Phenotypical heterogeneity among human T cell receptor gamma/delta-expressing clones derived from peripheral blood

Human T cell clones expressing the T cell receptor (TcR) gamma/delta were isolated from peripheral blood lymphocytes of two unrelated donors. The TcR gamma/delta+ clones derived from one of these donors were all of the Ti gamma A+, delta-TCS1-, BB3+ phenotype indicating the exclusive use of the V gamma 9 and V delta 3 gene segments. In contrast, the T cell clones derived from the second donor were either Ti gamma A+, delta-TCS1-, BB3+:Ti gamma A-, delta-TCS1+, BB3- or Ti gamma A-, delta-TCS1-, BB3-. The delta-TCS1 determinant was expressed on both nondisulfide- and disulfide-linked TcR gamma/delta. Northern blot and DNA sequence analysis indicated that the Ti gamma A-, delta-TCS1-, BB3- clones do use the V delta 1 gene segment demonstrating that the delta-TCS1 monoclonal antibody does not react with all TcR gamma/delta using this particular gene segment. In contrast to the delta-TCS1+ T cell clones, the V delta 1+ delta-TCS1- T cell clones were found to express V delta 1 in conjunction with the J delta 3 gene segment suggesting that this particular V delta 1-J delta 3 combination is not recognized by the delta-TCS1 monoclonal antibody. In T cell clones derived from one individual the V delta 1 gene segment was found to be expressed with either J delta 1, J delta 2 or J delta 3. Heterogeneity among the 18 clones was detected with respect to the expression of the CD4, CD5 and CD8 antigens: one clone was CD4+, nine clones were CD5+ and two clones were CD8+. Thus, in this panel of clones, heterogeneity exists both with regard to CD antigen expression and the TcR gamma/delta phenotype. Also, our results indicate that the delta-TCS1 monoclonal antibody does not react with all TcR gamma/delta using the V delta 1 gene segment.