CD5 (protein)

CD5 molecule
PDB rendering based on 2ja4.
Available structures PDB 2JA4, 2JOP, 2JP0, 2OTT
Identifiers
Symbols	CD5; LEU1; T1
External IDs	OMIM: 153340 MGI: 88340 HomoloGene: 7260 GeneCards: CD5 Gene
Gene Ontology Molecular function • glycoprotein binding • receptor activity • transmembrane signaling receptor activity • scavenger receptor activity • protein binding Cellular component • plasma membrane • integral to plasma membrane • external side of plasma membrane • fully spanning plasma membrane Biological process • cell recognition • cell proliferation • induction of apoptosis by extracellular signals • T cell costimulation Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	921	12507
Ensembl	ENSG00000110448	ENSMUSG00000024669
UniProt	P06127	P13379
RefSeq (mRNA)	NM_014207.3	NM_007650.3
RefSeq (protein)	NP_055022.2	NP_031676.3
Location (UCSC)	Chr 11: 60.87 – 60.9 Mb	Chr 19: 10.79 – 10.81 Mb
PubMed search	[1]	[2]

CD5 is a cluster of differentiation found on a subset of IgM-secreting B cells called B-1 cells, and also on T cells. B-1 cells have limited diversity of their B-cell receptor due to their lack of the enzyme terminal 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 proteins) and not by normal tissue proteins. CD5 was used as a T-cell marker until monoclonal antibodies against CD3 were developed.

In humans, the gene is located on the long arm of chromosome 11. There is no ligand confirmed, even if CD72, a C-type lectin, may be considered a probable ligand.

T cells express higher levels of CD5 than B cells. CD5 is upregulated on T cells upon strong activation. In the thymus, there is a correlation with CD5 expression and strength of the interaction of the T cell towards self-peptides.

Immunohistochemistry

CD5 is a good immunohistochemical marker for T-cells, although not as sensitive as CD3. About 76% of T-cell neoplasms are reported to express CD5, and it is also found in small lymphocytic lymphoma, hairy cell leukaemia, and mantle cell lymphoma cells. It is commonly lost in cutaneous T-cell lymphoma, and its absence can be used as an indicator of malignancy in this condition. The absence of CD5 in T cell acute lymphoblastic leukaemia, while relatively rare, is associated with a poor prognosis. CACA DE VACA :)

