Unraveling the Pathophysiology of Neurotoxicity Induced by CAR T-cells

摘要 我们希望了解免疫治疗是如何引起神经毒性的。神经毒性是最有害的 B细胞白血病和淋巴瘤的几种免疫疗法的副作用，包括CAR T细胞疗法。在……里面 在后一种方法中，患者自身的T细胞样本被移除，通过基因工程识别B细胞- 细胞肿瘤，大量扩张，然后重新注入患者体内。基因工程肿瘤-- 识别成分是嵌合抗原受体(CAR)。汽车重新编程T细胞以识别和杀死 肿瘤细胞，而不考虑T细胞的先天特异性。抗B细胞相关抗原的CAR T细胞 CD19可以诱导其他晚期B细胞恶性肿瘤患者的持久完全缓解。喜欢 然而，任何治疗都有副作用。CD19特异性CAR T细胞经常引起一系列 神经不良反应(NAE)，从定向障碍到死亡。它们是无法预防或治疗的 这是因为人们对它们的病理生理知之甚少。为此，我们开发了一种新的免疫- 复制抗肿瘤疗效和毒性(包括NAE)的合格人源化小鼠模型 临床上由CD19特异性CAR T细胞引起。在我们的模型中，小鼠B细胞表达人CD19 转基因(HCD19Tg)。表达hCD19特异性CAR的小鼠T细胞(称为CART19细胞)的转移 进入hCD19Tg小鼠引起的NAE与临床上经历的非常相似。因为我们的发现 镜像临床报告，我们建议CART19诱导的小鼠NAE的原因将推断到患者 用CD19特异性CAR T细胞治疗。我们的中心假设是血脑屏障(BBB)的破坏 CART19输注后允许白细胞、体液和全身细胞因子进入中枢神经 系统(CNS)。在这里，这些全身性细胞因子，以及更大程度上由中枢神经系统产生的细胞因子 CART19细胞，激活驻留的小胶质细胞和渗出的髓样细胞。两者的区别在于 促炎细胞最终导致NAE。我们提出了两个目的来检验这些假说。第一个目标是 揭示是什么导致了血脑屏障功能障碍，而第二个目标将决定是什么驱动了NAE。我们将学习如何 CART19细胞跨越血脑屏障，如果它们在中枢神经系统的持续激活有助于或推动NAE。vbl.使用 遗传、免疫学和药理学方法，我们还将评估居民和 外周血髓系细胞和对NAE的特异性细胞因子。最后，我们将评估NAE如何影响 用单细胞方法研究脑实质细胞的基因和蛋白质表达。我们提议的项目 将对两个领域产生重大影响：1)与NAE相关的中枢神经系统病理生物学的基础研究；2) 与改进CD19特异性CAR T细胞对人B细胞治疗相关的翻译研究 恶性肿瘤。

ABSTRACT We wish to understand how immunotherapy-induced neurotoxicity occurs. Neurotoxicity is the most pernicious side effect of several immunotherapies for B-cell leukemias and lymphomas, including CAR T-cell therapy. In the latter approach, a sample of the patient’s own T-cells are removed, genetically engineered to recognize B- cell tumors, expanded to large numbers, and then reinfused into the patient. The genetically engineered tumor- recognition component is a chimeric antigen receptor (CAR). CARs reprogram T-cells to recognize and kill tumor cells, regardless of the T-cell’s innate specificity. CAR T-cells specific for the B-cell-associated antigen CD19 can induce durable complete remissions in patients with otherwise terminal B-cell malignancies. Like any therapy, though, it has side-effects. CD19-specific CAR T-cells frequently cause a spectrum of neurological adverse effects (NAE) ranging from disorientation to death. They cannot be prevented or treated adequately because their pathophysiology is poorly understood. To that end, we developed a novel, immune- competent humanized mouse model that replicates the anti-tumor efficacy and toxicities (including NAE) caused clinically by CD19-specific CAR T-cells. In our model, mouse B-cells express a human CD19 transgene (hCD19Tg). Transfer of mouse T-cells – called CART19 cells - that express a hCD19-specific CAR into hCD19Tg mice cause NAEs that are very similar to those experienced clinically. Because our findings mirror clinical reports, we suggest the causes of CART19-induced murine NAE will extrapolate to patients treated with CD19-specific CAR T-cells. Our central hypothesis is that blood brain barrier (BBB) disruption following CART19 infusion permits leukocytes, fluids, and systemic cytokines to enter the central nervous system (CNS). Here these systemic cytokines, and to a greater extent cytokines produced in the CNS by CART19 cells, activate resident microglial cells and extravasated myeloid cells. The differentiation of both into proinflammatory cells ultimately causes NAE. We propose two aims to test these hypotheses. The first aim will reveal what causes BBB dysfunction while the second aim will determine what drives NAE. We will learn how CART19 cells cross the BBB and if their persistent activation in the CNS contributes to or drives NAE. Using genetic, immunological, and pharmacological methods, we also will assess the contributions of resident and extravasated peripheral myeloid cells and specific cytokines to NAE. Finally, we will assess how NAE affects gene and protein expression by brain parenchymal cells using single cell approaches. Our proposed project will significantly impact two areas: 1) basic research in CNS pathobiology as it relates to NAE and 2) translational research as it relates to improving CD19-specific CAR T-cell therapy for human B-cell malignancies.