Enhancing Treg Therapeutic Efficacy in GVHD with CARs

利用 CAR 增强 GVHD 中 Treg 的治疗功效

• 批准号: 10684897
• 负责人: Sara Bolivar Wagers
• 金额: $ 2.79万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-13 至 2024-07-12
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10684897
• 关键词: Adoptive Transfer; African American; Alleles; Allogenic; Antigen Presentation; Antigen-Presenting Cells; Antigens; Antitumor Response; Autoimmune; B lymphoid malignancy; B-Cell Lymphomas; B-Lymphocytes; Blood; Bone Marrow; CD19 gene; CD28 gene; Cells; Cellular biology; Clinical Research; Cyclophosphamide; Cytolysis; Cytotoxic T-Lymphocytes; Data; Disease; Disparate; Dose; FDA approved; Fluorescence; Frequencies; Genome engineering; Goals; Graft Rejection; Granzyme; HLA-A2 Antigen; Hematologic Neoplasms; Hematological Disease; Hematopoietic Stem Cell Transplantation; Hispanic; Human; Immune; Immune response; Immunosuppression; Immunotherapy; In Vitro; Infection; Inflammatory; Infusion procedures; Knock-out; Knockout Mice; Laboratories; Left; Leukemic Cell; Lymphoma cell; Malignant - descriptor; Malignant Neoplasms; Measures; Mediating; Modeling; Morbidity - disease rate; Mus; Non-Malignant; Organ; Organ Transplantation; Outcome; Patient-Focused Outcomes; Patients; Pediatric Oncologist; Phase; Physicians; Predisposition; Prevention; Production; Property; Receptor Signaling; Recurrent tumor; Regulatory T-Lymphocyte; Reporter; Reproducibility; Research Proposals; Scientist; Second Primary Cancers; Severity of illness; Solid; T cell therapy; T-Cell Activation; T-Cell Depletion; T-Cell Receptor; T-Lymphocyte; Testing; Therapeutic; Transgenes; Transplant Recipients; Transplantation; Transplantation Immunology; Treatment Efficacy; Tumor Antigens; bioluminescence imaging; bone marrow failure syndrome; cell killing; chimeric antigen receptor; chimeric antigen receptor T cells; clinical translation; comparison control; curative treatments; cytokine; cytokine release syndrome; design; disorder prevention; graft versus host disease induction; graft vs host disease; graft vs leukemia effect; high risk; human imaging; improved; in vivo; infection risk; mortality; mouse model; novel; novel strategies; novel therapeutics; perforin; preclinical study; prevent; prophylactic; rat orphan nuclear receptor NR4A1; response; secondary lymphoid organ; side effect; skills; transplant model

1 Project Summary/Abstract 2 3 Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative option for many hematological disorders 4 but its efficacy is limited by graft-versus-host disease (GVHD), a leading cause of morbidity and mortality after 5 HSCT. With current prophylactic measures 20-70% of HSCT patients develop GVHD and are left susceptible to 6 infection, tumor recurrence, and secondary malignancies. Pre-clinical and clinical studies show adoptive transfer 7 of regulatory T cells (Treg) is highly effective at preventing GVHD. Clinical translation has been hindered by low 8 Treg frequency in the blood, variable suppressive capacity of polyclonal Tregs, and the need to infuse high doses 9 to reproducibly suppress disease. Antigen-specific Tregs have been shown to be more potent than polyclonal 10 Tregs in autoimmune models and in solid organ transplants where HLA-A2 specific Tregs are given to suppress 11 responses against HLA-A2 disparate grafts. While this approach targets one of the most commonly mismatched 12 antigens, HLA-A2 is present in only 20% of African American and 34% of Hispanic patients. To overcome these 13 limitations, I will use chimeric antigen receptors (CAR) to redirect Tregs towards human CD19 (hCD19) B cells 14 using an FDA approved construct containing the 4-1BB co-stimulatory domain (CAR19). Unexpectedly, my 15 preliminary data with CAR19 Tregs demonstrate dual and opposing properties of GVHD suppression and killing 16 of leukemia cells including graft-versus-leukemia (GVL). Thus, my goal is to use Tregs specific for hCD19 present 17 on malignant B cells to mediate GVL and on non-malignant B cells to deplete these host antigen presenting cells 18 during the critical GVHD induction phase. I will use a murine major MHC mismatch model where recipient mice 19 express hCD19 on B cells. My preliminary studies demonstrate CAR19 Tregs improve GHVD survival and cause 20 hCD19 B cell depletion early after HSCT. We also found CAR19 Tregs mediate targeted killing of hCD19 21 lymphoma cells in vitro and maintained GVL in vivo unlike control Tregs. Understanding how CAR19 Tregs utilize 22 cytolysis for GVL while suppressing GVHD will help expand our understanding of CAR Treg biology and design 23 to maximize their use in allo-HSCT. I hypothesize CAR19 Tregs are bifunctional in their ability to suppress 24 excessive and deleterious immune responses (GVHD, CRS) and concurrently induce GVL effects. The findings 25 from this research proposal will elucidate the mechanisms by which CAR19 Tregs confer higher protection than 26 control Tregs or even CAR19 T cells at ameliorating GVHD, preventing cytokine release syndrome (CRS), and 27 uniquely promoting anti-tumor responses. The novel approach of redirecting CAR Tregs to tumor antigens opens 28 a new therapeutic avenue to prevent GVHD and improve allo-HSCT outcomes.

