H-2Ld-alloreactive T cell hybridomas utilize diverse V alpha and V beta T cell receptor chains

We have sequenced the TCRs from Ld-specific alloreactive T cell hybridomas, whose reactivities we have found to be quite representative of those of a primary dm2 anti-BALB/cJ mixed lymphocyte reaction. We find V beta 6, V beta 7, V beta 8 and V beta 10 gene segments. V alpha usage is diverse, although closely related to that from peptide-specific Ld-restricted CTLs. V alpha-V beta selection provides evidence of preferential pairing. Amino acid frequency analysis shows that the alpha CDR2 region is rich in charged amino acids, in contrast to the beta CDR2 region. Our data suggests the beta chain may be more immunoglobulin-like than the alpha chain, and that charge complementarity may be important in TCR-MHC interactions. We do not consider our results to be contradictory to those previously reported but rather they may represent an early, more diverse response.