Inhibition of dual Ir gene-controlled T-lymphocyte proliferative response to poly(Glu⁵⁶Lys³⁵Phe⁹)(n) with anti-Ia antisera directed against products of either I-A or I-C subregion

Previous studies have demonstrated that both the antibody and T-lymphocyte proliferative immune responses to poly(Glu⁵³Lys³⁶Phe¹¹)(n) (GLΦ) are under the control of two major histocompatibility-linked immune response (Ir) genes. One gene, termed Ir-GLΦ-α, has been mapped to the I-C or I-E subregion of the major histocompatibility complex, while the other, termed Ir-CLΦ-β, has been mapped to the I-A subregion. In this paper we examine the effect of anti-I-region-associated (Ia) antisera on the T-lymphocyte proliferative response to GLΦ. Antibodies directed against Ia antigens coded for by genes in either the I-A or I-C subregion were found to inhibit the proliferative response to GLΦ. These results suggest that a function mediated by two Ir gene products can be blocked by anti-Ia antisera directed against either one, and thus, that both products are expressed on the cell surface.