Phosphorylation of TSC2 (S1365) as a novel Regulator of mTORC1 Signaling in T Cells

TSC2 (S1365) 磷酸化作为 T 细胞中 mTORC1 信号转导的新型调节剂

基本信息

批准号：
10596567
负责人：
Erika L Pearce
金额：
$ 51.17万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-04-08 至 2026-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10596567
关键词：
Adoptive Cell Transfers Attenuated CD8-Positive T-Lymphocytes CD8B1 gene Cardiac Myocytes Cell Differentiation process Cell physiology Cellular biology Cues Cyclic GMP-Dependent Protein Kinases Development Effector Cell Engineering Exhibits FRAP1 gene Generations Genetic Goals Guanosine Triphosphate Phosphohydrolases Heart Heart Diseases Heart failure Helper-Inducer T-Lymphocyte Heterozygote Human Hyperactivity Hypoxia Immune signaling Infection Knock-in Mouse Malignant Neoplasms Memory Metabolic Mus Mutate Mutation Outcome Pathway interactions Phenotype Phosphorylation Phosphorylation Site Play Protein-Serine-Threonine Kinases Proteins Reactive Oxygen Species Regulation Rest Role Serine Signal Pathway Signal Transduction Site Stress T cell differentiation T-Cell Activation T-Cell Receptor T-Lymphocyte Testing Tuberous Sclerosis Virus cancer immunotherapy effector T cell improved in vivo insight mimetics mortality mutant novel pressure prevent ras GTPase-Activating Proteins treatment strategy tumor tumor-immune system interactions vaccine development

项目摘要

PROJECT SUMMARY mTOR plays a critical role in integrating signals from the immune microenvironment to regulate T cell activation, differentiation and function. We have been able to demonstrate that the Tuberous Sclerosis Complex 2 (TSC2) protein plays an important role in regulating mTORC1 activation in T cells. TSC2 is a RasGap protein that inhibits the activity of Rheb GTPase that in turn activates mTORC1. We have shown that genetic deletion of TSC2 in T cells leads to enhanced mTORC1 activity and a marked increase in CD8+ T cell effector function. However, while TSC2-/- T cells respond robustly to viruses and tumors, their persistent mTORC1 activity leads to a decrease in memory CD8+ T cell generation. Recently, the Kass lab has identified a novel phosphorylation site on TSC2 that regulates mTORC1 activity in cardiac myocytes. Phosphorylation of this site (S1365) leads to the inhibition of mTORC1 signaling. Mutating this site(SA) leads to an increase mTORC1 activity and the development of worse heart disease and mortality from pressure-overload (PO) stress. Alternatively, creating a phosphomimetic (SE) at this site mitigates mTORC1 activity and imparts protection from heart failure upon pressure overload. We hypothesized that the TSC2 (S1365) site might play an important role in regulating mTORC1 activity in T cells. Our preliminary studies demonstrate that upon TCR engagement this site is indeed phosphorylated. T cells harboring the SA mutation have unaltered mTORC1 activity in the non-stimulated condition (unlike TSC2-/- T cells), but show markedly increased activity upon TCR engagement. T cells with the SE mutation exhibit the opposite. Furthermore, phosphorylation of TSC2 (S1365) is markedly induced by hypoxia, low pH and reactive oxygen species suggesting that this pathway plays a critical role in integrating stress signals in order to regulate T cell differentiation and function. In this project we seek to define and understand a novel and selective mechanism of mTORC1 regulation in T cells. The overall goal of this proposal is to dissect the mechanisms by which phosphorylation of TSC2 at S1365 regulates mTORC1 activation in T cells, and consequently selectively regulates T cell activation, differentiation and function. Upon the completion of this proposal our findings will help elucidate novel and critical mTORC1 regulatory signaling mechanisms in T cells, and have implications for developing vaccines and engineering more robust T cells for Adoptive Cellular Therapy. This may in turn result in improved treatment strategies for preventing and treating infections as well as cancer.

项目摘要 mTOR在整合来自免疫微环境的信号以调节T细胞的信号中起关键作用激活，分化和功能。我们已经能够证明结节硬化症复合物2（TSC2）蛋白在调节T细胞中MTORC1激活中起重要作用。 TSC2是a RASGAP蛋白抑制Rheb GTPase的活性，而Rheb GTPase又激活MTORC1。我们已经显示了 T细胞中TSC2的遗传缺失导致MTORC1活性增强，并显着增加 CD8+ T细胞效应子函数。但是，虽然TSC2 - / - T细胞对病毒和肿瘤的反应强烈持续的MTORC1活性导致记忆CD8+ T细胞产生的减少。最近，卡斯实验室已经确定了TSC2上新型的磷酸化位点，该位点调节心肌细胞中MTORC1活性。该位点的磷酸化（S1365）导致MTORC1信号的抑制。突变此站点（SA）导致MTORC1活性的增加，并从压力超负荷（PO）应力。另外，在此站点上创建磷酸化（SE）会减轻 MTORC1活性并在压力超负荷时赋予心力衰竭的保护。我们假设了这一点 TSC2（S1365）位点可能在调节T细胞中MTORC1活性中起重要作用。我们的初步研究表明，在TCR参与时，该部位确实被磷酸化。 T细胞携带SA突变的MTORC1活性在未刺激的条件下（与TSC2 - / - 不同） T细胞），但在TCR参与后显示出明显增加的活性。具有SE突变出口的T细胞相反。此外，TSC2（S1365）的磷酸化显着诱导了缺氧，低pH和活性氧表明该途径在整合应力信号中起着至关重要的作用为了调节T细胞分化和功能。在这个项目中，我们试图定义和理解一本小说和T细胞中MTORC1调控的选择性机制。该提议的总体目标是剖析 S1365在S1365上的光谱化调节MTORC1激活TSC2的机制，以及因此，选择性调节T细胞激活，分化和功能。完成此完成建议我们的发现将有助于阐明t中的新颖和关键MTORC1调节信号传导机制细胞，并对开发疫苗和工程的影响更大，对收养的T细胞具有更强的T细胞细胞疗法。反过来，这可能会改善预防和治疗的治疗策略感染和癌症。