Gene expression profiling of Tc1 and Tc17 CD8+ T cells

CD8+ T cells are pre-programmed for cytotoxic differentiation. However, a subset of effector CD8+ T cells (‘Tc17’) produce IL-17 and fail to express cytotoxic genes. Here, we show that the transcription factors directing IL-17 production inhibit cytotoxicity despite persistent Runx3 expression. Cytotoxic gene repression did not require the transcription factor Thpok. We further show that STAT3 restrained cytotoxic gene expression in CD8+ T cells and that RORgt represses cytotoxic genes by inhibiting the functions but not the expression of the ‘cytotoxic’ transcription factors T-bet and Eomesodermin. Thus, the transcriptional circuitry directing IL-17 expression inhibits cytotoxic functions. Naïve CD8+ T cells were sorted and activated for 4 days in the presence of IL-12 (Tc1) or IL-6 and TGFb (Tc17)