US20170151281A1 - Chimeric antigen receptor dendritic cell (car-dc) for treatment of cancer - Google Patents

Abstract

The current invention provides monocytic cells transfected with chimeric antigen receptor (CAR) to selectively home to tumors and upon homing differentiate into dendritic cells capable of activating immunity which is inhibitory to said tumor. In one embodiment of the invention, monocytic cells are transfected with a construct encoding an antigen binding domain, a transcellular or structural domain, and an intracellular signaling domain. In one specific aspect of the invention, the antigen binding domain interacts with sufficient affinity to a tumor antigen, capable of triggering said intracellular domain to induce an activation signal to induce monocyte differentiation into DC.

Description

CROSS-REFERENCE TO RELATED APPLICATION
• This application claims the benefit of U.S. Provisional Application No. 62/118,027 filed on Feb. 19, 2015, the contents of which are incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
• The present disclosure generally relates to the fields of genetics, immunology and medicine. The invention pertains to the field of immunotherapy, more specifically the invention pertains to the utilization of monocytes that have been manipulated to home to tumor cells and upon binding to tumor antigens differentiating into monocytes with cytotoxic properties to tumors, or dendritic cells.
BACKGROUND OF THE INVENTION
• The immune system possesses the power to cure cancers based on published reports of immunologically mediated spontaneous regressions, which have been document in colon, lung, melanoma, liver, breast. Intriguingly, spontaneous regression clinically, as well as in an animal model of spontaneous regression, seems to be associated primarily with stimulation of the innate immune system, comprising of macrophages, NK cells, NKT cells and neutrophils. Despite the original promising of immunotherapy, which will be mentioned, the field has focused on the adaptive immune response, specifically stimulation of T and B cells, and only recently has interest re-ignited in the innate immune system.
• The use of the immune system to treat cancer is theoretically appealing due to the possibility of low toxicity, immunological memory, and ability to attack metastatic disease. Early studies suggested that vaccination to tumor antigens and tumors themselves may be possible. Specifically, Prehn back in 1957, obtained murine tumors and exposed them to irradiation to increase immunogenicity. When these tumors were implanted into animals they were rejected. Subsequent administration of the original tumors resulted in rejection of the tumors, thus suggesting that tumor specific antigens exist, which can stimulate immunity, especially subsequent to addition of a cellular stress such as irradiation. Twenty years later, using the same system it was demonstrated that cytotoxic T cells infiltrated the tumors that were implanted after rejection of the radiation induced tumors, thus demonstrating conclusively that rejection was immunologically mediated, despite the fact that the tumors were syngeneic. In humans, one of the original observations of immunological response to neoplasia was in patients with paraneoplastic disease in which immune response to breast cancer antigens results in a multiple sclerosis-like disease caused by cross reactive immunity to neural antigens that are found on the breast cancer. Specific identification of tumor antigens on a molecular basis led to the discovery that some of the antigens are either self-proteins aberrantly expressed, or mutations of self proteins.
• Originally observations were made in patients bearing metastatic melanomas, and then subsequently in other tumors, that the tumors are infiltrated with various immunological components. These tumor infiltrating lymphocytes (TILs), contain populations of cells and individual clones that demonstrate tumor specificity; they lyse autologous tumor cells but not natural killer targets, allogeneic tumor cells, or autologous fibroblasts.
• By isolating and expanding TILs in vitro, and then molecularly identifying what they are responding to, a variety of the well-known tumor agents have been discovered such as MAGE-1, and MAGE-3, GAGE-1, MART-1, Melan-A, gp100, gp75 (TRP-2), tyrosinase, NY-ESO-1, mutated p16, and beta catenin. It is interesting that in the case of some antigens, such as gp75, the peptide that elicits tumor rejection results from translation of an alternative open reading frame of the same gene. Thus, the gp75 gene encodes two completely different polypeptides, gp75 as an antigen recognized by immunoglobulin G antibodies in sera from a patient with cancer, and a 24-amino acid product as a tumor rejection antigen recognized by T cells. Peptides used for immunization generally are 8-9 amino acids which have been demonstrated to be displayed in association with class I MHC molecules for recognition by T cells, and tumor cells have been shown to express these naturally processed epitopes.
• Despite the intellectual appeal of peptide based cancer vaccines, the response rate has been disappointingly low. According to a review by Steven Rosenberg's group at the NIH, the rate of objective response out of 440 patients treated at his institute was a dismal 2.6%.
• The ability to make a universal yet versatile system to generate T cells that are capable of recognizing various types of cancers has important clinical implications for the use of T cell-based therapies, this concept was approach initially by Rosenberg's group in the ex vivo expansion of tumor infiltrating lymphocytes. One current strategy incorporates the use of genetic engineering to express a chimeric antigen receptor (CAR) on T cells. The extracellular domain of a typical CAR consists of the V_Hand V_Ldomains—single-chain fragment variable (scFv)—from the antigen binding sites of a monoclonal antibody. The scFv is linked to a flexible transmembrane domain followed by a tyrosine-based activation motif such as that from CD3ζ. The so-called second and third generation CARs include additional activation domains from co-stimulatory molecules such as CD28 and CD137 (41BB) which serve to enhance T cell survival and proliferation. CAR T cells offer the opportunity to seek out and destroy cancer cells by recognizing tumor-associated antigens (TAA) expressed on their surface. As such, the recognition of a tumor cells occurs via an MHC-independent mechanism.
• Various preclinical and early-phase clinical trials highlight the efficacy of CAR T cells to treat cancer patients with solid tumors and hematopoietic malignancies. Despite of the promise that CAR T cells might have in treating cancer patients there are several limitations to the generalized clinical application of CAR T cells. First, since no single tumor antigen is universally expressed by all cancer types, scFv in CAR needs to be constructed for each tumor antigen to be targeted. Second, the financial cost and labor-intensive tasks associated with identifying and engineering scFvs against a variety of tumor antigens poses a major challenge. Third, tumor antigens targeted by CAR could be down-regulated or mutated in response to treatment resulting in tumor evasion. Since current CAR T cells recognize only one target antigen, such changes in tumors negate the therapeutic effects. Therefore, the generation of CAR T cells capable of recognizing multiple tumor antigens is highly desired. Finally, CAR T cells react with target antigen weakly expressed on non-tumor cells, potentially causing severe adverse effects. To avoid such “on-target off-tumor” reaction, use of scFvs with higher specificity to tumor antigen is required. And although ongoing studies are focused on generating methods to shut off CAR T cells in vivo this system has yet to be developed and might pose additional inherent challenges.
• The current patent seeks to apply chimeric antigen receptor technology to activation of monocytes, which naturally home into tumors, to differentiated intratumorally said monocytes into dendritic cells which are capable of antigen presentation, as well as direct killing of tumors.
DETAILED DESCRIPTION OF THE INVENTION
• Chimeric antigen receptor (CAR) cellular therapeutics have revolutionized the treatment of B cell malignancies achieving stunning success rates. Unfortunately, solid tumors have yet to benefit from this treatment. Additionally, patients treated with CAR-T cells lack B cells for the rest of their lives, as well as having the possibility of tumor lysis syndrome. This is in part due to the permanence of the CAR-T cells in the patients after treatment. The current invention applies the use of CAR technology to monocytes with the purpose of inducing differentiation to dendritic cells (DC) subsequent to contact with tumor antigens. Given that monocytes have a fixed mitotic index, fears of permanent manipulation of the host are diminished.
