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.

项目概要/摘要 免疫疗法的成功，例如封锁共抑制“检查点”分子，已经改变了 癌症的治疗范式。然而，事实上，强烈的反应仅限于一小部分患者 强调需要进一步了解耗竭 T 细胞的生物学：是什么驱动了它们的分化， 维持它们的功能障碍，以及如何重新激活它们以根除肿瘤细胞。我们的实验室和其他 研究表明，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来看。我们最近报道线粒体应激和反应性 氧气（ROS）的产生，在缺氧环境下达到了无法忍受的水平 持久性抗原足以使细胞陷入最终疲惫的命运。抗氧化剂两者 药理学和遗传因素可能会使 T 细胞分化从疲惫状态转向更具功能性的命运。但 ROS 的产生究竟如何改变 T 细胞的命运和功能仍不清楚。其中比较有趣的一个 观察结果显示，线粒体功能障碍改变了 T 细胞信号传导，从而提高了 ROS：因为过氧化物是其中之一 更有效的酪氨酸磷酸酶抑制剂，单独提高 ROS 模拟 TCR 和其他 磷酸酪氨酸信号。 ROS 还可以显着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转化为乙酰辅酶A，作为从头的底物 脂肪生成。因此，虽然精疲力竭的细胞拥有功能失调的线粒体，并且在竞争中表现不佳 葡萄糖，它们载有脂滴并抑制脂肪酸氧化和脂肪分解。虽然我们知道 线粒体应激可促使 T 细胞耗尽，而最终耗尽的 T 细胞会发生代谢反应 但最终驱动和强化表型的机制仍不清楚。在本提案中， 我们将确定 T 细胞耗竭的代谢基础：代谢压力如何干扰 信号传导、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 磷酸酶抑制水平的级联反应。 ROS 作为酪氨酸抑制剂在信号传导中发挥核心作用 磷酸酶。我们将确定 ROS 在体内耗竭 T 细胞功能中的作用，并利用蛋白质组学和 转录组技术可识别易受 ROS 诱导影响的磷酸化级联。目标2： 确定 ROS 介导的代谢通量变化如何破坏 T 细胞功能。为了这个目标，我们将探索 脂质储存增加在 T 细胞功能中所起的作用，并询问脂质水平是否升高 代表“自重”或未开发的燃料来源。目标 3：定义氧化应激反应引起的营养途径改变的重要性。我们的数据表明，Slc16a11 同样支持疲惫的 T 细胞摄取乳酸并维持其功能障碍状态。使用条件敲除小鼠和封闭抗体，我们将确定单羧酸代谢在疲惫的 T 细胞生物学中的重要性。