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

 描述(由申请人提供)：炎症性疾病通常是由效应器CD4T细胞(TEFF)的不适当反应引起的。Th1和Th17Tef被认为是多种免疫病理的驱动力，包括炎症性肠病(IBD)和多发性硬化症(MS)。相比之下，调节性T细胞(Treg)抑制TEFF以防止疾病。因此，努力将免疫平衡转向耐受的一个关键治疗目标是选择性地抑制TJeff并促进Treg。我们在这里展示了特夫和特雷格利用 并提出，确定每个亚群的特定需求将提供一种新的方法，选择性地调节炎症性疾病中的CD4T细胞。我们发现Th1和Th17细胞高表达葡萄糖转运蛋白Glut1，特别是Th17细胞增加了丙酮酸脱氢酶1(PDHK1)，糖酵解中间产物浓缩到甘油醛3-磷酸脱氢酶(GAPDH)，糖酵解通量到乳酸的比率增加。相比之下，Treg则低表达Glut1和PDHK1，限制糖酵解通量，反而富含线粒体氧化基因表达和代谢产物。重要的是，我们对T细胞特异性Glut1条件性缺失或靶向PDHK1的分析表明，糖酵解程序在体内发挥作用是选择性的。在这里，我们建议测试额外的代谢事件，这些代谢事件由高分辨率代谢组质谱鉴定，在TEF中有选择性地调节，可能提供Th1和Th17的易感性。相比之下，Treg代谢的调节和要求一直知之甚少。然而，我们的数据表明，转录因子FoxP3促进Treg氧化代谢，并抑制磷脂酰肌醇-3-激酶(PI3K)/Akt/mTOR途径，从而降低Glut1的表达和糖酵解。令人惊讶的是，高糖酵解率降低了Treg抑制能力，因为我们发现Glut1转基因Treg功能受损，不能完全预防IBD。根据TJeff和Treg的不同代谢需求，我们假设关键的葡萄糖依赖代谢物对TJeff是选择性必需的，而糖酵解是一种Treg漏洞，FoxP3抑制它以优化抑制能力。为了验证这一模型，我们将：(1)鉴定和表征TJeff的特性和功能所需的代谢物和代谢途径；(2)确定FoxP3如何调节新陈代谢，以及糖酵解在Treg扩张和预防IBD中的作用；(3)确定抑制糖酵解如何改变TJeff和Treg的平衡。 使用选择性PDHK1抑制剂的多发性硬化症模型和靶向TJeff代谢易损性。这些研究将确定特雷夫和特雷格生理的特定和选择性代谢需求，并确定在炎症性疾病中调节特雷夫和特雷格平衡的途径。

 DESCRIPTION (provided by applicant): Inflammatory diseases are often caused by inappropriate responses of effector CD4 T cells (Teff). Th1 and Th17 Teff are recognized to drive a variety of immune pathologies, including Inflammatory Bowel Disease (IBD) and Multiple Sclerosis (MS). Regulatory T cells (Treg), in contrast, suppress Teff to protect from disease. A key therapeutic objective in efforts to shift the immunologic balance towards tolerance, therefore, is to selectively inhibit Teff and promote Treg. We show here that Teff and Treg utilize fundamentally different metabolic programs and propose that identifying specific requirements of each subset will provide a new approach to selectively modulate CD4 T cells in inflammatory disease. We have found Th1 and Th17 cells have high expression of the glucose transporter Glut1, and Th17 cells in particular have increased Pyruvate Dehydrogenase Kinase 1 (PDHK1), an enrichment of glycolytic intermediates up to Glyceraldehyde 3-Phosphate Dehydrogenase (GAPDH), and elevated rates of glycolytic flux to lactate. Treg, in contrast, have low expression of Glut1 and PDHK1, limited glycolytic flux, and are instead enriched for mitochondrial oxidative gene expression and metabolites. Importantly, our analysis of T cell specific Glut1 conditional deletion or targeting of PDHK1 showed that a glycolytic program is selectively required for Teff function in vivo. Here we propose to test additional metabolic events that were identified by high- resolution metabolomics mass spectrometry as selectively regulated in Teff and that may provide vulnerabilities for Th1 and Th17. The regulation and requirements of Treg metabolism, in contrast, have been poorly understood. However, our data show that the transcription factor FoxP3 promotes Treg oxidative metabolism and suppresses the Phosphoinositide-3-kinase (PI3K)/Akt/mTOR pathway to lower Glut1 expression and glycolysis. Surprisingly, high rates of glycolysis reduced Treg suppressive capacity, as we found Glut1 transgenic Treg are functionally impaired and could not fully protect from IBD. Based on the distinct metabolic requirements of Teff and Treg, we hypothesize that key glucose-dependent metabolites are selectively essential for Teff while glycolysis is a Treg vulnerability that FoxP3 restrains to optimize suppressive capacity. To test this model we will: (1) Identify and characterize metabolites and metabolic pathways selectively required for Teff specification and function; (2) Determine how FoxP3 regulates metabolism and the role of glycolysis in Treg expansion and protection from IBD; (3) Establish how inhibition of glycolysis alters the Teff and Treg balance in a model of MS using selective PDHK1 inhibitors and targeting of Teff metabolic vulnerabilities. These studies will establish specific and selective metabolic demands of Teff and Treg physiology and identify pathways to modulate the Teff and Treg balance in inflammatory diseases.