• “Treating a cancer”, “inhibiting cancer”, “reducing cancer growth” refers to inhibiting or preventing oncogenic activity of cancer cells. Oncogenic activity can comprise inhibiting migration, invasion, drug resistance, cell survival, anchorage-independent growth, non-responsiveness to cell death signals, angiogenesis, or combinations thereof of the cancer cells.
• The terms “cancer”, “cancer cell”, “tumor”, and “tumor cell” are used interchangeably herein and refer generally to a group of diseases characterized by uncontrolled, abnormal growth of cells (e.g., a neoplasia). In some forms of cancer, the cancer cells can spread locally or through the bloodstream and lymphatic system to other parts of the body (“metastatic cancer”).
• “Ex vivo activated lymphocytes”, “lymphocytes with enhanced antitumor activity” and “dendritic cell cytokine induced killers” are terms used interchangeably to refer to composition of cells that have been activated ex vivo and subsequently reintroduced within the context of the current invention. Although the word “lymphocyte” is used, this also includes heterogenous cells that have been expanded during the ex vivo culturing process including dendritic cells, NKT cells, gamma delta T cells, and various other innate and adaptive immune cells.
• As used herein, “cancer” refers to all types of cancer or neoplasm or malignant tumors found in animals, including leukemias, carcinomas and sarcomas. Examples of cancers are cancer of the brain, melanoma, bladder, breast, cervix, colon, head and neck, kidney, lung, non-small cell lung, mesothelioma, ovary, prostate, sarcoma, stomach, uterus and Medulloblastoma.
• The term “leukemia” is meant broadly progressive, malignant diseases of the hematopoietic organs/systems and is generally characterized by a distorted proliferation and development of leukocytes and their precursors in the blood and bone marrow. Leukemia diseases include, for example, acute nonlymphocytic leukemia, chronic lymphocytic leukemia, acute granulocytic leukemia, chronic granulocytic leukemia, acute promyelocytic leukemia, adult T-cell leukemia, aleukemic leukemia, a leukocythemic leukemia, basophilic leukemia, blast cell leukemia, bovine leukemia, chronic myelocytic leukemia, leukemia cutis, embryonal leukemia, eosinophilic leukemia, Gross' leukemia, Rieder cell leukemia, Schilling's leukemia, stem cell leukemia, subleukemic leukemia, undifferentiated cell leukemia, hairy-cell leukemia, hemoblastic leukemia, hemocytoblastic leukemia, histiocytic leukemia, stem cell leukemia, acute monocytic leukemia, leukopenic leukemia, lymphatic leukemia, lymphoblastic leukemia, lymphocytic leukemia, lymphogenous leukemia, lymphoid leukemia, lymphosarcoma cell leukemia, mast cell leukemia, megakaryocytic leukemia, micromyeloblastic leukemia, monocytic leukemia, myeloblastic leukemia, myelocytic leukemia, myeloid granulocytic leukemia, myelomonocytic leukemia, Naegeli leukemia, plasma cell leukemia, plasmacytic leukemia, and promyelocytic leukemi.
• The term “carcinoma” refers to a malignant new growth made up of epithelial cells tending to infiltrate the surrounding tissues, and/or resist physiological and non-physiological cell death signals and give rise to metastases. Exemplary carcinomas include, for example, acinar carcinoma, acinous carcinoma, adenocystic carcinoma, adenoid cystic carcinoma, carcinoma adenomatosum, carcinoma of adrenal cortex, alveolar carcinoma, alveolar cell carcinoma, basal cell carcinoma, carcinoma basocellulare, basaloid carcinoma, basosquamous cell carcinoma, bronchioalveolar carcinoma, bronchiolar carcinoma, bronchogenic carcinoma, cerebriform carcinoma, cholangiocellular carcinoma, chorionic carcinoma, colloid carcinoma, comedo carcinoma, corpus carcinoma, cribriform carcinoma, carcinoma en cuirasse, carcinomacutaneum, cylindrical carcinoma, cylindrical cell carcinoma, duct carcinoma, carcinoma durum, embryonal carcinoma, encephaloid carcinoma, epiennoid carcinoma, carcinoma epitheliale adenoides, exophytic carcinoma, carcinoma ex ulcere, carcinoma fibrosum, gelatiniform carcinoma, gelatinous carcinoma, giant cell carcinoma, signet-ring cell carcinoma, carcinoma simplex, small-cell carcinoma, solanoid carcinoma, spheroidal cell carcinoma, spindle cell carcinoma, carcinoma spongiosum, squamous carcinoma, squamous cell carcinoma, string carcinoma, carcinoma telangiectaticum, carcinoma telangiectodes, transitional cell carcinoma, carcinomatuberosum, tuberous carcinoma, verrmcous carcinoma, carcinomavillosum, carcinoma gigantocellulare, glandular carcinoma, granulosa cell carcinoma, hair-matrix carcinoma, hematoid carcinoma, hepatocellular carcinoma, Hurthle cell carcinoma, hyaline carcinoma, hypemephroid carcinoma, infantile embryonal carcinoma, carcinoma in situ, intraepidermal carcinoma, intraepithelial carcinoma, Krompecher's carcinoma, Kulchitzky-cell carcinoma, large-cell carcinoma, lenticular carcinoma, carcinoma lenticulare, lipomatous carcinoma, lymphoepithelial carcinoma, carcinoma medullare, medullary carcinoma, melanotic carcinoma, carcinoma molle, mucinous carcinoma, carcinoma muciparum, carcinoma mucocellulare, mucoepidermoid carcinoma, carcinomamucosum, mucous carcinoma, carcinoma myxomatodes, naspharyngeal carcinoma, oat cell carcinoma, carcinoma ossificans, osteoid carcinoma, papillary carcinoma, periportal carcinoma, preinvasive carcinoma, prickle cell carcinoma, pultaceous carcinoma, renal cell carcinoma of kidney, reserve cell carcinoma, carcinoma sarcomatodes, schneiderian carcinoma, scirrhous carcinoma, and carcinoma scroti.
• The term “sarcoma” generally refers to a tumor which is made up of a substance like the embryonic connective tissue and is generally composed of closely packed cells embedded in a fibrillar, heterogeneous, or homogeneous substance. Sarcomas include, chondrosarcoma, fibrosarcoma, lymphosarcoma, melanosarcoma, myxosarcoma, osteosarcoma, endometrial sarcoma, stromal sarcoma, Ewing's sarcoma, fascial sarcoma, fibroblastic sarcoma, giant cell sarcoma, Abemethy's sarcoma, adipose sarcoma, liposarcoma, alveolar soft part sarcoma, ameloblastic sarcoma, botryoid sarcoma, chloroma sarcoma, chorio carcinoma, embryonal sarcoma, Wilms' tumor sarcoma, granulocytic sarcoma, Hodgkin's sarcoma, idiopathic multiple pigmented hemorrhagic sarcoma, immunoblastic sarcoma of B cells, lymphoma, immunoblastic sarcoma of T-cells, Jensen's sarcoma, Kaposi's sarcoma, Kupffer cell sarcoma, angiosarcoma, leukosarcoma, malignant mesenchymoma sarcoma, parosteal sarcoma, reticulocytic sarcoma, Rous sarcoma, serocystic sarcoma, synovial sarcoma, and telangiectaltic sarcoma. Additional exemplary neoplasias include, for example, Hodgkin's Disease, Non-Hodgkin's Lymphoma, multiple myeloma, neuroblastoma, breast cancer, ovarian cancer, lung cancer, rhabdomyosarcoma, primary thrombocytosis, primary macroglobulinemia, small-cell lung tumors, primary brain tumors, stomach cancer, colon cancer, malignant pancreatic insulanoma, malignant carcinoid, premalignant skin lesions, testicular cancer, lymphomas, thyroid cancer, neuroblastoma, esophageal cancer, genitourinary tract cancer, malignant hypercalcemia, cervical cancer, endometrial cancer, and adrenal cortical cancer.
• In some particular embodiments of the invention, the cancer treated is a melanoma. The term “melanoma” is taken to mean a tumor arising from the melanocytic system of the skin and other organs. Melanomas include, for example, Harding-Passey melanoma, juvenile melanoma, lentigo maligna melanoma, malignant melanoma, acral-lentiginous melanoma, amelanotic melanoma, benign juvenile melanoma, Cloudman's melanoma, S91 melanoma, nodular melanoma subungal melanoma, and superficial spreading melanoma.
• The term “polypeptide” is used interchangeably with “peptide”, “altered peptide ligand”, and “flourocarbonated peptides.”
• The term “pharmaceutically acceptable carrier” includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. Except insofar as any conventional media or agent is incompatible with the active compound, use thereof in the therapeutic compositions is contemplated. Supplementary active compounds can also be incorporated into the compositions.
• The term “T cell” is also referred to as T lymphocyte, and means a cell derived from thymus among lymphocytes involved in an immune response. The T cell includes any of a CD8-positive T cell (cytotoxic T cell: CTL), a CD4-positive T cell (helper T cell), a suppressor T cell, a regulatory T cell such as a controlling T cell, an effector cell, a naive T cell, a memory T cell, an αβT cell expressing TCR α and β chains, and a γδ T cell expressing TCR γ and δ chains. The T cell includes a precursor cell of a T cell in which differentiation into a T cell is directed.
