Tuning peptide specifities for T cell tolerance in Type 1 diabetes

调整 1 型糖尿病 T 细胞耐受性的肽特异性

• 批准号: 10503923
• 负责人: Mark S Anderson
• 金额: $ 44.95万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-06-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10503923
• 关键词: Ablation; Address; Adoptive Transfer; Affect; Affinity; Agonist; Amino Acids; Antibodies; Antigens; Autoantigens; Autoimmune Diseases; Autoimmunity; Bacterial Artificial Chromosomes; Binding; Biochemical Pathway; Blood Glucose; CD4 Positive T Lymphocytes; Cells; Characteristics; Clonal Deletion; Collaborations; Coupling; Data; Development; Diabetes Mellitus; Diabetes prevention; Disease; Disease Outcome; Epitopes; Future; Generations; Genes; Histocompatibility Antigens Class II; Immune Tolerance; Immunotherapy; Inbred NOD Mice; Insulin; Insulin-Dependent Diabetes Mellitus; Knock-in; Knowledge; Laboratories; Lead; MHC Class II Genes; Mediating; Modeling; Mus; Mutation; Pathogenicity; Peptide/MHC Complex; Peptides; Peripheral; Positioning Attribute; Prevention; Regulatory T-Lymphocyte; Role; Specificity; T-Cell Immunologic Specificity; T-Lymphocyte; T-cell receptor repertoire; TNFSF11 gene; Testing; Therapeutic; Therapeutic Intervention; Thymus Gland; Time; Transgenic Mice; Transgenic Model; Transgenic Organisms; Translations; Variant; Work; anergy; autoreactive T cell; autoreactivity; central tolerance; diabetes pathogenesis; effector T cell; experience; experimental study; genetic association; genome wide association study; immunoregulation; improved; insight; insulitis; invariant chain; mouse model; novel; peripheral tolerance; prevent; promoter; single cell sequencing; thymus transplantation; tool

Project Summary/Abstract Type 1 Diabetes (T1D) is a classical T-cell mediated autoimmune disease and substantial data implicates insulin as a dominant autoantigen in T1D disease. In the NOD mouse model of T1D, notable studies have shown that mice lacking native insulin expression, but with an altered insulin sequence to maintain blood glucose levels, are completely protected from insulitis and diabetes. Growing evidence also indicates that insulin peptide binding and orientation within MHC Class II (peptide register) is important in determining the strength of interaction and recognition by autoreactive T cells. In collaboration with the Kappler lab, we have uncovered an unusual peptide binding characteristic of the dominant insulin epitope InsB:9-23. The majority of InsB:9-23-specific CD4+ T cells in the periphery recognize insulin bound in this unusual register 3, and by knocking in a single amino acid variation (R to E) into just one copy of the insulin gene in NOD mice (Ins2EE/+), the mice are completely protected against diabetes. The development of a “super agonist” version of the insulin dominant epitopes allows us to address several key questions surrounding the biochemical pathways of peptide generation, presentation by MHC molecules, and recognitions by auto-reactive pathogenic T cells. Do mutations of the major epitope in the insulin gene allow CD4+ T effectors or Treg cells specific for these alternative epitopes to develop? Are mimotopes of these pathogenic epitopes capable of dramatically altering disease outcomes? Are we able to fine tune these epitopes to alter tolerance mechanisms to shift from deletion to Treg induction? Recent work in our lab has focused on the identification of the insulin-specific repertoire on key mouse backgrounds, and we plan to utilize these tools and well-characterized mouse models to examine the effects of altering insulin expression, thymically and extrathymically. These tools as well as our experience with the generation of numerous TCR-transgenic mouse lines will allow us to address these questions in the context of T1D. Thus, we hypothesize that alterations to epitope presentation and TCR affinity drive the tunning of the TCR repertoire towards tolerance and away from self-reactivity. Using Insulin as a model antigen, we propose to test our hypothesis through the following specific aims: Aim 1: Define the role of central tolerance upon the deletion of insulin-reactive clones Aim 2: Characterize the effects of peripheral tolerance on insulin-reactive T cells Aim 3: Explore mechanisms of dominate tolerance to understand the potential for translation into therapeutic treatments for T1D Through these experiments, we hope to gain a nuanced understanding of how changes in insulin epitopes and antigenicity drive the pathogenesis of diabetes and identify targets for future immune modulation and therapeutic intervention for T1D treatment and prevention.

项目概要/摘要 1 型糖尿病 (T1D) 是一种经典的 T 细胞介导的自身免疫性疾病，大量数据表明 胰岛素作为 T1D 疾病的主要自身抗原。在 T1D 的 NOD 小鼠模型中，著名的研究表明 缺乏天然胰岛素表达的小鼠，但通过改变胰岛素序列来维持血糖水平， 完全免受胰岛素炎和糖尿病的影响。越来越多的证据还表明胰岛素肽结合 MHC II 类（肽登记区）内的方向和方向对于确定相互作用的强度和 由自身反应性 T 细胞识别。与卡普勒实验室合作，我们发现了一种不寻常的肽 主要胰岛素表位 InsB:9-23 的结合特征。大多数 InsB:9-23 特异性 CD4+ T 细胞 外围识别在这个不寻常的寄存器 3 中结合的胰岛素，并通过敲入单个氨基酸 NOD 小鼠 (Ins2EE/+) 中胰岛素基因的一个拷贝（R 到 E）发生变异，小鼠受到完全保护 对抗糖尿病。 胰岛素优势表位“超级激动剂”版本的开发使我们能够解决几个问题 围绕肽生成、MHC 分子呈递的生化途径的关键问题， 以及自身反应性致病性 T 细胞的识别。胰岛素基因中主要表位的突变是否允许 针对这些替代表位的 CD4+ T 效应子或 Treg 细胞是否会发育？这些是模拟表吗 能够显着改变疾病结果的致病表位？我们能够微调这些表位吗 改变耐受机制，从删除转变为 Treg 诱导？我们实验室最近的工作重点是 在关键小鼠背景上鉴定胰岛素特异性库，我们计划利用这些工具 和良好表征的小鼠模型，以检查改变胰岛素表达、胸腺和胰岛素表达的影响 心外的。这些工具以及我们培育大量 TCR 转基因小鼠的经验 线将使我们能够在 T1D 的背景下解决这些问题。 因此，我们假设表位呈递和 TCR 亲和力的改变驱动了 TCR 的全部功能是趋向耐受性并远离自身反应性。使用胰岛素作为模型抗原，我们 提议通过以下具体目标来检验我们的假设： 目标 1：确定中枢耐受在胰岛素反应性克隆删除后的作用 目标 2：表征外周耐受对胰岛素反应性 T 细胞的影响 目标 3：探索主导耐受机制，以了解转化为 T1D 的治疗方法 通过这些实验，我们希望能够细致地了解胰岛素表位的变化和 抗原性驱动糖尿病的发病机制并确定未来免疫调节的目标 T1D 治疗和预防的治疗干预。