A gamma delta T cell specific surface receptor (WC1) signaling G0/G1 cell cycle arrest

Three monoclonal antibodies (mAb; SC-6, SC-12, and SC-29) reactive with the gammadelta T cell-restricted antigen WC1 were obtained immunizing mice with an ovine interleukin (IL)-2-dependent gammadelta T cell line. These mAb strongly inhibited DNA synthesis in IL-2-dependent gammadelta T cell lines with cell cycle arrest in G0/G1 phase, but did not induce apoptosis. The mAb-induced growth arrest was reversible, either by removing the mAb or by co-culture with mitogen or anti-CD3 in the presence of IL-2. In contrast, addition of phorbol ester, ionomycin and IL-2 had no effect on the mAb-induced growth arrest. The observations define a biologically important role for the cell surface molecule WC1 in the regulation of gammadelta T cell proliferation and also provide a suitable system to study the relevant signal transduction events.