• Examples of “cell populations containing T cells” include, in addition to body fluids such as blood (peripheral blood, umbilical blood etc.) and bone marrow fluids, cell populations containing peripheral blood mononuclear cells (PBMC), hematopoietic cells, hematopoietic stem cells, umbilical blood mononuclear cells etc., which have been collected, isolated, purified or induced from the body fluids. Further, a variety of cell populations containing T cells and derived from hematopoietic cells can be used in the present invention. These cells may have been activated by cytokine such as IL-2 in vivo or ex vivo. As these cells, any of cells collected from a living body, or cells obtained via ex vivo culture, for example, a T cell population obtained by the method of the present invention as it is, or obtained by freeze preservation, can be used.
• The term “antibody” is meant to include both intact molecules as well as fragments thereof that include the antigen-binding site. Whole antibody structure is often given as H₂L₂and refers to the fact that antibodies commonly comprise 2 light (L) amino acid chains and 2 heavy (H) amino acid chains. Both chains have regions capable of interacting with a structurally complementary antigenic target. The regions interacting with the target are referred to as “variable” or “V” regions and are characterized by differences in amino acid sequence from antibodies of different antigenic specificity. The variable regions of either H or L chains contains the amino acid sequences capable of specifically binding to antigenic targets. Within these sequences are smaller sequences dubbed “hypervariable” because of their extreme variability between antibodies of differing specificity. Such hypervariable regions are also referred to as “complementarity determining regions” or “CDR” regions. These CDR regions account for the basic specificity of the antibody for a particular antigenic determinant structure. The CDRs represent non-contiguous stretches of amino acids within the variable regions but, regardless of species, the positional locations of these critical amino acid sequences within the variable heavy and light chain regions have been found to have similar locations within the amino acid sequences of the variable chains. The variable heavy and light chains of all antibodies each have 3 CDR regions, each non-contiguous with the others (termed L1, L2, L3, H1, H2, H3) for the respective light (L) and heavy (H) chains. The antibodies disclosed according to the invention may also be wholly synthetic, wherein the polypeptide chains of the antibodies are synthesized and, possibly, optimized for binding to the polypeptides disclosed herein as being receptors. Such antibodies may be chimeric or humanized antibodies and may be fully tetrameric in structure, or may be dimeric and comprise only a single heavy and a single light chain.
• The term “effective amount” or “therapeutically effective amount” means a dosage sufficient to treat, inhibit, or alleviate one or more symptoms of a disease state being treated or to otherwise provide a desired pharmacologic and/or physiologic effect, especially enhancing T cell response to a selected antigen. The precise dosage will vary according to a variety of factors such as subject-dependent variables (e.g., age, immune system health, etc.), the disease, and the treatment being administered.
• The terms “individual”, “host”, “subject”, and “patient” are used interchangeably herein, and refer to a mammal, including, but not limited to, primates, for example, human beings, as well as rodents, such as mice and rats, and other laboratory animals.
• As used herein, the term “treatment regimen” refers to a treatment of a disease or a method for achieving a desired physiological change, such as increased or decreased response of the immune system to an antigen or immunogen, such as an increase or decrease in the number or activity of one or more cells, or cell types, that are involved in such response, wherein said treatment or method comprises administering to an animal, such as a mammal, especially a human being, a sufficient amount of two or more chemical agents or components of said regimen to effectively treat a disease or to produce said physiological change, wherein said chemical agents or components are administered together, such as part of the same composition, or administered separately and independently at the same time or at different times (i.e., administration of each agent or component is separated by a finite period of time from one or more of the agents or components) and where administration of said one or more agents or components achieves a result greater than that of any of said agents or components when administered alone or in isolation.
• The term “anergy” and “unresponsiveness” includes unresponsiveness to an immune cell to stimulation, for example, stimulation by an activation receptor or cytokine. The anergy may occur due to, for example, exposure to an immune suppressor or exposure to an antigen in a high dose. Such anergy is generally antigen-specific, and continues even after completion of exposure to a tolerized antigen. For example, the anergy in a T cell and/or NK cell is characterized by failure of production of cytokine, for example, interleukin (IL)-2. The T cell anergy and/or NK cell anergy occurs in part when a first signal (signal via TCR or CD-3) is received in the absence of a second signal (costimulatory signal) upon exposure of a T cell and/or NK cell to an antigen.
• The term “enhanced function of a T cell”, “enhanced cytotoxicity” and “augmented activity” means that the effector function of the T cell and/or NK cell is improved. The enhanced function of the T cell and/or NK cell, which does not limit the present invention, includes an improvement in the proliferation rate of the T cell and/or NK cell, an increase in the production amount of cytokine, or an improvement in cytotoxity. Further, the enhanced function of the T cell and/or NK cell includes cancellation and suppression of tolerance of the T cell and/or NK cell in the suppressed state such as the anergy (unresponsive) state, or the rest state, that is, transfer of the T cell and/or NK cell from the suppressed state into the state where the T cell and/or NK cell responds to stimulation from the outside.
• The term “expression” means generation of mRNA by transcription from nucleic acids such as genes, polynucleotides, and oligonucleotides, or generation of a protein or a polypeptide by transcription from mRNA. Expression may be detected by means including RT-PCR, Northern Blot, or in situ hybridization.
• “Suppression of expression” refers to a decrease of a transcription product or a translation product in a significant amount as compared with the case of no suppression. The suppression of expression herein shows, for example, a decrease of a transcription product or a translation product in an amount of 30% or more, preferably 50% or more, more preferably 70% or more, and further preferably 90% or more.
• In one embodiment of the invention the CAR-DC are antigen-loaded and co-cultured with T-lymphocytes to produce antigen-specific T-cells. As used herein, the term “antigen-specific T-cells” refers to T-cells that proliferate upon exposure to the antigen-loaded APCs of the present invention, as well as to develop the ability to attack cells having the specific antigen on their surfaces. Such T-cells, e.g., cytotoxic T-cells, lyse target cells by a number of methods, e.g., releasing toxic enzymes such as granzymes and perforin onto the surface of the target cells or by effecting the entrance of these lytic enzymes into the target cell interior. Generally, cytotoxic T-cells express CD8 on their cell surface. T-cells that express the CD4 antigen CD4, commonly known as “helper” T-cells, can also help promote specific cytotoxic activity and may also be activated by the antigen-loaded APCs of the present invention. In certain embodiments, the cancer cells, the APCs and even the T-cells can be derived from the same donor whose MNC yielded the DC, which can be the patient or an HLA—or obtained from the individual patient that is going to be treated. Alternatively, the cancer cells, the APCs and/or the T-cells can be allogeneic.
• The invention provides means of inducing an anti-cancer response in a mammal, comprising the steps of initially “priming” the mammal by administering an agent that causes local accumulation of CAR-DC. Subsequently, a tumor antigen is administered in the local area where said agents causing accumulation of antigen presenting cells is administered. A time period is allowed to pass to allow for said antigen presenting cells to traffic to the lymph nodes. Subsequently a maturation signal, or a plurality of maturation signals are administered to enhance the ability of said antigen presenting cell to activate adaptive immunity. In some embodiments of the invention activators of adaptive immunity are concurrently given, as well as inhibitors of the tumor derived inhibitors are administered to derepress the immune system.
• In one embodiment priming of the patient is achieved by administration of GM-CSF subcutaneously in the area in which antigen is to be injected. Various scenarios are known in the art for administration of GM-CSF prior to administration, or concurrently with administration of antigen. The practitioner of the invention is referred to the following publications for dosage regimens of GM-CSF and also of peptide antigens.
