). Structure of a glycerol-conducting channel and the basis for its selectivity.[0873]Science290, 481-486.
• Grigorieff et al., (1996). Electron-crystallographic refinement of the structure of bacteriorhodopsin.[0874]J. Mol. Biol.259, 393-421.
• Hunte et al., (2000). Structure at 2.3 Å resolution of cytochrome bc1 complex from the yeast Saccharomyces cerevisiae co-crystallized with an antibody Fv fragment.[0875]Structure8:669-684.
• Iverson et al., (1999). Structure of the[0876]Escherichia colifumerate reductase respiratory complex.Science284, 1961-1966.
• Ivata et al., (1998). Complete structure of the 11-subunit bovine mitochondrial cytochrome bc1 complex.[0877]Science281, 64-71.
• Iwata et al., (1995). Structure at 2.8 Å resolution of cytochrome c oxidase from Paracoccusdenitrificans.[0878]Nature(London) 376, 660-669.
• Kimura et al., (1997). Surface of bacteriorhodopsin revealed by high-resolution electron crystallography.[0879]Nature(London) 389, 206-211.
• Koepke et al., (1996). The crystal structure of the light-harvesting complex II (B800-850) from Rhodospirillum molischianum.[0880]Structure4, 581-597.
• Kolbe et al., (2000). Structure of the light-driven chloride pump halorhodopsin at 1.8 Å.[0881]Science288, 1390-1396.
• Koronakis et al., (2000). Crystal structure of the bacterial membrane protein TolC central to multidrug efflux and protein export.[0882]Nature(London) 405, 914-919.
• Kurumbail et al., (1996). Structural basis for selective inhibition of cyclooxygenase-2 by anti-inflammatory agents.[0883]Nature(London) 384, 644-648.
• Kreusch et al., (1994). Structure of the membrane channel porin from Rhodopseudomonasblastica at 2.0 Å resolution.[0884]Protein Sci.3, 58-63.
• Lambert et al. (1999). An 8-A projected structure of FhuA, A “lignad-gated” channel of the[0885]Escherichia coliouter membrane,J Struct Biol126, 145-55
• Lancaster et al., (1999). Structure of rumarate reductase from Wolinella succinogenes at 2.2 Å resolution.[0886]Nature402, 377-385.
• Luecke, H., Rchter, H. T. & Lanyi, J. K. (1998). Proton transfer pathways in bacteriorhodopsin at[0887]2.3 Angstrom resolution.Science280, 1934-1937.
• Luecke et al., (1999). Structure of bacteriorhodopsin at 1.55 angstrom resolution.[0888]J. Mol. Biol.291, 899-911.
• Luecke et al., (1999). Structural changes in bacteriorhodopsin during ion transport at 2 angstrom resolution.[0889]Science286, 255-260.
• MacKenzie et al. (1997) A transmembrane helix dimer; structure and implications.[0890]Science276, 131-133.
• McDermott et al., (1995). Crystal structure of an integral membrane light-harvesting complex from photosynthetic bacteria.[0891]Nature(London) 374, 517-521.
• Meyer et al., (1997). Structure of maltoporin from Salmonella typhimurium ligated with a nitrophenyl-maltotrioside.[0892]J. Mol. Biol.266, 761-775.
• Murata et al., (2000). Structural determinants of water permeation through aquaporin-1.[0893]Nature407, 599-605.
• Olson et al., (1999). Crystal structure of Staphylococcal LukF delineated conformational changes accompanying formation of a transmembrane channel.[0894]Nature Struc. Biol.6, 134-140.
• Palczewski et al., (2000). Crystal structure of rhodopsin: A G protein-coupled receptor.[0895]Science289, 739-745.
• Pautsch and Schulz, (1998). Structure of the outer membrane protein A transmembrane domain.[0896]Nature Struct. Biol.5, 1013-1017.
• Pebay-Peyroula et al., (1997). X-ray structure of bacteriorhodopsin at 2.5 Å from microcrystals grown in lipidic cubic phases.[0897]Science277, 1676-1681.
• Picot et al., (1994). The x-ray crystal structure of the membrane protein prostaglandin H2 synthase-1.[0898]Nature(London) 367, 243-249.
• Preusch et al., (1998). Progress away from ‘no crystals, no grant’[0899]Nature Struct. Biol.5, 12-14.
• Ren et al., (2001). Visualization of a water-selective pore by electron crystallography in vitreous ice.[0900]Proc. Natl. Acad. Sci.USA 98, 1398-1403.
• Schirmer et al., (1995). Structural basis for sugar translocation through maltoporin channels at 3.1 A resolution.[0901]Science267, 512-4.
• Schubert et al., (1997). Photosystem I of Synechococcus elongatus at 4 Å resolution: Comprehensive structure analysis.[0902]J. Mol. Biol.272, 741-769.
• Snijder et al., (1999). Structural evidence for dimerization-regulated activation of an integral membrane phospholipase.[0903]Nature(London) 401, 717-721.
• Song et al., (1996). Structure of staphylococcal a -hemolysin, a heptameric transmembrane pore.[0904]Science274, 1859-1866.
• Soulimane et al., (2000). Structure and mechanism of th eaberrant ba(3)-cytochrome c oxidase from Thermus thermophilus.[0905]EMBO J.19, 1766-1776.
• Stock et al., (1999). Molecular architecture of rotary motor in ATP synthase.[0906]Science286, 1700-1705.
• Toyoshima et al., (2000). Crystal structure of the calcium pump of sarcoplasmic reticulum at 2.6 Å resolution.[0907]Nature405, 647-655.
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• Vogt and Schulz (1999). The structure of the outer membrane protein OmpX from[0909]Escherichia colireveals possible mechanisms of virulence.Structure Fold. Des.7, 1301-1309.
• Weiss and Schulz (1992). Structure of porin refined at 1.8 Å resolution.[0910]J. Mol. Biol.227, 493-509.
• Wendt et al., (1999). The structure of the membrane protein squalene-hopene cyclase at 2.0 Å resolution.[0911]J. Mol. Biol.286:175-187.
• White and Wimley (1999). Membrane protein folding and stability: Physical primciples.[0912]Annu. Rev. Biophys. Biomol. Struct.28:319-365.
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• Zouni et al., (2001). Crystal structure of photosystem II from Synechococcus elongatus at 3.8 Å resolution.[0916]Nature(London) 409:739-743.
• XVIII. Biosensors and Environmental Applications[0917]
• XVIII.A. Minicell-Based Biosensors[0918]
• The present invention is directed to a device that comprises a sensor adapted to detect one or more specific health and/or nutrition markers in a subject or in the environment. The device may also signal the caretaker, the subject, or an actuator of the occurrence. The sensor comprises a biosensor. As used herein, the term “biosensor” is defined as a component comprising one or more binding moities being adapted to detect a ligand found in one or more target pathogenic microorganisms or related biomolecules.[0919]
• Generally, biosensors function by providing a means of specifically binding, and therefore detecting, a target biologically active analyte. In this way, the biosensor is highly selective, even when presented with a mixture of many chemical and biological entities. Often the target biological analyte is a minor component of a complex mixture comprising a multiplicity of biological and other components. Thus, in many biosensor applications, detection of target analytes occurs in the parts-per-billion, parts-per-trillion, or even lower ranges levels.[0920]
• XVIII.A.1. Minicell-Based Biosensor Design[0921]
• The biosensor of the present invention may comprise a bio-recognition element, or molecular recognition element, that provides the highly specific binding or detection selectivity for a particular analyte. In a biosensor of the invention, the bio-recognition element, or system, is a minicell displaying an enzyme or sequence of enzymes; an antibody or antibody derivative; a membrane receptor protein; or the like, and generally functions to interact specifically with a target biological analyte. The bio-recognition element is responsible for the selective recognition of the analyte and the physico-chemical signal that provides the basis for the output signal. The expressed protein or molecule does not need to be a naturally occurring membrane bound protein but could be a soluble protein or small molecule thethered to the minicell by, for example, a transmembrane domain of another protein such as the EGFR or ToxR.[0922]
• Biosensors may include biocatalytic biosensors, and bioaffinity biosensors. In biocatalytic biosensor embodiments, the bio-recognition element minicell is “biocatalytic,” e.g., displays an enzyme. In biocatalytic biosensors, the selective binding sites “turn over” (i.e., can be used again during the detection process), resulting in a significant amplification of the input signal. Biocatalytic sensors such as these are generally useful for real-time, continuous sensing.[0923]
• Bioaffinity sensors are generally applicable to bacteria, viruses, toxins and other undesirable compounds and include chemoreceptor-based biosensors and/or immunological sensors (i.e., immunosensors). Chemoreceptors are complex biomolecular macroassemblies responsible, in part, for a viable organism's ability to sense chemicals in its environment with high selectivity. Chemoreceptor-based biosensors comprise one or more natural or synthetic chemoreceptors associated with a means to provide a signal (visual, electrical, etc.) of the presence or concentration of a target biological analyte. In certain embodiments, the chemoreceptor may be associated with an electrode (i.e., an electrical transducer) so as to provide a detectable electrical signal. In the biosensors of the invention, minicells displaying a receptor are used in place of chemoreceptors. The minicell has many desired features of a viable cell, and performs similar functions, but is more durable.[0924]
• On the other hand, the bio-recognition elements of immunosensors are generally antibodies or antibody derivatives. In any case, bioaffinity biosensors are generally irreversible because the receptor sites of the biosensor become saturated when exposed to the target biological analyte. In a biosensor of the invention, an immunosensor may be a minicell displaying an antibody or antibody fragment.[0925]
• Biocatalytic and bioaffinity biosensor systems are described in more detail in Journal of Chromatography, 510 (1990) 347-354 and in the Kirk-Othmer Encyclopedia of Chemical Technology, 4.sup.th ed. (1992), John Wiley & Sons, NY, the disclosure of which is incorporated by reference herein.[0926]
• The biosensors of the present invention may detect biologically active analytes related to impending (i.e., future presentation of symptoms is likely) or current human systemic disease states, including, but not limited to, pathogenic bacteria, parasites (e.g., any stage of the life cycle, including eggs or portions thereof, cysts, or mature organisms), viruses, fungi such as Candida albicans, antibodies to pathogens, and/or microbially produced toxins. Additionally, the biosensor may target biologically active analytes related to impending or current localized health issues, such as stress proteins (e.g., cytokines) and interleukin 1-alpha that may precede the clinical presentation of skin irritation or inflammation. In preferred embodiments, the biosensor functions as a proactive sensor, detecting and signaling the subject, a caretaker or medical personnel of the impending condition prior to the presentation of clinical symptoms. This allows time to administer prophylactic or remedial treatments to the subject which can significantly reduce, if not prevent, the severity and duration of the symptoms. Further, the sensor, by detecting the presence of a target biological analyte in a sample from the subject, may detect residual contamination on a surface, such as skin or environmental surface, in contact with the biosensor, and provide and appropriate signal.[0927]
• The physico-chemical signal generated by the bio-recognition element or elements may be communicated visually to the caretaker or medical personnel (i.e., via a color change visible to the human eye). Other embodiments may produce optical signals, which may require other instrumentation to enhance the signal. These include flourescence, bioluminesence, total internal reflectance resonance, surface plasmon resonance, Raman methods and other laser-based methods, such as LED or laser diode sensors. For example, exemplary surface plasmon resonance biosensors are available as IBIS I and IBIS II from XanTec Analysensysteme of Muenster, Germany, which may comprise bioconjugate surfaces as bio-recognition elements. Alternatively, the signal may be processed via an associated transducer which, for example, may produce an electrical signal (e.g., current, potential, inductance, or impedance) that may be displayed (e.g., on a readout such as an LED or LCD display) or which triggers an audible or tactile (e.g., vibration) signal or which may trigger an actuator, as described herein. The signal may be qualitative (e.g., indicating the presence of the target biological analyte) or quantitative (i.e., a measurement of the amount or concentration of the target biological analyte). In such embodiments, the transducer may optionally produce an optical, thermal or acoustic signal.[0928]
• In any case, the signal may also be durable (i.e., stable and readable over a length of time typically at least of the same magnitude as the usage life of the device) or transient (i.e., registering a real-time measurement). Additionally, the signal may be transmitted to a remote indicator site (e.g., via a wire, or transmitter, such as an infrared or rf transmitter) including other locations within or on the device or remote devices. Further, the sensor, or any of its components, may be adapted to detect and/or signal only concentrations of the target biological analyte above a predefined threshold level (e.g., in cases wherein the target biological analyte is normally present in the bodily waste or when the concentration of the analyte is below a known “danger” level).[0929]
• The target analytes that the biosensors of the present invention are adapted to detect may also be viruses. These may include diarrhea-inducing viruses such as rotavirus, or other viruses such as rhinovirus and human immunodeficiency virus (HIV). An exemplary biosensor adapted to detect HIV is described in U.S. Pat. Nos. 5,830,341 and 5,795,453, referenced above. The disclosure of each of these patents is incorporated by reference herein. Biosensors are adopted to use in different tissues; see, e.g., U.S. Pat. No. 6,342,037; Roe et al. Jan. 29, 2002; Device having fecal component sensor; and using different binding molecules, see, e.g., U.S. Pat. No. 6,329,160; Schneider et al. Dec. 11, 2001; Biosensors.[0930]
• When minicells are incorporated into a biosensor, they may be immobilized in the biosensor by techniques known in the art such as entrapment, adsorption, crosslinking, encapsulation, covalent attachment, any combination thereof, or the like. Further, the immobilization can be carried out on many different substrates such as known the art. In certain preferred embodiments, the immobilization substrate may be selected from the group of polymer-based materials, hydrogels, tissues, nonwoven materials or woven materials.[0931]
• In certain embodiments, biosensor embodiments, may comprise, be disposed on, or be operatively associated with a microchip, such as a silicon chip, MEMs (i.e., micro electromechanical system) device, or an integrated circuit. Microchip-based biosensors may be known as “biochips”. Regardless of the type of sensor, the microchip may comprise a multiplicity of sensor components having similar or different sensitivities, kinetics, and/or target analytes (i.e., markers) in an array adapted to detect differing levels or combinations of the analyte(s). Further, each sensor in such an array may provide a different type of signal, including those types disclosed herein, and may be associated with different actuators and/or controllers. Also, each sensor in an array may operate independently or in association with (e.g., in parallel, combination, or series) any number of other sensors in the array.[0932]
• A minicell of a biosensor of the invention may comprise a detectable compound that produces a signal once ligands have bound to the minicell. By way of non-limiting example, a minicell may display a receptor for a ligand and contain a fluorescent compound. The binding and internalization of the ligand into the minicell results in FRET, shifting the wavelength of the signal. See, by way of non-limiting example, Billinton et al., Development of a green fluorescent protein reporter for a yeast genotoxicity biosensor, Biosensors & Bioelectronics 13:831-838, 1998. A biosensor according to the invention may use microbalance sensor systems (Hengerer et al., Determination of phage antibody affinities to antigen by a microbalance sensor system, BioTechniques 26:956-964, 1999).[0933]
• XVIII.A.2. Surface Plasmon Resonance[0934]
• Kd is measured using surface plasmon resonance on a chip, for example, with a BIAcore® chip coated with immobilized binding components, or similar systems such as the lasys from Thermo Labsystems, Affinity Sensors Division (Cambridge, U.K.) or the BIOS-1 system from Artificial Sensing, Inc. (Zurich, Switzerland). See Fitzgerald, Coupling optical biosensor technology with micropreparative HPLC:[0935]Part 1, Am Biotech Lab November 2000, p.10 and 12; Fitzgerald, Coupling optical biosensor technology with micropreparative HPLC: Part 2, Am Biotech Lab February 2001, 14, 16 and 18; and Leatherbarrow et al., Analysis of molecualr recognition using optical sensors, Current Opinion in Chem Biol 3:544-547, 1999).
• Surface plasmon resonance is used to characterize the microscopic association and dissociation constants of reaction between an antibody or antibody fragment and its ligand. Such methods are generally described in the following references that are incorporated herein by reference. (Vely F. et al., BIAcore analysis to test phosphopeptide-SH2 domain interactions, Methods in Molecular Biology. 121:313-21, 2000; Liparoto et al., Biosensor analysis of the interleukin-2 receptor complex, Journal of Molecular Recognition. 12:316-21, 1999; Lipschultz et al., Experimental design for analysis of complex kinetics using surface plasmon resonance, Methods. 20):310-8, 2000; Malmqvist., BIACORE: an affinity biosensor system for characterization of biomolecular interactions, Biochemical Society Transactions 27:335-40, 1999; Alfthan, Surface plasmon resonance biosensors as a tool in antibody engineering, Biosensors & Bioelectronics. 13:653-63, 1998; Fivash et al., BIAcore for macromolecular interaction, Current Opinion in Biotechnology. 9:97-101, 1998; Price et al.; Summary report on the ISOBM TD-4 Workshop: analysis of 56 monoclonal antibodies against the MUC1 mucin. Tumour Biology 19 Suppl 1:1-20, 1998; Malmqvist et al, Biomolecular interaction analysis: affinity biosensor technologies for functional analysis of proteins, Current Opinion in Chemical Biology. 1:378-83, 1997; O'Shannessy et al., Interpretation of deviations from pseudo-first-order kinetic behavior in the characterization of ligand binding by biosensor technology, Analytical Biochemistry. 236:275-83, 1996; Malmborg et al., BIAcore as a tool in antibody engineering, Journal of Immunological Methods. 183:7-13, 1995; Van Regenmortel, Use of biosensors to characterize recombinant proteins, Developments in Biological Standardization. 83:143-51, 1994; O'Shannessy, Determination of kinetic rate and equilibrium binding constants for macromolecular interactions: a critique of the surface plasmon resonance literature, Current Opinions in Biotechnology. 5:65-71, 1994).[0936]
• BIAcore® uses the optical properties of surface plasmon resonance (SPR) to detect alterations in protein concentration bound within to a dextran matrix lying on the surface of a gold/glass sensor chip interface, a dextran biosensor matrix. In brief, proteins are covalently bound to the dextran matrix at a known concentration and a ligand for the protein (e.g., antibody) is injected through the dextran matrix. Near infra red light, directed onto the opposite side of the sensor chip surface is reflected and also induces an evanescent wave in the gold film, which in turn, causes an intensity dip in the reflected light at a particular angle known as the resonance angle. If the refractive index of the sensor chip surface is altered (e.g., by ligand binding to the bound protein) a shift occurs in the resonance angle. This angle shift can be measured and is expressed as resonance units (RUs) such that 1000 RUs is equivalent to a change in surface protein concentration of 1 ng/mm2. These changes are displayed with respect to time along the y-axis of a sensorgram, which depicts the association and dissociation of any biological reaction.[0937]
• Additional details may be found in Jonsson et al., Introducing a biosensor based technology for real-time biospecific interaction analysis, (1993) Ann. Biol. Clin. 51:19-26; Jonsson et al., Real-time biospecific interaction analysis using surface plasmon resonance and a sensor chip technology, (1991) Biotechniques 11:620-627; Johnsson et al., Comparison of methods for immobilization to carboxymethyl dextran sensor surfaces by analysis of the specific activity of monoclonal antibodies, (1995) J. Mol. Recognit. 8:125-131; and Johnsson, Immobilization of proteins to a carboxymethyldextran-modified gold surface for biospecific interaction analysis in surface plasmon resonance sensors (1991) Anal. Biochem. 198:268-277, Karlsson et. al., Kinetic analysis of monoclonal antibody-antigen interactions with a new biosensor based analytical system J. Immunol. Meth., 145, 229, 1991; Weinberger et al., Recent trends in protein biochip technology, Pharmacogenomics November 2000; 1(4):395-416; Lipschultz et al., Experimental design for analysis of complex kinetics using surface plasmon resonance, Methods March 2000;20(3):310-8.[0938]
• XVIII.B. Toxicological Sampling[0939]
• Minicells are ideally suited for in vitro diagnostic toxicological applications in which toxins, poisons, infectious agents or pathogens, heavy metals, pollutants, caustic agents, allergens, organic molecules, radionuclides, or other environmental contaminants present either in air, water, soil samples and/or fluid and/or tissue samples of organisms can be assessed. An embodiment of this invention, minicells expressing proteins or other molecules could be used in variety of diagnostic detection platforms, including microwell formats, lateral flow devices, molecular switches, biosensors, badges and other sensing devices. Without being limited to the following examples, such devices could be used for early warning of chemical and/or bioweapon attack, illegal drug detection, explosives detection, biohazard detection, pollution assessment, pesticide contamination, allergen detection and detection of toxic or hazardous gasses. In a related application, minicells could be used to eliminate, modify or inactivate the agents.[0940]
• In one non-limiting example of protein expression on minicells for toxicological detection, olfactory receptors could be expressed by minicells. The olfactory system possesses the ability to recognize and differentiate between a wide range of odorants based on odor molecules interacting with specific receptor proteins in the ciliary membrane of olfactory neurons (Lancet, D., 1986. Vertebrate olfactory reception. Ann. Rev. Neurosci. 9:329-355; Shepherd, G. M., 1994. Discrimination of molecular signals by the olfactory receptor neuron. Neuron 13:771-790). These receptors were found to be 7-transmembrane-domain members of the G protein-coupled receptor family (Buck, L. and R. Alex. 1991. A novel multigene family may encode odorant receptors: A molecular basis for odor recognition. Cell 65:175-187). Using a murine receptor library, olfactory receptors were functionally expressed in HEK-293 cells (Krautwurst, D., et al., 1998. Identification of ligands for olfactory receptors by functional expression of a receptor library. Cell. 95:917-926). By coexpressing the cloned receptors with G 15,16 subunits, the modified receptor system upon activation leads to an increase in intracellular Ca[0941]²⁺. Calcium levels were measured employing the dye FURA-2 and ratiofluormetric imaging. This system demonstrated ligand specificity and structure-function relationships for identified olfactory receptors. Employing similar techniques, OR17-40, a human olfactory receptor protein, was expressed in human embryonic kidney 293 cells and Xenopus Laevis oocytes (Wetzel, H., et al. 1999. Specificity and sensitivity of a human olfactory receptor functionally expressed in Human Embryonic Kidney 293 Cells and Xenopus Laevis Oocytes. J. Neurosciences. 19:7426-7433). The receptor was functionally expressed in a manner designed to assess the specificity of its binding to the ligand, helional.
• In one non-limiting example of target protein identification, primers from homologous areas in transmembrane II and transmembrane VII of olfactory GPCRs will be used to identify unique receptor sequences. These sequences are inserted into expression vectors. Minicell producing bacteria are transformed with these vectors and cultured. Minicells are isolated from the culture as previously described and subsequently induced. Using HTS previously described, the functional receptor/minicells which generate signal for binding of an odiferous toxin to the receptor are identified. Large scaleLarge-scale production of the minicells is carried out and the minicells are covalently coupled to the surface of a microarraymicro array chip. The chip is supported in an air sampler,, which feeds atmosphere over surface of the chip on a continuous basis. If the toxic agent is present in the air, the binding to the receptor activates a series of events ending in the generation of a signal identifying the presence of the agent in the air.[0942]
• By way of non-limiting example, standard molecular biological techniques can be used as follows: cDNA for GFP is ligated to the 3′ end of cDNA sequence for the receptor described above. The resulting sequence is inserted into an expression vector. Minicell producing bacteria are transformed with these vectors and cultured. Minicells are isolated from the culture as previously described and subsequently induced. The minicells now contain the receptor to the ligand on the surface of the minicell with a GFP tag on the C-terminus of the protein in the cytosol. These minicells are packed into filters. Air is passed through the filter. If the ligand is present, it will bind to the receptor. The filter packing is suspended on applied to a diagnostic device. Antibody to the ligand/receptor binding site complex is fixed on the capture zone. When the sample is applied to the device, the receptor/ligand complex is captured. The capture zone is screened for signal resulting from the presence of GFP. This can be extrapolated to have multiple unique receptor/minicell moieties in the same sampling device. Each receptor would have a unique fluorescing protein tag such that different emissions identify specific agents in the air.[0943]
• Other methods for quantification associated take advantage of the composition of the minicell. Loading of the minicell by transiently permeabilizing the membrane to allow for migration of molecules into to the cytosol. These molecules include but are not limited to radiolabeled molecules (i.e., nucleotides), stains or dyes (DAPI or other DNA staining, heavy metals, fluorophores. The molecules could also be synthesized within the minicell (i.e. GFP). The association of a specific ligand with the minicell could cause a redox shift that induce a color change in the solution or could shift the energy potential in the reaction are generating an electrical current. Each of this examples are associated with well know methods for measuring each of the resulting changes. These include but are not limited to radioactivity or fluorescence generated or the color shift by spectrophotometry.[0944]
• A multigene family of gustatory G protein-coupled receptors expressed in the lingual epithelia has been identified with structural similarities to olfactory receptors (Abe, K., et al. 1993. Multiple genes for G protein-coupled receptors and their expression in lingual epithelia. FEBS. 316:253-256; Abe, K., et al. 1993. Primary structure and cell-type specific expression of a gustatory G protein-coupled receptor related to olfactory receptors. J. Bio. Chem.). This provides an addition example of receptors which can be isolated, expressed in minicells and then be used for identification of specific substances in various matrices in similar manners as identified for olfactory receptor minicells.[0945]
• As a non-limiting example of minicell use in toxicological/environmental detection, arrays could be constructed in which each well contains a distinct minicell subtype displaying membrane-bound proteins or other molecules for each of several potential toxins or agents in the environment. For example, minicells in such a format could be used to determine which agents are present in the environment as a consequence of a chemical and/or biological weapons attack. Non-limiting examples of biosensors that have been used toxicological/environmental detection include those described by Sticher et al., Development and characterization of a whole-cell bioluminescent sensor for bioavailable middle-chain alkanes in contaminated groundwater samples, Appl. Envir. Microbiol. 63:4053-4060, 1997; Willardson et al., Development and Testing of a Bacterial Biosensor for Toluene-Based Environmental Contaminants, Appl. Envir. Microbiol. 64:1006-1012, 1998; Lars et al., Detection of Oxytetracycline Production by Streptomyces rimosus in Soil Microcosms by Combining Whole-Cell Biosensors and Flow Cytometry, Appl. Envir. Microbiol. 67:239-244, 2001; Højberg et al., Oxygen-Sensing Reporter Strain of Pseudomonas fluorescens for Monitoring the Distribution of Low-Oxygen Habitats in Soil, Appl. Envir. Microbiol. 1999 65: 4085-4093, 1999; R. P. Hollis et al., Design and Application of a Biosensor for Monitoring Toxicity of Compounds to Eukaryotes, Appl. Envir. Microbiol. 66: 1676-1679, 2000; Heitzer et al., Optical biosensor for environmental on-line monitoring of naphthalene and salicylate bioavailability with an immobilized bioluminescent catabolic reporter bacterium, Appl. Envir. Microbiol. 60:1487-1494, 1994; Selifonova et al., Bioluminescent sensors for detection of bioavailable Hg(II) in the environment, Appl. Envir. Microbiol. 59: 3083-3090, 1993; Jaeger et al., Mapping of Sugar and Amino Acid Availability in Soil around Roots with Bacterial Sensors of Sucrose and Tryptophan, Appl. Envir. Microbiol. 65: 2685-2690, 1999; and Larsen et al., A Microsensor for Nitrate Based on Immobilized Denitrifying Bacteria, Appl. Envir. Microbiol. 62: 1248-1251, 1996.[0946]
• XVIII.C. Toxin Elimination[0947]
• In another embodiment of the invention, minicells displaying a receptor for a particular toxic agent could be used for the elimination of the agent from the environment. In a non-limiting example of this technology, minicells could be placed in a filtering apparatus to eliminate the toxic agent from the environment (e.g., air, water soil). In the example of atmospheric contamination, the air would be circulated through a forced air system containing in-line filters composed of a housing, support matrix and receptor/minicells. As air passes over the minicells, the toxin is bound to the receptor. The purified air passed out of the system and into the atmosphere. A similar method for water purification would follow a similar protocol replacing the receptor for the toxin with the receptor or other protein binding a unique epitope on contaminant wishing to be removed. Examples include but are not limited to removing toxins, parasites or microbes from the matrix such as water or air. This represent non-limiting example of minicell-based technology for expression of functional receptors or binding moieties of receptors on the minicell's surface for the specific purpose of selectively capturing, identifying, quantifying and/or removing molecules of interest for environmental compartments to include but not limited to air water, soil, other gas phases or liquid solutions.[0948]
• Representative toxins include, but are not limited to, those associated with “red tides”; eubacterial toxins, such as those toxins produced by[0949]Corynebacterium diphtheriae(diphtheria),Bordetella pertussis(whooping cough),Vibrio cholerae(cholera),Bacillus anthracis(anthrax),Clostridium botulinum(botulism),Clostridium tetani(tetanus), and enterohemorrhagicEscherichia coli(bloody diarrhea and hemolytic uremic syndrome); and fungal toxins (e.g., aflatoxin, gliotoxin, cyclopeptides, orellanine, gyrometrin, coprine, muscarine, ibotenic acid, psilocybin, psilocin and baeocystin).
• The treatment of “red tides” with minicells exemplifies this aspect of the invention. A red tide occurs as a result of a higher-than-normal concentration of an algae or dinoflagellate which, when present in dense concentrations as a result of a “bloom,” form colored patches on the surface of water. The colored patches are pink, violet, orange, yellow, blue, green, brown, or red, with red being the most common color. The organisms that cause red tides often produce toxins that have negative impacts on other organisms, including humans.[0950]
• For example, Karenia brevis (formerly[0951]Gymnodinium breve) produces a toxin (domoic acid) that affects the central nervous system of fish, shellfish and other organisms, resulting in a state of paralysis. Alexandrium species (e.g.,A. tamarense, A. fundyense), Dinophysis and Gonyaulax species; and Pseudo-nitzschia multiseries, which cause, respectively, paralytic, diarrhetic and amnesic shellfish poisoning. Because shellfish containing the toxin taste and appear the same as shellfish that do not, and cooking does not destroy the toxin, human ingestion of the former can cause disease in humans and other organisms. For example, one form of paralytic shellfish poisoning, which can be fatal to humans, results from saxitoxin, which is produced byGonyaulax tamarenis, Protogonyaulax catanella,and other species. Other algae that can result in red tides includeGonyaulax catenella,andPtychdiscus breve.
• Minicells that comprise a binding moiety of an organism that produces a red tide, or of the toxin produced thereby, can be used for remediation. For example, a minicell having a binding moiety directed to a red tide-producing organism can be used to deliver an antibiotic thereto, and a minicell with a binding moiety directed to a toxin can be used to bind and/or internalize the toxin. As is explained in more detail elsewhere herein, a minicell with a binding moiety directed to a toxin can also be used for therapeutic purposes.[0952]
• XVIII.D. Bioremediation[0953]
• In another non-limiting example of the potential use of minicells in a toxicological context is their use in bioremediation, the process by which living organisms act to degrade or transform hazardous organic contaminants. As used herein, “bioremediation” is the process of using biological or biologically derived compositions that alter the chemical structure and/or bind, an undesirable substance in order to reduce the effective concentration of the undesirable substance, thereby reducing or eliminating the effect(s) of the undesirable compound on the environment. Undesirable substances include, but are not limited to, pollutants (e.g., heavy metals, pesticides, herbicides, petroleum products); biological toxins (e.g., such as those produced by “red tides”, e.g., domoic acid, saxitoxin); pathogens (e.g., viruses, eubacteria); organisms that produce toxins; biological waste products (e.g., sewage, guano), and undesirable organisms therewithin (e.g., pathogenic eubacteria).[0954]
• The term “bioremediation” encompasess both biodegradation, the breakdown of organic substances by microorganisms, and biotransformation, the alteration of the structure of a compound by a living organism or enzyme. The minicells of the invention may be incorporated into biofilters, i.e., devices in which gases, liquids, powders and the like are passed through media containing biodegrading minicells, including but not limited to devices that biodegrade volatile organic compounds in air by passing the air therethrough.[0955]
• Bioremedation can be used to process undesirable substances in a composition prior to or after the release of the composition into the environment. For example, bioremediation can be applied in sewage treatment plants to process sewage prior to its release, or to sewage that has been accidentally or otherwise released into the environment.[0956]
• Environmental microbiologists have sought to identify and use specific bacteria that degrade pollutants and other environmental containments. See, for example, Chakrabarty, Microbial Degradation of Toxic Chemicals: Evolutionary Insights and Practical Considerations, Am. Soc. Micro. Biol. News 62:130-137, 1996; and U.S. Pat. Nos. 4,511,657; 4,493,895; 4,871,673; and 4,535,061. In instances where a live organism is placed into the environment to process undesirable substances, there is a concern that the organism might have undesirable effects that would be made more deleterious due to the ability of the live organism to replicate (Sayler GS, Ripp S. Field applications of genetically engineered microorganisms for bioremediation processes. Curr Opin Biotechnol. June 2000;11(3):286-9; and Diaz E, Ferrandez A, Prieto M A, Garcia J L. Biodegradation of aromatic compounds by[0957]Escherichia coli.Microbiol Mol Biol Rev. December 2001 65(4):523-69). For example, when it has been proposed to use genetically altered eubacteria to process oil spills, the concern has been raised that the eubacteria might spread beyond the oil spill and into supplies of petroleum products that are used to produce energy, where they would process and render useless the stored petroleum products. However, because they lack the ability to replicate, such a scenario will not occur when minicells are use for bioremediation.
• By way of non-limiting example, octane enhances such as methyl t-butyl ether or aromatic hydrocarbons contaminate the aquifer and soil. These agents negatively impact the many microbes in the effected area thus limiting capability of the microbial community rectify the environmental insult. Bioaugmentation, the addition to the environment of microorganisms that can metabolize and grow on specific organic compounds, to facilitate degradation may porove useful, but concerns exist relative to the regulation of newly introduced bacteria. The minicell provides a vehicle to accomplish biodegradation without bacterial overgrowth.[0958]
• Diphenyl ethers and cyclic ethers such as dioxane and furan have shown to be metabolized by soil bacteria. Using classic isolation and screening techniques identified above, genes encoding for the oxygenases or hydroylases are isolated. The enzyme sequence is inserted into an expression vector using standard molecular biology techniques. Minicell producing bacteria are transformed with these vectors and cultured. Minicells are isolated from the culture as previously described and subsequently induced. The minicells are applied to the area contaminated with aromatic hydrocarbons. These compounds are transported either actively or passively in to the minicell and subsequently degraded by the oxygenase or hydroylase. One advantage of this focused degradation is the minimizing of feedback inhibition because the only machinery of consequence in the minicell is that related to the degradation of the ether compounds.[0959]
• Similarly, beginning with genetic material from Dehalobacter enzymes responsible for the biodegrading of tetrachloroethane could be isolated as described above. The sequence for the enzyme is inserted into the expression vector and used to transform minicell-producing bacteria. The bacteria are cultured, minicells isolated from the culture and the minicells induced as previously described. Minicell preps are lyophilized using standard lyophilization techniques. The resulting material is transported to the site of tetrachloroethene contamination and reconstituted and applied. As the tetracholoethene was assimilated, it is be degraded by the enzyme system.[0960]
• These are non-limiting examples scope of bioremediation/biotranformation using minicell technology. The scope of the invention includes taking advantage of metabolic pathways organism in general to include but not limited to eukaryotes, prokaryotes, fungi, animals or plants.[0961]
• XVIII.E. Fermentation[0962]
• Delivery of specific enzymes in an untargeted fashion by the minicell allows for packaged delivery without the increased biomass and complex metabolic products associated with processes using live organisms. This aspect can be taken advantage of in fermentation, where the addition of minicells into which unique enzymes have been added are used to modulate the composition of the environment to include but not limited to the alcohol, sugar and acid levels.[0963]
• XVIII.F. Pesticides[0964]
• [0965]Bacillus thurigenesisproduces a toxin that kills plant chewing insect larvae as well as mosquito larvae. The toxin, Cry1Ac, binds to aminopeptidase N receptor on the endothelium of the midgut. Minicell technology is allows for delivery of the toxin. The toxin sequence is modified by ligation of a sequence coding for a transmembrane domain as previously described. The sequence for this fusion protein inserted into an expression vector using standard molecular biology techniques. To facilitate the consumption of the toxin/minicell plasmids containing sequences incorporating the sequence for pheromones coupled at the C-terminus to the sequence for a transmembrane domain is generated using standard molecular biological techniques. This fusion protein sequence is inserted into the expression containing coding region for the toxin fusion protein or inserted into a unique expression vector. Minicell producing bacteria are transformed with these vectors and cultured. Minicells are isolated from the culture as previously described and subsequently induced. The minicells are distributed (e.g crop dusting) to the area of infestation. The toxin/minicells are ingested by the larvae and kill the larvae as the minicells passes through the gut.
• XIX. Pharmaceutical Compositions[0966]
• Another aspect of the invention is drawn to compositions, including but not limited to pharmaceutical compositions. According to the invention, a “composition” refers to a mixture comprising at least one carrier, preferably a physiologically acceptable carrier, and one or more minicell compositions. The term “carrier” defines a chemical compound that does not inhibit or prevent the incorporation of the biologically active peptide(s) into cells or tissues. A carrier typically is an inert substance that allows an active ingredient to be formulated or compounded into a suitable dosage form (e.g., a pill, a capsule, a gel, a film, a tablet, a microparticle (e.g., a microsphere), a solution; an ointment; a paste, an aerosol, a droplet, a colloid or an emulsion etc.). A “physiologically acceptable carrier” is a carrier suitable for use under physiological conditions that does not abrogate (reduce, inhibit, or prevent) the biological activity and properties of the compound. For example, dimethyl sulfoxide (DMSO) is a carrier as it facilitates the uptake of many organic compounds into the cells or tissues of an organism. Preferably, the carrier is a physiologically acceptable carrier, preferably a pharmaceutically or veterinarily acceptable carrier, in which the minicell composition is disposed.[0967]
• A “pharmaceutical composition” refers to a composition wherein the carrier is a pharmaceutically acceptable carrier, while a “veterinary composition” is one wherein the carrier is a veterinarily acceptable carrier. The term “pharmaceutically acceptable carrier” or “veterinarily acceptable carrier” includes any medium or material that is not biologically or otherwise undesirable, i.e., the carrier may be administered to an organism along with a minicell composition without causing any undesirable biological effects or interacting in a deleterious manner with the complex or any of its components or the organism. Examples of pharmaceutically acceptable reagents are provided in The United States Pharmacopeia, The National Formulary, United States Pharmacopeial Convention, Inc., Rockville, Md. 1990, hereby incorporated by reference herein into the present application. The terms “therapeutically effective amount” or “pharmaceutically effective amount” mean an amount sufficient to induce or effectuate a measurable response in the target cell, tissue, or body of an organism. What constitutes a therapeutically effective amount will depend on a variety of factors, which the knowledgeable practitioner will take into account in arriving at the desired dosage regimen.[0968]
• The compositions of the invention can further comprise other chemical components, such as diluents and excipients. A “diluent” is a chemical compound diluted in a solvent, preferably an aqueous solvent, that facilitates dissolution of the composition in the solvent, and it may also serve to stabilize the biologically active form of the composition or one or more of its components. Salts dissolved in buffered solutions are utilized as diluents in the art. For example, preferred diluents are buffered solutions containing one or more different salts. A preferred buffered solution is phosphate buffered saline (particularly in conjunction with compositions intended for pharmaceutical administration), as it mimics the salt conditions of human blood. Since buffer salts can control the pH of a solution at low concentrations, a buffered diluent rarely modifies the biological activity of a biologically active peptide.[0969]
• An “excipient” is any more or less inert substance that can be added to a composition in order to confer a suitable property, for example, a suitable consistency or to form a drug. Suitable excipients and carriers include, in particular, fillers such as sugars, including lactose, sucrose, mannitol, or sorbitol cellulose preparations such as, for example, maize starch, wheat starch, rice starch, agar, pectin, xanthan gum, guar gum, locust bean gum, hyaluronic acid, casein potato starch, gelatin, gum tragacanth, methyl cellulose, hydroxypropylmethyl-cellulose, polyacrylate, sodium carboxymethylcellulose, and/or polyvinylpyrrolidone (PVP). If desired, disintegrating agents can also be included, such as cross-linked polyvinyl pyrrolidone, agar, or alginic acid or a salt thereof such as sodium alginate. Other suitable excipients and carriers include hydrogels, gellable hydrocolloids, and chitosan. Chitosan microspheres and microcapsules can be used as carriers. See WO 98/52547 (which describes microsphere formulations for targeting compounds to the stomach, the formulations comprising an inner core (optionally including a gelled hydrocolloid) containing one or more active ingredients, a membrane comprised of a water insoluble polymer (e.g., ethylcellulose) to control the release rate of the active ingredient(s), and an outer layer comprised of a bioadhesive cationic polymer, for example, a cationic polysaccharide, a cationic protein, and/or a synthetic cationic polymer; U.S. Pat. No. 4,895,724. Typically, chitosan is cross-linked using a suitable agent, for example, glutaraldehyde, glyoxal, epichlorohydrin, and succinaldehyde. Compositions employing chitosan as a carrier can be formulated into a variety of dosage forms, including pills, tablets, microparticles, and microspheres, including those providing for controlled release of the active ingredient(s). Other suitable bioadhesive cationic polymers include acidic gelatin, polygalactosamine, polyamino acids such as polylysine, polyhistidine, polyornithine, polyquaternary compounds, prolamine, polyimine, diethylaminoethyldextran (DEAE), DEAE-imine, DEAE-methacrylate, DEAE-acrylamide, DEAE-dextran, DEAE-cellulose, poly-p-aminostyrene, polyoxethane, copolymethacrylates, polyamidoamines, cationic starches, polyvinylpyridine, and polythiodiethylaminomethylethylene.[0970]
• The compositions of the invention can be formulated in any suitable manner. Minicell compositions may be uniformly (homogeneously) or non-uniformly (heterogenously) dispersed in the carrier. Suitable formulations include dry and liquid formulations. Dry formulations include freeze dried and lyophilized powders, which are particularly well suited for aerosol delivery to the sinuses or lung, or for long term storage followed by reconstitution in a suitable diluent prior to administration. Other preferred dry formulations include those wherein a composition according to the invention is compressed into tablet or pill form suitable for oral administration or compounded into a sustained release formulation. When the composition is intended for oral administration but is to be delivered to epithelium in the intestines, it is preferred that the formulation be encapsulated with an enteric coating to protect the formulation and prevent premature release of the minicell compositions included therein. As those in the art will appreciate, the compositions of the invention can be placed into any suitable dosage form. Pills and tablets represent some of such dosage forms. The compositions can also be encapsulated into any suitable capsule or other coating material, for example, by compression, dipping, pan coating, spray drying, etc. Suitable capsules include those made from gelatin and starch. In turn, such capsules can be coated with one or more additional materials, for example, and enteric coating, if desired. Liquid formulations include aqueous formulations, gels, and emulsions.[0971]
• Some preferred embodiments concern compositions that comprise a bioadhesive, preferably a mucoadhesive, coating. A “bioadhesive coating” is a coating that allows a substance (e.g., a minicellcomposition) to adhere to a biological surface or substance better than occurs absent the coating. A “mucoadhesive coating” is a preferred bioadhesive coating that allows a substance, for example, a composition according to the invention, to adhere better to mucosa occurs absent the coating. For example, micronized particles (e.g., particles having a mean diameter of about 5, 10, 25, 50, or 100 μm) can be coated with a mucoadhesive. The coated particles can then be assembled into a dosage form suitable for delivery to an organism. Preferably, and depending upon the location where the cell surface transport moiety to be targeted is expressed, the dosage form is then coated with another coating to protect the formulation until it reaches the desired location, where the mucoadhesive enables the formulation to be retained while the composition interacts with the target cell surface transport moiety.[0972]
• The compositions of the invention may be administered to any organism, preferably an animal, preferably a mammal, bird, fish, insect, or arachnid. Preferred mammals include bovine, canine, equine, feline, ovine, and porcine animals, and non-human primates. Humans are particularly preferred. Multiple techniques of administering or delivering a compound exist in the art including, but not limited to, oral, rectal (e.g. an enema or suppository) aerosol (e.g., for nasal or pulmonary delivery), parenteral, and topical administration. Preferably, sufficient quantities of the biologically active peptide are delivered to achieve the intended effect. The particular amount of composition to be delivered will depend on many factors, including the effect to be achieved, the type of organism to which the composition is delivered, delivery route, dosage regimen, and the age, health, and sex of the organism. As such, the particular dosage of a composition incorporated into a given formulation is left to the ordinarily skilled artisan's discretion.[0973]
• Those skilled in the art will appreciate that when the compositions of the present invention are administered as agents to achieve a particular desired biological result, which may include a therapeutic or protective effect(s) (including vaccination), it may be necessary to combine the fusion proteins of the invention with a suitable pharmaceutical carrier. The choice of pharmaceutical carrier and the preparation of the fusion protein as a therapeutic or protective agent will depend on the intended use and mode of administration. Suitable formulations and methods of administration of therapeutic agents include those for oral, pulmonary, nasal, buccal, ocular, dermal, rectal, or vaginal delivery.[0974]
• Depending on the mode of delivery employed, the context-dependent functional entity can be delivered in a variety of pharmaceutically acceptable forms. For example, the context-dependent functional entity can be delivered in the form of a solid, solution, emulsion, dispersion, micelle, liposome, and the like, incorporated into a pill, capsule, tablet, suppository, areosol, droplet, or spray. Pills, tablets, suppositories, areosols, powders, droplets, and sprays may have complex, multilayer structures and have a large range of sizes. Aerosols, powders, droplets, and sprays may range from small (1 micron) to large (200 micron) in size.[0975]
• Pharmaceutical compositions of the present invention can be used in the form of a solid, a lyophilized powder, a solution, an emulsion, a dispersion, a micelle, a liposome, and the like, wherein the resulting composition contains one or more of the compounds of the present invention, as an active ingredient, in admixture with an organic or inorganic carrier or excipient suitable for enteral or parenteral applications. The active ingredient may be compounded, for example, with the usual non-toxic, pharmaceutically acceptable carriers for tablets, pellets, capsules, suppositories, solutions, emulsions, suspensions, and any other form suitable for use. The carriers which can be used include glucose, lactose, mannose, gum acacia, gelatin, mannitol, starch paste, magnesium trisilicate, talc, corn starch, keratin, colloidal silica, potato starch, urea, medium chain length triglycerides, dextrans,and other carriers suitable for use in manufacturing preparations, in solid, semisolid, or liquid form. In addition auxiliary, stabilizing, thickening and coloring agents and perfumes may be used. Examples of a stabilizing dry agent includes triulose, preferably at concentrations of 0.1% or greater (See, e.g., U.S. Pat. No. 5,314,695). The active compound is included in the pharmaceutical composition in an amount sufficient to produce the desired effect upon the process or condition of diseases.[0976]
• XX. Small Molecules[0977]
• The term “small molecule” includes any chemical or other moiety that can act to affect biological processes. Small molecules can include any number of therapeutic agents presently known and used, or can be small molecules synthesized in a library of such molecules for the purpose of screening for biological function(s). Small molecules are distinguished from macromolecules by size. The small molecules of this invention usually have molecular weight less than about 5,000 daltons (Da), preferably less than about 2,500 Da, more preferably less than 1,000 Da, most preferably less than about 500 Da.[0978]
• Small molecules include without limitation organic compounds, peptidomimetics and conjugates thereof. As used herein, the term “organic compound” refers to any carbon-based compound other than macromolecules such nucleic acids and polypeptides. In addition to carbon, organic compounds may contain calcium, chlorine, fluorine, copper, hydrogen, iron, potassium, nitrogen, oxygen, sulfur and other elements. An organic compound may be in an aromatic or aliphatic form. Non-limiting examples of organic compounds include acetones, alcohols, anilines, carbohydrates, monosaccharides, oligosaccharides, polysaccharides, amino acids, nucleosides, nucleotides, lipids, retinoids, steroids, proteoglycans, ketones, aldehydes, saturated, unsaturated and polyunsaturated fats, oils and waxes, alkenes, esters, ethers, thiols, sulfides, cyclic compounds, heterocylcic compounds, imidizoles and phenols. An organic compound as used herein also includes nitrated organic compounds and halogenated (e.g., chlorinated) organic compounds. Methods for preparing peptidomimetics are described below. Collections of small molecules, and small molecules identified according to the invention are characterized by techniques such as accelerator mass spectrometry (AMS; see Turteltaub et al., Curr Pharm Des 2000 6(10):991-1007, Bioanalytical applications of accelerator mass spectrometry for pharmaceutical research; and Enjalbal et al., Mass Spectrom Rev 2000 19(3): 139-61, Mass spectrometry in combinatorial chemistry.)[0979]
• Preferred small molecules are relatively easier and less expensively manufactured, formulated or otherwise prepared. Preferred small molecules are stable under a variety of storage conditions. Preferred small molecules may be placed in tight association with macromolecules to form molecules that are biologically active and that have improved pharmaceutical properties. Improved pharmaceutical properties include changes in circulation time, distribution, metabolism, modification, excretion, secretion, elimination, and stability that are favorable to the desired biological activity. Improved pharmaceutical properties include changes in the toxicological and efficacy characteristics of the chemical entity.[0980]
• XXI. Polypeptides and Derivatives[0981]
• XXI.A. Polypeptides[0982]
• As used herein, the term “polypeptide” includes proteins, fusion proteins, oligopeptides and polypeptide derivatives, with the exception that peptidomimetics are considered to be small molecules herein. Although they are polypeptides, antibodies and their derivatives are described in a separate section. Antibodies and antibody derivatives are described in a separate section, but antibodies and antibody derivatives are, for purposes of the invention, treated as a subclass of the polypeptides and derivatives.[0983]
• A “protein” is a molecule having a sequence of amino acids that are linked to each other in a linear molecule by peptide bonds. The term protein refers to a polypeptide that is isolated from a natural source, or produced from an isolated cDNA using recombinant DNA technology; and has a sequence of amino acids having a length of at least about 200 amino acids.[0984]
• A “fusion protein” is a type of recombinant protein that has an amino acid sequence that results from the linkage of the amino acid sequences of two or more normally separate polypeptides.[0985]
• A “protein fragment” is a proteolytic fragment of a larger polypeptide, which may be a protein or a fusion protein. A proteolytic fragment may be prepared by in vivo or in vitro proteolytic cleavage of a larger polypeptide, and is generally too large to be prepared by chemical synthesis. Proteolytic fragments have amino acid sequences having a length from about 200 to about 1,000 amino acids.[0986]
• An “oligopeptide” is a polypeptide having a short amino acid sequence (i.e., 2 to about 200 amino acids). An oligopeptide is generally prepared by chemical synthesis.[0987]
• Although oligopeptides and protein fragments may be otherwise prepared, it is possible to use recombinant DNA technology and/or in vitro biochemical manipulations. For example, a nucleic acid encoding an amino acid sequence may be prepared and used as a template for in vitro transcription/translation reactions. In such reactions, an exogenous nucleic acid encoding a preselected polypeptide is introduced into a mixture that is essentially depleted of exogenous nucleic acids that contains all of the cellular components required for transcription and translation. One or more radiolabeled amino acids are added before or with the exogenous DNA, and transcription and translation are allowed to proceed. Because the only nucleic acid present in the reaction mix is the exogenous nucleic acid added to the reaction, only polypeptides encoded thereby are produced, and incorporate the radiolabelled amino acid(s). In this manner, polypeptides encoded by a preselected exogenous nucleic acid are radiolabeled. Although other proteins are present in the reaction mix, the preselected polypeptide is the only one that is produced in the presence of the radiolabeled amino acids and is thus uniquely labeled.[0988]
• As is explained in detail below, “polypeptide derivatives” include without limitation mutant polypeptides, chemically modified polypeptides, and peptidomimetics.[0989]
• The polypeptides of this invention, including the analogs and other modified variants, may generally be prepared following known techniques. Preferably, synthetic production of the polypeptide of the invention may be according to the solid phase synthetic method. For example, the solid phase synthesis is well understood and is a common method for preparation of polypeptides, as are a variety of modifications of that technique [Merrifield (1964), J. Am. Chem. Soc., 85: 2149; Stewart and Young (1984), Solid Phase polypeptide Synthesis, Pierce Chemical Company, Rockford, Ill.; Bodansky and Bodanszky (1984), The Practice of polypeptide Synthesis, Springer-Verlag, New York; Atherton and Sheppard (1989), Solid Phase polypeptide Synthesis: A Practical Approach, IRL Press, New York]. See, also, the specific method described in Example 1 below.[0990]
• Alternatively, polypeptides of this invention may be prepared in recombinant systems using polynucleotide sequences encoding the polypeptides. For example, fusion proteins are typically prepared using recombinant DNA technology.[0991]
• XXI.B. Polypeptide Derivatives[0992]
• A “derivative” of a polypeptide is a compound that is not, by definition, a polypeptide, i.e., it contains at least one chemical linkage that is not a peptide bond. Thus, polypeptide derivatives include without limitation proteins that naturally undergo post-translational modifications such as, e.g., glycosylation. It is understood that a polypeptide of the invention may contain more than one of the following modifications within the same polypeptide. Preferred polypeptide derivatives retain a desirable attribute, which may be biological activity; more preferably, a polypeptide derivative is enhanced with regard to one or more desirable attributes, or has one or more desirable attributes not found in the parent polypeptide. Although they are described in this section, peptidomimetics are taken as small molecules in the present disclosure.[0993]
• XXI.C. Mutant Polypeptide Derivatives[0994]
• A polypeptide having an amino acid sequence identical to that found in a protein prepared from a natural source is a “wildtype” polypeptide. Mutant oligopeptides can be prepared by chemical synthesis, including without limitation combinatorial synthesis.[0995]
• Mutant polypeptides larger than oligopeptides can be prepared using recombinant DNA technology by altering the nucleotide sequence of a nucleic acid encoding a polypeptide. Although some alterations in the nucleotide sequence will not alter the amino acid sequence of the polypeptide encoded thereby (“silent” mutations), many will result in a polypeptide having an altered amino acid sequence that is altered relative to the parent sequence. Such altered amino acid sequences may comprise substitutions, deletions and additions of amino acids, with the proviso that such amino acids are naturally occurring amino acids.[0996]
• Thus, subjecting a nucleic acid that encodes a polypeptide to mutagenesis is one technique that can be used to prepare mutant polypeptides, particularly ones having substitutions of amino acids but no deletions or insertions thereof. A variety of mutagenic techniques are known that can be used in vitro or in vivo including without limitation chemical mutagenesis and PCR-mediated mutagenesis. Such mutagenesis may be randomly targeted (i.e., mutations may occur anywhere within the nucleic acid) or directed to a section of the nucleic acid that encodes a stretch of amino acids of particular interest. Using such techniques, it is possible to prepare randomized, combinatorial or focused compound libraries, pools and mixtures.[0997]
• Polypeptides having deletions or insertions of naturally occurring amino acids may be synthetic oligopeptides that result from the chemical synthesis of amino acid sequences that are based on the amino acid sequence of a parent polypeptide but which have one or more amino acids inserted or deleted relative to the sequence of the parent polypeptide. Insertions and deletions of amino acid residues in polypeptides having longer amino acid sequences may be prepared by directed mutagenesis.[0998]
• XXI.D. Chemically Modified Polypeptides[0999]
• As contemplated by this invention, the term “polypeptide” includes those having one or more chemical modification relative to another polypeptide, i.e., chemically modified polypeptides. The polypeptide from which a chemically modified polypeptide is derived may be a wildtype protein, a mutant protein or a mutant polypeptide, or polypeptide fragments thereof; an antibody or other polypeptide ligand according to the invention including without limitation single-chain antibodies, bacterial proteins and polypeptide derivatives thereof; or polypeptide ligands prepared according to the disclosure. Preferably, the chemical modification(s) confer(s) or improve(s) desirable attributes of the polypeptide but does not substantially alter or compromise the biological activity thereof. Desirable attributes include but are limited to increased shelf-life; enhanced serum or other in vivo stability; resistance to proteases; and the like. Such modifications include by way of non-limiting example N-terminal acetylation, glycosylation, and biotinylation.[1000]
• XXI.D.1. Polypeptides with N-Terminal or C-Terminal Chemical Groups[1001]
• An effective approach to confer resistance to peptidases acting on the N-terminal or C-terminal residues of a polypeptide is to add chemical groups at the polypeptide termini, such that the modified polypeptide is no longer a substrate for the peptidase. One such chemical modification is glycosylation of the polypeptides at either or both termini. Certain chemical modifications, in particular N-terminal glycosylation, have been shown to increase the stability of polypeptides in human serum (Powell et al. (1993), Pharma. Res. 10: 1268-1273). Other chemical modifications which enhance serum stability include, but are not limited to, the addition of an N-terminal alkyl group, consisting of a lower alkyl of from 1 to 20 carbons, such as an acetyl group, and/or the addition of a C-terminal amide or substituted amide group.[1002]
• XXI.D.2. Polypeptides with a Terminal D-Amino Acid[1003]
• The presence of an N-terminal D-amino acid increases the serum stability of a polypeptide that otherwise contains L-amino acids, because exopeptidases acting on the N-terminal residue cannot utilize a D-amino acid as a substrate. Similarly, the presence of a C-terminal D-amino acid also stabilizes a polypeptide, because serum exopeptidases acting on the C-terminal residue cannot utilize a D-amino acid as a substrate. With the exception of these terminal modifications, the amino acid sequences of polypeptides with N-terminal and/or C-terminal D-amino acids are usually identical to the sequences of the parent L-amino acid polypeptide.[1004]
• XXI.D.3. Polypeptides With Substitution of Natural Amino Acids By Unnatural Amino Acids[1005]
• Substitution of unnatural amino acids for natural amino acids in a subsequence of a polypeptide can confer or enhance desirable attributes including biological activity. Such a substitution can, for example, confer resistance to proteolysis by exopeptidases acting on the N-terminus. The synthesis of polypeptides with unnatural amino acids is routine and known in the art (see, for example, Coller, et al. (1993), cited above).[1006]
• XXI.D.4. Post-Translational Chemical Modifications[1007]
• Different host cells will contain different post-translational modification mechanisms that may provide particular types of post-translational modification of a fusion protein if the amino acid sequences required for such modifications is present in the fusion protein. A large number (˜100) of post-translational modifications have been described, a few of which are discussed herein. One skilled in the art will be able to choose appropriate host cells, and design chimeric genes that encode protein members comprising the amino acid sequence needed for a particular type of modification.[1008]
• Glycosylation is one type of post-translational chemical modification that occurs in many eukaryotic systems, and may influence the activity, stability, pharmacogenetics, immunogenicity and/or antigenicity of proteins. However, specific amino acids must be present at such sites to recruit the appropriate glycosylation machinery, and not all host cells have the appropriate molecular machinery.[1009]Saccharomyces cerevisieaeandPichia pastorisprovide for the production of glycosylated proteins, as do expression systems that utilize insect cells, although the pattern of glyscoylation may vary depending on which host cells are used to produce the fusion protein.
• Another type of post-translation modification is the phosphorylation of a free hydroxyl group of the side chain of one or more Ser, Thr or Tyr residues. Protein kinases catalyze such reactions. Phosphorylation is often reversible due to the action of a protein phosphatase, an enzyme that catalyzes the dephosphorylation of amino acid residues.[1010]
• Differences in the chemical structure of amino terminal residues result from different host cells, each of which may have a different chemical version of the methionine residue encoded by a start codon, and these will result in amino termini with different chemical modifications.[1011]
• For example, many or most bacterial proteins are synthesized with an amino terminal amino acid that is a modified form of methionine, i.e, N-formyl-methionine (fMet). Although the statement is often made that all bacterial proteins are synthesized with an fMet initiator amino acid; although this may be true for[1012]E. coli,recent studies have shown that it is not true in the case of other bacteria such asPseudomonas aeruginosa(Newton et al., J. Biol. Chem. 274:22143-22146, 1999). In any event, inE. coli,the formyl group of fMet is usually enzymatically removed after translation to yield an amino terminal methionine residue, although the entire fMet residue is sometimes removed (see Hershey, Chapter 40, “Protein Synthesis” in:Escherichia ColiandSalmonella Typhimurium:Cellular and Molecular Biology, Neidhardt, Frederick C., Editor in Chief, American Society for Microbiology, Washington, D.C., 1987,Volume 1, pages 613-647, and references cited therein.)E. colimutants that lack the enzymes (such as, e.g., formylase) that catalyze such post-translational modifications will produce proteins having an amino terminal fMet residue (Guillon et al., J. Bacteriol. 174:4294-4301, 1992).
• In eukaryotes, acetylation of the initiator methionine residue, or the penultimate residue if the initiator methionine has been removed, typically occurs co- or post-translationally. The acetylation reactions are catalyzed by N-terminal acetyltransferases (NATs, a.k.a. N-alpha-acetyltransferases), whereas removal of the initiator methionine residue is catalyzed by methionine aminopeptidases (for reviews, see Bradshaw et al., Trends Biochem. Sci. 23:263-267, 1998; and Driessen et al., CRC Crit. Rev. Biochem. 18:281-325, 1985). Amino terminally acetylated proteins are said to be “N-acetylated,” “N alpha acetylated” or simply “acetylated.”[1013]
• Another post-translational process that occurs in eukaryotes is the alpha-amidation of the carboxy terminus. For reviews, see Eipper et al. Annu. Rev. Physiol. 50:333-344, 1988, and Bradbury et al. Lung Cancer 14:239-251, 1996. About 50% of known endocrine and neuroendocrine peptide hormones are alpha-amidated (Treston et al., Cell Growth Differ. 4:911-920, 1993). In most cases, carboxy alpha-amidation is required to activate these peptide hormones.[1014]
• XXI.E. Peptidomimetics[1015]
• In general, a polypeptide mimetic (“peptidomimetic”) is a molecule that mimics the biological activity of a polypeptide but is no longer peptidic in chemical nature. By strict definition, a peptidomimetic is a molecule that contains no peptide bonds (that is, amide bonds between amino acids). However, the term peptidomimetic is sometimes used to describe molecules that are no longer completely peptidic in nature, such as pseudo-peptides, semi-peptides and peptoids. Examples of some peptidomimetics by the broader definition (where part of a polypeptide is replaced by a structure lacking peptide bonds) are described below. Whether completely or partially non-peptide, peptidomimetics according to this invention provide a spatial arrangement of reactive chemical moieties that closely resembles the three-dimensional arrangement of active groups in the polypeptide on which the peptidomimetic is based. As a result of this similar active-site geometry, the peptidomimetic has effects on biological systems that are similar to the biological activity of the polypeptide.[1016]
• There are several potential advantages for using a mimetic of a given polypeptide rather than the polypeptide itself. For example, polypeptides may exhibit two undesirable attributes, i.e., poor bioavailability and short duration of action. Peptidomimetics are often small enough to be both orally active and to have a long duration of action. There are also problems associated with stability, storage and immunoreactivity for polypeptides that are not experienced with peptidomimetics.[1017]
• Candidate, lead and other polypeptides having a desired biological activity can be used in the development of peptidomimetics with similar biological activities. Techniques of developing peptidomimetics from polypeptides are known. Peptide bonds can be replaced by non-peptide bonds that allow the peptidomimetic to adopt a similar structure, and therefore biological activity, to the original polypeptide. Further modifications can also be made by replacing chemical groups of the amino acids with other chemical groups of similar structure. The development of peptidomimetics can be aided by determining the tertiary structure of the original polypeptide, either free or bound to a ligand, by NMR spectroscopy, crystallography and/or computer-aided molecular modeling. These techniques aid in the development of novel compositions of higher potency and/or greater bioavailability and/or greater stability than the original polypeptide (Dean (1994), BioEssays, 16: 683-687; Cohen and Shatzmiller (1993), J. Mol. Graph., 11: 166-173; Wiley and Rich (1993), Med. Res. Rev., 13: 327-384; Moore (1994), Trends Pharmacol. Sci., 15: 124-129; Hruby (1993), Biopolymers, 33: 1073-1082; Bugg et al. (1993), Sci. Am., 269: 92-98, all incorporated herein by reference].[1018]
• Thus, through use of the methods described above, the present invention provides compounds exhibiting enhanced therapeutic activity in comparison to the polypeptides described above. The peptidomimetic compounds obtained by the above methods, having the biological activity of the above named polypeptides and similar three-dimensional structure, are encompassed by this invention. It will be readily apparent to one skilled in the art that a peptidomimetic can be generated from any of the modified polypeptides described in the previous section or from a polypeptide bearing more than one of the modifications described from the previous section. It will furthermore be apparent that the peptidomimetics of this invention can be further used for the development of even more potent non-peptidic compounds, in addition to their utility as therapeutic compounds.[1019]
• Specific examples of peptidomimetics derived from the polypeptides described in the previous section are presented below. These examples are illustrative and not limiting in terms of the other or additional modifications.[1020]
• XXI.E.1. Peptides With A Reduced Isostere Pseudopeptide Bond[1021]
• Proteases act on peptide bonds. It therefore follows that substitution of peptide bonds by pseudopeptide bonds confers resistance to proteolysis. A number of pseudopeptide bonds have been described that in general do not affect polypeptide structure and biological activity. The reduced isostere pseudopeptide bond is a suitable pseudopeptide bond that is known to enhance stability to enzymatic cleavage with no or little loss of biological activity (Couder, et al. (1993), Int. J. Polypeptide Protein Res. 41:181-184, incorporated herein by reference). Thus, the amino acid sequences of these compounds may be identical to the sequences of their parent L-amino acid polypeptides, except that one or more of the peptide bonds are replaced by an isostere pseudopeptide bond. Preferably the most N-terminal peptide bond is substituted, since such a substitution would confer resistance to proteolysis by exopeptidases acting on the N-terminus.[1022]
• XXI.E.2. Peptides With A Retro-Inverso Pseudopeptide Bond[1023]
• To confer resistance to proteolysis, peptide bonds may also be substituted by retro-inverso pseudopeptide bonds (Dalpozzo, et al. (1993), Int. J. Polypeptide Protein Res. 41:561-566, incorporated herein by reference). According to this modification, the amino acid sequences of the compounds may be identical to the sequences of their L-amino acid parent polypeptides, except that one or more of the peptide bonds are replaced by a retro-inverso pseudopeptide bond. Preferably the most N-terminal peptide bond is substituted, since such a substitution will confer resistance to proteolysis by exopeptidases acting on the N-terminus.[1024]
• XXI.E.3. Peptoid Derivatives[1025]
• Peptoid derivatives of polypeptides represent another form of modified polypeptides that retain the important structural determinants for biological activity, yet eliminate the peptide bonds, thereby conferring resistance to proteolysis (Simon, et al., 1992, Proc. Natl. Acad. Sci. USA, 89:9367-9371 and incorporated herein by reference). Peptoids are oligomers of N-substituted glycines. A number of N-alkyl groups have been described, each corresponding to the side chain of a natural amino acid.[1026]
• XXII. KITS[1027]
• The invention provides for diagnostic and therapeutic kits related useful for therapeutic, diagnostic, and research applications. Exemplary kits are disclosed in U.S. Pat. Nos. 5,773,024; 6,017,721; and 6,232,127 B1. The kits of the invention incorporate minicells, and/or include methods of using minicells described herein.[1028]
• XXII.A. Diagnostic and Research Use Kit Components[1029]
• In one embodiment, the invention relates to kits for determining the diagnosis or prognosis of a patient. These kits preferably comprise devices and reagents for measuring one or more marker levels in a test sample from a patient, and instructions for performing the assay. Optionally, the kits may contain one or more means for converting marker level(s) to a prognosis. Such kits preferably contain sufficient reagents to perform one or more such determinations.[1030]
• More specifically, a diagnostic kit of the invention comprises any of the following reagents and/or components in any combination.[1031]
• (1) A detectable or detectably labeled first reagent that binds a ligand of interest. The binding reagent can, but need not, be an antibody or an antibody derivative comprising a detectable moiety. The sphingolipid-binding reagent is stored in an openable container in the kit, or is bound to a surface of a substrate such that it is accessible to other reagents. Examples of the latter include test strips.[1032]
• (2) If the first reagent in neither detectable nor detectably labeled, the kit may comprise a detectable or detectably labeled second reagent that binds to the first reagent (e.g., a secondary antibody) or which produces a detectable signal when in close proximity to the first reagent (e.g., as results from fluorescent resonance energy transfer FRET). In either case, the signal produced from the second reagent correlates with the amount of ligand in the sample.[1033]
• (3) One or more positive control reagents. Typically, these reagents comprise a compound that is known to produce a signal in the assay. In one embodiment, the positive control reagents are standards, i.e., comprise a known amount of a detectable or detectably labeled compound, the signal from which may be compared to the signal from a test sample. In addition to serving as positive control reagents, they may be used to develop calibration curves that relate the amount of signal to the known concentration of a detectable or detectably labeled compound. The signal from a test sample is compared to the calibration curve in order to determine what concentration of the detectable or detectably labeled compound corresponds to the signal from the test sample. In this embodiment, the kit provides quantitative measurements of the amount of a ligand in a test sample.[1034]
• (4) One or more negative control reagents. Typically, these control reagents may comprise buffer or another solution that does not contain any of the detectable or detectably labeled first or second reagents and should thus not produce any detectable signal. Any signal that is detected reflects the background level of “noise” in the assay. Another type of negative control reagent contains most of the components necessary for the signal of the assay to be produced, but lacks at least one such component and therefor should not produce a signal. Yet another type of negative control reagent contains all of the components necessary for the signal of the assay to be produced, but also contains an inhibitor of the process that produced the signal.[1035]
• (5) One or more auxiliary reagents for use in the diagnostic assays of the kit, e.g., buffers, alcohols, acid solutions, etc. These reagents are generally available in medical facilities and thus are optional components of the kit. However, these reagents preferably are included in the kit to ensure that reagents of sufficient purity and sterility are used, since the resulting protein conjugates are to be administered to mammals, including humans, for medical purposes, and to provide kits that can be used in situations where medical facilities are not readily available, e.g., when hiking in places located far from medical facilities, or in situations where the presence of these auxiliary reagents allows for the immediate treatment of a patient outside of a medical facility as opposed to treatment that arrives at some later time).[1036]
• (6) Instructions to a person using a kit for its use. The instructions can be present on one or more of the kit components, the kit packaging and/or a kit package insert.XXII.B. Therapeutic Kit Components[1037]
• A therapeutic kit of the invention comprises any of the following reagents and/or components in any combination.[1038]
• (1) One or more therapeutic agents.[1039]
• (2) If the therapeutic agent(s) are not formulated for delivery via the alimentary canal, which includes but is not limited to sublingual delivery, a device capable of delivering the therapeutic agent through some other routes. One type of device for parenteral delivery is a syringe that is used to inject the therapeutic agent into the body of an animal in need of the therapeutic agent. Inhalation devices may also be used.[1040]
• (3) Separate containers, each of which comprises one or more reagents of the kit. In a preferred embodiment, the containers are vials contain sterile, lyophilized formulations of a therapeutic composition that are suitable for reconstitution. Other containers include, but are not limited to, a pouch, tray, box, tube, or the like. Kit components may be packaged and maintained sterilely within the containers.[1041]
• (4) Instructions to a person using a kit for its use. The instructions can be present on one or more of the kit components, the kit packaging and/or a kit package insert. Such instructions include, by way of non-limiting example, instructions for use of the kit and its reagents, for reconstituting lyophilized reagents or otherwise preparing reagents.[1042]
• A preferred kit of the present invention comprises the elements useful for performing an immunoassay. A kit of the present invention can comprise one or more experimental samples (i.e., formulations of the present invention) and one or more control samples bound to at least one pre-packed dipstick or ELISA plate, and the necessary means for detecting immunocomplex formation (e.g., labelled secondary antibodies or other binding compounds and any necessary solutions needed to resolve such labels, as described in detail above) between antibodies contained in the bodily fluid of the animal being tested and the proteins bound to the dipstick or ELISA plate. It is within the scope of the invention that the kit can comprise simply a formulation of the present invention and that the detecting means can be provided in another way.[1043]
• An alternative preferred kit of the present invention comprises elements useful for performing a skin test. A kit of the present invention can comprise at least one pre-packed syringe and needle apparatus containing one or more experimental samples and/or one or more control samples. A kit according to the invention may be designed for both diagnostic and therapeutiuc applications. Any combination of the above elements XX.A.(1)-(6) and XX.B.(1)-(4) may be used in a kit, optionally with additional reagents, standards, sample containers, an the like.[1044]
• XXIII. Immunogenic Minicells[1045]
• XXIII.A. In General[1046]
• Minicells are used to immunize subjects. An organism is said to be “immunized” when, after contact with an immunogen, the organism produces antibodies directed to the immunogen, or has increased proliferation or activity of cytotoxic and/or helper T cells, or both. Increased proliferation or activity of T cells may be particularly desirable in the case of parasites that cause a decrease in T cell proliferation.[1047]
• The use of minicells to present antigens has several potential advantages. An intact membrane protein can be presented in its native form on the surface of an immunogenic minicell, rather than as a denatured protein or as oligopeptides derived from the amino acid sequence of a membrane protein, which allows for antibodies to be developed that are directed to epitopes which, due to protein folding, occur only in the native protein. The minicell surface may naturally be, or may be modified to be, an adjuvant. Moreover, pharmacokinetic properties of minicells, as discussed elsewhere herein, may be improved relative to other forms of administration.[1048]
• The applications of immunogenic minicells include, but are not limited to, research, prophylactic, diagnostic and therapeutic applications.[1049]
• In research applications, immunogenic minicells are used to generate antibodies to an antigen displayed on a minicell. Such antibodies are used to detect an antigen, which may be a chemical moiety, molecule, virus, organelle, cell, tissue, organ, or organism that one wishes to study. Classically, such antibodies have been prepared by immunizing an animal, often a rat or a rabbit, and collecting antisera therefrom. Molecular biology techniques can be used to prepare antibodies and antibody fragments, as is described elsewhere herein. Single-chain antibody fragments (scFv) may also be identified, purified, and characterized using minicells displaying a membrane protein or membrane bound chimeric soluble protein.[1050]
• In prophylactic applications, immunogenic minicells are used to stimulate a subject to produce antibodies and/or activate T cells, so that the subject is “pre-immunized” before contact with a pathogen or hyperproliferative cell. Thus, in the case of a pathogens, the subject is protected by antibodies and/or T cells that are specifically directed to the pathogen before infection.[1051]
• In therapeutic applications, immunogenic minicells are used in immunotherapy.[1052]
• Certain aspects of the invention involve active immunotherapy, in which treatment relies on the in vivo stimulation of the endogenous host immune system to react against pathogens or tumors due to the administration of agents that cause, enhance or modulate an immune response. Such agents include, but are not limited to, immunogens, adjuvants, cytokines and chemokines.[1053]
• Other therapeutic applications involve passive immunotherapy, in which treatment involves the delivery of agents (such as antibodies or effector cells) that are specifically directed to an immunogen of a pathogen or a hyperproliferative cell, and does not necessarily depend on an intact host immune system. Examples of effector cells include T cells; T lymphocytes, such as CD8+ cytotoxic T lymphocytes and CD4+ T-helper tumor-infiltrating lymphocytes; killer cells, such as Natural Killer (NK) cells and lymphokine-activated killer cells.[1054]
• XXIII.B. Hyperproliferative Disorders[1055]
• The immunogenic minicells of the invention can be used to treat hyperproliferative disorders by inducing an immune response to an antigen associated therewith. The term “hyperproliferative disorder” refers to disorders characterized by an abnormal or pathological proliferation of cells, for example, cancer, psoriasis, hyperplasia and the like.[1056]
• For reviews of immunotherapy as applied to hyperproliferative disorders, see Armstrong et al., Cellular immunotherapy for cancer, BMJ 323:1289-1293, 2001; Evans, Vaccine therapy for cancer—fact or fiction?, Proc R Cell Physicians Edinb 31:9-16, 2001; Ravindranath and Morton, “Active Specific Immunotherapy with Vaccines,” Chapter 61 in: Holland-Frei Cancer Medicine, Fifth Edition, Bast, Robert C., et al., editors, B. C. Decker, Inc., Hamilton, 2000, pages 800-814.[1057]
• Types of cancers include without limitation fibrosarcoma, myxosarcoma, liposarcoma, chondrosarcoma, osteogenic sarcoma, chordoma, angiosarcoma, endotheliosarcoma, lymphangiosarcoma, lymphangioendotheliosarcoma, synovioma, mesothelioma, Ewing's tumor, leiomyosarcoma, rhabdomyosarcoma, colon carcinoma, pancreatic cancer, breast cancer, ovarian cancer, prostate cancer, squamous cell carcinoma, basal cell carcinoma, adenocarcinoma, sweat gland carcinoma, sebaceous gland carcinoma, papillary carcinoma, papillary adenocarcinomas, cystadenocarcinoma, medullary carcinoma, bronchogenic carcinoma, renal cell carcinoma, hepatoma, bile duct carcinoma, choriocarcinoma, seminoma, embryonal carcinoma, Wilms' tumor, cervical cancer, testicular tumor, lung carcinoma, small cell lung carcinoma, bladder carcinoma, epithelial carcinoma, glioma, astrocytoma, medulloblastoma, craniopharyngioma, ependymoma, pinealoma, hemangioblastoma, acoustic neuroma, oligodendroglioma, meningioma, melanoma, neuroblastoma, retinoblastoma, leukemia, lymphoma, multiple myeloma, Waldenstrom's macroglobulinemia, and heavy chain disease.[1058]
• Tumor specific antigens (TSAs), tumor-associated differentiation antigens (TADAs) and other antigens associated with cancers and other hyperproliferative disorders include, but are not limited to, C1 IAC, a human cancer associated protein (Osther, U.S. Pat. No. 4,132,769); the CA125 antigen, an antigen associated with cystadenocarcinoma of the ovary, (Hanisch et al., Carbohydr. Res. 178:29-47, 1988; O'Brien, U.S. Pat. No. 4,921,790); CEA, an antigen present on many adenocarcinomas (Horig et al., Strategies for cancer therapy using carcinembryonic antigen vaccines, Expert Reviews in Molecular Medicine, http://www-ermm.cbcu.cam.ac.uk: 1, 2000); CORA (carcinoma or orosomucoid-related antigen) described by Toth et al. (U.S. Pat. No. 4,914,021); DF3 antigen from human breast carcinoma (Kufe, in U.S. Pat. Nos. 4,963,484 and 5,053,489); DU-PAN-2, a pancreatic carcinoma antigen (Lan et al., Cancer Res. 45:305-310, 1985); HCA, a human carcinoma antigen (Codington et al., U.S. Pat. No. 5,693,763); Her2, a breast cancer antigen (Fendly et al., The Extracellular Domain of HER2/neu Is a Potential Immunogen for Active Specific Immunotherapy of Breast Cancer, Journal of Biological Response Modifiers 9:449-455, 1990); MSA, a breast carcinoma glycoprotein (Tjandra et al., Br. J. Surg. 75:811-817, 1988); MFGM, a breast carcinoma antigen (Ishida et al., Tumor Biol. 10:12-22, 1989); PSA, prostrate specific antigen (Nadji et al., Prostatic-specific-antigen, Cancer 48:1229-1232, 1981); STEAP (six transmembrane epithelial antigens of the prostate) proteins (Afar et al., U.S. Pat. No. 6,329,503); TAG-72, a breast carcinoma glycoprotein (Kjeldsen et al., Cancer Res. 48:2214-2220, 1988); YH206, a lung carcinoma antigen (Hinoda et al., Cancer J. 42:653-658, 1988); the p97 antigen of human melanoma (Estin et al., Recombinant Vaccinia Virus Vaccine Against the Human Melanoma Antigen p97 for Use in Immunotherapy, Proc. Natl Acad. Sci. USA, 85:1052-1056, 1988); and the melanoma specific antigen described by Pfreundschuh in U.S. Pat. No. 6,025,191);[1059]
• XXIII.B. Intracellular Pathogens[1060]
• In certain aspects of the invention, vaccines comprising immunogenic minicells are used to prevent or treat diseases caused by intracellular pathogens. Vaccines may be prepared that stimulate cytotoxic T cell responses against cells infected with viruses including, but not limited to, hepatitis type A, hepatitis type B, hepatitis type C, influenza, varicella, adenovirus, herpes simplex type I (HSV-I), herpes simplex type II (HSV-II), rinderpest, rhinovirous, echovirus, rotavirus, respiratory syncytial virus, papilloma virus, papova virus, cytomegalovirus, echinovirus, arbovirus, huntavirus, coxsackie virus, mumps virus, measles virus, rubella virus, polio virus, human immunodeficiency virus type I (HIV-I), and human immunodeficiency virus type II (HIV-II). Vaccines also may be prepared that stimulate cytotoxic T cell responses against cells infected with intracellular obligates, including but not limited to Chlamydia, Mycobacteria and Rickettsia. Vaccines also may be prepared that stimulate cytotoxic T cell responses against cells infected with intracellular protozoa, including, but not limited to, leishmania, kokzidioa, and trypanosoma.[1061]
• The causative agent of Lyme disease, the spirochete[1062]Borrelia burgdorfei,is also of interest. The outer surface proteins (Osps) A, B and C ofB. burgdorfeiare known antigens that are lipoproteins that associate with membranes. Amino-terminal cysteine residues in Osp proteins are the sites of triacyl lipid modifications that serve as membrane-anchoring moities. The N-terminal portions of the Osp proteins are highly conserved and are preferred portions for display on immunogenic minicells.
• XXIII.C. Eukaryotic Pathogens[1063]
• In addition to intracellular pathogens, other eukaryotic pathogens exist and may also be treated using immunogenic minicells displayed antigens therefrom. A number of antigens have been used to develop anti-parasitic vaccines, e.g. the recombinant 45w protein of Taenia ovis; EG95 oncosphere proteins of[1064]Echinococcus granulosis;cathepsin L antigen of the liver fluke,Fasciola hepatica;and the antigen ofHaemonchus contortus(Dalton et al., Parasite vaccines—a reality?, Vet Parasitol 98:149-167, 2001). Other eukaryotic pathogens include, but are not limited to:
• Protozoans, including but not limited to,[1065]Entamoeba histolytica,a pathogenic amoeba that causes amoebic dysentery and occasionally digests its way through the intestinal wall to invades other organs, which may cause morbidity;Balantinium coli,a ciliate that causes diarrhea in humans;Giardia lamblia,a flagellate that causes diarrhea and abdominal pain, along with a chronic fatigue syndrome that is otherwise asymptomatic and difficult to diagnose;Trypanosoma brucei,a hemoflagellate causing sleeping sickness; andTrypanosoma cruzi,the cause of Chagas disease);
• Plasmodia, sporozoan obligate intracellular parasites of liver and red blood cells, including but not limited to[1066]P. falciparum,the causative agent of malaria. Dozens ofP. falciparumantigens have been identified, e.g., CSP-1, STARP, SALSA, SSP-2, LSA-1, EXP-1, LSA-3, RAP-1, RAP-2, SERA-1, MSP-1, MSP-2, MSP-3, MSP-4, MSP-5, AMA-1, EBA-175, RESA, GLURP, EMP-1, Pfs25, Pfg27, Pf35, Pf55, Pfs230, Pfg27, Pfs16, Pfs28 and Pfs45/48.
• Helminthes including but not limited to[1067]Ascaris lumbricoides(roundworm);Enterobius vermicularis(pinworm);Trichuris trichiuria(whipworm); andFasciola hepatica(liver fluke);
• Taenia sp. (tapeworms and cestodes);[1068]
• Schistosoma (trematodes), such as[1069]Schistoma mansoni,which comprises the Sm32 antigen (asparaginyl endopeptidase), which can induce antibody formation in mice (Chlichlia et al., DNA vaccination with asparaginyl endopeptidase (Sm32) from the parasiteSchistosoma mansoni:anti-fecundity effect induced in mice, Vaccine 20:439-447, 2001); and acetylcholinesterase (Arnon et al., Acetylcholinesterase ofSchistoma mansoni-Functional correlates, Protein Science 8:2553-2561, 1999); and
• Ticks and other invertebrates, including but not limited to insects, arachnids, etc. For example, a description of a vaccine against the cattle tick Boophilus microplus has been described (Valle et al., The evaluation of yeast derivatives as adjuvants for the immune response to the Bm86 antigen in cattle, BMC Biotechnol. 1:2, 2001)[1070]
• XXIII.D. Formulation and Adminstration of Immunogenic Minicells[1071]
• Vaccine formulations of immunogenic minicells include a suitable carrier. Because minicells may be destroyed by digestion, or prevented from acting due to antibody secretion in the gvut, they are preferably administered parenterally, including, for example, administration that is subcutaneous, intramuscular, intravenous, or intradermal. Formulations suitable for parenteral administration include aqueous and non-aqueous sterile injection solutions which may contain antioxidanits, buffers, and solutes which render the formulation isotonic with the bodily fluid, preferably the blood, of the individual; and aqueous and non-aqueous sterile suspensions which may include suspending agents or thickening agents. The formulations may be presented in unit-dose or multi-dose containers, for example, sealed ampules and vials and may be stored in a freeze-dried condition requiring only the addition of the sterile liquid carrier immediately prior to use. The vaccine formulation may also include adjuvant systems for enhancing the immunogenicity of the formulation. Adjuvants are substances that can be used to augment a specific immune response. Normally, the adjuvant and the composition are mixed prior to presentation to the immune system, or presented separately, but into the same site of the mammal being immunized. Examples of materials suitable for use in vaccine compositions are provided in Osol, A., ed., Remington's Pharmaceutical Sciences, Mack Publishing Co, Easton, Pa. (1980), pp. 1324-1341, which reference is entirely incorporated herein by reference.[1072]
• Compositions comprising immunogenic minicells are injected into a human or animal at a dosage of 1-1000 ug per kg body weight. Antibody titers against growth factor are determined by ELISA, using the recombinant protein and horseradish peroxidase-conjugated goat anti-human or animal immunoglobulins or other serologic techniques (e.g., sandwich ELISA). Booster injections are administered as needed to achieve the desired levels of protective antibodies and/or T cells.[1073]
• Routes and frequency of administration, as well as dosage, will vary from individual to individual. Between 1 and 10 doses may be administered for a 52-week period. Preferably, 6 doses are administered, at intervals of 1 month, and booster vaccinations may be given periodically thereafter. Alternate protocols may be appropriate for individual patients. In immunotherapy of hyperproliferative disorders, a suitable dose is an amount of a compound that, when administered as described above, is capable of promoting an anti-tumor immune response. Such response can be monitored by measuring the anti-tumor antibodies in a patient or by vaccine-dependent generation of cytolytic effector cells capable of killing the patient's tumor cells in vitro. Such vaccines should also be capable of causing an immune response that leads to an improved clinical outcome (e.g., more frequent remissions, complete or partial or longer disease-free survival) in vaccinated patients as compared to non-vaccinated patients.[1074]
• The vaccine according to the invention may contain a single species of immunogenic minicells according to the invention or a variety of immunogenic minicells, each of which displays a different immunogen. Additionally or alternatively, immunogenic minicells may each display and/or express more than one immunogen.[1075]
• The summary of the invention described above is non-limiting and other features and advantages of the invention will be apparent from the following detailed description of the invention, and from the claims.[1076]
EXAMPLESExample 1Creation of a Minicell-Producing Bacterial Cell Line (MC-T7) that Expresses an Exogenous RNA Polymerase
• In order to maximize the amount of RNA transcription from episomal elements in minicells, a minicell-producing cell line that expresses an RNA polymerase specific for certain episomal expression elements was created. This[1077]E. colistrain, designated MC-T7, was created as follows.
• The P678-54[1078]E. colistrain contains mutations that influence cell division and induce the production of minicells (Adler et al., Proc. Natl. Acad. Sci. 57:321-326 (1967), Allen et al., Biochem. Biophys. Res. Communi. 47:1074-1079 (1972), Hollenberg et al., Gene 1:33-47 (1976)). The P678-54 strain is resistant to Lambda phage due to a mutation in the malT gene (Gottesman, Bacteriophage Lambda: The Untold Story. J. Mol. Biol. 293:177-180, 1999; Friedman, Interactions Between Bacteriophage Lambda and itsEscherichia ColiHost. Curr. Opin. Genet. Dev. 2:727-738, 1992). Thus, as an initial step, the P678-54 strain was altered so as to be sensitive to Lambda phage so that it could form lysogens of Lambda-DE3 (see below). Wildtype MalT-encoding sequences were restored via a HFR (high frequency recombination) conjugation protocol using the G43E. colistrain (CGSC stain 4928).
• Recipient (P678-54) and donor (G43:BW6169) strains were grown overnight in 10 mL of LB media (10 g NaCl, 10 g select peptone 140, and 5 g yeast extract in one liter ddH[1079]₂0). The samples were centrifuged and then concentrated in about 0.2 mL of LB media. The concentrated samples were combined and incubated with slow rotation for 30 minutes at 30° C., and were then plated on LB agar plates that contained streptomycin (50 μg/mL) and tetracycline (50 μg/mL). (Ampicillin, streptomycin, tetracycline, and all other chemicals were purchased from Sigma Chemical (St. Louis, Mo.) unless otherwise indicated.) Recipient cells were resistant to streptomycin and donor cells were resistant to tetracycline; only conjugates, which contained both resistance genes, were able to grow on the LB agar plates that contained streptomycin (50 μg/mL) and tetracycline (50 μg/mL).
• Putative conjugates were screened for Lambda phage sensitivity using a cross streak technique, in which putative colonies were cross-streaked on an LB agarose plate (streptomycin, 50 μg/mL, and tetracycline, 50 μg/mL) that had been streaked with live Lambda phage. The streaked conjugate colonies were streaked perpendicular to the Lambda phage streak; if a conjugate was sensitive to Lambda phage infection then, upon contact with the Lambda phage streak, there was cell lysis and thus less or no bacterial growth. Thus, in the case of conjugates that were sensitive to Lambda phage, there was deceased bacterial growth “downstreak” from the phage streak.[1080]
• The conjugate[1081]E. colithat were found to be sensitive to Lambda phage infection were then used to create Lambda lysogens. Lysogenization is a process during which Lambda phage incorporates its genome, including exogenous genes added thereto, into a specific site on the chromosome of itsE. colihost cell.
• The DE3 gene, which is present in the genome of the Lamda phage used to create lysogens, encodes RNA polymerase from bacteriophage T7. Lysogenation was carried out using the DE3-Lysogenation kit (Novagen, Madison, Wis.) essentially according to the manufacturer's instructions. A T7 polymerase dependent tester phage was used to confirm the presence and expression of the DE3 gene on the bacterial chromosome. The T7-dependent tester phage can only form plaques on a baterial known in the presence of T7 polymerase. The phage uses a T7 promoter for expression of its essential genes. Therefore in a plaque-forming assay only cells which express T7 polymerase can be lysed by the tester phage and only these cells will allow for the formation of plaques. As is described in more detail herein, episomal expression elements that are used in minicells may be designed such that transcription and translation of a cloned gene is driven by T7 RNA polymerase by utilizing expression sequences specific for the T7 RNA polymerase.[1082]
Example 2Cloning of Rat Edg-1 into the pCAL-c Expression Vector
• Materials[1083]
• Taq Polymerase, PCR Buffers, and PCR reagents were purchased from Roche Molecular Biochemicals (Indianapolis, Ind.) All restriction enzymes were purchased from Gibco BRL (Grand Island, N.Y.) and Stratagene (La Jolla, Calif.). QIAprep mini and maxi kits, PCR purification Kits, RNeasy miniprep kits, and the One Step RT-PCR Kit were purchased from QIAGEN (Valencia, Calif.). The Geneclean Kit was purchased from BIO 101 (Carlsbad, Calif.). IPTG (isopropy-beta-D-thiogalactopyranoside), T4 DNA Ligase, LB Media components and agarose were purchased from Gibco BRL. The pCAL-c prokaryote expression vector and competent cells were purchased from Stratagene.[1084]
• The pCAL-c expression vector has a structure in which an ORF may be operably linked to a high-level (but T7 RNA polymerase dependent) promoter, sequences that bind the[1085]E. coliLac repressor, and the strong T7 gene 10 ribosome-binding site (RBS). The LacI repressor is also encoded by an expressed from te pCAL-c vector. As long as it is bound to its recognition sequences in the pCAL-c expression element, the lac repressor blocks transcription from the T7 promoter. When an inducing agent, such as IPTG is added, the lac repressor is released from its binding sites and transcription proceeds from the T7 protmoter, provided the T7 RNA polymerase is present. After induction, the cloned and expressed protein may constitute the majority of newley expressed cellular proteins due to the efficient transcription and translation processes of the system.
• Amplification[1086]
• The first step in cloning rat Edg-1 (rEDG-1) into an expression vector was to design primers for amplification via PCR (polymerase chain reaction). PCR primers were designed using the rat Edg-1 sequence (Nakajima et al., Biophy, J. 78:319A, 2000) in such a manner that they contained either sites for NheI (GCTAGC) or BamHI (GGATCC) on their five prime ends. The upstream primer had the sequence of SEQ ID NO:31. The three prime downstream primer (SEQ ID NO:32) also contained a stop codon, as the pCAL-c vector contains a Calmodulin Binding Protein (CBP) “tag” at its carboxyl terminus which was not intended to be incorporated into the rat Edg-1 polypeptide in this expression construct. The primer and resulting PCR products were designed so that the five prime end of the rat Edg-1 ORF was in frame with the methionine start codon found in the pCAL-c vector.[1087]
• Oligonucleotide Primer Sequences for Cloning into pCAL-c:[1088]

