Comparison of human and chimpanzee Kell blood group systems

Kell antigens on chimpanzee (Pan troglodytes) red cells were determined using specific human alloimmune and murine monoclonal antibodies. After avoidance of interspecies reactions, chimpanzee red cells were found to react with most Kell system antibodies. The chimpanzees had phenotypes similar to those of humans. The main difference was that all of 27 chimpanzee red cell samples tested were of the K:6, -7, phenotype, while in humans most are K:-6, 7. The most common chimpanzee Kell blood group phenotype was K:-1,2,-3,4,5,6,-7,11,12,13,14, 15,18,19,22. Murine monoclonal anti-K2 and -K14 immunoprecipitated a 97-kD protein from chimpanzee red cells and a 93-kD protein from human red cells. Enzymatic deglycosylation yielded proteins of about 79 kD for humans and 77 kD for chimpanzees. Both human and chimpanzee Kell proteins reacted equally well on Western blots with polyclonal rabbit antibody to human Kell protein, which indicated close homology.