• Subsequent to priming, the invention calls for administration of tumor antigen. Various tumor antigens may be utilized, in one preferred embodiment, lysed tumor cells from the same patient area utilized. Means for generation of lyzed tumor cells are well known in the art and described in the following references. One example method for generation of tumor lysate involves obtaining frozen autologous samples which are placed in hanks buffered saline solution (HBSS) and gentamycin 50 μg/ml followed by homogenization by a glass homogenizer. After repeated freezing and thawing, particle-containing samples are selected and frozen in aliquots after radiation with 25 kGy. Quality assessment for sterility and endotoxin content is performed before freezing. Cell lysates are subsequently administered into the patient in a preferred manner subcutaneously at the local areas where DC priming was initiated. After 12-72 hours, the patient is subsequently administered with an agent capable of inducing maturation of DC. Agents useful for the practice of the invention, in a preferred embodiment include BCG and HMGB1 peptide. Other useful agents include: a) histone DNA; b) imiqimod; c) beta-glucan; d) hsp65; e) hsp90; f) HMGB-1; g) lipopolysaccharide; h) Pam3CSK4; i) Poly I: Poly C; j) Flagellin; k) MALP-2; l) Imidazoquinoline; m) Resiquimod; n) CpG oligonucleotides; o) zymosan; p) peptidoglycan; q) lipoteichoic acid; r) lipoprotein from gram-positive bacteria; s) lipoarabinomannan from mycobacteria; t) Polyadenylic-polyuridylic acid; u) monophosphoryl lipid A; v) single stranded RNA; w) double stranded RNA; x) 852A; y) rintatolimod; z) Gardiquimod; and aa) lipopolysaccharide peptides. The procedure is performed in a preferred embodiment with the administration of IDO silencing siRNA or shRNA containing the effector sequences a) UUAUAAUGACUGGAUGUUC; b) GUCUGGUGUAUGAAGGGUU; c) CUCCUAUUUUGGUUUAUGC and d) GCAGCGUCUUUCAGUGCUU. siRNA or shRNA may be administered through various modalities including biodegradable matrices, pressure gradients or viral transfect. In another embodiment, autologous dendritic cells are generated and IDO is silenced, prior to, concurrent with or subsequent to silencing, said dendritic cells are pulsed with tumor antigen and administered systemically.
• In one embodiment of the invention mature DC are modified with CAR transfection prior to administration. Culture of dendritic cells is well known in the art, for example, U.S. Pat. No. 6,936,468, issued to Robbins, et al., for the use of tolerogenic dendritic cells for enhancing tolerogenicity in a host and methods for making the same. Although the current invention aims to reduce tolerogenesis, the essential means of dendritic cell generation are disclosed in the patent. U.S. Pat. No. 6,734,014, issued to Hwu, et al., for methods and compositions for transforming dendritic cells and activating T cells. Briefly, recombinant dendritic cells are made by transforming a stem cell and differentiating the stem cell into a dendritic cell. The resulting dendritic cell is said to be an antigen presenting cell which activates T cells against MHC class I-antigen targets. Antigens for use in dendritic cell loading are taught in, e.g., U.S. Pat. No. 6,602,709, issued to Albert, et al. This patent teaches methods for use of apoptotic cells to deliver antigen to dendritic cells for induction or tolerization of T cells. The methods and compositions are said to be useful for delivering antigens to dendritic cells that are useful for inducing antigen-specific cytotoxic T lymphocytes and T helper cells. The disclosure includes assays for evaluating the activity of cytotoxic T lymphocytes. The antigens targeted to dendritic cells are apoptotic cells that may also be modified to express non-native antigens for presentation to the dendritic cells. The dendritic cells are said to be primed by the apoptotic cells (and fragments thereof) capable of processing and presenting the processed antigen and inducing cytotoxic T lymphocyte activity or may also be used in vaccine therapies. U.S. Pat. No. 6,455,299, issued to Steinman, et al., teaches methods of use for viral vectors to deliver antigen to dendritic cells. Methods and compositions are said to be useful for delivering antigens to dendritic cells, which are then useful for inducing T antigen specific cytotoxic T lymphocytes. The disclosure provides assays for evaluating the activity of cytotoxic T lymphocytes. Antigens are provided to dendritic cells using a viral vector such as influenza virus that may be modified to express non-native antigens for presentation to the dendritic cells. The dendritic cells are infected with the vector and are said to be capable of presenting the antigen and inducing cytotoxic T lymphocyte activity or may also be used as vaccines.
• Immune cells for use in the practice of the invention include DCs, the presence of which may be checked in the previously described method, are preferably selected from myeloid cells (such as monocytic cells and macrophages) expressing langerin, MHC (major histocompatibility complex) class II, CCR2 (chemokine (C—C motif) receptor 2), CX3CR1 and/or Gr1 molecules in mice; myeloid cells expressing CD14, CD16, HLA dR (human leukocyte antigen disease resistance) molecule, langerin, CCR2 and/or CX3CR1 in humans; dendritic cells expressing CD11c, MHC class II molecules, and/or CCR7 molecules; and IL-1β producing dendritic cells. CD8 T cells, the presence of which may be checked in the previously described method, are preferably selected from CD3+, CD4+ and/or CD8+T lymphocytes, FOXP3 (forkhead box P3) T lymphocytes, Granzyme B/TIA (Tcell-restricted intracellular antigen) T lymphocytes, and Tc1 cells (IFN-.gamma. producing CD8+T lymphocytes). Immune cells expressing a protein that binds calreticulin, such immune cells may be selected from cells expressing at least one of the following proteins: LRP1 (Low density lipoprotein receptor-related protein 1, CD91), Ca.sup.++-binding proteins such as SCARF1 and SCARF2, MSR1 (Macrophage scavenger receptor 1), SRA, CD59 (protectin), CD207 (langerin), and THSD1 (thrombospondin). There are numerous means known in the art to identify cells expressing various antigens, these include immunochemistry, immunophenotyping, flow cytometry, Elispots assays, classical tetramer staining, and intracellular cytokine stainings.
• Macrophages selectively phagocytose tumor cells, but this process is countered by protective molecules on tumor cells such as CD47, which binds macrophage signal-regulatory protein a to inhibit phagocytosis. Blockade of CD47 on tumor cells leads to phagocytosis by macrophages. In one embodiment of the invention CAR-MSC are administered together with an agent that blocks CD47 activity. It has been demonstrated that activation of TLR signaling pathways in macrophages synergizes with blocking CD47 on tumor cells to enhance tumor phagocytosis. Bruton's tyrosine kinase (Btk) mediates TLR signaling in macrophages. Calreticulin, previously shown to be a protein found on cancer cells that activated macrophage phagocytosis of tumors, is activated in macrophages for secretion and cell-surface exposure by TLR and Btk to target cancer cells for phagocytosis, even if the cancer cells themselves do not express calreticulin. In one embodiment of the invention TLR agonists are administered that stimulate expression of calreticulin and/or enhance macrophage phagocytosis of tumors.
• IL-27 induces macrophage ability to kill tumor cells in vitro and in vivo, as well as altering the tumor promoting M2/myeloid suppressor cells into tumoricidal cells. In one embodiment of the invention addition of IL-27 or compounds capable of activating the IL-27 receptor signaling are administered together with IL-27 to enhance tumor phagocytosis by macrophages.
• Tumor-associated macrophages, deriving from monocytes or migrating into the tumor, are an important constituent of tumor microenvironments, which in many cases modulates tumor growth, tumor angiogenesis, immune suppression, metastasis and chemoresistance. Mechanisms of macrophage promotion of tumor growth include production of EGF, M-CSF, VEGF.
• Macrophage infiltration of tumors is associated with poor prognosis in renal, melanoma, breast, pancreatic, lung, endometrial, bladder, prostate.
• Tumor growth are inhibited when monocytes/macrophages are ablated. There is ample evidence that many anticancer modalities currently used in the clinic have unique and distinct properties that modulate the recruitment, polarization and tumorigenic activities of macrophages in the tumor microenvironments. By manipulating tumor-associated macrophages significant impact on the clinical efficacies of and resistance to these anticancer modalities. Accordingly, in one aspect of the invention, CAR-DC, CAR-monocytes, or CAR-macrophages are utilized to force the tumor microenvironment to stimulate tumor killing and inhibit macrophage or macrophage related cells from promoting tumor growth. Within the context of the invention, the use of drugs targeting tumor-associated macrophages, especially c-Fms kinase inhibitors and humanized antibodies targeting colony-stimulating factor-1 receptor, are envisioned.