  Edg1/pCAL-c construct primers:
  Upstream primer
  5′-AATTGCTAGCTCCACCAGCATCCCAGTGGTTA-3′	(SEQ ID NO:31)
  Downstream primer
  5′-AATTGGATCCTTAAGAAGAAGAATTGACGTTT-3′	(SEQ ID NO:32)
  Edg1/CBP fusion construct primers:
  Upstream primer
  5′-AATTGCTAGCTCCACCAGCATCCCAGTGGTTA-3′	(SEQ ID NO:31)
  Downstream primer
  5′-AATTGGATCCAGAACAAGAATTGACGTTTCCA-3′	(SEQ ID NO:33)
  Edg1/His6 construct primers:
  Upstream primer
  5′-AATTGCTAGCTCCACCAGCATCCCAGTGGTTA-3′	(SEQ ID NO:31)
  Downstream primer
  5′-AATTGGATCCTTAATGATGATGATGATGATGAGAAGAAGAATTGACGTTTCC-3′	(SEQ ID NO:34)
  Edg3/rtPCR primers:
  Upstream primer
  5′-TTATGGCAACCACGCACGCGCAGG-3′	(SEQ ID NO:35)
  Downstream primer
  5′-AGACCGTCACTTGCAGAGGAC-3′	(SEQ ID NO:36)
  Edg3/pCAL-c construct primers:
  Upstream primer
  5′-AATTGCTAGCACGCACGCGCAGGGGCACCCGC-3′	(SEQ ID NO:37)
  Downstream primer
  5′-AATTGGTACCTCACTTGCAGAGGACCCCATTCTG-3′	(SEQ ID NO:38)
  Edg3/His6 construct primers:
  Upstream primer
  5′-AATTGCTAGCACGCACGCGCAGGGGCACCCGC-3′	(SEQ ID NO:39)
  Downstream primer
  5′-AATTGGTACCTCAATGATGATGATGATGATGCTTGCAGAGGACCCCATTCTG-3′	(SEQ ID NO:16)
  GFP/pCAL-c construct primers:
  Upstream primer
  5′-GGTCGCCACCATGGTGAGCAA-3′	(SEQ ID NO:40)
  Downstream primer
  5′-TTAAGGATCCTTACTTGTACAGCTCGTCCAT-3′	(SEQ ID NO:41)
  GFP/CBP construct primers:
  Upstream primer
  5′-GGTCGCCACCATGGTGAGCAA-3′	(SEQ ID NO:42)
  Downstream primer
  5′-TTAAGGATCCCTTGTACAGCTCGTCCATGCC-3′	(SEQ ID NO:43)
  Notes:
  Restriction endonuclease sites are underlined
  Stop codons are double underlined

• The primers were used to amplify the rEdg-1 DNA ORF using the polymerase chain reaction (PCR). The template used for amplification was mRNA isolated from rat muscle tissue using the RNeasy Miniprep Kit (Qiagen) and was carried out essentially according to the manufacturer's protocol. Both the rtPCR and PCR amplification steps were carried out in a single reaction using the One Step RT-PCR Kit (Qiagen). The resulting rat Edg-1 PCR fragment was purified using the PCR Purification Kit (Qiagen). The amplified double stranded rEdg-1 DNA sequence contained the NheI site at the 5-prime end and the BamHI site at the 3-prime end. This amplified rEdg-1 fragment was used for cloning into the pCAL-c expression vector.[1089]
• The pCAL-c expression vector contains NcoI, NheI, and BamHI restriction sites in its multiple cloning site. In order to insert rEdg-1-encoding sequence into the expression vector, the rEdg-1 PCR fragment and the pCAL-c expression vector were digested with NheI and BamHI restriction enzymes for one hour at 37° C. The reaction mixture for the digestion step consisted of 1 μg of DNA, 1×restriction buffer, and 1 μL of each enzyme. The reaction mixture was brought to a final volume of 20 μL with ddH[1090]₂O (dd, double distilled). After 45 minutes, 1 μL of Calf Intestine Alkaline Phosphatase (CIAP) was added to the pCAL-c reaction mixture in order to remove the terminal phosphates from the digested plasmid DNA. The reactions were incubated for an additional 15 minutes at 37° C. The digested DNA samples were then run on a 1% TAE (Tris-acetate/EDTA electrophoresis buffer) agarose gel at 130 volts for 45 minutes. The bands were visualized with UV light after the gel was stained with ethidium bromide.
• The appropriate bands were cut out of the gel for purification using the Geneclean Kit (BIO101). The Purified DNA fragments were then quantified on a 1% TAE agarose gel. For the ligation reaction, ratios of insert to vector of 6:1 and 3:1 were used. A negative control comprising vector only was also included in the ligation reactions. The reaction mixtures contained insert and vector DNA, 4 μL Ligase buffer, and 2 μL Ligase. The reaction was brought up to a final volume of 20 μL with ddH[1091]₂O. The ligation was carried out at room temperature for about 2 hours. Ten (10) μL of the ligation reaction mixture was used for subsequent transformation steps.
• Ligated DNA was introduced into Epicurian[1092]ColiXL1-Blue competent cells using the heat shock transformation technique as follows. The ligation mixture was added to 100 μL of competent cells, placed on ice, and was incubated for about 30 minutes. The cells were then heat shocked at 37° C. for 1 minute and put back on ice for 2 minutes. Following heat shock, 950 μL of room temperature LB media was added to the cells and the cells were shaken at 37° C. for 1 hour. Following the 1-hour agitation the cells were pelleted for one minute at 12000 rpm in a Eppendorf 5417C microcentrifuge. The supernatant was carefully poured off so that about 200 μL remained. The cells were then resuspended in the remaining LB media and spread on 100×15 mm LB agarose plates containing 50 μg/mL ampicilin. The plates were incubated overnight at 37° C. Colonies were counted the following day, and the ratio of colonies between the negative control and the ligated samples was determined. A high ratio of the number of colonies when the ligation mixture was used to transform cells, as contrasted to the number of negative control colonies indicated that the cloning was successful. Transformed colonies were identified, isolated, and grown overnight in LB media in the presence of ampicillin. The resulting bacterial populations were screened for the presence of the Edg-1-pCAL-c expression construct.
• Plasmid DNA was isolated from the cells using the QIAprep Spin Miniprep Kit (Qiagen). Isolated Edg-1-pCAL-c constructs were screened using the restriction enzyme ApaI, which digests the Edg-1-pCAL-c construct at two different sites: one in the Edg-1 coding sequence and one in the pCAL-c vector itself. The plasmid preparations were digested with ApaI electrophoresed on a 1% TAE agarose gel and visualized using uv light and ethidium bromide staining. The predicted sizes of the expected DNA fragments were 2065 bp and 4913 bp. As shown in FIG. 3, bands of the predicted size were present on the gel. The entire Edg-1-pCAL-c construct was sequenced in order to confirm its structure. This expression construct, a pCAL-c derivative that contains the rat Edg-1 ORF operably linked to a T7 promoter and lac repressor binding sites, is designated “prEDG-1” herein.[1093]
Example 3Construction of Rat Edg-1-CBP Fusion Protein
• In order to detect rat Edg-1 protein expression, rEdg-1 coding sequences were cloned into the pCAL-c vector in frame with a CBP fusion tag. The cloning strategy for the rEdg-1-CBP construct was performed essentially as described for the Edg-1-pCAL-c construct with the following differences. The PCR primers (SEQ ID NOS:3 and 5) were as described for the Edg-1-pCAL-c cloning except for the omission of the stop codon in the downstream primer (SEQ ID NO:33). The removal of the stop codon is required for the construction of the Edg-1-CBP fusion protein. The pCAL-c vector is designed so that, when the BamHI site is used for insertional cloning, and no stop codon is present in an ORF inserted into the pCAL-c expression vector the cloned ORF will be in-frame with the CBP fusion tag. Because the three prime downstream primer did not contain a stop codon, a CBP fusion tag could be cloned in-frame with the Edg-1 ORF. Other cloning steps were performed essentially as described before. The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding a rat Edg-1-CBP fusion protein operably linked to a T7 promoter and lac repressor binding sites, is designated “prEDG-1-CBP” herein.[1094]
Example 4Cloning of a His-Tagged Rat Edg-1 into pCAL-c Expression Vector
• The rEdg-1 protein was manipulated to generate a fusion protein having a 6×His tag at its carboxyl terminus. A “6×His tag” or “His tag” is an amino acid sequence consisting of six contiguous histidine residues that can be used as an epitope for the binding of anti-6×His antibodies, or as ligand for binding nickel atoms. The His-tagged rEdg-1 fusion protein is used to detect rEdg-1 protein expression in the minicell expression system environment.[1095]
• The rEdg-1-6×His construct was cloned using the strategy described above for the construction of the rEdg-1-pCAL-c expression construct (prEDG-1), with the upstream primer having the sequence of SEQ ID NO:3, but with the exception that the three prime downstream primer (SEQ ID NO:34) was designed to contain six histidine codons followed by a stop codon. The 18 base pair 6×His tag was incorporated into the carboxyl terminus of the Edg-1 protein as expressed from the pCAL-c vector. Subsequent cloning procedures (PCR, restriction digest, gel purification, ligation, transformation, etc.) were performed as described previously for the Edg-1-pCAL-c construct (prEDG-1). The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding a carboxy-terminal His-tagged rat Edg-1-CBP fusion protein operably linked to a T7 promoter and lac repressor binding sites, is designated “prEDG-1-6×His” herein.[1096]
Example 5Amplification and Cloning of Rat Edg-3 Sequences
• The Edg-3 full length coding sequence was amplified via PCR from rat skeletal muscle mRNA using primers (SEQ ID NOS:35 and 36) designed from the known mouse sequence (Genbank accession NM[1097]_—010101). The mRNA used as a template for the amplification reaction was isolated using the RNeasy Miniprep Kit (Qiagen). Both the rtPCR and PCR amplification steps were carried out in a single reaction using the One Step RT-PCR Kit (Qiagen). The rEdg-3 PCR products were visualized with UV after electrophoresis in 1% TAE agarose gels and ethidium bromide staining.
• The predicted size of the amplified PCR products is 1145 base pairs. An appropriately-sized DNA band was isolated from the TAE gel and purified using the Geneclean Kit (BIO101). The purified band was ligated to the pCR3.1 vector using the TA-cloning kit (Invitrogen). Other cloning steps were carried out as described previously for the cloning of the rEdg-1-pCAL-c construct (prEDG-1)with the exception that the samples were screened using the EcoRI restriction enzyme. The expected sizes of the digested bands were 1145 base pairs and 5060 base pairs. Positive clones were analyzed by automated sequencing. The nucleotide sequences were analyzed using BLAST searches from the NCBI web site (www.ncbi.nlm.nih.gov/). The predicted full length rat Edg-3 amino acid sequence was assembled from the nucleotide sequencing data using in silico translation. The pCR3.1 vector comprising the rat Edg-3 ORF is designated “pCR-rEDG-3” herein.[1098]
Example 6Cloning of Rat Edg-3 Coding Sequences into the pCAL-c Expression Vector
• In order to express it in the minicell expression system, the rat Edg-3 ORF was cloned into the pCAL-c expression vector. The cloning strategy used was as described above for the cloning of the rat Edg-1 gene into the pCAL-c vector with the following exceptions. The primers used for PCR amplification were designed from the rat Edg-3 sequence and contained sites for the restriction enzymes NheI and KpnI (GGTACC). The NheI site was added to the five prime upstream primer (SEQ ID NO:37) and the KpnI site was added to the three prime downstream primer; SEQ ID NO:38). The NheI and KpnI restriction enzymes were used for the digestion reaction. The reaction mixture for the digestion step consisted of 1 μg of DNA, 1×restriction buffer (provided with the enzyme), and 1 μL of each enzyme. Plasmid preparations were screened by digestion with NheI and KpnI. The digested plasmid DNA was electrophosesed on a TAE agarose gel and visualized by UV after staining with ethidium bromide. The resultant band sizes were predicted to be 1145 base pairs and 5782 base pairs. The positive plasmid clones were analyzed with automated sequencing. The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding a rat Edg-3 protein operably linked to a T7 promoter and lac repressor binding sites, is designated “pEDG-3” herein.[1099]
Example 7Cloning of a His-Tagged Rat Edg-3 into the pCAL-c Expression Vector
• In order to detect expression of the rat Edg-3 protein in the minicell expression system, the rat Edg-3 coding sequence was manipulated so as to contain a 6×His tag at the carboxyl terminus of the protein. The cloning strategy used to create this construct was essentially the same as described above for the rEdg-3-pCAL-c (prEDG-3) construct cloning, with the upstream primer having the sequence of SEQ ID NO:37, with the exception that the three-prime downstream primer (SEQ ID NO:18) was designed to contain a 6×His coding sequence followed by a stop codon, which allowed for the incorporation of the 6×His amino acid sequence onto the carboxyl terminus of the Edg-3 receptor protein. Other cloning and screening steps were performed as described above. The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding a carboxy-terminal His-tagged rat Edg-3 fusion protein operably linked to a T7 promoter and lac repressor binding sites, is designated “prEDG-3-6×His” herein.[1100]
Example 8GFP Cloning into pCAL-c Expression Construct
• Cloning of GFP-encoding nucleotide sequences into the pCAL-c vector was performed in order to produce an expression construct having a reporter gene that can be used to detect protein expression (GFP, green flourescent protein). The cloning strategy used was essentially the same as the cloning strategy described above with the following exceptions. The template used for PCR amplification was the peGFP plasmid “construct” (GFP construct sold by Clontech). The primers used for amplification were designed from the GFP coding sequence and contained sites for the restriction enzymes NcoI and BamHI. The NcoI site was added to the five prime upstream primer (SEQ ID NO:40) and the BamHI site was added to the three prime downstream primer; see SEQ ID NO:41) The NcoI and BamHI restriction enzymes were used for the digestion reaction. The reaction mixture for the digestion step consisted of 1 μg of DNA, 1×restriction buffer (provided with the enzyme), and 1 μL of each enzyme. The screening of the plasmid preparations was carried out using NcoI and BamHI. Digested plasmid preparations were electrophoresed and visualized on TAE agarose gels with UV after staining with ethidium bromide. Restriction products having the predicted sizes of 797 and 5782 base pairs were seen. Positive plasmid clones were sequenced using an automated sequencer. The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding a rEdg-3-GFP fusion protein operably linked to a T7 promoter and lac repressor binding sites, is designated “prEDG-3-GFP” herein.[1101]
Example 9Design Construction of Control Expression Elements
• Control expression elements used to detect and quantify expression of proteins in minicells were preposed. These controls direct the expression of detectable proteins. An expression element used as positive control is pPTC12, which is supplied with the pCAL-c expression vector from Stratagene. This construct contains an ORF encoding a fusion protein comprising beta-galactosidase linked to CBP. Induction of expression of pTC12 should result in the production of a protein of about 120 kD, and this protein is detected via its enzymatic activity or by using antibodies directed to epitopes on the beta-galactosidase or CBP polypeptide.[1102]
• A GFP fusion construct was created and used as a positive control for the CBP detection kit. This construct was a positive control for induction of protein expression in the minicell expression system. The cloning strategy used to create the construct was essentially the same as that used for the cloning of the GFP into the pCAL-c expression vector, with the exception that the three prime downstream primer did not contain a stop codon; this allowed for the in frame incorporation of the CBP fusion tag to the GFP protein. The upstream primer had the sequence of SEQ ID NO:42, and the downstream primer had the sequence SEQ ID NO:43. The nucleotide sequence of the expression element was confirmed using an automated sequencer. The resulting plasmid, a pCAL-c derivative that comprises an ORF encoding GFP operably linked to a T7 promoter and lac repressor binding sites, is designated “pGFP-CBP” herein.[1103]
Example 10Introduction of pCAL-c Expression Constructs into the MC-T7Escherichia coliStrain
• The MC-T7[1104]E. colistrain was made competent using the CaCl₂technique. In brief, cells were grown in 40 mL LB medium to an OD₆₀₀of 0.6 to 0.8, and then centrifuged at 8000 rpm (7,700 g) for 5 min at 4° C. The pellet was resuspended in 20 mL of cold CaCl₂and left on ice for five minutes. The cells were then centrifuged at 8000 rpm (7,700 g) for 5 min at 4° C. The cell pellet was resuspended in 1 mL of cold CaCl₂and incubated on ice for 30 min. Following thisincubation 1 mL of 25% glycerol was added to the cells and they were distributed and frozen in 200 μL aliquots. Liquid nitrogen was used to freeze the cells. These cells subsequently then used for the transformation of expression constructs.
Example 11Preparation of Minicells
• To some degree, the preparation of minicells varied according to the type of expression approach that is used. In general, there are two such approaches, although it should be noted from the outset that these approaches are neither limiting nor mutually exclusive. One approach is designed to isolate minicells that already contain an expressed therapeutic protein or nucleic acid. Another approach is designed to isolate minicells that will express the protein or nucleic acid in the minicell following isolation.[1105]
• [1106]E. coliare inoculated into bacterial growth media (e.g., Luria broth) and grown overnight. After this, the overall protocol varies with regards to methods of induction of expression. The minicell producing cultures used to express protein post isolation are diluted and grown to the desired OD₆₀₀or OD450, typically in the log growth phase of bacterial cultures. The cultures are then induced with IPTG and then isolated. The IPTG concentration and exposure depended on which construct was being used, but was usually about 500 μM final for a short time, typically about 4 hours. This treatment results in the production of the T7 polymerase, which is under control of the LacUVR5 promoter, which is repressed by the LacI repressor protein. IPTG relieves the LacI repression and thus induces expression from the LacUVR5 promoter which controls expression of the T7 polymerase from the chromosome. This promoter is “leaky” that is, there is always a basal level of T7 polymerase which can be selected for or against so that the induction before isolation is not required. (This induction step is not required if a non-T7 expression system is used, as the reason for this step is to express the T7 RNA polymerase in the minicell-producing cells so that the polymerase and molecules segregate with the minicell.)
• The[1107]E. colicultures that produce minicells containing a therapeutic protein or nucleic acid have different induction protocols. The overnight cultures are diluted as described above; however, in the case of proteins that are not toxic to the parent cells, this time the media used for dilution already contains IPTG. The cultures are then grown to mid-log growth and minicells are isolated. These cultures produce the therapeutic protein or nucleic acid as they grow, and the minicells derived therefrom contain the therapeutic protein or nucleic acid.
• Altenatively or additionally, IPTG is added and expression is induced after the isolation of minicells. In the case of non-toxic proteins or nucleic acids that are expressed from expression elements in minicells, this treatment enhances production of the eposimally encoded gene product. In the case of toxic gene products induction post-isolation is preferred.[1108]
Example 12Minicell Isolation
• Minicells were isolated from the minicell producing MC-T7 strain of[1109]E. coliusing centrifugation techniques. The protocol that was used is essentially that of Jannatipour et al. (Translocation of Vibrio Harveyi N,N′-Diacetylchitobiase to the Outer Membrane ofEscherichia Coli,J. Bacteriol. 169: 3785-3791, 1987) and Matsumura et al. (Synthesis of Mot and Che Products ofEscherichia coliProgrammed by Hybrid ColE1 Plasmids in Minicells, J. Bacteriol. 132:996-1002, 1977).
• In brief, MC-T7 cells were grown overnight at 37° C. in 2 to 3 mL of LB media containing ampicillin (50 μg/mL), streptomycin (50 μg/mL), and tetracycline (50 μg/mL) (ampicillin was used only when growing MC-T7 cells containing a pCAL-c expression construct). The cells were diluted 1:100 in a total volume of 100 to 200 mL LB media with antibiotics, and grown at 37° C. until they reached an OD[1110]₆₀₀of 0.4 to 0.6, which is roughly beginning of the log growth phase for the MC-T7E. coli.During this incubation the remainder of the overnight culture was screened for the presence of the correct expression construct using the techniques described above. When the cultures reached the appropriate OD₆₀₀they were transferred to 250 mL GS3 centrifuge bottles and centrifuged (Beckman centrifuge) at 4500 rpm (3,500 g) for 5 min. At this point the supernatant contains mostly minicells, although a few relatively small whole cells may be present.
• The supernatant was transferred to a clean 250 mL GS3 centrifuge bottle and centrifuged at 8000 rpm (11,300 g) for 10 min. The pellet was resuspended in 2 mL of 1×BSG (10×BSG: 85 g NaCl, 3 g KH[1111]₂PO₄, 6 g Na₂HPO₄, and 1 g gelatin in 1 L ddH₂O) and layered onto a 32 mL 5 to 20% continuous sucrose gradient. The sucrose gradient was made with sucrose dissolved in 1×BSG.
• The sucrose gradient was then loaded in a Beckman SW24 rotor and centrifuged in a Beckman Ultracentrifuge at 4500 rpm (9,000 g) for 14 min. Following ultracentrifugation a single diffuse band of minicells was present. The top two thirds of this band was aspirated using a 10 mL pipette and transferred to a 30 mL Qakridge tube containing 10 mL of 1×BSG. The sample was then centrifuged at 13,000 rpm (20,400 g) for 8 min. Following centrifugation, the pellet was resuspended in 2[1112]mL 1×BSG, and the resuspended cells were loaded onto another 5 to 20% sucrose gradient. This sucrose gradient was centrifuged and the minicells were collected as described above. The sucrose gradient procedure was repeated a total of three times.
• Following the final sucrose gradient step the entire minicell band was collected from the sucrose gradient and added to a 30 mL Oakridge tube that contained 10 mL of MMM buffer (200[1113]mL 1×M9 salts, 2 mL 20% glucose, and 2.4 mL DIFCO Methionine Assay Medium). This minicell solution was centrifuged at 13,000 rpm (20,400 g) for 8 min. The pellet was resuspended in 1 mL of MMM Buffer.
• The concentration of minicells was determined using a spectrophotometer. The OD[1114]₄₅₀was obtained by reading a sample of minicells that was diluted 1:100.
Example 13Other Methods to Prepare and Isolate Minicalls
• By way of non-limiting example, induction of[1115]E. coliparental cells to form minicells may occur by overexpression of theE. coliftsZ gene. To accomplish this both plasmid-based and chromosomal overexpression constructs were created that place the ftsZ gene under the control of various regulatory elements (Table 6).

