γ/δ T cells account for up to ten percent of T lymphocytes in the peripheral blood of healthy donors. They can be activated by cytokines like interleukin(IL)-2 and IL-15, express natural killer (NK) cell markers such as NKG2D and show cytotoxic activity against several tumor cells. Natural cytotoxicity receptors (NKp30, NKp44 and NKp46) have so far been regarded as specific NK receptors. Resting NK cells express NKp30 and NKp46 whereas NKp44 is expressed by activated NK cells only. To date, only two γ/δ T cell clones expressing NKp44 have been described. There is no description of polyclonal γ/δ T cells expressing natural cytotoxicity receptors.
The aim of the presented study was to evaluate the expression of activating NK cell markers including NKp30, NKp44 and NKp46 on isolated γ/δ T cells, since these may play a role in the cytotoxic activity of γ/δ T cells.