Major histocompatibility complex, human chromosome

The human leucocyte antigen (HLA) system is the general name of a group of genes in the human major histocompatibility complex (MHC) region on human chromosome 6 (mouse chromosome 17) that encodes the cell-surface antigen-presenting proteins. 

Fig. 14.3 Tumor necrosis factor (TNF) locus with some of the polymorphic sites known within the TNF locus. C2, C4, complement C2, C4 Ch, chromosome HLA, human leukocyte antigen HSP, heat shock protein LTA, lymphotoxin A LTB, lymphotoxin B MHC, major histocompatibility complex. (Reproduced from ref 74 by permission of Future Medicine Ltd.)...

Fig. 8. Map of the human and mouse major histocompatibility complex (based on [212 and 143]). Only genes coding for class I and class II antigen-presenting molecules are shown. In contrast to the situation in humans, one of the mouse H-2 class I loci (K) is found separate from the others, on the opposite side of the class II region, probably as a result of an inversion of this region of chromosome 17.

Human leukocyte antigens are polymorphic cell-surface molecules that are intimately involved in the regulation of the immune response. The antigens are encoded by a series of closely linked genes known as the major histocompatibility complex (MHC), which is located on the short arm of chromosome 6 (BIO). The complex extends over approximately 4000 kilobases or 4 x 10 nucleotides and contains three distinct subregions known as class I, class II, and class III (T19) (see Fig. 1). 

Fig. 1. Schematic diagram of the major histocompatibility complex on human chromosome 6. Fully expressed genes are shown in black pseudogenes (which do not express a product) are shown in white and genes of undefined or uncertain status are shaded. Distances along the chromosome are measured in units known as kilobase pairs (kbp). BAT indicates B-associated transcript TNF, tumor necrosis factor. Adapted fiom Peter and Hawkins (P3) with permission, Copyright 1992, American Medical Association.

Volpi E.V., Chevret E., Jones T., Vatcheva R., Williamson J., Beck S., Campbell R.D., Goldsworthy M., Powis S.H., Ragoussis J., Trowsdale J., Sheer D. (2000). Large-scale chromatin organization of the major histocompatibility complex and other regions of human chromosome 6 and its response to interferon in interphase nuclei. J. Cell Sci. 113 1565-1576. 

Human leukocyte antigen (HLA). The major human histocompatibility complex situated on chromosome 6. Human HLA-A, -B, and -C (resembling mouse H2k, d, and 1) are MHC class I molecules, whereas HLA-DP, -DQ, and -DR (resembling mouse I-A and I-E) are MHC class II molecules. 

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