Description
CD4 is a 55 kD protein also known as L3T4 or T4. It is a member of the Ig superfamily, primarily expressed on most thymocytes, a subset of T cells, and weakly on macrophages and dendritic cells. It acts as a coreceptor with the TCR during T cell activation and thymic differentiation by binding MHC class II and associating with the protein tyrosin kinase, lck.
Application Notes
Additional reported applications (for the relevant formats) include: blocking of CD4+ T cell activation1,4,11, thymocyte costimulation3, in vitro and in vivo depletion2,5-8, blocking of egg-sperm cell adhesion1,4, immunohistochemical staining of acetone-fixed frozen sections9,10, immunoprecipitation1,2, and spatial biology (IBEX)12,13. The GK1.5 antibody is able to block CD4 mediated cell adhesion and T cell activation. Binding of GK1.5 antibody to CD4 T cells can be blocked by RM4-5 antibody, but not RM4-4 antibody. For in vivo studies or highly sensitive assays, we recommend Ultra-LEAF™ purified antibody (Cat. No. 100442) with a lower endotoxin limit than standard LEAF™ purified antibodies (Endotoxin < 0.01 EU/µg).