Major histocompatibility complex
Major histocompatibility complexes (MHC) are described as glycoproteins that present a cleaved version of an antigen from an invading organism (epitope). This enables a specific type of T cell to bind to the antigen and go on to kill all cells displaying this antigen. These cell surface complexes have two classes, I and II. MHC class I contains alpha 1, 2 and 3 domains and a Beta-2 microglobulin, MHC class II molecule contains alpha 1 and 2 and beta 1 and 2 (no microglobulin present).