Tentative model for the mapping of D epitopes on the RhD polypeptide.
The partial D phenotypes correspond to D-positive individuals that may develop anti-D antibodies following immunization by transfusion or pregnancy, since they lack some of the D epitopes that compose the D antigen. When these red cells are tested with a panel of human monoclonal anti-D, different patterns of reactivity are observed and at least nine distinct epitopes termed epD1 to epD9 can be identified. Molecular analysis of partial D variants have shown that the loss of some D epitopes is associated either with intergenic recombination events between the D and CE genes generating hybrid gene structures D-CE-D or CE-D-CE, or with point mutations of the D gene. Based on these findings, a tentative model that correlates critical amino acid positions and D epitope expression on the D protein was proposed. Although recent studies suggest that the D antigen may be composed of as many as 30 epitopes, the relatively simple model presented here may be useful to serologists as a preliminary approach to understanding the basis of D antigenic variation in terms of structure-activity relationship.
Cartron
J P
JP
INSERM U76, Institut National de Transfusion Sanguine, Paris, France.
Rouillac
C
C
Le Van Kim
C
C
Mouro
I
I
Colin
Y
Y
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006801:Humans; D008958:Models, Molecular; D010455:Peptides; D010641:Phenotype; D012204:Rh-Hr Blood-Group System / Q000235:genetics* / Q000276:immunology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D010455:Peptides; D012204:Rh-Hr Blood-Group System