Identification of chimpanzee leukocyte antigens (ChL-A) and their relation to HL-A

The identification of a number of leukocyte antigens of chimpanzees is described. Suggestive evidence was obtained that some of the isoantisera recognize specificities of a hypothetical genetic system of chimpanzee antigens which, in analogy with the human HL-A system, is tentatively called ChL-A. We demonstrated the similarity of several ChL-A specificities with human antigens of the HL-A system by typing chimpanzee cells with monospecific human sera and human cells with chimpanzee isoantisera. Several chimpanzee sera contained antibodies of distinct HL-A specificity when used for human tissue typing (HL-A1, 7, and 11); antigens 4a and 4b appear to be distributed in an alternate fashion, also, on cells of unrelated chimpanzees