Use of the V delta 1 variable region in the functional T-cell receptor alpha chain of a WT31+ cytotoxic T lymphocyte clone which specifically recognizes HLA-A2 molecule.

We report here the molecular characterization of the T-cell receptor (TCR) expressed by a human HLA-A2 specific cytotoxic T-cell clone named CTL 49. Flow cytometry analysis with a panel of anti-TCR antibodies revealed an OKT3+, WT31+, A13+, BB3-, TCR delta-, delta TCS1-, TCR gamma/delta 1-, OKT4-, and OKT8+ phenotype, suggesting that, in CTL 49, the V delta 1-encoded A13 epitope could be included in its alpha beta TCR. Northern blot analysis confirmed the presence of C alpha, C beta and V delta 1 specific transcripts while no hybridization signal was detected by a C delta specific probe. Polymerase chain reaction (PCR) amplification of the first strand cDNA from CTL 49 with TCR-specific primers and sequence analysis revealed that V delta 1 region is productively rearranged to J alpha and to C alpha regions. This alpha chain pairs with a beta chain composed of V beta 13.2/D beta/J beta 2.3/C beta 2 leading to the expression of a functional TCR complex. These results, in addition to providing further evidence for the sharing of V delta 1 by alpha/beta and gamma/delta TCR, indicate that an alpha/beta T-cell receptor which includes the V delta 1 variable region can be involved in alloreactive recognition.