anti-CD4 (human), Rabbit Monoclonal (RM345)

Human CD4 is a cell surface glycoprotein of 55kDa expressed on most thymocytes, on about two thirds of peripheral T helper cells and on some monocyte macrophage lineage cells and dendritic cells. CD4 interacts with MHC Class II molecules in an accessory role during foreign antigen recognition by T cells. The extracellular portion of CD4 is an array of four Ig-like domains. The N-terminal region of CD4 is a receptor for the HIV-1 viral protein gp120. At the tissue level, CD4 expression may be detected in thymus, lymph nodes, tonsils, and spleen and also in specific regions of the brain, gut and other non-lymphoid tissues. CD4 functions to initiate or augment the early phase of T cell activation through its association with the T cell receptor complex and protein tyrosine kinase, Lck. It may also function as an important mediator of direct neuronal damage in infectious and immune-mediated diseases of the central nervous system.