• Tumors mediate various effects to reprogram macrophages, these are usually mediated via IL-10 and other cytokines such as VEGF, TGF-beta, and M-CSF, which cause macrophages to lose tumor cytotoxicity and shift into tumor promoting, immune suppressive, angiogenic supporting cells. Related to tumor manipulated monocytes are myeloid derived suppressor cells, which are similar to myeloid progenitor cells, or the previously described “natural suppressor” cell.
• Irradiated tissues induce a TLR-1 reprogramming of macrophages to promote tumor growth and angiogenesis. Macrophage promotion of tumor growth is seen in numerous situations, in one example, treating of tumor bearing animals with BRAF inhibitors results in upregulation of macrophage production of VEGF which accelerates tumor growth. Mechanistically, it is known that tumors produce factors such as GM-CSF which in part stimulate macrophages to produce CCL18, which promotes tumor metastasis. Additionally, the lactic acid microenvironment of the tumor has been shown to promote skewing of macrophages towards at tumor-promoting M2 type. It has been shown that lactic acid produced by tumour cells, as a by-product of aerobic or anaerobic glycolysis, possesses an essential role in inducing the expression of VEGF and the M2-like polarization of tumour-associated macrophages, specifically inducing expression of arginase 1 through a HIF-1alpha dependent pathway. Mechanistically, it is known that lactic acid in tumors is generated in a large part by lactate dehydrogenase-A (LDH-A), which converts pyruvate to lactate. siRNA silencing of LDH-A in Pan02 pancreatic cancer cells that are injected in C57BL/6 mice results in development of smaller tumors than mice injected with wild type, non-silenced Pan02 cells. Associated with the reduced tumor growth were observations of a decrease in the frequency of myeloid-derived suppressor cells (MDSCs) in the spleens of mice carrying LDH-A-silenced tumors. NK cells from LDH-A-depleted tumors had improved cytolytic function. Exogenous lactate administration was shown to increase the frequency of MDSCs generated from mouse bone marrow cells with GM-CSF and IL-6 in vitro. Furthermore lactate pretreatment of NK cells in vitro inhibited cytolytic function of both human and mouse NK cells. This reduction of NK cytotoxic activity was accompanied by lower expression of perforin and granzyme in NK cells. The expression of NKp46 was lower in lactate-treated NK cells. Accordingly, in one embodiment of the invention, depletion of glucose levels using a ketogenic diet to lower lactate production by glycolytic tumors is utilized to augment therapeutic effects of CAR-DC. Utilization of ketogenic diet has been previously described for immune modulation, and cancer therapy. Specific quantification of intratumoral lactate and its manipulation has been described and incorporated by reference. Potentiation of chemotherapeutic and radiotherapeutic effects by ketogenic diets have been reported and techniques are incorporated by reference for use with the current CAR-DC invention. Suppression of tumor growth and activity induced by ketogenic diet may be augmented by addition of hyperbaric oxygen, thus in one embodiment of the invention, the utilization of oxidative therapies, as disclosed in references incorporated, together with ketogenic diet is utilized to augment therapeutic efficacy of CAR-DC.
• Not only has it been well known that monocytes and macrophages infiltrate tumors and appear to support tumor growth through growth factor production and secretion of angiogenic agents, but suggestions have been made that tumors themselves, as part of the epithelial mesenchymal transition may actually differentiate into monocytes in part associated with TGF-beta production. Specifically, a study reported performing gene-profiling analysis of mouse mammary EpRas tumor cells that had been allowed to adopt an epithelial to mesenchymal transition program after long-term treatment with TGF-β1 for 2 weeks. While the treated cells acquired traits of mesenchymal cell differentiation and migration, gene analysis revealed another cluster of induced genes, which was specifically enriched in monocyte-derived macrophages, mast cells, and myeloid dendritic cells, but less in other types of immune cells. Further studies revealed that this monocyte/macrophage gene cluster was enriched in human breast cancer cell lines displaying an EMT or a Basal B profile, and in human breast tumors with EMT and undifferentiated (ER−/PR−) characteristics. The plasticity of tumor cells to potentially monocytic lineages should come as no surprise given that tumor cells have been shown to differentiate directly into pericytes, and endothelial cells/vascular channels.
• Dopamine possesses antiangiogenic effects as well as myeloprotective effects, in one embodiment of the invention addition of dopamine to the CAR-DC treatment is disclosed.
• Vinblastine is a widely used chemotherapeutic agent that has been demonstrated to induce dendritic cell maturation. In one embodiment of the invention CAR-DC are utilized together with vinblastine therapy to induce augmented anticancer activity. Oxiplatin and anthracyclines have been demonstrated to not only directly kill tumor cells but also stimulate T cell immunity against tumor cells. It was demonstrated that these agents induce a rapid and prominent invasion of interleukin (IL)-17-producing γδ (Vγ4(+) and Vγ6(+)) T lymphocytes (γδ T17 cells) that precedes the accumulation of CD8 CTLs within the tumor bed. In T cell receptor δ(−/−) or Vγ4/6(−/−) mice, the therapeutic efficacy of chemotherapy was reduced and furthermore no IL-17 was produced by tumor-infiltrating T cells, and CD8 CTLs did not invade the tumor after treatment. Although γδ Th17 cells could produce both IL-17A and IL-22, the absence of a functional IL-17A-IL-17R pathway significantly reduced tumor-specific T cell responses elicited by tumor cell death, and the efficacy of chemotherapy in four independent transplantable tumor models. The adoptive transfer of γδ T cells to naïve mice restored the efficacy of chemotherapy in IL-17A(−/−) hosts. The anticancer effect of infused γδ T cells was lost when they lacked either IL-1R1 or IL-17A.
• Intratumoral injection of dendritic cells stimulates antitumor immunity in vivo in clinical situations, suggesting that modulating the antigen presenting cell in the tumor microenvironment will induce an antitumor response. Administration of radiotherapy to tumors to induce immunogenic cell death, followed by intratumoral administration of DC has been demonstrated to result in enhanced antigen presentation, accordingly, this technique may be modified to enhance effects of CAR-DC. The induction of immunity to tumors in the present invention is associated with the unique nature of: a) ongoing basal cell death within the tumor; and b) cell death induced by chemotherapy, radiotherapy, hyperthermia, or otherwise induced cell death. Cell death can be classified according to the morphological appearance of the lethal process (that may be apoptotic, necrotic, autophagic or associated with mitosis), enzymological criteria (with and without the involvement of nucleases or distinct classes of proteases, like caspases), functional aspects (programmed or accidental, physiological or pathological) or immunological characteristics (immunogenic or non-immunogenic). Cell death is defined as “immunogenic” or “immune stimulatory” if dying cells that express a specific antigen (for example a tumor associated antigen, phosphotidyl serine, or calreticulin), yet are uninfected (and hence lack pathogen-associated molecular patterns), and are injected subcutaneously into mice, in the absence of any adjuvant, cause a protective immune response against said specific antigen. Such a protective immune response precludes the growth of living transformed cells expressing the specific antigen injected into mice. When cancer cells succumb to an immunogenic cell death (or immunogenic apoptosis) modality, they stimulate the immune system, which then mounts a therapeutic anti-cancer immune response and contributes to the eradication of residual tumor cells. Conversely, when cancer cells succumb to a non-immunogenic death modality, they fail to elicit such a protective immune response. Regardless of the types of cell death that are ongoing, the tumor derived immune suppressive molecules contribute to general inhibition or inability of the tumor to be eliminated.
