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: 9759486
• 负责人: Megan Dacek
• 金额: $ 4.5万
• 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 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759486
• 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; 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; Immunosuppressive Agents; 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; immune checkpoint blockade; in vivo; innovation; insight; macrophage; mouse model; neoplastic cell; prevent; resistance mechanism; small molecule; success; systemic toxicity; tumor; tumor microenvironment; 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

项目总结/摘要 嵌合抗原受体（CAR）T细胞疗法重定向T细胞以激活并随后杀死抗原- 表达癌细胞。这是通过偶联癌抗原特异性细胞外单链 可变IgG片段（scFv）与胞质内内源性T细胞活化信号传导结构域的结合。CAR T细胞 治疗已显示出治疗造血系统恶性肿瘤的前景;然而，抗原阴性的造血系统恶性肿瘤的复发， 肿瘤仍然是这些患者失败的重要原因。此外，几乎没有成功， 用免疫抑制微环境治疗实体瘤。用CAR T细胞和 封锁检查站是克服这些障碍的一个可能办法。检查点阻断疗法 拮抗抑制免疫系统的信号通路。目前的检查站封锁战略 一直专注于改变T细胞与肿瘤的相互作用，但最近的研究也显示， 免疫检查点，特别是CD 47-SIRPα信号轴。这条路径被称为“不要吃我” 信号，阻止抗体介导的巨噬细胞吞噬作用和T细胞的主动交叉致敏， 树突状细胞，并因此参与抑制先天性和适应性免疫过程。癌细胞 选择了这条途径来逃避免疫攻击。然而，抗CD 47药物的早期临床试验 显示贫血和血小板减少的全身毒性。 我们的长期目标是设计一种更有效的CAR T细胞，可以克服抗原丢失复发和免疫缺陷。 免疫抑制肿瘤微环境。为了实现这一点，我们建议研究组合 CAR T细胞治疗与内在SIRPα蛋白分泌激活抗体治疗和抗原 介绍，因为这种组合应该有效地参与先天和适应性免疫，以导致更多的 完全抗肿瘤反应。我们已经改造了人类CD 19 CAR T细胞，使其分泌一种小的 分子，高亲和力，SIRPα模拟物，CV1.这些分泌CV1的CAR T细胞，称为OrexiCAR T细胞，保留了 它们的细胞毒性功能和细胞分泌的CV1可以增强mAb治疗。此外，我们还表明， 体外OrexiCART细胞的癌抗原刺激导致分泌的CV1大量增加。这里我们 我建议在完全免疫活性的同源环境中研究OrexiCAR T细胞，以确定 机制有助于其效力。我们相信，拟议的研究将有助于更好地了解 OrexiCAR T细胞功效及其临床适用性。目的：1）构建小鼠CD 19 将OrexiCAR载体转染入原代小鼠细胞，并在体外验证CAR和CV1的功能 和2）评估mOrexiCAR T细胞在免疫活性的同基因重组小鼠中的抗肿瘤作用。 小鼠模型，揭示和描述免疫机制