CD5[5] is acluster of differentiation expressed on the surface ofT cells (various species) and in a subset of murine B cells known asB-1a. The expression of this receptor in human B cells has been a controversial topic and to date there is no consensus regarding the role of this receptor as a marker of human B cells. B-1 cells have limited diversity of theirB-cell receptor due to their lack of the enzymeterminal deoxynucleotidyl transferase (TdT) and are potentially self-reactive. CD5 serves to mitigate activating signals from the BCR so that the B-1 cells can only be activated by very strong stimuli (such as bacterial antigen) and not by normal tissue antigen. CD5 was used as a T-cell marker untilmonoclonal antibodies againstCD3 were developed.
In humans, the gene is located on the long arm ofchromosome 11. There is no confirmed ligand for CD5 but there is evidence that CD72, a C-type lectin, may be a ligand or that CD5 may be homophilic, binding CD5 on the surface of other cells.[6] CD5 includes ascavenger receptor cysteine-rich protein domain.
T cells express higher levels of CD5 than B cells. CD5 is upregulated on T cells upon strong activation. In thethymus, there is a correlation with CD5 expression and strength of the interaction of the T cell towards self-peptides.
Osman N, Ley SC, Crumpton MJ (November 1992). "Evidence for an association between the T cell receptor/CD3 antigen complex and the CD5 antigen in human T lymphocytes".European Journal of Immunology.22 (11):2995–3000.doi:10.1002/eji.1830221135.PMID1385158.S2CID34625072.
Jones NH, Clabby ML, Dialynas DP, Huang HJ, Herzenberg LA, Strominger JL (1986). "Isolation of complementary DNA clones encoding the human lymphocyte glycoprotein T1/Leu-1".Nature.323 (6086):346–349.Bibcode:1986Natur.323..346J.doi:10.1038/323346a0.PMID3093892.S2CID4361866.
Lankester AC, van Schijndel GM, Cordell JL, van Noesel CJ, van Lier RA (April 1994). "CD5 is associated with the human B cell antigen receptor complex".European Journal of Immunology.24 (4):812–816.doi:10.1002/eji.1830240406.PMID7512031.S2CID25093082.
Dianzani U, Bragardo M, Buonfiglio D, Redoglia V, Funaro A, Portoles P, et al. (May 1995). "Modulation of CD4 lateral interaction with lymphocyte surface molecules induced by HIV-1 gp120".European Journal of Immunology.25 (5):1306–1311.doi:10.1002/eji.1830250526.PMID7539755.S2CID37717142.
Van de Velde H, Thielemans K (August 1996). "Native soluble CD5 delivers a costimulatory signal to resting human B lymphocytes".Cellular Immunology.172 (1):84–91.doi:10.1006/cimm.1996.0218.PMID8806810.
Dennehy KM, Broszeit R, Garnett D, Durrheim GA, Spruyt LL, Beyers AD (March 1997). "Thymocyte activation induces the association of phosphatidylinositol 3-kinase and pp120 with CD5".European Journal of Immunology.27 (3):679–686.doi:10.1002/eji.1830270316.PMID9079809.S2CID41540340.
Gary-Gouy H, Lang V, Sarun S, Boumsell L, Bismuth G (October 1997). "In vivo association of CD5 with tyrosine-phosphorylated ZAP-70 and p21 phospho-zeta molecules in human CD3+ thymocytes".Journal of Immunology.159 (8):3739–3747.doi:10.4049/jimmunol.159.8.3739.PMID9378960.S2CID42470132.
Mier-Aguilar CA, Vega-Baray B, Burgueño-Bucio E, Lozano F, García-Zepeda EA, Raman C, et al. (October 2015). "Functional requirement of tyrosine residue 429 within CD5 cytoplasmic domain for regulation of T cell activation and survival".Biochemical and Biophysical Research Communications.466 (3):381–387.Bibcode:2015BBRC..466..381M.doi:10.1016/j.bbrc.2015.09.033.PMID26363459.
.jpg)
