Phosphatidylinositol-3-kinase p110 delta differentially restrains and directs naïve versus effector CD8+ T cell transcriptional programs

Phosphatidylinositol-3-kinase p110 delta (PI3Kp110δ) is pivotal for CD8+ T cell immune responses. To inform how PI3Kp110δ regulates CD8+ T cells, the current study focuses on PI3Kp110δ controlled transcriptional programs and reveals how PI3Kp110δ selectively induces and represses expression of key genes that create a cytotoxic T cell (CTL). The data identify differences in PI3Kp110δ regulated transcriptional programs between naïve and cytotoxic T cells including differential control of cytolytic effector molecules, costimulatory receptors and the critical inhibitory receptors CTLA4 and SLAMF6. However, common to both naïve and effector cells is PI3Kp110δ control of the production of chemokines and cytokines that orchestrate communication between the adaptive and innate immune system. The study provides a comprehensive resource for understanding how PI3Kp110δ uses multiple mechanisms dependent on Protein Kinase B/AKT, FOXO1 dependent and independent mechanisms and mitogen-activated protein kinases (MAPK) to direct CD8+ T cell fate.