title: Tuning mTOR activity for immune balance.
abstract: The mTOR pathway orchestrates diverse physiological processes, including T cell functions and fate decisions; however, the regulation of mTOR-dependent T cell differentiation remains elusive. In this issue, Park et al. examine the role of TSC1, an mTOR signaling regulator, in T cell differentiation and the balance between T cell-mediated immunity and tolerance. They found that enhanced mTOR activity in Tsc1-deficient T cells promotes Th1 and Th17 differentiation, leading to increased intestinal inflammation in murine colitis. Tsc1-deficient Tregs had impaired suppressive activity in inflammatory conditions. These defects were associated with the acquisition of effector-like phenotypes and could be further exacerbated by concomitant loss of transcription factor Foxo3. This study highlights that TSC1-mediated control of mTOR activity impinges on the balance between immunity and tolerance by dictating effector and regulatory T cell responses.
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.forename: Hongbo
authors.initials: H
authors.lastname: Chi
mesh_terms: D000818:Animals; D003092:Colitis / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D018417:Th1 Cells / Q000276:immunology*; D058504:Th17 Cells / Q000276:immunology*; D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins / Q000502:physiology*
chemical_list: D000077004:Tuberous Sclerosis Complex 1 Protein; D025521:Tumor Suppressor Proteins