  TABLE 6
  REGULATORY CONSTRUCTS CONTROLLING
  FTSZ EXPRESSION.

  	Regulatory region	inducer	[inducer]	SEQ ID NO.:
  	Para::ftsZ	Arabinose	10mM	1, 3
  	Prha::ftsZ	Rhamnose		1 mM	2, 4
  	Ptac::ftsZ	IPTG	30 μM	5, Garrido et al.a

• Oligonucleotide Names and PCR Reactions Use the Following Format:[1116]
• “gene-1” is N-terminal, 100% homology oligo for chromosomal or cDNA amplification[1117]
• “gene-2” is C-terminal, 100% homology oligo for chromosomal or cDNA amplification[1118]
• “gene-1-RE site” is same sequence as gene-1 with additional residues for remainder of sequence, RE sites, and/or chimeric fusions.[1119]
• “gene-2-RE site” is same sequence as gene-1 with additional residues for remainder of sequence, RE sites, and/or chimeric fusions.[1120]
• Use “gene-1, 2” combo for chromosomal/cDNA amplification and “gene-1 RE site, gene-2-RE site” to amplify the mature sequence from the “gene-1, 2” gel-purified product.[1121]

  TABLE 7
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 6 CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence
  44	FtsZ-1	CCAATGGAACTTACCAATGACGCGG
  45	FtsZ-2	GCTTGCTTACGCAGGAATGCTGGG
  46	FtsZ-1-PstI	CGCGGCTGCAGATGTTTGAACCAATGGAACTTACCAATGACGCGG
  47	FtsZ-2-XbaI	GCGCCTCTAGATTATTAATCAGCTTGCTTACGCAGGAATGCTGGG

• Table 7 oligonucleotide sequences are for use in cloning ftsZ into SEQ ID NO.:1 and 2 (insertions of ftsZ behind the arabinose promotor (SEQ ID NO.: 1) and the rhamnose promotor (SEQ ID NO.: 2).[1122]

  TABLE 8
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR FTSZ CHROMOSOMAL
  DUPLICATION CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  48	Kan-1	GCTAGACTGGGCGGTTTTATGGACAGCAAGC
  49	Kan-2	GCGTTAATAATTCAGAAGAACTCGTCAAGAAGGCG
  50	Kan-1-X-frt	GCGCCTACTGACGTAGTTCGACCGTCGGACTAGCGAAGT
  		TCCTATACTTTCTAGAGAATAGGAACTTCGCTAGACTGG
  		GCGGTTTTATGGACAGCAAGC
  51	Kan-2-intD-frt	CAAGATGCTTTGCCTTTGTCTGAGTTGATACTGGCTTTGG
  		GAAGTTCCTATTCTCTAGAAAGTATAGGAACTTCGCGTT
  		AATAATTCAGAAGAACTCGTCAAGAAGGCG
  52	AraC-1	CGTTACCAATTATGACAACTTGACGG
  53	RhaR-1	TTAATCTTTCTGCGAATTGAGATGACGCC
  54	LacIq-1	GTGAGTCGATATTGTCTTTGTTGACCAG
  55	Ara-1-intD	GCCTGCATTGCGGCGCTTCAGTCTCCGCTGCATACTGTCC
  		CGTTACCAATTATGACAACTTGACGG
  56	RhaR-1-intD	GCCTGCATTGCGGCGCTTCAGTCTCCGCTGCATACTGTCCTTAATCTTTCTGCGAATTGAGATGACGCC
  57	LacIq-1-intD	GCCTGCATTGCGGCGCTTCAGTCTCCGCTGCATACTGTCC
  		TTAATAAAGTGAGTCGATATTGTCTTTGTTGACCAG
  58	FtsZ-1-X	GCCTGCATTGCGGCGCTTCAGTCTCCGCTGCATACTGTCCCGTTACCAATTATGACAACTTGACGG

• In like fashion, the ftsZ gene was amplified from SEQ ID NO.: 1, 2 and Ptac::ftsZ (Garrido, T. et al. 1993. Transcription of ftsZ oscillates during the cell cycle of[1123]Escherichia coli.EMBO J. 12:3957-3965) plasmid and chromosomal constructs, respectively using the following oligonucleotides:
• For amplification of araC through ftsZ of SEQ ID NO.: 1 use oligonucleotides:[1124]
• AraC-1[1125]
• FtsZ-2[1126]
• For amplification of rhaR through ftsZ of SEQ ID NO.: 2 use oligonucleotides:[1127]
• RhaR-1[1128]
• FtsZ-2[1129]
• For amplification of lacI[1130]^qthrough ftsZ of Ptac::ftsZ (Garrido, T., et al.) use oligonucleotides:
• lacI[1131]^q-1
• ftsZ-2[1132]
• The above amplified DNA regions were gel-purified and used as template for the second round of PCR using oligonucleotides containing homology with the[1133]E. colichromosomal gene intD and on the other end with random sequence termed “X”. Oligonucleotides used in this round of PCR are shown below:
• For amplification of araC through ftsZ from SEQ ID NO.: 1 to contain homology to intD and the random X use oligonucleotides:[1134]
• AraC-1-intD[1135]
• FtsZ-1-X[1136]
• For amplification of rhaR through ftsZ from SEQ ID NO.: 2 to contain homology to intD and the random X use oligonucleotides:[1137]
• RhaR-1-intD[1138]
• FtsZ-1-X[1139]
• For amplification of laclq through ftsZ from Ptac::ftsZ to contain homology to intD and the random X use oligonucleotides:[1140]
• LacIq-1-intD[1141]
• FtsZ-1-X[1142]
• The PCR products from these PCR reactions are as shown below:[1143]
• intD−araC−Ara promotor−ftsZ−“X”[1144]
• intD−rhaRS−Rha promotor−ftsZ−“X”[1145]
• intD−lacI[1146]^q−Ptac promotor−ftsZ−“X”
• To amplify the mature complexes, the following regions were mixed and amplified with the coupled oligonucleotide sequence primers:[1147]
• SEQ ID NO.: 3 was Produced Using:[1148]

  
• SEQ ID NO.: 4 was Produced Using:[1149]

  
• SEQ ID NO.: 5 was Produced Using:[1150]

  
• These expression constructs may be expressed from the plasmid, placed in single copy, replacing the native ftsZ copy on the[1151]E. colichromosome (Garrido, T., et al. 1993. Transcription of ftsZ oscillates during the cell cycle ofEscherichia coli.EMBO J. 12:3957-3965), or in duplicate copy retaining the native ftsZ copy while inserting one of the expression constructs in Table 6 into the intD gene on the same chromosome. Chromosomal duplications were constructed using the RED recombinase system (Katsenko, K. A., and B. L. Wanner. One-Step Inactivation of Chromosomal Genes inEscherichia coliK-12 Using PCR Products. Proc. Natl. Acad. Sci. 97:6640-6645. 2000) and are shown in SEQ ID NO 3-5. The later constructs allow native replication during non-minicell producing conditions, thus avoiding selective pressure during strain construction and maintenance. Furthermore, these strains provide defined points of minicell induction that improve minicell purification while creating conditions that allow strain manipulation prior to, during, and following minicell production. By way of non-limiting example these manipulations may be protein production that the cytoplasmic redox state, modify plasmid copy number, and/or produce chaperone proteins.
• For minicell production, a minicell producing strain described in the previous section is grown overnight in Luria broth (LB) supplemented with 0.1% dextrose, 100 μg/ml ampicillin, and when using the single-copy ftsZ construct, 15 μM IPTG. All incubations were performed at 37° C. For minicell induction only, overnight strains are subcultured 1/1000 into the same media. If minicell induction is to be coupled with co-expression of other proteins that are controlled by a catabolite repression-sensitive regulator, dextrose was excluded. Minicell induction is sensitive to aeration and mechanical forces. Therefore, flask size, media volume and shake speed is critical for optimal yields. Likewise, bioreactor conditions must be properly regulated to optimize these production conditions.[1152]
• In shake-flask cultures, strains are grown to early exponential (log) phase as monitored by optical density (OD) at 600 nm (OD[1153]₆₀₀0.05-0.20). (Bioreactor conditions may differ significantly depending on the application and yield desired). For minicell induction alone, early log phase cultures are induced with the appropriate inducer concentration shown in Table 6. For coupled co-expression, these cultures are induced as shown in Table 6 for the appropriate minicell regulator, while the coupled protein(s) is induced with the inducer appropriate for the regulator controlling the synthesis of that protein. Cultures are grown under the appropriate conditions and harvested during late log (OD₆₀₀0.8-1.2). Depending on the application, minicell induced cultures may be immediately chilled on ice prior to purification, or maintained at room temperature during the harvesting process.
• To separate minicells from viable, parental cells, cultures are subjected to differential centrifugation (Voros, J., and R. N. Goodman. 1965. Filamentous forms of[1154]Erwinia amylovora.Phytopathol. 55:876-879). Briefly, cultures are centrifuged at 4,500 rpm in a GSA rotor for 5 min. Supernatants are removed to a fresh bottle and centrifuged at 8,000 rpm for an additional 10 min to pellet minicells. Pelleted minicells (containing contaminating parental cells) are resuspended in 2 ml LB, LBD (LB supplemented with 0.1% dextrose), Min (minimal M63 salt media) (Roozen, K. J., et al. 1971. Synthesis of ribonucleic acid and protein in plasmid-containing minicells ofEscherichia coliK-12. J. Bacteriol. 107:21-23), supplemented with 0.5% casamino acids) or MDT (minimal M63 salt media, supplemented with 0.5% casamino acids, 0.1% dextrose, and thiamine). Resuspended minicells are next separated using linear density gradients. By way of non-limiting example, these gradients may contain sucrose (Cohen A., et al. 1968. The properties of DNA transferred to minicells during conjugation. Cold Spring Harb. Symp. Quant. Biol. 33:635-641), ficol, or glycerol. For example, linear sucrose gradients range from 5-20% and are poured in LB, LBD, Minor MDT. Using a SW28 swinging bucket rotor, gradients are centrifuged at 4,500 rpm for 14 min. Banded minicells are removed, mixed with LB, LBD, Minor MDT, and using a JA-20 rotor are centrifuged at 13,000 rpm for 12 min. Following centrifugation, pellets are resuspended in 2 ml LB, LBD, Minor MDT and subjected to a second density gradient. Following the second density separation, banded minicells are removed from the gradient, pelleted as described, and resuspended in LB, LBD, Minor MDT for use and/or storage.
• Purified minicells are quantitated using an OD[1155]₆₀₀measurement as compared to a standard curve incorporating LPS quantity, minicell size, and minicell volume. Quantitated minicells mixtures are analyzed for contaminating, viable parental cells by plating on the appropriate growth media (Table 9).

  TABLE 9
  MINICELL PURIFICATION AND PARENTAL
  CELL QUANTITATION

  		Total		Fold-
  Purification	Total cells	parental cells	MC/PC ratio	purification
  Before	4.76 × 1011	3.14 × 1011	0.25/1	—
  After	1.49 × 1011	6.01 × 104	2.48 × 106/1	5.23 × 106

Example 14Protoplast Formation
• In order to allow a membrane receptor to be presented to the outside environment (displayed), minicells are made into protoplasts. In order to make the integral membrane protein receptors in the inner membrane more accessible for ligand binding, the outer membrane and cell wall were removed. The removal of the outer membrane and cell wall from[1156]E. coliwhole cells and minicells to produce protoplasts was performed essentially according to previously described protocols with a few modifications (Birdsell et al., Production and Ultrastructure of Lysozyme and Ethylenediaminetetraacetate-Lysozyme Spheroplasts ofEscherichia coli,J. Bacteriol. 93:427-437, 1967; Weiss et al., Protoplast Formation inEscherichia Coli,J. Bacteriol. 128:668-670, 1976. Both minicells and whole cells were processed the same way.
• In brief, the cells were grown to mid-log phase and pelleted at room temperature (minicells were isolated from cultures in mid-log phase). The pellet was washed twice with 10 mM Tris. Following the second wash protoplast production may be performed using two approaches. In the first approach, following the second wash, the cells were resuspended in 100 mM Tris (pH 8.0) that contained 6-20% sucrose and put in a 37° C. waterbath (the Tris/sucrose buffer was pre-warmed to 37° C.). The volume used to resuspend the cells was determined by the following equation: (volume of cells×OD[1157]₄₅₀)/10=resuspension volume. After a 1 minute incubation, 2 mg/mL lysozyme was added to a final concentration of 5-100 μg/mL. The samples were then incubated for 12 minutes at 37° C. while being gently mixed. Next, 100 mM EDTA (pH 7) was slowly added over a period of 2.5 minutes (amount of EDTA added=1/00-1/10 volume of cells) followed by a 10 min incubation at 37° C. The protoplasts are also diluted from 20% sucrose down to either 10% or 5% sucrose, which facilitates the complete removal of the outer membrane and cell wall. The protoplasts thus generated were separated from the outer membrane and cell wall using a sucrose step gradient. A sucrose step gradient does not have a gradual increase in sucrose percentage; rather, it goes directly from one percent to the other. For example, protoplasts generated from whole cells are loaded on a step gradient that is made from 5% and 15% sucrose. The protoplasts spin through the 15% sucrose but the debris generated when making the protoplasts does not spin through the 15% sucrose. The protoplasts are thus separated from the debris. The second method to prepare protoplasts, following the second wash, 1×10⁹cells were resuspended with 50 mM Tris, pH 8.0 containing 0.5-50 mM EDTA and 6-20% sucrose. This mixture was incubated at 37° C. for 10 min. Following incubation, the mixture was centrifuged at 13,200 RPM in a microcentrifuge for 2 min. After centrifugation, the pellet was resuspened in 50 mM Tris, pH 8.0 containing 5-100 μg/ml lysozyme and 6-20% sucrose. This-mixture was incubated at 37° C. for 10 min. Following incubation, the mixture was centrifuged at 13,200 RPM in a microcentrifuge for 2 min, resuspended in 50 mM Tris pH 8.0 containing 6-20% sucrose for use.
• An alternative method to remove contaminating LPS is to use affinity absorption with an anti-LPS antibody (Cortex). To accomplish this, the anti-LPS antibody was coated on either an activated agarose or sepharose matrix (Sigma) or epoxy-coated magnetic M-450 beads (Dynal). The spheroplast/protoplast mixture was subjected to the antibody coated matrix either in batch or using column chromatographic techniques to remove contaminating LPS. Following exposure, the unbound fraction(s) was collected and re-exposed to fresh matrix. To monitor the efficiency of the protoplasting reaction and LPS removal, three constructs were used (Table 10).[1158]

  TABLE 10
  PROTOPLAST MONITORING CONSTRUCTS

  	SEQ		SEQ	Inducible
  Construct	ID NO	Plasmid	ID NO	protein	Inducer
  PMPX-5	6	pMPX-32	7	ΔphoA	Rhamnose
  PMPX-5	6	pMPX-53	8	phoA	Rhamnose
  PMPX-5	6	pMPX-33	9	toxR-phoA	Rhamnose

• [1159]

  TABLE 11
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 10 CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  59	ΔphoA-1	GCCTGTTCTGGAAAACCGGGCTGCTCAGGG
  60	ΔphoA-2	GCGGCTTTCATGGTGTAGAAGAGATCGG
  61	ΔphoA-1-PstI	CCGCGCTGCAGATGCCTGTTCTGGAAAACCGGGCTGCTCAGGG
  62	ΔphoA-2-XbaI	GCGCCTCTAGATTTATTATTTCAGCCCCAGAGCGGCTTTCATG
  		GTGTAGAAGAGATCGG
  63	PhoA-1	GTCACGGCCGAGACTTATAGTCGC
  64	PhoA-2	GCGGCTTTCATGGTGTAGAAGAGATCGG
  65	PhoA-1-PstI	CCGCGCTGCAGATGTCACGGCCGAGACTTATAGTCGC
  66	PhoA-2-XbaI	GCGCCTCTAGATTATTATTTCAGCCCCAGAGCGGCTTTCATG
  		GTGTAGAAGAGATCGG
  67	T-phoA-1-PstI	CCGCGCTGCAGATGAACTTGGGGAATCGACTGTTTATTCTGA
  		TAGCGGTCTTACTTCCCCTCGCAGTATTACTGCTCATGCCTG
  		TTCTGGAAAACCGGGCTGCTCAGGG
  68	T-phoA-2-XbaI	GCGCCTCTAGATTATTATTTCAGCCCCAGAGCGGCTTTCATG
  		GTGTAGAAGAGATCGG

• Oligonucleotides SEQ ID NOS.:59, 60, 61 and 62 were used to amplify phoA lacking a leader sequence (ΔphoA) form the[1160]E. colichromosome. Once amplified, this region was inserted into SEQ ID NO.: 6 using PstI and XbaI to create SEQ ID NO.:7.
• Oligonucleotides SEQ ID NOS.:63, 64, 65 and 66 were used to amplify phoA containing a leader sequence (phoA) form the[1161]E. colichromosome. Once amplified, this region was inserted into SEQ ID NO.: 6 using PstI and XbaI to create SEQ ID NO.: 8.
• Oligonucleotides SEQ ID NOS.:59, 60, 67 and 68 were used to amplify phoA lacking a leader sequence (ΔphoA) form the[1162]E. colichromosome and form a translational fusion between the transmembrane domain of toxR fromVibrio cholerae.Once amplified, this region was inserted into SEQ ID NO.: 6 using PstI and XbaI to create SEQ ID NO.: 9.
• By co-expression of minicells and protein, minicells were prepared that contained cytoplasmic PhoA (pMPX-32 expresses phoA lacking a leader sequence [ΔphoA]), periplasmic PhoA (pMPX-53 expresses native phoA that exports to the periplasmic space), or inner membrane-bound PhoA (pMPX-33 expresses phoA lacking a leader sequence fused to the transmembrane domain (TMD) of the toxR gene product from[1163]Vibrio cholerae). Using these expressed proteins, the efficiency of minicell protoplasting was monitored (Table 12).

  TABLE 12
  EFFICIENCY OF MINICELL PROTOPLAST
  PREPARATION AND PURIFICATION

  Step	Locationa	ΔPhoA	PhoA	T-PhoA	LPS totalb

  Minicell	Pellet	100	100	100	100
  EDTA/lysozyme	Whole	100	100	100	100
  1st Anti-LPS	Pellet	80	0	80	30
  2nd Anti-LPS	Pellet	60	0	60	0

• The data suggests that periplasmic PhoA is lost during the preparation, while both cytoplasmic and membrane-bound PhoA are retained in a cellular body that lacks LPS. However, during this process ˜40% of the total minicell content is lost.[1164]
Example 15T7-Dependent Induction of Expression
• Expression from the pCAL-c expression vector is driven from a T7 bacteriophage promoter that is repressed by the LacI gene product. Transcription of the DNA into mRNA, and subsequent translation of mRNA into proteins, does not occur as long as the LacI repressor is bound to the T7 promoter. However, in the presence of IPTG, the LacI repressor does not bind the T7 promoter. Thus, induction of expression from pCAL-c sequences is dependent on the presence of IPTG. Slightly different protocols were used for the induction of Escherichia coli whole and for the induction of minicells. Slight differences are also present in the protocols for induction of minicells for 35S-methionine labeling of proteins in contrast to those for the induction of minicells for Western blot analysis. These induction protocols are described bellow.[1165]
• For expression in[1166]E. coliwhole cells, the cells were first grown overnight in 3 mL of LB and antibiotics. The cultures were screened for the presence of the desired expression element as previously described. Cultures containing the desired expression elements were diluted 1:100 and grown to an OD₆₀₀of between 0.4 to 0.6. The culture size varied depending on the intended use of the cells. IPTG was then added to a final concentration of 200 μg/mL, and the cells were shaken at 30° C. for 4 hours. Following the induction, cells were harvested for analysis.
• The induction of minicells was carried out as follows. The minicells were diluted in MMM buffer to 1 mL total volume according to the concentration obtained from the isolation procedure (OD[1167]₄₅₀of about 0.5). The cells were then treated with 50 μg/mL of cycloserine for 30 minutes at 37° C. to stop whole cell growth. Following the cycloserine treatment the cells were provided with an amino acid, methionine, which the MMM buffer does not contain. For³⁵S-labeled protein induction³⁵S-methionine was added to the minicell sample whereas, for unlabeled protein induction unlabeled methionine was added. Fifteen (15) μCi of³⁵S-methionine (Amersham Pharmacia Biotech, Piscataway, N.J.) was added to the samples for radiolabeling and 5 μmol of methionine was added to the non-labeled minicell samples. Two hundred (200) μg/mL IPTG was also added to the minicell samples, which were then shaken at 30° C. for about 4 hours. Following induction, the minicells were harvested for further preparation or analysis.
Example 16Western Blot Ananlysis
• The CBP detection kit was purchased from Stratagene. SDS running buffer, 10% Tris-HCl ready gels, Kaleidoscope Pre-stained Standards, and Laemmli Sample Buffer were purchased from BIO RAD (Hercules, Calif.). GFP (FL) HRP antibodies were purchased from Santa Cruz Biotechnology (Santa Cruz, Calif.). Edg-3CT antibody an antibody directed to the carboxy terminus of was purchased from Exalpha Biologicals (Boston, Mass.). Anti-6×His antibody, positrope, and the WesternBreeze Kit were purchased from Invitrogen (Carlsbad, Calif.). Protocols were carried out essentially according to the manufacturer's instructions unless otherwise indicated.[1168]
• Three different Western blot protocols were used to detect protein expression in both a minicell expression system and in a whole cell expression system. For both systems, the SDS-PAGE gel and the transfer protocols were essentially as follows. The samples were denatured by diluting the samples 1:1 in Laemmli buffer (BIORAD) and then sonicated for 10 min. The denatured samples were loaded onto a 10% Tris-Glycine gel (BIORAD) and electrophoresed at 130 V for about 1.5 hours in 1×SDS running buffer (BIORAD). The electrophoresed proteins were electrotransferred to nitrocellulose membranes at 0.5 Amps for 1.5 hours in Transfer Buffer (5.8 g Tris, 2.9 g glycine, 200 mL methanol, and 3.7 mL of 10% SDS). The nitrocellulose membranes comprising the transferred proteins were used for Western bloting.[1169]
• GFP Western blots were carried out as follows. The nitrocellulose membrane was blocked for 2 hours with 5% milk in PBST (PBS buffer with 0.05% Tween). Following the blocking step the nitrocellulose membrane was washed twice with PBST. For the detection of GFP protein, an anti-GFP-HRP conjugated antibody (Santa Cruz Biotechnology) was used at a dilution of 1:3000 in PBST (HRP, horse radish peroxidase). The nitrocellulose membrane was incubated in the anti-GFP-HRP antibody solution for one hour and then washed twice with PBST. GFP proteins on the nitrocellulose membrane were detected and visualized using the ECL system (Amersham).[1170]
• The His-tagged Edg-1 and Edg-3 proteins were detected using a mouse anti-6×His antibody from Invitrogen and the WesternBreeze chemoluminecent Kit (Invitrogen). The antibody was diluted 1:4000 in buffers provided by the WesternBreeze Kit. The WesternBreeze immunoblot was carried out essentially according to the manufacturer's protocol. The Edg-1-CBP and GFP-CBP fusion proteins were detected using the CBP detection Kit (Stratagene). All antibodies and substrates were provided in the Kit. FIG. 3 is a photo of the Western hybridization results showing the presence of Edg-1-6×His and Edg-3-6×His in minicells and parent cells.[1171]
Example 17Methods to Induce Expression
• Expression in minicells may proceed following purification of minicells and/or minicell protoplasts from parental cells and LPS constituents, repectively. However, for some applications it is suitable to co-express proteins of interest with minicell induction. For these approaches, one may use the protocol described in EXAMPLE 13 for expression of the phoA constructs. By way of non-limiting example, either of these approaches may be accomplished using one or more of the following expression constructs (Table 13).[1172]

  TABLE 13
  EXPRESSION CONSTRUCTS

  				SEQ ID
  Plasmid	Regulatory element(s)	inducer	Plasmid	NO.:

  pMPX-5	rhaRS	Rhamnose	pUC-18	6
  pMPX-7	uidR	β-glucuronate	pUC-18	10
  pMPX-8	melR	Melibiose	pUC-18	11
  pMPX-18	araC	Arabinose	pUC-18	12
  pMPX-6	araC	Arabinose	pUC-18	13

• [1173]

  TABLE 14
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 13 CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  69	Rha-1	GCGAATTGAGATGAGGCCACTGGC
  70	Rha-2	CCTGCTGAATTTCATTAACGACCAG
  71	Rha-1-HindIII	CGGCGAAGCTTAATTAATCTTTCTGCGAATTGAGATGACGCCACTGGC
  72	Rha-2-PstI	CGCCGTAATCGCCGCTGCAGAATGTGATCCTGCTGAATTTC
  		ATTAACGACCAG
  73	Uid-1	CGCAGCGCTGTTCCTTTTGCTCG
  74	Uid-2	CCTCATTAAGATAATAATACTGG
  75	Uid-1-HindIII	GCCGCAAGCTTCGCAGCGCTGTTCCTTTGCTCG
  76	Uid-2-PstI	CCAATGCATTGGTTCTGCAGGACTCCTCATTAAGATAATAATACTGG
  77	Mel-1	CGTCTTTAGCCGGGAAACG
  78	Mel-2	GCAGATCTCCTGGCTTGC
  79	Mel-1-HindIII	GCCGCAAGCTTCGTCTTTAGCCGGGAAACG
  80	Mel-2-SalI	CGGTCGACGCAGATCTCCTGGCTTGC
  81	Ara-1	CAAGCCGTCAATTGTCTGATTCG
  82	Ara-2	GGTGAATTCCTCCTGCTAGCCC
  83	Ara-1-HindIII	GCGCCAAGCTTCAAGCCGTCAATTGTCTGATTCG
  84	Ara-2-PstI	CTGCAGGGTGAATTCCTCCTGCTAGCCC
  85	Ara-1-XhoI	GCTTAACTCGAGCTTAATAACAAGCCGTCAATTGTCTGATTC
  86	Ara-2-SstI	GCTTAACCGCGGGCCAAGCTTGCATGCCTGCTCC

• Oligonucleotides SEQ ID NOS.:69, 70, 71 and 72 were used to amplify the rhaRS genes and their divergent control region from the[1174]E. colichromosome. Once amplified, this region was inserted into pUC18 using HindIII and PstI to create SEQ ID NO.: 6.
• Oligonucleotides SEQ ID NOS.:73, 74, 75 and 76 were used to amplify the uidR control region, the uidR gene and the control region for expression from the[1175]E. colichromosome. Once amplified, this region was inserted into pUC18 using HindIII and PstI to create SEQ ID NO.: 10.
• Oligonucleotides SEQ ID NOS.:77, 78, 79 and 80 were used to amplify the melR gene and its divergent control region from the[1176]E. colichromosome. Once amplified, this region was inserted into pUC18 using HindIII and SalI to create SEQ ID NO.: 11.
• Oligonucleotides SEQ ID NOS.:81, 82, 83 and 84 were used to amplify the araC gene and its divergent control region from the[1177]E. colichromosome. Once amplified, this region was inserted into pUC18 using HindIII and PstI to create SEQ ID NO.: 12.
• Oligonucleotides SEQ ID NOS.:81, 82, 85 and 86 were used to amplify the araC gene and its divergent control region was PCR amplified from pBAD-24. Once amplified, this region was inserted into pEGFP (Clontech) using XhoI and SstI to create SEQ ID NO.: 13.[1178]
• Except of pMPX-6, these expression constructs contain the same multiple cloning site. Therefore, any protein of interested may be inserted in each modular expression construct for simple expression screening and optimization.[1179]
• By way of non-limiting example, other proteins that may be expressed are listed in Table 15.[1180]

  TABLE 15
  OTHER EXPRESSED PROTEINS

  				SEQ ID
  Protein	Origin	Construct	Purpose	NO.:

  Edg3	Rat	native	GPCR	14
  β2AR	Human	native	GPCR	15
  TNFR-1a	Human	residues	Receptor	18
  (human)		29-455
  TNFR-1b	Human	residues	Receptor	17
  (human)		41-455
  TNF	Human	native	Gene transfer	19
  (human)
  T-EGF	Human	chimera	Gene transfer	20
  T-Invasin	Y.	chimera	Gene transfer	21
  	pseudotuberculosis

• [1181]

  TABLE 16
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 15

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  87	Edg-1	GGCAACCACGCACGCGCAGGGCCACC
  88	Edg-2	CAATGGTGATGGTGATGATGACCGG
  89	Edg-1-SalI	CGCGGTCGACATGGCAACCACGCACGCGCAGGGCCACC
  90	Edg-2-KpnI	GCGCCGGTACCTTATCAATGGTGATGGTGATGATGACCGG
  91	β2AR-1	GGGGCAACCCGGGAACGGCAGCGCC
  92	β2AR-2	GCAGTGAGTCATTTGTACTACAATTCCTCC
  93	β2AR-1-SalI	CGCGGTCGACATGGGGCAACCCGGGAACGGCAGCGCC
  94	β2AR-2-BamHI	GCGCCGGATCCTTATTATAGCAGTGAGTCATTTGTACTAC
  		AATTCCTCC
  95	TNFR(29)-1	GGACTGGTCCCTCACCTAGGGGACAGGG
  96	TNFR(29)-2	CTGAGAAGAGTGGGCGCGGGCGGGAGG
  97	TNFR(29)-1-SalI	CGCGGGTCGACATGGGACTGGTCCCTCACCTAGGGGACAGGG
  98	TNFR(29)-2-KpnI	GCGCCGGTACCTTATTACTGAGAAGACTGGGCGCGGGCGGGAGG
  99	TNFR(41)-1	GATAGTGTGTGTCCCC
  100	TNFR(41)-2	CTGAGAAGACTGGGCGC
  101	TNFR(41)-1-NcoI	GGGAGACCATGGATAGTGTGTGTCCCC
  102	TNFR(41)-2-XbaI	GCCTCATCTAGATTACTGAGAAGACTGGGCGC
  103	TNF-1	GAGCACTGAAAGCATGATCCGGGACG
  104	TNF-2	CAGGGCAATGATCCCAAAGTAGACCTGC
  105	TNF-1-EcoRI	CCGCGGAATTCATGAGCACTGAAAGCATGATCCGGGACG
  106	TNF-2-HindIII	GGCGCAAGCTTATCACAGGGCAATGATCCCAAAGTAGACCTGC
  107	T-EGF-1	TCTGATAGCGGTCTTACTTCCCCTCGCAGTATTACTGCTC
  		AATAGTGACTCTGAATGTCCCCTGTCCCACGATGGGTACT
  		GCCTCCATGATGGTGTGTGCATGTATATTG
  108	T-EGF-2	AGGTCTCGGTACTGACATCGCTCCCCGATGTAGCCAACA
  		ACACAGTTGCATGCATACTTGTCCAATGCTTCAATATACA
  		TGCACACACCATCATGGAGGCA
  109	T-EGF-3	CCGCGGGTACCATGAACTTGGGGAATCGACTGTTTATTCT
  		GATAGCGGTCTTACTTCCCCTCG
  110	T-EGF-4	GCGCCAAGCTTATTAGCGCAGTTCCCACCACTTCAGGTCT
  		CGGTACTGACATCGCTCCCCG
  111	Inv-1	TCATTCACATTGAGCGTCACCG
  112	Inv-2	TTATATTGACAGCGCACAGAGCGG
  113	Inv-1-ToxR-EcoRI	GCAAGAATTCACCATGAACTTGGGGAATCGACTGTTTATT
  		CTGATAGCGGTCTTACTTCCCCTCGCAGTATTACTGCTCT
  		CATTCACATTGAGCGTCACCG
  114	Inv-2-PstI	CGCGGTTACGTAAGCAACTGCAGTTATATTGACAGCGCACAGAGCGG

• Oligonucleotides SEQ ID NOS.:87, 88, 89 and 90 were used to amplify rat Edg3 from rat cDNA. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using SalI and KpnI to create SEQ ID NO.:14.[1182]
• Oligonucleotides SEQ ID NOS.:91, 92, 93 and 94 were used to amplify human β2 adrenergic receptor (β2AR) from human heart cDNA. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using SalI and BamHI to create SEQ ID NO.:15.[1183]
• Oligonucleotides SEQ ID NOS.:95, 96, 97 and 98 were used to amplify human tumor necrosis factor receptor (TNFR residues 29-455) from human Jurkat CL71 cDNA. Once amplified, this region was inserted into SEQ ID NO.: 12 (pMPX-18) using SalI and KpnI to create SEQ ID NO.:18.[1184]
• Oligonucleotides SEQ ID NOS.:99, 100, 101 and 102 were used to amplify human tumor necrosis factor receptor (TNFR residues 41-455) from human Jurkat CL71 cDNA. Once amplified, the region was inserted into pBAD24 using NcoI and XbaI to create SEQ ID NO.:17.[1185]
• Oligonucleotides SEQ ID NOS.:103, 104, 105 and 106 were used to amplify human tumor necrosis factor (TNF) from human Jurkat CL71 cDNA. Once amplified, this region was inserted into SEQ ID NO.: 13 (pMPX-6) using EcoRI and HindIII to create SEQ ID NO.:19.[1186]

  TABLE 17
  PROGRAM TO ANNEAL GRADIENT PCR WITH
  PFX POLYMERASE

  	Step	Temp (° C.)	Time (min)
  	1	95	2.0
  	2	95	0.5
  	3	64	0.5
  	4	68	2.5
  	5	Goto 2, 2X
  	6	95	0.5
  	7	62	0.5
  	8	68	2.5
  	9	Goto 6, 4X
  	10	95	0.5
  	11	60	0.5
  	12	68	2.5
  	13	Goto 10, 6X
  	14	95	0.5
  	15	58	0.5
  	16	68	2.5
  	17	Goto 14, 24X
  	18	4	hold
  	19	end

• Oligonucleotides SEQ ID NOS.:107, 108, 109 and 110 were mixed and PCR amplified using anneal gradient PCR (Table 17) to form mature human epidermal growth factor (EGF) (residues 971-1023 translationally fused to the transmembrane domain of toxR from[1187]Vibrio cholerae.Once amplified this region was inserted into SEQ ID NO.: 13 (pMPX-6) using KpnI and HindIII to create SEQ ID NO.:20.
• Using PFX polymerase (Invitrogen) oligonucleotide SEQ ID NO.:111, 112, 113 and 114 were used to amplify invasin residues 490-986 (inv) from[1188]Yersinia pseudotuberculosischromosomal DNA and form a translational fusion between the transmembrane domain of toxR fromVibrio cholerae.Once amplified, this region was inserted into SEQ ID NO.:13 (pMPX-6) using EcoRI and PstI to create SEQ ID NO.:21.
• These proteins were proof-of-principle constructs used to evaluate the minicell platform. For purposes of this initial evaluation, all proteins except TNF, T-EGF and T-Invasin were cloned into pMPX-5, with these later proteins cloned into pMPX-6 for gene transfer experiments.[1189]
• Whether the approach for protein expression is co-expression with minicell induction or expression following minicell and/or protoplast isolation, the procedure to transform the expression constructs is the same. To accomplish this, protein constructs were initially cloned into[1190]E. coliMG1655 and then into the minicell producing strain of interest. Transformation events were selected prior to minicell induction. For co-induction of protein and minicells, see the protocol for phoA expression above. For post-minicell and/or protoplast purification induction experiments, following minicell purification and/or protoplast preparation and purification, these cellular bodies were induced for protein production in either LBD or MDT at a minicell or protoplast/volume ratio of 1×10⁹minicell or photoplasts/1 ml media. Media was supplemented with the appropriate inducer concentration (see Table 6). Protein induction is sensitive to a variety of factors including, but not limited to aeration and temperature, thus reaction volume to surface area ratio is important, as is the method of shaking and temperature of induction. Therefore, each protein must be treated as required to optimize expression. In addition to expression parameters, protoplasted minicells are sensitive to osmotic and mechanical forces. Therefore, protoplast protein induction reactions must also contain 10% sucrose with greater volume to surface area ratios than required for intact minicells to achieve similar aeration at lower revolutions.
• Using the T-PhoA as a non-limiting example, protein expression was performed during and following minicell isolation. To accomplish this task, t-phoA co-expressed with minicell induction was compared to t-phoA expressed after minicell isolation. In both cases, overnight minicell-producing parental strains containing pMPX-5::t-phoA were subcultured into LBD supplemented with the appropriate antibiotic. Cultures were grown to OD[1191]₆₀₀0.1 and induced for minicell production alone or for both minicell and protein production. Both cultures were harvested at OD₆₀₀1.0 and minicells produced were harvested as described above. Minicells to be induced for T-phoA production following purification were induced by introducing 1×10⁹purified minicells into a 15 ml culture tube containing 1 ml MDT with 1 mM L-rhamnose. Minicell protein induction was allowed to proceed for up to 14 hours and compared to protein production obtained using the co-expression approach. For each approach, minicells were fractionated and analyzed for membrane association, total protein, and membrane association-dependent enzymatic activity. These observations were compared to post-induction, pre-isolation parental cell/minicell (PC/MC) mixtures from the co-expressed reactions. The first observation was that co-expression of minicell and protein induction was superior to post-minicell purification induction (Table 18). However, although the kinetics are slower for the post-minicell purification induction protocol, the end result is equivalent.

  TABLE 18
  COMPARATIVE EXPRESSION: CO-EXPRESSION
  VERSUS POST MINICELL PURIFICATION INDUCTION

  Time of induction	Purified minicell inductiona	Co-expression inductiona

  1.0	8.0	—
  2.0	—	812.2
  4.0	70.0	—
  14.0	445.0	—

• Using the co-expression induction procedure, the amount of membrane-associated T-PhoA was measured and compared for both parental cells and minicells. Briefly, following co-expression induction of T-PhoA and minicells, minicells were purified and their membranes isolated. For membrane isolation, minicells containing expressed T-PhoA were subjected to three rounds of freeze-thaw lysis in the presence of 10 μg/ml lysozyme. Following freeze-thaw cycling, the reaction was subjected to sonication. Sonicated material was centrifuged at 6,000 rpm in a microcentrifuge for 5 min at room temperature. Supernatants were transferred to a fresh 1.5 ml Eppendorf tube and centrifuged at 70,000 rpm using a TLA-100 rotor. Following centrifugation, the pellet was resuspended in buffer and analyzed for total T-PhoA protein (Table 19) and T-PhoA enzyme activity (Table 20).[1192]

  TABLE 19
  MEMBRANE ASSOCIATED T-PHOA: PARENTAL
  CELLS VERSUS MINICELLS

  				Protein	T-PhoA	T-PhoA
  	Protein	T-PhoA	T-PhoA	membrane	membrane	% membrane
  Cell typea	totala	totalb	% total	associateda	associatedb	protein total

  Parental cells	107.5	5.3	4.9	10.7	3.1	29.0
  Minicells	4.6	0.8	17.5	1.0	0.5	50.0
  Minicells EQb	25.2	4.4	—	5.5	2.7	—

• [1193]

  TABLE 20
  PHOA ENZYMATIC ACTIVITYa(RELATIVE UNITS):
  PARENTAL CELLS VERSUS MINICELLS.

  	Cell typeb	Unlysed	Lysed, total	Lysed, membrane
  	Parent cell	—	358	240
  	Minicell	275	265	211
  	Minicell EQc	1,504	1,447	1,154

• These results suggest that co-expression induction of T-PhoA and minicells together results in minicells containing an equivalent amount of T-PhoA produced in both parental cells and minicells. However, the percent of T-PhoA compared to total protein is 3.5× greater in minicells than in parental cells. Furthermore, of the protein made, T-PhoA constitutes 50% of the total membrane protein in minicells, whereas it is only 29% in parental cells. It should be noted that the T-PhoA protein associated with the membrane can be easily removed by treatment with mild, non-ionic detergent suggesting that the T-PhoA present in the membrane pellet is indeed associated with the membrane and not an insoluble, co-sedimenting precipitate (data not shown). Finally, PhoA is a periplasmic enzyme that requires export to the periplasmic space for proper folding and disulfide bond formation. Both of which are required for enzymatic activity. In the time course of this experiment, expression of ΔPhoA lacking a leader sequence does not demonstrate enzymatic activity. Furthermore, there is no difference between unlysed and lysed minicells containing expressed T-PhoA (Table 20) also demonstrating that the PhoA enzyme domain of the T-PhoA chimera must be present in the periplasmic space. Therefore, the T-PhoA construct must membrane associate and the PhoA domain must orient into the periplasmic space for enzymatic activity. Thus, when comparing equivalent amounts of membrane lipid between parental cells and minicells in Table 20, membrane association-dependent T-PhoA activity is almost 5× greater than in parental cells. Taking into account the data in Table 19 where 50% of T-PhoA is in the membrane compared to 29% in parental cells, the difference in T-PhoA membrane association is not sufficient to explain the almost 5× increase in minicell activity. These observations suggest that minicells contain a capacity to support more expressed membrane protein than parental cells and that the protein that associates with the membrane is more active. This activity may be simply result from minicells allowing greater efficiency of folding and disulfide bond formation for this particular protein. However, do to the fact that minicells do not contain chromosome, it is also possible that the overexpression of this protein is readily finding membrane-binding sites in the absence of chromosomally produced competitors present in parental cells. Furthermore, overexpression of proteins often leads to increased protease expression. Because minicells do not contain chromosome, these otherwise degraded surplus T-PhoA is allowed the continued opportunity to insert and properly fold in the membrane, an attribute that could lend favor to overexpression of more complex membrane proteins.[1194]
Example 18Exemplary Methods to Induce and Study Complex Membrane Proteins
• Expression of non-native (exogenous) complex membrane proteins in bacterial systems can be difficult. Using the minicell system, we are able to eliminate toxicity issues. However, issues still remain with proper translation, compartmentalization at the membrane, insertion in the membrane and proper folding for native activity. To account for these potential problems we have constructed a modular chimeric system that incorporates leader sequences and chaperone-recognized soluble domains that are native to our bacterial minicell system. In addition, we created modular constructs that overexpress the native chaperones groESL and trigger factor (tig). Finally, we have constructed minicell-producing strains that contain mutations that effect protein export and disulfide bond formation. For non-limiting examples of these constructs see Table 21.[1195]

  TABLE 21
  NON-LIMITING TOOLS FOR EXOGENOUS COMPLEX
  PROTEIN SYNTHESIS AND FUNCTION

  		Residues of		SEQ ID
  Tool	Reference	sequence	Purpose	NO
  pMPX-5::phoA leader	—	1-48	Membrane	22
  			targeting
  pMPX-5::phoA leader	—	1-494	Membrane	23
  			targeting
  pMPX-5::malE leader	1	1-28	Membrane	24
  			targeting
  pMPX-5::malE leader	1	1-370	Membrane	25
  			targeting
  pMPX-17 (groESL, tig)	—	—	Chaperone	26
  pMPX-5::trxA::FLAG	2	2-109a	Solubility	27

• [1196]

  TABLE 22
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 21 CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  115	PhoA lead-1	GTCACGGCCGAGACTTATAGTCGC
  116	PhoA lead-2	GGTGTCCGGGCTTTTGTCACAGG
  117	PhoA lead-1-PstI	CGCGGCTGCAGATGTCACGGCCGAGACTTATAGTCGC
  118	PhoA lead-2-XbaI	CGCGGTCTAGATTCTGGTGTCCGGGCTTTTGTCACAGG
  119	PhoA complete	CAGCCCCAGAGCGGCTTCATGG
  120	PhoA complete-2-XbaI	CGCGGTCTAGATTTCAGCCCCAGAGCGGCTTTCATGG
  121	MalE lead-1	CGCGGCTGCAGATGAAAATAAAAACAGGTGCACGC
  		ATCCTCGCATTATCCGCATTAACGACGATGATGGTC
  		CCGCCTCGGCTCTCGCCAAAATCTCTAGACGCGG
  122	MalE lead-2	CCGCGTCTAGAGATTTTGGCGAGAGCCGAGGCGGAA
  		AACATCATCGTCGTTAATGCGGATAATGCGAGGATG
  		CGTGCACCTGTTTTTATTTTTCATCTGCAGCCGCG
  123	MalE-1	GGTGCACGCATCCTCGCATTATCCGC
  124	MalE-2	CGGCATACCAGAAAGCGGACATCTGC
  125	MalE-1-PstI	CGCGGCTGCAGATGAAAATAAAAACAGGTGCACGC
  		ATCCTCGCATTATCCGC
  126	MalE-2-XbaI	CGCGGTCTAGAACGCACGGCATACCAGAAAGCGGA
  		CATCTGC
  127	Tig-1	CGCGACAGCGCGCAATAACCGTTCTCG
  128	Tig-2	GCTGGTTCATCAGCTCGTTGAAAGTGG
  129	Tig-1-NarI	GCGCCGGCGCCATACGCGACAGCGCGCAATAACCGT
  		TCTCG
  130	Tig-2-XbaI	GGCGCTCTAGATTATTATTACGCCTGCTGGTTCATCA
  		GCTCGTTGAAAGTGG
  131	Gro-1	GGTAGCACAATCAGATTCGCTTATGACGG
  132	Gro-2	GCCGCCCATGCCACCCATGCCGCCC
  133	Gro-1-XbaI	GCGTCTAGAGGTAGCACAATCAGATTCGCTTATGAC
  		GG
  134	Gro-2-HindIII	GGCGCAAGCTTATTATTACATCATGCCGCCCATGCC
  		AGCCATGCCGCCC
  135	TrxA-1	GCGATAAAATTATTCACCTGACTGACG
  136	TrxA-2	GCGTCGAGGAACTCTTTCAACTGACC
  137	TrxA-1-Fxa-PstI	CGCGGCTGCAGATGATCGAAGCCCGCTCTAGACTCG
  		AGAGCGATAAAATTATTCACCTGACTGACG
  138	TrxA-2-FLAG-BamHI	CCGCGGGATCCTTATTAATCATCATGATCTTTATAAT
  		CGCCATCATGATCTTTATAATCCTCGAGCGCCAGGTT
  		AGCGTCGAGGAACTCTTTCAACTGACC

• Oligonucleotides SEQ ID NOS.:115, 116, 117 and 118 were used to amplify the phoA leader (residues 1-49) from[1197]E. colichromosomal DNA. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using PstI and XbaI to create SEQ ID NO.:22.
• Oligonucleotides SEQ ID NOS.:115, 117, 119 and 120 were used to amplify the complete phoA gene from[1198]E. colichromosomal DNA. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using PstI and XbaI to create SEQ ID NO.23.
• Oligonucleotides SEQ ID NOS.:121 and 122 were used to construct the malE leader (residues 1-28) sequence. Once annealed, this construct was inserted into SEQ ID NO.: 6 (pMPX-5) using PstI and XbaI to create SEQ ID NO.:24.[1199]
• Oligonucleotides SEQ ID NOS.:123, 124, 125 and 126 were used to amplify the malE expanded leader (residues 1-370) from[1200]E. colichromosomal DNA. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using PstI and XbaI to create SEQ ID NO.:25.
• Oligonucleotides SEQ ID NOS.:127, 128, 129 and 130 were used to amplify the tig control and gene region from[1201]E. colichromosomal DNA. Once amplified, this region was ligated to the groESL amplified region below using XbaI prior to insertion into SEQ ID NO.: 6 (pMPX-5) using NarI (from the tig region) and HindIII (from the groESL region) to create SEQ ID NO.:26.
• Oligonucleotides SEQ ID NOS.:131, 132, 133 and 134 were used to amplify the groESL control and gene region from[1202]E. colichromosomal DNA. Once amplified, this region was ligated to the tig amplified region above using XbaI prior to insertion into SEQ ID NO.: 6 (pMPX-5) using NarI (from the tig region) and HindIII (from the groESL region) to create SEQ ID NO.:26.
• Oligonucleotides SEQ ID NOS.:135, 136, 137 and 138 were used to amplify trxA (residues 2-109) from[1203]E. colichromosomal DNA and insert FLAG and Factor Xa sequences. Once amplified, this region was inserted into SEQ ID NO.: 6 (pMPX-5) using PstI and BamHI to create SEQ ID NO.:27.
• By way of non-limiting example, the pMPX-5::phoA leader (residues 1-48), pMPX-5::phoA leader (residues 1-494), pMPX-5::malE leader (residues 1-28), and pMPX-5::malE leader (residues 1-370) constructs are designed to direct expressed exogenous membrane proteins to the minicell cytoplasmic membrane. In addition to these constructs, By way of non-limiting example, mutations in[1204]E. coligenes secA and secY, specifically mutation prlA4 (Strader, J., et al. 1986. Kinetic analysis of lamb mutants suggests the signal sequence plays multiple roles in protein export. J. Biol. Chem. 261:15075-15080), permit promiscuous targeting to the membrane. These mutations, like the above constructs are integrated into the minicell expression system. To complement these mutations, the chaperone complex groESL and trigger factor have also been incorporated into the expression system. By way of non-limiting example, pMPX-5::trxA::FLAG will be used to create a carboxy-terminal fusion to the protein of interest to increase the membrane insertion efficiency of the membrane protein of interest (Tucker, J., and R. Grisshammer. 1996. Purification of a rat neurotensin receptor expressed inEscherichia coli.Biochem. J. 317:891-899). Also By way of non-limiting example, pMPX-5::FLAG::toxR and pMPX-5::FLAG::λcI constructs will be prepared to create a carboxy-terminal fusion to the protein of interest for use in a reporter-based assay for protein-protein interactions. By way of non-limiting example, the protein of interest for this system is a GPCR. Also By way of non-limiting example, this GPCR may be the neurotensin receptor from rat (Grisshammer, R., et al. 1993. Expression of a rat neurotensin receptor inEscherichia coli.Biochem. J. 295:571-576.), or the β2 adrenergic receptor from humans (Freissmuth, M., et al. 1991. Expression of two β-adrenergic receptors inEscherichia coli:functional interaction with two forms of the stimulatory G protein. Proc. Natl. Acad. Sci. 88:8548-8552). Insertion of a GPCR into one of these reporter constructs creates a carboxy-terminal fusion between the GPCR of interest and the DNA-binding regulatory domain of the ToxR positive activator, the λcI repressor, or the AraC positive activator. To complete this reporter system, By way of non-limiting example pMPX-5::(X)::toxR or pMPX-5::(X)::λcI will be used to create a carboxy-terminal fusion to the protein of interest for use in a reporter-based assay for protein-protein interactions, where (X) may be any protein or molecule involved in an intermolecular or intramolecular interaction. By way of non-limiting example, this molecule of interest may be a G-protein. This G-protein may be the Gα_i1-protein from rat (Grisshammer, R., and E. Hermans. 2001. Functional coupling with Gαq and Gαi1 protein subunits promotes high-affinity agonist binding to the neurotensin receptor NTS-1 expressed inEscherichia coli.FEBS Lett. 493:101-105), or the G_sα-protein from human (Freissmuth, M., et al. 1991. Expression of two β-adrenergic receptors inEscherichia coli:functional interaction with two forms of the stimulatory G protein. Proc. Natl. Acad. Sci. 88:8548-8552). Like the GPCR, insertion of a G-protein into one of these reporter constructs creates a carboxy-terminal fusion between the G-protein of interest and the DNA-binding regulatory domain of the ToxR positive activator, the λcI repressor, or other regulatory protein. Finally, these plasmid constructs contain the DNA-binding domain of each regulator; the ctx regulatory region fromVibrio cholerae(Russ, W. P., and D. M. Engelman. 1999. TOXCAT: a measure of transmembrane helix association in a biological membrane. 96:863-868), or the P_R1O_R1 region of bacteriophage lambda (Hu, J. C., et al. 1990. Sequence requirements for coiled-coils: analysis with lambda repressor-GCN4 leucine zipper fusions. Science. 250:1400-1403), respectively. By way of non-limiting example, each binding domain is coupled to a reporter sequence encoding luciferase (Dunlap, P. V., and E. P. Greenberg. 1988. Control ofVibrio fischerilux gene transcription by a cyclic AMP receptor protein-luxR protein regulatory circuit. J. Bacteriol. 170:4040-4046), green fluorescent protein (GFP) (Yang, T. T., et al. 1996. Dual color microscopic imagery of cells expressing the green fluorescent protein and a red-shifted variant. Gene. 173:19-23; Matthysse, A. G., et al. 1996. Construction of GFP vectors for use in gram-negative bacteria other thanEscherichia coli.FEMS Microbiol. Lett. 145:87-94), or other reporter. Co-expression of these GPCR and G-protein chimeras will create a system measuring the interaction between a GPCR and G-protein within an intact minicell. This system is designed to be used as a positive or negative read-out assay and may be used to detect loss or gain of GPCR function. Although the GPCR-G-protein interaction is provided as an example, this modular system may be employed with any soluble or membrane protein system measuring protein-protein or other intermolecular interaction.
Example 19Exemplary Methods for Gene Transfer Using Minicells or Minicell Protoplasts
• Included in the design of the invention is the use of minicells to transfer genetic information to a recipient cell. By way of non-limiting example, this gene transfer may occur between a minicell and a mammalian cell in vitro, or in vivo, and this gene transfer may occur through cell-specific interactions, through general interactions, or a combination of each. To accomplish this task three basic constructs were created. Each of these constructs is created in pMPX-6 which contains a CMV promotor controlling the synthesis of GFP. The plasmid pMPX-6 was constructed by cloning the araC through the multiple cloning site of pBAD24 into pEGFP (Clontech). This construct provided a bacterial regulator as well as a method to monitor the success of gene transfer using GFP expression form the CMV promotor. In design, the protein expressed using the bacterial promotor will drive the cell-cell interaction, while the successful transfer of DNA from the minicell to the recipient cell will initiate the production of GFP. By way of non-limiting example, proteins that will drive the cell-cell interaction may be the invasin protein from[1205]Yersinia pseudotuberculosis,which stimulates β1 integrin-dependent endocytic events. To properly display the invasin protein on the surface of minicells, the domain of invasin that stimulates these events (residues 490-986) (Dersch, P., and R. R. Isberg. 1999. A region of theYersinia pseudotuberculosisinvasin protein enhances integrin-mediated uptake into mammalian cells and promotes self-association. EMBO J. 18:1199-1213) was fused to the transmembrane domain of ToxR. Expression of this construct from pMPX-6 will display T-Inv on the surface of the minicell and stimulate endocytosis with any cell displaying a β1 integrin. Thus, T-Inv display will provide a general mechanism of gene transfer from minicells. To provide specificity, By way of non-limiting example, the ligand portion of epidermal growth factor (EGF) may be fused to the transmembrane domain of ToxR, thus creating a protein that will interact with cells displaying the EGF receptor (EGFR). Likewise, tumor nucrosis factor (TNF) may also serve this purpose by stimulating cell-cell interactions between minicells displaying TNF and cells displaying TNF receptor (TNFR). Although EGF-EGFR and TNF-TNFR interactions may stimulate cell-cell fusion between minicells and recipient cells, or minicell uptake, this alone may not be sufficient to efficiently transfer genetic information from minicells. Therefore, a genetic approach to increasing the cell-cell genetic transfer may be the development of a genetic switch that senses the specificity interaction, e.g. EGF-EGFR interaction, and turns on the production of a second gene product, e.g. invasin, that stimulates the endocytic event. By way of non-limiting example, this genetic switch may be similar to the GPCR-G-protein interaction reporter system above, in that an extracellular event stimulates the dimerization of a transcriptional active regulator, thus turning on the production of invasin or invasin-like protein. In either approach, the display system to stimulate transfer of genetic information from minicells to recipient cells may also be applicable to the transfer of substances other than genetic information, e.g. pre-synthesized therapeutic drugs.
• To test this targeting methodology, different pMPX-6 constructs containing each of these general or specific cell-cell interaction proteins will be transformed into a minicell producing strain and either by co-expression induction of minicells, by post-minicell purification induction, or by post-protoplasting induction, minicells displaying the targeting protein of interest will be produced. When using the co-expression induction and post-minicell purification induction of the targeting protein approaches, it is necessary to protoplast the purified minicells after protein induction. Once the targeting protein has been displayed on the surface of a minicell protoplast, these protoplasts are ready to be exposed to target cells. For preliminary experiments these interactions will be monitored using cell culture of Cos cells in comparison to lipofectamine (Invitrogen), electroporation, and other transfection techniques. Initial experiments will expose protoplasts displaying T-Inv to Cos cells and compare the transfection efficiency to protoplast containing pMPX-6::t-inv in the absence of t-inv expression, naked pMPX-6::t-inv alone, and naked pMPX-6::t-inv with lipofectamine. Each of these events will be monitored using fluorescent microscopy and/or flow cytometry. From these results the specific targeting apparatus proteins will be tested. Using A-431 (display EGFR) and K-562 (no EGFR) cell lines, the pMPX-6::t-egf constructs will be tested. Using the same approaches as for the t-inv study, the level of transfection between A-431 and K-562 cell lines will be measured and compared to those achieved using lipofectamine. Similarly, the ability of TNF to stimulate gene transfer will be studied using L-929 cells. In all cases, the ability of these general and specific targeting protein constructs will be compared to standard transfection techniques. Upon positive results, these methodologies will be tested on difficult to transfect cell lines, e.g. adult cardiomyocytes. The basis of these results will create a foundation for which applications into in vivo gene transfer may occur.[1206]
Example 20Additional and Optimized Methods for Genetic Expression
• Expression in minicells may occur following purification of minicells and/or minicell protoplasts from parental cells and LPS constituents, respectively. However, for some applications it is preferred to co-express proteins of interest with minicell induction. For these approaches, one may use the protocol described in Example 13 for expression of the phoA constructs. Either of these approaches may be accomplished using one or more of the following expression constructs (Table 23) and/or optimized expression constructs (Table 25).[1207]
• Expression plasmid pCGV1 contains a temperature sensitive lambda cI repressor (cI857) and both lambda PR and PL promoters (Guzman, C. A., et al. 1994. A novel[1208]Escherichia coliexpression-export vector containing alkaline phosphatase as an insertional inactivation screening system. Gene. 148:171-172) with an atpE initiation region (Schauder, B., et al. 1987. Inducible expression vectors incorporating theEscherichia coliatpE translational initiation region. Gene. 52:279-283). Included in the design of the invention is the modification of this expression vector to best align the required Shine-Delgarno ribosomal binding site with cloning sites. In addition, the pCGVI expression vector was modified to incorporate a stem-loop structure at the 3-prime end of the transcript in order to provide a strong transcriptional stop sequence (Table 23).
• Expression plasmid pCL478 contains a temperature sensitive lambda cI repressor (cI857) and both lambda PR and PL promoters (Love, C. A., et al. 1996. Stable high-copy bacteriophage promoter vectors for overproduction of proteins in[1209]Escherichia coli.Gene. 176:49-53). Included in the design of the invention is the modification of this expression vector to best align the required Shine-Delgarno ribosomal binding site with cloning sites. In addition, the pCL478 expression vector was modified to incorporate a stem-loop structure at the 3-prime end of the transcript in order to provide a strong transcriptional stop sequence (Table 23).

