The congenic mutant B6.C-H-2^bm-1 (H-2^bm-1) serological response to the T-cell receptor on EL4

Antisera reactive with the C57B1 lymphoma EL4 were induced by hyperimmunization of B6.C-H-2^bm-1 (H-2^bm-1) mice, a congenic mutant strain of C57B1/6 (B6). Molecular weight determinations of EL4 surface structures detected with the congenic mutant antibodies were accomplished by electrophoretic analyses (one and two dimensions) on sodium dodecyl sulfatepolyacrylamide gels (SDS-PAGE). Analysis of immunoprecipitates in the first dimension under reducing conditions revealed protein bands corresponding to gp 70 and its 33-kDa cleavage fragment, and two-three bands (40-45 kDa) that overlapped with those precipitated from EL4 with AS 8177, an antiserum which detects framework determinants on the T-cell heterodimeric receptor. Further analysis by diagonal electrophoresis confirmed identity of the 40- to 45-kDa proteins precipitated from EL4 with either AS 8177 or H-2^bm- anti-EL4 sera. Additional diagonal electrophoretic studies showed that the congenic mutant antibodies do not precipitate T-cell receptor molecules from C6VL, an in vitro line derived from the C6XL T-cell lymphoma of C57Bl/ka origin, which was previously shown by some of us to express the heterodimeric T-cell receptor. Together these results demonstrate detection of the heterodimeric T-cell receptor on EL4 with congenic mutant antibodies directed against nonconstant region determinant(s), and indicate a possible linkage between MHC haplotype and the immune response to intraspecies variable regions of the T-cell receptor.