ABO blood group and related antigens, natural antibodies and transplantation.
The current success rate of transplant surgery and immunosuppression has led to a demand for organs that has outstripped the supply. This has required investigation of alternate strategies. Therefore, allotransplantation across the ABO blood group barrier has commenced, and pig-to-human xenotransplantation is under consideration. The first immunological barrier to both these types of transplantation is the prevention of the antibody-mediated rejection. This rejection is a result of natural preformed antibodies circulating in the serum of the recipient binding to either ABO (for allo) or alpha-galactose (alpha-Gal) (for xeno) antigens expressed on the donor tissue. These antibodies recognise antigens that are, in both cases, carbohydrate molecules with the characteristic feature that the nonreducing terminal carbohydrate is either a Gal or N-acetlygalactosamine residue in an alpha1,3 linkage. These epitopes are synthesised by closely related members of a single family of glycosyltransferases. This review discusses the carbohydrate antigens, the enzymes involved in their synthesis and the consequences of natural antibodies binding these antigens.
Milland
J
J
Department of Surgery (Austin Health), University of Melbourne, Box 5555, Heidelberg 3084, Australia.
Sandrin
M S
MS
D000017:ABO Blood-Group System / Q000737:chemistry / Q000276:immunology*; D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000276:immunology*; D002241:Carbohydrates / Q000276:immunology; D000939:Epitopes / Q000276:immunology; D005700:Galactosyltransferases / Q000032:analysis / Q000737:chemistry; D006084:Graft Rejection / Q000276:immunology*; D006801:Humans; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013552:Swine; D014183:Transplantation, Heterologous; D014184:Transplantation, Homologous
D000017:ABO Blood-Group System; D000906:Antibodies; D002241:Carbohydrates; D000939:Epitopes; D005700:Galactosyltransferases