  TABLE 23
  LAMBDA CI857 EXPRESSION VECTOR MODIFICATIONS

  New	Parent	Region
  Plasmid	plasmid	removed	Region addeda	SEQ ID NO
  pMPX-84	pCGV1	NdeI - BamHI	NdeI, SD - PstI, XbaI, KpnI, Stem-loop, BamHI	139
  pMPX-85	pCGV1	NdeI - BamHI	NdeI, SD - SalI, XbaI, KpnI, Stem-loop, BamHI	140
  pMPX-86	pCL478	BamHI - XhoI	BamHI, SD - PstI, XbaI, KpnI, Stem-loop, XhoI	141
  pMPX-87	pCL478	BamHI - XhoI	BamHI, SD - SalI, XbaI, KpnI, Stem-loop, XhoI	142

• [1210]

  TABLE 24
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 23

  SEQ ID NO	Primer name	5′ to 3′ sequence

  143	CGV1-1-SalI	TATGTAAGGAGGTTGTCGACCGGCTCAGTCTAGAGGTACCCGCCCTCATCCGAAAGGGCGTATTG
  144	CGV1-2-SalI	GATCCAATACGCCCTTTCGGATGAGGGCGGGTACCTCTAGACTGAGCCGGTCGACAACCTCCTTACA
  145	CGV1-1-PstI	TATGTAAGGAGGTTCTGCAGCGGCTCAGTCTAGAGGTACCCGCCCTCATCCGAAAGGGCGTATTG
  146	CGV1-2-PstI	GATCCAATACGCCCTTTCGGATGAGGGCGGGTACCTCTAGACTGAGCCGCTGCAGAACCTCCTTACA
  147	CL478-1-SalI	GATCCTAAGGAGGTTGTCGACCGGCTCAGTCTAGAGGTACCCGCCCTCATCCGAAAGGGCGTATTC
  148	CL478-2-SalI	TCGAGAATACGCCCTTTCGGATGAGGGCGGGTACCTCTAGACTGAGCCGGTCGACAACCTCCTTAG
  149	CL478-1-PstI	GATCCTAAGGAGGTTCTGCAGCGGCTCAGTCTAGAGGTACCCGCCCTCATCCGAAAGGGCGTATTC
  150	CL478-2-PstI	TCGAGAATACGCCCTTTCGGATGAGGGCGGGTACCTCTAGACTGAGCCGCTGCAGAACCTCCTTAG

• Oligonucleoides SEQ ID NOS.: 143 and 144 were annealed to each other to generate a DNA molecule with a 5′ overhang at both ends. The overhangs are designed so that the DNA can be directly cloned into pCGVI cut with NdeI (5′ overhang is TA) and BamHI (5′ overhang is GATC). Insertion of the annealed DNA into pCGVI creates SEQ ID NO.: 139, pMPX-84.[1211]
• Oligonucleoides SEQ ID NOS.: 145 and 146 were annealed to each other to generate a DNA molecule with a 5′ overhang at both ends. The overhangs are designed so that the DNA can be directly cloned into pCGVI cut with NdeI (5′ overhang is TA) and BamHI (5′ overhang is GATC). Insertion of the annealed DNA into pCGVI creates SEQ ID NO.: 140, pMPX-85.[1212]
• Oligonucleoides SEQ ID NOS.: 147 and 148 were annealed to each other to generate a DNA molecule with a 5′ overhang at both ends. The overhangs are designed so that the DNA can be directly cloned into pCL478 cut with BamHI (5′ overlap is GATC) and XhoI (overhang is TCGA). Insertion of the annealed DNA into pCL578 cut with BamHI and XhoI creates SEQ ID NO.: 141, pMPX-86.[1213]
• Oligonucleoides SEQ ID NOS.: 149 and 150 were annealed to were annealed to each other to generate a DNA molecule with a 5′ overhang at both ends. The overhangs are designed so that the DNA can be directly cloned into pCL578 cut with BamHI (5′ overlap is GATC) and XhoI (overhang is TCGA). Insertion of the annealed DNA into pCL478 cut with BamHI and XhoI creates SEQ ID NO.: 142, pMPX-87.[1214]
• The optimized expression constructs in Table 25 were created from SEQ ID NOS.: 6, 11, and 12 (see Table 13). Modifications were made to optimize the alignment of the SalI or PstI cloning sites with the Shine-Delgarno ribosome-binding site. In addition, stem-loop transcriptional termination sequences were added on the 3′ end of the cloning region.[1215]

  TABLE 25
  EXPRESSION CONSTRUCTS

  Plasmid	Regulatory element(s)	inducer	Plasmid	SEQ ID NO.:
  pMPX-67	RhaRS	Rhamnose	PUC-18	151
  pMPX-72	RhaRS	Rhamnose	PUC-18	152
  pMPX-66	AraC	Arabinose	PUC-18	153
  pMPX-71	AraC	Arabinose	PUC-18	154
  pMPX-68	MelR	Melibiose	PUC-18	155

• [1216]

  TABLE 26
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 25
  CONSTRUCTS

  SEQ ID NO.:	Primer name	5′ to 3′ sequence

  69	Rha-1	GCGAATTGAGATGACGCCACTGGC
  156	Rha-SD	GCAGAACCTCCTGAATTTCATTACGACC
  71	Rha-1-HindIII	CGGCGAAGCTTAATTAATCTTTCTGCGAATTGAGATGACGCCACTGGC
  157	Rha-SD SalI	CCGCGGGTACCAATACGCCCTTTCGGATGAGGGCGCGGGG
  	KpnI	ATCCTCTAGAGTCGACGTCGACAACCTCCTGAATTTCATTACGACC
  158	Rha-SD KpnI	CCGCGGGTACCAATACGCCCTTTCGGATGAGGGCGCGGGG
  	KpnI	ATCCTCTAGAGTCGACCTGCAGAACCTCCTGAATTTCATTACGACC
  81	Ara-1	CAAGCCGTCAATTGTCTGATTCG
  159	Ara-SD	CTGCAGGGCCTCCTGCTAGCCCAAAAAAACGGGTATGG
  83	Ara-1-HindIII	GCGCCAAGCTTCAAGCCGTCAATTGTCTGATTCG
  160	Ara-SD SalI	CCGCGGGTACCAATACGCCCTTTCGGATGAGGGCGCGGGG
  	KpnI	ATCCTCTAGAGTCGACGTCGACGGCCTCCTGCTAGCCCAAAAAAACGGGTATGG
  161	Ara-SD PstI	CCGCGGGTACCAATACGCCCTTTCGGATGAGGGCGCGGGG
  	KpnI	ATCCTCTAGAGTCGACCTGCAGGGCCTCCTGCTAGCCCAAAAAAACGGGTATGG
  77	Mel-1	CGTCTTTAGCCGGGAAACG
  162	Mel-SD	CCTCCTGGCTTGCTTGAATAACTTCATCATGG
  79	Mel-1-HindIII	GCCGCAAGCTTCGTCTTTAGCCGGGAAACG
  163	Mel-SD-SalI	CCGCGGGTACCAATACGCCCTTTCGGATGAGGGCGCGGGG
  	KpnI	ATCCTCTAGAGTCGACCCCCTCCTGGCTTGCTTGAATAACTTCATCATGGC

• Oligonucleotides SEQ ID NOS.: 69, 156, 72, and 157 were used to amplify the rhaRS genes and their divergent control region from the[1217]E. colichromosome and insertion of an optimized SalI-Shine-Delgarno ribosome-binding alignment and a stem-loop transcriptional termination sequence. Once amplified, this region was inserted into pUC18 using HindIII and KpnI to create pMPX67, SEQ ID NO.: 151.
• Oligonucleotides SEQ ID NOS.: 69, 156, 72, and 158 were used to amplify the rhaRS genes and their divergent control region from the[1218]E. colichromosome and insertion of an optimized PstI-Shine-Delgarno ribosome-binding alignment and a stem-loop transcriptional termination sequence. Once amplified, this region was inserted into pUC 18 using HindIII and KpnI to create, pMPX-72, SEQ ID NO.: 152.
• Oligonucleotides SEQ ID NOS.: 81, 159, 81, 160 were used to amplify the araC genes and their divergent control region from the[1219]E. colichromosome and insertion of an optimized SalI-Shine-Delgarno ribosome-binding alignment and a stem-loop transcriptional termination sequence. Once amplified, this region was inserted into pUC18 using HindIII and KpnI to create, pMPX-66, SEQ ID NO.: 153.
• Oligonucleotides SEQ ID NOS.: 81, 159, 81, 161 were used to amplify the araC genes and their divergent control region from the[1220]E. colichromosome and insertion of an optimized PstI-Shine-Delgarno ribosome-binding alignment and a stem-loop transcriptional termination sequence. Once amplified, this region was inserted into pUC 18 using HindIII and KpnI to create, pMPX-71, SEQ ID NO.: 154.
• Oligonucleotides SEQ ID NOS.: 77, 162, 79, 163 were used to amplify the melR genes and their divergent control region from the[1221]E. colichromosome and insertion of an optimized SalI-Shine-Delgarno ribosome-binding alignment and a stem-loop transcriptional termination sequence. Once amplified, this region was inserted into pUC18 using HindIII and KpnI to create, pMPX-68, SEQ ID NO.: 155.
EXAMPLE 21Optimization of Rat Neurotensin Receptor (NTR) Expression
• Expression of specific GPCR proteins in minicells may require chimeric domain fusions to stabilize the expressed protein and/or direct the synthesized protein to the membrane. The NTR protein from rat was cloned into several chimeric combinations to assist in NTR expression and membrane association (Grisshammer, R., et al. 1993. Expression of a rat neurotensin receptor in[1222]Escherichia coli.Biochem. J. 295:571-576; Tucker, J., and Grisshammer, R. 1996. Purification of a rat neurotensin receptor expressed inEscherichia coli.Biochem. J. 317:891-899). Methods for construction are shown the Tables below.

  TABLE 27
  NEUROTENSIN RECEPTOR EXPRESSION FACILITATING
  CONSTRUCTS

  		SEQ ID
  Proteina	Constructb	NO
  MalE(L)	SalI-MalE(1-370)-Factor Xa-NTR	164
  homology
  NTR	Factor Xa-NTR(43-424)-NotI-	165
  	FLAG- KpnI
  MalE(L)-NTR	SalI-MalE(1-370)-Factor Xa-NTR	166
  	(43-424)-NotI-FLAG-KpnI
  MalE(S)-NTR	SalI-MalE(1-28)-Factor Xa-NTR(43-	167
  424)-NotI-FLAG-KpnI
  TrxA	NotI-TrxA(2-109)-NotI	168
  MalE(L)-NTR-TrxA	SalI-MalE(1-370)-Factor Xa-NTR	169
  	(43-424)-NotI-TrxA(2-109)-FLAG-
  	KpnI
  MalE(S)-NTR-TrxA	SalI-MalE(1-28)-Factor Xa-NTR(43-	170
  	424)-NotI-TrxA(2-109)-FLAG-KpnI

• [1223]

  TABLE 28
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 27

  SEQ ID
  NO.:	Primer name	5′ to 3′ sequence

  171	MalE-1	GGTGCACGCATCCTCGCATTATCCGC
  172	MalE-2	CGCACGGCATACCAGAAAGCGGACATCTGCG
  173	MalE-1-SalI	CCGCGGTCGACATGAAAATAAAAACAGGTGCACGCATCCTCGC
  174	MalE-2-XaNTR GCCGTGTCGGATTCCGAGGTGCGGCCTTCGATACGCACGGCATACCAAGAAAGCGGGATGTTCGGC
  175	NTR-1	CCTCGGAATCCGACACGGCAGGGC
  176	NTR-2	GTACAGGGTCTCCCGGGTGGCGCTGG
  177	NTR-1-Xa	CCGCGATCGAAGGCCGCACCTCGGAATCCGACACGGCAGGGCC
  178	NTR-2-Flag	GGGGCGGTACCTTTGTCATCGTCATCTTTATAATCTGCGGCCGC
  		GTACAGGGTCTCCCGGGTGGCGCTGGTGG
  179	NTR-2-Stop Kpn-I	GCGGCGGTACCTTATTATTTGTCATCGTCATCTTTATAATCTGCGGCCGCG
  180	NTR-1-Xa Lead	CCGCATTAACGACGATGATGTTTTCCGCCTCGGCTCTCGCCAAA
  		ATCATCGAAGGCCGCACCTCGGAATCCGACACGGC
  181	NTR-2-Lead2 SalI	CCGCGGTCGACATGAAAATAAAAACAGGTGCACGCATCCTCGC
  		ATTATCCGCATTAACGACGATGATGTTTTCGGCCTCGGC
  182	TrxA-1	CCGCGAGCGATAAAATTATTCACCTGACTGACG
  183	TrxA-2	GCCCGCCAGGTTAGCGTCGAGGAACTCTTTCAACTGACC
  184	TrxA-1-NotI	GCGGCCGCAAGCGATAAAATTATTCACCTGACTGACG
  185	TrxA-2-Notl	GGCGCTGCGGCCGCATCATCATGATCTTTATAATCGCC

• Oligonucleotides SEQ ID NOS.: 171, 172, 173 and 174 were used to amplify malE residues 1-370 from the[1224]E. colichromosome to create SEQ ID NO.: 164. Using overlap PCR with the extended NTR homology, a chimeric translational fusion was made between MalE (1-370) and NTR residues 43-424 (SEQ ID NO.: 165) to create a SEQ ID NO.: 166. SEQ ID NO.: 166 was cloned into plasmids pMPX-85, pMPX-87, pMPX-66 and pMPX-67 (respectively, SEQ ID NOS.: 140, 142, 151 and 153) using SalI and KpnI.
• Three-step PCR with oligonucleotides, SEQ ID NOS.: 175 and 176 as primers was used to amplify NTR residues 43-424 from rat brain cDNA. SEQ ID NOS.: 177 and 178 were then used with the NTR (43-424) template to add factor Xa and FLAG sequence. Finally, SEQ ID NOS.: 177 and 179 were used to add a KpnI site to create SEQ ID NO.: 165. Using overlap PCR with malE(1-370) containing extended NTR homology, a chimeric translational fusion was made between NTR (43-424) and MalE (1-370) (SEQ ID NO.: 164) to create a SEQ ID NO.: 166. SEQ ID NO.: 166 was cloned into SEQ ID NOS.: 140, 142, 151 and 153 using SalI and KpnI.[1225]
• Using three-step PCR oligonucleotides SEQ ID NOS.: 175 and 176 were first used to amplify NTR residues 43-424 from rat brain cDNA. SEQ ID NOS.: 178 and 180 were then used with the NTR (43-424) template to add factor Xa and FLAG sequence. Finally, SEQ ID NOS.: 179 and 181 were used to add KpnI to create SEQ ID NO.: 167. SEQ ID NO.: 167 was cloned into SEQ ID NOS.: 140, 142, 151 and 153 using SalI and KpnI.[1226]
• Oligonucleotides SEQ ID NOS.: 182, 183, 184 and 185 were used to amplify TrxA residues 2-109 from the[1227]E. colichromosome to create SEQ ID NO.: 168. Using NotI, TrxA residues 2-109 was cloned into SEQ ID NOS.: 166 and 167 to create SEQ ID NOS.: 169 and 170, respectively. SEQ ID NO.: 169 and 170 were cloned into SEQ ID NOS.: 140, 142, 151 and 153 using SalI and KpnI.
EXAMPLE 22Methods for Functional GPCR Assay
• Functional G-protein-coupled receptor (GPCR) binding assays in minicells requires expression of a GPCR of interest into the minicell membrane bilayer and cytoplasmic expression of the required G-protein. For these purposes, constructs were created to co-express both a GPCR and a G-protein. To regulate the ratio of GPCR to G-protein, transcriptional fusions were created. In these constructs, the GPCR and G-protein are co-transcribed as a bi-cistronic mRNA. To measure the GPCR-G-protein interaction in the intact minicell, each protein was created as a chimera with a transactivation domain. For these studies the N-terminal DNA-binding, activation domain of the ToxR protein from[1228]V. choleraewas fused to the C-terminus of both the GPCR and G-protein. Finally, to measure the interaction GPCR-G-protein interaction, the ToxR-activated ctx promoter region was cloned in front of lacZ. Dimerization of the ToxR DNA-binding region will bind and activate the ctx promoter. In this construct, heterodimerization of the GPCR and G-protein will promote dimerization of ToxR that will be monitored by LacZ expression. Details of these constructs are shown in Table 29.

  TABLE 29
  FUNCTIONAL HUMAN GPCR CONSTRUCTS

  		SEQ ID
  Proteina,b	Constructa,b	NO.:
  β2AR	SalI-β2AR-PstI, XhoI	186
  GS1α	XhoI-GS1α-XbaI	187
  β2AR-GS1α fusion	SalI-β2AR-PstI, XhoI-GS1α-XbaI	188
  β2AR-stop	SalI-β2AR-PstI-Stop-SD-XhoI	189
  β2AR-stop-GS1α	SalI-β2AR-PstI-Stop-SD-XhoI-GS1α-	190
  	XbaI
  ToxR	ClaI-ToxR-XbaI	191
  GS1α	XhoI-GS1α-ClaI	192
  GS2α	XhoI-GS2α-ClaI	193
  Gαq	XhoI-Gqα-ClaI	194
  Giα	XhoI-Giα-ClaI	195
  Gα12/13	XhoI-Gα12/13-ClaI	196
  GS1α-ToxR	XhoI-GS1α-ClaI-ToxR-XbaI	197
  GS2α-ToxR	XhoI-GS2α-ClaI-ToxR-XbaI	198
  Gαq-ToxR	XhoI-Gαq-ClaI-ToxR-XbaI	199
  Giα-ToxR	XhoI-Giα-ClaI-ToxR-XbaI	200
  Gα12/13-ToxR	XhoI-Gα12/13-ClaI-ToxR-XbaI	201
  ToxR	PstI-ToxR-XhoI	202
  β2AR	SalI-β2AR-PstI	203
  β2AR-ToxR	SalI-β2AR-PstI-ToxR-Stop-SD-XhoI	204
  β2AR-ToxR-stop-	SalI-β2AR-PstI-ToxR-Stop-SD-XhoI-	205
  GS1α-ToxR	GS1α-ClaI-ToxR-XbaI
  Pctx	XbaI-Pctx-lacZ homology	206
  lacZ	Pctx homology-lacZ-XbaI	207
  Pctx::lacZ	XbaI-Pctx-lacZ-XbaI	208

• [1229]

  TABLE 30
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 29.

  SEQ ID
  NO.:	Primer name	5′ to 3′ sequence

  209	β2AR-1	GGGGCAACCCGGGAACGGCAGCGCC
  210	β2AR-2	GCAGTGAGTCATTTGTACTACAATTCCTCC
  211	β2AR-1-SalI	CGCGGTCGACATGGGGCAACCCGGGAACGGCAGCGCC
  212	β2AR-2-Link-	GGCTCGAGCTGCAGGTTGGTGACCGTCTGGCCACGCTC
  		XhoI	TAGCAGTGAGTCATTTGTACTACAATTCC
  213	GS1α-1	GGGCTGCCTCGGGAACAGTAAGACCGAGG
  214	GS1α-2	GAGCAGCTCGTACTGACGAAGGTGCATGC
  215	GS1α- 1-XhoI	GGAGGCCCTCGAGATGGGCTGCCTCGGGAACAGTAAGACCGAGG
  216	GS1α-2-XbaI	CCTCTAGATTATTATCGATGAGCAGCTCGTACTGACGAAGGTGCATGC
  217	GS1α-2-ClaI	CCATCGATGAGCAGCTCGTACTGACGAAGGTGCATGC
  218	Gα12-1	CCGGGGTGGTGCGGACCCTCAGCCGC
  219	Gα12-2	CTGCAGCATGATGTCCTTCAGGTTCTCC
  220	Gα12-1-XhoI	GCGGGCTCGAGATGTCCGGGGTGGTGCGGACCCTCAGCCGC
  221	Gα12-2-ClaI	GCGCCATCGATCTGCAGCATGATGTCCTTCAGGTTCTCC
  222	Gαq-1	GACTCTGGAGTCCATCATGGCGTGCTGC
  223	Gαq-2	CCAGATTGTACTCCTTCAGGTTCAACTGG
  224	Gαq-1-XhoI	ATGACTCTGGAGTCCATCATGGCGTGCTGC
  225	Gαq-2-ClaI GCGCCATCGATGACCAGATTGTACTCCTTCAGGTTCAACTGG
  226	Giα-1	GGGCTGCACCGTGAGCGCCGAGGACAAGG
  227	Giα-2	CCTTCAGGTTGTTCTTGATGATGACATCGG
  228	Giα-1-XhoI	ATGGGCTGCACCGTGAGCGCCGAGGACAAGG
  229	Giα-2-ClaI	GCGCCATCGATGAAGAGGCCGCAGTCCTTCAGGTTGTTCTTGATGATGACATCGG
  230	GS2α-1	GGGCTGCCTCGGGAACAGTAAGACCGAGG
  231	GS2α-2	GAGCAGCTCGTACTGACGAAGGTGCATGC
  232	GS2α-1-XhoI	ATGGGCTGCCTCGGGAACAGTAAGACCGAGG
  233	GS2α-2-ClaI	GCGCCATCGATGAGCAGCTCGTACTGACGAAGGTGCATGC
  234	β2AR-2-Link-	GGCTCGAGGGCCTCCTTGATTATTACTCGAGGGCCTCC
  	Stop-XhoI	TTGATTATTACTGCAGGTTGGTGACCGTCTGGCCACGCTCTAGCAGTGAGTCATTTGTACTACAATTCC
  235	β2AR-2-Link	CCCTGCAGGTTGGTGACCGTCTGGCCACGCTCTAGCAGTGAGTCATTTGTACTACAATTCC
  236	Tox (5-141)-1B	GGACACAACTCAAAAGAGATATCGATGAGTCATATTGG
  237	Tox (5-141)-2	GAGATGTCATGAGCAGCTTCGTTTTCGCG
  238	Tox (5-141)-1-	GCGTGGCCAGACGGTCACCAACCTGCAGGGACACAAC
  	Link	TCAAAAGAGATATCG
  239	Tox (5-141)-2-	CGGGGATCCTCTAGATTATTAAGAGATGTCATGAGCAG
  	XhoI	CTTCGTTTTCGGG
  240	Ctx-1	GGCTGTGGGTAGAAGTGAAACGGGGTTTACCG
  241	Ctx-2	CTTTACCATATAATGCTCCCTTTGTTTAACAG
  242	Ctx-2-XbaI	CGCGGTCTAGAGGCTGTGGGTAGAAGTGAAACGGGGTTTACCG
  243	Ctx-2-LacZ	CGACGGCCAGTGAATCCGTAATCATGGTCTTTACCATATAATGCTCCCTTTGTTTAACAG
  244	LacZ-1	CCATGATTACGGATTCACTGGCCGTCG
  245	LacZ-2	CCAGACCAACTGGTAATGGTAGCGACC
  246	LacZ-1-Ctx	GGTAAAGACCATGATTACGGATTCACTGGCCGTCG
  247	LacZ-2-XbaI	GCGCCTCTAGAAATACGCCCTTTCGGATGAGGGCGTT
  		ATTATTTTTGACACCAGACCAACTGGTAATGGTAGCGACC

• Oligonucleotides SEQ ID NOS.: 209, 210, 211 and 212 were used to amplify human β2AR from human cDNA to create SEQ ID NO.: 186. Using SalI and XhoI a translational fusion was made between β2AR and human GS1α (SEQ ID NO.: 187) to create a SEQ ID NO.: 188. SEQ ID NO.: 188 was cloned into SEQ ID NOS.: 140, 142, 151 and 153 using SalI and XbaI.[1230]
• Oligonucleotides SEQ ID NOS.: 213, 214, 215 and 216 were used to amplify human GS1α from human cDNA to create SEQ ID NO.: 187. Using XhoI and XbaI a translational fusion was made between GS1α and human β2AR (SEQ ID NO.: 186) create SEQ ID NO.: 188. SEQ ID NO.: 188 was cloned into SEQ ID NOS.: 140, 142, 151and 153 using SalI and XbaI.[1231]
• Oligonucleotides SEQ ID NOS.: 213, 214, 215 and 217 were used to amplify human GS1α from human cDNA to create SEQ ID NO.: 192. Using XhoI and XbaI a translational fusion was made with ToxR residues 5-141 from[1232]Vibrio cholerae(SEQ ID NO.: 191) to create SEQ ID NO.: 197. To be used to create a transcriptional fusion with β2AR-ToxR chimeras as shown in SEQ ID NO.: 205 and future GPCR-ToxR chimeras.
• Oligonucleotides SEQ ID NOS.: 218, 219, 220 and 221 were used to amplify human Gα12/13 from human cDNA to create SEQ ID NO.: 196. Using XhoI and XbaI a translational fusion was made with ToxR residues 5-141 from[1233]Vibrio cholerae(SEQ ID NO.: 191) to create SEQ ID NO.: 201. To be used to create future transcriptional fusions with GPCR-ToxR chimeras as shown in SEQ ID NO.: 205.
• Oligonucleotides SEQ ID NOS.: 222, 223, 224 and 225 were used to amplify human Gαq from human cDNA to create SEQ ID NO.: 194. Using XhoI and XbaI a translational fusion was made with ToxR residues 5-141 from[1234]Vibrio cholerae(SEQ ID NO.: 191) to create SEQ ID NO.: 199. To be used to create future transcriptional fusions with GPCR-ToxR chimeras as shown in SEQ ID NO.: 205.
• Oligonucleotides SEQ ID NOS.: 226, 227, 228 and 229 were used to amplify human Giα from human cDNA to create SEQ ID NO.: 195. Using XhoI and XbaI a translational fusion was made with ToxR residues 5-141 from[1235]Vibrio cholerae(SEQ ID NO.: 191) to create SEQ ID NO.: 200. To be used to create future transcriptional fusions with GPCR-ToxR chimeras as shown in SEQ ID NO.: 205.
• Oligonucleotides SEQ ID NOS.: 230, 231, 232 and 233 were used to amplify human GS2α from human cDNA to create SEQ ID NO.: 193. Using XhoI and XbaI a translational fusion was made with ToxR residues 5-141 from[1236]Vibrio cholerae(SEQ ID NO.: 191) to create SEQ ID NO.: 198. To be used to create future transcriptional fusions with GPCR-ToxR chimeras as shown in SEQ ID NO.: 205.
• Oligonucleotides SEQ ID NOS.: 209, 210, 211 and 234 were used to amplify human β2AR from human cDNA to create SEQ ID NO.: 189. Using SalI and Xhol a transcriptional fusion was made between β2AR and human GS1α (SEQ ID NO.: 187) to create a SEQ ID NO.: 190. SEQ ID NO.: 190 was cloned into SEQ ID NOS.: 140, 142, 151 and 153 using SalI and XbaI.[1237]
• Oligonucleotides SEQ ID NOS.: 236, 237, 238 and 239 were used to amplify bases coinciding with ToxR residues 5-141 from[1238]Vibrio Choleraeto create SEQ ID NO.: 202. Using PstI and XhoI a translational fusion was made between ToxR and human β32AR (SEQ ID NO.: 203) to create SEQ ID NO.: 204.
• Oligonucleotides SEQ ID NOS.: 209, 210, 211 and 235 were used to amplify human β2AR from human cDNA to create SEQ ID NO.: 203. Using SalI and PstI a translational fusion was made between β2AR and ToxR (SEQ ID NO.: 202) to create SEQ ID NO.: 204.[1239]
• Using oligonucleotides SEQ ID NOS.: 197 and 204 transcriptional fusions were created between the β2AR-ToxR translational fusion (SEQ ID NO.: 204) and the GS 1α-ToxR translational fusion (SEQ ID NO.: 197) to create SEQ ID NO.: 205.[1240]
• Oligonucleotides SEQ ID NOS.: 240, 241, 242 and 243 were used to amplify the ctx promoter region (Pctx) from[1241]Vibrio choleraeto create SEQ ID NO.: 206. Combining this PCR product in combination with the SEQ ID NO.: 207 PCR product and amplifying in the presence of SEQ ID NOS.: 242, 247, SEQ ID NO.: 208 was created. Using XbaI, the SEQ ID NO.: 208 reporter construct was subsequently cloned into pACYC184 for co-transformation with the GPCR-G-protein fusions constructs above.
• Oligonucleotides SEQ ID NOS.: 244, 245, 246 and 247 were used to amplify the lacZ from[1242]E. colito create SEQ ID NO.: 207. Combining this PCR product in combination with the SEQ ID NO.: 206 PCR product and amplifying in the presence of SEQ ID NOS.: 242 and 247, SEQ ID NO.: 208 was created. Using XbaI, the 208 reporter construct was subsequently cloned into pACYC184 for co-transformation with the GPCR-G-protein fusions constructs above.
EXAMPLE 23Modular Membrane-Targeting and Solubilization Expression Constructs
• To produce membrane proteins efficiently in minicells it may be necessary to create chimeric fusions with the membrane protein of interest. In this Example various regions of the MalE protein have been cloned into a modular expression system designed to create chimeric fusions with direct difficult to target membrane proteins to produce leader domains that will direct the proteins to the cytoplasmic membrane ( Miller, K., W., et al. 1998. Production of active chimeric pediocin AcH in[1243]Escherichia coliin the absence of processing and secretion genes from thePediococcus papoperon. Appl. Environ. Microbiol. 64:14-20). Similarly, a modified version of the TrxA protein has also been cloned into this modular expression system to create chimeric fusions with proteins that are difficult to maintain in a soluble conformation (LaVallie, E. R., et al. 1993. A thioredoxin gene fusion expression system that circumvents inclusion body formation in theE. colicytoplasm. Biotechnology (N.Y.) 11:187-193). Table 31 describes each of these modular constructs.

  TABLE 31
  MODULAR MEMBRANE-TARGETING
  AND SOLUBILIZATION EXPRESSION CONSTRUCTS

  Proteina	Constructa	SEQ ID NO
  MalE (1-28)	NsiI-MalE (1-28)-Factor Xa-PstI, SalI, XbaI-FLAG, NheI	248
  MalE (1-370, del 354-364)	NsiI-MalE (1-370, del 354-364)-Factor Xa-PstI, SalI, XbaI-FLAG,	249
  	NheI
  TrxA (2-109, del 103-107)	PstI, SalI, XbaI-TrxA (2-109, del 103-107)-FLAG-NheI	250
  MalE (1-28)-TrxA (2-109,	NsiI-MalE (1-28)-Factor Xa-PstI, SalI, XbaI-TrxA (2-109 del 103-107)-	251
  del 103-107)	FLAG, NheI
  MalE (1-370, del 354-	NsiI-MalE (1-370, del 354-364)-Factor Xa-PstI, SalI, XbaI-TrxA (2-109	252
  364)-TrxA (2-109, del	del 103-107)-FLAG, NheI
  103-107)

• [1244]

  TABLE 32
  OLIGONUCLEOTIDE PRIMER SEQUENCES FOR TABLE 31.

  SEQ ID
  NO.:	Primer name	5′ to 3′ sequence

  253	MalE-1-NsiI	CGCGGATGCATATGAAAATAAAAACAGGTGCACGCATCCTCGCATT
  		ATCCGCATTAACGACGATGATGTTTTCCGCCTCGGCTCTCGCC
  254	MaE-2-middle	CGTCGACCGAGGCCTGCAGGCGGGCTTCGATGAGGCGAG
  		AGCCGAGGCGGAAAACATCATCGTCG
  255	MalE-3s-NheI	CGAAGCCCGCCTGCAGGCCTCGGTCGACGCCGAATCTAGAGATTAT
  		AAAGATGACGATGACAAATAATAAGCTAGCGGCGC
  256	MalE-4-NheI	GCGCCGCTAGCTTATTATTTGTCATCG
  257	MalE-1a	GGTGCACGCATCCTCGCATTATCCGC
  258	MalE-2a	GGCGTTTTCCATGGTGGCGGCAATACGTGG
  259	MalE-1-NsiI	CGCGGATGCATATGAAAATAAAAACAGGTGCACGCATCCTCGCATTATCCGC
  260	MalE-2-NheI	CCGAGGCCTGCAGGCGGGCTTCGATACGCACGGCATACCAG
  		AAAGCGGACTGGGCGTTTTCCATGGTGGCGGCAATACGTGG
  261	MalE-3L-NheI	GCGCCGCTAGCTTATTATTTGTCATCGTCATCTTTATAATCTC
  		TAGATTCGGCGTCGACCGAGGCCTGCAGGCGGGCTTCGATACGC
  262	TrxA-1a	CCTGACTGACGACAGTTTGACACGG
  263	TrxA-2a	CCTTTAGACAGTGCACCCACTTTGGTTGCCGC
  264	TrxA-1a-PstI	CGCGGCTGCAGGCCTCGGTCGACGCCGAATCTAGAAGCGAT
  		AAAATTATTCACCTGACTGACGACAGTTTTGACACGG
  265	TrxA-2-NheI	GCGCCGCTAGCTTATTATTTGTCATCGTCATCTTTATAATCCG
  		CCAGGTTCTCTTTCAACTGACCTTTAGACAGTGCACCCACTTT
  		GGTTGCCGC

• Oligonucleotides SEQ ID NOS.: 253, 254, 255 and 256 overlap with each other to form a scaffold template to PCR amplify malE (1-28) to create a SEQ ID NO.: 248. Following PCR amplification, SEQ ID NO.: 248 was digested with NsiI and NheI and cloned into SEQ ID NOS.: 152, 154, 139 and 141 digested with PstI and XbaI. The resultant products create SEQ ID NOS.: 266, 267, 268 and 269, respectively, that lose both the 5-prime PstI and 3-prime XbaI restriction site and retain the PstI, SalI, and XbaI restriction sites between MalE (1-28) and the FLAG sequence. Insertion of a protein in alignment with these sites results in a chimeric protein containing amino-terminal MalE (1-28 and carboxy-terminal FLAG.[1245]
• Oligonucleotides SEQ ID NOS.: 257, 258, 259 and 260 were used to amplify malE (1-370 with a deletion removing residues 354-364) to create SEQ ID NO.: 249. Following PCR amplification, SEQ ID NO.: 249 was digested with NsiI and NheI and cloned into SEQ ID NOS.: 152, 154, 139 and 141 digested with PstI and XbaI. The resultant products create SEQ ID NOS.: 270, 271, 272 and 273, respectively, that lose both the 5-prime PstI and 3-prime XbaI restriction site and retain the PstI, Sall, and XbaI restriction sites between MalE (1-370, del 354-364) and the FLAG sequence. Insertion of a protein in alignment with these sites results in a chimeric protein containing amino-terminal MalE (1-370, del 354-364) and carboxy-terminal FLAG.[1246]
• Oligonucleotides SEQ ID NOS.: 262, 263, 264 and 265 were used to amplify trxA (2-109 with a deletion removing residues 103-107) to create SEQ ID NO.: 250. Following PCR amplification, SEQ ID NO.: 250 was digested with PstI and NheI and cloned into SEQ ID NOS.: 152, 154, 139 and 141 digested with PstI and XbaI. to create SEQ ID NOS.: 274, 275, 276 and 277, respectively. Using these restriction digestion combinations results in loss of the XbaI SEQ ID NO.: 249 insertion site.[1247]
• The resultant products create SEQ ID NOS.: 274, 275, 276 and 277, respectively, that lose the 3-prime XbaI restriction site and retain the PstI, SalI, and XbaI restriction sites on the 3-prime end of the TrxA (1-109, del 103-107) sequence. Insertion of a protein in alignment with these sites results in a chimeric protein containing Carboxy-terminal TrxA (1-109, del 103-107)-FLAG.[1248]
• SEQ ID NO.: 248 was digested with NsiI and XbaI and cloned into SEQ ID NOS.: 274, 275, 276 and 277 that were digested with PstI and XbaI. The resultant products create SEQ ID NOS.: 278, 279, 280 and 281, respectively, that lose the 5 prime PstI restriction site and retain the PstI, SalI, and XbaI restriction sites between MalE (1-28) and TrxA (1-109, del 103-107). Insertion of a protein in alignment with these sites results in a chimeric protein containing amino-terminal MalE (1-28) and carboxy-terminal TrxA (1-109, del 103-107)-FLAG.[1249]
• SEQ ID NO.: 249 was digested with NsiI and XbaI and cloned into SEQ ID NOS.: 274, 275, 276 and 277 that were digested with PstI and XbaI. The resultant products create SEQ ID NOS.: 282, 283, 284 and 285, respectively, that lose the 5 prime PstI restriction site and retain the PstI, SalI, and XbaI restriction sites between MalE (1-370, del 354-364) and TrxA (1-109, del 103-107). Insertion of a protein in alignment with these sites results in a chimeric protein containing amino-terminal MalE (1-370, del 354-364) and carboxy-terminal TrxA (1-109, del 103-107)-FLAG.[1250]
EXAMPLE 24Poroplast™ Formation
• Minicells are used to prepare Poroplasts in order to increase the accessibility of a membrane protein component and/or domain to the outside environment. Membrane proteins in the inner membrane are accessible for ligand binding and/or other interactions in poroplasts, due to the absence of an outer membrane. The removal of the outer membrane from[1251]E. coliwhole cells and minicells to produce poroplasts was carried out using modifications of previously described protoplast and analysis protocols (Birdsell et al., Production and Ultrastructure of Lysozyme and Ethylenediaminetetraacetate-Lysozyme Spheroplasts ofEscherichia coli,J. Bacteriol. 93:427-437, 1967; Weiss et al., Protoplast Formation inEscherichia Coli,J. Bacteriol. 128:668-670, 1976; Matsuyama, S-I., et al. SecD is involved in the release of translocated secretory proteins from the cytoplasmic membrane ofEscherichia coli.12:265-270, 1993).
• In brief, cells were grown to late-log phase and pelleted at room temperature. Minicells were also isolated from cultures in late-log phase. The pellet was washed twice with 50 mM Tris, pH 8.0. Following the second wash, 1×10[1252]⁹cells were resuspended in 1 ml 50 mM Tris (pH 8.0) that contained 8% sucrose and 2 mM EDTA. Cell/EDTA/sucrose mixtures were incubated at 37° C. for 10 min, centrifuged, decanted, and poroplasted cells were resuspended in 50 mM Tris, pH 8.0 with 8% sucrose. Incubation with anti-LPS-coated magnetic beads, as described in Example 14, is used to enrich for poroplasts that lack LPS. Following incubation with the resuspended protoplasted cells, the anti-LPS magnetic beads were removed from suspension with a magnet.
• To examine the range of molecular sizes that can pass through the cell wall, an IgG molecule was tested for its ability to pass the intact cell wall. Binding of an antibody to the ToxR-PhoA chimera expressed on the inner membrane minicell poroplasts was measured. Briefly, minicell poroplasts with and without inner membrane-bound ToxR-PhoA were incubated at 37° C. with anti-PhoA antibody in reaction buffer (50 mM Tris, pH 8.0, 8% sucrose, 1% BSA, and 0.01% Tween-20). Following incubation, poroplasts were centrifuged, washed 3 times with reaction buffer, and resuspended in 50 mM Tris, pH 8.0 with 8% sucrose. Following resuspension, bound proteins from 5×10[1253]⁷minicells or minicell poroplasts were separated using denaturing SDS-PAGE, transferred to nitrocellulose, and developed using with both anti-PhoA antibody and secondary antibody against both heavy and light chains of anti-PhoA IgG (Table 33).

  TABLE 33
  ANTI-PHOA ACCESSIBILITY TO POROPLAST
  INNER MEMBRANE-BOUND TOXR-PHOA

  EDTA (mM)	0	2	0	2
  Lysozyme (mg/ml)	0	0	5	5

  	Poroplasts (ng antibody	Protoplasts (ng antibody
  	bound)	bound)

