About InVivoMAb anti-human CD4

The RPA-T4 monoclonal antibody reacts with the human CD4. The CD4 antigen is a 55 kDa cell surface type I membrane glycoprotein belonging to the immunoglobulin superfamily. CD4 acts as a co-receptor which in cooperation with the T cell receptor (TCR) interacts with class II MHC molecules displayed by antigen presenting cells (APC). CD4 is expressed by most thymocytes and helper T cells, a subset of NK-T cells and weakly by dendritic cells and macrophages. CD4 plays an important role in the development of T cells and is required for mature T cells to function optimally. The RPA-T4 antibody is reported to bind to the D1 domain of CD4 and does not block the binding of the OKT-4 antibody. Additionally, RPA-T4 has been shown to block the binding of HIV gp120 protein to CD4 and inhibit CD4 T cell activation in vitro.