The major histocompatibility complex of chimpanzees: identification of several new antigens controlled by the A and B loci of ChLa.

The serology and genetics of 17 serologically defined tissue antigens of chimpanzees is described. Analysis of their distribution in 200 unrelated chimpanzees and their segregation in a large number of chimp families suggests that 14 of the antigens are controlled by two closely linked loci: seven by the A and seven by the B locus of ChLA. Typing of chimpanzees with human alloantisera revealed that several of those A and B locus antigens of ChLA are the chimp's serological counterparts of A and B locus antigens of the human HLA system, respectively. One of the newly discovered chimp antigens may be defined by a "third series" of ChLA, most likely the chimp's analogue of the human HLA-C series. The probable existence of a ChLA-linked D locus of chimpanzees and similarities between D-locus and Ia-locus (DRw) antigens of chimpanzee and man, are also briefly discussed.