  Minicells ToxR-	NDa	0.6	NDa	12.8
  PhoA
  Minicells only	NDa	NDa	NDa	NDa

• These results demonstrate that the cell wall present on poroplasts is penetrable by an IgG molecule and that an IgG molecule is capable of passing the intact cell wall and binding to an inner membrane protein. From this data it appears that poroplast operate at ˜10% the efficiency of protoplasts by allowing 0.6 ng of IgG to bind inner membrane-bound ToxR-PhoA compared to 12.8 ng. However, given the large size of IgG (˜150,000 Daltons) it is expected that molecules having a smaller molecular weight will efficiently access inner membrane proteins in poroplasts.[1254]
EXAMPLE 25Production of Neurotensin Receptor (NTR)
• To demonstrate expression of NTR in isolated minicells, MalE(L)-NTR (SEQ ID NO.: 166 was cloned into pMPX-67 (SEQ ID NO.: 151). Following minicell isolation, 1.5×10[1255]⁹minicells were induced with 1 mM Rhamnose for 2 hour at 37° C. Following induction, the protein produced was visualized via Western analysis using an anti-MalE antibody following separation on an SDS-PAGE. The results are shown in FIG. 2.
• These data demonstrates that MalE(L)-NTR is induced 87-fold by addition of 1 mM rhamnose to the minicell induction mixture. Cross-reactive proteins are host MalE and non-specific binding by Goat-anti-mouse HRP secondary antibody.[1256]
• The contents of the articles, patents, and patent applications, and all other documents and electronically available information mentioned or cited herein, are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. Applicants reserve the right to physically incorporate into this application any and all materials and information from any such articles, patents, patent applications, or other documents.[1257]
• The inventions illustratively described herein may suitably be practiced in the absence of any element or elements, limitation or limitations, not specifically disclosed herein. Thus, for example, the terms “comprising”, “including,”containing”, etc. shall be read expansively and without limitation. Additionally, the terms and expressions employed herein have been used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the inventions embodied therein herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention.[1258]
• The invention has been described broadly and generically herein. Each of the narrower species and subgeneric groupings falling within the generic disclosure also form part of the invention. This includes the generic description of the invention with a proviso or negative limitation removing any subject matter from the genus, regardless of whether or not the excised material is specifically recited herein.[1259]
• Other embodiments are within the following claims. In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognize that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.[1260]
• 125811260DNAE. coli 1 ccatacccgt ttttttgggc tagcaggagg aattcaccct gcagatgttt gaaccaatgg 60 aacttaccaa tgacgcggtg attaaagtca tcggcgtcgg cggcggcggc ggtaatgctg 120 ttgaacacat ggtgcgcgag cgcattgaag gtgttgaatt cttcgcggta aataccgatg 180 cacaagcgct gcgtaaaaca gcggttggac agacgattca aatcggtagc ggtatcacca 240 aaggactggg cgctggcgct aatccagaag ttggccgcaa tgcggctgat gaggatcgcg 300 atgcattgcg tgcggcgctg gaaggtgcag acatggtctt tattgctgcg ggtatgggtg 360 gtggtaccgg tacaggtgca gcaccagtcg tcgctgaagt ggcaaaagat ttgggtatcc 420 tgaccgttgc tgtcgtcact aagcctttca actttgaagg caagaagcgt atggcattcg 480 cggagcaggg gatcactgaa ctgtccaagc atgtggactc tctgatcact atcccgaacg 540 acaaactgct gaaagttctg ggccgcggta tctccctgct ggatgcgttt ggcgcagcga 600 acgatgtact gaaaggcgct gtgcaaggta tcgctgaact gattactcgt ccgggtttga 660 tgaacgtgga ctttgcagac gtacgcaccg taatgtctga gatgggctac gcaatgatgg 720 gttctggcgt ggcgagcggt gaagaccgtg cggaagaagc tgctgaaatg gctatctctt 780 ctccgctgct ggaagatatc gacctgtctg gcgcgcgcgg cgtgctggtt aacatcacgg 840 cgggcttcga cctgcgtctg gatgagttcg aaacggtagg taacaccatc cgtgcatttg 900 cttccgacaa cgcgactgtg gttatcggta cttctcttga cccggatatg aatgacgagc 960 tgcgcgtaac cgttgttgcg acaggtatcg gcatggacaa acgtcctgaa atcactctgg 1020 tgaccaataa gcaggttcag cagccagtga tggatcgcta ccagcagcat gggatggctc 1080 cgctgaccca ggagcagaag ccggttgcta aagtcgtgaa tgacaatgcg ccgcaaactg 1140 cgaaagagcc ggattatctg gatatcccag cattcctgcg taagcaagct gattaataat 1200 ctagaggatc cccgggtacc gagctcgaat tcgtaatcat ggtcatagct gtttcctgtg 126021260DNAE. coli 2 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gtttgaacca atggaactta ccaatgacgc ggtgattaaa gtcatcggcg tcggcggcgg 120 cggcggtaat gctgttgaac acatggtgcg cgagcgcatt gaaggtgttg aattcttcgc 180 ggtaaatacc gatgcacaag cgctgcgtaa aacagcggtt ggacagacga ttcaaatcgg 240 tagcggtatc accaaaggac tgggcgctgg cgctaatcca gaagttggcc gcaatgcggc 300 tgatgaggat cgcgatgcat tgcgtgcggc gctggaaggt gcagacatgg tctttattgc 360 tgcgggtatg ggtggtggta ccggtacagg tgcagcacca gtcgtcgctg aagtggcaaa 420 agatttgggt atcctgaccg ttgctgtcgt cactaagcct ttcaactttg aaggcaagaa 480 gcgtatggca ttcgcggagc aggggatcac tgaactgtcc aagcatgtgg actctctgat 540 cactatcccg aacgacaaac tgctgaaagt tctgggccgc ggtatctccc tgctggatgc 600 gtttggcgca gcgaacgatg tactgaaagg cgctgtgcaa ggtatcgctg aactgattac 660 tcgtccgggt ttgatgaacg tggactttgc agacgtacgc accgtaatgt ctgagatggg 720 ctacgcaatg atgggttctg gcgtggcgag cggtgaagac cgtgcggaag aagctgctga 780 aatggctatc tcttctccgc tgctggaaga tatcgacctg tctggcgcgc gcggcgtgct 840 ggttaacatc acggcgggct tcgacctgcg tctggatgag ttcgaaacgg taggtaacac 900 catccgtgca tttgcttccg acaacgcgac tgtggttatc ggtacttctc ttgacccgga 960 tatgaatgac gagctgcgcg taaccgttgt tgcgacaggt atcggcatgg acaaacgtcc 1020 tgaaatcact ctggtgacca ataagcaggt tcagcagcca gtgatggatc gctaccagca 1080 gcatgggatg gctccgctga cccaggagca gaagccggtt gctaaagtcg tgaatgacaa 1140 tgcgccgcaa actgcgaaag agccggatta tctggatatc ccagcattcc tgcgtaagca 1200 agctgattaa taatctagag gatccccggg taccgagctc gaattcgtaa tcatggtcat 126032544DNAArtificial SequenceGene encoding a fusion protein 3 aagcctgcat tgcggcgctt cagtctccgc tgcatactgt cccgttacca attatgacaa 60 cttgacggct acatcattca ctttttcttc acaaccggca cggaactcgc tcgggctggc 120 cccggtgcat tttttaaata cccgcgagaa atagagttga tcgtcaaaac caacattgcg 180 accgacggtg gcgataggca tccgggtggt gctcaaaagc agcttcgcct ggctgatacg 240 ttggtcctcg cgccagctta agacgctaat ccctaactgc tggcggaaaa gatgtgacag 300 acgcgacggc gacaagcaaa catgctgtgc gacgctggcg atatcaaaat tgctgtctgc 360 caggtgatcg ctgatgtact gacaagcctc gcgtacccga ttatccatcg gtggatggag 420 cgactcgtta atcgcttcca tgcgccgcag taacaattgc tcaagcagat ttatcgccag 480 cagctccgaa tagcgccctt ccccttgccc ggcgttaatg atttgcccaa acaggtcgct 540 gaaatgcggc tggtgcgctt catccgggcg aaagaacccc gtattggcaa atattgacgg 600 ccagttaagc cattcatgcc agtaggcgcg cggacgaaag taaacccact ggtgatacca 660 ttcgcgagcc tccggatgac gaccgtagtg atgaatctct cctggcggga acagcaaaat 720 atcacccggt cggcaaacaa attctcgtcc ctgatttttc accaccccct gaccgcgaat 780 ggtgagattg agaatataac ctttcattcc cagcggtcgg tcgataaaaa aatcgagata 840 accgttggcc tcaatcggcg ttaaacccgc caccagatgg gcattaaacg agtatcccgg 900 cagcagggga tcattttgcg cttcagccat acttttcata ctcccgccat tcagagaaga 960 aaccaattgt ccatattgca tcagacattg ccgtcactgc gtcttttact ggctcttctc 1020 gctaaccaaa ccggtaaccc cgcttattaa aagcattctg taacaaagcg ggaccaaagc 1080 catgacaaaa acgcgtaaca aaagtgtcta taatcacggc agaaaagtcc acattgatta 1140 tttgcacggc gtcacacttt gctatgccat agcattttta tccataagat tagcggatcc 1200 tacctgacgc tttttatcgc aactctctac tgtttctcca tacccgtttt tttgggctag 1260 caggaggaat tcaccctgca gatgtttgaa ccaatggaac ttaccaatga cgcggtgatt 1320 aaagtcatcg gcgtcggcgg cggcggcggt aatgctgttg aacacatggt gcgcgagcgc 1380 attgaaggtg ttgaattctt cgcggtaaat accgatgcac aagcgctgcg taaaacagcg 1440 gttggacaga cgattcaaat cggtagcggt atcaccaaag gactgggcgc tggcgctaat 1500 ccagaagttg gccgcaatgc ggctgatgag gatcgcgatg cattgcgtgc ggcgctggaa 1560 ggtgcagaca tggtctttat tgctgcgggt atgggtggtg gtaccggtac aggtgcagca 1620 ccagtcgtcg ctgaagtggc aaaagatttg ggtatcctga ccgttgctgt cgtcactaag 1680 cctttcaact ttgaaggcaa gaagcgtatg gcattcgcgg agcaggggat cactgaactg 1740 tccaagcatg tggactctct gatcactatc ccgaacgaca aactgctgaa agttctgggc 1800 cgcggtatct ccctgctgga tgcgtttggc gcagcgaacg atgtactgaa aggcgctgtg 1860 caaggtatcg ctgaactgat tactcgtccg ggtttgatga acgtggactt tgcagacgta 1920 cgcaccgtaa tgtctgagat gggctacgca atgatgggtt ctggcgtggc gagcggtgaa 1980 gaccgtgcgg aagaagctgc tgaaatggct atctcttctc cgctgctgga agatatcgac 2040 ctgtctggcg cgcgcggcgt gctggttaac atcacggcgg gcttcgacct gcgtctggat 2100 gagttcgaaa cggtaggtaa caccatccgt gcatttgctt ccgacaacgc gactgtggtt 2160 atcggtactt ctcttgaccc ggatatgaat gacgagctgc gcgtaaccgt tgttgcgaca 2220 ggtatcggca tggacaaacg tcctgaaatc actctggtga ccaataagca ggttcagcag 2280 ccagtgatgg atcgctacca gcagcatggg atggctccgc tgacccagga gcagaagccg 2340 gttgctaaag tcgtgaatga caatgcgccg caaactgcga aagagccgga ttatctggat 2400 atcccagcat tcctgcgtaa gcaagctgat taataatcta gaggcgttac caattatgac 2460 aacttgacgg gaagttccta tactttctag agaataggaa cttcccaaag ccagtatcaa 2520 ctcagacaaa ggcaaagcat cttg 254443350DNAArtificial SequenceGene encoding a fusion protein 4 aagcctgcat tgcggcgctt cagtctccgc tgcatactgt ccttaatctt tctgcgaatt 60 gagatgacgc cactggctgg gcgtcatccc ggtttcccgg gtaaacacca ccgaaaaata 120 gttactatct tcaaagccac attcggtcga aatatcactg attaacaggc ggctatgctg 180 gagaagatat tgcgcatgac acactctgac ctgtcgcaga tattgattga tggtcattcc 240 agtctgctgg cgaaattgct gacgcaaaac gcgctcactg cacgatgcct catcacaaaa 300 tttatccagc gcaaagggac ttttcaggct agccgccagc cgggtaatca gcttatccag 360 caacgtttcg ctggatgttg gcggcaacga atcactggtg taacgatggc gattcagcaa 420 catcaccaac tgcccgaaca gcaactcagc catttcgtta gcaaacggca catgctgact 480 actttcatgc tcaagctgac cgataacctg ccgcgcctgc gccatcccca tgctacctaa 540 gcgccagtgt ggttgccctg cgctggcgtt aaatcccgga atcgccccct gccagtcaag 600 attcagcttc agacgctccg ggcaataaat aatattctgc aaaaccagat cgttaacgga 660 agcgtaggag tgtttatcgt cagcatgaat gtaaaagaga tcgccacggg taatgcgata 720 agggcgatcg ttgagtacat gcaggccatt accgcgccag acaatcacca gctcacaaaa 780 atcatgtgta tgttcagcaa agacatcttg cggataacgg tcagccacag cgactgcctg 840 ctggtcgctg gcaaaaaaat catctttgag aagttttaac tgatgcgcca ccgtggctac 900 ctcggccaga gaacgaagtt gattattcgc aatatggcgt acaaatacgt tgagaagatt 960 cgcgttattg cagaaagcca tcccgtccct ggcgaatatc acgcggtgac cagttaaact 1020 ctcggcgaaa aagcgtcgaa aagtggttac tgtcgctgaa tccacagcga taggcgatgt 1080 cagtaacgct ggcctcgctg tggcgtagca gatgtcgggc tttcatcagt cgcaggcggt 1140 tcaggtatcg ctgaggcgtc agtcccgttt gctgcttaag ctgccgatgt agcgtacgca 1200 gtgaaagaga aaattgatcc gccacggcat cccaattcac ctcatcggca aaatggtcct 1260 ccagccaggc cagaagcaag ttgagacgtg atgcgctgtt ttccaggttc tcctgcaaac 1320 tgcttttacg cagcaagagc agtaattgca taaacaagat ctcgcgactg gcggtcgagg 1380 gtaaatcatt ttccccttcc tgctgttcca tctgtgcaac cagctgtcgc acctgctgca 1440 atacgctgtg gttaacgcgc cagtgagacg gatactgccc atccagctct tgtggcagca 1500 actgattcag cccggcgaga aactgaaatc gatccggcga gcgatacagc acattggtca 1560 gacacagatt atcggtatgt tcatacagat gccgatcatg atcgcgtacg aaacagaccg 1620 tgccaccggt gatggtatag ggctgcccat taaacacatg aatacccgtg ccatgttcga 1680 caatcacaat ttcatgaaaa tcatgatgat gttcaggaaa atccgcctgc gggagccggg 1740 gttctatcgc cacggacgcg ttaccagacg gaaaaaaatc cacactatgt aatacggtca 1800 tactggcctc ctgatgtcgt caacacggcg aaatagtaat cacgaggtca ggttcttacc 1860 ttaaattttc gacggaaaac cacgtaaaaa acgtcgattt ttcaagatac agcgtgaatt 1920 ttcaggaaat gcggtgagca tcacatcacc acaattcagc aaattgtgaa catcatcacg 1980 ttcatctttc cctggttgcc aatggcccat tttcctgtca gtaacgagaa ggtcgcgaat 2040 tcaggcgctt tttagactgg tcgtaatgaa attcagcagg atcacatatg tttgaaccaa 2100 tggaacttac caatgacgcg gtgattaaag tcatcggcgt cggcggcggc ggcggtaatg 2160 ctgttgaaca catggtgcgc gagcgcattg aaggtgttga attcttcgcg gtaaataccg 2220 atgcacaagc gctgcgtaaa acagcggttg gacagacgat tcaaatcggt agcggtatca 2280 ccaaaggact gggcgctggc gctaatccag aagttggccg caatgcggct gatgaggatc 2340 gcgatgcatt gcgtgcggcg ctggaaggtg cagacatggt ctttattgct gcgggtatgg 2400 gtggtggtac cggtacaggt gcagcaccag tcgtcgctga agtggcaaaa gatttgggta 2460 tcctgaccgt tgctgtcgtc actaagcctt tcaactttga aggcaagaag cgtatggcat 2520 tcgcggagca ggggatcact gaactgtcca agcatgtgga ctctctgatc actatcccga 2580 acgacaaact gctgaaagtt ctgggccgcg gtatctccct gctggatgcg tttggcgcag 2640 cgaacgatgt actgaaaggc gctgtgcaag gtatcgctga actgattact cgtccgggtt 2700 tgatgaacgt ggactttgca gacgtacgca ccgtaatgtc tgagatgggc tacgcaatga 2760 tgggttctgg cgtggcgagc ggtgaagacc gtgcggaaga agctgctgaa atggctatct 2820 cttctccgct gctggaagat atcgacctgt ctggcgcgcg cggcgtgctg gttaacatca 2880 cggcgggctt cgacctgcgt ctggatgagt tcgaaacggt aggtaacacc atccgtgcat 2940 ttgcttccga caacgcgact gtggttatcg gtacttctct tgacccggat atgaatgacg 3000 agctgcgcgt aaccgttgtt gcgacaggta tcggcatgga caaacgtcct gaaatcactc 3060 tggtgaccaa taagcaggtt cagcagccag tgatggatcg ctaccagcag catgggatgg 3120 ctccgctgac ccaggagcag aagccggttg ctaaagtcgt gaatgacaat gcgccgcaaa 3180 ctgcgaaaga gccggattat ctggatatcc cagcattcct gcgtaagcaa gctgattaat 3240 aatctagagg cgttaccaat tatgacaact tgacgggaag ttcctatact ttctagagaa 3300 taggaacttc ccaaagccag tatcaactca gacaaaggca aagcatcttg 335052280DNAArtificial SequenceGene encoding a fusion protein 5 aagcctgcat tgcggcgctt cagtctccgc tgcatactgt ccttaataaa gtgagtcgat 60 attgtctttg ttgaccagta ataccttatg gaaacggata attcgcttat ccatatctac 120 gtcggcctta cccagattct gcatttctaa tccaggcttg atctcttcac ccttcagcaa 180 cgtgctggcg acggctgcga gtgcgtaacc tgcagaggcc ggatcgtaag taatcccttc 240 ggtgatatca ccacttttaa tcagtgatgc cgcctgtgaa gggatcatca tgccatagac 300 tgcgacttta tttttcgccc gtttctcttt caccgcacgt cccgcgccaa tcggaccgtt 360 tgaaccaaag gagacaaccg ctttcaagtc aggataggtt ttcatcaggt ccagtgtagt 420 acgacgtgag acatccacac tctcggcaac cggcatgcgg cgggtaactt catgcatatc 480 cgggtaatgc tctttctggt atttcaccag caagtcagcc cataagttat gctgcggcac 540 ggtcaaacta cccacgtaaa tcacatagcc gcccttgcca cccatgcgtt tcgccatatg 600 ctcaacatat tcagcggcaa atttttcgtt atcaatgatt tcgatatccc agttagcact 660 tggctgaccg ggggattcgt tggtcagaac cacaattccg gcatctcgcg cttttttgaa 720 taccggttcc agcacgttgg catcgtttgg cacgatagta attgcattaa ccttacgggc 780 gattaaatcc tcaataattt taacttgttg cggagcatca gtacttgaag gccccacctg 840 tgaggcatta acaccaaagg ctttacccgc ctcaaccaca ccttcgccca tgcgattaaa 900 ccacggcata ccatcgactt tagaaatatt caccacgact ttttccgctg cctggagcgg 960 cgcagaaatt agcgcagcgc ctaataacag cgaagacacc atattgataa caaaacgttt 1020 attcatcata tggaacttac caatgacgcg gtgattaaag tcatcggcgt cggcggcggc 1080 ggcggtaatg ctgttgaaca catggtgcgc gagcgcattg aaggtgttga attcttcgcg 1140 gtaaataccg atgcacaagc gctgcgtaaa acagcggttg gacagacgat tcaaatcggt 1200 agcggtatca ccaaaggact gggcgctggc gctaatccag aagttggccg caatgcggct 1260 gatgaggatc gcgatgcatt gcgtgcggcg ctggaaggtg cagacatggt ctttattgct 1320 gcgggtatgg gtggtggtac cggtacaggt gcagcaccag tcgtcgctga agtggcaaaa 1380 gatttgggta tcctgaccgt tgctgtcgtc actaagcctt tcaactttga aggcaagaag 1440 cgtatggcat tcgcggagca ggggatcact gaactgtcca agcatgtgga ctctctgatc 1500 actatcccga acgacaaact gctgaaagtt ctgggccgcg gtatctccct gctggatgcg 1560 tttggcgcag cgaacgatgt actgaaaggc gctgtgcaag gtatcgctga actgattact 1620 cgtccgggtt tgatgaacgt ggactttgca gacgtacgca ccgtaatgtc tgagatgggc 1680 tacgcaatga tgggttctgg cgtggcgagc ggtgaagacc gtgcggaaga agctgctgaa 1740 atggctatct cttctccgct gctggaagat atcgacctgt ctggcgcgcg cggcgtgctg 1800 gttaacatca cggcgggctt cgacctgcgt ctggatgagt tcgaaacggt aggtaacacc 1860 atccgtgcat ttgcttccga caacgcgact gtggttatcg gtacttctct tgacccggat 1920 atgaatgacg agctgcgcgt aaccgttgtt gcgacaggta tcggcatgga caaacgtcct 1980 gaaatcactc tggtgaccaa taagcaggtt cagcagccag tgatggatcg ctaccagcag 2040 catgggatgg ctccgctgac ccaggagcag aagccggttg ctaaagtcgt gaatgacaat 2100 gcgccgcaaa ctgcgaaaga gccggattat ctggatatcc cagcattcct gcgtaagcaa 2160 gctgattaat aatctagagg cgttaccaat tatgacaact tgacgggaag ttcctattct 2220 ctagaaagta taggaacttc ccaaagccag tatcaactca gacaaaggca aagcatcttg 228064728DNAArtificial SequenceExpression vector 6 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttaattaa tctttctgcg 420 aattgagatg acgccactgg ctgggcgtca tcccggtttc ccgggtaaac accaccgaaa 480 aatagttact atcttcaaag ccacattcgg tcgaaatatc actgattaac aggcggctat 540 gctggagaag atattgcgca tgacacactc tgacctgtcg cagatattga ttgatggtca 600 ttccagtctg ctggcgaaat tgctgacgca aaacgcgctc actgcacgat gcctcatcac 660 aaaatttatc cagcgcaaag ggacttttca ggctagccgc cagccgggta atcagcttat 720 ccagcaacgt ttcgctggat gttggcggca acgaatcact ggtgtaacga tggcgattca 780 gcaacatcac caactgcccg aacagcaact cagccatttc gttagcaaac ggcacatgct 840 gactactttc atgctcaagc tgaccgataa cctgccgcgc ctgcgccatc cccatgctac 900 ctaagcgcca gtgtggttgc cctgcgctgg cgttaaatcc cggaatcgcc ccctgccagt 960 caagattcag cttcagacgc tccgggcaat aaataatatt ctgcaaaacc agatcgttaa 1020 cggaagcgta ggagtgttta tcgtcagcat gaatgtaaaa gagatcgcca cgggtaatgc 1080 gataagggcg atcgttgagt acatgcaggc cattaccgcg ccagacaatc accagctcac 1140 aaaaatcatg tgtatgttca gcaaagacat cttgcggata acggtcagcc acagcgactg 1200 cctgctggtc gctggcaaaa aaatcatctt tgagaagttt taactgatgc gccaccgtgg 1260 ctacctcggc cagagaacga agttgattat tcgcaatatg gcgtacaaat acgttgagaa 1320 gattcgcgtt attgcagaaa gccatcccgt ccctggcgaa tatcacgcgg tgaccagtta 1380 aactctcggc gaaaaagcgt cgaaaagtgg ttactgtcgc tgaatccaca gcgataggcg 1440 atgtcagtaa cgctggcctc gctgtggcgt agcagatgtc gggctttcat cagtcgcagg 1500 cggttcaggt atcgctgagg cgtcagtccc gtttgctgct taagctgccg atgtagcgta 1560 cgcagtgaaa gagaaaattg atccgccacg gcatcccaat tcacctcatc ggcaaaatgg 1620 tcctccagcc aggccagaag caagttgaga cgtgatgcgc tgttttccag gttctcctgc 1680 aaactgcttt tacgcagcaa gagcagtaat tgcataaaca agatctcgcg actggcggtc 1740 gagggtaaat cattttcccc ttcctgctgt tccatctgtg caaccagctg tcgcacctgc 1800 tgcaatacgc tgtggttaac gcgccagtga gacggatact gcccatccag ctcttgtggc 1860 agcaactgat tcagcccggc gagaaactga aatcgatccg gcgagcgata cagcacattg 1920 gtcagacaca gattatcggt atgttcatac agatgccgat catgatcgcg tacgaaacag 1980 accgtgccac cggtgatggt atagggctgc ccattaaaca catgaatacc cgtgccatgt 2040 tcgacaatca caatttcatg aaaatcatga tgatgttcag gaaaatccgc ctgcgggagc 2100 cggggttcta tcgccacgga cgcgttacca gacggaaaaa aatccacact atgtaatacg 2160 gtcatactgg cctcctgatg tcgtcaacac ggcgaaatag taatcacgag gtcaggttct 2220 taccttaaat tttcgacgga aaaccacgta aaaaacgtcg atttttcaag atacagcgtg 2280 aattttcagg aaatgcggtg agcatcacat caccacaatt cagcaaattg tgaacatcat 2340 cacgttcatc tttccctggt tgccaatggc ccattttcct gtcagtaacg agaaggtcgc 2400 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcaggt 2460 cgactctaga ggatccccgg gtaccgagct cgaattcgta atcatggtca tagctgtttc 2520 ctgtgtgaaa ttgttatccg ctcacaattc cacacaacat acgagccgga agcataaagt 2580 gtaaagcctg gggtgcctaa tgagtgagct aactcacatt aattgcgttg cgctcactgc 2640 ccgctttcca gtcgggaaac ctgtcgtgcc agctgcatta atgaatcggc caacgcgcgg 2700 ggagaggcgg tttgcgtatt gggcgctctt ccgcttcctc gctcactgac tcgctgcgct 2760 cggtcgttcg gctgcggcga gcggtatcag ctcactcaaa ggcggtaata cggttatcca 2820 cagaatcagg ggataacgca ggaaagaaca tgtgagcaaa aggccagcaa aaggccagga 2880 accgtaaaaa ggccgcgttg ctggcgtttt tccataggct ccgcccccct gacgagcatc 2940 acaaaaatcg acgctcaagt cagaggtggc gaaacccgac aggactataa agataccagg 3000 cgtttccccc tggaagctcc ctcgtgcgct ctcctgttcc gaccctgccg cttaccggat 3060 acctgtccgc ctttctccct tcgggaagcg tggcgctttc tcatagctca cgctgtaggt 3120 atctcagttc ggtgtaggtc gttcgctcca agctgggctg tgtgcacgaa ccccccgttc 3180 agcccgaccg ctgcgcctta tccggtaact atcgtcttga gtccaacccg gtaagacacg 3240 acttatcgcc actggcagca gccactggta acaggattag cagagcgagg tatgtaggcg 3300 gtgctacaga gttcttgaag tggtggccta actacggcta cactagaagg acagtatttg 3360 gtatctgcgc tctgctgaag ccagttacct tcggaaaaag agttggtagc tcttgatccg 3420 gcaaacaaac caccgctggt agcggtggtt tttttgtttg caagcagcag attacgcgca 3480 gaaaaaaagg atctcaagaa gatcctttga tcttttctac ggggtctgac gctcagtgga 3540 acgaaaactc acgttaaggg attttggtca tgagattatc aaaaaggatc ttcacctaga 3600 tccttttaaa ttaaaaatga agttttaaat caatctaaag tatatatgag taaacttggt 3660 ctgacagtta ccaatgctta atcagtgagg cacctatctc agcgatctgt ctatttcgtt 3720 catccatagt tgcctgactc cccgtcgtgt agataactac gatacgggag ggcttaccat 3780 ctggccccag tgctgcaatg ataccgcgag acccacgctc accggctcca gatttatcag 3840 caataaacca gccagccgga agggccgagc gcagaagtgg tcctgcaact ttatccgcct 3900 ccatccagtc tattaattgt tgccgggaag ctagagtaag tagttcgcca gttaatagtt 3960 tgcgcaacgt tgttgccatt gctacaggca tcgtggtgtc acgctcgtcg tttggtatgg 4020 cttcattcag ctccggttcc caacgatcaa ggcgagttac atgatccccc atgttgtgca 4080 aaaaagcggt tagctccttc ggtcctccga tcgttgtcag aagtaagttg gccgcagtgt 4140 tatcactcat ggttatggca gcactgcata attctcttac tgtcatgcca tccgtaagat 4200 gcttttctgt gactggtgag tactcaacca agtcattctg agaatagtgt atgcggcgac 4260 cgagttgctc ttgcccggcg tcaatacggg ataataccgc gccacatagc agaactttaa 4320 aagtgctcat cattggaaaa cgttcttcgg ggcgaaaact ctcaaggatc ttaccgctgt 4380 tgagatccag ttcgatgtaa cccactcgtg cacccaactg atcttcagca tcttttactt 4440 tcaccagcgt ttctgggtga gcaaaaacag gaaggcaaaa tgccgcaaaa aagggaataa 4500 gggcgacacg gaaatgttga atactcatac tcttcctttt tcaatattat tgaagcattt 4560 atcagggtta ttgtctcatg agcggataca tatttgaatg tatttagaaa aataaacaaa 4620 taggggttcc gcgcacattt ccccgaaaag tgccacctga cgtctaagaa accattatta 4680 tcatgacatt aacctataaa aataggcgta tcacgaggcc ctttcgtc 472871440DNAE. coli 7 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gcctgttctg gaaaaccggg ctgctcaggg cgatattact gcacccggcg gtgctcgccg 120 tttaacgggt gatcagactg ccgctctgcg tgattctctt agcgataaac ctgcaaaaaa 180 tattattttg ctgattggcg atgggatggg ggactcggaa attactgccg cacgtaatta 240 tgccgaaggt gcgggcggct tttttaaagg tatagatgcc ttaccgctta ccgggcaata 300 cactcactat gcgctgaata aaaaaaccgg caaaccggac tacgtcaccg actcggctgc 360 atcagcaacc gcctggtcaa ccggtgtcaa aacctataac ggcgcgctgg gcgtcgatat 420 tcacgaaaaa gatcacccaa cgattctgga aatggcaaaa gccgcaggtc tggcgaccgg 480 taacgtttct accgcagagt tgcaggatgc cacgcccgct gcgctggtgg cacatgtgac 540 ctcgcgcaaa tgctacggtc cgagcgcgac cagtgaaaaa tgtccgggta acgctctgga 600 aaaaggcgga aaaggatcga ttaccgaaca gctgcttaac gctcgtgccg acgttacgct 660 tggcggcggc gcaaaaacct ttgctgaaac ggcaaccgct ggtgaatggc agggaaaaac 720 gctgcgtgaa caggcacagg cgcgtggtta tcagttggtg agcgatgctg cctcactgaa 780 ttcggtgacg gaagcgaatc agcaaaaacc cctgcttggc ctgtttgctg acggcaatat 840 gccagtgcgc tggctaggac cgaaagcaac gtaccatggc aatatcgata agcccgcagt 900 cacctgtacg ccaaatccgc aacgtaatga cagtgtacca accctggcgc agatgaccga 960 caaagccatt gaattgttga gtaaaaatga gaaaggcttt ttcctgcaag ttgaaggtgc 1020 gtcaatcgat aaacaggatc atgctgcgaa tccttgtggg caaattggcg agacggtcga 1080 tctcgatgaa gccgtacaac gggcgctgga attcgctaaa aaggagggta acacgctggt 1140 catagtcacc gctgatcacg cccacgccag ccagattgtt gcgccggata ccaaagctcc 1200 gggcctcacc caggcgctaa ataccaaaga tggcgcagtg atggtgatga gttacgggaa 1260 ctccgaagag gattcacaag aacataccgg cagtcagttg cgtattgcgg cgtatggccc 1320 gcatgccgcc aatgttgttg gactgaccga ccagaccgat ctcttctaca ccatgaaagc 1380 cgctctgggg ctgaaataat aatctagagg atccccgggt accgagctcg aattcgtaat 144081560DNAE. coli 8 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gtcacggccg agacttatag tcgctttgtt tttatttttt aatgtatttg tacatggaga 120 aaataaagtg aaacaaagca ctattgcact ggcactctta ccgttactgt ttacccctgt 180 gacaaaagcc cggacaccag aaatgcctgt tctggaaaac cgggctgctc agggcgatat 240 tactgcaccc ggcggtgctc gccgtttaac gggtgatcag actgccgctc tgcgtgattc 300 tcttagcgat aaacctgcaa aaaatattat tttgctgatt ggcgatggga tgggggactc 360 ggaaattact gccgcacgta attatgccga aggtgcgggc ggctttttta aaggtataga 420 tgccttaccg cttaccgggc aatacactca ctatgcgctg aataaaaaaa ccggcaaacc 480 ggactacgtc accgactcgg ctgcatcagc aaccgcctgg tcaaccggtg tcaaaaccta 540 taacggcgcg ctgggcgtcg atattcacga aaaagatcac ccaacgattc tggaaatggc 600 aaaagccgca ggtctggcga ccggtaacgt ttctaccgca gagttgcagg atgccacgcc 660 cgctgcgctg gtggcacatg tgacctcgcg caaatgctac ggtccgagcg cgaccagtga 720 aaaatgtccg ggtaacgctc tggaaaaagg cggaaaagga tcgattaccg aacagctgct 780 taacgctcgt gccgacgtta cgcttggcgg cggcgcaaaa acctttgctg aaacggcaac 840 cgctggtgaa tggcagggaa aaacgctgcg tgaacaggca caggcgcgtg gttatcagtt 900 ggtgagcgat gctgcctcac tgaattcggt gacggaagcg aatcagcaaa aacccctgct 960 tggcctgttt gctgacggca atatgccagt gcgctggcta ggaccgaaag caacgtacca 1020 tggcaatatc gataagcccg cagtcacctg tacgccaaat ccgcaacgta atgacagtgt 1080 accaaccctg gcgcagatga ccgacaaagc cattgaattg ttgagtaaaa atgagaaagg 1140 ctttttcctg caagttgaag gtgcgtcaat cgataaacag gatcatgctg cgaatccttg 1200 tgggcaaatt ggcgagacgg tcgatctcga tgaagccgta caacgggcgc tggaattcgc 1260 taaaaaggag ggtaacacgc tggtcatagt caccgctgat cacgcccacg ccagccagat 1320 tgttgcgccg gataccaaag ctccgggcct cacccaggcg ctaaatacca aagatggcgc 1380 agtgatggtg atgagttacg ggaactccga agaggattca caagaacata ccggcagtca 1440 gttgcgtatt gcggcgtatg gcccgcatgc cgccaatgtt gttggactga ccgaccagac 1500 cgatctcttc tacaccatga aagccgctct ggggctgaaa taatctagag gatccccggg 156091500DNAArtificial SequenceGene encoding a fusion protein 9 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gaacttgggg aatcgactgt ttattctgat agcggtctta cttcccctcg cagtattact 120 gctcatgcct gttctggaaa accgggctgc tcagggcgat attactgcac ccggcggtgc 180 tcgccgttta acgggtgatc agactgccgc tctgcgtgat tctcttagcg ataaacctgc 240 aaaaaatatt attttgctga ttggcgatgg gatgggggac tcggaaatta ctgccgcacg 300 taattatgcc gaaggtgcgg gcggcttttt taaaggtata gatgccttac cgcttaccgg 360 gcaatacact cactatgcgc tgaataaaaa aaccggcaaa ccggactacg tcaccgactc 420 ggctgcatca gcaaccgcct ggtcaaccgg tgtcaaaacc tataacggcg cgctgggcgt 480 cgatattcac gaaaaagatc acccaacgat tctggaaatg gcaaaagccg caggtctggc 540 gaccggtaac gtttctaccg cagagttgca ggatgccacg cccgctgcgc tggtggcaca 600 tgtgacctcg cgcaaatgct acggtccgag cgcgaccagt gaaaaatgtc cgggtaacgc 660 tctggaaaaa ggcggaaaag gatcgattac cgaacagctg cttaacgctc gtgccgacgt 720 tacgcttggc ggcggcgcaa aaacctttgc tgaaacggca accgctggtg aatggcaggg 780 aaaaacgctg cgtgaacagg cacaggcgcg tggttatcag ttggtgagcg atgctgcctc 840 actgaattcg gtgacggaag cgaatcagca aaaacccctg cttggcctgt ttgctgacgg 900 caatatgcca gtgcgctggc taggaccgaa agcaacgtac catggcaata tcgataagcc 960 cgcagtcacc tgtacgccaa atccgcaacg taatgacagt gtaccaaccc tggcgcagat 1020 gaccgacaaa gccattgaat tgttgagtaa aaatgagaaa ggctttttcc tgcaagttga 1080 aggtgcgtca atcgataaac aggatcatgc tgcgaatcct tgtgggcaaa ttggcgagac 1140 ggtcgatctc gatgaagccg tacaacgggc gctggaattc gctaaaaagg agggtaacac 1200 gctggtcata gtcaccgctg atcacgccca cgccagccag attgttgcgc cggataccaa 1260 agctccgggc ctcacccagg cgctaaatac caaagatggc gcagtgatgg tgatgagtta 1320 cgggaactcc gaagaggatt cacaagaaca taccggcagt cagttgcgta ttgcggcgta 1380 tggcccgcat gccgccaatg ttgttggact gaccgaccag accgatctct tctacaccat 1440 gaaagccgct ctggggctga aataataatc tagaggatcc ccgggtaccg agctcgaatt 1500103908DNAArtificial SequenceExpression vector 10 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tgctcgcctg ctgcgagctg ggtaagcgga caaattctca ccgtctccgg tggtggggta 420 caggagctca attaatacac taacggaccg gtaaacaacc gtgcgtgttg tttaccggga 480 taaactcatc aacgtctctg ctaaataact ggcagccaaa tcacggctat tggttaacca 540 atttcagagt gaaaagtata cgaatagagt gtgccttcgc actattcaac agcaatgata 600 ggcgctcacc tgacaacgcg gtaaactagt tattcacgct aactataatg gtttaatgat 660 ggataacatg cagactgaag cacaaccgac acggacccgg atcctcaatg ctgccagaga 720 gattttttca gaaaatggat ttcacagtgc ctcgatgaaa gccatctgta aatcttgcgc 780 cattagtccc gggacgctct atcaccattt catctccaaa gaagccttga ttcaggcgat 840 tatcttacag gaccaggaga gggcgctggc ccgtttccgg gaaccgattg aagggattca 900 tttcgttgac tatatggtcg agtccattgt ctctctcacc catgaagcct ttggacaacg 960 ggcgctggtg gttgaaatta tggcggaagg gatgcgtaac ccacaggtcg ccgccatgct 1020 taaaaataag catatgacga tcacggaatt tgttgcccag cggatgcgtg atgcccagca 1080 aaaaggcgag ataagcccag acatcaacac ggcaatgact tcacgtttac tgctggatct 1140 gacctacggt gtactggccg atatcgaagc ggaagacctg gcgcgtgaag cgtcgtttgc 1200 tcagggatta cgcgcgatga ttggcggtat cttaaccgca tcctgattct ctctcttttt 1260 cggcgggctg gtgataactg tgcccgcgtt tcatatcgta atttctctgt gcaaaaatta 1320 tccttcccgg cttcggagaa ttccccccaa aatattcact gtagccatat gtcatgagag 1380 tttatcgttc ccaatacgct cgaacgaacg ttcggttgct tattttatgg cttctgtcaa 1440 cgctgtttta aagattaatg cgatctatat cacgctgtgg gtattgcagt ttttggtttt 1500 ttgatcgcgg tgtcagttct ttttatttcc atttctcttc catgggtttc tcacagataa 1560 ctgtgtgcaa cacagaattg gttaactaat cagattaaag gttgaccagt attattatct 1620 taatgaggag tcctgcaggt cgactctaga ggatccccgg gtaccgagct cgaattcgta 1680 atcatggtca tagctgtttc ctgtgtgaaa ttgttatccg ctcacaattc cacacaacat 1740 acgagccgga agcataaagt gtaaagcctg gggtgcctaa tgagtgagct aactcacatt 1800 aattgcgttg cgctcactgc ccgctttcca gtcgggaaac ctgtcgtgcc agctgcatta 1860 atgaatcggc caacgcgcgg ggagaggcgg tttgcgtatt gggcgctctt ccgcttcctc 1920 gctcactgac tcgctgcgct cggtcgttcg gctgcggcga gcggtatcag ctcactcaaa 1980 ggcggtaata cggttatcca cagaatcagg ggataacgca ggaaagaaca tgtgagcaaa 2040 aggccagcaa aaggccagga accgtaaaaa ggccgcgttg ctggcgtttt tccataggct 2100 ccgcccccct gacgagcatc acaaaaatcg acgctcaagt cagaggtggc gaaacccgac 2160 aggactataa agataccagg cgtttccccc tggaagctcc ctcgtgcgct ctcctgttcc 2220 gaccctgccg cttaccggat acctgtccgc ctttctccct tcgggaagcg tggcgctttc 2280 tcatagctca cgctgtaggt atctcagttc ggtgtaggtc gttcgctcca agctgggctg 2340 tgtgcacgaa ccccccgttc agcccgaccg ctgcgcctta tccggtaact atcgtcttga 2400 gtccaacccg gtaagacacg acttatcgcc actggcagca gccactggta acaggattag 2460 cagagcgagg tatgtaggcg gtgctacaga gttcttgaag tggtggccta actacggcta 2520 cactagaagg acagtatttg gtatctgcgc tctgctgaag ccagttacct tcggaaaaag 2580 agttggtagc tcttgatccg gcaaacaaac caccgctggt agcggtggtt tttttgtttg 2640 caagcagcag attacgcgca gaaaaaaagg atctcaagaa gatcctttga tcttttctac 2700 ggggtctgac gctcagtgga acgaaaactc acgttaaggg attttggtca tgagattatc 2760 aaaaaggatc ttcacctaga tccttttaaa ttaaaaatga agttttaaat caatctaaag 2820 tatatatgag taaacttggt ctgacagtta ccaatgctta atcagtgagg cacctatctc 2880 agcgatctgt ctatttcgtt catccatagt tgcctgactc cccgtcgtgt agataactac 2940 gatacgggag ggcttaccat ctggccccag tgctgcaatg ataccgcgag acccacgctc 3000 accggctcca gatttatcag caataaacca gccagccgga agggccgagc gcagaagtgg 3060 tcctgcaact ttatccgcct ccatccagtc tattaattgt tgccgggaag ctagagtaag 3120 tagttcgcca gttaatagtt tgcgcaacgt tgttgccatt gctacaggca tcgtggtgtc 3180 acgctcgtcg tttggtatgg cttcattcag ctccggttcc caacgatcaa ggcgagttac 3240 atgatccccc atgttgtgca aaaaagcggt tagctccttc ggtcctccga tcgttgtcag 3300 aagtaagttg gccgcagtgt tatcactcat ggttatggca gcactgcata attctcttac 3360 tgtcatgcca tccgtaagat gcttttctgt gactggtgag tactcaacca agtcattctg 3420 agaatagtgt atgcggcgac cgagttgctc ttgcccggcg tcaatacggg ataataccgc 3480 gccacatagc agaactttaa aagtgctcat cattggaaaa cgttcttcgg ggcgaaaact 3540 ctcaaggatc ttaccgctgt tgagatccag ttcgatgtaa cccactcgtg cacccaactg 3600 atcttcagca tcttttactt tcaccagcgt ttctgggtga gcaaaaacag gaaggcaaaa 3660 tgccgcaaaa aagggaataa gggcgacacg gaaatgttga atactcatac tcttcctttt 3720 tcaatattat tgaagcattt atcagggtta ttgtctcatg agcggataca tatttgaatg 3780 tatttagaaa aataaacaaa taggggttcc gcgcacattt ccccgaaaag tgccacctga 3840 cgtctaagaa accattatta tcatgacatt aacctataaa aataggcgta tcacgaggcc 3900 ctttcgtc 3908113872DNAArtificial SequenceExpression vector 11 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttttagcc gggaaacgtc 420 tggcggcgct gttggctaag tttgcggtat tgttgcggcg acatgccgac atatttgccg 480 aacgtgctgt aaaaacgact acttgaacga aagcctgccg tcagggcaat atcgagaata 540 cttttatcgg tatcgctcag taacgcgcga acgtggttga tgcgcatcgc ggtaatgtac 600 tgtttcatcg tcaattgcat gacccgctgg aatatcccca ttgcatagtt ggcgttaagt 660 ttgacgtgct cagccacatc gttgatggtc agcgcctgat catagttttc ggcaataaag 720 cccagcatct ggctaacata aaattgcgca tggcgcgaga cgctgttttt gtgtgtgcgc 780 gaggttttat tgaccagaat cggttcccag ccagagaggc taaatcgctt gagcatcagg 840 ccaatttcat caatggcgag ctggcgaatt tgctcgttcg gactgtttaa ttcctgctgc 900 cagcggcgca cttcaaacgg gctaagttgc tgtgtggcca gtgatttgat caccatgccg 960 tgagtgacgt ggttaatcag gtctttatcc agcggccagg agagaaacag atgcatcggc 1020 agattaaaaa tcgccatgct ctgacaggtt ccggtatctg ttagttggtg cggtgtacag 1080 gcccagaaca gcgtgatatg accctgattg atattcactt tttcattgtt gatcaggtat 1140 tccacatcgc catcgaaagg cacattcact tcgacctgac catgccagtg gctggtgggc 1200 atgatatgcg gtgcgcgaaa ctcaatctcc atccgctggt attccgaata cagcgacagc 1260 gggctgcggg tctgtttttc gtcgctgctg cacataaacg tatctgtatt catggatggc 1320 tctctttcct ggaatatcag aattatggca ggagtgaggg aggatgactg cgagtgggag 1380 cacggttttc accctcttcc cagaggggcg aggggactct ccgagtatca tgaggccgaa 1440 aactctgctt ttcaggtaat ttattcccat aaactcagat ttactgctgc ttcacgcagg 1500 atctgagttt atgggaatgc tcaacctgga agccggaggt tttctgcaga ttcgcctgcc 1560 atgatgaagt tattcaagca agccaggaga tctggtaccc gggtcgactc tagaggatcc 1620 ccgggtaccg agctcgaatt cgtaatcatg gtcatagctg tttcctgtgt gaaattgtta 1680 tccgctcaca attccacaca acatacgagc cggaagcata aagtgtaaag cctggggtgc 1740 ctaatgagtg agctaactca cattaattgc gttgcgctca ctgcccgctt tccagtcggg 1800 aaacctgtcg tgccagctgc attaatgaat cggccaacgc gcggggagag gcggtttgcg 1860 tattgggcgc tcttccgctt cctcgctcac tgactcgctg cgctcggtcg ttcggctgcg 1920 gcgagcggta tcagctcact caaaggcggt aatacggtta tccacagaat caggggataa 1980 cgcaggaaag aacatgtgag caaaaggcca gcaaaaggcc aggaaccgta aaaaggccgc 2040 gttgctggcg tttttccata ggctccgccc ccctgacgag catcacaaaa atcgacgctc 2100 aagtcagagg tggcgaaacc cgacaggact ataaagatac caggcgtttc cccctggaag 2160 ctccctcgtg cgctctcctg ttccgaccct gccgcttacc ggatacctgt ccgcctttct 2220 cccttcggga agcgtggcgc tttctcatag ctcacgctgt aggtatctca gttcggtgta 2280 ggtcgttcgc tccaagctgg gctgtgtgca cgaacccccc gttcagcccg accgctgcgc 2340 cttatccggt aactatcgtc ttgagtccaa cccggtaaga cacgacttat cgccactggc 2400 agcagccact ggtaacagga ttagcagagc gaggtatgta ggcggtgcta cagagttctt 2460 gaagtggtgg cctaactacg gctacactag aaggacagta tttggtatct gcgctctgct 2520 gaagccagtt accttcggaa aaagagttgg tagctcttga tccggcaaac aaaccaccgc 2580 tggtagcggt ggtttttttg tttgcaagca gcagattacg cgcagaaaaa aaggatctca 2640 agaagatcct ttgatctttt ctacggggtc tgacgctcag tggaacgaaa actcacgtta 2700 agggattttg gtcatgagat tatcaaaaag gatcttcacc tagatccttt taaattaaaa 2760 atgaagtttt aaatcaatct aaagtatata tgagtaaact tggtctgaca gttaccaatg 2820 cttaatcagt gaggcaccta tctcagcgat ctgtctattt cgttcatcca tagttgcctg 2880 actccccgtc gtgtagataa ctacgatacg ggagggctta ccatctggcc ccagtgctgc 2940 aatgataccg cgagacccac gctcaccggc tccagattta tcagcaataa accagccagc 3000 cggaagggcc gagcgcagaa gtggtcctgc aactttatcc gcctccatcc agtctattaa 3060 ttgttgccgg gaagctagag taagtagttc gccagttaat agtttgcgca acgttgttgc 3120 cattgctaca ggcatcgtgg tgtcacgctc gtcgtttggt atggcttcat tcagctccgg 3180 ttcccaacga tcaaggcgag ttacatgatc ccccatgttg tgcaaaaaag cggttagctc 3240 cttcggtcct ccgatcgttg tcagaagtaa gttggccgca gtgttatcac tcatggttat 3300 ggcagcactg cataattctc ttactgtcat gccatccgta agatgctttt ctgtgactgg 3360 tgagtactca accaagtcat tctgagaata gtgtatgcgg cgaccgagtt gctcttgccc 3420 ggcgtcaata cgggataata ccgcgccaca tagcagaact ttaaaagtgc tcatcattgg 3480 aaaacgttct tcggggcgaa aactctcaag gatcttaccg ctgttgagat ccagttcgat 3540 gtaacccact cgtgcaccca actgatcttc agcatctttt actttcacca gcgtttctgg 3600 gtgagcaaaa acaggaaggc aaaatgccgc aaaaaaggga ataagggcga cacggaaatg 3660 ttgaatactc atactcttcc tttttcaata ttattgaagc atttatcagg gttattgtct 3720 catgagcgga tacatatttg aatgtattta gaaaaataaa caaatagggg ttccgcgcac 3780 atttccccga aaagtgccac ctgacgtcta agaaaccatt attatcatga cattaaccta 3840 taaaaatagg cgtatcacga ggccctttcg tc 3872123934DNAArtificial SequenceExpression vector 12 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttcaagcc gtcaattgtc 420 tgattcgtta ccaattatga caacttgacg gctacatcat tcactttttc ttcacaaccg 480 gcacggaact cgctcgggct ggccccggtg cattttttaa atacccgcga gaaatagagt 540 tgatcgtcaa aaccaacatt gcgaccgacg gtggcgatag gcatccgggt ggtgctcaaa 600 agcagcttcg cctggctgat acgttggtcc tcgcgccagc ttaagacgct aatccctaac 660 tgctggcgga aaagatgtga cagacgcgac ggcgacaagc aaacatgctg tgcgacgctg 720 gcgatatcaa aattgctgtc tgccaggtga tcgctgatgt actgacaagc ctcgcgtacc 780 cgattatcca tcggtggatg gagcgactcg ttaatcgctt ccatgcgccg cagtaacaat 840 tgctcaagca gatttatcgc cagcagctcc gaatagcgcc cttccccttg cccggcgtta 900 atgatttgcc caaacaggtc gctgaaatgc ggctggtgcg cttcatccgg gcgaaagaac 960 cccgtattgg caaatattga cggccagtta agccattcat gccagtaggc gcgcggacga 1020 aagtaaaccc actggtgata ccattcgcga gcctccggat gacgaccgta gtgatgaatc 1080 tctcctggcg ggaacagcaa aatatcaccc ggtcggcaaa caaattctcg tccctgattt 1140 ttcaccaccc cctgaccgcg aatggtgaga ttgagaatat aacctttcat tcccagcggt 1200 cggtcgataa aaaaatcgag ataaccgttg gcctcaatcg gcgttaaacc cgccaccaga 1260 tgggcattaa acgagtatcc cggcagcagg ggatcatttt gcgcttcagc catacttttc 1320 atactcccgc cattcagaga agaaaccaat tgtccatatt gcatcagaca ttgccgtcac 1380 tgcgtctttt actggctctt ctcgctaacc aaaccggtaa ccccgcttat taaaagcatt 1440 ctgtaacaaa gcgggaccaa agccatgaca aaaacgcgta acaaaagtgt ctataatcac 1500 ggcagaaaag tccacattga ttatttgcac ggcgtcacac tttgctatgc catagcattt 1560 ttatccataa gattagcgga tcctacctga cgctttttat cgcaactctc tactgtttct 1620 ccatacccgt ttttttgggc tagcaggagg aattcaccct gcaggtcgac tctagaggat 1680 ccccgggtac cgagctcgaa ttcgtaatca tggtcatagc tgtttcctgt gtgaaattgt 1740 tatccgctca caattccaca caacatacga gccggaagca taaagtgtaa agcctggggt 1800 gcctaatgag tgagctaact cacattaatt gcgttgcgct cactgcccgc tttccagtcg 1860 ggaaacctgt cgtgccagct gcattaatga atcggccaac gcgcggggag aggcggtttg 1920 cgtattgggc gctcttccgc ttcctcgctc actgactcgc tgcgctcggt cgttcggctg 1980 cggcgagcgg tatcagctca ctcaaaggcg gtaatacggt tatccacaga atcaggggat 2040 aacgcaggaa agaacatgtg agcaaaaggc cagcaaaagg ccaggaaccg taaaaaggcc 2100 gcgttgctgg cgtttttcca taggctccgc ccccctgacg agcatcacaa aaatcgacgc 2160 tcaagtcaga ggtggcgaaa cccgacagga ctataaagat accaggcgtt tccccctgga 2220 agctccctcg tgcgctctcc tgttccgacc ctgccgctta ccggatacct gtccgccttt 2280 ctcccttcgg gaagcgtggc gctttctcat agctcacgct gtaggtatct cagttcggtg 2340 taggtcgttc gctccaagct gggctgtgtg cacgaacccc ccgttcagcc cgaccgctgc 2400 gccttatccg gtaactatcg tcttgagtcc aacccggtaa gacacgactt atcgccactg 2460 gcagcagcca ctggtaacag gattagcaga gcgaggtatg taggcggtgc tacagagttc 2520 ttgaagtggt ggcctaacta cggctacact agaaggacag tatttggtat ctgcgctctg 2580 ctgaagccag ttaccttcgg aaaaagagtt ggtagctctt gatccggcaa acaaaccacc 2640 gctggtagcg gtggtttttt tgtttgcaag cagcagatta cgcgcagaaa aaaaggatct 2700 caagaagatc ctttgatctt ttctacgggg tctgacgctc agtggaacga aaactcacgt 2760 taagggattt tggtcatgag attatcaaaa aggatcttca cctagatcct tttaaattaa 2820 aaatgaagtt ttaaatcaat ctaaagtata tatgagtaaa cttggtctga cagttaccaa 2880 tgcttaatca gtgaggcacc tatctcagcg atctgtctat ttcgttcatc catagttgcc 2940 tgactccccg tcgtgtagat aactacgata cgggagggct taccatctgg ccccagtgct 3000 gcaatgatac cgcgagaccc acgctcaccg gctccagatt tatcagcaat aaaccagcca 3060 gccggaaggg ccgagcgcag aagtggtcct gcaactttat ccgcctccat ccagtctatt 3120 aattgttgcc gggaagctag agtaagtagt tcgccagtta atagtttgcg caacgttgtt 3180 gccattgcta caggcatcgt ggtgtcacgc tcgtcgtttg gtatggcttc attcagctcc 3240 ggttcccaac gatcaaggcg agttacatga tcccccatgt tgtgcaaaaa agcggttagc 3300 tccttcggtc ctccgatcgt tgtcagaagt aagttggccg cagtgttatc actcatggtt 3360 atggcagcac tgcataattc tcttactgtc atgccatccg taagatgctt ttctgtgact 3420 ggtgagtact caaccaagtc attctgagaa tagtgtatgc ggcgaccgag ttgctcttgc 3480 ccggcgtcaa tacgggataa taccgcgcca catagcagaa ctttaaaagt gctcatcatt 3540 ggaaaacgtt cttcggggcg aaaactctca aggatcttac cgctgttgag atccagttcg 3600 atgtaaccca ctcgtgcacc caactgatct tcagcatctt ttactttcac cagcgtttct 3660 gggtgagcaa aaacaggaag gcaaaatgcc gcaaaaaagg gaataagggc gacacggaaa 3720 tgttgaatac tcatactctt cctttttcaa tattattgaa gcatttatca gggttattgt 3780 ctcatgagcg gatacatatt tgaatgtatt tagaaaaata aacaaatagg ggttccgcgc 3840 acatttcccc gaaaagtgcc acctgacgtc taagaaacca ttattatcat gacattaacc 3900 tataaaaata ggcgtatcac gaggcccttt cgtc 3934135953DNAArtificial SequenceExpression vector 13 tagttattaa tagtaatcaa ttacggggtc attagttcat agcccatata tggagttccg 60 cgttacataa cttacggtaa atggcccgcc tggctgaccg cccaacgacc cccgcccatt 120 gacgtcaata atgacgtatg ttcccatagt aacgccaata gggactttcc attgacgtca 180 atgggtggag tatttacggt aaactgccca cttggcagta catcaagtgt atcatatgcc 240 aagtacgccc cctattgacg tcaatgacgg taaatggccc gcctggcatt atgcccagta 300 catgacctta tgggactttc ctacttggca gtacatctac gtattagtca tcgctattac 360 catggtgatg cggttttggc agtacatcaa tgggcgtgga tagcggtttg actcacgggg 420 atttccaagt ctccacccca ttgacgtcaa tgggagtttg ttttggcacc aaaatcaacg 480 ggactttcca aaatgtcgta acaactccgc cccattgacg caaatgggcg gtaggcgtgt 540 acggtgggag gtctatataa gcagagctgg tttagtgaac cgtcagatcc gctagcgcta 600 gtcgagctgg acggcgacgt aaacggccac aagttcagcg tgtccggcga gggcgagggc 660 gatgccacct acggcaagct gaccctgaag ttcatctgca ccaccggcaa gctgcccgtg 720 ccctggccca ccctcgtgac caccctgacc tacggcgtgc agtgcttcag ccgctacccc 780 gaccacatga agcagcacga cttcttcaag tccgccatgc ccgaaggcta cgtccaggag 840 cgcaccatct tcttcaagga cgacggcaac tacaagaccc gcgccgaggt gaagttcgag 900 ggcgacaccc tggtgaaccg catcgagctg aagggcatcg acttcaagga ggacggcaac 960 atcctggggc acaagctgga gtacaactac aacagccaca acgtctatat catggccgac 1020 aagcagaaga acggcatcaa ggtgaacttc aagatccgcc acaacatcga ggacggcagc 1080 gtgcagctcg ccgaccacta ccagcagaac acccccatcg gcgacggccc cgtgctgctg 1140 cccgacaacc actacctgag cacccagtcc gccctgagca aagaccccaa cgagaagcgc 1200 gatcacatgg tcctgctgga gttcgtgacc gccgccggga tcactctcgg catggacgag 1260 ctgtacaagt ccggactcag atctcgagct taataacaag ccgtcaattg tctgattcgt 1320 taccaattat gacaacttga cggctacatc attcactttt tcttcacaac cggcacggaa 1380 ctcgctcggg ctggccccgg tgcatttttt aaatacccgc gagaaataga gttgatcgtc 1440 aaaaccaaca ttgcgaccga cggtggcgat aggcatccgg gtggtgctca aaagcagctt 1500 cgcctggctg atacgttggt cctcgcgcca gcttaagacg ctaatcccta actgctggcg 1560 gaaaagatgt gacagacgcg acggcgacaa gcaaacatgc tgtgcgacgc tggcgatatc 1620 aaaattgctg tctgccaggt gatcgctgat gtactgacaa gcctcgcgta cccgattatc 1680 catcggtgga tggagcgact cgttaatcgc ttccatgcgc cgcagtaaca attgctcaag 1740 cagatttatc gccagcagct ccgaatagcg cccttcccct tgcccggcgt taatgatttg 1800 cccaaacagg tcgctgaaat gcggctggtg cgcttcatcc gggcgaaaga accccgtatt 1860 ggcaaatatt gacggccagt taagccattc atgccagtag gcgcgcggac gaaagtaaac 1920 ccactggtga taccattcgc gagcctccgg atgacgaccg tagtgatgaa tctctcctgg 1980 cgggaacagc aaaatatcac ccggtcggca aacaaattct cgtccctgat ttttcaccac 2040 cccctgaccg cgaatggtga gattgagaat ataacctttc attcccagcg gtcggtcgat 2100 aaaaaaatcg agataaccgt tggcctcaat cggcgttaaa cccgccacca gatgggcatt 2160 aaacgagtat cccggcagca ggggatcatt ttgcgcttca gccatacttt tcatactccc 2220 gccattcaga gaagaaacca attgtccata ttgcatcaga cattgccgtc actgcgtctt 2280 ttactggctc ttctcgctaa ccaaaccggt aaccccgctt attaaaagca ttctgtaaca 2340 aagcgggacc aaagccatga caaaaacgcg taacaaaagt gtctataatc acggcagaaa 2400 agtccacatt gattatttgc acggcgtcac actttgctat gccatagcat ttttatccat 2460 aagattagcg gatcctacct gacgcttttt atcgcaactc tctactgttt ctccataccc 2520 gtttttttgg gctagcagga ggaattcacc atggtacccg gggatcctct agagtcgacc 2580 tgcaggcatg caagcttggc ccgcgggccc gggatccacc ggatctagat aactgatcat 2640 aatcagccat accacatttg tagaggtttt acttgcttta aaaaacctcc cacacctccc 2700 cctgaacctg aaacataaaa tgaatgcaat tgttgttgtt aacttgttta ttgcagctta 2760 taatggttac aaataaagca atagcatcac aaatttcaca aataaagcat ttttttcact 2820 gcattctagt tgtggtttgt ccaaactcat caatgtatct taacgcgtaa attgtaagcg 2880 ttaatatttt gttaaaattc gcgttaaatt tttgttaaat cagctcattt tttaaccaat 2940 aggccgaaat cggcaaaatc ccttataaat caaaagaata gaccgagata gggttgagtg 3000 ttgttccagt ttggaacaag agtccactat taaagaacgt ggactccaac gtcaaagggc 3060 gaaaaaccgt ctatcagggc gatggcccac tacgtgaacc atcaccctaa tcaagttttt 3120 tggggtcgag gtgccgtaaa gcactaaatc ggaaccctaa agggagcccc cgatttagag 3180 cttgacgggg aaagccggcg aacgtggcga gaaaggaagg gaagaaagcg aaaggagcgg 3240 gcgctagggc gctggcaagt gtagcggtca cgctgcgcgt aaccaccaca cccgccgcgc 3300 ttaatgcgcc gctacagggc gcgtcaggtg gcacttttcg gggaaatgtg cgcggaaccc 3360 ctatttgttt atttttctaa atacattcaa atatgtatcc gctcatgaga caataaccct 3420 gataaatgct tcaataatat tgaaaaagga agagtcctga ggcggaaaga accagctgtg 3480 gaatgtgtgt cagttagggt gtggaaagtc cccaggctcc ccagcaggca gaagtatgca 3540 aagcatgcat ctcaattagt cagcaaccag gtgtggaaag tccccaggct ccccagcagg 3600 cagaagtatg caaagcatgc atctcaatta gtcagcaacc atagtcccgc ccctaactcc 3660 gcccatcccg cccctaactc cgcccagttc cgcccattct ccgccccatg gctgactaat 3720 tttttttatt tatgcagagg ccgaggccgc ctcggcctct gagctattcc agaagtagtg 3780 aggaggcttt tttggaggcc taggcttttg caaagatcga tcaagagaca ggatgaggat 3840 cgtttcgcat gattgaacaa gatggattgc acgcaggttc tccggccgct tgggtggaga 3900 ggctattcgg ctatgactgg gcacaacaga caatcggctg ctctgatgcc gccgtgttcc 3960 ggctgtcagc gcaggggcgc ccggttcttt ttgtcaagac cgacctgtcc ggtgccctga 4020 atgaactgca agacgaggca gcgcggctat cgtggctggc cacgacgggc gttccttgcg 4080 cagctgtgct cgacgttgtc actgaagcgg gaagggactg gctgctattg ggcgaagtgc 4140 cggggcagga tctcctgtca tctcaccttg ctcctgccga gaaagtatcc atcatggctg 4200 atgcaatgcg gcggctgcat acgcttgatc cggctacctg cccattcgac caccaagcga 4260 aacatcgcat cgagcgagca cgtactcgga tggaagccgg tcttgtcgat caggatgatc 4320 tggacgaaga gcatcagggg ctcgcgccag ccgaactgtt cgccaggctc aaggcgagca 4380 tgcccgacgg cgaggatctc gtcgtgaccc atggcgatgc ctgcttgccg aatatcatgg 4440 tggaaaatgg ccgcttttct ggattcatcg actgtggccg gctgggtgtg gcggaccgct 4500 atcaggacat agcgttggct acccgtgata ttgctgaaga gcttggcggc gaatgggctg 4560 accgcttcct cgtgctttac ggtatcgccg ctcccgattc gcagcgcatc gccttctatc 4620 gccttcttga cgagttcttc tgagcgggac tctggggttc gaaatgaccg accaagcgac 4680 gcccaacctg ccatcacgag atttcgattc caccgccgcc ttctatgaaa ggttgggctt 4740 cggaatcgtt ttccgggacg ccggctggat gatcctccag cgcggggatc tcatgctgga 4800 gttcttcgcc caccctaggg ggaggctaac tgaaacacgg aaggagacaa taccggaagg 4860 aacccgcgct atgacggcaa taaaaagaca gaataaaacg cacggtgttg ggtcgtttgt 4920 tcataaacgc ggggttcggt cccagggctg gcactctgtc gataccccac cgagacccca 4980 ttggggccaa tacgcccgcg tttcttcctt ttccccaccc caccccccaa gttcgggtga 5040 aggcccaggg ctcgcagcca acgtcggggc ggcaggccct gccatagcct caggttactc 5100 atatatactt tagattgatt taaaacttca tttttaattt aaaaggatct aggtgaagat 5160 cctttttgat aatctcatga ccaaaatccc ttaacgtgag ttttcgttcc actgagcgtc 5220 agaccccgta gaaaagatca aaggatcttc ttgagatcct ttttttctgc gcgtaatctg 5280 ctgcttgcaa acaaaaaaac caccgctacc agcggtggtt tgtttgccgg atcaagagct 5340 accaactctt tttccgaagg taactggctt cagcagagcg cagataccaa atactgtcct 5400 tctagtgtag ccgtagttag gccaccactt caagaactct gtagcaccgc ctacatacct 5460 cgctctgcta atcctgttac cagtggctgc tgccagtggc gataagtcgt gtcttaccgg 5520 gttggactca agacgatagt taccggataa ggcgcagcgg tcgggctgaa cggggggttc 5580 gtgcacacag cccagcttgg agcgaacgac ctacaccgaa ctgagatacc tacagcgtga 5640 gctatgagaa agcgccacgc ttcccgaagg gagaaaggcg gacaggtatc cggtaagcgg 5700 cagggtcgga acaggagagc gcacgaggga gcttccaggg ggaaacgcct ggtatcttta 5760 tagtcctgtc gggtttcgcc acctctgact tgagcgtcga tttttgtgat gctcgtcagg 5820 ggggcggagc ctatggaaaa acgccagcaa cgcggccttt ttacggttcc tggccttttg 5880 ctggcctttt gctcacatgt tctttcctgc gttatcccct gattctgtgg ataaccgtat 5940 taccgccatg cat 5953141380DNARat 14 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcaggt 60 cgacatggca accacgcacg cgcagggcca cccgccagtc ttggggaatg atactctccg 120 ggaacattat gattacgtgg ggaagctggc aggcaggctg cgggatcccc ctgagggtag 180 caccctcatc accaccatcc tcttcttggt cacctgtagc ttcatcgtct tggagaacct 240 gatggttttg attgccatct ggaaaaacaa taaatttcat aaccgcatgt actttttcat 300 cggcaacttg gctctctgcg acctgctggc cggcatagcc tacaaggtca acattctgat 360 gtccggtagg aagacgttca gcctgtctcc aacagtgtgg ttcctcaggg agggcagtat 420 gttcgtagcc ctgggcgcat ccacatgcag cttattggcc attgccattg agcggcacct 480 gaccatgatc aagatgaggc cgtacgacgc caacaagaag caccgcgtgt tccttctgat 540 tgggatgtgc tggctaattg ccttctcgct gggtgccctg cccatcctgg gctggaactg 600 cctggaaaac tttcccgact gctctaccat cttgcccctc tactccaaga aatacattgc 660 ctttctcatc agcatcttca tagccattct ggtgaccatc gtcatcttgt acgcgcgcat 720 ctacttcctg gtcaagtcca gcagccgcag ggtggccaac cacaactccg agagatccat 780 ggcccttctg cggaccgtag tgatcgtggt gagcgtgttc atcgcctgtt ggtcccccct 840 tttcatcctc ttcctcatcg atgtggcctg cagggcgaag gagtgctcca tcctcttcaa 900 gagtcagtgg ttcatcatgc tggctgtcct caactcggcc atgaaccctg tcatctacac 960 gctggccagc aaagagatgc ggcgtgcttt cttccggttg gtgtgcggct gtctggtcaa 1020 gggcaagggg acccaggcct ccccgatgca gcctgctctt gacccgagca gaagtaaatc 1080 aagctccagt aacaacagca gcagccactc tccaaaggtc aaggaagacc tgccccatgt 1140 ggctacctct tcctgcgtta ctgacaaaac gaggtcgctt cagaatgggg tcctctgcaa 1200 gaagggcaat tctgcagata tccagcacag tggcggccgc tcgagtctag agggcccgcg 1260 gttcgaaggt aagcctatcc ctaaccctct cctcggtctc gattctacgc gtaccggtca 1320 tcatcaccat caccattgat aaggtaccga gctcgaattc gtaatcatgg tcatagctgt 1380151320DNAHomo sapien 15 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcaggt 60 cgacatgggg caacccggga acggcagcgc cttcttgctg gcacccaatg gaagccatgc 120 gccggaccac gacgtcacgc agcaaaggga cgaggtgtgg gtggtgggca tgggcatcgt 180 catgtctctc atcgtcctgg ccatcgtgtt tggcaatgtg ctggtcatca cagccattgc 240 caagttcgag cgtctgcaga cggtcaccaa ctacttcatc acttcactgg cctgtgctga 300 tctggtcatg ggcctagcag tggtgccctt tggggccgcc catattctta tgaaaatgtg 360 gacttttggc aacttctggt gcgagttttg gacttccatt gatgtgctgt gcgtcacggc 420 cagcattgag accctgtgcg tgatcgcagt ggatcgctac tttgccatta cttcaccttt 480 caagtaccag agcctgctga ccaagaataa ggcccgggtg atcattctga tggtgtggat 540 tgtgtcaggc cttayctcct tcttgcccat tcagatgcac tggtacaggg ccacccacca 600 ggaagccatc aactgctatg ccaatgagac ctgctgtgac ttcttcacga accaagccta 660 tgccattgcc tcttccatcg tgtccttcta cgttcccctg gtgatcatgg tcttcgtcta 720 ctccagggtc tttcaggagg ccaaaaggca gctccagaag attgacaaat ctgagggccg 780 cttccatgtc cagaacctta gccaggtgga gcaggatggg cggacggggc atggactccg 840 cagatcttcc aagttctgct tgaaggagca caaagccctc aagacgttag gcatcatcat 900 gggcactttc accctctgct ggctgccctt cttcatcgtt aacattgtgc atgtgatcca 960 ggataacctc atccgtaagg aagtttacat cctcctaaat tggataggct atgtcaattc 1020 tggtttcaat ccccttatct actgccggag cccagatttc aggattgcct tccaggagct 1080 tctgtgcctg cgcaggtctt ctttgaaggc ctatggcaat ggctactcca gcaacggcaa 1140 cacaggggag cagagtggat atcacgtgga acaggagaaa gaaaataaac tgctgtgtga 1200 agacctccca ggcacggaag actttgtggg ccatcaaggt actgtgccta gcgataacat 1260 tgattcacaa gggaggaatt gtagtacaaa tgactcactg ctataataag gatccccggg 13201652DNAArtificial SequenceCloning primer 16 aattggtacc tcaatgatga tgatgatgat gcttgcagag gaccccattc tg 52171320DNAHomo sapien 17 tcgcaactct ctactgtttc tccatacccg tttttttggg ctagcaggag gaattcacca 60 tggatagtgt gtgtccccaa ggaaaatata tccaccctca aaataattcg atttgctgta 120 ccaagtgcca caaaggaacc tacttgtaca atgactgtcc aggcccgggg caggatacgg 180 actgcaggga gtgtgagagc ggctccttca ccgcttcaga aaaccacctc agacactgcc 240 tcagctgctc caaatgccga aaggaaatgg gtcaggtgga gatctcttct tgcacagtgg 300 accgggacac cgtgtgtggc tgcaggaaga accagtaccg gcattattgg agtgaaaacc 360 ttttccagtg cttcaattgc agcctctgcc tcaatgggac cgtgcacctc tcctgccagg 420 agaaacagaa caccgtgtgc acctgccatg caggtttctt tctaagagaa aacgagtgtg 480 tctcctgtag taactgtaag aaaagcctgg agtgcacgaa gttgtgccta ccccagattg 540 agaatgttaa gggcactgag gactcaggca ccacagtgct gttgcccctg gtcattttct 600 ttggtctttg ccttttatcc ctcctcttca ttggtttaat gtatcgctac caacggtgga 660 agtccaagct ctactccatt gtttgtggga aatcgacacc tgaaaaagag ggggagcttg 720 aaggaactac tactaagccc ctggccccaa acccaagctt cagtcccact ccaggcttca 780 cccccaccct gggcttcagt cccgtgccca gttccacctt cacctccagc tccacctata 840 cccccggtga ctgtcccaac tttgcggctc cccgcagaga ggtggcacca ccctatcagg 900 gggctgaccc catccttgcg acagccctcg cctccgaccc catccccaac ccccttcaga 960 agtgggagga cagcgcccac aagccacaga gcctagacac tgatgacccc gcgacgctgt 1020 acgccgtggt ggagaacgtg cccccgttgc gctggaagga attcgtgcgg cgcctagggc 1080 tgagcgacca cgagatcgat cggctggagc tgcagaacgg gcgctgcctg cgcgaggcgc 1140 aatacagcat gctggcgacc tggaggcggc gcacgccgcg gcgcgaggcc acgctggagc 1200 tgctgggacg cgtgctccgc gacatggacc tgctgggctg cctggaggac atcgaggagg 1260 cgctttgcgg ccccgccgcc ctcccgcccg cgcccagtct tctcagatga tctagagtcg 1320181380DNAHomo sapien 18 ccatacccgt ttttttgggc tagcaggagg aattcaccct gcaggtcgac atgggactgg 60 tccctcacct aggggacagg gagaagagag atagtgtgtg tccccaagga aaatatatcc 120 accctcaaaa taattcgatt tgctgtacca agtgccacaa aggaacctac ttgtacaatg 180 actgtccagg cccggggcag gatacggact gcagggagtg tgagagcggc tccttcaccg 240 cttcagaaaa ccacctcaga cactgcctca gctgctccaa atgccgaaag gaaatgggtc 300 aggtggagat ctcttcttgc acagtggacc gggacaccgt gtgtggctgc aggaagaacc 360 agtaccggca ttattggagt gaaaaccttt tccagtgctt caattgcagc ctctgcctca 420 atgggaccgt gcacctctcc tgccaggaga aacagaacac cgtgtgcacc tgccatgcag 480 gtttctttct aagagaaaac gagtgtgtct cctgtagtaa ctgtaagaaa agcctggagt 540 gcacgaagtt gtgcctaccc cagattgaga atgttaaggg cactgaggac tcaggcacca 600 cagtgctgtt gcccctggtc attttctttg gtctttgcct tttatccctc ctcttcattg 660 gtttaatgta tcgctaccaa cggtggaagt ccaagctcta ctccattgtt tgtgggaaat 720 cgacacctga aaaagagggg gagcttgaag gaactactac taagcccctg gccccaaacc 780 caagcttcag tcccactcca ggcttcaccc ccaccctggg cttcagtccc gtgcccagtt 840 ccaccttcac ctccagctcc acctataccc ccggtgactg tcccaacttt gcggctcccc 900 gcagagaggt ggcaccaccc tatcaggggg ctgaccccat ccttgcgaca gccctcgcct 960 ccgaccccat ccccaacccc cttcagaagt gggaggacag cgcccacaag ccacagagcc 1020 tagacactga tgaccccgcg acgctgtacg ccgtggtgga gaacgtgccc ccgttgcgct 1080 ggaaggaatt cgtgcggcgc ctagggctga gcgaccacga gatcgatcgg ctggagctgc 1140 agaacgggcg ctgcctgcgc gaggcgcaat acagcatgct ggcgacctgg aggcggcgca 1200 cgccgcggcg cgaggccacg ctggagctgc tgggacgcgt gctccgcgac atggacctgc 1260 tgggctgcct ggaggacatc gaggaggcgc tttgcggccc cgccgccctc ccgcccgcgc 1320 ccagtcttct cagataataa ggtaccgagc tcgaattcgt aatcatggtc atagctgttt 138019780DNAHomo sapien 19 gtttttttgg gctagcagga ggaattcatg agcactgaaa gcatgatccg ggacgtggag 60 ctggccgagg aggcgctccc caagaagaca ggggggcccc agggctccag gcggtgcttg 120 ttcctcagcc tcttctcctt cctgatcgtg gcaggcgcca ccacgctctt ctgcctgctg 180 cactttggag tgatcggccc ccagagggaa gagttcccca gggacctctc tctaatcagc 240 