Structure, Function, and Biosynthesis of the Major Human Histocompatibility Antigens (HLA‐A and HLA‐B)

Summary In summary, the complete primary structure of one HLA antigen (HLA‐B7) has now been determined, and sufficient information is available about other HLA‐A and ‐B and H‐2 molecules to begin to assess the location of the variable regions within these molecules. It is these regions of the molecules which have evolved to give rise to the extensive polymorphism in human populations, and they most likely define functionally important regions of the molecule. Thus, this information may help us to elucidate the natural biological function of these molecules, as, for example, in the recognition of allogeneic or virally infected syngeneic cells by cytotoxic T cells. Some functional studies, using purified HLA‐A and ‐B antigens inserted in liposomes, have been initiated, and studies of the biosynthesis of these antigens are of great interest in their own right. Further, using cDNA probes, they are being extended to permit us ultimately to underScand the organization of the genes on the sixth human chromosome which encode HLA‐A and ‐B antigens. Finally, such probes may permit the rapid accumulation of sequence information, which would allow us to underScand more completely the structure of these extremely important cell surface molecules.