[Genetic control of the immune response to Streptococcus mutans, insulins and (T,G)-A--L in the rat].

The immune response to Streptococcus mutans antigen, (T,G)-A--L, bovine insulin (B.I.) and pork insulin (P.I.) in the rat was studied by the double antibody method and/or the in vitro antigen-induced lymphocyte proliferation assay. Results were revealed that over ten inbred strains of rats were divided into high and low responders against the each antigen. Two high responders to insulins, SDJ (RT1U) and BN (RT1n) strains of rats were appeared to recognize different antigenic determinant (s) on the insulin molecule. The results of linkage and segregation analyses in F1, F2, backcross and partially congenic progenies were as follows: The immune response genes, Ir-(T,G)-A--L and Ir-B.I., which controlled the high responsiveness against (T,G)-A--L and B.I., respectively, and the immune suppression gene, Is-B.I., which controlled the low responsiveness to B.I. could be assumed. Ir(T,G)-A--L, Ir-B.I. and Is-B.I. were closely linked to RT1, which is the major histocompatibility complex of the rat.