MicroRNA-181a restricts human gamma delta T cell differentiation by targeting Map3k2 and Notch2

gamma delta T cells are a conserved population of lymphocytes that contributes to anti-tumor responses through its overt type 1 inflammatory and cytotoxic properties. We have previously shown that human gamma delta T cells acquire this profile upon stimulation with IL-2 or IL-15, in a differentiation process dependent on MAPK/ERK signaling. Here, we identify microRNA-181a as a key modulator of human gamma delta T cell differentiation. We observe that miR-181a is highly expressed in patients with prostate cancer and that this pattern associates with lower expression of NKG2D, a critical mediator of cancer surveillance. Interestingly, miR-181a expression negatively correlates with an activated type 1 effector profile obtained from in uitro differentiated gamma delta T cells and miR-181a overexpression restricts their levels of NKG2D and TNF-alpha. Upon in silico analysis, we identify two miR-181a candidate targets, Map3k2 and Notch2, which we validate uia overexpression coupled with luciferase assays. These results reveal a novel role for miR-181a as critical regulator of human gamma delta T cell differentiation and highlight its potential for manipulation of gamma delta T cells in next-generation immunotherapies.