Further reading

• Berland R, Wortis HH (2002). "Origins and functions of B-1 cells with notes on the role of CD5.". Annu. Rev. Immunol. 20: 253–300. doi:10.1146/annurev.immunol.20.100301.064833. PMID 11861604. 
• Osman N, Ley SC, Crumpton MJ (1992). "Evidence for an association between the T cell receptor/CD3 antigen complex and the CD5 antigen in human T lymphocytes.". Eur. J. Immunol. 22 (11): 2995–3000. doi:10.1002/eji.1830221135. PMID 1385158. 
• Van de Velde H, von Hoegen I, Luo W, et al. (1991). "The B-cell surface protein CD72/Lyb-2 is the ligand for CD5.". Nature 351 (6328): 662–5. doi:10.1038/351662a0. PMID 1711157. 
• Jones NH, Clabby ML, Dialynas DP, et al. (1986). "Isolation of complementary DNA clones encoding the human lymphocyte glycoprotein T1/Leu-1.". Nature 323 (6086): 346–9. doi:10.1038/323346a0. PMID 3093892. 
• Lankester AC, van Schijndel GM, Cordell JL, et al. (1994). "CD5 is associated with the human B cell antigen receptor complex.". Eur. J. Immunol. 24 (4): 812–6. doi:10.1002/eji.1830240406. PMID 7512031. 
• Raab M, Yamamoto M, Rudd CE (1994). "The T-cell antigen CD5 acts as a receptor and substrate for the protein-tyrosine kinase p56lck.". Mol. Cell. Biol. 14 (5): 2862–70. PMC 358654. PMID 7513045. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=358654. 
• Dianzani U, Bragardo M, Buonfiglio D, et al. (1995). "Modulation of CD4 lateral interaction with lymphocyte surface molecules induced by HIV-1 gp120.". Eur. J. Immunol. 25 (5): 1306–11. doi:10.1002/eji.1830250526. PMID 7539755. 
• Van de Velde H, Thielemans K (1996). "Native soluble CD5 delivers a costimulatory signal to resting human B lymphocytes.". Cell. Immunol. 172 (1): 84–91. doi:10.1006/cimm.1996.0218. PMID 8806810. 
• Dennehy KM, Broszeit R, Garnett D, et al. (1997). "Thymocyte activation induces the association of phosphatidylinositol 3-kinase and pp120 with CD5.". Eur. J. Immunol. 27 (3): 679–86. doi:10.1002/eji.1830270316. PMID 9079809. 
• Gary-Gouy H, Lang V, Sarun S, et al. (1997). "In vivo association of CD5 with tyrosine-phosphorylated ZAP-70 and p21 phospho-zeta molecules in human CD3+ thymocytes.". J. Immunol. 159 (8): 3739–47. PMID 9378960. 
• Dennehy KM, Broszeit R, Ferris WF, Beyers AD (1998). "Thymocyte activation induces the association of the proto-oncoprotein c-cbl and ras GTPase-activating protein with CD5.". Eur. J. Immunol. 28 (5): 1617–25. doi:10.1002/(SICI)1521-4141(199805)28:05<1617::AID-IMMU1617>3.0.CO;2-7. PMID 9603468. 
• Bauch A, Campbell KS, Reth M (1998). "Interaction of the CD5 cytoplasmic domain with the Ca2+/calmodulin-dependent kinase IIdelta.". Eur. J. Immunol. 28 (7): 2167–77. doi:10.1002/(SICI)1521-4141(199807)28:07<2167::AID-IMMU2167>3.0.CO;2-L. PMID 9692886. 
• Calvo J, Vildà JM, Places L, et al. (1998). "Human CD5 signaling and constitutive phosphorylation of C-terminal serine residues by casein kinase II.". J. Immunol. 161 (11): 6022–9. PMID 9834084. 
• McAlister MS, Davis B, Pfuhl M, Driscoll PC (1999). "NMR analysis of the N-terminal SRCR domain of human CD5: engineering of a glycoprotein for superior characteristics in NMR experiments.". Protein Eng. 11 (10): 847–53. doi:10.1093/protein/11.10.847. PMID 9862202. 
• Perez-Villar JJ, Whitney GS, Bowen MA, et al. (1999). "CD5 negatively regulates the T-cell antigen receptor signal transduction pathway: involvement of SH2-containing phosphotyrosine phosphatase SHP-1.". Mol. Cell. Biol. 19 (4): 2903–12. PMC 84084. PMID 10082557. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=84084. 
• Carmo AM, Castro MA, Arosa FA (1999). "CD2 and CD3 associate independently with CD5 and differentially regulate signaling through CD5 in Jurkat T cells.". J. Immunol. 163 (8): 4238–45. PMID 10510361. 
• Vilà JM, Calvo J, Places L, et al. (2001). "Role of two conserved cytoplasmic threonine residues (T410 and T412) in CD5 signaling.". J. Immunol. 166 (1): 396–402. PMID 11123317. 
• Vilà JM, Gimferrer I, Padilla O, et al. (2001). "Residues Y429 and Y463 of the human CD5 are targeted by protein tyrosine kinases.". Eur. J. Immunol. 31 (4): 1191–8. doi:10.1002/1521-4141(200104)31:4<1191::AID-IMMU1191>3.0.CO;2-H. PMID 11298344. 
• Kirchgessner H, Dietrich J, Scherer J, et al. (2001). "The transmembrane adaptor protein TRIM regulates T cell receptor (TCR) expression and TCR-mediated signaling via an association with the TCR zeta chain.". J. Exp. Med. 193 (11): 1269–84. doi:10.1084/jem.193.11.1269. PMC 2193385. PMID 11390434. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2193385. 
• Gary-Gouy H, Harriague J, Dalloul A, et al. (2002). "CD5-negative regulation of B cell receptor signaling pathways originates from tyrosine residue Y429 outside an immunoreceptor tyrosine-based inhibitory motif.". J. Immunol. 168 (1): 232–9. PMID 11751967. 

External links

• MeSH CD5+Antigen