Sharing of Ia antigens between species. IV. Interspecies cross-reactivity of monoclonal antibodies directed against polymorphic mouse Ia determinants.
The specificity of interspecies Ia cross-reactions has been analyzed by testing a panel of monoclonal antibodies (mAb) to mouse I-E and I-A antigens for reactivity with pig Ia antigens. Our earlier studies showed that mouse anti-I-E alloantisera recognized common determinants on Ia antigens of other species, whereas anti-I-A alloantisera showed much more limited cross-reactivity. These results were confirmed using a panel of 17 anti-I-E mAb, 10 of which were cytotoxic to pig cells. 2D gel electrophoretic analyses of precipitates with these mAb of 35S-labeled, NP40 solubilized pig cells revealed a limited set of protein spots that appeared to be identical to the subset of pig Ia antigens precipitated by A.TH anti-A.TL alloantiserum. Because the cross-reactive mouse sera were produced in mouse strains that do not express an I-E molecule (H-2b and H-2s), it was anticipated that the cross-reacting antibodies would be reactive with the monomorphic determinant of the I-E molecule, Ia.7. However, comparison of the reactivity of these mAb with pig cells and mouse cells revealed that the cross-reactivity on pig cells correlated not with Ia.7 but rather with detection of epitope(s) of the I-E molecule associated with inter-strain polymorphism. Anti-I-A cross-reactions were also detected, but were weaker and more limited. These findings may have implications for the evolution of Ia antigens in mammalian species.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000235:genetics / Q000276:immunology*; D003165:Complement System Proteins / Q000378:metabolism; D003429:Cross Reactions; D003602:Cytotoxicity, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000032:analysis / Q000276:immunology*; D006801:Humans; D051379:Mice; D008805:Mice, Inbred A; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D011110:Polymorphism, Genetic; D011817:Rabbits; D013045:Species Specificity; D013552:Swine; D013556:Swine, Miniature
D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D003165:Complement System Proteins