Rapamycin together with TGF-β1, IL-2 and IL-15 induces the generation of functional regulatory γδT cells from human peripheral blood mononuclear cells

Regulatory gamma delta T cell (gamma delta Treg) is a recently reported subset of gamma delta T cells characterized by both expressions of TCR gamma delta and Foxp3, with potential immunosuppressive functions. However, the further studies of gamma delta Treg are limited mainly due to its low quantities in vivo and the lack of methods to induce gamma delta Treg largely in vitro. Here we show that rapamycin together with TGF-beta 1, IL-2 and IL-15 can induce and expand gamma delta Tregs derived from human peripheral blood mononuclear cells efficiently in vitro. Thus-induced gamma delta Tregs express high levels of Foxp3 and CD25, and display significant immunosuppressive activities in vitro. (C) 2013 Elsevier B.V. All rights reserved.