Histocompatibility Antigens Class II

**Definition:** Large, transmembrane, non-covalently linked glycoproteins (alpha and beta). Both chains can be polymorphic although there is more structural variation in the beta chains. The class II antigens in humans are called HLA-D ANTIGENS and are coded by a gene on chromosome 6. In mice, two genes named IA and IE on chromosome 17 code for the H-2 antigens. The antigens are found on B-lymphocytes, macrophages, epidermal cells, and sperm and are thought to mediate the competence of and cellular cooperation in the immune response. The term IA antigens used to refer only to the proteins encoded by the IA genes in the mouse, but is now used as a generic term for any class II histocompatibility antigen.

**Tree numbers:** - D09.400.430.890.509 - D12.776.395.550.509 - D12.776.543.550.440 - D23.050.301.500.400 - D23.050.705.552.410

**Synonyms:** - Class II Major Histocompatibility Molecules - MHC-II Molecules - MHC II Peptides - Class II MHC Proteins - Ia-Like Antigens - IA Antigen - Class II Histocompatibility Antigen - Ia Antigens - Class II Major Histocompatibility Antigen - Ia-Like Antigen - Antigens, Immune Response - Immune Response Antigens - Immune-Response-Associated Antigens - Class II Major Histocompatibility Antigens - I-A-Antigen - I-A Antigen - MHC Class II Molecule - MHC II Peptide - Class II Antigen - Class II Antigens - MHC Class II Molecules - Class II Histocompatibility Antigens