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

基本信息

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
项目类别：
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

项目摘要

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，大量数据表明值得注意的研究表明，胰岛素是 T1D 疾病中的主要自身抗原。小鼠缺乏天然胰岛素表达，但具有维持血糖水平的胰岛素序列，越来越多的证据还表明，胰岛素肽结合可以完全预防胰岛素炎和糖尿病。 MHC II 类（肽寄存器）内的方向和方向对于确定相互作用的强度和通过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 细胞的识别是否允许胰岛素基因中主要表位的突变。 CD4+ T 效应子或 Treg 细胞对这些替代表位具有特异性，它们是模拟表位吗？能够显着改变疾病结果的致病表位我们是否能够微调这些表位？改变耐受机制以从删除转变为 Treg 诱导？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特征良好的小鼠模型来检查改变胰岛素表达、胸腺和胰岛素表达的影响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，我们研究表位呈递和 TCR 亲和力的改变驱动 TCR 的调节。我们使用胰岛素作为模型抗原，使 TCR 趋于耐受并远离自身反应。提议通过以下具体目标来检验我们的假设：目标 1：定义中枢耐受在删除胰岛素反应性克隆时的作用目标 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。