Suppressive activity of Vδ2 γδ T cells on αβ T cells is licensed by TCR signaling and correlates with signal strength.

Despite recent progress in the understanding of γδ T cells' roles and functions, their interaction with αβ T cells still remains to be elucidated. In this study, we sought to clarify what precisely endows peripheral Vδ2 T cells with immunosuppressive function on autologous αβ T cells. We found that negatively freshly isolated Vδ2 T cells do not exhibit suppressive behavior, even after stimulation with IL-12/IL-18/IL-15 or the sheer contact with butyrophilin-3A1-expressing tumor cell lines (U251 or SK-Mel-28).