Evolution of Major Histocompatibility Complex Polymorphisms and T‐Cell Receptor Diversity in Primates

The major histocompatibility complexes (Mhc) of chimpanzees and rhesus monkeys were discovered about two decades ago (Balner et al. 1971. 1974). Because of its relevance for transplantation, a detailed description of polymorphism of some chimpanzee and rhesus macaque Mhc class I and II loci was achieved by serological techniques (Table I). In those days, it was already apparent that the Mhc\ of humans and nonhuman primates shared many similar features. For example, cross-reactions of typing sera suggested that humans and chimpanzees possessed highly related alleles belonging to the HLA-AI/A3/AU lineage (Balner 1977). The self-sustaining nonhuman primate colonies at our institute have been pedigreed based on Mhc genetics and their outbred character has been carefully maintained for more than 20 years. This pioneering work of Hans Balner and colleagues has been fundamental to our current research program focusing on the biological role o[Mhc and Ttr gene products in relation to health and disease. The introduction of molecular and cellular techniques has extended our knowledge on the co-evolution of primate Mhc and Tcr systems as well as their complex array of interactions. The next paragraphs arc devoted to a review of the results that we and our colleagues have obtained in recent years.