Glycolysis and Glutaminase in CD8 T cell differentiation and anti-tumor immunity

总结 免疫疗法改变了癌症治疗并改善了临床结果，但它并不能治愈大多数癌症 患者。抗 PD1 单克隆抗体和嵌合抗原受体 (CAR) T 细胞等治疗 通过增强癌症特异性干扰素 γ 产生 Th1 CD4 T 细胞的活性来发挥作用 细胞毒性 CD8 T 细胞 (CTL)。然而，效应器功能的增加必须与抗效应能力相平衡。 癌症T细胞能够长期存在。免疫疗法的一个关键目标是增强效应功能，同时 维持 T 细胞的寿命和记忆力。 Rathmell 实验室的工作现在清楚地表明，效应 T 细胞 利用高速率的糖酵解，而记忆细胞则利用线粒体途径。这里我建议测试cell 代谢作为增强免疫治疗中效应 T 细胞和记忆 T 细胞群的一种手段。 T细胞 激活后从根本上改变其代谢并增加糖酵解和谷氨酰胺氧化 （谷氨酰胺分解）支持分化、效应器功能和长期记忆的最终生成 依赖于线粒体。 T 细胞谷氨酰胺代谢的调节可能会增强 通过增强 T 细胞效应功能或记忆能力的免疫疗法。 Rathmell 实验室已经证明 代谢程序有氧糖酵解对于炎症和炎症中效应 T 细胞 (Teff) 的功能至关重要 在肿瘤中。谷氨酰胺分解通过将谷氨酰胺转化为三羧酸来补充糖酵解，为 T 细胞提供燃料 酸循环中间体α-酮戊二酸（aKG）。使用谷氨酰胺分解酶的条件敲除 谷氨酰胺酶（GLS），可将谷氨酰胺转化为谷氨酸，以及目前处于临床阶段的 GLS 抑制剂 作为抗癌剂的试验中，我们发现抑制 GLS 会导致代偿性增加 糖酵解增强 Th1 和 CTL Teff 功能和分化。除了增加效应器 然而，我发现 GLS 抑制也会增加抑制性受体的表达，并且慢性 GLS 缺陷最终会抑制 T 细胞。相反，短暂的 GLS 抑制增强了 Teff 功能，同时 还启动线粒体代谢以实现类似记忆的分化，并提高 T 细胞的持久性 体内。在这个提案中，我将测试短暂的 GLS 抑制可以增强 Teff 功能的假设，并且 维持 T 细胞存活和记忆以提高抗癌免疫治疗效果，而慢性 GLS 抑制将驱动代偿性糖酵解、终末 Teff 分化和衰竭。我将：（1）测试如何 短暂与慢性 GLS 抑制通过确定记忆 T 细胞形成的差异来影响 CTL 命运， 评估代偿性糖酵解对 Teff 表型的贡献，并建立线粒体 GLS 抑制的后果； (2)测试GLS抑制对免疫治疗效果的影响 CD19 靶向 CAR T 细胞和抗 PD1 治疗。这些研究将展示一种新方法 改进抗癌免疫治疗并强调利用 GLS 抑制调节 T 细胞的策略 代谢和分化。

Summary Immunotherapy has transformed cancer treatment and improved clinical outcomes, but it does not cure most patients. Treatments such as anti-PD1 monoclonal antibodies and chimeric antigen receptor (CAR) T cells function by boosting the activity of cancer-specific interferon gamma-producing Th1 CD4 T cells and cytotoxic CD8 T cells (CTL). Increased effector function, however, must be balanced with the ability of anti- cancer T cells to persist long-term. A key goal of immunotherapy is to enhance effector function while maintaining T cell longevity and memory. It is now clear from work in the Rathmell lab that effector T cells utilize high rates of glycolysis while memory cells utilize mitochondrial pathways. Here I propose to test cell metabolism as a means to enhance both effector and memory T cell populations in immunotherapy. T cells radically alter their metabolism upon activation and increase glycolysis and glutamine oxidation (glutaminolysis) to support differentiation, effector function, and eventual generation of long-term memory that depend on mitochondria. Modulation of T cell glutamine metabolism may augment the efficacy of immunotherapy by enhancing both T cell effector function or memory capacity. The Rathmell Lab has shown that the metabolic program aerobic glycolysis is essential for effector T cell (Teff) function in inflammation and in tumors. Glutaminolysis complements glycolysis to fuel T cells by converting glutamine to the tricarboxylic acid cycle intermediate alpha-ketoglutarate (aKG). Using a conditional knockout of the glutaminolysis enzyme Glutaminase (GLS), which converts glutamine to glutamate, and an inhibitor of GLS that is currently in clinical trials as an anti-cancer agent, we have found that inhibition of GLS leads to a compensatory increase in glycolysis that enhances Th1 and CTL Teff function and differentiation. In addition to increasing effector function, however, I found that GLS inhibition also increases expression of inhibitory receptors, and chronic GLS deficiency ultimately suppresses T cells. In contrast, transient GLS inhibition enhanced Teff function while also priming mitochondrial metabolism for a memory-like differentiation, and led to improved T cell persistence in vivo. In this proposal, I will test the hypothesis that transient GLS inhibition can augment Teff function and maintain T cell survival and memory to boost anti-cancer immunotherapy efficacy, whereas chronic GLS inhibition will drive compensatory glycolysis, terminal Teff differentiation, and exhaustion. I will: (1) Test how transient versus chronic GLS inhibition affects CTL fate by determining differences in memory T cell formation, assessing the contribution of compensatory glycolysis to Teff phenotypes, and establishing the mitochondrial consequences of GLS inhibition; and (2) Test the effect of GLS inhibition on the immunotherapy efficacy of CD19-targeted CAR T cells and anti-PD1 treatment. These studies will demonstrate a new approach to improve anti-cancer immunotherapy and highlight a strategy of using GLS inhibition to modulate T cell metabolism and differentiation.