Idiotypes and allotypes on Ia-binding alloactivated Lyt-1+,2-,3- T cells are coded for by genes linked to the igh-1 allotype locus.

Xenogeneic antisera, designated 5936 and 6036, have been used in this laboratory to define 5936-idiotypes (Id) and 6036-T cell receptor (Tcr) allotype determinants, respectively, on populations of B6 anti-CBA MLC T blasts. The present experiments were carried out to determine a) whether T lymphocytes that bear 5936-Id also express antiserum 6036-defined Tcr allotypes; b) if so, what is the Lyt phenotype and c) specificity of this T lymphocyte population, and d) whether the genes coding for 5936-Id and 6036-allotypes are linked to immunoglobulin (Ig) allotype genes. The results showed that 5936-Id-bearing T lymphocytes were included in a subset of cells that expressed antiserum 6036-defined Tcr allotypic determinants and the Lyt-1+,2-,3- phenotype. By genetic segregation analysis it was shown that both 5936-Id and antiserum 6036-defined allotypic determinants on T cells were linked to Igh-1b allotypes. 5936-Id determinants were expressed on T lymphocytes of Igh-1b allotype strains, specific for allogeneic I-Ak but not on those specific for I-Ak/Ek molecules. In contrast, 6036-Tcr allotype determinants were present on T lymphocytes from Igh-1b allotype strains, specific for either I-Ak or I-Ak/Ek molecules. The results support the hypothesis that 5936-Id determinants are present only on a subset of anti-I-Ak T cell receptors, whereas 6036-Tcr allotype determinants are shared among T cell receptors of several unrelated specificities from Igh-1b allotype-bearing strains.