Mechanism of B-cell Delivered Tolerance in Diabetes

B 细胞在糖尿病中传递耐受的机制

• 批准号: 7369887
• 负责人: David William Scott
• 金额: $ 31.2万
• 依托单位: UNIVERSITY OF MARYLAND BALTIMORE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7369887
• 关键词: Ablation; Adoptive Transfer; Age; Allogenic; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autologous; B-Cell Activation; B-Lymphocytes; Binding; Biological Assay; CD4 Positive T Lymphocytes; Cells; Chimeric Proteins; Complementary therapies; Condition; Data; Dendritic Cells; Diabetes Mellitus; Disease; Engineering; Epitopes; Etiology; Experimental Autoimmune Encephalomyelitis; Female; Foundations; Funding; Future; Generations; Goals; Graft Survival; Haplotypes; Hemophilia A; Immune Tolerance; Immunoglobulin G; Inbred NOD Mice; Incidence; Injection of therapeutic agent; Insulin; Islets of Langerhans Transplantation; Kinetics; Knowledge; Length; Lymphocyte; Lymphocytic choriomeningitis virus; Maintenance; Minor; Modeling; Mus; National Institute of Diabetes and Digestive and Kidney Diseases; Natural regeneration; Nature; Numbers; Patients; Personal Satisfaction; Pre-Clinical Model; Principal Investigator; Process; Production; Protocols documentation; Retroviral Vector; Role; Serum; Specificity; System; T-Cell Receptor; T-Lymphocyte; T-Lymphocyte Epitopes; T-Lymphocyte Subsets; Technology; Testing; Tissues; Transgenic Mice; Transgenic Organisms; Transplantation; Uveitis; Week; base; cellular targeting; clinical efficacy; clinically relevant; congenic; cytokine; diabetes mellitus therapy; diabetic; gene therapy; in vivo; islet; male; polypeptide; prevent; programs; protein B; research study; response; scaffold; therapeutic gene

DESCRIPTION (provided by applicant): The major goal of our lab has been to utilize a platform technology of retrovirally-delivered gene therapy for tolerance induction in autoimmune diseases, with a focus on Type 1 diabetes. These studies are based on the tolerogenicity of Ig carriers and B-cell presentation of processed T-cell epitopes. During the last decade, we have engineered multiple epitope-containing polypeptides in frame on a murine lgG1 heavy chain scaffold, and expressed them in B cells to achieve the induction and long-term maintenance of immune tolerance through continuous in vivo presentation of relevant epitopes. Data in several experimental autoimmune models are highly promising in that significant clinical efficacy has been achieved. Thus, processing and presentation of Ig fusion proteins by B cells can both prevent and reverse autoimmune responsiveness in uveitis and EAE. Importantly, we have found that expression of full length GAD65 (GAD- Ig) and insulin B9-23-lg (or pro-insulin-lg) in NOD B cells significantly delayed the onset of diabetes in female NOD mice even when treatment was started at 7-12 weeks of age (i.e., in mice with peri-insulitis). Our hypothesis is that the fusion GAD-lg is processed by NOD B cells (both male and female) for tolerogenic presentation of both major and minor GAD epitopes, and leads to the generation of T regulatory cells. Herein, we will determine the optimal conditions for B-cell activation and the mechanism of this "tolerance". We also will directly establish whether this gene therapeutic approach targets CD4 and CDS T cells or both in terms of cytokine production to multiple epitopes, as well as their ability to transfer diabetes to NOD-scid recipients. We will follow the fate of target T cells using TCR transgenic lines recognizing CD4 or CDS epitopes. Moreover, we will examine the role and specificity of regulatory T cells may be involved in both the induction and maintenance of tolerance in direct ablation and cell mixing experiments, as well as determine the role of suppressive cytokines in tolerance. Importantly for future therapy, we also wish to provide proof of principle for the efficacy of this system in an islet transplantation model. Our aims are: 1) To optimize and determine the targets of B-cell delivered gene therapy for tolerance, 2) To identify the cellular targets and mechanism of B-cell delivered gene therapy. 3) To examine the fate of pathogenic T cells and the role of regulatory T cells after B-cell delivered gene therapy, and 4) To establish the efficacy of B-cell delivered gene therapy in an islet transplant model. The accomplishment of the aims will establish the role of regulatory T cells, as well as the cellular targets for B-cell delivered gene therapy for tolerance. Our goal is to modulate pathogenic responses to GAD, for example, as a prelude to applying this protocol as a complementary

描述（由申请人提供）：我们实验室的主要目标是利用逆转录病毒基因治疗平台技术来诱导自身免疫性疾病的耐受性，重点关注 1 型糖尿病。这些研究基于 Ig 载体的耐受原性和加工过的 T 细胞表位的 B 细胞呈递。在过去的十年中，我们在鼠IgG1重链支架上构建了多个含有表位的多肽，并在B细胞中表达它们，通过体内持续呈递相关表位来实现免疫耐受的诱导和长期维持。几个实验性自身免疫模型的数据非常有希望，因为已经取得了显着的临床疗效。因此，B 细胞对 Ig 融合蛋白的加工和呈递可以预防和逆转葡萄膜炎和 EAE 中的自身免疫反应。重要的是，我们发现，即使开始治疗，NOD B 细胞中全长 GAD65 (GAD-Ig) 和胰岛素 B9-23-Ig（或胰岛素原-Ig）的表达也能显着延迟雌性 NOD 小鼠糖尿病的发病7-12 周龄时（即患有胰岛周围炎的小鼠）。我们的假设是，融合体 GAD-Ig 由 NOD B 细胞（男性和女性）处理，以产生主要和次要 GAD 表位的耐受性，并导致 T 调节细胞的产生。在此，我们将确定 B 细胞激活的最佳条件以及这种“耐受”的机制。我们还将直接确定这种基因治疗方法是否针对 CD4 和 CDS T 细胞或同时针对多个表位的细胞因子产生，以及它们将糖尿病转移给 NOD-scid 受体的能力。我们将使用识别 CD4 或 CDS 表位的 TCR 转基因系来追踪靶 T 细胞的命运。此外，我们将研究调节性T细胞在直接消融和细胞混合实验中可能参与耐受性的诱导和维持的作用和特异性，并确定抑制性细胞因子在耐受性中的作用。对于未来的治疗重要的是，我们还希望为该系统在胰岛移植模型中的功效提供原理证明。我们的目标是：1) 优化和确定 B 细胞递送基因治疗的耐受性靶点，2) 确定 B 细胞递送基因治疗的细胞靶点和机制。 3) 检查 B 细胞递送基因治疗后致病性 T 细胞的命运和调节性 T 细胞的作用，以及 4) 确定 B 细胞递送基因治疗在胰岛移植模型中的功效。这些目标的实现将确立调节性 T 细胞的作用，以及 B 细胞传递的耐受性基因治疗的细胞靶标。例如，我们的目标是调节对 GAD 的致病反应，作为应用该协议作为补充的前奏。