cctctggccc aggcagtcag atcatcttct cgaaccccga gtgacaagcc tgtagcccat 300 gttgtagcaa accctcaagc tgaggggcag ctccagtggc tgaaccgccg ggccaatgcc 360 ctcctggcca atggcgtgga gctgagagat aaccagctgg tggtgccatc agagggcctg 420 tacctcatct actcccaggt cctcttcaag ggccaaggct gcccctccac ccatgtgctc 480 ctcacccaca ccatcagccg catcgccgtc tcctaccaga ccaaggtcaa cctcctctct 540 gccatcaaga gcccctgcca gagggagacc ccagaggggg ctgaggccaa gccctggtat 600 gagcccatct atctgggagg ggtcttccag ctggagaagg gtgaccgact cagcgctgag 660 atcaatcggc ccgactatct cgactttgcc gagtctgggc aggtctactt tgggatcatt 720 gccctgtgat aagcttggcc cgcgggcccg ggatccaccg gatctagata actgatcata 78020300DNAArtificial SequenceGene encoding a fusion protein 20 gtttttttgg gctagcagga ggaattcacc atggtaccat gaacttgggg aatcgactgt 60 ttattctgat agcggtctta cttcccctcg cagtattact gctcaatagt gactctgaat 120 gtcccctgtc ccacgatggg tactgcctcc atgatggtgt gtgcatgtat attgaagcat 180 tggacaagta tgcatgcaac tgtgttgttg gctacatcgg ggagcgatgt cagtaccgag 240 acctgaagtg gtgggaactg cgctaataag cttggcccgc gggcccggga tccaccggat 300211620DNAArtificial SequenceGene encoding a fusion protein 21 gtttttttgg gctagcagga ggaattcacc atgaacttgg ggaatcgact gtttattctg 60 atagcggtct tacttcccct cgcagtatta ctgctctcat tcacattgag cgtcaccgtt 120 cagcagcctc agttgacatt aacggcggcc gtcattggtg atggcgcacc ggctaatggg 180 aaaactgcaa tcaccgttga gttcaccgtt gctgattttg aggggaaacc cttagccggg 240 caggaggtgg tgataaccac caataatggt gcgctaccga ataaaatcac ggaaaagaca 300 gatgcaaatg gcgtcgcgcg cattgcatta accaatacga cagatggcgt gacggtagtc 360 acagcagaag tggaggggca acggcaaagt gttgataccc actttgttaa gggtactatc 420 gcggcggata aatccactct ggctgcggta ccgacatcta tcatcgctga tggtctaatg 480 gcttcaacca tcacgttgga gttgaaggat acctatgggg acccgcaggc tggcgcgaat 540 gtggcttttg acacaacctt aggcaatatg ggcgttatca cggatcacaa tgacggcact 600 tatagcgcac cattgaccag taccacgttg ggggtagcaa cagtaacggt gaaagtggat 660 ggggctgcgt tcagtgtgcc gagtgtgacg gttaatttca cggcagatcc tattccagat 720 gctggccgct ccagtttcac cgtctccaca ccggatatct tggctgatgg cacgatgagt 780 tccacattat cctttgtccc tgtcgataag aatggccatt ttatcagtgg gatgcagggc 840 ttgagtttta ctcaaaacgg tgtgccggtg agtattagcc ccattaccga gcagccagat 900 agctataccg cgacggtggt tgggaatagt gtcggtgatg tcacaatcac gccgcaggtt 960 gataccctga tactgagtac attgcagaaa aaaatatccc tattcccggt acctacgctg 1020 accggtattc tggttaacgg gcaaaatttc gctacggata aagggttccc gaaaacgatc 1080 tttaaaaacg ccacattcca gttacagatg gataacgatg ttgctaataa tactcagtat 1140 gagtggtcgt cgtcattcac acccaatgta tcggttaacg atcagggtca ggtgacgatt 1200 acctaccaaa cctatagcga agtggctgtg acggcgaaaa gtaaaaaatt cccaagttat 1260 tcggtgagtt atcggttcta cccaaatcgg tggatatacg atggcggcag atcgctggta 1320 tccagtctcg aggccagcag acaatgccaa ggttcagata tgtctgcggt tcttgaatcc 1380 tcacgtgcaa ccaacggaac gcgtgcgcct gacgggacat tgtggggcga gtgggggagc 1440 ttgaccgcgt atagttctga ttggcaatct ggtgaatatt gggtcaaaaa gaccagcacg 1500 gattttgaaa ccatgaatat ggacacaggc gcactgcaac cagggcctgc atacttggcg 1560 ttcccgctct gtgcgctgtc aatataactg caggcatgca agcttggccc gcgggcccgg 162022208DNAE. coli 22 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gtcacggccg agacttatag tcgctttgtt tttatttttt aatgtatttg tacatggaga 120 aaataaagtg aaacaaagca ctattgcact ggcactctta ccgttactgt ttacccctgt 180 gacaaaagcc cggacaccag aatctaga 208231546DNAE. coli 23 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gtcacggccg agacttatag tcgctttgtt tttatttttt aatgtatttg tacatggaga 120 aaataaagtg aaacaaagca ctattgcact ggcactctta ccgttactgt ttacccctgt 180 gacaaaagcc cggacaccag aaatgcctgt tctggaaaac cgggctgctc agggcgatat 240 tactgcaccc ggcggtgctc gccgtttaac gggtgatcag actgccgctc tgcgtgattc 300 tcttagcgat aaacctgcaa aaaatattat tttgctgatt ggcgatggga tgggggactc 360 ggaaattact gccgcacgta attatgccga aggtgcgggc ggctttttta aaggtataga 420 tgccttaccg cttaccgggc aatacactca ctatgcgctg aataaaaaaa ccggcaaacc 480 ggactacgtc accgactcgg ctgcatcagc aaccgcctgg tcaaccggtg tcaaaaccta 540 taacggcgcg ctgggcgtcg atattcacga aaaagatcac ccaacgattc tggaaatggc 600 aaaagccgca ggtctggcga ccggtaacgt ttctaccgca gagttgcagg atgccacgcc 660 cgctgcgctg gtggcacatg tgacctcgcg caaatgctac ggtccgagcg cgaccagtga 720 aaaatgtccg ggtaacgctc tggaaaaagg cggaaaagga tcgattaccg aacagctgct 780 taacgctcgt gccgacgtta cgcttggcgg cggcgcaaaa acctttgctg aaacggcaac 840 cgctggtgaa tggcagggaa aaacgctgcg tgaacaggca caggcgcgtg gttatcagtt 900 ggtgagcgat gctgcctcac tgaattcggt gacggaagcg aatcagcaaa aacccctgct 960 tggcctgttt gctgacggca atatgccagt gcgctggcta ggaccgaaag caacgtacca 1020 tggcaatatc gataagcccg cagtcacctg tacgccaaat ccgcaacgta atgacagtgt 1080 accaaccctg gcgcagatga ccgacaaagc cattgaattg ttgagtaaaa atgagaaagg 1140 ctttttcctg caagttgaag gtgcgtcaat cgataaacag gatcatgctg cgaatccttg 1200 tgggcaaatt ggcgagacgg tcgatctcga tgaagccgta caacgggcgc tggaattcgc 1260 taaaaaggag ggtaacacgc tggtcatagt caccgctgat cacgcccacg ccagccagat 1320 tgttgcgccg gataccaaag ctccgggcct cacccaggcg ctaaatacca aagatggcgc 1380 agtgatggtg atgagttacg ggaactccga agaggattca caagaacata ccggcagtca 1440 gttgcgtatt gcggcgtatg gcccgcatgc cgccaatgtt gttggactga ccgaccagac 1500 cgatctcttc tacaccatga aagccgctct ggggctgaaa tctaga 154624148DNAE. coli 24 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gaaaataaaa acaggtgcac gcatcctcgc attatccgca ttaacgacga tgatgttttc 120 cgcctcggct ctcgccaaaa tctctaga 148251174DNAE. coli 25 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gaaaataaaa acaggtgcac gcatcctcgc attatccgca ttaacgacga tgatgttttc 120 cgcctcggct ctcgccaaaa tcgaagaagg taaactggta atctggatta acggcgataa 180 aggctataac ggtctcgctg aagtcggtaa gaaattcgag aaagataccg gaattaaagt 240 caccgttgag catccggata aactggaaga gaaattccca caggttgcgg caactggcga 300 tggccctgac attatcttct gggcacacga ccgctttggt ggctacgctc aatctggcct 360 gttggctgaa atcaccccgg acaaagcgtt ccaggacaag ctgtatccgt ttacctggga 420 tgccgtacgt tacaacggca agctgattgc ttacccgatc gctgttgaag cgttatcgct 480 gatttataac aaagatctgc tgccgaaccc gccaaaaacc tgggaagaga tcccggcgct 540 ggataaagaa ctgaaagcga aaggtaagag cgcgctgatg ttcaacctgc aagaaccgta 600 cttcacctgg ccgctgattg ctgctgacgg gggttatgcg ttcaagtatg aaaacggcaa 660 gtacgacatt aaagacgtgg gcgtggataa cgctggcgcg aaagcgggtc tgaccttcct 720 ggttgacctg attaaaaaca aacacatgaa tgcagacacc gattactcca tcgcagaagc 780 tgcctttaat aaaggcgaaa cagcgatgac catcaacggc ccgtgggcat ggtccaacat 840 cgacaccagc aaagtgaatt atggtgtaac ggtactgccg accttcaagg gtcaaccatc 900 caaaccgttc gttggcgtgc tgagcgcagg tattaacgcc gccagtccga acaaagagct 960 ggcgaaagag ttcctcgaaa actatctgct gactgatgaa ggtctggaag cggttaataa 1020 agacaaaccg ctgggtgccg tagcgctgaa gtcttacgag gaagagttgg cgaaagatcc 1080 acgtattgcc gccaccatgg aaaacgccca gaaaggtgaa atcatgccga acatcccgca 1140 gatgtccgct ttctggtatg ccgtgcgttc taga 1174263840DNAArtificial SequenceGene encoding a fusion protein 26 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 60 atacgcgaca gcgcgcaata accgttctcg actcataaaa gtgatgccgc tataatgccg 120 cgtcctattt gaatgctttc gggatgattc tggtaacagg gaatgtgatt gattataaga 180 acatcccggt tccgcgaagc caacaacctg tgcttgcggg gtaagagttg accgagcact 240 gtgatttttt gaggtaacaa gatgcaagtt tcagttgaaa ccactcaagg ccttggccgc 300 cgtgtaacga ttactatcgc tgctgacagc atcgagaccg ctgttaaaag cgagctggtc 360 aacgttgcga aaaaagtacg tattgacggc ttccgcaaag gcaaagtgcc aatgaatatc 420 gttgctcagc gttatggcgc gtctgtacgc caggacgttc tgggtgacct gatgagccgt 480 aacttcattg acgccatcat taaagaaaaa atcaatccgg ctggcgcacc gacttatgtt 540 ccgggcgaat acaagctggg tgaagacttc acttactctg tagagtttga agtttatccg 600 gaagttgaac tgcagggtct ggaagcgatc gaagttgaaa aaccgatcgt tgaagtgacc 660 gacgctgacg ttgacggcat gctggatact ctgcgtaaac agcaggcgac ctggaaagaa 720 aaagacggcg ctgttgaagc agaagaccgc gtaaccatcg acttcaccgg ttctgtagac 780 ggcgaagagt tcgaaggcgg taaagcgtct gatttcgtac tggcgatggg ccagggtcgt 840 atgatcccgg gctttgaaga cggtatcaaa ggccacaaag ctggcgaaga gttcaccatc 900 gacgtgacct tcccggaaga ataccacgca gaaaacctga aaggtaaagc agcgaaattc 960 gctatcaacc tgaagaaagt tgaagagcgt gaactgccgg aactgactgc agaattcatc 1020 aaacgtttcg gcgttgaaga tggttccgta gaaggtctgc gcgctgaagt gcgtaaaaac 1080 atggagcgcg agctgaagag cgccatccgt aaccgcgtta agtctcaggc gatcgaaggt 1140 ctggtaaaag ctaacgacat cgacgtaccg gctgcgctga tcgacagcga aatcgacgtt 1200 ctgcgtcgcc aggctgcaca gcgtttcggt ggcaacgaaa aacaagctct ggaactgccg 1260 cgcgaactgt tcgaagaaca ggctaaacgc cgcgtagttg ttggcctgct gctgggcgaa 1320 gttatccgca ccaacgagct gaaagctgac gaagagcgcg tgaaaggcct gatcgaagag 1380 atggcttctg cgtacgaaga tccgaaagaa gttatcgagt tctacagcaa aaacaaagaa 1440 ctgatggaca acatgcgcaa tgttgctctg gaagaacagg ctgttgaagc tgtactggcg 1500 aaagcgaaag tgactgaaaa agaaaccact ttcaacgagc tgatgaacca gcaggcgtaa 1560 taataatcta gaggtagcac aatcagattc gcttatgacg gcgatgaaga aattgcgatg 1620 aaatgtgagg tgaatcaggg ttttcacccg attttgtgct gatcagaatt ttttttcttt 1680 ttcccccttg aaggggcgaa gcctcatccc catttctctg gtcaccagcc gggaaaccac 1740 gtaagctccg gcgtcaccca taacagatac ggactttctc aaaggagagt tatcaatgaa 1800 tattcgtcca ttgcatgatc gcgtgatcgt caagcgtaaa gaagttgaaa ctaaatctgc 1860 tggcggcatc gttctgaccg gctctgcagc ggctaaatcc acccgcggcg aagtgctggc 1920 tgtcggcaat ggccgtatcc ttgaaaatgg cgaagtgaag ccgctggatg tgaaagttgg 1980 cgacatcgtt attttcaacg atggctacgg tgtgaaatct gagaagatcg acaatgaaga 2040 agtgttgatc atgtccgaaa gcgacattct ggcaattgtt gaagcgtaat ccgcgcacga 2100 cactgaacat acgaatttaa ggaataaaga taatggcagc taaagacgta aaattcggta 2160 acgacgctcg tgtgaaaatg ctgcgcggcg taaacgtact ggcagatgca gtgaaagtta 2220 ccctcggtcc aaaaggccgt aacgtagttc tggataaatc tttcggtgca ccgaccatca 2280 ccaaagatgg tgtttccgtt gctcgtgaaa tcgaactgga agacaagttc gaaaatatgg 2340 gtgcgcagat ggtgaaagaa gttgcctcta aagcaaacga cgctgcaggc gacggtacca 2400 ccactgcaac cgtactggct caggctatca tcactgaagg tctgaaagct gttgctgcgg 2460 gcatgaaccc gatggacctg aaacgtggta tcgacaaagc ggttaccgct gcagttgaag 2520 aactgaaagc gctgtccgta ccatgctctg actctaaagc gattgctcag gttggtacca 2580 tctccgctaa ctccgacgaa accgtaggta aactgatcgc tgaagcgatg gacaaagtcg 2640 gtaaagaagg cgttatcacc gttgaagacg gtaccggtct gcaggacgaa ctggacgtgg 2700 ttgaaggtat gcagttcgac cgtggctacc tgtctcctta cttcatcaac aagccggaaa 2760 ctggcgcagt agaactggaa agcccgttca tcctgctggc tgacaagaaa atctccaaca 2820 tccgcgaaat gctgccggtt ctggaagctg ttgccaaagc aggcaaaccg ctgctgatca 2880 tcgctgaaga tgtagaaggc gaagcgctgg caactctggt tgttaacacc atgcgtggca 2940 tcgtgaaagt cgctgcggtt aaagcaccgg gcttcggcga tcgtcgtaaa gctatgctgc 3000 aggatatcgc aaccctgact ggcggtaccg tgatctctga agagatcggt atggagctgg 3060 aaaaagcaac cctggaagac ctgggtcagg ctaaacgtgt tgtgatcaac aaagacacca 3120 ccactatcat cgatggcgtg ggtgaagaag ctgcaatcca gggccgtgtt gctcagatcc 3180 gtcagcagat tgaagaagca acttctgact acgaccgtga aaaactgcag gaacgcgtag 3240 cgaaactggc aggcggcgtt gcagttatca aagtgggtgc tgctaccgaa gttgaaatga 3300 aagagaaaaa agcacgcgtt gaagatgccc tgcacgcgac ccgtgctgcg gtagaagaag 3360 gcgtggttgc tggtggtggt gttgcgctga tccgcgtagc gtctaaactg gctgacctgc 3420 gtggtcagaa cgaagaccag aacgtgggta tcaaagttgc actgcgtgca atggaagctc 3480 cgctgcgtca gatcgtattg aactgcggcg aagaaccgtc tgttgttgct aacaccgtta 3540 aaggcggcga cggcaactac ggttacaacg cagcaaccga agaatacggc aacatgatcg 3600 acatgggtat cctggatcca accaaagtaa ctcgttctgc tctgcagtac gcagcttctg 3660 tggctggcct gatgatcacc accgaatgca tggttaccga cctgccgaaa aacgatgcag 3720 ctgacttagg cgctgctggc ggtatgggcg gcatgggtgg catgggcggc atgatgtaat 3780 aataagcttg catgcctgca ggtcgactct agaggatccc cgggtaccga gctcgaattc 384027480DNAArtificial SequenceGene encoding a fusion protein 27 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag caggatcaca ttctgcagat 60 gatcgaagcc cgctctagac tcgagagcga taaaattatt cacctgactg acgacagttt 120 tgacacggat gtactcaaag cggacggggc gatcctcgtc gatttctggg cagagtggtg 180 cggtccgtgc aaaatgatcg ccccgattct ggatgaaatc gctgacgaat atcagggcaa 240 actgaccgtt gcaaaactga acatcgatca aaaccctggc actgcgccga aatatggcat 300 ccgtggtatc ccgactctgc tgctgttcaa aaacggtgaa gtggcggcaa ccaaagtggg 360 tgcactgtct aaaggtcagt tgaaagagtt cctcgacgct aacctggcgc tcgaggatta 420 taaagatcat gatggcgatt ataaagatca tgatgattaa taaggatccc cgggtaccga 480281140DNARat 28 atggcaacca cgcacgcgca ggggcacccg ccagtcttgg ggaatgatac tctccgggaa 60 cattatgatt acgtggggaa gctggcaggc aggctgcggg atccccctga gggtagcacc 120 ctcatcacca ccatcctctt cttggtcacc tgtagcttca tcgtcttgga gaacctgatg 180 gttttgattg ccatctggaa aaacaataaa tttcataacc gcatgtactt tttcatcggc 240 aacttggctc tctgcgacct gctggccggc atagcctaca aggtcaacat tctgatgtcc 300 ggtaggaaga cgttcagcct gtctccaaca gtgtggttcc tcagggaggg cagtatgttc 360 gtagccctgg gcgcatccac atgcagctta ttggccattg ccattgagcg gcacctgacc 420 atgatcaaga tgaggccgta cgacgccaac aagaagcacc gcgtgttcct tctgattggg 480 atgtgctggc taattgcctt ctcgctgggt gccctgccca tcctgggctg gaactgcctg 540 gagaactttc ccgactgctc taccatcttg cccctctact ccaagaaata cattgccttt 600 ctcatcagca tcttcacagc cattctggtg accatcgtca tcttgtacgc gcgcatctac 660 ttcctggtca agtccagcag ccgcagggtg gccaaccaca actccgagag atccatggcc 720 cttctgcgga ccgtagtgat cgtggtgagc gtgttcatcg cctgttggtc cccccttttc 780 atcctcttcc tcatcgatgt ggcctgcagg gcgaaggagt gctccatcct cttcaagagt 840 cagtggttca tcatgctggc tgtcctcaac tcggccatga accctgtcat ctacacgctg 900 gccagcaaag agatgcggcg tgctttcttc cggttggtgt gcggctgtct ggtcaagggc 960 aaggggaccc aggcctcccc gatgcagcct gctcttgacc cgagcagaag taaatcaagc 1020 tccagtaaca acagcagcag ccactctcca aaggtcaagg aagacctgcc ccatgtggct 1080 acctcttcct gcgtcactga caaaacgagg tcgcttcaga atggggtcct ctgcaagtga 114029379PRTRat 29 Met Ala Thr Thr His Ala Gln Gly His Pro Pro Val Leu Gly Asn Asp 1 5 10 15 Thr Leu Arg Glu His Tyr Asp Tyr Val Gly Lys Leu Ala Gly Arg Leu 20 25 30 Arg Asp Pro Pro Glu Gly Ser Thr Leu Ile Thr Thr Ile Leu Phe Leu 35 40 45 Val Thr Cys Ser Phe Ile Val Leu Glu Asn Leu Met Val Leu Ile Ala 50 55 60 Ile Trp Lys Asn Asn Lys Phe His Asn Arg Met Tyr Phe Phe Ile Gly 65 70 75 80 Asn Leu Ala Leu Cys Asp Leu Leu Ala Gly Ile Ala Tyr Lys Val Asn 85 90 95 Ile Leu Met Ser Gly Arg Lys Thr Phe Ser Leu Ser Pro Thr Val Trp 100 105 110 Phe Leu Arg Glu Gly Ser Met Phe Val Ala Leu Gly Ala Ser Thr Cys 115 120 125 Ser Leu Leu Ala Ile Ala Ile Glu Arg His Leu Thr Met Ile Lys Met 130 135 140 Arg Pro Tyr Asp Ala Asn Lys Lys His Arg Val Phe Leu Leu Ile Gly 145 150 155 160 Met Cys Trp Leu Ile Ala Phe Ser Leu Gly Ala Leu Pro Ile Leu Gly 165 170 175 Trp Asn Cys Leu Glu Asn Phe Pro Asp Cys Ser Thr Ile Leu Pro Leu 180 185 190 Tyr Ser Lys Lys Tyr Ile Ala Phe Leu Ile Ser Ile Phe Thr Ala Ile 195 200 205 Leu Val Thr Ile Val Ile Leu Tyr Ala Arg Ile Tyr Phe Leu Val Lys 210 215 220 Ser Ser Ser Arg Arg Val Ala Asn His Asn Ser Glu Arg Ser Met Ala 225 230 235 240 Leu Leu Arg Thr Val Val Ile Val Val Ser Val Phe Ile Ala Cys Trp 245 250 255 Ser Pro Leu Phe Ile Leu Phe Leu Ile Asp Val Ala Cys Arg Ala Lys 260 265 270 Glu Cys Ser Ile Leu Phe Lys Ser Gln Trp Phe Ile Met Leu Ala Val 275 280 285 Leu Asn Ser Ala Met Asn Pro Val Ile Tyr Thr Leu Ala Ser Lys Glu 290 295 300 Met Arg Arg Ala Phe Phe Arg Leu Val Cys Gly Cys Leu Val Lys Gly 305 310 315 320 Lys Gly Thr Gln Ala Ser Pro Met Gln Pro Ala Leu Asp Pro Ser Arg 325 330 335 Ser Lys Ser Ser Ser Ser Asn Asn Ser Ser Ser His Ser Pro Lys Val 340 345 350 Lys Glu Asp Leu Pro His Val Ala Thr Ser Ser Cys Val Thr Asp Lys 355 360 365 Thr Arg Ser Leu Gln Asn Gly Val Leu Cys Lys 370 3753032DNAArtificial SequenceCloning primer 30 aattgctagc tccaccagca tcccagtggt ta 323132DNAArtificial SequenceCloning primer 31 aattggatcc ttaagaagaa gaattgacgt tt 323232DNAArtificial SequenceCloning primer 32 aattggatcc agaagaagaa ttgacgtttc ca 323352DNAArtificial SequenceCloning primer 33 aattggatcc ttaatgatga tgatgatgat gagaagaaga attgacgttt cc 523424DNAArtificial SequenceCloning primer 34 ttatggcaac cacgcacgcg cagg 243521DNAArtificial SequenceCloning primer 35 agaccgtcac ttgcagagga c 213632DNAArtificial SequenceCloning primer 36 aattgctagc acgcacgcgc aggggcaccc gc 323734DNAArtificial SequenceCloning primer 37 aattggtacc tcacttgcag aggaccccat tctg 343832DNAArtificial SequenceCloning primer 38 aattgctagc acgcacgcgc aggggcaccc gc 323921DNAArtificial SequenceCloning primer 39 ggtcgccacc atggtgagca a 214031DNAArtificial SequenceCloning primer 40 ttaaggatcc ttacttgtac agctcgtcca t 314121DNAArtificial SequenceCloning primer 41 ggtcgccacc atggtgagca a 214231DNAArtificial SequenceCloning primer 42 ttaaggatcc cttgtacagc tcgtccatgc c 314325DNAArtificial SequenceCloning primer 43 ccaatggaac ttaccaatga cgcgg 254424DNAArtificial SequenceCloning primer 44 gcttgcttac gcaggaatgc tggg 244545DNAArtificial SequenceCloning primer 45 cgcggctgca gatgtttgaa ccaatggaac ttaccaatga cgcgg 454645DNAArtificial SequenceCloning primer 46 gcgcctctag attattaatc agcttgctta cgcaggaatg ctggg 454731DNAArtificial SequenceCloning primer 47 gctagactgg gcggttttat ggacagcaag c 314835DNAArtificial SequenceCloning primer 48 gcgttaataa ttcagaagaa ctcgtcaaga aggcg 354999DNAArtificial SequenceCloning primer 49 gcgcctactg acgtagttcg accgtcggac tagcgaagtt cctatacttt ctagagaata 60 ggaacttcgc tagactgggc ggttttatgg acagcaagc 9950109DNAArtificial SequenceCloning primer 50 caagatgctt tgcctttgtc tgagttgata ctggctttgg gaagttccta ttctctagaa 60 agtataggaa cttcgcgtta ataattcaga agaactcgtc aagaaggcg 1095126DNAArtificial SequenceCloning primer 51 cgttaccaat tatgacaact tgacgg 265229DNAArtificial SequenceCloning primer 52 ttaatctttc tgcgaattga gatgacgcc 295328DNAArtificial SequenceCloning primer 53 gtgagtcgat attgtctttg ttgaccag 285466DNAArtificial SequenceCloning primer 54 gcctgcattg cggcgcttca gtctccgctg catactgtcc cgttaccaat tatgacaact 60 tgacgg 665569DNAArtificial SequenceCloning primer 55 gcctgcattg cggcgcttca gtctccgctg catactgtcc ttaatctttc tgcgaattga 60 gatgacgcc 695676DNAArtificial SequenceCloning primer 56 gcctgcattg cggcgcttca gtctccgctg catactgtcc ttaataaagt gagtcgatat 60 tgtctttgtt gaccag 765766DNAArtificial SequenceCloning primer 57 gcctgcattg cggcgcttca gtctccgctg catactgtcc cgttaccaat tatgacaact 60 tgacgg 665830DNAArtificial SequenceCloning primer 58 gcctgttctg gaaaaccggg ctgctcaggg 305928DNAArtificial SequenceCloning primer 59 gcggctttca tggtgtagaa gagatcgg 286043DNAArtificial SequenceCloning primer 60 ccgcgctgca gatgcctgtt ctggaaaacc gggctgctca ggg 436158DNAArtificial SequenceCloning primer 61 gcgcctctag attattattt cagccccaga gcggctttca tggtgtagaa gagatcgg 586224DNAArtificial SequenceCloning primer 62 gtcacggccg agacttatag tcgc 246328DNAArtificial SequenceCloning primer 63 gcggctttca tggtgtagaa gagatcgg 286437DNAArtificial SequenceCloning primer 64 ccgcgctgca gatgtcacgg ccgagactta tagtcgc 376558DNAArtificial SequenceCloning primer 65 gcgcctctag attattattt cagccccaga gcggctttca tggtgtagaa gagatcgg 5866109DNAArtificial SequenceCloning primer 66 ccgcgctgca gatgaacttg gggaatcgac tgtttattct gatagcggtc ttacttcccc 60 tcgcagtatt actgctcatg cctgttctgg aaaaccgggc tgctcaggg 1096758DNAArtificial SequenceCloning primer 67 gcgcctctag attattattt cagccccaga gcggctttca tggtgtagaa gagatcgg 586824DNAArtificial SequenceCloning primer 68 gcgaattgag atgacgccac tggc 246925DNAArtificial SequenceCloning primer 69 cctgctgaat ttcattaacg accag 257048DNAArtificial SequenceCloning primer 70 cggcgaagct taattaatct ttctgcgaat tgagatgacg ccactggc 487153DNAArtificial SequenceCloning primer 71 cgccgtaatc gccgctgcag aatgtgatcc tgctgaattt cattaacgac cag 537222DNAArtificial SequenceCloning primer 72 cgcagcgctg ttcctttgct cg 227323DNAArtificial SequenceCloning primer 73 cctcattaag ataataatac tgg 237433DNAArtificial SequenceCloning primer 74 gccgcaagct tcgcagcgct gttcctttgc tcg 337547DNAArtificial SequenceCloning primer 75 ccaatgcatt ggttctgcag gactcctcat taagataata atactgg 477619DNAArtificial SequenceCloning primer 76 cgtctttagc cgggaaacg 197718DNAArtificial SequenceCloning primer 77 gcagatctcc tggcttgc 187830DNAArtificial SequenceCloning primer 78 gccgcaagct tcgtctttag ccgggaaacg 307926DNAArtificial SequenceCloning primer 79 cggtcgacgc agatctcctg gcttgc 268023DNAArtificial SequenceCloning primer 80 caagccgtca attgtctgat tcg 238122DNAArtificial SequenceCloning primer 81 ggtgaattcc tcctgctagc cc 228234DNAArtificial SequenceCloning primer 82 gcgccaagct tcaagccgtc aattgtctga ttcg 348328DNAArtificial SequenceCloning primer 83 ctgcagggtg aattcctcct gctagccc 288442DNAArtificial SequenceCloning primer 84 gcttaactcg agcttaataa caagccgtca attgtctgat tc 428534DNAArtificial SequenceCloning primer 85 gcttaaccgc gggccaagct tgcatgcctg ctcc 348626DNAArtificial SequenceCloning primer 86 ggcaaccacg cacgcgcagg gccacc 268725DNAArtificial SequenceCloning primer 87 caatggtgat ggtgatgatg accgg 258838DNAArtificial SequenceCloning primer 88 cgcggtcgac atggcaacca cgcacgcgca gggccacc 388940DNAArtificial SequenceCloning primer 89 gcgccggtac cttatcaatg gtgatggtga tgatgaccgg 409025DNAArtificial SequenceCloning primer 90 ggggcaaccc gggaacggca gcgcc 259130DNAArtificial SequenceCloning primer 91 gcagtgagtc atttgtacta caattcctcc 309237DNAArtificial SequenceCloning primer 92 cgcggtcgac atggggcaac ccgggaacgg cagcgcc 379349DNAArtificial SequenceCloning primer 93 gcgccggatc cttattatag cagtgagtca tttgtactac aattcctcc 499428DNAArtificial SequenceCloning primer 94 ggactggtcc ctcacctagg ggacaggg 289527DNAArtificial SequenceCloning primer 95 ctgagaagac tgggcgcggg cgggagg 279642DNAArtificial SequenceCloning primer 96 cgcgggtcga catgggactg gtccctcacc taggggacag gg 429744DNAArtificial SequenceCloning primer 97 gcgccggtac cttattactg agaagactgg gcgcgggcgg gagg 449816DNAArtificial SequenceCloning primer 98 gatagtgtgt gtcccc 169917DNAArtificial SequenceCloning primer 99 ctgagaagac tgggcgc 1710027DNAArtificial SequenceCloning primer 100 gggagaccat ggatagtgtg tgtcccc 2710132DNAArtificial SequenceCloning primer 101 gcctcatcta gattactgag aagactgggc gc 3210226DNAArtificial SequenceCloning primer 102 gagcactgaa agcatgatcc gggacg 2610328DNAArtificial SequenceCloning primer 103 cagggcaatg atcccaaagt agacctgc 2810439DNAArtificial SequenceCloning primer 104 ccgcggaatt catgagcact gaaagcatga tccgggacg 3910543DNAArtificial SequenceCloning primer 105 ggcgcaagct tatcacaggg caatgatccc aaagtagacc tgc 43106110DNAArtificial SequenceCloning primer 106 tctgatagcg gtcttacttc ccctcgcagt attactgctc aatagtgact ctgaatgtcc 60 cctgtcccac gatgggtact gcctccatga tggtgtgtgc atgtatattg 110107101DNAArtificial SequenceCloning primer 107 aggtctcggt actgacatcg ctccccgatg tagccaacaa cacagttgca tgcatacttg 60 tccaatgctt caatatacat gcacacacca tcatggaggc a 10110863DNAArtificial SequenceCloning primer 108 ccgcgggtac catgaacttg gggaatcgac tgtttattct gatagcggtc ttacttcccc 60 tcg 6310961DNAArtificial SequenceCloning primer 109 gcgccaagct tattagcgca gttcccacca cttcaggtct cggtactgac atcgctcccc 60 g 6111022DNAArtificial SequenceCloning primer 110 tcattcacat tgagcgtcac cg 2211124DNAArtificial SequenceCloning primer 111 ttatattgac agcgcacaga gcgg 24112101DNAArtificial SequenceCloning primer 112 gcaagaattc accatgaact tggggaatcg actgtttatt ctgatagcgg tcttacttcc 60 cctcgcagta ttactgctct cattcacatt gagcgtcacc g 10111347DNAArtificial SequenceCloning primer 113 cgcggttacg taagcaactg cagttatatt gacagcgcac agagcgg 4711424DNAArtificial SequenceCloning primer 114 gtcacggccg agacttatag tcgc 2411523DNAArtificial SequenceCloning primer 115 ggtgtccggg cttttgtcac agg 2311637DNAArtificial SequenceCloning primer 116 cgcggctgca gatgtcacgg ccgagactta tagtcgc 3711738DNAArtificial SequenceCloning primer 117 cgcggtctag attctggtgt ccgggctttt gtcacagg 3811823DNAArtificial SequenceCloning primer 118 cagccccaga gcggctttca tgg 2311937DNAArtificial SequenceCloning primer 119 cgcggtctag atttcagccc cagagcggct ttcatgg 37120106DNAArtificial SequenceCloning primer 120 cgcggctgca gatgaaaata aaaacaggtg cacgcatcct cgcattatcc gcattaacga 60 cgatgatgtt ttccgcctcg gctctcgcca aaatctctag acgcgg 106121106DNAArtificial SequenceCloning primer 121 ccgcgtctag agattttggc gagagccgag gcggaaaaca tcatcgtcgt taatgcggat 60 aatgcgagga tgcgtgcacc tgtttttatt ttcatctgca gccgcg 10612226DNAArtificial SequenceCloning primer 122 ggtgcacgca tcctcgcatt atccgc 2612326DNAArtificial SequenceCloning primer 123 cggcatacca gaaagcggac atctgc 2612452DNAArtificial SequenceCloning primer 124 cgcggctgca gatgaaaata aaaacaggtg cacgcatcct cgcattatcc gc 5212542DNAArtificial SequenceCloning primer 125 cgcggtctag aacgcacggc ataccagaaa gcggacatct gc 4212627DNAArtificial SequenceCloning primer 126 cgcgacagcg cgcaataacc gttctcg 2712727DNAArtificial SequenceCloning primer 127 gctggttcat cagctcgttg aaagtgg 2712841DNAArtificial SequenceCloning primer 128 gcgccggcgc catacgcgac agcgcgcaat aaccgttctc g 4112952DNAArtificial SequenceCloning primer 129 ggcgctctag attattatta cgcctgctgg ttcatcagct cgttgaaagt gg 5213029DNAArtificial SequenceCloning primer 130 ggtagcacaa tcagattcgc ttatgacgg 2913125DNAArtificial SequenceCloning primer 131 gccgcccatg ccacccatgc cgccc 2513238DNAArtificial SequenceCloning primer 132 gcgtctagag gtagcacaat cagattcgct tatgacgg 3813349DNAArtificial SequenceCloning primer 133 ggcgcaagct tattattaca tcatgccgcc catgccaccc atgccgccc 4913427DNAArtificial SequenceCloning primer 134 gcgataaaat tattcacctg actgacg 2713526DNAArtificial SequenceCloning primer 135 gcgtcgagga actctttcaa ctgacc 2613666DNAArtificial SequenceCloning primer 136 cgcggctgca gatgatcgaa gcccgctcta gactcgagag cgataaaatt attcacctga 60 ctgacg 66137101DNAArtificial SequenceCloning primer 137 ccgcgggatc cttattaatc atcatgatct ttataatcgc catcatgatc tttataatcc 60 tcgagcgcca ggttagcgtc gaggaactct ttcaactgac c 10113865DNAArtificial SequenceCloning primer 138 tatgtaagga ggttgtcgac cggctcagtc tagaggtacc cgccctcatc cgaaagggcg 60 tattg 6513967DNAArtificial SequenceCloning primer 139 gatccaatac gccctttcgg atgagggcgg gtacctctag actgagccgg tcgacaacct 60 ccttaca 6714065DNAArtificial SequenceCloning primer 140 tatgtaagga ggttctgcag cggctcagtc tagaggtacc cgccctcatc cgaaagggcg 60 tattg 6514167DNAArtificial SequenceCloning primer 141 gatccaatac gccctttcgg atgagggcgg gtacctctag actgagccgc tgcagaacct 60 ccttaca 6714266DNAArtificial SequenceCloning primer 142 gatcctaagg aggttgtcga ccggctcagt ctagaggtac ccgccctcat ccgaaagggc 60 gtattc 6614366DNAArtificial SequenceCloning primer 143 tcgagaatac gccctttcgg atgagggcgg gtacctctag actgagccgg tcgacaacct 60 ccttag 6614466DNAArtificial SequenceCloning primer 144 gatcctaagg aggttctgca gcggctcagt ctagaggtac ccgccctcat ccgaaagggc 60 gtattc 6614566DNAArtificial SequenceCloning primer 145 tcgagaatac gccctttcgg atgagggcgg gtacctctag actgagccgc tgcagaacct 60 ccttag 661464740DNAArtificial SequenceExpression vector 146 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttaattaa tctttctgcg 420 aattgagatg acgccactgg ctgggcgtca tcccggtttc ccgggtaaac accaccgaaa 480 aatagttact atcttcaaag ccacattcgg tcgaaatatc actgattaac aggcggctat 540 gctggagaag atattgcgca tgacacactc tgacctgtcg cagatattga ttgatggtca 600 ttccagtctg ctggcgaaat tgctgacgca aaacgcgctc actgcacgat gcctcatcac 660 aaaatttatc cagcgcaaag ggacttttca ggctagccgc cagccgggta atcagcttat 720 ccagcaacgt ttcgctggat gttggcggca acgaatcact ggtgtaacga tggcgattca 780 gcaacatcac caactgcccg aacagcaact cagccatttc gttagcaaac ggcacatgct 840 gactactttc atgctcaagc tgaccgataa cctgccgcgc ctgcgccatc cccatgctac 900 ctaagcgcca gtgtggttgc cctgcgctgg cgttaaatcc cggaatcgcc ccctgccagt 960 caagattcag cttcagacgc tccgggcaat aaataatatt ctgcaaaacc agatcgttaa 1020 cggaagcgta ggagtgttta tcgtcagcat gaatgtaaaa gagatcgcca cgggtaatgc 1080 gataagggcg atcgttgagt acatgcaggc cattaccgcg ccagacaatc accagctcac 1140 aaaaatcatg tgtatgttca gcaaagacat cttgcggata acggtcagcc acagcgactg 1200 cctgctggtc gctggcaaaa aaatcatctt tgagaagttt taactgatgc gccaccgtgg 1260 ctacctcggc cagagaacga agttgattat tcgcaatatg gcgtacaaat acgttgagaa 1320 gattcgcgtt attgcagaaa gccatcccgt ccctggcgaa tatcacgcgg tgaccagtta 1380 aactctcggc gaaaaagcgt cgaaaagtgg ttactgtcgc tgaatccaca gcgataggcg 1440 atgtcagtaa cgctggcctc gctgtggcgt agcagatgtc gggctttcat cagtcgcagg 1500 cggttcaggt atcgctgagg cgtcagtccc gtttgctgct taagctgccg atgtagcgta 1560 cgcagtgaaa gagaaaattg atccgccacg gcatcccaat tcacctcatc ggcaaaatgg 1620 tcctccagcc aggccagaag caagttgaga cgtgatgcgc tgttttccag gttctcctgc 1680 aaactgcttt tacgcagcaa gagcagtaat tgcataaaca agatctcgcg actggcggtc 1740 gagggtaaat cattttcccc ttcctgctgt tccatctgtg caaccagctg tcgcacctgc 1800 tgcaatacgc tgtggttaac gcgccagtga gacggatact gcccatccag ctcttgtggc 1860 agcaactgat tcagcccggc gagaaactga aatcgatccg gcgagcgata cagcacattg 1920 gtcagacaca gattatcggt atgttcatac agatgccgat catgatcgcg tacgaaacag 1980 accgtgccac cggtgatggt atagggctgc ccattaaaca catgaatacc cgtgccatgt 2040 tcgacaatca caatttcatg aaaatcatga tgatgttcag gaaaatccgc ctgcgggagc 2100 cggggttcta tcgccacgga cgcgttacca gacggaaaaa aatccacact atgtaatacg 2160 gtcatactgg cctcctgatg tcgtcaacac ggcgaaatag taatcacgag gtcaggttct 2220 taccttaaat tttcgacgga aaaccacgta aaaaacgtcg atttttcaag atacagcgtg 2280 aattttcagg aaatgcggtg agcatcacat caccacaatt cagcaaattg tgaacatcat 2340 cacgttcatc tttccctggt tgccaatggc ccattttcct gtcagtaacg agaaggtcgc 2400 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttgtcg actctagagg 2460 atccccgcgc cctcatccga aagggcgtat tggtaccgag ctcgaattcg taatcatggt 2520 catagctgtt tcctgtgtga aattgttatc cgctcacaat tccacacaac atacgagccg 2580 gaagcataaa gtgtaaagcc tggggtgcct aatgagtgag ctaactcaca ttaattgcgt 2640 tgcgctcact gcccgctttc cagtcgggaa acctgtcgtg ccagctgcat taatgaatcg 2700 gccaacgcgc ggggagaggc ggtttgcgta ttgggcgctc ttccgcttcc tcgctcactg 2760 actcgctgcg ctcggtcgtt cggctgcggc gagcggtatc agctcactca aaggcggtaa 2820 tacggttatc cacagaatca ggggataacg caggaaagaa catgtgagca aaaggccagc 2880 aaaaggccag gaaccgtaaa aaggccgcgt tgctggcgtt tttccatagg ctccgccccc 2940 ctgacgagca tcacaaaaat cgacgctcaa gtcagaggtg gcgaaacccg acaggactat 3000 aaagatacca ggcgtttccc cctggaagct ccctcgtgcg ctctcctgtt ccgaccctgc 3060 cgcttaccgg atacctgtcc gcctttctcc cttcgggaag cgtggcgctt tctcatagct 3120 cacgctgtag gtatctcagt tcggtgtagg tcgttcgctc caagctgggc tgtgtgcacg 3180 aaccccccgt tcagcccgac cgctgcgcct tatccggtaa ctatcgtctt gagtccaacc 3240 cggtaagaca cgacttatcg ccactggcag cagccactgg taacaggatt agcagagcga 3300 ggtatgtagg cggtgctaca gagttcttga agtggtggcc taactacggc tacactagaa 3360 ggacagtatt tggtatctgc gctctgctga agccagttac cttcggaaaa agagttggta 3420 gctcttgatc cggcaaacaa accaccgctg gtagcggtgg tttttttgtt tgcaagcagc 3480 agattacgcg cagaaaaaaa ggatctcaag aagatccttt gatcttttct acggggtctg 3540 acgctcagtg gaacgaaaac tcacgttaag ggattttggt catgagatta tcaaaaagga 3600 tcttcaccta gatcctttta aattaaaaat gaagttttaa atcaatctaa agtatatatg 3660 agtaaacttg gtctgacagt taccaatgct taatcagtga ggcacctatc tcagcgatct 3720 gtctatttcg ttcatccata gttgcctgac tccccgtcgt gtagataact acgatacggg 3780 agggcttacc atctggcccc agtgctgcaa tgataccgcg agacccacgc tcaccggctc 3840 cagatttatc agcaataaac cagccagccg gaagggccga gcgcagaagt ggtcctgcaa 3900 ctttatccgc ctccatccag tctattaatt gttgccggga agctagagta agtagttcgc 3960 cagttaatag tttgcgcaac gttgttgcca ttgctacagg catcgtggtg tcacgctcgt 4020 cgtttggtat ggcttcattc agctccggtt cccaacgatc aaggcgagtt acatgatccc 4080 ccatgttgtg caaaaaagcg gttagctcct tcggtcctcc gatcgttgtc agaagtaagt 4140 tggccgcagt gttatcactc atggttatgg cagcactgca taattctctt actgtcatgc 4200 catccgtaag atgcttttct gtgactggtg agtactcaac caagtcattc tgagaatagt 4260 gtatgcggcg accgagttgc tcttgcccgg cgtcaatacg ggataatacc gcgccacata 4320 gcagaacttt aaaagtgctc atcattggaa aacgttcttc ggggcgaaaa ctctcaagga 4380 tcttaccgct gttgagatcc agttcgatgt aacccactcg tgcacccaac tgatcttcag 4440 catcttttac tttcaccagc gtttctgggt gagcaaaaac aggaaggcaa aatgccgcaa 4500 aaaagggaat aagggcgaca cggaaatgtt gaatactcat actcttcctt tttcaatatt 4560 attgaagcat ttatcagggt tattgtctca tgagcggata catatttgaa tgtatttaga 4620 aaaataaaca aataggggtt ccgcgcacat ttccccgaaa agtgccacct gacgtctaag 4680 aaaccattat tatcatgaca ttaacctata aaaataggcg tatcacgagg ccctttcgtc 47401474746DNAArtificial SequenceExpression vector 147 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttaattaa tctttctgcg 420 aattgagatg acgccactgg ctgggcgtca tcccggtttc ccgggtaaac accaccgaaa 480 aatagttact atcttcaaag ccacattcgg tcgaaatatc actgattaac aggcggctat 540 gctggagaag atattgcgca tgacacactc tgacctgtcg cagatattga ttgatggtca 600 ttccagtctg ctggcgaaat tgctgacgca aaacgcgctc actgcacgat gcctcatcac 660 aaaatttatc cagcgcaaag ggacttttca ggctagccgc cagccgggta atcagcttat 720 ccagcaacgt ttcgctggat gttggcggca acgaatcact ggtgtaacga tggcgattca 780 gcaacatcac caactgcccg aacagcaact cagccatttc gttagcaaac ggcacatgct 840 gactactttc atgctcaagc tgaccgataa cctgccgcgc ctgcgccatc cccatgctac 900 ctaagcgcca gtgtggttgc cctgcgctgg cgttaaatcc cggaatcgcc ccctgccagt 960 caagattcag cttcagacgc tccgggcaat aaataatatt ctgcaaaacc agatcgttaa 1020 cggaagcgta ggagtgttta tcgtcagcat gaatgtaaaa gagatcgcca cgggtaatgc 1080 gataagggcg atcgttgagt acatgcaggc cattaccgcg ccagacaatc accagctcac 1140 aaaaatcatg tgtatgttca gcaaagacat cttgcggata acggtcagcc acagcgactg 1200 cctgctggtc gctggcaaaa aaatcatctt tgagaagttt taactgatgc gccaccgtgg 1260 ctacctcggc cagagaacga agttgattat tcgcaatatg gcgtacaaat acgttgagaa 1320 gattcgcgtt attgcagaaa gccatcccgt ccctggcgaa tatcacgcgg tgaccagtta 1380 aactctcggc gaaaaagcgt cgaaaagtgg ttactgtcgc tgaatccaca gcgataggcg 1440 atgtcagtaa cgctggcctc gctgtggcgt agcagatgtc gggctttcat cagtcgcagg 1500 cggttcaggt atcgctgagg cgtcagtccc gtttgctgct taagctgccg atgtagcgta 1560 cgcagtgaaa gagaaaattg atccgccacg gcatcccaat tcacctcatc ggcaaaatgg 1620 tcctccagcc aggccagaag caagttgaga cgtgatgcgc tgttttccag gttctcctgc 1680 aaactgcttt tacgcagcaa gagcagtaat tgcataaaca agatctcgcg actggcggtc 1740 gagggtaaat cattttcccc ttcctgctgt tccatctgtg caaccagctg tcgcacctgc 1800 tgcaatacgc tgtggttaac gcgccagtga gacggatact gcccatccag ctcttgtggc 1860 agcaactgat tcagcccggc gagaaactga aatcgatccg gcgagcgata cagcacattg 1920 gtcagacaca gattatcggt atgttcatac agatgccgat catgatcgcg tacgaaacag 1980 accgtgccac cggtgatggt atagggctgc ccattaaaca catgaatacc cgtgccatgt 2040 tcgacaatca caatttcatg aaaatcatga tgatgttcag gaaaatccgc ctgcgggagc 2100 cggggttcta tcgccacgga cgcgttacca gacggaaaaa aatccacact atgtaatacg 2160 gtcatactgg cctcctgatg tcgtcaacac ggcgaaatag taatcacgag gtcaggttct 2220 taccttaaat tttcgacgga aaaccacgta aaaaacgtcg atttttcaag atacagcgtg 2280 aattttcagg aaatgcggtg agcatcacat caccacaatt cagcaaattg tgaacatcat 2340 cacgttcatc tttccctggt tgccaatggc ccattttcct gtcagtaacg agaaggtcgc 2400 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc aggtcgactc 2460 tagaggatcc ccgcgccctc atccgaaagg gcgtattggt accgagctcg aattcgtaat 2520 catggtcata gctgtttcct gtgtgaaatt gttatccgct cacaattcca cacaacatac 2580 gagccggaag cataaagtgt aaagcctggg gtgcctaatg agtgagctaa ctcacattaa 2640 ttgcgttgcg ctcactgccc gctttccagt cgggaaacct gtcgtgccag ctgcattaat 2700 gaatcggcca acgcgcgggg agaggcggtt tgcgtattgg gcgctcttcc gcttcctcgc 2760 tcactgactc gctgcgctcg gtcgttcggc tgcggcgagc ggtatcagct cactcaaagg 2820 cggtaatacg gttatccaca gaatcagggg ataacgcagg aaagaacatg tgagcaaaag 2880 gccagcaaaa ggccaggaac cgtaaaaagg ccgcgttgct ggcgtttttc cataggctcc 2940 gcccccctga cgagcatcac aaaaatcgac gctcaagtca gaggtggcga aacccgacag 3000 gactataaag ataccaggcg tttccccctg gaagctccct cgtgcgctct cctgttccga 3060 ccctgccgct taccggatac ctgtccgcct ttctcccttc gggaagcgtg gcgctttctc 3120 atagctcacg ctgtaggtat ctcagttcgg tgtaggtcgt tcgctccaag ctgggctgtg 3180 tgcacgaacc ccccgttcag cccgaccgct gcgccttatc cggtaactat cgtcttgagt 3240 ccaacccggt aagacacgac ttatcgccac tggcagcagc cactggtaac aggattagca 3300 gagcgaggta tgtaggcggt gctacagagt tcttgaagtg gtggcctaac tacggctaca 3360 ctagaaggac agtatttggt atctgcgctc tgctgaagcc agttaccttc ggaaaaagag 3420 ttggtagctc ttgatccggc aaacaaacca ccgctggtag cggtggtttt tttgtttgca 3480 agcagcagat tacgcgcaga aaaaaaggat ctcaagaaga tcctttgatc ttttctacgg 3540 ggtctgacgc tcagtggaac gaaaactcac gttaagggat tttggtcatg agattatcaa 3600 aaaggatctt cacctagatc cttttaaatt aaaaatgaag ttttaaatca atctaaagta 3660 tatatgagta aacttggtct gacagttacc aatgcttaat cagtgaggca cctatctcag 3720 cgatctgtct atttcgttca tccatagttg cctgactccc cgtcgtgtag ataactacga 3780 tacgggaggg cttaccatct ggccccagtg ctgcaatgat accgcgagac ccacgctcac 3840 cggctccaga tttatcagca ataaaccagc cagccggaag ggccgagcgc agaagtggtc 3900 ctgcaacttt atccgcctcc atccagtcta ttaattgttg ccgggaagct agagtaagta 3960 gttcgccagt taatagtttg cgcaacgttg ttgccattgc tacaggcatc gtggtgtcac 4020 gctcgtcgtt tggtatggct tcattcagct ccggttccca acgatcaagg cgagttacat 4080 gatcccccat gttgtgcaaa aaagcggtta gctccttcgg tcctccgatc gttgtcagaa 4140 gtaagttggc cgcagtgtta tcactcatgg ttatggcagc actgcataat tctcttactg 4200 tcatgccatc cgtaagatgc ttttctgtga ctggtgagta ctcaaccaag tcattctgag 4260 aatagtgtat gcggcgaccg agttgctctt gcccggcgtc aatacgggat aataccgcgc 4320 cacatagcag aactttaaaa gtgctcatca ttggaaaacg ttcttcgggg cgaaaactct 4380 caaggatctt accgctgttg agatccagtt cgatgtaacc cactcgtgca cccaactgat 4440 cttcagcatc ttttactttc accagcgttt ctgggtgagc aaaaacagga aggcaaaatg 4500 ccgcaaaaaa gggaataagg gcgacacgga aatgttgaat actcatactc ttcctttttc 4560 aatattattg aagcatttat cagggttatt gtctcatgag cggatacata tttgaatgta 4620 tttagaaaaa taaacaaata ggggttccgc gcacatttcc ccgaaaagtg ccacctgacg 4680 tctaagaaac cattattatc atgacattaa cctataaaaa taggcgtatc acgaggccct 4740 ttcgtc 47461483946DNAArtificial SequenceExpression vector 148 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttcaagcc gtcaattgtc 420 tgattcgtta ccaattatga caacttgacg gctacatcat tcactttttc ttcacaaccg 480 gcacggaact cgctcgggct ggccccggtg cattttttaa atacccgcga gaaatagagt 540 tgatcgtcaa aaccaacatt gcgaccgacg gtggcgatag gcatccgggt ggtgctcaaa 600 agcagcttcg cctggctgat acgttggtcc tcgcgccagc ttaagacgct aatccctaac 660 tgctggcgga aaagatgtga cagacgcgac ggcgacaagc aaacatgctg tgcgacgctg 720 gcgatatcaa aattgctgtc tgccaggtga tcgctgatgt actgacaagc ctcgcgtacc 780 cgattatcca tcggtggatg gagcgactcg ttaatcgctt ccatgcgccg cagtaacaat 840 tgctcaagca gatttatcgc cagcagctcc gaatagcgcc cttccccttg cccggcgtta 900 atgatttgcc caaacaggtc gctgaaatgc ggctggtgcg cttcatccgg gcgaaagaac 960 cccgtattgg caaatattga cggccagtta agccattcat gccagtaggc gcgcggacga 1020 aagtaaaccc actggtgata ccattcgcga gcctccggat gacgaccgta gtgatgaatc 1080 tctcctggcg ggaacagcaa aatatcaccc ggtcggcaaa caaattctcg tccctgattt 1140 ttcaccaccc cctgaccgcg aatggtgaga ttgagaatat aacctttcat tcccagcggt 1200 cggtcgataa aaaaatcgag ataaccgttg gcctcaatcg gcgttaaacc cgccaccaga 1260 tgggcattaa acgagtatcc cggcagcagg ggatcatttt gcgcttcagc catacttttc 1320 atactcccgc cattcagaga agaaaccaat tgtccatatt gcatcagaca ttgccgtcac 1380 tgcgtctttt actggctctt ctcgctaacc aaaccggtaa ccccgcttat taaaagcatt 1440 ctgtaacaaa gcgggaccaa agccatgaca aaaacgcgta acaaaagtgt ctataatcac 1500 ggcagaaaag tccacattga ttatttgcac ggcgtcacac tttgctatgc catagcattt 1560 ttatccataa gattagcgga tcctacctga cgctttttat cgcaactctc tactgtttct 1620 ccatacccgt ttttttgggc tagcaggagg ccgtcgactc tagaggatcc ccgcgccctc 1680 atccgaaagg gcgtattggt accgagctcg aattcgtaat catggtcata gctgtttcct 1740 gtgtgaaatt gttatccgct cacaattcca cacaacatac gagccggaag cataaagtgt 1800 aaagcctggg gtgcctaatg agtgagctaa ctcacattaa ttgcgttgcg ctcactgccc 1860 gctttccagt cgggaaacct gtcgtgccag ctgcattaat gaatcggcca acgcgcgggg 1920 agaggcggtt tgcgtattgg gcgctcttcc gcttcctcgc tcactgactc gctgcgctcg 1980 gtcgttcggc tgcggcgagc ggtatcagct cactcaaagg cggtaatacg gttatccaca 2040 gaatcagggg ataacgcagg aaagaacatg tgagcaaaag gccagcaaaa ggccaggaac 2100 cgtaaaaagg ccgcgttgct ggcgtttttc cataggctcc gcccccctga cgagcatcac 2160 aaaaatcgac gctcaagtca gaggtggcga aacccgacag gactataaag ataccaggcg 2220 tttccccctg gaagctccct cgtgcgctct cctgttccga ccctgccgct taccggatac 2280 ctgtccgcct ttctcccttc gggaagcgtg gcgctttctc atagctcacg ctgtaggtat 2340 ctcagttcgg tgtaggtcgt tcgctccaag ctgggctgtg tgcacgaacc ccccgttcag 2400 cccgaccgct gcgccttatc cggtaactat cgtcttgagt ccaacccggt aagacacgac 2460 ttatcgccac tggcagcagc cactggtaac aggattagca gagcgaggta tgtaggcggt 2520 gctacagagt tcttgaagtg gtggcctaac tacggctaca ctagaaggac agtatttggt 2580 atctgcgctc tgctgaagcc agttaccttc ggaaaaagag ttggtagctc ttgatccggc 2640 aaacaaacca ccgctggtag cggtggtttt tttgtttgca agcagcagat tacgcgcaga 2700 aaaaaaggat ctcaagaaga tcctttgatc ttttctacgg ggtctgacgc tcagtggaac 2760 gaaaactcac gttaagggat tttggtcatg agattatcaa aaaggatctt cacctagatc 2820 cttttaaatt aaaaatgaag ttttaaatca atctaaagta tatatgagta aacttggtct 2880 gacagttacc aatgcttaat cagtgaggca cctatctcag cgatctgtct atttcgttca 2940 tccatagttg cctgactccc cgtcgtgtag ataactacga tacgggaggg cttaccatct 3000 ggccccagtg ctgcaatgat accgcgagac ccacgctcac cggctccaga tttatcagca 3060 ataaaccagc cagccggaag ggccgagcgc agaagtggtc ctgcaacttt atccgcctcc 3120 atccagtcta ttaattgttg ccgggaagct agagtaagta gttcgccagt taatagtttg 3180 cgcaacgttg ttgccattgc tacaggcatc gtggtgtcac gctcgtcgtt tggtatggct 3240 tcattcagct ccggttccca acgatcaagg cgagttacat gatcccccat gttgtgcaaa 3300 aaagcggtta gctccttcgg tcctccgatc gttgtcagaa gtaagttggc cgcagtgtta 3360 tcactcatgg ttatggcagc actgcataat tctcttactg tcatgccatc cgtaagatgc 3420 ttttctgtga ctggtgagta ctcaaccaag tcattctgag aatagtgtat gcggcgaccg 3480 agttgctctt gcccggcgtc aatacgggat aataccgcgc cacatagcag aactttaaaa 3540 gtgctcatca ttggaaaacg ttcttcgggg cgaaaactct caaggatctt accgctgttg 3600 agatccagtt cgatgtaacc cactcgtgca cccaactgat cttcagcatc ttttactttc 3660 accagcgttt ctgggtgagc aaaaacagga aggcaaaatg ccgcaaaaaa gggaataagg 3720 gcgacacgga aatgttgaat actcatactc ttcctttttc aatattattg aagcatttat 3780 cagggttatt gtctcatgag cggatacata tttgaatgta tttagaaaaa taaacaaata 3840 ggggttccgc gcacatttcc ccgaaaagtg ccacctgacg tctaagaaac cattattatc 3900 atgacattaa cctataaaaa taggcgtatc acgaggccct ttcgtc 39461493952DNAArtificial SequenceExpression vector 149 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttcaagcc gtcaattgtc 420 tgattcgtta ccaattatga caacttgacg gctacatcat tcactttttc ttcacaaccg 480 gcacggaact cgctcgggct ggccccggtg cattttttaa atacccgcga gaaatagagt 540 tgatcgtcaa aaccaacatt gcgaccgacg gtggcgatag gcatccgggt ggtgctcaaa 600 agcagcttcg cctggctgat acgttggtcc tcgcgccagc ttaagacgct aatccctaac 660 tgctggcgga aaagatgtga cagacgcgac ggcgacaagc aaacatgctg tgcgacgctg 720 gcgatatcaa aattgctgtc tgccaggtga tcgctgatgt actgacaagc ctcgcgtacc 780 cgattatcca tcggtggatg gagcgactcg ttaatcgctt ccatgcgccg cagtaacaat 840 tgctcaagca gatttatcgc cagcagctcc gaatagcgcc cttccccttg cccggcgtta 900 atgatttgcc caaacaggtc gctgaaatgc ggctggtgcg cttcatccgg gcgaaagaac 960 cccgtattgg caaatattga cggccagtta agccattcat gccagtaggc gcgcggacga 1020 aagtaaaccc actggtgata ccattcgcga gcctccggat gacgaccgta gtgatgaatc 1080 tctcctggcg ggaacagcaa aatatcaccc ggtcggcaaa caaattctcg tccctgattt 1140 ttcaccaccc cctgaccgcg aatggtgaga ttgagaatat aacctttcat tcccagcggt 1200 cggtcgataa aaaaatcgag ataaccgttg gcctcaatcg gcgttaaacc cgccaccaga 1260 tgggcattaa acgagtatcc cggcagcagg ggatcatttt gcgcttcagc catacttttc 1320 atactcccgc cattcagaga agaaaccaat tgtccatatt gcatcagaca ttgccgtcac 1380 tgcgtctttt actggctctt ctcgctaacc aaaccggtaa ccccgcttat taaaagcatt 1440 ctgtaacaaa gcgggaccaa agccatgaca aaaacgcgta acaaaagtgt ctataatcac 1500 ggcagaaaag tccacattga ttatttgcac ggcgtcacac tttgctatgc catagcattt 1560 ttatccataa gattagcgga tcctacctga cgctttttat cgcaactctc tactgtttct 1620 ccatacccgt ttttttgggc tagcaggagg ccctgcaggt cgactctaga ggatccccgc 1680 gccctcatcc gaaagggcgt attggtaccg agctcgaatt cgtaatcatg gtcatagctg 1740 tttcctgtgt gaaattgtta tccgctcaca attccacaca acatacgagc cggaagcata 1800 aagtgtaaag cctggggtgc ctaatgagtg agctaactca cattaattgc gttgcgctca 1860 ctgcccgctt tccagtcggg aaacctgtcg tgccagctgc attaatgaat cggccaacgc 1920 gcggggagag gcggtttgcg tattgggcgc tcttccgctt cctcgctcac tgactcgctg 1980 cgctcggtcg ttcggctgcg gcgagcggta tcagctcact caaaggcggt aatacggtta 2040 tccacagaat caggggataa cgcaggaaag aacatgtgag caaaaggcca gcaaaaggcc 2100 aggaaccgta aaaaggccgc gttgctggcg tttttccata ggctccgccc ccctgacgag 2160 catcacaaaa atcgacgctc aagtcagagg tggcgaaacc cgacaggact ataaagatac 2220 caggcgtttc cccctggaag ctccctcgtg cgctctcctg ttccgaccct gccgcttacc 2280 ggatacctgt ccgcctttct cccttcggga agcgtggcgc tttctcatag ctcacgctgt 2340 aggtatctca gttcggtgta ggtcgttcgc tccaagctgg gctgtgtgca cgaacccccc 2400 gttcagcccg accgctgcgc cttatccggt aactatcgtc ttgagtccaa cccggtaaga 2460 cacgacttat cgccactggc agcagccact ggtaacagga ttagcagagc gaggtatgta 2520 ggcggtgcta cagagttctt gaagtggtgg cctaactacg gctacactag aaggacagta 2580 tttggtatct gcgctctgct gaagccagtt accttcggaa aaagagttgg tagctcttga 2640 tccggcaaac aaaccaccgc tggtagcggt ggtttttttg tttgcaagca gcagattacg 2700 cgcagaaaaa aaggatctca agaagatcct ttgatctttt ctacggggtc tgacgctcag 2760 tggaacgaaa actcacgtta agggattttg gtcatgagat tatcaaaaag gatcttcacc 2820 tagatccttt taaattaaaa atgaagtttt aaatcaatct aaagtatata tgagtaaact 2880 tggtctgaca gttaccaatg cttaatcagt gaggcaccta tctcagcgat ctgtctattt 2940 cgttcatcca tagttgcctg actccccgtc gtgtagataa ctacgatacg ggagggctta 3000 ccatctggcc ccagtgctgc aatgataccg cgagacccac gctcaccggc tccagattta 3060 tcagcaataa accagccagc cggaagggcc gagcgcagaa gtggtcctgc aactttatcc 3120 gcctccatcc agtctattaa ttgttgccgg gaagctagag taagtagttc gccagttaat 3180 agtttgcgca acgttgttgc cattgctaca ggcatcgtgg tgtcacgctc gtcgtttggt 3240 atggcttcat tcagctccgg ttcccaacga tcaaggcgag ttacatgatc ccccatgttg 3300 tgcaaaaaag cggttagctc cttcggtcct ccgatcgttg tcagaagtaa gttggccgca 3360 gtgttatcac tcatggttat ggcagcactg cataattctc ttactgtcat gccatccgta 3420 agatgctttt ctgtgactgg tgagtactca accaagtcat tctgagaata gtgtatgcgg 3480 cgaccgagtt gctcttgccc ggcgtcaata cgggataata ccgcgccaca tagcagaact 3540 ttaaaagtgc tcatcattgg aaaacgttct tcggggcgaa aactctcaag gatcttaccg 3600 ctgttgagat ccagttcgat gtaacccact cgtgcaccca actgatcttc agcatctttt 3660 actttcacca gcgtttctgg gtgagcaaaa acaggaaggc aaaatgccgc aaaaaaggga 3720 ataagggcga cacggaaatg ttgaatactc atactcttcc tttttcaata ttattgaagc 3780 atttatcagg gttattgtct catgagcgga tacatatttg aatgtattta gaaaaataaa 3840 caaatagggg ttccgcgcac atttccccga aaagtgccac ctgacgtcta agaaaccatt 3900 attatcatga cattaaccta taaaaatagg cgtatcacga ggccctttcg tc 39521503886DNAArtificial SequenceExpression vector 150 tcgcgcgttt cggtgatgac ggtgaaaacc tctgacacat gcagctcccg gagacggtca 60 cagcttgtct gtaagcggat gccgggagca gacaagcccg tcagggcgcg tcagcgggtg 120 ttggcgggtg tcggggctgg cttaactatg cggcatcaga gcagattgta ctgagagtgc 180 accatatgcg gtgtgaaata ccgcacagat gcgtaaggag aaaataccgc atcaggcgcc 240 attcgccatt caggctgcgc aactgttggg aagggcgatc ggtgcgggcc tcttcgctat 300 tacgccagct ggcgaaaggg ggatgtgctg caaggcgatt aagttgggta acgccagggt 360 tttcccagtc acgacgttgt aaaacgacgg ccagtgccaa gcttttagcc gggaaacgtc 420 tggcggcgct gttggctaag tttgcggtat tgttgcggcg acatgccgac atatttgccg 480 aacgtgctgt aaaaacgact acttgaacga aagcctgccg tcagggcaat atcgagaata 540 cttttatcgg tatcgctcag taacgcgcga acgtggttga tgcgcatcgc ggtaatgtac 600 tgtttcatcg tcaattgcat gacccgctgg aatatcccca ttgcatagtt ggcgttaagt 660 ttgacgtgct cagccacatc gttgatggtc agcgcctgat catagttttc ggcaataaag 720 cccagcatct ggctaacata aaattgcgca tggcgcgaga cgctgttttt gtgtgtgcgc 780 gaggttttat tgaccagaat cggttcccag ccagagaggc taaatcgctt gagcatcagg 840 ccaatttcat caatggcgag ctggcgaatt tgctcgttcg gactgtttaa ttcctgctgc 900 cagcggcgca cttcaaacgg gctaagttgc tgtgtggcca gtgatttgat caccatgccg 960 tgagtgacgt ggttaatcag gtctttatcc agcggccagg agagaaacag atgcatcggc 1020 agattaaaaa tcgccatgct ctgacaggtt ccggtatctg ttagttggtg cggtgtacag 1080 gcccagaaca gcgtgatatg accctgattg atattcactt tttcattgtt gatcaggtat 1140 tccacatcgc catcgaaagg cacattcact tcgacctgac catgccagtg gctggtgggc 1200 atgatatgcg gtgcgcgaaa ctcaatctcc atccgctggt attccgaata cagcgacagc 1260 gggctgcggg tctgtttttc gtcgctgctg cacataaacg tatctgtatt catggatggc 1320 tctctttcct ggaatatcag aattatggca ggagtgaggg aggatgactg cgagtgggag 1380 cacggttttc accctcttcc cagaggggcg aggggactct ccgagtatca tgaggccgaa 1440 aactctgctt ttcaggtaat ttattcccat aaactcagat ttactgctgc ttcacgcagg 1500 atctgagttt atgggaatgc tcaacctgga agccggaggt tttctgcaga ttcgcctgcc 1560 atgatgaagt tattcaagca agccaggagg tcgtcgactc tagaggatcc ccgcgccctc 1620 atccgaaagg gcgtattggt accgagctcg aattcgtaat catggtcata gctgtttcct 1680 gtgtgaaatt gttatccgct cacaattcca cacaacatac gagccggaag cataaagtgt 1740 aaagcctggg gtgcctaatg agtgagctaa ctcacattaa ttgcgttgcg ctcactgccc 1800 gctttccagt cgggaaacct gtcgtgccag ctgcattaat gaatcggcca acgcgcgggg 1860 agaggcggtt tgcgtattgg gcgctcttcc gcttcctcgc tcactgactc gctgcgctcg 1920 gtcgttcggc tgcggcgagc ggtatcagct cactcaaagg cggtaatacg gttatccaca 1980 gaatcagggg ataacgcagg aaagaacatg tgagcaaaag gccagcaaaa ggccaggaac 2040 cgtaaaaagg ccgcgttgct ggcgtttttc cataggctcc gcccccctga cgagcatcac 2100 aaaaatcgac gctcaagtca gaggtggcga aacccgacag gactataaag ataccaggcg 2160 tttccccctg gaagctccct cgtgcgctct cctgttccga ccctgccgct taccggatac 2220 ctgtccgcct ttctcccttc gggaagcgtg gcgctttctc atagctcacg ctgtaggtat 2280 ctcagttcgg tgtaggtcgt tcgctccaag ctgggctgtg tgcacgaacc ccccgttcag 2340 cccgaccgct gcgccttatc cggtaactat cgtcttgagt ccaacccggt aagacacgac 2400 ttatcgccac tggcagcagc cactggtaac aggattagca gagcgaggta tgtaggcggt 2460 gctacagagt tcttgaagtg gtggcctaac tacggctaca ctagaaggac agtatttggt 2520 atctgcgctc tgctgaagcc agttaccttc ggaaaaagag ttggtagctc ttgatccggc 2580 aaacaaacca ccgctggtag cggtggtttt tttgtttgca agcagcagat tacgcgcaga 2640 aaaaaaggat ctcaagaaga tcctttgatc ttttctacgg ggtctgacgc tcagtggaac 2700 gaaaactcac gttaagggat tttggtcatg agattatcaa aaaggatctt cacctagatc 2760 cttttaaatt aaaaatgaag ttttaaatca atctaaagta tatatgagta aacttggtct 2820 gacagttacc aatgcttaat cagtgaggca cctatctcag cgatctgtct atttcgttca 2880 tccatagttg cctgactccc cgtcgtgtag ataactacga tacgggaggg cttaccatct 2940 ggccccagtg ctgcaatgat accgcgagac ccacgctcac cggctccaga tttatcagca 3000 ataaaccagc cagccggaag ggccgagcgc agaagtggtc ctgcaacttt atccgcctcc 3060 atccagtcta ttaattgttg ccgggaagct agagtaagta gttcgccagt taatagtttg 3120 cgcaacgttg ttgccattgc tacaggcatc gtggtgtcac gctcgtcgtt tggtatggct 3180 tcattcagct ccggttccca acgatcaagg cgagttacat gatcccccat gttgtgcaaa 3240 aaagcggtta gctccttcgg tcctccgatc gttgtcagaa gtaagttggc cgcagtgtta 3300 tcactcatgg ttatggcagc actgcataat tctcttactg tcatgccatc cgtaagatgc 3360 ttttctgtga ctggtgagta ctcaaccaag tcattctgag aatagtgtat gcggcgaccg 3420 agttgctctt gcccggcgtc aatacgggat aataccgcgc cacatagcag aactttaaaa 3480 gtgctcatca ttggaaaacg ttcttcgggg cgaaaactct caaggatctt accgctgttg 3540 agatccagtt cgatgtaacc cactcgtgca cccaactgat cttcagcatc ttttactttc 3600 accagcgttt ctgggtgagc aaaaacagga aggcaaaatg ccgcaaaaaa gggaataagg 3660 gcgacacgga aatgttgaat actcatactc ttcctttttc aatattattg aagcatttat 3720 cagggttatt gtctcatgag cggatacata tttgaatgta tttagaaaaa taaacaaata 3780 ggggttccgc gcacatttcc ccgaaaagtg ccacctgacg tctaagaaac cattattatc 3840 atgacattaa cctataaaaa taggcgtatc acgaggccct ttcgtc 388615128DNAArtificial SequenceCloning primer 151 gcagaacctc ctgaatttca ttacgacc 2815286DNAArtificial SequenceCloning primer 152 ccgcgggtac caatacgccc tttcggatga gggcgcgggg atcctctaga gtcgacgtcg 60 acaacctcct gaatttcatt acgacc 8615386DNAArtificial SequenceCloning primer 153 ccgcgggtac caatacgccc tttcggatga gggcgcgggg atcctctaga gtcgacctgc 60 agaacctcct gaatttcatt acgacc 8615438DNAArtificial SequenceCloning primer 154 ctgcagggcc tcctgctagc ccaaaaaaac gggtatgg 3815594DNAArtificial SequenceCloning primer 155 ccgcgggtac caatacgccc tttcggatga gggcgcgggg atcctctaga gtcgacgtcg 60 acggcctcct gctagcccaa aaaaacgggt atgg 9415694DNAArtificial SequenceCloning primer 156 ccgcgggtac caatacgccc tttcggatga gggcgcgggg atcctctaga gtcgacctgc 60 agggcctcct gctagcccaa aaaaacgggt atgg 9415732DNAArtificial SequenceCloning primer 157 cctcctggct tgcttgaata acttcatcat gg 3215891DNAArtificial SequenceCloning primer 158 ccgcgggtac caatacgccc tttcggatga gggcgcgggg atcctctaga gtcgaccccc 60 tcctggcttg cttgaataac ttcatcatgg c 911592319DNAArtificial SequenceGene encoding a fusion protein 159 gtcgacatga aaataaaaac aggtgcacgc atcctcgcat tatccgcatt aacgacgatg 60 atgttttccg cctcggctct cgccaaaatc gaagaaggta aactggtaat ctggattaac 120 ggcgataaag gctataacgg tctcgctgaa gtcggtaaga aattcgagaa agataccgga 180 attaaagtca ccgttgagca tccggataaa ctggaagaga aattcccaca ggttgcggca 240 actggcgatg gccctgacat tatcttctgg gcacacgacc gctttggtgg ctacgctcaa 300 tctggcctgt tggctgaaat caccccggac aaagcgttcc aggacaagct gtatccgttt 360 acctgggatg ccgtacgtta caacggcaag ctgattgctt acccgatcgc tgttgaagcg 420 ttatcgctga tttataacaa agatctgctg ccgaacccgc caaaaacctg ggaagagatc 480 ccggcgctgg ataaagaact gaaagcgaaa ggtaagagcg cgctgatgtt caacctgcaa 540 gaaccgtact tcacctggcc gctgattgct gctgacgggg gttatgcgtt caagtatgaa 600 aacggcaagt acgacattaa agacgtgggc gtggataacg ctggcgcgaa agcgggtctg 660 accttcctgg ttgacctgat taaaaacaaa cacatgaatg cagacaccga ttactccatc 720 gcagaagctg cctttaataa aggcgaaaca gcgatgacca tcaacggccc gtgggcatgg 780 tccaacatcg acaccagcaa agtgaattat ggtgtaacgg tactgccgac cttcaagggt 840 caaccatcca aaccgttcgt tggcgtgctg agcgcaggta ttaacgccgc cagtccgaac 900 aaagagctgg cgaaagagtt cctcgaaaac tatctgctga ctgatgaagg tctggaagcg 960 gttaataaag acaaaccgct gggtgccgta gcgctgaagt cttacgagga agagttggcg 1020 aaagatccac gtattgccgc caccatggaa aacgcccaga aaggtgaaat catgccgaac 1080 atcccgcaga tgtccgcttt ctggtatgcc gtgctgatcg aagcccgcac ctcggaatcc 1140 gacacggcag ggcccaacag cgacctggac gtgaacactg acatttattc caaggtgctg 1200 gtgactgcta tatacctggc actcttcgtg gtgggcactg tgggcaactc cgtgacagcc 1260 ttcactctag cgcggaagaa gtcactgcag agcctgcaga gcactgtgca ttaccacctg 1320 ggcagcctgg cactgtcgga cctgcttatc cttctgctgg ccatgcccgt ggagctatac 1380 aacttcatct gggtacacca tccctgggcc tttggggacg ctggctgccg tggctactat 1440 ttcctgcgtg atgcctgcac ctatgccaca gccctcaatg tagccagcct gagtgtggag 1500 cgctacttgg ccatctgcca tcccttcaag gccaagaccc tcatgtcccg cagccgcacc 1560 aagaaattca tcagtgccat atggctagct tcggcgctgc tggctatacc catgcttttc 1620 accatgggcc tgcagaaccg cagtggtgac ggcacgcacc ctggcggcct ggtgtgcaca 1680 cccattgtgg acacagccac tgtcaaggtc gtcatccagg ttaacacctt catgtccttc 1740 ctgtttccca tgttggtcat ctccatccta aacaccgtga