Uncovering the metabolic underpinnings of T cell exhaustion

揭示 T 细胞耗竭的代谢基础

• 批准号: 10707255
• 负责人: Greg M. Delgoffe
• 金额: $ 64.04万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-19 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10707255
• 关键词: Acetyl Coenzyme A; Acetylcysteine; Aconitate Hydratase; Antigens; Antioxidants; Atrophic; Biology; Blocking Antibodies; Cell physiology; Cells; Cellular biology; Characteristics; Chronic; Citrates; Citric Acid Cycle; Cytosol; Data; Environment; Exposure to; Fatty Acids; Functional disorder; Genes; Genetic; Genetic Transcription; Glucose; Hypoxia; Immune; Immunity; Immunosuppression; Immunotherapy; In Vitro; Knockout Mice; Lipids; Lipolysis; Malignant Neoplasms; Mediating; Metabolic; Metabolic stress; Metabolism; Mitochondria; Modality; Modeling; Monoclonal Antibodies; Nutrient; Obesity; Oxidative Stress; Oxygen; PD-1 blockade; Pathway interactions; Patients; Peroxides; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotyrosine; Play; Predisposition; Production; Protein Tyrosine Phosphatase; Proteome; Proteomics; Reactive Oxygen Species; Regulatory T-Lymphocyte; Reporting; Repression; Role; Signal Transduction; Source; Stress; T cell differentiation; T-Lymphocyte; Technology; Tissues; Tumor Immunity; Up-Regulation; Weight; anti-cancer; anti-tumor immune response; biological adaptation to stress; conditional knockout; cytokine; cytotoxic; cytotoxicity; design; exhaust; exhaustion; fatty acid oxidation; glucose uptake; immune cell infiltrate; improved; in vivo; inhibitor; lipid biosynthesis; member; mitochondrial dysfunction; neoplastic cell; novel; novel therapeutics; nutrient deprivation; overexpression; patient subsets; pharmacologic; prevent; progenitor; programmed cell death protein 1; programs; response; self-renewal; success; transcriptomics; tumor eradication; tumor growth; uptake

PROJECT SUMMARY/ABSTRACT The successes of immunotherapies like blockade of co-inhibitory `checkpoint' molecules have changed the treatment paradigm of cancer. However, the fact that robust responses are restricted to a subset of patients highlights the need to further understand the biology of exhausted T cells: what drives their differentiation, maintains their dysfunction, and how they may be reinvigorated to eradicate tumor cells. Our lab and others have revealed that metabolic stress and mitochondrial dysfunction are key drivers in T cell exhaustion, both from a cell extrinsic and cell intrinsic perspective. We recently reported that mitochondrial stress and reactive oxygen species (ROS) production, driven to intolerable levels under hypoxic environments in the face of persistent antigen, was sufficient to deviate cells into a terminally exhausted fate. Antioxidants both pharmacologic and genetic could bias T cell differentiation away from exhaustion to more functional fates. But precisely how ROS production alters T cell fate and function remains unclear. One of the more intriguing observations was elevating ROS via mitochondrial dysfunction altered T cell signaling: as peroxide is one of the more potent inhibitors of tyrosine phosphatases, elevating ROS alone mimicked TCR and other phosphotyrosine signals. ROS also dramatically reprograms cellular metabolism: by inhibiting aconitase, citrate is driven from the mitochondria where it is converted to acetyl-CoA, acting as a substrate for de novo lipogenesis. As a result, while exhausted cells possess dysfunctional mitochondria and compete poorly for glucose, they are loaded with lipid droplets and repress fatty acid oxidiation and lipolysis. While we know that mitochondrial stress can drive T cells to exhaustion and that terminally exhausted T cells are metabolically insufficient, the mechanisms that ultimately drive and enforce the phenotype remain unclear. In this Proposal, we will identify the metabolic underpinnings of T cell exhaustion: how metabolic stress can interfere with signaling, transcription, and differentiation. AIM 1: Determine how oxidative stress alters T cell signaling cascades at the level of phosphatase inhibition. ROS play central roles in signaling as inhibitors of tyrosine phosphatases. We will determine the role of ROS in exhausted T cell function in vivo, and use proteomics and transcriptomic technologies to identify the phosphorylation cascades susceptible to ROS induction. AIM 2: Identify how ROS-mediated changes in metabolic flux undermine T cell function. In this Aim, we will explore the role increased lipid storage plays in T cell function and ask whether these elevated levels of lipids represent `dead weight' or an untapped fuel source. AIM 3: Define the importance of altered nutrient pathways induced through oxidative stress responses. Our data suggest Slc16a11 similarly supports lactate uptake into exhausted T cells and maintains their dysfunctional state. Using a conditional knockout mouse and blocking antibodies, we will determine the importance of monocarboxylate metabolism in exhausted T cell biology.

项目摘要/摘要 免疫疗法的成功，例如封闭抑制性“检查点”分子的封锁已经改变了 癌症的治疗范例。但是，强大的反应仅限于患者的一部分 强调需要进一步了解疲惫的T细胞的生物学：什么是驱动其分化的原因， 保持它们的功能障碍，以及如何重新启动以根除肿瘤细胞。我们的实验室和其他人 已经揭示了代谢胁迫和线粒体功能障碍是T细胞耗尽的关键驱动因素 从细胞外部和细胞固有的角度来看。我们最近报道了线粒体应力和反应性 氧气（ROS）生产，面对低氧环境下的无法忍受的水平 持续的抗原足以使细胞偏离终极耗尽的命运。抗氧化剂两者 药理学和遗传可能会使T细胞从精疲力尽到更具功能性命运的分化。但是，正是ROS产生如何改变T细胞命运和功能尚不清楚。更有趣的人之一 观察结果是通过线粒体功能障碍改变T细胞信号传导的ROS：因为过氧化物是一种 对酪氨酸磷酸酶的较强抑制剂，单独抬高ROS模仿TCR和其他 磷酸酪氨酸信号。 ROS还显着重新编程了细胞代谢：通过抑制刺激酶，柠檬酸盐是从线粒体驱动的，将其转换为乙酰-COA，用作NOKO的底物 脂肪生成。结果，耗尽的细胞具有功能失调的线粒体，并且竞争很差 葡萄糖，它们装有脂质液滴，并抑制脂肪酸氧化和脂解。虽然我们知道 线粒体应力会使T细胞疲惫，终端耗尽的T细胞代谢 不足，最终驱动和执行表型的机制尚不清楚。在此提案中， 我们将确定T细胞衰竭的代谢基础：代谢应力如何干扰 信号，转录和分化。目标1：确定氧化应激如何改变T细胞信号传导 在磷酸酶抑制水平上的级联反应。 ROS作为酪氨酸的抑制剂在信号传导中起着核心作用 磷酸酶。我们将确定ROS在体内耗尽的T细胞功能中的作用，并使用蛋白质组学和 转录组技术以鉴定磷酸化级联反应被ROS诱导。目标2： 确定ROS介导的代谢通量的变化如何破坏T细胞功能。在此目标中，我们将探索 该作用增加了脂质存储在T细胞功能中的作用，并询问这些脂质水平是否升高 表示“死重”或未开发的燃料源。目标3：定义通过氧化应激反应引起的养分途径改变的重要性。我们的数据表明，SLC16A11类似地支持乳酸摄取到耗尽的T细胞中，并保持其功能失调的状态。使用条件敲除小鼠和阻断抗体，我们将确定单羧酸盐代谢在耗尽的T细胞生物学中的重要性。