HLA Complex—Associations with Disease

Abstract

Throughout the vertebrate series, one particular segment of the chromosome carries the genes for a group of glycoproteins which have the general property of being able to attach to various membrane structures. The genes which contain the genetic information for these membrane proteins are housed within a relatively small portion of the chromosomes, probably in the order of one-tenth of a percent of the total genome. Despite this small genomic representation, the gene products of this particular region play important roles in transplantation rejection, in various cell-cell interactions and, the subject of this review, susceptibility or resistance to various diseases. The region was first recognized because of its production of glycoproteins important in transplant rejection reactions, and because serological techniques were developed to type these antigens, termed histocompatibility antigens, this region in the various species of vertebrates has become known as the major histocompatibility complex (MHC). The adjective major was added because this region, above all others, gave the strongest reactions, both in terms of transplantation rejection and in terms of various in vitro phenomena which are considered to be correlates of these strong rejection reactions or considered to define antigens directly involved in these transplantation rejections.