Exploiting metabolic vulnerabilities of CD4 T cell subsets to control inflammatory disease

利用 CD4 T 细胞亚群的代谢脆弱性来控制炎症性疾病

• 批准号: 10586461
• 负责人: Jeffrey C. Rathmell
• 金额: $ 40.73万
• 依托单位: VANDERBILT UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10586461
• 关键词: Amino Acids; Apoptosis; Autoimmune Diseases; Biological Assay; CD4 Positive T Lymphocytes; CRISPR screen; Carbon; Cell physiology; Cells; Cellular Metabolic Process; Cellular biology; DNA Methylation; Data; Dependence; Diet; Disease; Disease model; Enzymes; Equilibrium; Eragrostis; FOXP3 gene; Fever; Folic Acid; Folic Acid Antagonists; Folic Acid Deficiency; Formates; Formyltetrahydrofolates; Genetic; Glucose; Goals; Guide RNA; Human; IL17 gene; Image; Immune; Immunity; Immunologics; Impairment; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Interferon Type II; Interruption; Libraries; Measures; Metabolic; Metabolic Pathway; Metabolism; Methionine; Methods; Methotrexate; Mitochondria; Mus; Nucleotides; Nutrient; Nutrient availability; Oxidoreductase; Pathway interactions; Pattern; Pharmaceutical Preparations; Play; Positron-Emission Tomography; Production; Purines; Reactive Oxygen Species; Regulation; Regulatory Pathway; Regulatory T-Lymphocyte; Role; Shapes; Signal Transduction; Site; T cell differentiation; T cell regulation; T-Cell Activation; T-Cell Proliferation; T-Lymphocyte; T-Lymphocyte Subsets; Temperature; Testing; Th1 Cells; Therapeutic; Tissues; Tracer; Work; conditional knockout; cytokine; deprivation; dietary; effector T cell; glucose uptake; histone methylation; in vivo; metabolomics; microbiota; nucleotide metabolism; programs; recruit; response; uptake

SUMMARY Inflammatory diseases are often driven by inappropriate responses of effector CD4 T cells (Teff). IL17, IFNγ, or dual-producing polyfunctional effector Th1, Th17, or Th17.1 T cells can become imbalanced with suppressive Treg CD4 T cells in a variety of disease settings, including inflammatory bowel diseases (IBD). A key therapeutic objective in efforts to shift the immunologic balance towards tolerance, therefore, is to selectively inhibit Teff and promote Treg. We have shown that Teff and Treg subsets utilize different metabolic programs that represent fundamental features of T cell biology. Here we explore one carbon (1C) metabolism and related microenvironmental factors to modulate CD4 T cells in inflammatory diseases. 1C metabolism integrates multiple nutrient inputs to provide intermediates for de novo methionine and purine synthesis and is commonly targeted with anti-folate drugs. An in vivo CRISPR screen of primary T cells in IBD with a 1C metabolism enzyme-focused gRNA library identified the mitochondrial enzyme Methylene-tetrahydrofolate Dehydrogenase 2 (MTHFD2) as conditionally essential for effector T cell proliferation and inflammation. MTHFD2 was upregulated in T cells a variety of inflammatory conditions and while MTHFD2-deficiency impaired Teff, MTHFD-deficient Treg had increased FoxP3 expression in both mouse and human T cells. Consistent with a role as a metabolic checkpoint on inflammation, MTHFD2-deficiency protected against IBD and other inflammatory diseases. Mechanistically, MTHFD2 inhibition suppressed mTORC1 activity, possibly through reduced methionine and/or interrupted purine synthesis. Importantly, local nutrients play key roles in 1C metabolism and T cell fate. To quantify T cell access to nutrients in vivo, we established Positron Emission Tomography (PET) tracer-based methods to directly image and measure nutrient uptake in vivo. These studies showed a sharp increase in T cell glucose uptake in inflammation. In addition, IBD is often associated with folate-deficiency. The effects of dietary folate on T cell 1C metabolism, mTORC1 signaling, and fate, however, are unclear. Because inflammation is associated with fevers and enzymes are temperature-dependent, we also tested fever conditions on T cell metabolism. We found fever led to increased cytokine production from Teff and mitochondrial Reactive Oxygen Species (ROS) specifically in Th1 cells that, surprisingly, led to Tp53-dependent apoptosis. These findings support the hypothesis that 1C metabolism is limiting and serves as a metabolic checkpoint to integrate local nutrients and physical conditions through MTHFD2 and mTORC1 signaling to provide new immunometabolic targets to modulate effector and regulatory T cells. To test this, we will: (1) Test the role and mechanism of MTHFD2 as a limiting enzyme in methionine and nucleotide synthesis essential for mTORC1 signaling and effector T cells; and (2) Determine how nutrient and microenvironmental factors such as folate and fever influence effector and regulatory T cell metabolism and inflammation. These studies will test MTHFD2 and identify new immunometabolic mechanisms and targets that contribute to or may be exploited to treat inflammatory disease.

