Diversity of anti-HLA-DR antibodies elicited by distinct anti-idiotypic monoclonal antibodies recognizing idiotopes co-expressed by the immunizing monoclonal antibody.
Analysis at the clonal level of the idiotypic network has identified differences in fine specificity between antigen-binding anti-anti-idiotypic (anti-anti-id) monoclonal antibody (mAb) and the original mAb as well as among antigen-binding anti-anti-idiotypic (anti-id) mAb. However, the diversity of humoral immune responses elicited by anti-id mAb recognizing idiotopes co-expressed on the immunizing mAb has not been analysed. Since this information may contribute to our understanding of the role of anti-id antibodies in the generation of diversity in the course of an immune response, we have compared the fine specificity and idiotype profile of two subsets of anti-HLA-DR mAb generated with the anti-id mAb F5-444 and F5-830. The latter mAb recognize idiotopes co-expressed in the antigen-combining site of the immunizing anti-HLA-DR1,4,w14,w8,9 mAb AC1.59. These investigations showed that: (1) the two subsets of anti-HLA-DR mAb overlap only partially in their reactivity patterns with HLA-DR+ cells; (2) both subsets of anti-HLA-DR mAb recognize spatially close epitopes; (3) each subset of anti-HLA-DR mAb has unique reactivity patterns with soluble HLA-DRw16 and DRw17 antigens; and (4) each subset of anti-anti-id mAb displays a distinct idiotype profile. The subtle differences in the fine specificity and idiotype profile of the two subsets of anti-HLA-DR mAb suggest that anti-id antibodies may play a role in the generation of diversity in the course of a humoral immune response.
Mariani
S M
SM
Department of Microbiology and Immunology, New York Medical College, Valhalla 10595.
Armandola
E A
EA
Ferrone
S
S
D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000916:Antibody Diversity / Q000276:immunology*; D002460:Cell Line; D004306:Dose-Response Relationship, Immunologic; D000939:Epitopes / Q000032:analysis; D006684:HLA-DR Antigens / Q000276:immunology*; D006801:Humans; D007130:Immunoglobulin Idiotypes / Q000276:immunology
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D000939:Epitopes; D006684:HLA-DR Antigens; D007130:Immunoglobulin Idiotypes