CD8a Antibody [53-6.7]

In the mouse, CD8 exists in two forms – (i) a CD8 heterodimer composed of an alpha chain (CD8alpha) and a beta chain (CD8beta) ; and (ii) a homodimer of two alpha chains. The heterodimer is found on the surface of essentially all thymocytes and the “suppressor/cytotoxic” subpopulation of mature T lymphocytes. Subsets of intestinal intraepithelial lymphocytes express CD8alpha without CD8beta. It has been suggested that CD8+beta- T cells mature extrathymically, while development of the CD8alpha+beta+ population of T cells is thymus-dependent. CD8 acts as a coreceptor with MHC Class I-restricted T cell receptors in antigen recognition and positive selection of MHC class I-restricted CD8+ T cells. In vivo and in vitro treatment with the 53-6.7 monoclonal antibody effectively depletes CD8alpha+ cells. The 53-6.7 monoclonal antibody also blocks allogeneic help specific for class I MHC antigens and T cell responses to IL-2.