Abstract
MHC ANTIGENS
The Major Histocompatibility Complex contains several classes of structurally related loci. Their products, originally defined as the major transplantation antigens, are now known to play an important role in cell-mediated immunity. The MHC Class I and II antigens function as “receptor” molecules for foreign peptide(s). These complexes of peptide and MHC molecule are presented—often by specialized antigen presenting cells of the immune system—to specific receptors on the T cell. This primary recognition event leads to the generation of both cytotoxic (CTL) and helper (Th) cells in the T cell lineage and antibody secreting cells in the B cell lineage.