Differential exposure of epitopes on the human red cell antigen D (Rh).
The D polypeptide of the human Rh blood group system has a number of different epitopes on its surface. It is also known that there is considerable variation in the number of D antigen sites available to different human monoclonal anti-D antibodies. For instance, certain monoclonal antibodies recognise only a small number of sites on the red cell surface (about 9,000 sites/red cell on R1R2 cells) whereas other antibodies recognise a high number (about 20,000-30,000 sites/red cell). It has been found that cholesterol enrichment of the red cell membrane increases the number of sites available to those antibodies which recognize only a few sites but has no effect on those recognising many sites. The results are consistent with the view that access to some of the D epitopes is partially hindered by neighbouring molecules in the membrane and that alteration of the lipid content of the membrane changes it in such a way as to allow increased access to these obstructed epitopes.
Hughes-Jones
N C
NC
Department of Immunology, Institute of Animal Physiology and Genetic Research, AFRC Babraham, Cambridge, U.K.
Gorick
B D
BD
Brown
D
D
D000911:Antibodies, Monoclonal / Q000276:immunology; D001666:Binding Sites, Antibody / Q000276:immunology; D002784:Cholesterol / Q000494:pharmacology; D000939:Epitopes / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology*; D006801:Humans; D012204:Rh-Hr Blood-Group System / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D002784:Cholesterol