Binding characteristics of human hybridoma IgG and IgM rheumatoid factors: influence of IgG isotype and carbohydrate content.
The interaction of human monoclonal rheumatoid factors (RF) with the Fc portion of IgG is complex. We have investigated the influence of the nature of the antigen (Fc) on the binding of hybridoma-generated RF derived from patients with rheumatoid arthritis or systemic lupus erythematosus. For IgM RF, the interaction is strongly influenced by the primary structure of the Fc with little or no effect of the carbohydrate, which is positioned at amino acid 297 in the gamma-2 domain. In contrast, our preliminary data suggest that IgG RF binding is affected both by the primary structure and the nature of the carbohydrate of the Fc. These results suggest that the antigen selection events which lead to the induction and production of IgG RF are likely to be different from those that induce IgM RF production.
Newkirk
M M
MM
Department of Medicine, McGill University, Montreal General Hospital Research Institute, Quebec, Canada.
Rauch
J
J
Commerford
K
K
D050260:Carbohydrate Metabolism; D006801:Humans; D006825:Hybridomas / Q000378:metabolism*; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism*; D007132:Immunoglobulin Isotypes / Q000502:physiology; D007075:Immunoglobulin M / Q000378:metabolism*; D012217:Rheumatoid Factor / Q000378:metabolism*
D007141:Immunoglobulin Fc Fragments; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D012217:Rheumatoid Factor