Abstract: The application provides T cell gene expression signatures that can be used to predict T cell therapy outcomes.

Abstract: Provided herein are methods and compositions for modulating T-cell activity by incubating a CD8 T cell with a signal 3 cytokine, such as IL-12. Incubation of naïve CD8 T cells, particularly, with a signal 3 cytokine can acquire long-lived memory associated gene expression characteristic of the stem cell memory subset of CD8 T cells. Further, incubation with signal 3 cytokines can induce changes to the epigenetic profile of naïve CD8 T cells that are more characteristic of bona fide Tscm cells than in vitro generated cells using traditional differentiation protocols. On account of epigenetic profiles being preserved during in vivo homeostasis, signal 3 cytokines such as IL-12 can be used to engineer a T cell population with the desired epigenetic profile that maintains effector functions and proliferative capacity.