An example of major histocompatibility complex-linked control of idiotypic interactions.

Normal euthymic mice, injected i.v. with low doses of syngeneic monoclonal antibodies carrying "recurrent" idiotypes, develop a specific increase in numbers of splenic IgM plaque-forming cells that are paratopically and idiotypically similar to the injected antibody. We have now studied the responsiveness to a C57BL/6 anti-dextran a(1 leads to 6) and BALB/c anti-TNP (trinitrophenyl) monoclonal antibodies in a variety of strains. It was found that such responses are controlled by two linkage groups, namely major histocompatibility complex (MHC) and Ig-1.