| CD4, Cluster of differentiation 4, extracellular | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 structure of T cell surface glycoprotein cd4, monoclinic crystal form | |||||||||
| Identifiers | |||||||||
| Symbol | CD4-extrcel | ||||||||
| Pfam | PF09191 | ||||||||
| InterPro | IPR015274 | ||||||||
| SCOP2 | 1cid / SCOPe / SUPFAM | ||||||||
| OPM superfamily | 193 | ||||||||
| OPM protein | 2klu | ||||||||
| CDD | cd07695 | ||||||||
| Membranome | 27 | ||||||||
| |||||||||
In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as helper T cells, monocytes, macrophages, and dendritic cells. It was discovered in the late 1970s and was originally known as leu-3 and T4 (after the OKT4 monoclonal antibody that reacted with it) before being named CD4 in 1984.[5] In humans, the CD4 protein is encoded by the CD4 gene.[6][7]
CD4+ T helper cells are white blood cells that are an essential part of the human immune system. They are often referred to as CD4 cells, T helper cells or T4 cells. They are called helper cells because one of their main roles is to send signals to other types of immune cells, including CD8 killer cells, which then destroy the infectious particle. If CD4 cells become depleted, for example in untreated HIV infection, or following immune suppression prior to a transplant, the body is left vulnerable to a wide range of infections that it would otherwise have been able to fight.
- ^ a b c GRCh38: Ensembl release 89: ENSG00000010610 – Ensembl, May 2017
- ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000023274 – Ensembl, May 2017
- ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- ^ Bernard A, Boumsell L, Hill C (1984). "Joint Report of the First International Workshop on Human Leucocyte Differentiation Antigens by the Investigators of the Participating Laboratories". In Bernard A, Boumsell L, Dausset J, Milstein C, Schlossman SF (eds.). Leucocyte typing: human leucocyte differentiation antigens detected by monoclonal antibodies: specification, classification, nomenclature. Berlin: Springer. pp. 45–48. doi:10.1007/978-3-642-68857-7_3. ISBN 0-387-12056-4.
Report on the first international references workshop sponsored by INSERM, WHO and IUIS
- ^ Isobe M, Huebner K, Maddon PJ, Littman DR, Axel R, Croce CM (June 1986). "The gene encoding the T-cell surface protein T4 is located on human chromosome 12". Proceedings of the National Academy of Sciences of the United States of America. 83 (12): 4399–4402. Bibcode:1986PNAS...83.4399I. doi:10.1073/pnas.83.12.4399. PMC 323740. PMID 3086883.
- ^ Ansari-Lari MA, Muzny DM, Lu J, Lu F, Lilley CE, Spanos S, et al. (April 1996). "A gene-rich cluster between the CD4 and triosephosphate isomerase genes at human chromosome 12p13". Genome Research. 6 (4): 314–326. doi:10.1101/gr.6.4.314. PMID 8723724.