Metabolic reprogramming to improve EGFRvIII CAR T cell persistence

摘要 使用嵌合抗原受体（CAR）T细胞的连续免疫疗法已成功地对抗一些液体 肿瘤，但未能治愈实体瘤。CAR T细胞对实体瘤失败的关键原因是抗原 异质性然而，CAR T细胞在动物模型中针对实体瘤的临床前研究显示了一些优势。 在胶质母细胞瘤的脑肿瘤小鼠模型中，CAR T细胞识别EGFRvIII肿瘤特异性 抗原成功地消除了肿瘤，但仅针对同质肿瘤，并且仅当小鼠首先 在CAR T细胞输注之前接受淋巴细胞消耗宿主调节（通过全身照射）。虽然 淋巴细胞消耗宿主调节为CAR T细胞扩增提供了免疫学空间，但这在CAR T细胞扩增中是有问题的。 异质性实体瘤的背景，因为它损害内源性宿主免疫，这对于靶向至关重要 在实体瘤中发现的替代抗原。因此，成功的CAR T细胞治疗固体 异质性肿瘤将需要创新的方法来改善CAR T细胞的持久性， 用于宿主淋巴细胞消耗调节，并允许宿主内源性免疫的保存。为了实现这一点， 我们建议利用EGFRvIIICART细胞的代谢重编程。过去十年的许多研究 现在已经清楚地证明了T细胞分化，功能和代谢之间的联系。一个主要 氧化代谢支持T细胞监视、存活和记忆，而糖酵解代谢占主导地位。 代谢支持生物合成以促进效应T细胞增殖和功能，但与 寿命缩短。该R21提案的目标是（1）利用EGFRvIII的代谢重编程 CAR T细胞以改善CAR T细胞在体外和体内的持久性，和（2）测试修饰的EGFRvIII的能力， CAR T细胞在不存在淋巴细胞消耗宿主调节的情况下递送以保留内源性免疫调节。 系统和改进的异质性肿瘤杀伤。我们假设增加氧化的方法 代谢将改善CAR T细胞的持久性，消除对淋巴细胞消耗宿主调节的需要， 维持宿主内源性免疫，并最终改善异质性肿瘤杀伤。来测试我们 假设，我们将执行以下具体目标：1）确定遗传和药理学策略， 修饰EGFRvIII CAR T细胞以增强代谢适应性以支持持久性;和2）测试是否代谢适应性 在不存在淋巴细胞消耗宿主调节的情况下递送的合适的鼠EGFRvIII CAR T细胞保留了 内源性免疫如果成功，这些方法可以在未来的研究中与战略合作， 增强针对异质性肿瘤的内源性宿主免疫，并克服敌对性免疫抑制， 肿瘤环境这项工作虽然在脑肿瘤模型中进行，但与CAR T细胞治疗相关 对抗多种实体瘤

ABSTRACT Adoptive immunotherapy using chimeric antigen receptor (CAR) T cells has been successful against some liquid tumors, but has failed to cure solid tumors. A key reason for CAR T cell failure against solid tumors is antigen heterogeneity. However, pre-clinical studies of CAR T cells against solid tumors in animal models show some promise; in a brain tumor mouse model of glioblastoma, CAR T cells recognizing the EGFRvIII tumor-specific antigen are successful in eliminating tumor, but only against homogeneous tumor and only when mice first receive lymphodepletive host conditioning (via total body irradiation) prior to CAR T cell infusion. Although lymphodepletive host conditioning provides immunological space for CAR T cell expansion, it is problematic in the context of heterogeneous solid tumors, as it impairs endogenous host immunity which is critical for targeting alternative antigens found within the solid tumor. For that reason, successful CAR T cell treatment against solid heterogeneous tumors will require innovative methods to improve CAR T cell persistence to eliminate the need for host lymphodepletive conditioning, and allow for preservation of host endogenous immunity. To achieve this, we propose to utilize metabolic reprogramming of EGFRvIII CAR T cells. Many studies over the last decade have now clearly demonstrated a link between T cell differentiation, function, and metabolism. A predominantly oxidative metabolism supports T cell surveillance, survival, and memory, whereas a predominantly glycolytic metabolism supports biosynthesis to promote effector T cell proliferation and function, but is associated with decreased longevity. The objectives of this R21 proposal are to (1) utilize metabolic reprogramming of EGFRvIII CAR T cells to improve CAR T cell persistence in vitro and in vivo, and (2) test the ability of modified EGFRvIII CAR T cells delivered in the absence of lymphodepletive host conditioning to preserve the endogenous immune system and improve heterogeneous tumor killing. We hypothesize that methods that increase oxidative metabolism will improve CAR T cell persistence, eliminating the need for lymphodepletive host conditioning, maintaining host endogenous immunity, and ultimately improving heterogeneous tumor killing. To test our hypothesis, we will perform the following specific aims: 1) Identify genetic and pharmacological strategies to modify EGFRvIII CAR T cells for enhanced metabolic fitness to support persistence; and 2) Test if metabolically fit murine EGFRvIII CAR T cells delivered in the absence of lymphodepletive host conditioning preserve endogenous immunity. If successful, these approaches can be partnered in future studies with strategies to enhance endogenous host immunity against heterogeneous tumors and overcome a hostile immunosuppressive tumor environment. This work, while performed in a brain tumor model, would be relevant for CAR T cell therapy against multiple solid tumors.