• Within the practice of the invention, CAR-DC are administered concurrently, prior to, or subsequent to administration of an agent that induces immunogenic cell death in a patient. Methods of determining whether compounds induce immunogenic cell death are known in the art and include the following, which was described by Zitvogel et al. (a) treating the cells, the mammalian cells and inducing the cell death or apoptosis, typically of mammalian cancer cells capable of expressing calreticulin (CRT), by exposing said mammalian cells to a particular drug (the test drug), for example 18 hours; (b) inoculating (for example intradermally) the dying mammalian cells from step (a) in a particular area (for example a flank) of the mammal, typically a mouse, to induce an immune response in this area of the mammal; (c) inoculating (for example intradermally) the minimal tumorigenic dose of syngeneic live tumor cells in a distinct area (for example the opposite flank) from the same mammal, for example 7 days after step (b); and (d) comparing the size of the tumor in the inoculated mammal with a control mammal also exposed to the minimal tumorigenic dose of syngeneic live tumor cells of step (c) [for example a mouse devoid of T lymphocyte], the stabilization or regression of the tumor in the inoculated mammal being indicative of the drug immunogenicity. Other in vitro means are available for assessing the ability of various drugs or therapeutic approaches to induce immunogenic cell death. Specific characteristics to assess when screening for immunogenic cell death include: a) ability to induce dendritic cell maturation in vitro; b) ability to activate NK cells; and c) ability to induce activation of gamma delta T cells or NKT cells. Specific drugs known to induce immunogenic cell death include oxiplatine and anthracyclines, as well as radiotherapy, and hyperthermia. In the case of chemotherapies, certain chemotherapies that activate TLR4 through induction of HMGB1 have been observed to function suboptimally in patients that have a TLR4 polymorphism, thus suggesting actual contribution of TLR activation as a means of chemotherapy inhibition of cancer. Additionally, oncoviruses or oncolytic viruses are known to induce immunogenic cell death and may be useful for the practice of the invention.
• The CAR-DC disclosed in the invention may be utilized in combination with conventional immune modulators including BCG, CpG DNA, interferon alpha, tumor bacterial therapy, checkpoint inhibitors, Treg depleting agents, and low dose cyclophosphamide.
• In one embodiment of the invention CAR-DC cells are generated with specificity towards ROBO-4. Numerous means of generating CAR-T cells are known in the art, which are applied to CAR-DC. In one embodiment of the invention FMC63-28z CAR (Genebank identifier HM852952.1), is used as the template for the CAR except the anti-CD19, single-chain variable fragment sequence is replaced with an ROBO-4 fragment. The construct is synthesized and inserted into a pLNCX retroviral vector. Retroviruses encoding the ROBO-4-specific CAR are generated using the retrovirus packaging kit, Ampho (Takara), following the manufacturer's protocol. For generation of CAR-DC cells donor blood is obtained and after centrifugation on Ficoll-Hypaque density gradients (Sigma-Aldrich), PBMCs are plated at 2×10(6) cells/mL in cell culture for 2 hours and the adherent cells are collected. The cells were then stimulated for 2 days on a tissue-culture-treated 24-well plate containing M-CSF at a concentration of 100 ng/ml For retrovirus transduction, a 24-well plate are coated with RetroNectin (Takara) at 4° C. overnight, according to the manufacturer's protocol, and then blocked with 2% BSA at room temperature for 30 min. The plate was then loaded with retrovirus supernatants at 300 μL/well and incubated at 37° C. for 6 h. Next, 1×10(6) stimulated adherent cells in 1 mL of medium are added to 1 mL of retrovirus supernatants before being transferred to the pre-coated wells and cultured at 37° C. for 2 d. The cells are then transferred to a tissue-culture-treated plate at 1×10 (6)cells/mL and cultured in the presence of 100 U/mL of recombinant human M-CSF, applying the T cell protocol but not utilizing IL-2 or antiCD3/antiCD28.
• Other means of generating CARs are known in the art and incorporated by reference. For example, Groner's group genetically modified T lymphocytes and endowed them with the ability to specifically recognize cancer cells. Tumor cells overexpressing the ErbB-2 receptor served as a model. The target cell recognition specificity was conferred to T lymphocytes by transduction of a chimeric gene encoding the zeta-chain of the TCR and a single chain antibody (scFv(FRPS)) directed against the human ErbB-2 receptor. The chimeric scFv(FRPS)-zeta gene was introduced into primary mouse T lymphocytes via retroviral gene transfer. Naive T lymphocytes were activated and infected by cocultivation with a retrovirus-producing packaging cell line. The scFv(FRPS)-zeta fusion gene was expressed in >75% of the T cells. These T cells lysed ErbB-2-expressing target cells in vitro with high specificity. In a syngeneic mouse model, mice were treated with autologous, transduced T cells. The adoptively transferred scFv(FRP5)-zeta-expressing T cells caused total regression of ErbB-2-expressing tumors. The presence of the transduced T lymphocytes in the tumor tissue was monitored. No humoral response directed against the transduced T cells was observed. Abs directed against the ErbB-2 receptor were detected upon tumor lysis. Hombach et al. constructed an anti-CEA chimeric receptor whose extracellular moiety is composed of a humanized scFv derived from the anti-CEA mAb BW431/26 and the CH2/CH3 constant domains of human IgG. The intracellular moiety consists of the gamma-signaling chain of the human Fc epsilon RI receptor constituting a completely humanized chimeric receptor. After transfection, the humBW431/26 scFv-CH2CH3-gamma receptor is expressed as a homodimer on the surface of MD45 T cells. Co-incubation with CEA+ tumor cells specifically activates grafted MD45 T cells indicated by IL-2 secretion and cytolytic activity against CEA+ tumor cells. Notably, the efficacy of receptor-mediated activation is not affected by soluble CEA up to 25 micrograms/ml demonstrating the usefulness of this chimeric receptor for specific cellular activation by membrane-bound CEA even in the presence of high concentrations of CEA, as found in patients during progression of the disease (200). These methods are described to guide one of skill in the art to practicing the invention, which in one embodiment is the utilization of CAR T cell approaches towards targeting tumor endothelium as comparted to simply targeting the tumor itself.
• Targeting of mucins associated with cancers has been performed with CAR T cells by grafting the antibody that binds to the mucin with CD3 zeta chain. For the purpose of the invention, this procedure is modified for CAR-DC. In an older publication chimeric immune receptor consisting of an extracellular antigen-binding domain derived from the CC49 humanized single-chain antibody, linked to the CD3zeta signaling domain of the T cell receptor, was generated (CC49-zeta). This receptor binds to TAG-72, a mucin antigen expressed by most human adenocarcinomas. CC49-zeta was expressed in CD4+ and CD8+ T cells and induced cytokine production on stimulation. Human T cells expressing CC49-zeta recognized and killed tumor cell lines and primary tumor cells expressing TAG-72. CC49-zeta T cells did not mediate bystander killing of TAG-72-negative cells. In addition, CC49-zeta T cells not only killed FasL-positive tumor cells in vitro and in vivo, but also survived in their presence, and were immunoprotective in intraperitoneal and subcutaneous murine tumor xenograft models with TAG-72-positive human tumor cells. Finally, receptor-positive T cells were still effective in killing TAG-72-positive targets in the presence of physiological levels of soluble TAG-72, and did not induce killing of TAG-72-negative cells under the same conditions.
• For clinical practice of the invention several reports exist in the art that would guide the skilled artisan as to concentrations, cell numbers, and dosing protocols useful. While in the art CAR T cells have been utilized targeting surface tumor antigens, the main issue with this approach is the difficulty of T cells to enter tumors due to features specific to the tumor microenvironment. These include higher interstitial pressure inside the tumor compared to the surroundings, acidosis inside the tumor, and expression in the tumor of FasL which kills activated T cells. Accordingly the invention seeks to more effectively utilize CAR-DC cells by directly targeting them to tumor endothelium, which is in direct contact with blood and therefore not susceptible to intratumoral factors the limit efficacy of conventional T cell therapies. In other embodiments CAR-DC are targeting to tumor antigens.
