Association of H-2 types with genetic control of immune reponsiveness to IgG (gamma2a) allotypes in the mouse.

Immune responsiveness to IgG allotypes in the mouse was found to be controlled by an immune response gene Ir-IgG linked to the H-2 locus. This was demonstrated by the analysis of the immune response to BALB/c IgG (gamma2a) myeloma proteins in mice of various H-2 types from five different linkage groups of immunoglobulin heavy chains. Antisera were examined for antibodies to idiotypic (Fab) and allotypic (Fc) specificities. No immune response to BALB/c IgG myeloma proteins was found in mice with the same heavy-chain immunoglobulin linkage group as BALB/c but of different H-2 types. In mice with immunoglobulin heavy chains that are different than BALB/c, a high immune response to IgG myeloma proteins was found in H-2 types b, bc, p, r, s, and v; a low response in a, d, k, and q. The Ir-IgG gene is controlled by a dominant autosomal gene.