School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.
J Exp Med. 2012 Dec 17;209(13):2441-53. doi: 10.1084/jem.20112607. Epub 2012 Nov 26.
mTORC1 (mammalian target of rapamycin complex 1) controls transcriptional programs that determine CD8+ cytolytic T cell (CTL) fate. In some cell systems, mTORC1 couples phosphatidylinositol-3 kinase (PI3K) and Akt to the control of glucose uptake and glycolysis. However, PI3K-Akt-independent mechanisms control glucose metabolism in CD8+ T cells, and the role of mTORC1 has not been explored. The present study now demonstrates that mTORC1 activity in CD8+ T cells is not dependent on PI3K or Akt but is critical to sustain glucose uptake and glycolysis in CD8+ T cells. We also show that PI3K- and Akt-independent pathways mediated by mTORC1 regulate the expression of HIF1 (hypoxia-inducible factor 1) transcription factor complex. This mTORC1-HIF1 pathway is required to sustain glucose metabolism and glycolysis in effector CTLs and strikingly functions to couple mTORC1 to a diverse transcriptional program that controls expression of glucose transporters, multiple rate-limiting glycolytic enzymes, cytolytic effector molecules, and essential chemokine and adhesion receptors that regulate T cell trafficking. These data reveal a fundamental mechanism linking nutrient and oxygen sensing to transcriptional control of CD8+ T cell differentiation.
mTORC1(哺乳动物雷帕霉素靶蛋白复合物 1)控制着决定 CD8+细胞毒性 T 细胞(CTL)命运的转录程序。在某些细胞系统中,mTORC1 将磷酸肌醇-3 激酶(PI3K)和 Akt 偶联起来,控制葡萄糖摄取和糖酵解。然而,PI3K-Akt 非依赖性机制控制 CD8+T 细胞中的葡萄糖代谢,而 mTORC1 的作用尚未得到探索。本研究现在表明,CD8+T 细胞中的 mTORC1 活性不依赖于 PI3K 或 Akt,但对于维持 CD8+T 细胞中的葡萄糖摄取和糖酵解至关重要。我们还表明,由 mTORC1 介导的 PI3K 和 Akt 非依赖性途径调节 HIF1(缺氧诱导因子 1)转录因子复合物的表达。这种 mTORC1-HIF1 途径对于维持效应 CTL 中的葡萄糖代谢和糖酵解是必需的,并且显著地将 mTORC1 与控制葡萄糖转运蛋白、多种限速糖酵解酶、细胞毒性效应分子以及调节 T 细胞迁移的必需趋化因子和粘附受体表达的多样化转录程序偶联起来。这些数据揭示了一种将营养和氧气感应与 CD8+T 细胞分化的转录控制联系起来的基本机制。