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

 描述（由申请人提供）：炎症性疾病通常由效应CD 4 T细胞（Teff）的不适当反应引起。Th 1和Th 17 Teff被认为驱动各种免疫病理学，包括炎症性肠病（IBD）和多发性硬化症（MS）。相反，调节性T细胞（Treg）抑制Teff以保护免受疾病。因此，努力将免疫平衡向耐受性转变的关键治疗目标是选择性抑制Teff并促进Treg。我们在这里表明，Teff和Treg利用 从根本上不同的代谢程序，并提出确定每个子集的具体要求将提供一种新的方法来选择性地调节炎症性疾病中的CD 4 T细胞。我们发现Th 1和Th 17细胞具有葡萄糖转运蛋白Glut 1的高表达，特别是Th 17细胞具有增加的丙酮酸脱氢酶激酶1（PDHK 1），糖酵解中间体富集至3-磷酸甘油醛脱氢酶（GAPDH），以及糖酵解通量至乳酸的速率升高。相比之下，Treg的Glut 1和PDHK 1表达较低，糖酵解通量有限，而是富含线粒体氧化基因表达和代谢物。重要的是，我们对T细胞特异性Glut 1条件性缺失或靶向PDHK 1的分析表明，Teff在体内的功能选择性地需要糖酵解程序。在这里，我们建议测试通过高分辨率代谢组学质谱法鉴定为在Teff中选择性调节并且可能为Th 1和Th 17提供漏洞的其他代谢事件。相比之下，Treg代谢的调节和要求知之甚少。然而，我们的数据显示转录因子FoxP 3促进Treg氧化代谢并抑制磷酸肌醇-3-激酶（PI 3 K）/Akt/mTOR通路以降低Glut 1表达和糖酵解。令人惊讶的是，高糖酵解率降低了Treg的抑制能力，因为我们发现Glut 1转基因Treg功能受损，不能完全保护IBD。基于Teff和Treg的不同代谢需求，我们假设关键的葡萄糖依赖性代谢物对Teff是选择性必需的，而糖酵解是FoxP 3抑制以优化抑制能力的Treg弱点。为了测试该模型，我们将：（1）鉴定和表征Teff特化和功能选择性所需的代谢物和代谢途径;（2）确定FoxP 3如何调节代谢以及糖酵解在Treg扩增和保护免受IBD中的作用;（3）确定糖酵解的抑制如何改变Teff和Treg平衡，其中Teff和Treg平衡是由Teff特异性和功能性决定的。 使用选择性PDHK 1抑制剂和靶向Teff代谢脆弱性的MS模型。这些研究将建立Teff和Treg生理学的特异性和选择性代谢需求，并确定调节炎性疾病中Teff和Treg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.