ttgccaacaa actgacagtc 1800 atggtgcacc aggccgccga gcagggccga gtgtgcaccg tgggcacaca caacggttta 1860 gagcacagca cgttcaacat gaccatcgag ccgggtcgtg tccaggccct gcgccacgga 1920 gtcctcgtct tacgtgctgt ggtcattgcc tttgtggtct gctggctgcc ctaccacgtg 1980 cgacgcctga tgttctgcta tatctcggat gaacagtgga ctacgttcct cttcgatttc 2040 taccactatt tctacatgct aaccaacgct ctcttctacg tcagctccgc catcaatccc 2100 atcctctaca acctggtctc cgccaacttc cgccaggtct ttctgtccac gctggcctgc 2160 ctttgtcctg ggtggcgcca ccgccgaaag aagaggccaa cgttctccag gaagcccaac 2220 agcatgtcca gcaaccatgc cttttccacc agcgccaccc gggagaccct gtacgcggcc 2280 gcagattata aagatgacga tgacaaataa taaggtacc 23191601293DNAArtificial SequenceGene encoding a fusion protein 160 gtcgacatga aaataaaaac aggtgcacgc atcctcgcat tatccgcatt aacgacgatg 60 atgttttccg cctcggctct cgccaaaatc atcgaagccc gcacctcgga atccgacacg 120 gcagggccca acagcgacct ggacgtgaac actgacattt attccaaggt gctggtgact 180 gctatatacc tggcactctt cgtggtgggc actgtgggca actccgtgac agccttcact 240 ctagcgcgga agaagtcact gcagagcctg cagagcactg tgcattacca cctgggcagc 300 ctggcactgt cggacctgct tatccttctg ctggccatgc ccgtggagct atacaacttc 360 atctgggtac accatccctg ggcctttggg gacgctggct gccgtggcta ctatttcctg 420 cgtgatgcct gcacctatgc cacagccctc aatgtagcca gcctgagtgt ggagcgctac 480 ttggccatct gccatccctt caaggccaag accctcatgt cccgcagccg caccaagaaa 540 ttcatcagtg ccatatggct agcttcggcg ctgctggcta tacccatgct tttcaccatg 600 ggcctgcaga accgcagtgg tgacggcacg caccctggcg gcctggtgtg cacacccatt 660 gtggacacag ccactgtcaa ggtcgtcatc caggttaaca ccttcatgtc cttcctgttt 720 cccatgttgg tcatctccat cctaaacacc gtgattgcca acaaactgac agtcatggtg 780 caccaggccg ccgagcaggg ccgagtgtgc accgtgggca cacacaacgg tttagagcac 840 agcacgttca acatgaccat cgagccgggt cgtgtccagg ccctgcgcca cggagtcctc 900 gtcttacgtg ctgtggtcat tgcctttgtg gtctgctggc tgccctacca cgtgcgacgc 960 ctgatgttct gctatatctc ggatgaacag tggactacgt tcctcttcga tttctaccac 1020 tatttctaca tgctaaccaa cgctctcttc tacgtcagct ccgccatcaa tcccatcctc 1080 tacaacctgg tctccgccaa cttccgccag gtctttctgt ccacgctggc ctgcctttgt 1140 cctgggtggc gccaccgccg aaagaagagg ccaacgttct ccaggaagcc caacagcatg 1200 tccagcaacc atgccttttc caccagcgcc acccgggaga ccctgtacgc ggccgcagat 1260 tataaagatg acgatgacaa ataataaggt acc 12931612652DNAArtificial SequenceGene encoding a fusion protein 161 gtcgacatga aaataaaaac aggtgcacgc atcctcgcat tatccgcatt aacgacgatg 60 atgttttccg cctcggctct cgccaaaatc gaagaaggta aactggtaat ctggattaac 120 ggcgataaag gctataacgg tctcgctgaa gtcggtaaga aattcgagaa agataccgga 180 attaaagtca ccgttgagca tccggataaa ctggaagaga aattcccaca ggttgcggca 240 actggcgatg gccctgacat tatcttctgg gcacacgacc gctttggtgg ctacgctcaa 300 tctggcctgt tggctgaaat caccccggac aaagcgttcc aggacaagct gtatccgttt 360 acctgggatg ccgtacgtta caacggcaag ctgattgctt acccgatcgc tgttgaagcg 420 ttatcgctga tttataacaa agatctgctg ccgaacccgc caaaaacctg ggaagagatc 480 ccggcgctgg ataaagaact gaaagcgaaa ggtaagagcg cgctgatgtt caacctgcaa 540 gaaccgtact tcacctggcc gctgattgct gctgacgggg gttatgcgtt caagtatgaa 600 aacggcaagt acgacattaa agacgtgggc gtggataacg ctggcgcgaa agcgggtctg 660 accttcctgg ttgacctgat taaaaacaaa cacatgaatg cagacaccga ttactccatc 720 gcagaagctg cctttaataa aggcgaaaca gcgatgacca tcaacggccc gtgggcatgg 780 tccaacatcg acaccagcaa agtgaattat ggtgtaacgg tactgccgac cttcaagggt 840 caaccatcca aaccgttcgt tggcgtgctg agcgcaggta ttaacgccgc cagtccgaac 900 aaagagctgg cgaaagagtt cctcgaaaac tatctgctga ctgatgaagg tctggaagcg 960 gttaataaag acaaaccgct gggtgccgta gcgctgaagt cttacgagga agagttggcg 1020 aaagatccac gtattgccgc caccatggaa aacgcccaga aaggtgaaat catgccgaac 1080 atcccgcaga tgtccgcttt ctggtatgcc gtgctgatcg aagcccgcac ctcggaatcc 1140 gacacggcag ggcccaacag cgacctggac gtgaacactg acatttattc caaggtgctg 1200 gtgactgcta tatacctggc actcttcgtg gtgggcactg tgggcaactc cgtgacagcc 1260 ttcactctag cgcggaagaa gtcactgcag agcctgcaga gcactgtgca ttaccacctg 1320 ggcagcctgg cactgtcgga cctgcttatc cttctgctgg ccatgcccgt ggagctatac 1380 aacttcatct gggtacacca tccctgggcc tttggggacg ctggctgccg tggctactat 1440 ttcctgcgtg atgcctgcac ctatgccaca gccctcaatg tagccagcct gagtgtggag 1500 cgctacttgg ccatctgcca tcccttcaag gccaagaccc tcatgtcccg cagccgcacc 1560 aagaaattca tcagtgccat atggctagct tcggcgctgc tggctatacc catgcttttc 1620 accatgggcc tgcagaaccg cagtggtgac ggcacgcacc ctggcggcct ggtgtgcaca 1680 cccattgtgg acacagccac tgtcaaggtc gtcatccagg ttaacacctt catgtccttc 1740 ctgtttccca tgttggtcat ctccatccta aacaccgtga ttgccaacaa actgacagtc 1800 atggtgcacc aggccgccga gcagggccga gtgtgcaccg tgggcacaca caacggttta 1860 gagcacagca cgttcaacat gaccatcgag ccgggtcgtg tccaggccct gcgccacgga 1920 gtcctcgtct tacgtgctgt ggtcattgcc tttgtggtct gctggctgcc ctaccacgtg 1980 cgacgcctga tgttctgcta tatctcggat gaacagtgga ctacgttcct cttcgatttc 2040 taccactatt tctacatgct aaccaacgct ctcttctacg tcagctccgc catcaatccc 2100 atcctctaca acctggtctc cgccaacttc cgccaggtct ttctgtccac gctggcctgc 2160 ctttgtcctg ggtggcgcca ccgccgaaag aagaggccaa cgttctccag gaagcccaac 2220 agcatgtcca gcaaccatgc cttttccacc agcgccaccc gggagaccct gtacgcggcc 2280 gcaagcgata aaattattca cctgactgac gacagttttg acacggatgt actcaaagcg 2340 gacggggcga tcctcgtcga tttctgggca gagtggtgcg gtccgtgcaa aatgatcgcc 2400 ccgattctgg atgaaatcgc tgacgaatat cagggcaaac tgaccgttgc aaaactgaac 2460 atcgatcaaa accctggcac tgcgccgaaa tatggcatcc gtggtatccc gactctgctg 2520 ctgttcaaaa acggtgaagt ggcggcaacc aaagtgggtg cactgtctaa aggtcagttg 2580 aaagagttcc tcgacgctaa cctggcggcg gccgcagatt ataaagatga cgatgacaaa 2640 taataaggta cc 26521621626DNAArtificial SequenceGene encoding a fusion protein 162 gtcgacatga aaataaaaac aggtgcacgc atcctcgcat tatccgcatt aacgacgatg 60 atgttttccg cctcggctct cgccaaaatc atcgaagccc gcacctcgga atccgacacg 120 gcagggccca acagcgacct ggacgtgaac actgacattt attccaaggt gctggtgact 180 gctatatacc tggcactctt cgtggtgggc actgtgggca actccgtgac agccttcact 240 ctagcgcgga agaagtcact gcagagcctg cagagcactg tgcattacca cctgggcagc 300 ctggcactgt cggacctgct tatccttctg ctggccatgc ccgtggagct atacaacttc 360 atctgggtac accatccctg ggcctttggg gacgctggct gccgtggcta ctatttcctg 420 cgtgatgcct gcacctatgc cacagccctc aatgtagcca gcctgagtgt ggagcgctac 480 ttggccatct gccatccctt caaggccaag accctcatgt cccgcagccg caccaagaaa 540 ttcatcagtg ccatatggct agcttcggcg ctgctggcta tacccatgct tttcaccatg 600 ggcctgcaga accgcagtgg tgacggcacg caccctggcg gcctggtgtg cacacccatt 660 gtggacacag ccactgtcaa ggtcgtcatc caggttaaca ccttcatgtc cttcctgttt 720 cccatgttgg tcatctccat cctaaacacc gtgattgcca acaaactgac agtcatggtg 780 caccaggccg ccgagcaggg ccgagtgtgc accgtgggca cacacaacgg tttagagcac 840 agcacgttca acatgaccat cgagccgggt cgtgtccagg ccctgcgcca cggagtcctc 900 gtcttacgtg ctgtggtcat tgcctttgtg gtctgctggc tgccctacca cgtgcgacgc 960 ctgatgttct gctatatctc ggatgaacag tggactacgt tcctcttcga tttctaccac 1020 tatttctaca tgctaaccaa cgctctcttc tacgtcagct ccgccatcaa tcccatcctc 1080 tacaacctgg tctccgccaa cttccgccag gtctttctgt ccacgctggc ctgcctttgt 1140 cctgggtggc gccaccgccg aaagaagagg ccaacgttct ccaggaagcc caacagcatg 1200 tccagcaacc atgccttttc caccagcgcc acccgggaga ccctgtacgc ggccgcaagc 1260 gataaaatta ttcacctgac tgacgacagt tttgacacgg atgtactcaa agcggacggg 1320 gcgatcctcg tcgatttctg ggcagagtgg tgcggtccgt gcaaaatgat cgccccgatt 1380 ctggatgaaa tcgctgacga atatcagggc aaactgaccg ttgcaaaact gaacatcgat 1440 caaaaccctg gcactgcgcc gaaatatggc atccgtggta tcccgactct gctgctgttc 1500 aaaaacggtg aagtggcggc aaccaaagtg ggtgcactgt ctaaaggtca gttgaaagag 1560 ttcctcgacg ctaacctggc agcggccgca gattataaag atgacgatga caaataataa 1620 ggtacc 162616326DNAArtificial SequenceCloning primer 163 ggtgcacgca tcctcgcatt atccgc 2616431DNAArtificial SequenceCloning primer 164 cgcacggcat accagaaagc ggacatctgc g 3116543DNAArtificial SequenceCloning primer 165 ccgcggtcga catgaaaata aaaacaggtg cacgcatcct cgc 4316666DNAArtificial SequenceCloning primer 166 gccgtgtcgg attccgaggt gcggccttcg atacgcacgg cataccaaga aagcgggatg 60 ttcggc 6616724DNAArtificial SequenceCloning primer 167 cctcggaatc cgacacggca gggc 2416826DNAArtificial SequenceCloning primer 168 gtacagggtc tcccgggtgg cgctgg 2616943DNAArtificial SequenceCloning primer 169 ccgcgatcga aggccgcacc tcggaatccg acacggcagg gcc 4317073DNAArtificial SequenceCloning primer 170 ggcgcggtac ctttgtcatc gtcatcttta taatctgcgg ccgcgtacag ggtctcccgg 60 gtggcgctgg tgg 7317151DNAArtificial SequenceCloning primer 171 gcggcggtac cttattattt gtcatcgtca tctttataat ctgcggccgc g 5117279DNAArtificial SequenceCloning primer 172 ccgcattaac gacgatgatg ttttccgcct cggctctcgc caaaatcatc gaaggccgca 60 cctcggaatc cgacacggc 7917382DNAArtificial SequenceCloning primer 173 ccgcggtcga catgaaaata aaaacaggtg cacgcatcct cgcattatcc gcattaacga 60 cgatgatgtt ttccgcctcg gc 8217433DNAArtificial SequenceCloning primer 174 ccgcgagcga taaaattatt cacctgactg acg 3317539DNAArtificial SequenceCloning primer 175 gcccgccagg ttagcgtcga ggaactcttt caactgacc 3917637DNAArtificial SequenceCloning primer 176 gcggccgcaa gcgataaaat tattcacctg actgacg 3717738DNAArtificial SequenceCloning primer 177 ggcgctgcgg ccgcatcatc atgatcttta taatcgcc 381782465DNAArtificial SequenceGene encoding a fusion protein 178 gtcgacatgg ggcaacccgg gaacggcagc gccttcttgc tggcacccaa tggaagccat 60 gcgccggacc acgacgtcac gcagcaaagg gacgaggtgt gggtggtggg catgggcatc 120 gtcatgtctc tcatcgtcct ggccatcgtg tttggcaatg tgctggtcat cacagccatt 180 gccaagttcg agcgtctgca gacggtcacc aactacttca tcacttcact ggcctgtgct 240 gatctggtca tgggcctagc agtggtgccc tttggggccg cccatattct tatgaaaatg 300 tggacttttg gcaacttctg gtgcgagttt tggacttcca ttgatgtgct gtgcgtcacg 360 gccagcattg agaccctgtg cgtgatcgca gtggatcgct actttgccat tacttcacct 420 ttcaagtacc agagcctgct gaccaagaat aaggcccggg tgatcattct gatggtgtgg 480 attgtgtcag gccttayctc cttcttgccc attcagatgc actggtacag ggccacccac 540 caggaagcca tcaactgcta tgccaatgag acctgctgtg acttcttcac gaaccaagcc 600 tatgccattg cctcttccat cgtgtccttc tacgttcccc tggtgatcat ggtcttcgtc 660 tactccaggg tctttcagga ggccaaaagg cagctccaga agattgacaa atctgagggc 720 cgcttccatg tccagaacct tagccaggtg gagcaggatg ggcggacggg gcatggactc 780 cgcagatctt ccaagttctg cttgaaggag cacaaagccc tcaagacgtt aggcatcatc 840 atgggcactt tcaccctctg ctggctgccc ttcttcatcg ttaacattgt gcatgtgatc 900 caggataacc tcatccgtaa ggaagtttac atcctcctaa attggatagg ctatgtcaat 960 tctggtttca atccccttat ctactgccgg agcccagatt tcaggattgc cttccaggag 1020 cttctgtgcc tgcgcaggtc ttctttgaag gcctatggca atggctactc cagcaacggc 1080 aacacagggg agcagagtgg atatcacgtg gaacaggaga aagaaaataa actgctgtgt 1140 gaagacctcc caggcacgga agactttgtg ggccatcaag gtactgtgcc tagcgataac 1200 attgattcac aagggaggaa ttgtagtaca aatgactcac tgctagagcg tggccagacg 1260 gtcaccaacc tgcagctcga gggctgcctc gggaacagta agaccgagga ccagcgcaac 1320 gaggagaagg cgcagcgtga ggccaacaaa aagatcgaga agcagctgca gaaggacaag 1380 caggtctacc gggccacgca ccgcctgctg ctgctgggtg ctggagaatc tggtaaaagc 1440 accattgtga agcagatgag gatcctgcat gttaatgggt ttaatggaga cagtgagaag 1500 gcaaccaaag tgcaggacat caaaaacaac ctgaaagagg cgattgaaac cattgtggcc 1560 gccatgagca acctggtgcc ccccgtggag ctggccaacc ccgagaacca gttcagagtg 1620 gactacatcc tgagtgtgat gaacgtgcct gactttgact tccctcccga attctatgag 1680 catgccaagg ctctgtggga ggatgaagga gtgcgtgcct gctacgaacg ctccaacgag 1740 taccagctga ttgactgtgc ccagtacttc ctggacaaga tcgacgtgat caagcaggct 1800 gactatgtgc cgagcgatca ggacctgctt cgctgccgtg tcctgacttc tggaatcttt 1860 gagaccaagt tccaggtgga caaagtcaac ttccacatgt ttgacgtggg tggccagcgc 1920 gatgaacgcc gcaagtggat ccagtgcttc aacgatgtga ctgccatcat cttcgtggtg 1980 gccagcagca gctacaacat ggtcatccgg gaggacaacc agaccaaccg cctgcaggag 2040 gctctgaacc tcttcaagag catctggaac aacagatggc tgcgcaccat ctctgtgatc 2100 ctgttcctca acaagcaaga tctgctcgct gagaaagtcc ttgctgggaa atcgaagatt 2160 gaggactact ttccagaatt tgctcgctac actactcctg aggatgctac tcccgagccc 2220 ggagaggacc cacgcgtgac ccgggccaag tacttcattc gagatgagtt tctgaggatc 2280 agcactgcca gtggagatgg gcgtcactac tgctaccctc atttcacctg cgctgtggac 2340 actgagaaca tccgccgtgt gttcaacgac tgccgtgaca tcattcagcg catgcacctt 2400 cgtcagtacg agctgctcat cgattaataa tctagaggat ccccgcgccc tcatccgaaa 2460 gggcg 24651792485DNAArtificial SequenceGene encoding a fusion protein 179 gtcgacatgg ggcaacccgg gaacggcagc gccttcttgc tggcacccaa tggaagccat 60 gcgccggacc acgacgtcac gcagcaaagg gacgaggtgt gggtggtggg catgggcatc 120 gtcatgtctc tcatcgtcct ggccatcgtg tttggcaatg tgctggtcat cacagccatt 180 gccaagttcg agcgtctgca gacggtcacc aactacttca tcacttcact ggcctgtgct 240 gatctggtca tgggcctagc agtggtgccc tttggggccg cccatattct tatgaaaatg 300 tggacttttg gcaacttctg gtgcgagttt tggacttcca ttgatgtgct gtgcgtcacg 360 gccagcattg agaccctgtg cgtgatcgca gtggatcgct actttgccat tacttcacct 420 ttcaagtacc agagcctgct gaccaagaat aaggcccggg tgatcattct gatggtgtgg 480 attgtgtcag gccttayctc cttcttgccc attcagatgc actggtacag ggccacccac 540 caggaagcca tcaactgcta tgccaatgag acctgctgtg acttcttcac gaaccaagcc 600 tatgccattg cctcttccat cgtgtccttc tacgttcccc tggtgatcat ggtcttcgtc 660 tactccaggg tctttcagga ggccaaaagg cagctccaga agattgacaa atctgagggc 720 cgcttccatg tccagaacct tagccaggtg gagcaggatg ggcggacggg gcatggactc 780 cgcagatctt ccaagttctg cttgaaggag cacaaagccc tcaagacgtt aggcatcatc 840 atgggcactt tcaccctctg ctggctgccc ttcttcatcg ttaacattgt gcatgtgatc 900 caggataacc tcatccgtaa ggaagtttac atcctcctaa attggatagg ctatgtcaat 960 tctggtttca atccccttat ctactgccgg agcccagatt tcaggattgc cttccaggag 1020 cttctgtgcc tgcgcaggtc ttctttgaag gcctatggca atggctactc cagcaacggc 1080 aacacagggg agcagagtgg atatcacgtg gaacaggaga aagaaaataa actgctgtgt 1140 gaagacctcc caggcacgga agactttgtg ggccatcaag gtactgtgcc tagcgataac 1200 attgattcac aagggaggaa ttgtagtaca aatgactcac tgctagagcg tggccagacg 1260 gtcaccaacc tgcagtaata atcaaggagg ccctcgagat gggctgcctc gggaacagta 1320 agaccgagga ccagcgcaac gaggagaagg cgcagcgtga ggccaacaaa aagatcgaga 1380 agcagctgca gaaggacaag caggtctacc gggccacgca ccgcctgctg ctgctgggtg 1440 ctggagaatc tggtaaaagc accattgtga agcagatgag gatcctgcat gttaatgggt 1500 ttaatggaga cagtgagaag gcaaccaaag tgcaggacat caaaaacaac ctgaaagagg 1560 cgattgaaac cattgtggcc gccatgagca acctggtgcc ccccgtggag ctggccaacc 1620 ccgagaacca gttcagagtg gactacatcc tgagtgtgat gaacgtgcct gactttgact 1680 tccctcccga attctatgag catgccaagg ctctgtggga ggatgaagga gtgcgtgcct 1740 gctacgaacg ctccaacgag taccagctga ttgactgtgc ccagtacttc ctggacaaga 1800 tcgacgtgat caagcaggct gactatgtgc cgagcgatca ggacctgctt cgctgccgtg 1860 tcctgacttc tggaatcttt gagaccaagt tccaggtgga caaagtcaac ttccacatgt 1920 ttgacgtggg tggccagcgc gatgaacgcc gcaagtggat ccagtgcttc aacgatgtga 1980 ctgccatcat cttcgtggtg gccagcagca gctacaacat ggtcatccgg gaggacaacc 2040 agaccaaccg cctgcaggag gctctgaacc tcttcaagag catctggaac aacagatggc 2100 tgcgcaccat ctctgtgatc ctgttcctca acaagcaaga tctgctcgct gagaaagtcc 2160 ttgctgggaa atcgaagatt gaggactact ttccagaatt tgctcgctac actactcctg 2220 aggatgctac tcccgagccc ggagaggacc cacgcgtgac ccgggccaag tacttcattc 2280 gagatgagtt tctgaggatc agcactgcca gtggagatgg gcgtcactac tgctaccctc 2340 atttcacctg cgctgtggac actgagaaca tccgccgtgt gttcaacgac tgccgtgaca 2400 tcattcagcg catgcacctt cgtcagtacg agctgctcat cgattaataa tctagaggat 2460 ccccgcgccc tcatccgaaa gggcg 24851801146DNAHomo sapien 180 ctcgagatgg gctgcctcgg gaacagtaag accgaggacc agcgcaacga ggagaaggcg 60 cagcgtgagg ccaacaaaaa gatcgagaag cagctgcaga aggacaagca ggtctaccgg 120 gccacgcacc gcctgctgct gctgggtgct ggagaatctg gtaaaagcac cattgtgaag 180 cagatgagga tcctgcatgt taatgggttt aatggagaca gtgagaaggc aaccaaagtg 240 caggacatca aaaacaacct gaaagaggcg attgaaacca ttgtggccgc catgagcaac 300 ctggtgcccc ccgtggagct ggccaacccc gagaaccagt tcagagtgga ctacatcctg 360 agtgtgatga acgtgcctga ctttgacttc cctcccgaat tctatgagca tgccaaggct 420 ctgtgggagg atgaaggagt gcgtgcctgc tacgaacgct ccaacgagta ccagctgatt 480 gactgtgccc agtacttcct ggacaagatc gacgtgatca agcaggctga ctatgtgccg 540 agcgatcagg acctgcttcg ctgccgtgtc ctgacttctg gaatctttga gaccaagttc 600 caggtggaca aagtcaactt ccacatgttt gacgtgggtg gccagcgcga tgaacgccgc 660 aagtggatcc agtgcttcaa cgatgtgact gccatcatct tcgtggtggc cagcagcagc 720 tacaacatgg tcatccggga ggacaaccag accaaccgcc tgcaggaggc tctgaacctc 780 ttcaagagca tctggaacaa cagatggctg cgcaccatct ctgtgatcct gttcctcaac 840 aagcaagatc tgctcgctga gaaagtcctt gctgggaaat cgaagattga ggactacttt 900 ccagaatttg ctcgctacac tactcctgag gatgctactc ccgagcccgg agaggaccca 960 cgcgtgaccc gggccaagta cttcattcga gatgagtttc tgaggatcag cactgccagt 1020 ggagatgggc gtcactactg ctaccctcat ttcacctgcg ctgtggacac tgagaacatc 1080 cgccgtgtgt tcaacgactg ccgtgacatc attcagcgca tgcaccttcg tcagtacgag 1140 ctgctc 11461811194DNAHomo sapien 181 ctcgagatgg gctgcctcgg gaacagtaag accgaggacc agcgcaacga ggagaaggcg 60 cagcgtgagg ccaacaaaaa gatcgagaag cagctgcaga aggacaagca ggtctaccgg 120 gccacgcacc gcctgctgct gctgggtgct ggagaatctg gtaaaagcac cattgtgaag 180 cagatgagga tcctgcatgt taatgggttt aatggagagg gcggcgaaga ggacccgcag 240 gctgcaagga gcaacagcga tggtgagaag gcaaccaaag tgcaggacat caaaaacaac 300 ctgaaagagg cgattgaaac cattgtggcc gccatgagca acctggtgcc ccccgtggag 360 ctggccaacc ccgagaacca gttcagagtg gactacatcc tgagtgtgat gaacgtgcct 420 gactttgact tccctcccga attctatgag catgccaagg ctctgtggga ggatgaagga 480 gtgcgtgcct gctacgaacg ctccaacgag taccagctga ttgactgtgc ccagtacttc 540 ctggacaaga tcgacgtgat caagcaggct gactatgtgc cgagcgatca ggacctgctt 600 cgctgccgtg tcctgacttc tggaatcttt gagaccaagt tccaggtgga caaagtcaac 660 ttccacatgt ttgacgtggg tggccagcgc gatgaacgcc gcaagtggat ccagtgcttc 720 aacgatgtga ctgccatcat cttcgtggtg gccagcagca gctacaacat ggtcatccgg 780 gaggacaacc agaccaaccg cctgcaggag gctctgaacc tcttcaagag catctggaac 840 aacagatggc tgcgcaccat ctctgtgatc ctgttcctca acaagcaaga tctgctcgct 900 gagaaagtcc ttgctgggaa atcgaagatt gaggactact ttccagaatt tgctcgctac 960 actactcctg aggatgctac tcccgagccc ggagaggacc cacgcgtgac ccgggccaag 1020 tacttcattc gagatgagtt tctgaggatc agcactgcca gtggagatgg gcgtcactac 1080 tgctaccctc atttcacctg cgctgtggac actgagaaca tccgccgtgt gttcaacgac 1140 tgccgtgaca tcattcagcg catgcacctt cgtcagtacg agctgctcat cgat 11941821089DNAHomo sapien 182 ctcgagatga ctctggagtc catcatggcg tgctgcctga gcgaggaggc caaggaagcc 60 cggcggatca acgacgagat cgagcggcag ctccgcaggg acaagcggga cgcccgccgg 120 gagctcaagc tgctgctgct cgggacagga gagagtggca agagtacgtt tatcaagcag 180 atgagaatca tccatgggtc aggatactct gatgaagata aaaggggctt caccaagctg 240 gtgtatcaga acatcttcac ggccatgcag gccatgatca gagccatgga cacactcaag 300 atcccataca agtatgagca caataaggct catgcacaat tagttcgaga agttgatgtg 360 gagaaggtgt ctgcttttga gaatccatat gtagatgcaa taaagagttt atggaatgat 420 cctggaatcc aggaatgcta tgatagacga cgagaatatc aattatctga ctctaccaaa 480 tactatctta atgacttgga ccgcgtagct gaccctgcct acctgcctac gcaacaagat 540 gtgcttagag ttcgagtccc caccacaggg atcatcgaat acccctttga cttacaaagt 600 gtcattttca gaatggtcga tgtagggggc caaaggtcag agagaagaaa atggatacac 660 tgctttgaaa atgtcacctc tatcatgttt ctagtagcgc ttagtgaata tgatcaagtt 720 ctcgtggagt cagacaatga gaaccgaatg gaggaaagca aggctctctt tagaacaatt 780 atcacatacc cctggttcca gaactcctcg gttattctgt tcttaaacaa gaaagatctt 840 ctagaggaga aaatcatgta ttcccatcta gtcgactact tcccagaata tgatggaccc 900 cagagagatg cccaggcagc ccgagaattc attctgaaga tgttcgtgga cctgaaccca 960 gacagtgaca aaattatcta ctcccacttc acgtgcgcca cagacaccga gaatatccgc 1020 tttgtctttg ctgccgtcaa ggacaccatc ctccagttga acctgaagga gtacaatctg 1080 gtcatcgat 10891831077DNAHomo sapien 183 ctcgagatgg gctgcaccgt gagcgccgag gacaaggcgg cggccgagcg ctctaagatg 60 atcgacaaga acctgcggga ggacggagag aaggcggcgc gggaggtgaa gttgctgctg 120 ttgggtgctg gggagtcagg gaagagcacc atcgtcaagc agatgaagat catccacgag 180 gatggctact ccgaggagga atgccggcag taccgggcgg ttgtctacag caacaccatc 240 cagtccatca tggccattgt caaagccatg ggaaacctgc agatcgactt tgccgacccc 300 tccagagcgg acgacgccag gcagctattt gcactgtcct gcaccgccga ggagcaaggc 360 gtgctccctg atgacctgtc cggcgtcatc cggaggctct gggctgacca tggtgtgcag 420 gcctgctttg gccgctcaag ggaataccag ctcaacgact cagctgccta ctacctgaac 480 gacctggagc gtattgcaca gagtgactac atccccacac agcaagatgt gctacggacc 540 cgcgtaaaga ccacggggat cgtggagaca cacttcacct tcaaggacct acacttcaag 600 atgtttgatg tgggtggtca gcggtctgag cggaagaagt ggatccactg ctttgagggc 660 gtcacagcca tcatcttctg cgtagccttg agcgcctatg acttggtgct agctgaggac 720 gaggagatga accgcatgca tgagagcatg aagctattcg atagcatctg caacaacaag 780 tggttcacag acacgtccat catcctcttc ctcaacaaga aggacctgtt tgaggagaag 840 atcacacaca gtcccctgac catctgcttc cctgagtaca caggggccaa caaatatgat 900 gaggcagcca gctacatcca gagtaagttt gaggacctga ataagcgcaa agacaccaag 960 gagatctaca cgcacttcac gtgcgccacc gacaccaaga acgtgcagtt cgtgtttgac 1020 gccgtcaccg atgtcatcat caagaacaac ctgaaggact gcggcctctt catgcat 10771841155DNAHomo sapien 184 ctcgagatgt ccggggtggt gcggaccctc agccgctgcc tgctgccggc cgaggccggc 60 ggggcccgcg agcgcagggc gggcagcggc gcgcgcgacg cggagcgcga ggcccggagg 120 cgtagccgcg acatcgacgc gctgctggcc cgcgagcggc gcgcggtccg gcgcctggtg 180 aagatcctgc tgctgggcgc gggcgagagc ggcaagtcca cgttcctcaa gcagatgcgc 240 atcatccacg gccgcgagtt cgaccagaag gcgctgctgg agttccgcga caccatcttc 300 gacaacatcc tcaagggctc aagggttctt gttgatgcac gagataagct tggcattcct 360 tggcagtatt ctgaaaatga gaagcatggg atgttcctga tggccttcga gaacaaggcg 420 gggctgcctg tggagccggc caccttccag ctgtacgtcc cggccctgag cgcactctgg 480 agggattctg gcatcaggga ggctttcagc cggagaagcg agtttcagct gggggagtcg 540 gtgaagtact tcctggacaa cttggaccgg atcggccagc tgaattactt tcctagtaag 600 caagatatcc tgctggctag gaaagccacc aagggaattg tggagcatga cttcgttatt 660 aagaagatcc cctttaagat ggtggatgtg ggcggccagc ggtcccagcg ccagaagtgg 720 ttccagtgct tcgacgggat cacgtccatc ctgttcatgg tctcctccag cgagtacgac 780 caggtcctca tggaggacag gcgcaccaac cggctggtgg agtccatgaa catcttcgag 840 accatcgtca acaacaagct cttcttcaac gtctccatca ttctcttcct caacaagatg 900 gacctcctgg tggagaaggt gaagaccgtg agcatcaaga agcacttccc ggacttcagg 960 ggcgacccgc accagctgga ggacgtccag cgctacctgg tccagtgctt cgacaggaag 1020 agacggaacc gcagcaagcc actcttccac cacttcacca ccgccatcga caccgagaac 1080 gtccgcttcg tgttccatgc tgtgaaagac accatcctgc aggagaacct gaaggacatc 1140 atgctgcaga tcgat 11551853307DNAArtificial SequenceGene encoding a fusion protein 185 gtcgacatgg ggcaacccgg gaacggcagc gccttcttgc tggcacccaa tggaagccat 60 gcgccggacc acgacgtcac gcagcaaagg gacgaggtgt gggtggtggg catgggcatc 120 gtcatgtctc tcatcgtcct ggccatcgtg tttggcaatg tgctggtcat cacagccatt 180 gccaagttcg agcgtctgca gacggtcacc aactacttca tcacttcact ggcctgtgct 240 gatctggtca tgggcctagc agtggtgccc tttggggccg cccatattct tatgaaaatg 300 tggacttttg gcaacttctg gtgcgagttt tggacttcca ttgatgtgct gtgcgtcacg 360 gccagcattg agaccctgtg cgtgatcgca gtggatcgct actttgccat tacttcacct 420 ttcaagtacc agagcctgct gaccaagaat aaggcccggg tgatcattct gatggtgtgg 480 attgtgtcag gccttayctc cttcttgccc attcagatgc actggtacag ggccacccac 540 caggaagcca tcaactgcta tgccaatgag acctgctgtg acttcttcac gaaccaagcc 600 tatgccattg cctcttccat cgtgtccttc tacgttcccc tggtgatcat ggtcttcgtc 660 tactccaggg tctttcagga ggccaaaagg cagctccaga agattgacaa atctgagggc 720 cgcttccatg tccagaacct tagccaggtg gagcaggatg ggcggacggg gcatggactc 780 cgcagatctt ccaagttctg cttgaaggag cacaaagccc tcaagacgtt aggcatcatc 840 atgggcactt tcaccctctg ctggctgccc ttcttcatcg ttaacattgt gcatgtgatc 900 caggataacc tcatccgtaa ggaagtttac atcctcctaa attggatagg ctatgtcaat 960 tctggtttca atccccttat ctactgccgg agcccagatt tcaggattgc cttccaggag 1020 cttctgtgcc tgcgcaggtc ttctttgaag gcctatggca atggctactc cagcaacggc 1080 aacacagggg agcagagtgg atatcacgtg gaacaggaga aagaaaataa actgctgtgt 1140 gaagacctcc caggcacgga agactttgtg ggccatcaag gtactgtgcc tagcgataac 1200 attgattcac aagggaggaa ttgtagtaca aatgactcac tgctagagcg tggccagacg 1260 gtcaccaacc tgcagggaca caactcaaaa gagatatcga tgagtcatat tggtactaaa 1320 ttcattcttg ctgaaaaatt taccttcgat cccctaagca atactctgat tgacaaagaa 1380 gatagtgaag agatcattcg attaggcagc aacgaaagcc gaattctttg gctgctggcc 1440 caacgtccaa acgaggtaat ttctcgcaat gatttgcatg actttgtttg gcgagagcaa 1500 ggttttgaag tcgatgattc cagcttaacc caagccattt cgactctgcg caaaatgctc 1560 aaagattcga caaagtcccc acaatacgtc aaaacggttc cgaagcgcgg ttaccaattg 1620 atcgcccgag tggaaacggt tgaagaagag atggctcgcg aaaacgaagc tgctcatgac 1680 atctcttaat aatcaaggag gccctcgaga tgggctgcct cgggaacagt aagaccgagg 1740 accagcgcaa cgaggagaag gcgcagcgtg aggccaacaa aaagatcgag aagcagctgc 1800 agaaggacaa gcaggtctac cgggccacgc accgcctgct gctgctgggt gctggagaat 1860 ctggtaaaag caccattgtg aagcagatga ggatcctgca tgttaatggg tttaatggag 1920 acagtgagaa ggcaaccaaa gtgcaggaca tcaaaaacaa cctgaaagag gcgattgaaa 1980 ccattgtggc cgccatgagc aacctggtgc cccccgtgga gctggccaac cccgagaacc 2040 agttcagagt ggactacatc ctgagtgtga tgaacgtgcc tgactttgac ttccctcccg 2100 aattctatga gcatgccaag gctctgtggg aggatgaagg agtgcgtgcc tgctacgaac 2160 gctccaacga gtaccagctg attgactgtg cccagtactt cctggacaag atcgacgtga 2220 tcaagcaggc tgactatgtg ccgagcgatc aggacctgct tcgctgccgt gtcctgactt 2280 ctggaatctt tgagaccaag ttccaggtgg acaaagtcaa cttccacatg tttgacgtgg 2340 gtggccagcg cgatgaacgc cgcaagtgga tccagtgctt caacgatgtg actgccatca 2400 tcttcgtggt ggccagcagc agctacaaca tggtcatccg ggaggacaac cagaccaacc 2460 gcctgcagga ggctctgaac ctcttcaaga gcatctggaa caacagatgg ctgcgcacca 2520 tctctgtgat cctgttcctc aacaagcaag atctgctcgc tgagaaagtc cttgctggga 2580 aatcgaagat tgaggactac tttccagaat ttgctcgcta cactactcct gaggatgcta 2640 ctcccgagcc cggagaggac ccacgcgtga cccgggccaa gtacttcatt cgagatgagt 2700 ttctgaggat cagcactgcc agtggagatg ggcgtcacta ctgctaccct catttcacct 2760 gcgctgtgga cactgagaac atccgccgtg tgttcaacga ctgccgtgac atcattcagc 2820 gcatgcacct tcgtcagtac gagctgctca tcgatggaca caactcaaaa gagatatcga 2880 tgagtcatat tggtactaaa ttcattcttg ctgaaaaatt taccttcgat cccctaagca 2940 atactctgat tgacaaagaa gatagtgaag agatcattcg attaggcagc aacgaaagcc 3000 gaattctttg gctgctggcc caacgtccaa acgaggtaat ttctcgcaat gatttgcatg 3060 actttgtttg gcgagagcaa ggttttgaag tcgatgattc cagcttaacc caagccattt 3120 cgactctgcg caaaatgctc aaagattcga caaagtcccc acaatacgtc aaaacggttc 3180 cgaagcgcgg ttaccaattg atcgcccgag tggaaacggt tgaagaagag atggctcgcg 3240 aaaacgaagc tgctcatgac atctcttaat aatctagagg atccccgcgc cctcatccga 3300 aagggcg 33071863284DNAArtificial SequenceGene encoding a fusion protein 186 tctagaggct gtgggtagaa gtgaaacggg gtttaccgat aaaaacagaa aatgataaaa 60 aaggactaaa tagtatattt tgatttttga tttttgattt caaataatac aaatttattt 120 acttatttaa ttgttttgat caattatttt tctgttaaac aaagggagca ttatatggta 180 aagaccatga ttacggattc actggccgtc gttttacaac gtcgtgactg ggaaaaccct 240 ggcgttaccc aacttaatcg ccttgcagca catccccctt tcgccagctg gcgtaatagc 300 gaagaggccc gcaccgatcg cccttcccaa cagttgcgca gcctgaatgg cgaatggcgc 360 tttgcctggt ttccggcacc agaagcggtg ccggaaagct ggctggagtg cgatcttcct 420 gaggccgata ctgtcgtcgt cccctcaaac tggcagatgc acggttacga tgcgcccatc 480 tacaccaacg tgacctatcc cattacggtc aatccgccgt ttgttcccac ggagaatccg 540 acgggttgtt actcgctcac atttaatgtt gatgaaagct ggctacagga aggccagacg 600 cgaattattt ttgatggcgt taactcggcg tttcatctgt ggtgcaacgg gcgctgggtc 660 ggttacggcc aggacagtcg tttgccgtct gaatttgacc tgagcgcatt tttacgcgcc 720 ggagaaaacc gcctcgcggt gatggtgctg cgctggagtg acggcagtta tctggaagat 780 caggatatgt ggcggatgag cggcattttc cgtgacgtct cgttgctgca taaaccgact 840 acacaaatca gcgatttcca tgttgccact cgctttaatg atgatttcag ccgcgctgta 900 ctggaggctg aagttcagat gtgcggcgag ttgcgtgact acctacgggt aacagtttct 960 ttatggcagg gtgaaacgca ggtcgccagc ggcaccgcgc ctttcggcgg tgaaattatc 1020 gatgagcgtg gtggttatgc cgatcgcgtc acactacgtc tgaacgtcga aaacccgaaa 1080 ctgtggagcg ccgaaatccc gaatctctat cgtgcggtgg ttgaactgca caccgccgac 1140 ggcacgctga ttgaagcaga agcctgcgat gtcggtttcc gcgaggtgcg gattgaaaat 1200 ggtctgctgc tgctgaacgg caagccgttg ctgattcgag gcgttaaccg tcacgagcat 1260 catcctctgc atggtcaggt catggatgag cagacgatgg tgcaggatat cctgctgatg 1320 aagcagaaca actttaacgc cgtgcgctgt tcgcattatc cgaaccatcc gctgtggtac 1380 acgctgtgcg accgctacgg cctgtatgtg gtggatgaag ccaatattga aacccacggc 1440 atggtgccaa tgaatcgtct gaccgatgat ccgcgctggc taccggcgat gagcgaacgc 1500 gtaacgcgaa tggtgcagcg cgatcgtaat cacccgagtg tgatcatctg gtcgctgggg 1560 aatgaatcag gccacggcgc taatcacgac gcgctgtatc gctggatcaa atctgtcgat 1620 ccttcccgcc cggtgcagta tgaaggcggc ggagccgaca ccacggccac cgatattatt 1680 tgcccgatgt acgcgcgcgt ggatgaagac cagcccttcc cggctgtgcc gaaatggtcc 1740 atcaaaaaat ggctttcgct acctggagag acgcgcccgc tgatcctttg cgaatacgcc 1800 cacgcgatgg gtaacagtct tggcggtttc gctaaatact ggcaggcgtt tcgtcagtat 1860 ccccgtttac agggcggctt cgtctgggac tgggtggatc agtcgctgat taaatatgat 1920 gaaaacggca acccgtggtc ggcttacggc ggtgattttg gcgatacgcc gaacgatcgc 1980 cagttctgta tgaacggtct ggtctttgcc gaccgcacgc cgcatccagc gctgacggaa 2040 gcaaaacacc agcagcagtt tttccagttc cgtttatccg ggcaaaccat cgaagtgacc 2100 agcgaatacc tgttccgtca tagcgataac gagctcctgc actggatggt ggcgctggat 2160 ggtaagccgc tggcaagcgg tgaagtgcct ctggatgtcg ctccacaagg taaacagttg 2220 attgaactgc ctgaactacc gcagccggag agcgccgggc aactctggct cacagtacgc 2280 gtagtgcaac cgaacgcgac cgcatggtca gaagccgggc acatcagcgc ctggcagcag 2340 tggcgtctgg cggaaaacct cagtgtgacg ctccccgccg cgtcccacgc catcccgcat 2400 ctgaccacca gcgaaatgga tttttgcatc gagctgggta ataagcgttg gcaatttaac 2460 cgccagtcag gctttctttc acagatgtgg attggcgata aaaaacaact gctgacgccg 2520 ctgcgcgatc agttcacccg tgcaccgctg gataacgaca ttggcgtaag tgaagcgacc 2580 cgcattgacc ctaacgcctg ggtcgaacgc tggaaggcgg cgggccatta ccaggccgaa 2640 gcagcgttgt tgcagtgcac ggcagataca cttgctgatg cggtgctgat tacgaccgct 2700 cacgcgtggc agcatcaggg gaaaacctta tttatcagcc ggaaaaccta ccggattgat 2760 ggtagtggtc aaatggcgat taccgttgat gttgaagtgg cgagcgatac accgcatccg 2820 gcgcggattg gcctgaactg ccagctggcg caggtagcag agcgggtaaa ctggctcgga 2880 ttagggccgc aagaaaacta tcccgaccgc cttactgccg cctgttttga ccgctgggat 2940 ctgccattgt cagacatgta taccccgtac gtcttcccga gcgaaaacgg tctgcgctgc 3000 gggacgcgcg aattgaatta tggcccacac cagtggcgcg gcgacttcca gttcaacatc 3060 agccgctaca gtcaacagca actgatggaa accagccatc gccatctgct gcacgcggaa 3120 gaaggcacat ggctgaatat cgacggtttc catatgggga ttggtggcga cgactcctgg 3180 agcccgtcag tatcggcgga attccagctg agcgccggtc gctaccatta ccagttggtc 3240 tggtgtcaaa aataataacg ccctcatccg aaagggcgtc taga 328418725DNAArtificial SequenceCloning primer 187 ggggcaaccc gggaacggca gcgcc 2518830DNAArtificial SequenceCloning primer 188 gcagtgagtc atttgtacta caattcctcc 3018937DNAArtificial SequenceCloning primer 189 cgcggtcgac atggggcaac ccgggaacgg cagcgcc 3719067DNAArtificial SequenceCloning primer 190 ggctcgagct gcaggttggt gaccgtctgg ccacgctcta gcagtgagtc atttgtacta 60 caattcc 6719129DNAArtificial SequenceCloning primer 191 gggctgcctc gggaacagta agaccgagg 2919229DNAArtificial SequenceCloning primer 192 gagcagctcg tactgacgaa ggtgcatgc 2919344DNAArtificial SequenceCloning primer 193 ggaggccctc gagatgggct gcctcgggaa cagtaagacc gagg 4419448DNAArtificial SequenceCloning primer 194 cctctagatt attatcgatg agcagctcgt actgacgaag gtgcatgc 4819537DNAArtificial SequenceCloning primer 195 ccatcgatga gcagctcgta ctgacgaagg tgcatgc 3719626DNAArtificial SequenceCloning primer 196 ccggggtggt gcggaccctc agccgc 2619728DNAArtificial SequenceCloning primer 197 ctgcagcatg atgtccttca ggttctcc 2819841DNAArtificial SequenceCloning primer 198 gcgggctcga gatgtccggg gtggtgcgga ccctcagccg c 4119939DNAArtificial SequenceCloning primer 199 gcgccatcga tctgcagcat gatgtccttc aggttctcc 3920028DNAArtificial SequenceCloning primer 200 gactctggag tccatcatgg cgtgctgc 2820129DNAArtificial SequenceCloning primer 201 ccagattgta ctccttcagg ttcaactgg 2920230DNAArtificial SequenceCloning primer 202 atgactctgg agtccatcat ggcgtgctgc 3020342DNAArtificial SequenceCloning primer 203 gcgccatcga tgaccagatt gtactccttc aggttcaact gg 4220429DNAArtificial SequenceCloning primer 204 gggctgcacc gtgagcgccg aggacaagg 2920530DNAArtificial SequenceCloning primer 205 ccttcaggtt gttcttgatg atgacatcgg 3020631DNAArtificial SequenceCloning primer 206 atgggctgca ccgtgagcgc cgaggacaag g 3120755DNAArtificial SequenceCloning primer 207 gcgccatcga tgaagaggcc gcagtccttc aggttgttct tgatgatgac atcgg 5520829DNAArtificial SequenceCloning primer 208 gggctgcctc gggaacagta agaccgagg 2920929DNAArtificial SequenceCloning primer 209 gagcagctcg tactgacgaa ggtgcatgc 2921031DNAArtificial SequenceCloning primer 210 atgggctgcc tcgggaacag taagaccgag g 3121140DNAArtificial SequenceCloning primer 211 gcgccatcga tgagcagctc gtactgacga aggtgcatgc 40212107DNAArtificial SequenceCloning primer 212 ggctcgaggg cctccttgat tattactcga gggcctcctt gattattact gcaggttggt 60 gaccgtctgg ccacgctcta gcagtgagtc atttgtacta caattcc 10721361DNAArtificial SequenceCloning primer 213 ccctgcaggt tggtgaccgt ctggccacgc tctagcagtg agtcatttgt actacaattc 60 c 6121438DNAArtificial SequenceCloning primer 214 ggacacaact caaaagagat atcgatgagt catattgg 3821529DNAArtificial SequenceCloning primer 215 gagatgtcat gagcagcttc gttttcgcg 2921652DNAArtificial SequenceCloning primer 216 gcgtggccag acggtcacca acctgcaggg acacaactca aaagagatat cg 5221751DNAArtificial SequencePrimer 217 cggggatcct ctagattatt aagagatgtc atgagcagct tcgttttcgc g 5121832DNAArtificial SequenceCloning primer 218 ggctgtgggt agaagtgaaa cggggtttac cg 3221932DNAArtificial SequenceCloning primer 219 ctttaccata taatgctccc tttgtttaac ag 3222043DNAArtificial SequenceCloning primer 220 cgcggtctag aggctgtggg tagaagtgaa acggggttta ccg 4322160DNAArtificial SequenceCloning primer 221 cgacggccag tgaatccgta atcatggtct ttaccatata atgctccctt tgtttaacag 6022227DNAArtificial SequenceCloning primer 222 ccatgattac ggattcactg gccgtcg 2722327DNAArtificial SequenceCloning primer 223 ccagaccaac tggtaatggt agcgacc 2722435DNAArtificial SequenceCloning primer 224 ggtaaagacc atgattacgg attcactggc cgtcg 3522577DNAArtificial SequenceCloning primer 225 gcgcctctag aaatacgccc tttcggatga gggcgttatt atttttgaca ccagaccaac 60 tggtaatggt agcgacc 7722689DNAArtificial SequenceCloning primer 226 cgcggatgca tatgaaaata aaaacaggtg cacgcatcct cgcattatcc gcattaacga 60 cgatgatgtt ttccgcctcg gctctcgcc 8922769DNAArtificial SequenceCloning primer 227 cgtcgaccga ggcctgcagg cgggcttcga tgattttggc gagagccgag gcggaaaaca 60 tcatcgtcg 6922881DNAArtificial SequenceCloning primer 228 cgaagcccgc ctgcaggcct cggtcgacgc cgaatctaga gattataaag atgacgatga 60 caaataataa gctagcggcg c 8122927DNAArtificial SequenceCloning primer 229 gcgccgctag cttattattt gtcatcg 2723026DNAArtificial SequenceCloning primer 230 ggtgcacgca tcctcgcatt atccgc 2623130DNAArtificial SequenceCloning primer 231 ggcgttttcc atggtggcgg caatacgtgg 3023252DNAArtificial SequenceCloning primer 232 cgcggatgca tatgaaaata aaaacaggtg cacgcatcct cgcattatcc gc 5223382DNAArtificial SequenceCloning primer 233 ccgaggcctg caggcgggct tcgatacgca cggcatacca gaaagcggac tgggcgtttt 60 ccatggtggc ggcaatacgt gg 8223487DNAArtificial SequenceCloning primer 234 gcgccgctag cttattattt gtcatcgtca tctttataat ctctagattc ggcgtcgacc 60 gaggcctgca ggcgggcttc gatacgc 8723526DNAArtificial SequenceCloning primer 235 cctgactgac gacagttttg acacgg 2623632DNAArtificial SequenceCloning primer 236 cctttagaca gtgcacccac tttggttgcc gc 3223778DNAArtificial SequenceCloning primer 237 cgcggctgca ggcctcggtc gacgccgaat ctagaagcga taaaattatt cacctgactg 60 acgacagttt tgacacgg 7823895DNAArtificial SequenceCloning primer 238 gcgccgctag cttattattt gtcatcgtca tctttataat ccgccaggtt ctctttcaac 60 tgacctttag acagtgcacc cactttggtt gccgc 95239216DNAArtificial SequenceFusion vector 239 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc atatgaaaat 60 aaaaacaggt gcacgcatcc tcgcattatc cgcattaacg acgatgatgt tttccgcctc 120 ggctctcgcc aaaatcatcg aagcccgcct gcaggcctcg gtcgacgccg aatctagaga 180 ttataaagat gacgatgaca aataataagc tagagg 216240202DNAArtificial SequenceFusion vector 240 ccatacccgt ttttttgggc tagcaggagg ccctgcatat gaaaataaaa acaggtgcac 60 gcatcctcgc attatccgca ttaacgacga tgatgttttc cgcctcggct ctcgccaaaa 120 tcatcgaagc ccgcctgcag gcctcggtcg acgccgaatc tagagattat aaagatgacg 180 atgacaaata ataagctaga gg 202241182DNAArtificial SequenceFusion vector 241 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcat cgaagcccgc ctgcaggcct 120 cggtcgacgc cgaatctaga gattataaag atgacgatga caaataataa gctagaggta 180 cc 182242182DNAArtificial SequenceFusion vector 242 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcat cgaagcccgc ctgcaggcct 120 cggtcgacgc cgaatctaga gattataaag atgacgatga caaataataa gctagaggta 180 cc 1822431080DNAArtificial SequenceFusion vector 243 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc atatgaaaat 60 aaaaacaggt gcacgcatcc tcgcattatc cgcattaacg acgatgatgt tttccgcctc 120 ggctctcgcc aaaatcgaag aaggtaaact ggtaatctgg attaacggcg ataaaggcta 180 taacggtctc gctgaagtcg gtaagaaatt cgagaaagat accggaatta aagtcaccgt 240 tgagcatccg gataaactgg aagagaaatt cccacaggtt gcggcaactg gcgatggccc 300 tgacattatc ttctgggcac acgaccgctt tggtggctac gctcaatctg gcctgttggc 360 tgaaatcacc ccggacaaag cgttccagga caagctgtat ccgtttacct gggatgccgt 420 acgttacaac ggcaagctga ttgcttaccc gatcgctgtt gaagcgttat cgctgattta 480 taacaaagat ctgctgccga acccgccaaa aacctgggaa gagatcccgg cgctggataa 540 agaactgaaa gcgaaaggta agagcgcgct gatgttcaac ctgcaagaac cgtacttcac 600 ctggccgctg attgctgctg acgggggtta tgcgttcaag tatgaaaacg gcaagtacga 660 cattaaagac gtgggcgtgg ataacgctgg cgcgaaagcg ggtctgacct tcctggttga 720 cctgattaaa aacaaacaca tgaatgcaga caccgattac tccatcgcag aagctgcctt 780 taataaaggc gaaacagcga tgaccatcaa cggcccgtgg gcatggtcca acatcgacac 840 cagcaaagtg aattatggtg taacggtact gccgaccttc aagggtcaac catccaaacc 900 gttcgttggc gtgctgagcg caggtattaa cgccgccagt ccgaacaaag agctggcgaa 960 agagttcctc gaaaactatc tgctgactga tgaaggtctg gaagcggtta ataaagacaa 1020 accgctgggt gccgtagcgc tgaagtctta cgaggaagag ttggcgaaag atccacgtat 10802441196DNAArtificial SequenceFusion vector 244 ccatacccgt ttttttgggc tagcaggagg ccctgcatat gaaaataaaa acaggtgcac 60 gcatcctcgc attatccgca ttaacgacga tgatgttttc cgcctcggct ctcgccaaaa 120 tcgaagaagg taaactggta atctggatta acggcgataa aggctataac ggtctcgctg 180 aagtcggtaa gaaattcgag aaagataccg gaattaaagt caccgttgag catccggata 240 aactggaaga gaaattccca caggttgcgg caactggcga tggccctgac attatcttct 300 gggcacacga ccgctttggt ggctacgctc aatctggcct gttggctgaa atcaccccgg 360 acaaagcgtt ccaggacaag ctgtatccgt ttacctggga tgccgtacgt tacaacggca 420 agctgattgc ttacccgatc gctgttgaag cgttatcgct gatttataac aaagatctgc 480 tgccgaaccc gccaaaaacc tgggaagaga tcccggcgct ggataaagaa ctgaaagcga 540 aaggtaagag cgcgctgatg ttcaacctgc aagaaccgta cttcacctgg ccgctgattg 600 ctgctgacgg gggttatgcg ttcaagtatg aaaacggcaa gtacgacatt aaagacgtgg 660 gcgtggataa cgctggcgcg aaagcgggtc tgaccttcct ggttgacctg attaaaaaca 720 aacacatgaa tgcagacacc gattactcca tcgcagaagc tgcctttaat aaaggcgaaa 780 cagcgatgac catcaacggc ccgtgggcat ggtccaacat cgacaccagc aaagtgaatt 840 atggtgtaac ggtactgccg accttcaagg gtcaaccatc caaaccgttc gttggcgtgc 900 tgagcgcagg tattaacgcc gccagtccga acaaagagct ggcgaaagag ttcctcgaaa 960 actatctgct gactgatgaa ggtctggaag cggttaataa agacaaaccg ctgggtgccg 1020 tagcgctgaa gtcttacgag gaagagttgg cgaaagatcc acgtattgcc gccaccatgg 1080 aaaacgccca gtccgctttc tggtatgccg tgcgtatcga agcccgcctg caggcctcgg 1140 tcgacgccga atctagagat tataaagatg acgatgacaa ataataagct agagga 11962451171DNAArtificial SequenceFusion vector 245 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcga agaaggtaaa ctggtaatct 120 ggattaacgg cgataaaggc tataacggtc tcgctgaagt cggtaagaaa ttcgagaaag 180 ataccggaat taaagtcacc gttgagcatc cggataaact ggaagagaaa ttcccacagg 240 ttgcggcaac tggcgatggc cctgacatta tcttctgggc acacgaccgc tttggtggct 300 acgctcaatc tggcctgttg gctgaaatca ccccggacaa agcgttccag gacaagctgt 360 atccgtttac ctgggatgcc gtacgttaca acggcaagct gattgcttac ccgatcgctg 420 ttgaagcgtt atcgctgatt tataacaaag atctgctgcc gaacccgcca aaaacctggg 480 aagagatccc ggcgctggat aaagaactga aagcgaaagg taagagcgcg ctgatgttca 540 acctgcaaga accgtacttc acctggccgc tgattgctgc tgacgggggt tatgcgttca 600 agtatgaaaa cggcaagtac gacattaaag acgtgggcgt ggataacgct ggcgcgaaag 660 cgggtctgac cttcctggtt gacctgatta aaaacaaaca catgaatgca gacaccgatt 720 actccatcgc agaagctgcc tttaataaag gcgaaacagc gatgaccatc aacggcccgt 780 gggcatggtc caacatcgac accagcaaag tgaattatgg tgtaacggta ctgccgacct 840 tcaagggtca accatccaaa ccgttcgttg gcgtgctgag cgcaggtatt aacgccgcca 900 gtccgaacaa agagctggcg aaagagttcc tcgaaaacta tctgctgact gatgaaggtc 960 tggaagcggt taataaagac aaaccgctgg gtgccgtagc gctgaagtct tacgaggaag 1020 agttggcgaa agatccacgt attgccgcca ccatggaaaa cgcccagtcc gctttctggt 1080 atgccgtgcg tatcgaagcc cgcctgcagg cctcggtcga cgccgaatct agagattata 1140 aagatgacga tgacaaataa taagctagag g 11712461171DNAArtificial SequenceFusion vector 246 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcga agaaggtaaa ctggtaatct 120 ggattaacgg cgataaaggc tataacggtc tcgctgaagt cggtaagaaa ttcgagaaag 180 ataccggaat taaagtcacc gttgagcatc cggataaact ggaagagaaa ttcccacagg 240 ttgcggcaac tggcgatggc cctgacatta tcttctgggc acacgaccgc tttggtggct 300 acgctcaatc tggcctgttg gctgaaatca ccccggacaa agcgttccag gacaagctgt 360 atccgtttac ctgggatgcc gtacgttaca acggcaagct gattgcttac ccgatcgctg 420 ttgaagcgtt atcgctgatt tataacaaag atctgctgcc gaacccgcca aaaacctggg 480 aagagatccc ggcgctggat aaagaactga aagcgaaagg taagagcgcg ctgatgttca 540 acctgcaaga accgtacttc acctggccgc tgattgctgc tgacgggggt tatgcgttca 600 agtatgaaaa cggcaagtac gacattaaag acgtgggcgt ggataacgct ggcgcgaaag 660 cgggtctgac cttcctggtt gacctgatta aaaacaaaca catgaatgca gacaccgatt 720 actccatcgc agaagctgcc tttaataaag gcgaaacagc gatgaccatc aacggcccgt 780 gggcatggtc caacatcgac accagcaaag tgaattatgg tgtaacggta ctgccgacct 840 tcaagggtca accatccaaa ccgttcgttg gcgtgctgag cgcaggtatt aacgccgcca 900 gtccgaacaa agagctggcg aaagagttcc tcgaaaacta tctgctgact gatgaaggtc 960 tggaagcggt taataaagac aaaccgctgg gtgccgtagc gctgaagtct tacgaggaag 1020 agttggcgaa agatccacgt attgccgcca ccatggaaaa cgcccagtcc gctttctggt 1080 atgccgtgcg tatcgaagcc cgcctgcagg cctcggtcga cgccgaatct agagattata 1140 aagatgacga tgacaaataa taagctagag g 1171247392DNAArtificial SequenceFusion vector 247 tagcaggagg ccctgcaggc ctcggtcgac gccgaatcta gaagcgataa aattattcac 60 ctgactgacg acagttttga cacggatgta ctcaaagcgg acggggcgat cctcgtcgat 120 ttctgggcag agtggtgcgg tccgtgcaaa atgatcgccc cgattctgga tgaaatcgct 180 gacgaatatc agggcaaact gaccgttgca aaactgaaca tcgatcaaaa ccctggcact 240 gcgccgaaat atggcatccg tggtatcccg actctgctgc tgttcaaaaa cggtgaagtg 300 gcggcaacca aagtgggtgc actgtctaaa ggtcagttga aagagaacct ggcggattat 360 aaagatgacg atgacaaata ataagctaga gg 392248426DNAArtificial SequenceFusion vector 248 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc aggcctcggt 60 cgacgccgaa tctagaagcg ataaaattat tcacctgact gacgacagtt ttgacacgga 120 tgtactcaaa gcggacgggg cgatcctcgt cgatttctgg gcagagtggt gcggtccgtg 180 caaaatgatc gccccgattc tggatgaaat cgctgacgaa tatcagggca aactgaccgt 240 tgcaaaactg aacatcgatc aaaaccctgg cactgcgccg aaatatggca tccgtggtat 300 cccgactctg ctgctgttca aaaacggtga agtggcggca accaaagtgg gtgcactgtc 360 taaaggtcag ttgaaagaga acctggcgga ttataaagat gacgatgaca aataataagc 420 tagagg 426249392DNAArtificial SequenceFusion vector 249 aggaggttct gcaggcctcg gtcgacgccg aatctagaag cgataaaatt attcacctga 60 ctgacgacag ttttgacacg gatgtactca aagcggacgg ggcgatcctc gtcgatttct 120 gggcagagtg gtgcggtccg tgcaaaatga tcgccccgat tctggatgaa atcgctgacg 180 aatatcaggg caaactgacc gttgcaaaac tgaacatcga tcaaaaccct ggcactgcgc 240 cgaaatatgg catccgtggt atcccgactc tgctgctgtt caaaaacggt gaagtggcgg 300 caaccaaagt gggtgcactg tctaaaggtc agttgaaaga gaacctggcg gattataaag 360 atgacgatga caaataataa gctagaggta cc 392250392DNAArtificial SequenceFusion vector 250 aggaggttct gcaggcctcg gtcgacgccg aatctagaag cgataaaatt attcacctga 60 ctgacgacag ttttgacacg gatgtactca aagcggacgg ggcgatcctc gtcgatttct 120 gggcagagtg gtgcggtccg tgcaaaatga tcgccccgat tctggatgaa atcgctgacg 180 aatatcaggg caaactgacc gttgcaaaac tgaacatcga tcaaaaccct ggcactgcgc 240 cgaaatatgg catccgtggt atcccgactc tgctgctgtt caaaaacggt gaagtggcgg 300 caaccaaagt gggtgcactg tctaaaggtc agttgaaaga gaacctggcg gattataaag 360 atgacgatga caaataataa gctagaggta cc 392251528DNAArtificial SequenceGene encoding a fusion protein 251 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc atatgaaaat 60 aaaaacaggt gcacgcatcc tcgcattatc cgcattaacg acgatgatgt tttccgcctc 120 ggctctcgcc aaaatcatcg aagcccgcct gcaggcctcg gtcgacgccg aatctagaag 180 cgataaaatt attcacctga ctgacgacag ttttgacacg gatgtactca aagcggacgg 240 ggcgatcctc gtcgatttct gggcagagtg gtgcggtccg tgcaaaatga tcgccccgat 300 tctggatgaa atcgctgacg aatatcaggg caaactgacc gttgcaaaac tgaacatcga 360 tcaaaaccct ggcactgcgc cgaaatatgg catccgtggt atcccgactc tgctgctgtt 420 caaaaacggt gaagtggcgg caaccaaagt gggtgcactg tctaaaggtc agttgaaaga 480 gaacctggcg gattataaag atgacgatga caaataataa gctagagg 528252514DNAArtificial SequenceGene encoding a fusion protein 252 ccatacccgt ttttttgggc tagcaggagg ccctgcatat gaaaataaaa acaggtgcac 60 gcatcctcgc attatccgca ttaacgacga tgatgttttc cgcctcggct ctcgccaaaa 120 tcatcgaagc ccgcctgcag gcctcggtcg acgccgaatc tagaagcgat aaaattattc 180 acctgactga cgacagtttt gacacggatg tactcaaagc ggacggggcg atcctcgtcg 240 atttctgggc agagtggtgc ggtccgtgca aaatgatcgc cccgattctg gatgaaatcg 300 ctgacgaata tcagggcaaa ctgaccgttg caaaactgaa catcgatcaa aaccctggca 360 ctgcgccgaa atatggcatc cgtggtatcc cgactctgct gctgttcaaa aacggtgaag 420 tggcggcaac caaagtgggt gcactgtcta aaggtcagtt gaaagagaac ctggcggatt 480 ataaagatga cgatgacaaa taataagcta gagg 514253494DNAArtificial SequenceGene encoding a fusion protein 253 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcat cgaagcccgc ctgcaggcct 120 cggtcgacgc cgaatctaga agcgataaaa ttattcacct gactgacgac agttttgaca 180 cggatgtact caaagcggac ggggcgatcc tcgtcgattt ctgggcagag tggtgcggtc 240 cgtgcaaaat gatcgccccg attctggatg aaatcgctga cgaatatcag ggcaaactga 300 ccgttgcaaa actgaacatc gatcaaaacc ctggcactgc gccgaaatat ggcatccgtg 360 gtatcccgac tctgctgctg ttcaaaaacg gtgaagtggc ggcaaccaaa gtgggtgcac 420 tgtctaaagg tcagttgaaa gagaacctgg cggattataa agatgacgat gacaaataat 480 aagctagagg tacc 494254494DNAArtificial SequenceGene encoding a fusion protein 254 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcat cgaagcccgc ctgcaggcct 120 cggtcgacgc cgaatctaga agcgataaaa ttattcacct gactgacgac agttttgaca 180 cggatgtact caaagcggac ggggcgatcc tcgtcgattt ctgggcagag tggtgcggtc 240 cgtgcaaaat gatcgccccg attctggatg aaatcgctga cgaatatcag ggcaaactga 300 ccgttgcaaa actgaacatc gatcaaaacc ctggcactgc gccgaaatat ggcatccgtg 360 gtatcccgac tctgctgctg ttcaaaaacg gtgaagtggc ggcaaccaaa gtgggtgcac 420 tgtctaaagg tcagttgaaa gagaacctgg cggattataa agatgacgat gacaaataat 480 aagctagagg tacc 4942551521DNAArtificial SequenceGene encoding a fusion protein 255 gaattcaggc gctttttaga ctggtcgtaa tgaaattcag gaggttctgc atatgaaaat 60 aaaaacaggt gcacgcatcc tcgcattatc cgcattaacg acgatgatgt tttccgcctc 120 ggctctcgcc aaaatcgaag aaggtaaact ggtaatctgg attaacggcg ataaaggcta 180 taacggtctc gctgaagtcg gtaagaaatt cgagaaagat accggaatta aagtcaccgt 240 tgagcatccg gataaactgg aagagaaatt cccacaggtt gcggcaactg gcgatggccc 300 tgacattatc ttctgggcac acgaccgctt tggtggctac gctcaatctg gcctgttggc 360 tgaaatcacc ccggacaaag cgttccagga caagctgtat ccgtttacct gggatgccgt 420 acgttacaac ggcaagctga ttgcttaccc gatcgctgtt gaagcgttat cgctgattta 480 taacaaagat ctgctgccga acccgccaaa aacctgggaa gagatcccgg cgctggataa 540 agaactgaaa gcgaaaggta agagcgcgct gatgttcaac ctgcaagaac cgtacttcac 600 ctggccgctg attgctgctg acgggggtta tgcgttcaag tatgaaaacg gcaagtacga 660 cattaaagac gtgggcgtgg ataacgctgg cgcgaaagcg ggtctgacct tcctggttga 720 cctgattaaa aacaaacaca tgaatgcaga caccgattac tccatcgcag aagctgcctt 780 taataaaggc gaaacagcga tgaccatcaa cggcccgtgg gcatggtcca acatcgacac 840 cagcaaagtg aattatggtg taacggtact gccgaccttc aagggtcaac catccaaacc 900 gttcgttggc gtgctgagcg caggtattaa cgccgccagt ccgaacaaag agctggcgaa 960 agagttcctc gaaaactatc tgctgactga tgaaggtctg gaagcggtta ataaagacaa 1020 accgctgggt gccgtagcgc tgaagtctta cgaggaagag ttggcgaaag atccacgtat 1080 tgccgccacc atggaaaacg cccagtccgc tttctggtat gccgtgcgta tcgaagcccg 1140 cctgcaggcc tcggtcgacg ccgaatctag aagcgataaa attattcacc tgactgacga 1200 cagttttgac acggatgtac tcaaagcgga cggggcgatc ctcgtcgatt tctgggcaga 1260 gtggtgcggt ccgtgcaaaa tgatcgcccc gattctggat gaaatcgctg acgaatatca 1320 gggcaaactg accgttgcaa aactgaacat cgatcaaaac cctggcactg cgccgaaata 1380 tggcatccgt ggtatcccga ctctgctgct gttcaaaaac ggtgaagtgg cggcaaccaa 1440 agtgggtgca ctgtctaaag gtcagttgaa agagaacctg gcggattata aagatgacga 1500 tgacaaataa taagctagag g 15212561500DNAArtificial SequenceGene encoding a fusion protein 256 ccatacccgt ttttttgggc tagcaggagg ccctgcatat gaaaataaaa acaggtgcac 60 gcatcctcgc attatccgca ttaacgacga tgatgttttc cgcctcggct ctcgccaaaa 120 tcgaagaagg taaactggta atctggatta acggcgataa aggctataac ggtctcgctg 180 aagtcggtaa gaaattcgag aaagataccg gaattaaagt caccgttgag catccggata 240 aactggaaga gaaattccca caggttgcgg caactggcga tggccctgac attatcttct 300 gggcacacga ccgctttggt ggctacgctc aatctggcct gttggctgaa atcaccccgg 360 acaaagcgtt ccaggacaag ctgtatccgt ttacctggga tgccgtacgt tacaacggca 420 agctgattgc ttacccgatc gctgttgaag cgttatcgct gatttataac aaagatctgc 480 tgccgaaccc gccaaaaacc tgggaagaga tcccggcgct ggataaagaa ctgaaagcga 540 aaggtaagag cgcgctgatg ttcaacctgc aagaaccgta cttcacctgg ccgctgattg 600 ctgctgacgg gggttatgcg ttcaagtatg aaaacggcaa gtacgacatt aaagacgtgg 660 gcgtggataa cgctggcgcg aaagcgggtc tgaccttcct ggttgacctg attaaaaaca 720 aacacatgaa tgcagacacc gattactcca tcgcagaagc tgcctttaat aaaggcgaaa 780 cagcgatgac catcaacggc ccgtgggcat ggtccaacat cgacaccagc aaagtgaatt 840 atggtgtaac ggtactgccg accttcaagg gtcaaccatc caaaccgttc gttggcgtgc 900 tgagcgcagg tattaacgcc gccagtccga acaaagagct ggcgaaagag ttcctcgaaa 960 actatctgct gactgatgaa ggtctggaag cggttaataa agacaaaccg ctgggtgccg 1020 tagcgctgaa gtcttacgag gaagagttgg cgaaagatcc acgtattgcc gccaccatgg 1080 aaaacgccca gtccgctttc tggtatgccg tgcgtatcga agcccgcctg caggcctcgg 1140 tcgacgccga atctagaagc gataaaatta ttcacctgac tgacgacagt tttgacacgg 1200 atgtactcaa agcggacggg gcgatcctcg tcgatttctg ggcagagtgg tgcggtccgt 1260 gcaaaatgat cgccccgatt ctggatgaaa tcgctgacga atatcagggc aaactgaccg 1320 ttgcaaaact gaacatcgat caaaaccctg gcactgcgcc gaaatatggc atccgtggta 1380 tcccgactct gctgctgttc aaaaacggtg aagtggcggc aaccaaagtg ggtgcactgt 1440 ctaaaggtca gttgaaagag aacctggcgg attataaaga tgacgatgac aaataataag 15002571476DNAArtificial SequenceGene encoding a fusion protein 257 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcga agaaggtaaa ctggtaatct 120 ggattaacgg cgataaaggc tataacggtc tcgctgaagt cggtaagaaa ttcgagaaag 180 ataccggaat taaagtcacc gttgagcatc cggataaact ggaagagaaa ttcccacagg 240 ttgcggcaac tggcgatggc cctgacatta tcttctgggc acacgaccgc tttggtggct 300 acgctcaatc tggcctgttg gctgaaatca ccccggacaa agcgttccag gacaagctgt 360 atccgtttac ctgggatgcc gtacgttaca acggcaagct gattgcttac ccgatcgctg 420 ttgaagcgtt atcgctgatt tataacaaag atctgctgcc gaacccgcca aaaacctggg 480 aagagatccc ggcgctggat aaagaactga aagcgaaagg taagagcgcg ctgatgttca 540 acctgcaaga accgtacttc acctggccgc tgattgctgc tgacgggggt tatgcgttca 600 agtatgaaaa cggcaagtac gacattaaag acgtgggcgt ggataacgct ggcgcgaaag 660 cgggtctgac cttcctggtt gacctgatta aaaacaaaca catgaatgca gacaccgatt 720 actccatcgc agaagctgcc tttaataaag gcgaaacagc gatgaccatc aacggcccgt 780 gggcatggtc caacatcgac accagcaaag tgaattatgg tgtaacggta ctgccgacct 840 tcaagggtca accatccaaa ccgttcgttg gcgtgctgag cgcaggtatt aacgccgcca 900 gtccgaacaa agagctggcg aaagagttcc tcgaaaacta tctgctgact gatgaaggtc 960 tggaagcggt taataaagac aaaccgctgg gtgccgtagc gctgaagtct tacgaggaag 1020 agttggcgaa agatccacgt attgccgcca ccatggaaaa cgcccagtcc gctttctggt 1080 atgccgtgcg tatcgaagcc cgcctgcagg cctcggtcga cgccgaatct agaagcgata 1140 aaattattca cctgactgac gacagttttg acacggatgt actcaaagcg gacggggcga 1200 tcctcgtcga tttctgggca gagtggtgcg gtccgtgcaa aatgatcgcc ccgattctgg 1260 atgaaatcgc tgacgaatat cagggcaaac tgaccgttgc aaaactgaac atcgatcaaa 1320 accctggcac tgcgccgaaa tatggcatcc gtggtatccc gactctgctg ctgttcaaaa 1380 acggtgaagt ggcggcaacc aaagtgggtg cactgtctaa aggtcagttg aaagagaacc 1440 tggcggatta taaagatgac gatgacaaat aataag 14762581476DNAArtificial SequenceGene encoding a fusion protein 258 aggaggttct gcatatgaaa ataaaaacag gtgcacgcat cctcgcatta tccgcattaa 60 cgacgatgat gttttccgcc tcggctctcg ccaaaatcga agaaggtaaa ctggtaatct 120 ggattaacgg cgataaaggc tataacggtc tcgctgaagt cggtaagaaa ttcgagaaag 180 ataccggaat taaagtcacc gttgagcatc cggataaact ggaagagaaa ttcccacagg 240 ttgcggcaac tggcgatggc cctgacatta tcttctgggc acacgaccgc tttggtggct 300 acgctcaatc tggcctgttg gctgaaatca ccccggacaa agcgttccag gacaagctgt 360 atccgtttac ctgggatgcc gtacgttaca acggcaagct gattgcttac ccgatcgctg 420 ttgaagcgtt atcgctgatt tataacaaag atctgctgcc gaacccgcca aaaacctggg 480 aagagatccc ggcgctggat aaagaactga aagcgaaagg taagagcgcg ctgatgttca 540 acctgcaaga accgtacttc acctggccgc tgattgctgc tgacgggggt tatgcgttca 600 agtatgaaaa cggcaagtac gacattaaag acgtgggcgt ggataacgct ggcgcgaaag 660 cgggtctgac cttcctggtt gacctgatta aaaacaaaca catgaatgca gacaccgatt 720 actccatcgc agaagctgcc tttaataaag gcgaaacagc gatgaccatc aacggcccgt 780 gggcatggtc caacatcgac accagcaaag tgaattatgg tgtaacggta ctgccgacct 840 tcaagggtca accatccaaa ccgttcgttg gcgtgctgag cgcaggtatt aacgccgcca 900 gtccgaacaa agagctggcg aaagagttcc tcgaaaacta tctgctgact gatgaaggtc 960 tggaagcggt taataaagac aaaccgctgg gtgccgtagc gctgaagtct tacgaggaag 1020 agttggcgaa agatccacgt attgccgcca ccatggaaaa cgcccagtcc gctttctggt 1080 atgccgtgcg tatcgaagcc cgcctgcagg cctcggtcga cgccgaatct agaagcgata 1140 aaattattca cctgactgac gacagttttg acacggatgt actcaaagcg gacggggcga 1200 tcctcgtcga tttctgggca gagtggtgcg gtccgtgcaa aatgatcgcc ccgattctgg 1260 atgaaatcgc tgacgaatat cagggcaaac tgaccgttgc aaaactgaac atcgatcaaa 1320 accctggcac tgcgccgaaa tatggcatcc gtggtatccc gactctgctg ctgttcaaaa 1380 acggtgaagt ggcggcaacc aaagtgggtg cactgtctaa aggtcagttg aaagagaacc 1440 tggcggatta taaagatgac gatgacaaat aataag 1476

