Enhancing mitochondrial metabolism to improve anti-tumor CD8 immune response

摘要 CAR-T免疫疗法作为一种挽救方案对不再有效的患者有很大的前景 传统疗法。已经批准了五种CAR-T细胞疗法(四种针对癌细胞上的CD19) FDA用于治疗复发和/或难治性(r/r)B系恶性肿瘤，包括ALL，非霍奇金 淋巴瘤、慢性淋巴细胞性白血病和多发性骨髓瘤。然而，大约50%的B细胞白血病和淋巴瘤患者 CD19 CAR-T治疗后一年内复发。CAR-T疗法的成功 与几个因素有关，包括：1)CAR-T细胞移植后的初始扩增 处于IL-2缺乏环境中的患者，2)CAR-T细胞效应器功能的维持3)长期 CAR-T细胞的存活。这些T细胞生物学方面受其代谢阶段的影响很大，而CAR-T 众所周知，细胞的结果受它们的新陈代谢的影响。新陈代谢现在被认为是一种主要的 免疫细胞功能的调节因子，影响免疫反应的进程。我们有 甲基化控制的J蛋白是一种定位于线粒体内膜的蛋白质 它作为复合体I和线粒体呼吸(线粒体ATP)的内源性负调节因子 生产)。我们已经证明，CD8细胞中MCJ的丢失增加了细胞因子的分泌，并具有细胞毒作用 活动。Memory MCJ KO CD8细胞对流感病毒具有较好的保护作用。MCJ缺乏症 CD8细胞在杀死肿瘤细胞方面也更有效。因此，我们假设，消除MCJ作为一种 CD8细胞的代谢制动将导致细胞因子的产生、肿瘤杀伤活性和生存期的增加 CAR-T细胞和MCJ可能是提高CAR-T免疫治疗成功率的一个有吸引力的靶点。至 检验这一假说并显示其临床相关性，我们建议：1)评估MCJ作为调节因子的作用 人CD8细胞线粒体代谢及效应器功能的研究2)体内外评价 小鼠MCJ缺陷型CAR T细胞的效力和效率；3)构建MCJ缺陷型人CD8 CAR-T 具有更好的存活率、扩张性和细胞毒活性。

SUMMARY CAR-T immunotherapy has great promise as a salvage regimen for patients who will no longer respond to conventional therapies. Five CAR-T cell therapies (four targeting CD19 on cancer cells) have been approved by FDA for treatment of relapsed and/or refractory (r/r) B-lineage malignancies, including ALL, Non-Hodgkin Lymphoma, CLL and multiple myeloma. However, about 50% of B cell leukemia and lymphoma patients treated with CD19 CAR-T therapy relapse within a year after CAR-T therapy. The success of CAR-T therapy has been associated with several factors, including: 1) the initial expansion of CAR-T cells after transfer into the patients in an IL-2-deprived environment, 2) maintenance of the CAR-T cell effector function 3) long-term survival of CAR-T cells. These T cell biology aspects are highly influence by their metabolic stage, and CAR-T cell outcome is known to be influenced by their metabolism. Metabolism is now considered as a major regulatory factor of the function of immune cells and influences the course of an immune response. We have identified MCJ (Methylation-Controlled J protein) as a protein localized in the inner membrane of mitochondria that acts as an endogenous negative regulator of Complex I and mitochondrial respiration (mitochondrial ATP production). We have shown that loss of MCJ in CD8 cells enhances cytokine secretion as well as cytotoxic activity. Memory MCJ KO CD8 cells have superior protective activity against influenza virus. MCJ deficient CD8 cells are also more efficient in killing tumor cells. Thus, we hypothesize that eliminating MCJ as a metabolic brake in CD8 cells will result in enhanced cytokine production, tumor killing activity and survival of CAR-T cells and that MCJ could be an attractive target to improve the success of CAR-T immunotherapy. To test this hypothesis and show its clinical relevance, we propose: 1) to evaluate the role of MCJ as a regulator of mitochondrial metabolism and effector function in human CD8 cells; 2) to evaluate the in vitro and vivo potency and efficacy of mouse MCJ-deficient CAR T cells, 3) to develop an MCJ-deficient human CD8 CAR-T with improved survival, expansion and cytotoxic activity.