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 CTL49, 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.