Claims (18)

What is claimed:

1. A method for making minicells, comprising

(a) culturing a minicell-producing parent cell, wherein said parent cell comprises an expression construct, wherein said expression construct comprises a gene operably linked to expression sequences that are inducible and/or repressible, and wherein induction or repression of said gene causes or enhances the production of minicells; and

(b) separating said minicells from said parent cell, thereby generating a composition comprising minicells,

wherein an inducer or repressor is present within said parent cells during one or more steps and/or between two or more steps of said method.

2. The method ofclaim 1, further comprising

(c) purifying said minicells from said composition.

3. The method ofclaim 1, wherein said minicell is selected from the group consisting of a eubacterial minicell, a poroplast, a spheroplast and a protoplast.

4. The method ofclaim 1, wherein said gene expresses a gene product that is a factor that is involved in or modulates DNA replication, cellular division, cellular partitioning, septation, transcription, translation, or protein folding.

5. The method ofclaim 1, wherein said minicells are separated from said parent cells by a process selected from the group consisting of centrifugation, ultracentrifugation, density gradation, immunoaffinity and immunoprecipitation.

6. The method ofclaim 2, wherein said minicell is a poroplast, said method further comprising

(d) treating said minicells with an agent, or incubating said minicells under a set of conditions, that degrades the outer membrane of said minicell.

7. The method ofclaim 6, wherein said outer membrane is degraded by treatment with an agent selected from the group consisting of EDTA, EGTA, lactic acid, citric acid, gluconic acid, tartaric acid, polyethyleneimine, polycationic peptides, cationic leukocyte peptides, aminoglycosides, aminoglycosides, protamine, insect cecropins, reptilian magainins, polymers of basic amino acids, polymixin B, chloroform, nitrilotriacetic acid and sodium hexametaphosphate and/or by exposure to conditions selected from the group consisting of osmotic shock and insonation.

8. The method ofclaim 6, further comprising removing one or more contaminants from said composition.

9. The method ofclaim 8, wherein said contaminant is LPS or peptidoglycan.

10. The method ofclaim 9, wherein said LPS is removed by contacting said composition to an agent that binds or degrades LPS.

11. The method ofclaim 1, wherein said minicell-producing parent cell comprises a mutation in a gene required for lipopolysaccharide synthesis.

12. The method ofclaim 2, wherein said minicell is a spheroplast, said method further comprising

(d) treating said minicells with an agent, or incubating said minicells under a set of conditions, that disrupts or degrades the outer membrane; and

(e) treating said minicells with an agent, or incubating said minicells under a set of conditions, that disrupts or degrades the cell wall.

13. The method ofclaim 12, wherein said agent that disrupts or degrades the cell wall is a lysozyme, and said set of conditions that disrupts or degrades the cell wall is incubation in a hypertonic solution.

14. The method ofclaim 2, wherein said minicell is a protoplast, said method further comprising

(d) treating said minicells with an agent, or incubating said minicells under a set of conditions, that disrupt or degrade the outer membrane;

(e) treating said minicells with an agent, or incubating said minicells under a set of conditions, that disrupts or degrades the cell wall, in order to generate a composition that comprises protoplasts; and

(f) purifying protoplasts from said composition.

15. The method ofclaim 2, further comprising preparing a denuded minicell from said minicell.

16. The method ofclaim 2, further comprising covalently or non-covalently linking one or more components of said minicell to a conjugated moiety.

17. A method of preparing a L-form minicell comprising:

(a) culturing an L-form eubacterium, wherein said eubacterium comprises one or more of the following:

(i) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of said gene regulates the copy number of an episomal expression construct;

(ii) a mutation in an endogenous gene, wherein said mutation regulates the copy number of an episomal expression construct.

(iii) an expression element that comprises a gene operably linked to expression sequences that are inducible and/or repressible, wherein induction or repression of said gene causes or enhances the production of minicells; and

(iv) a mutation in an endogenous gene, wherein said mutation causes or enhances minicell production.

(b) culturing said L-form minicell-producing parent cell in media under conditions wherein minicells are produced; and

(c) separating said minicells from said parent cell, thereby generating a composition comprising L-form minicells,

wherein an inducer or repressor is present within said minicells during one or more steps and/or between two or more steps of said method.

18. The method ofclaim 17, further comprising

(d) purifying said L-form minicells from said composition.

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