• In one embodiment of the invention, protocols similar to Kershaw et al. are utilized with the exception that tumor endothelial antigens are targeted as opposed to conventional tumor antigens. Such tumor endothelial antigens include CD93, TEM-1, VEGFR1, and survivin. Antibodies can be made for these proteins, methodologies for which are described in U.S. Pat. Nos. 5,225,539, 5,585,089, 5,693,761, and 5,639,641. In one example that may be utilized as a template for clinical development, T cells with reactivity against the ovarian cancer-associated antigen alpha-folate receptor (FR) were generated by genetic modification of autologous T cells with a chimeric gene incorporating an anti-FR single-chain antibody linked to the signaling domain of the Fc receptor gamma chain. Patients were assigned to one of two cohorts in the study. Eight patients in cohort 1 received a dose escalation of T cells in combination with high-dose interleukin-2, and six patients in cohort 2 received dual-specific T cells (reactive with both FR and allogeneic cells) followed by immunization with allogeneic peripheral blood mononuclear cells. Five patients in cohort 1 experienced some grade 3 to 4 treatment-related toxicity that was probably due to interleukin-2 administration, which could be managed using standard measures. Patients in cohort 2 experienced relatively mild side effects with grade 1 to 2 symptoms. No reduction in tumor burden was seen in any patient. Tracking 111In-labeled adoptively transferred T cells in cohort 1 revealed a lack of specific localization of T cells to tumor except in one patient where some signal was detected in a peritoneal deposit. PCR analysis showed that gene-modified T cells were present in the circulation in large numbers for the first 2 days after transfer, but these quickly declined to be barely detectable 1 month later in most patients. Similar CAR-T clinical studies have been reported for neuroblastoma, B cell malignancies, melanoma, ovarian cancer, renal cancer, mesothelioma, and head and neck cancer.
• In one embodiment of the invention, PBMCs are derived from leukapheresis and CD14 monocytes are collected by MACS. After 3 days of culture, M-CSF at 100 ng/ml plasmid encoding the chimeric CAR-DC recognizing tumor-endothelium specific antigen and subsequently selected for gene integration by culture in G418. In another embodiment the generation of dual-specific T cells is performed, stimulation of allogeneic monocytic cells is achieved by coculture of patient PBMCs with irradiated (5,000 cGy) allogeneic donor PBMCs from cryopre-served apheresis product (mixed lymphocyte reaction). The MHC haplotype of allogeneic donors is determined before use, and donors that differed in at least four MHC class I alleles from the patient are used. Culture medium consisted of AimV medium (Invitrogen, Carlsbad, Calif.) supplemented with 5% human AB⁻ serum (Valley Biomedical, Winchester, Va.), penicillin (50 units/mL), streptomycin (50 mg/mL; Bio Whittaker, Walkersville, Md.), amphotericin B (Fungizone, 1.25 mg/mL; Biofluids, Rockville, Md.), L-glutamine (2 mmol/L; Mediatech, Herndon, Va.), and human recombinant IL-2 (Proleukin, 300 IU/mL; Chiron). Mixed lymphocyte reaction consisted of 2×10⁶patient monocytes and 1×10⁷allogeneic stimulator PBMCs in 2 mL AimV per well in 24-well plates. Between 24 and 48 wells are cultured per patient for 3 days, at which time transduction is done by aspirating 1.5 mL of medium and replacing with 2.0 mL retroviral supernatant containing 300 IU/mL IL-2, 10 mmol/L HEPES, and 8 μg/mL polybrene (Sigma, St. Louis, Mo.) followed by covering with plastic wrap and centrifugation at 1,000×g for 1 hour at room temperature. After overnight culture at 37° C./5% CO₂, transduction is repeated on the following day, and then medium was replaced after another 24 hours. Cells are then resuspended at 1×10⁶/mL in fresh medium containing 0.5 mg/mL G418 (Invitrogen) in 175-cm²flasks for 5 days before resuspension in media lacking G418. Cells are expanded to 2×10⁹and then restimulated with allogeneic PBMCs from the same donor to enrich for T cells specific for the donor allogeneic haplotype. Restimulation is done by incubating patient T cells (1×10⁶/mL) and stimulator PBMCs (2×10⁶/mL) in 3-liter Fenwall culture bags in AimV+additives and IL-2 (no G418). Cell numbers were adjusted to 1×10⁶/mL, and IL-2 was added every 2 days, until sufficient numbers for treatment were achieved.
• The present invention relates to a strategy of adoptive cell transfer of monocytes or DC transduced to express a chimeric antigen receptor (CAR). CARs are molecules that combine antibody-based specificity for a desired antigen (e.g., tumor endothelial antigen) with a T cell receptor-activating intracellular domain to generate a chimeric protein that exhibits a specific anti-tumor endothelium cellular immune activity. In one embodiment the present invention relates generally to the use of monocytes or DC cells genetically modified to stably express a desired CAR that possesses high affinity towards tumor associated endothelium. Monocytes or DC cells expressing a CAR are referred to herein as CAR-DC cells or CAR modified DC cells. Preferably, the cell can be genetically modified to stably express an antibody binding domain on its surface, conferring novel antigen specificity that is MHC independent. In some instances, the monocyte or DC cell is genetically modified to stably express a CAR that combines an antigen recognition domain of a specific antibody with an intracellular domain of the CD3-zeta chain or Fc.gamma.RI protein into a single chimeric protein. In another embodiment, TLR signaling molecules are engineered in the intracellular portion of the CAR, said molecules include TRIF, TRADD, and MyD99. In one embodiment, the CAR of the invention comprises an extracellular domain having an antigen recognition domain, a transmembrane domain, and a cytoplasmic domain. In one embodiment, the transmembrane domain that naturally is associated with one of the domains in the CAR is used. In another embodiment, the transmembrane domain can be selected or modified by amino acid substitution to avoid binding of such domains to the transmembrane domains of the same or different surface membrane proteins to minimize interactions with other members of the receptor complex. Preferably, the transmembrane domain is the CD8a hinge domain.
• With respect to the cytoplasmic domain, the CAR of the invention can be designed to comprise the CD80 and/or CD86 and/or CD40L and/or OX40L signaling domain by itself or be combined with any other desired cytoplasmic domain(s) useful in the context of the CAR of the invention. In one embodiment, the cytoplasmic domain of the CAR can be designed to further comprise the signaling domain of MyD88. For example, the cytoplasmic domain of the CAR can include but is not limited to CD80 and/or CD86 and/or CD40L and/or OX40L signaling modules and combinations thereof. In another embodiment of the invention inhibition of TGF-beta is performed either by transfection with an shRNA possessing selectively towards TGF-beta or by constructing the CAR to possess a dominant negative mutant of TGF-beta receptor. This would render the CAR-DC cell resistant to inhibitory activities of the tumors. Accordingly, the invention provides CAR-DC cells and methods of their use for adoptive therapy. In one embodiment, the CAR-DC cells of the invention can be generated by introducing a lentiviral vector comprising a desired CAR, for example a CAR comprising anti-CD19, CD8a hinge and transmembrane domain, and MyD88, into the cells. The CAR-DC cells of the invention are able to replicate in vivo resulting in long-term persistence that can lead to sustained tumor control.
• One skilled in the art will appreciate that these methods, compositions, and cells are and may be adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. The methods, procedures, and devices described herein are presently representative of preferred embodiments and are exemplary and are not intended as limitations on the scope of the invention. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the disclosure. It will be apparent to one skilled in the art that varying substitutions and modifications may be made to the invention disclosed herein without departing from the scope and spirit of the invention. Those skilled in the art recognize that the aspects and embodiments of the invention set forth herein may be practiced separate from each other or in conjunction with each other. Therefore, combinations of separate embodiments are within the scope of the invention as disclosed herein. All patents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
• The invention illustratively described herein suitably may be practiced in the absence of any element or elements, limitation or limitations which is not specifically disclosed herein. Thus, for example, in each instance herein any of the terms “comprising,” “consisting essentially of” and “consisting of” may be replaced with either of the other two terms. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions indicates the exclusion of equivalents of the features shown and described or portions thereof. It is recognized that various modifications are possible within the scope of the invention disclosed. 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 concepts 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 as defined by the disclosure.

