Metabolic signaling directs the reciprocal lineage decisions of alpha beta and gamma delta T cells

The interaction between extrinsic factors and intrinsic signal strength governs thymocyte development, but mechanisms linking them remain elusive. We report that mTORC1 couples microenvironmental cues with metabolic programs in orchestrating reciprocal development of two fundamentally distinct lineages, alpha beta and gamma delta T cells. Loss of mTORC1 impairs alpha beta but promotes gamma delta T cell development, and disrupts metabolic remodeling of oxidative and glycolytic metabolism. Mechanistically, reactive oxygen species (ROS) controlled by mTORC1 serves as a key metabolic signal, and perturbation of redox homeostasis impinges upon fate decisions. Furthermore, single cell RNA sequencing and genetic dissection reveal that mTORC1 links developmental signals from T cell receptors and NOTCH to coordinate metabolic activity and signal strength. Our results establish mTORC1-driven metabolic signaling as a fundamental mechanism underlying thymocyte lineage choices. We used microarrays to compare the global transcription profiles of WT and Raptor-null cell populations in DN3a developing thymocytes, immature single-positive (ISP) T-cells, and gamma delta T-cells In total 19 samples were analyzed: DN3a thymocytes (WT, n = 3; Rptor-/-, n = 3); ISP T-cells (WT, n = 4; Rptor-/-, n = 3); gamma delta T-cells (WT, n = 3; Rptor-/-, n = 3);