Genetic control of a shared idiotype among antibodies directed to distinct specificities

We developed an idiotypic radioimmunoassay system that detects shared idiotypic determinants, termed GTGL idiotype, on antibodies bearing distinct antigen-binding specificities in various mouse strains. Either poly-(Glu, Tyr) (GT)- or poly-(Glu, Lys) (GL)-related determinants are able to induce anti-GT and anti-GL (GTGL)-idiotypic antibodies. Strain distribution studies indicate that GTGL-idiotypic antibodies are readily induced and frequently expressed in antisera obtained from 25 different mouse strains immunized either with GT-related or GL-related polymers. The ability to express GTGL-idiotypic antibodies is a dominant trait and is controlled by Igh-linked gene(s). In addition, we demonstrated that in anticopolymer of L-glutamine acid60- L-alanine30-L- tyrosine (GAT) and anticopolymer of L-glutamic acid54-L-lysine35-L- phenylalanine11(GLphi) antisera, both antibodies uniquely specific to GAT or GLphi, respectively, and antibodies bearing dual specificities for GAT and GLphi, expressed GTGL idiotype. The genetic implications of these findings are discussed. X