Phenotypical heterogeneity among human T cell receptor y/&expressing clones derived from peripheral blood
Human Tcell clones expressing the Tcell receptor (TcR) y/6 were isolated from peripheral blood lymphocytes of two unrelated donors. The TcR y/6+ clones derived from one of these donors were all of the TiyA+, 6-TCS1-, BB3+ phenotype indicating the exclusive use of the V,9 and Vb3 gene segments. In contrast, the Tcell clones derived from the second donor were either TiyA+, 6-TCSl-, BB3+;TiyA-, 6-TCS1+, BB3-orTiyA-, 6-TCS1-, BB3-.The 6-TCS1 determinant was expressed on both nondisulfideand disulfide-linked TcR ylb. Northern blot and DNA sequence analysis indicated that the TiyA-, 6-TCS1-, BB3clones do use the Vbl gene segment demonstrating that the 6-TCS1 monoclonal antibody does not react with all TcRy/6 using this particular gene segment. In contrast to the 6-TCS1+ Tcell clones, theVbl+ 6-TCS1-Tcell clones were found to express Vbl in conjunction with the 563 gene segment suggesting that this particular Vbl-Jb3 combination is not recognized by the 6-TCS1 monoclonal antibody. I n Tcell clones derived from one individual the Vbl gene segment was found to be expressed with either Jb1, Jb2 or Jb3. 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 theTcRy/6 phenotype. Also, our results indicate that the 6-TCS1 monoclonal antibody does not react with all TcRy/6 using the Vbl gene segment.