Uncovering the metabolic underpinnings of T cell exhaustion

揭示 T 细胞耗竭的代谢基础

• 批准号: 10593593
• 负责人: Greg M. Delgoffe
• 金额: $ 63.36万
• 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/10593593
• 关键词: Acetyl Coenzyme A; Aconitate Hydratase; Antigens; Antioxidants; Biology; Blocking Antibodies; Cell physiology; Cells; Cellular biology; Characteristics; Chronic; Citrates; Citric Acid Cycle; Cysteine; 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; Pharmacology; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotyrosine; Play; Production; Protein Tyrosine Phosphatase; Proteome; Proteomics; Reactive Oxygen Species; Regulatory T-Lymphocyte; Reporting; Role; Signal Transduction; Source; Stress; T cell differentiation; T-Lymphocyte; Technology; Tissues; Tumor Immunity; Tumor-infiltrating immune cells; Tyrosine; Up-Regulation; Weight; anti-cancer; anti-tumor immune response; biological adaptation to stress; conditional knockout; cytokine; cytotoxic; cytotoxicity; design; exhaust; exhaustion; fatty acid oxidation; improved; in vivo; inhibitor; lipid biosynthesis; member; mitochondrial dysfunction; neoplastic cell; novel; novel therapeutics; overexpression; patient subsets; prevent; progenitor; programmed cell death protein 1; response; self-renewal; stress reactivity; success; transcriptomics; 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.

项目总结/摘要 免疫疗法的成功，如阻断共抑制“检查点”分子，改变了免疫系统的功能。 癌症的治疗模式。然而，事实上，强有力的反应仅限于一部分患者， 强调需要进一步了解耗尽的T细胞的生物学：是什么驱动它们的分化， 维持它们的功能障碍，以及它们如何被重新激活以根除肿瘤细胞。我们的实验室和其他 已经揭示了代谢应激和线粒体功能障碍是T细胞耗竭的关键驱动因素， 从细胞外在和细胞内在的角度。我们最近报道，线粒体应激和反应性 氧物种（ROS）的产生，在缺氧环境下，在面对 持久性抗原足以使细胞偏离最终耗尽的命运。抗氧化剂 药理学和遗传学可以使T细胞分化偏离衰竭，转向功能更强的命运。但ROS的产生如何改变T细胞的命运和功能仍不清楚。其中一个更有趣的 观察结果是通过线粒体功能障碍改变T细胞信号传导来升高ROS：因为过氧化物是 酪氨酸磷酸酶的更有效的抑制剂，提高ROS单独模仿TCR和其他 磷酸酪氨酸信号。ROS还显著地重新编程细胞代谢：通过抑制乌头酸酶，柠檬酸盐从线粒体中被驱动，在线粒体中它被转化为乙酰辅酶A，作为从头合成的底物。 脂肪生成因此，虽然疲惫的细胞具有功能失调的线粒体， 葡萄糖，它们装载有脂滴并抑制脂肪酸氧化和脂解。虽然我们知道 线粒体应激可以驱使T细胞耗尽，并且终末耗尽的T细胞在代谢上被破坏。 尽管这些研究尚不充分，但最终驱动和实施表型的机制仍不清楚。在本建议书中， 我们将确定T细胞耗竭的代谢基础：代谢应激如何干扰T细胞耗竭， 信号传导、转录和分化。目的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级联。活性氧作为酪氨酸抑制剂在信号转导中发挥重要作用 磷酸酶我们将确定活性氧在体内耗尽的T细胞功能中的作用，并使用蛋白质组学和 转录组学技术来鉴定对ROS诱导敏感的磷酸化级联。目标2： 确定ROS介导的代谢通量变化如何破坏T细胞功能。在本目标中，我们将探讨 增加的脂质储存在T细胞功能中的作用，并询问这些升高的脂质水平是否 代表“自重”或未开发的燃料来源。目的3：确定通过氧化应激反应诱导的营养途径改变的重要性。我们的数据表明Slc 16 a11类似地支持乳酸摄取到耗尽的T细胞中并维持其功能障碍状态。使用条件性敲除小鼠和阻断抗体，我们将确定一元羧酸代谢在耗尽的T细胞生物学中的重要性。