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.

项目概要 mTOR 在整合来自免疫微环境的信号以调节 T 细胞方面发挥着关键作用我们已经能够证明结节性硬化症的激活、分化和功能。复合物 2 (TSC2) 蛋白在 T 细胞中调节 mTORC1 激活中发挥重要作用。 RasGap 蛋白可抑制 Rheb GTPase 的活性，进而激活 mTORC1。 T 细胞中 TSC2 的基因缺失会导致 mTORC1 活性增强，并显着增加 CD8+ T 细胞效应器功能然而，虽然 TSC2-/- T 细胞对病毒和肿瘤反应强烈，但它们的作用却不同。 Kass 实验室最近发现，持续的 mTORC1 活性会导致记忆 CD8+ T 细胞生成减少。在 TSC2 上发现了一个新的磷酸化位点，该位点调节心肌细胞中的 mTORC1 活性。该位点 (S1365) 的磷酸化会导致 mTORC1 信号传导的抑制。突变该位点 (SA)。导致 mTORC1 活性增加，并导致更严重的心脏病和死亡率或者，在此位点创建磷模拟物 (SE) 可以缓解压力过载 (PO) 压力。 mTORC1 活性并在压力超负荷时提供预防心力衰竭的保护。 TSC2 (S1365) 位点可能在调节 T 细胞中 mTORC1 活性方面发挥重要作用。初步研究表明，在 TCR 参与后，该位点确实被磷酸化。携带 SA 突变的 mTORC1 在非刺激条件下的活性没有改变（与 TSC2-/- 不同） T 细胞），但具有 SE 突变的 T 细胞在 TCR 参与时表现出显着增加的活性。相反，缺氧、低 pH 和低 pH 会显着诱导 TSC2 (S1365) 磷酸化。活性氧表明该途径在整合应激信号中发挥着关键作用为了调节 T 细胞的分化和功能，在这个项目中，我们试图定义和理解一种新颖的方法。以及 T 细胞中 mTORC1 调节的选择性机制该提案的总体目标是剖析。 TSC2 在 S1365 处的磷酸化调节 T 细胞中 mTORC1 激活的机制，以及从而选择性地调节 T 细胞的激活、分化和功能。提案我们的研究结果将有助于阐明 T 细胞中新颖且关键的 mTORC1 调节信号机制细胞，并对开发疫苗和设计更强大的 T 细胞以用于收养具有影响细胞疗法可能反过来导致预防和治疗的治疗策略的改进。感染以及癌症。