概括 炎症性疾病通常是由效应 CD4 T 细胞 (Teff) 的不当反应引起的。 双产生多功能效应 Th1、Th17 或 Th17.1 T 细胞可能因抑制而变得不平衡 Treg CD4 T 细胞在多种疾病中发挥作用，包括炎症性肠病 (IBD) 的关键治疗方法。 因此，努力将免疫平衡转向耐受性的目标是选择性抑制 Teff 和 促进 Treg 我们已经证明 Teff 和 Treg 子集利用代表不同的代谢程序。 T 细胞生物学的基本特征在此我们探讨一碳 (1C) 代谢及相关的。 调节炎症性疾病中 CD4 T 细胞 1C 代谢的微环境因素整合了多种因素。 营养投入，为从头合成蛋氨酸和嘌呤提供中间体，并且通常是目标 使用抗叶酸药物对 IBD 中的原代 T 细胞进行体内 CRISPR 筛选，并以 1C 代谢酶为重点。 gRNA 文库将线粒体酶亚甲基四氢叶酸脱氢酶 2 (MTHFD2) 鉴定为 MTHFD2 在 T 细胞中上调，对于效应 T 细胞增殖和炎症是必需的。 多种炎症状况，虽然 MTHFD2 缺陷会损害 Teff，但 MTHFD 缺陷的 Treg 会受损 小鼠和人类 T 细胞中 FoxP3 表达增加，与代谢检查点的作用一致。 从机制上讲，MTHFD2 缺陷可以预防 IBD 和其他炎症性疾病。 MTHFD2 抑制可能通过减少蛋氨酸和/或中断嘌呤来抑制 mTORC1 活性 重要的是，局部营养物质在 1C 代谢和 T 细胞命运中发挥着关键作用。 针对体内营养物质，我们建立了基于正电子发射断层扫描（PET）示踪剂的方法来直接成像 并测量体内营养吸收。这些研究表明，T 细胞葡萄糖吸收急剧增加。 此外，炎症性肠病通常与叶酸缺乏有关。膳食叶酸对 T 细胞的影响。 然而，1C 代谢、mTORC1 信号传导和命运尚不清楚，因为炎症与此相关。 发烧和酶都依赖于温度，我们还测试了发烧条件对 T 细胞代谢的影响。 发烧导致苔麸和线粒体活性氧 (ROS) 产生的细胞因子增加 特别是在 Th1 细胞中，令人惊讶的是，它导致了 Tp53 依赖性细胞凋亡。这些发现支持了这一观点。 假设 1C 代谢受到限制，并作为代谢检查点来整合局部营养物质和 通过 MTHFD2 和 mTORC1 信号传递来提供新的免疫代谢目标 调节效应和调节性 T 细胞 为了测试这一点，我们将： (1) 测试 MTHFD2 作为调节剂的作用和机制。 限制 mTORC1 信号传导和效应 T 细胞必需的蛋氨酸和核苷酸合成酶； (2) 确定营养和微环境因素（例如叶酸和发烧）如何影响效应器和 这些研究将测试 MTHFD2 并鉴定新的调节性 T 细胞代谢和炎症。 有助于或可用于治疗炎症性疾病的免疫代谢机制和靶点。