MTORC1 in Thymic Epithelial Cells Is Critical for Thymopoiesis, T-Cell Generation, and Temporal Control of ??T17 Development and TCR?/? Recombination.

ABSTRACT: Thymus is crucial for generation of a diverse repertoire of T cells essential for adaptive immunity. Although thymic epithelial cells (TECs) are crucial for thymopoiesis and T cell generation, how TEC development and function are controlled is poorly understood. We report here that mTOR complex 1 (mTORC1) in TECs plays critical roles in thymopoiesis and thymus function. Acute deletion of mTORC1 in adult mice caused severe thymic involution. TEC-specific deficiency of mTORC1 (mTORC1KO) impaired TEC maturation and function such as decreased expression of thymotropic chemokines, decreased medullary TEC to cortical TEC ratios, and altered thymic architecture, leading to severe thymic atrophy, reduced recruitment of early thymic progenitors, and impaired development of virtually all T-cell lineages. Strikingly, temporal control of IL-17-producing ??T (??T17) cell differentiation and TCRV?/? recombination in fetal thymus is lost in mTORC1KO thymus, leading to elevated ??T17 differentiation and rearranging of fetal specific TCRV?/? in adulthood. Thus, mTORC1 is central for TEC development/function and establishment of thymic environment for proper T cell development, and modulating mTORC1 activity can be a strategy for preventing thymic involution/atrophy.

SUBMITTER: Wang HX 

PROVIDER: S-EPMC4758703 | biostudies-literature | 2016 Feb

REPOSITORIES: biostudies-literature