Engineering CAR T cells to potentiate innate and adaptive immunity

改造 CAR T 细胞以增强先天性和适应性免疫

• 批准号: 10115521
• 负责人: Megan Dacek
• 金额: $ 2.31万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-01 至 2021-05-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10115521
• 关键词: Adaptive Immune System; Address; Affinity; Anemia; Anti-CD47; Antibodies; Antibody Therapy; Antigen Presentation; Antigens; Antitumor Response; B lymphoid malignancy; Binding; CAR T cell therapy; CD19 gene; CD47 gene; CD47-SIRPα; CD8-Positive T-Lymphocytes; Cells; Clinic; Combined Modality Therapy; Complication; Coupling; Cross-Priming; Dendritic Cells; Engineering; Failure; Generations; Goals; Hematopoietic Neoplasms; Human; Human Engineering; Immune; Immune system; Immunocompetent; Immunoglobulin G; Immunologics; In Vitro; Lead; Malignant Neoplasms; Mediating; Monoclonal Antibody Therapy; Mus; Names; Natural Immunity; Pathway interactions; Patients; Phagocytosis; Pharmaceutical Preparations; Phase I Clinical Trials; Play; Process; Protein Secretion; Proteins; Relapse; Research; Resistance; Role; Signal Pathway; Signal Transduction; Solid Neoplasm; Source; T cell response; T cell therapy; T-Cell Activation; T-Lymphocyte; Technology; Testing; Thrombocytopenia; Toxic effect; Tumor Antigens; Variant; adaptive immunity; analog; antitumor effect; base; cancer cell; chimeric antigen receptor; chimeric antigen receptor T cells; clinical translation; clinically relevant; cytokine; cytotoxic; effective therapy; extracellular; immune checkpoint blockade; in vivo; innate immune checkpoint; innovation; insight; macrophage; mouse model; neoplastic cell; prevent; resistance mechanism; small molecule; success; systemic toxicity; tumor; tumor microenvironment; tumor-immune system interactions; vector

Project Summary/Abstract Chimeric antigen receptor (CAR) T cell therapy redirects T cells to activate and subsequently kill antigen- expressing cancer cells. This is achieved by coupling a cancer antigen-specific extracellular single-chain variable IgG fragment (scFv) to intracytoplasmic, endogenous T cell activation signaling domains. CAR T cell therapy has shown promise for treating hematopoietic malignancies; however, relapse of antigen-negative tumors remains a significant source of failure for these patients. Further, little success has been seen in treating solid tumors with immunosuppressive microenvironments. Combination therapy with CAR T cells and checkpoint blockade is a possible approach to overcome these obstacles. Checkpoint blockade therapy antagonizes the signaling pathways that suppress the immune system. Current checkpoint blockade strategies have focused on altering T cell-tumor interactions, but recent studies also show promise in abrogating innate immune checkpoints, specifically the CD47-SIRPα signaling axis. This pathway, known as the “do not eat me” signal, prevents both antibody mediated macrophage phagocytosis and active cross priming of T cells by dendritic cells, and is thus involved in suppressing both innate and adaptive immune processes. Cancer cells have co-opted this pathway to evade immune attack. However, early stage clinical trials of anti-CD47 agents show systemic toxicities of anemia and thrombocytopenia. Our long-term goal is to engineer a more potent CAR T cell that can overcome antigen loss relapse and the immunosuppressive tumor microenvironment. To accomplish this, we propose to investigate the combination of CAR T cell therapy with intrinsic SIRPα protein secretion to activate antibody therapy and antigen presentation, as this combination should potently engage both innate and adaptive immunity to lead to a more complete antitumor response. We have already engineered human CD19 CAR T cells to secrete a small molecule, high affinity, SIRPα mimic, CV1. These CV1-secreting CAR T cells, named OrexiCAR T cells, retain their cytotoxic function and the cell-secreted CV1 can potentiate mAb therapy. In addition, we have shown that cancer antigen stimulation of the OrexiCAR T cells in vitro leads to a large increase in secreted CV1. Here, we propose to study OrexiCAR T cells in a fully immunocompetent, syngeneic setting to determine which mechanisms contribute to their potency. We believe the proposed research will allow a better understanding of OrexiCAR T cell efficacy and its applicability to the clinic. The Aims are: 1) To construct mouse CD19 OrexiCAR vectors, transduce into primary mouse cells, and validate functions of CAR and CV1 in vitro and 2) To evaluate the anti-tumor effect of mOrexiCAR T cells in an immunocompetent, syngeneic mouse model and to discover and describe the immunologic mechanism

项目摘要/摘要 嵌合抗原受体(CAR)T细胞疗法重定向T细胞激活并随后杀死抗原- 表达癌细胞。这是通过偶联癌症抗原特异性的胞外单链来实现的。 可变免疫球蛋白片段(ScFv)到胞浆内，内源性T细胞激活信号域。CAR T细胞 治疗已显示出治疗血液系统恶性肿瘤的希望；然而，抗原阴性的复发 肿瘤仍然是这些患者失败的一个重要来源。此外，在以下方面收效甚微 用免疫抑制微环境治疗实体瘤。CAR T细胞和Car T细胞联合治疗 检查站封锁是克服这些障碍的一种可能办法。关卡封锁疗法 拮抗抑制免疫系统的信号通路。当前的检查站封锁战略 都专注于改变T细胞和肿瘤的相互作用，但最近的研究也显示出废除先天的希望 免疫检查点，特别是CD47Sirpα信号轴。这条小路被称为“不要吃我” 信号，阻止抗体介导的巨噬细胞吞噬和T细胞的主动交叉免疫 树突状细胞，因此参与抑制先天免疫和获得性免疫过程。癌细胞 都选择了这条途径来逃避免疫攻击。然而，抗CD47药物的早期临床试验 表现出贫血和血小板减少的全身性毒性。 我们的长期目标是设计一种更强大的CAR T细胞，它可以克服抗原丢失复发和 免疫抑制肿瘤微环境。为了实现这一点，我们建议调查这一组合 内源性Sirpα蛋白分泌激活抗体和抗原治疗CAR T细胞的研究 介绍，因为这种组合应该有效地调动先天免疫和获得性免疫，以导致更多 完全的抗肿瘤反应。我们已经改造了人类CD19汽车T细胞来分泌一小部分 分子，高亲和力，Sirpα模拟，CV1。这些分泌CV1的CAR T细胞，被称为OrexiCAR T细胞，保留 它们的细胞毒作用和细胞分泌的CV1可以加强单抗的治疗。此外，我们已经表明， 肿瘤抗原在体外刺激OrexiCAR T细胞，导致分泌的CV1大量增加。在这里，我们 建议在完全免疫活性的同基因环境中研究OrexiCAR T细胞，以确定 机制有助于它们的效力。我们相信，拟议的研究将使我们更好地了解 OrexiCAR T细胞的疗效及其在临床的适用性。目的：1)构建小鼠CD19 OrexiCAR载体，转导原代小鼠细胞，体外验证CAR和CV1的功能 2)评价mOrexiCAR T细胞在具有免疫活性的同基因小鼠体内的抗肿瘤作用。 小鼠模型的建立和免疫机制的发现与描述