Ir gene control of carrier recognition II. Unexpected low immunogenicity of guinea pig insulin

The immune response of mice to guinea pig insulin (as well as to insulins from other species) is controlled by immune response genes. The immunogenicity of guinea pig insulin is generally much lower than that of bovine insulin, through there are 14 sequence differences between mouse insulin and guinea pig insulin as compared to 5 sequence differences between mouse insulin and bovine insulin, respectively. The low immunogenicity of guinea pig insulin is indicated by a low frequency of responder strains and the requirement for high antigen doses for immunisation. Guinea pig and bovine insulin do not cross-react at the antibody level, but there seems to be some cross-recognition at the carrier level, as indicated by the capability of guinea pig insulin primed spleen cells to provide help for the pig insulin carrier in cooperative cell transfer.