Claims (26)

1. A method of treating cancer comprising of: a) extracting a blood sample from a cancer patient; b) isolating monocytes from said blood sample; c) transfecting said monocytes from said blood sample with a construct encoding a chimeric antigen receptor; and d) infusing said transfected monocytes into said cancer patient.

2. The method ofclaim 1, wherein peripheral blood mononuclear cells (PBMC) are purified from said blood sample.

3. The method ofclaim 2, wherein said purification of said PBMC is performed using a density gradient.

4. The method ofclaim 3, wherein said density gradient is ficoll.

5. The method ofclaim 1, wherein said monocytes are isolated from said blood sample by isolation of cells expressing CD14.

6. The method ofclaim 1, wherein said monocytes are isolated from said blood sample by collection of cells adhering to a plastic vessel after a culture period of at least one hour.

7. The method ofclaim 5, wherein said CD14 expressing cells are isolated by magnetic activated cell sorting (MACS).

8. The method ofclaim 5, wherein said CD14 expressing cells are isolated by fluorescent activated cell sorting (FACS).

9. The method ofclaim 1, wherein said chimeric antigen receptor construct encodes a protein comprising of: a) an antigen binding domain; b) a transmembrane domain; and c) an intracellular domain.

10. The method ofclaim 9, wherein said antigen binding domain is an antibody or fragment thereof.

11. The method ofclaim 9, wherein said antigen binding domain is single chain antibody or fragment thereof.

12. The method ofclaim 9, wherein said antibody domain is a molecular entity possessing affinity towards a tumor antigen or a tumor endothelial antigen.

13. The method ofclaim 1, wherein said antibody binding domain possesses affinity towards a tumor endothelial cell antigen.

14. The method ofclaim 13, wherein said tumor endothelial cell antigen is selected from a group of antigens comprising of:

a) TEM-1;

b) ROBO-1-8;

c) VEGFR2;

d) CD109;

e) survivin; and

f) CD93.

15. The method ofclaim 1, wherein said antibody binding domain possesses affinity towards a tumor antigen.

16. The method ofclaim 15, wherein said tumor antigens are selected from a group comprising of: CLPP, 707-AP, AFP, ART-4, BAGE, MAGE, GAGE, SAGE, b-catenin/m, bcr-abl, CAMEL, CAP-1, CEA, CASP-8, CDK/4, CDC-27, Cyp-B, DAM-8, DAM-10, ELV-M2, ETV6, G250, Gp100, HAGE, HER-2/neu, EPV-E6, LAGE, hTERT, survivin, iCE, MART-1, tyrosinase, MUC-1, MC1-R, TEL/AML, and WT-1.

17. The method ofclaim 1, wherein said intracellular domain of said CAR is capable of inducing monocytic differentiation to DC.

18. The method ofclaim 1, wherein said intracellular domain of said CAR is capable of inducing monocytic differentiation to M1 macrophages.

19. The method ofclaim 1, wherein said intracellular domain of said CAR is capable of activating a toll like receptor signaling pathway.

20. The method ofclaim 1, wherein said intracellular domain of said CAR is capable of activating TLR4 signaling.

21. The method ofclaim 1, wherein said intracellular domain of said CAR is capable of inducing monocytic differentiation to DC.

22. The method ofclaim 1, wherein said intracellular domain of said CAR contains a signaling portion of the intracellular domain of the TLR-4 protein.

23. The method ofclaim 1, wherein said intracellular domain of said CAR contains an activator of molecular pathways endowing M1 phenotype is the functional portion of said TLR-4 protein which interacts with MyD88 at a sufficient affinity to trigger said MyD88 signal transduction.

24. The method ofclaim 1, wherein said intracellular domain of said CAR contains an activator of molecular pathways endowing DC phenotype is the functional portion of said TLR-4 protein which interacts with MyD88 at a sufficient affinity to trigger said MyD88 signal transduction.

25. The method ofclaim 1, wherein said activator of molecular pathways endowing M1 phenotype is the functional portion of said TLR-4 protein which interacts with TRAM and MAL at a sufficient affinity to trigger said TLR4 signal transduction.

26. The method ofclaim 1, wherein said activator of molecular pathways endowing DC phenotype is the functional portion of said TLR-4 protein which interacts with TRAM and MAL at a sufficient affinity to trigger said TLR4 signal transduction.