TET2 regulates early and late transitions in exhausted CD8 T cell differentiation and limits CAR T cell function.

CD8 T cell exhaustion hampers control of cancer and chronic infections and limits chimeric antigen receptor (CAR) T cell efficacy. Targeting in CAR T cells provides therapeutic benefit; however, TET2's role in exhausted T cell (T) development is unclear. In chronic lymphocytic choriomeningitis virus (LCMV) infection, TET2 drove conversion from stem cell-like T progenitors toward terminally differentiated and effector (T)-like T.