RESTRICTION OF THE T-CELL RECEPTOR V-DELTA-GENE REPERTOIRE IS DUE TO PREFERENTIAL REARRANGEMENT AND IS INDEPENDENT OF ANTIGEN SELECTION

To determine whether the limited V gene usage by the T-cell receptor d elta (TCRD) chain is dictated by preferential rearrangement or by anti gen selection, we characterized and compared the TCRDV gene repertoire of the productive with that of the unproductive allele in 80 human TC RG/TCRD clones. Six different V genes were found on the expressed alle le; two of them, provisionally named DV7 and DV8, have not been descri bed before on the surface of TCRG/TCRD T cells. Overall, six V genes a nd six non-V elements were isolated from the unproductive allele. Inte restingly, the same set of genes was rearranged both in the productive and in the unproductive chromosome. These findings seem to suggest th at antigen-independent mechanisms play a major role in the restriction of the TCRDV gene repertoire.