The HLA, or major histocompatibility region of man is the major genetic region determining rejection of foreign tissue grafts. In the 20 years that have elapsed since the tentative definition of the first HLA gene product, much progress has been made both in mapping the genes and in biochemically defining the gene products. The A, B and C antigens are thought to be present on all human tissues except erythrocytes, sperm and the layer of tropoblast forming the barrier between foetus and mother. No function has yet been clearly demonstrated for these antigens. The HLA-D locus controls the proliferative response between genetically different lymphocytes. Its products, Ia or DR10 antigens, are complexes of two glycosylated polypeptide chains both of which penetrate through the membranes. These antigens are found on B lymphocytes and monocytes. In humans they are closely associated with many diseases and may play a role in the control of immune responses. The complement components C2 and factor B are also thought to be structurally similar and thus, presumably gene duplicates. The major function of serum complement appears to be that of attaching foreign organisms following the recognition by antibody. Thus, the HLA region appears to consist of three groups of genes, the A, B and C genes, the D gene and the complement genes. This arrangement of genes is found in many mammalian species as well.
|Original language||English (US)|
|Journal||Trends in Biochemical Sciences|
|State||Published - Jan 1 1978|
All Science Journal Classification (ASJC) codes
- Molecular Biology