Metabolic reprogramming to improve EGFRvIII CAR T cell persistence

摘要 使用嵌合抗原受体(CAR)T细胞的过继免疫疗法已经成功地针对一些液体 肿瘤，但未能治愈实体肿瘤。CAR T细胞抗实体瘤失败的关键原因是抗原 异质性。然而，CAR T细胞在动物模型中对抗实体瘤的临床前研究显示，一些 在脑胶质母细胞瘤小鼠模型中，CAR T细胞识别肿瘤特异性EGFRvIII 抗原在清除肿瘤方面是成功的，但只针对同种肿瘤，而且只有当小鼠首先 在CAR T细胞输注前接受淋巴消耗宿主调理(通过全身照射)。虽然 淋巴消耗性宿主条件作用为CAR T细胞的扩增提供了免疫空间，但它在 异质性实体肿瘤的背景，因为它损害内源性宿主免疫，而内源性宿主免疫是靶向的关键 在实体瘤中发现的替代抗原。出于这个原因，成功的CAR T细胞治疗针对Solid 异质肿瘤将需要创新的方法来提高CAR T细胞的持久性，以消除需要 用于宿主淋巴耗竭的调节，并允许保存宿主的内源性免疫。为了实现这一目标， 我们建议利用EGFRvIII CAR T细胞的代谢重新编程。过去十年来的许多研究 现在已经清楚地证明了T细胞分化、功能和新陈代谢之间的联系。一个主要的 氧化代谢支持T细胞的监视、存活和记忆，而以糖酵解为主的 代谢支持生物合成以促进效应器T细胞的增殖和功能，但与 寿命下降。该R21提案的目标是(1)利用EGFRvIII的代谢重新编程 CAR T细胞提高CAR T细胞在体内外的持久性；(2)检测修饰的EGFRvIII的能力 CAR T细胞在没有淋巴去除的宿主条件下传递以保护内源性免疫 系统，提高异质肿瘤杀伤力。我们假设增加氧化能力的方法 新陈代谢将提高CAR T细胞的持久性，消除对淋巴消耗宿主条件的需要， 维持宿主内源性免疫，最终提高异种肿瘤杀伤力。测试我们的 假设，我们将执行以下具体目标：1)确定遗传和药物策略以 修改EGFRvIII CAR T细胞以增强代谢适应性，以支持持久性；以及2)测试是否代谢 Fit小鼠EGFRvIII CAR细胞在无淋巴去除宿主条件保存条件下的移植 内源性免疫。如果成功，这些方法可以在未来的研究中与以下战略相结合 增强内源性宿主对异种肿瘤的免疫并克服敌意免疫抑制 肿瘤环境。这项工作虽然是在脑瘤模型中进行的，但将与CAR T细胞治疗相关 对抗多发性实体瘤。

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.