HLA, the human form of the major histocompatibility complex (MHC), is located on chromosome 6 at 6p21.3. Individuals inherit two different HLA haplotypes, one from each parent, each containing more than 200 genes relevant to helping the immune system recognize foreign invaders. These genes include MHC class I and class II cell-surface proteins. MHC Class I molecules—HLA-A, HLA-B, and HLA-C—are present on all nucleated cells and are responsible for signaling to an immune cell that an antigen is inside the cell. MHC Class II molecules—HLA-DR, and HLA-DQ and HLA-DP—are only present on antigen presenting cells and are responsible for presenting molecules from invading organisms to cells of the immune system.
HLA the human form of the major histocompatibility complex (MHC), is located on chromosome 6 at 6p21.3. Individuals inherit two different HLA haplotypes, one from each parent, each containing more than 200 genes relevant to helping the immune system recognize foreign invaders. These genes include M,HC class I and class II cell-surface proteins. MHC Class I molecules—HLA-A, HLA-B, and HLA-C—are present on all nucleated cells and are responsible for signaling to an immune cell that an antigen is inside the cell. MHC Class II molecules—HLA-DR, and HLA-DQ and HLA-DP—are only present on antigen presenting cells and are responsible for presenting molecules from invading organisms to cells of the immune system.