1 项目概要/摘要 2 3 异基因造血干细胞移植（HSCT）是许多血液疾病的治疗选择 4 但其功效受到移植物抗宿主病 (GVHD) 的限制，移植物抗宿主病是术后发病和死亡的主要原因 5 造血干细胞移植。根据目前的预防措施，20-70% 的 HSCT 患者会出现 GVHD，并且容易受到 6感染、肿瘤复发和继发性恶性肿瘤。临床前和临床研究显示过继转移 7 调节性 T 细胞 (Treg) 对于预防 GVHD 非常有效。临床转化受到低水平的阻碍 8 血液中 Treg 频率、多克隆 Tregs 的可变抑制能力以及输注高剂量的需要 9 可重复地抑制疾病。抗原特异性 Tregs 已被证明比多克隆更有效 自身免疫模型和实体器官移植中的 10 个 Tregs，其中 HLA-A2 特异性 Tregs 被给予抑制 11 针对 HLA-A2 不同移植物的反应。虽然这种方法针对最常见的不匹配之一 12 种抗原中，HLA-A2 仅存在于 20% 的非洲裔美国人和 34% 的西班牙裔患者中。为了克服这些 13个限制，我将使用嵌合抗原受体（CAR）将Tregs重定向到人CD19（hCD19）B细胞 14 使用 FDA 批准的包含 4-1BB 共刺激结构域 (CAR19) 的构建体。没想到，我的 CAR19 Tregs 的 15 个初步数据证明了 GVHD 抑制和杀伤的双重且相反的特性 16 种白血病细胞，包括移植物抗白血病 (GVL)。因此，我的目标是使用 hCD19 特异的 Tregs 17 在恶性 B 细胞上介导 GVL，在非恶性 B 细胞上消耗这些宿主抗原呈递细胞 18 在关键的 GVHD 诱导阶段。我将使用小鼠主要 MHC 错配模型，其中受体小鼠 19 在 B 细胞上表达 hCD19。我的初步研究表明 CAR19 Tregs 可以改善 GHVD 的存活率和病因 20 HSCT 后早期 hCD19 B 细胞耗竭。我们还发现 CAR19 Tregs 介导 hCD19 的靶向杀伤 与对照 Tregs 不同，体外研究了 21 淋巴瘤细胞并在体内维持了 GVL。了解 CAR19 Tregs 如何利用 22 GVL细胞溶解同时抑制GVHD将有助于扩大我们对CAR Treg生物学和设计的理解 23 最大限度地发挥其在异基因造血干细胞移植中的应用。我假设 CAR19 Tregs 具有双功能，能够抑制 24 过度和有害的免疫反应（GVHD、CRS）并同时诱发 GVL 效应。研究结果 该研究提案中的第 25 条将阐明 CAR19 Tregs 比其他 Treg 赋予更高保护的机制 26 控制 Tregs 甚至 CAR19 T 细胞可改善 GVHD，预防细胞因子释放综合征 (CRS)，以及 27 独特地促进抗肿瘤反应。将 CAR Tregs 重定向至肿瘤抗原的新方法开启 28 预防 GVHD 和改善异基因造血干细胞移植结果的新治疗途径。