Cluster of differentiation 4 / CD4

What is CD4/cluster of differentiation 4 ?

Cluster of differentiation antigen 4 /CD4, the T lymphocyte antigen receptor component and human immunodeficiency virus coreceptor, is down-modulated when cells are activated by antigen or phorbolesters. Cluster of differentiation 4 is a glycoprotein found on the surface of cells such as T cells, monocytes, macrophages, and dendritic cells.

What is the role of Cluster of differentiation antigen 4 /CD4 in the immune system?

CD4 is a co-receptor that assists the T cell receptor (TCR). Using its intracellular domain, CD4 amplifies the signal generated by the TCR by recruiting an enzyme, the signaling cascade of an activated T cell. Various types of T helper cells are thereby produced. CD4 also interacts directly with MHC class II molecules on the surface of the antigen-presenting cell using its extracellular domain. During antigen presentation, both the TCR complex and CD4 are recruited to bind to different regions of the MHCII molecule.

What is the role of Cluster of differentiation antigen 4 /CD4 in HIV ?

HIV infection leads to a progressive reduction in the number of T cells expressing CD4. Medical professionals refer to the CD4 count to decide when to begin treatment during HIV infection. Normal blood values are usually expressed as the number of cells per microliter of blood, with normal values for CD4 cells being 500-1200 cells/mm3. A CD4 count measures the number of T cells expressing CD4.

Cluster of differentiation antigen 4 /CD4 in other diseases

CD4 continues to be expressed in most neoplasms derived from T helper cells. It is therefore possible to use CD4 immunohistochemistry on tissue biopsy samples to identify most forms of peripheral T cell lymphoma and related malignant conditions. The antigen has also been associated with a number of autoimmune diseases such as vitiligo and type I diabetes mellitus.

Cluster of differentiation antigen 4 /CD4 Reasearch Reagent Category

Cluster of differentiation 4 / CD4: Reference

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4. Rudd CE, Trevillyan JM, Dasgupta JD, et al. The CD4 receptor is complexed in detergent lysates to a protein-tyrosine kinase (pp58) from human T lymphocytes. Proc. Natl. Acad. Sci, 1988
5. Kwong PD, Wyatt R, Robinson J, Sweet RW, Sodroski J, Hendrickson WA. Structure of an HIV gp120 envelope glycoprotein in complex with the CD4 receptor and a neutralizing human antibody. Nature , 1998
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7. Kumarasen Cooper, Anthony S-Y. Leong. Manual of diagnostic antibodies for immunohistology. London: Greenwich Medical Media, 2003
8. Zamani M, Tabatabaiefar MA, Mosayyebi S, et al. Possible association of the CD4 gene polymorphism with vitiligo in an Iranian population. Clin. Exp. Dermatol, 2010