The histocompatibility-2 system in wild mice. XII. An immunochemical analysis of the anti-ia antibodies in antisera produced against 13 B10.W lines

The I-region products of 13 congenic B10.W lines carrying wild-derived H-2 haplotypes were analyzed with antiB10.W alloantisera. The alloantisera were tested for immunoprecipitating activity with radiolabeled glycoproteins of the immunizing donors. Eleven of the 13 alloantisera immunoprecipitated glycoproteins with SDS-PAGE mobilities consistent with m.w. of 45,000, 35,000, and 26,000. The 35,000 and 26,000 products were identified as the Ia antigens of the B10.W lines. The specificity of the anti-Ia antibodies in each anti-B10.W alloantiserum was assessed by panel testing and absorption analysis with a panel of 26 glycoprotein fractions that were prepared from 11 inbred lines and 15 B10.W lines. Four new Ia antigens that are only present in the B10.W lines were detected in this analysis. The I-region products of 8 of the B10.W lines were serologically indistinguishable from those found among laboratory inbred strains. The implications of these findings for I-region polymorphisms are discussed.