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HLA antigens
the human major histocompatibility complex, located on the short arm of chromosome 6. Five loci have been identified, designated HLA-A, HLA-B, HLA-C, HLA-D, and HLA-DR
(D related), each with multiple alleles, designated by numerals (such as HLA-B5). Provisionally identified alleles are designated by the letter w (such as HLA-Bw22). Called also human leukocyte antigens. The HLA-A, -B, and -C loci gene products are cell surface antigens found on the surface of all nucleated cells. They are
the most important antigens in transplant rejection, when donor and recipient HLA antigens do not match. The HLA-A, -B, and -C antigens are recognized by killer T cells that lyse the target cells and are also involved in the cell-mediated lysis of virus-infected cells. The HLA-D and -DR loci
gene products are cell surface antigens of B lymphocytes and macrophages and are involved in antigen presentation and other forms of cooperation between immunocompetent cells as well as in stimulation of transplant rejection.
Copyright 2007. An Elsevier publication. All rights reserved.
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