Insulin specific T cell response shaped by diabetes protective MHC class II molecules

由糖尿病保护性 MHC II 类分子形成的胰岛素特异性 T 细胞反应

基本信息

批准号：
10444416
负责人：
AARON W MICHELS
金额：
$ 41.14万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-01-11 至 2027-03-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10444416
关键词：
Alleles Amino Acid Substitution Amino Acids Animal Model Anti-Inflammatory Agents Antigens Autoantigens Autoimmune Diabetes Autoimmune Diseases Autoimmunity B-Cell Antigen Receptor Bar Codes Binding Biological Assay Bystander Suppression CD4 Positive T Lymphocytes Cell Line Cell physiology Cells Chromogranin A Clinical Complex DNA Data Defect Development Diabetes Mellitus Disease Epitopes Event FOXP3 gene Funding Gene Expression Generations Genetic Determinism Goals HLA Antigens Health Histocompatibility Antigens Class II Human IL2RA gene Immune Inbred NOD Mice Individual Insulin Insulin-Dependent Diabetes Mellitus Interleukin-10 Knock-out Knowledge Label Lead Link Major Histocompatibility Complex Mediating Molecular Molecular Target Mus Organ Donor Pancreas Pathway interactions Patients Peptides Phenotype Population Positioning Attribute Predisposition Process Proinsulin Proliferating Regulation Regulatory T-Lymphocyte Research Resistance Risk Role Shapes Specificity T cell receptor repertoire sequencing T cell response T-Cell Receptor T-Lymphocyte TNFRSF10A gene Testing anergy antigen test antigen-specific T cells autoreactive T cell cell immortalization cytokine diabetes risk effector T cell enzyme linked immunospot assay improved insight insulin dependent diabetes mellitus onset islet lymph nodes molecular phenotype mouse model non-diabetic peripheral blood prevent response single-cell RNA sequencing therapy design

项目摘要

Project Summary The major genetic determinant in susceptibility to or protection from many autoimmune diseases reside in the human major histocompatibility complex (MHC) that contains the human leukocyte antigen (HLA) region. In type 1 diabetes (T1D), particular HLA class II alleles (e.g. DR4/DQ8) increase the risk for developing disease, whereas others (e.g., DQ6, DQB1*06:02) lead to dominant protection. MHC class II molecules function to present processed antigens to T cells, and the MHC class II−peptide−T cell receptor (TCR) forms a trimolecular complex involving the presentation of self-peptides that shape autoreactive T cell responses in autoimmunity. The goal of our studies is to bridge the gap of knowledge in diabetes-protective MHC class II molecules and insulin-specific T cell responses. Data from the last funding period indicates that T1D protective MHC class II molecules (murine IAb ≈ human DQ6) present insulin, and specifically insulin B chain amino acids 9-23 (B:9-23) to activate CD4 T cells with a regulatory phenotype (Tregs). In the NOD mouse model of spontaneous autoimmune diabetes, insulin-specific FoxP3+ Tregs are present but fail to prevent diabetes onset. The presence of IAb in addition to the NOD diabetes conferring IAg7 MHC class II abrogates all diabetes development. With fluorescent B:9-23 tetramers on each class II molecule, we are able to detect B:9-23/IAb type 1 regulatory T cells (Tr1 cells) in the pancreatic lymph nodes in NOD mice heterozygous for IAb/IAg7, while insulin-IAg7 T cells are less frequent and not activated. Similarly in non-diabetic humans with DQ6, we are able to proliferate Tregs from the peripheral blood that respond to insulin B:9-21/DQ6. Single cell RNA sequencing of these proliferated insulin-Tregs reveals a distinct Tr1 cluster that secrete the anti-inflammatory cytokine, IL-10. However, the necessity for these insulin-Tregs and mechanisms by which these cells confer diabetes resistance remains to be determined. In specific aim 1, we will determine the molecular phenotype and necessity for insulin-Tregs to protect against diabetes development in murine models with a diabetes-resistant MHC class II molecule. Specific aim 2 focuses on parallel studies in humans to identify the protective features of insulin-Tregs restricted to DQ6 and those to DQ8 in individuals with and without T1D. The successful completion of this proposal will provide insights into the function and molecular phenotype of insulin-Tregs restricted to diabetes-protective MHC class II molecules and determine their direct role in conferring diabetes protection, thus aiding the design of therapies that may improve Treg function to treat the underlying autoimmunity in T1D.

项目摘要对许多自身免疫性疾病的敏感性或保护性的主要遗传决定因素存在于人类主要的组织相容性复合物（MHC），其中包含人类白细胞抗原（HLA）区域。类型 1个糖尿病（T1D），特定的HLA II类等位基因（例如DR4/DQ8）增加了患疾病的风险，而其他人（例如DQ6，DQB1*06：02）导致了主导保护。 MHC II类分子的功能对T细胞的加工抗原，MHC II类肽T细胞受体（TCR）形成三分子复合物涉及在自身免疫性中塑造自动反应性T细胞反应的自肽。目标我们的研究是弥合糖尿病保护MHC II类分子和胰岛素特异性的知识差距 T细胞反应。上一个资金期的数据表明T1D受保护的MHC II类分子（鼠IAB≈人类 DQ6）目前胰岛素，特别是胰岛素B链氨基酸9-23（B：9-23），以用A激活CD4 T细胞调节表型（Tregs）。在赞助自身免疫性糖尿病的点头小鼠模型中，胰岛素特异性 FOXP3+ Treg存在，但无法防止糖尿病发作。除了点头糖尿病外，IAB的存在会议IAG7 MHC II级会消除所有糖尿病的发展。荧光B：每个四聚体 II类分子，我们能够检测B：9-23/IAB 1型调节性T细胞（TR1细胞） IAB/IAG7杂合的NOD小鼠中的淋巴结，而胰岛素-IAG7 T细胞的差异较低且未激活。同样，在具有DQ6的非糖尿病人中，我们能够从外周血中增殖响应胰岛素B：9-21/dq6。这些增殖的胰岛素 - 特雷格（Tregs）的单细胞RNA测序揭示了一个独特的 TR1簇分泌抗炎细胞因子IL-10。但是，这些胰岛素 - 三核的必要条件和这些细胞赋予糖尿病耐药性的机制仍有待确定。在特定目标1中，我们将确定分子表型，是胰岛素 - 三核预防糖尿病发育所必需的具有耐糖尿病的MHC II类分子的鼠模型。特定目标2着重于平行研究人类识别限于DQ6的胰岛素 - 特雷格的受保护特征，以及患有DQ8的胰岛素 - 没有T1D。该提案的成功完成将提供有关该功能和分子的见解仅限于糖尿病保护MHC II类分子的胰岛素 - 三核表型并确定其直接在会议糖尿病保护中的作用，因此有助于疗法的设计，这些疗法可以改善Treg功能以治疗 T1D中的基础自身免疫。