Structural, functional, and mechanistic anlaysis of autoreactive CD8 T cells

自身反应性 CD8 T 细胞的结构、功能和机制分析

• 批准号: 10335165
• 负责人: STEVEN C. ALMO
• 金额: $ 71.58万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-02-08 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10335165
• 关键词: Address; Alleles; Animal Model; Antigens; Area; Autoantigens; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Beta Cell; Binding; Binding Proteins; Biochemical; Biological Assay; CD8-Positive T-Lymphocytes; CD8B1 gene; Cells; Cellular biology; Chimera organism; Clone Cells; Collection; Complement; Crystallography; Cytotoxic T-Lymphocytes; Development; Disease; Disease Resistance; Disease model; Exhibits; Future; G6PC2 gene; Goals; HLA-B Antigens; Health; Histocompatibility Antigens Class I; Human; Immune system; Immunology; Inbred NOD Mice; Insulin; Insulin-Dependent Diabetes Mellitus; Islets of Langerhans; Knowledge; Learning; Ligands; MHC Class I Genes; Maps; Mediating; Mus; Mutagenesis; Nature; Pathogenicity; Pathology; Patients; Peptide/MHC Complex; Peptides; Peripheral; Play; Predisposition; Process; Property; Protein Isoforms; Reagent; Recurrence; Resistance; Role; Structure; Susceptibility Gene; T cell response; T-Cell Receptor; T-Lymphocyte; T-Lymphocyte Epitopes; Testing; Work; adaptive immune response; autoreactive T cell; autoreactivity; base; biophysical techniques; cross reactivity; cytotoxic CD8 T cells; defined contribution; high throughput screening; in vivo; in vivo Model; innovation; interdisciplinary approach; islet; mouse model; novel; pathogen; protein protein interaction; receptor; therapeutic target; tumor

ABSTRACT CD8 T cells are important contributors to the pathology observed in many autoimmune diseases, including type 1 diabetes. Despite the importance of autoreactive CD8 T cells, much fundamental knowledge is lacking in several major areas, including i) the properties of class I MHC alleles that confer susceptibility or resistance to disease; ii) the determinants that underlie the promiscuous antigen recognition often displayed by autoreactive T cells; and iii) the contribution of the CD8αβ co-receptor in facilitating autoimmune processes. These are the critical knowledge gaps that we seek to fill, and we will do so using a multidisciplinary approach and a collection of innovative strategies, reagents, and animal models. In Aim 1, we will define the biochemical and structural features and in vivo peptide presentation properties of human class I MHC alleles associated with susceptibility or resistance to type 1 diabetes. These studies will focus on HLA-B*39:06, B*39:01, and B*38:01, a closely related group of class I MHC alleles that are differentially associated with disease. We will test the hypothesis that the differential ability of these three alleles to mediate disease is the consequence of differential binding and presentation of certain disease-relevant beta cell peptides. Our newly developed NOD mouse models expressing human insulin or human IGRP will be central to this aim. In Aim 2, we will use the T cell receptors from a set of promiscuous and autoreactive CD8 T cell clones in structural and mutagenesis studies to define the mechanisms that underlie T cell receptor cross-reactivity. Among other approaches, we will take advantage of novel high-throughput assays that we have developed both to identify T cell epitopes and map protein binding interfaces. In Aim 3, we will use biochemical and biophysical approaches and in vivo models to better understand the interaction between CD8αβ and peptide-MHC. Despite the requirement of CD8αβ for CD8 T cell selection and peripheral activation, and its potential as a therapeutic target, crystallographic analysis of its interaction with pMHC is limited to a single structure of murine CD8αβ with H-2Dd. Our own findings from mouse models we have recently characterized suggest that human CD8αβ may be interacting with class I MHC in a manner not revealed by the single available structure. While autoreactive CD8 T cells under study here are likely to exhibit some unique features due to their necessity to escape tolerance mechanisms, much of what will be learned will be fundamental knowledge that is generally applicable to CD8 T cell biology and that will help guide the future development of more effective approaches to manipulate and harness the immune system in health and disease.

摘要 CD 8 T细胞是在许多自身免疫性疾病中观察到的病理学的重要贡献者， 包括1型糖尿病。尽管自身反应性CD 8 T细胞的重要性，许多基础知识， 在几个主要领域缺乏，包括i）赋予易感性的I类MHC等位基因的特性，或 对疾病的抵抗力; ii）作为混杂抗原识别的基础的决定因素，通常由 自身反应性T细胞;和iii）CD 8 αβ共受体在促进自身免疫过程中的贡献。 这些是我们寻求填补的关键知识空白，我们将采用多学科方法来填补这一空白 以及一系列创新策略、试剂和动物模型。在目标1中，我们将定义 人I类MHC等位基因的生化和结构特征以及体内肽呈递特性 与1型糖尿病的易感性或抵抗力相关。这些研究将集中在HLA-B*39：06， B*39：01和B*38：01，一组密切相关的I类MHC等位基因，它们与以下基因差异相关： 疾病我们将检验这三个等位基因介导疾病的差异能力是遗传因素的假设。 这是某些疾病相关β细胞肽的差异结合和呈递的结果。我们新 开发的表达人胰岛素或人IGRP的NOD小鼠模型将是该目标的核心。在目标2中， 我们将使用来自一组混杂和自身反应性CD 8 T细胞克隆的T细胞受体， 诱变研究，以确定T细胞受体交叉反应性的机制。除其他 方法，我们将利用新的高通量检测，我们已经开发出既鉴定T 细胞表位和MAP蛋白结合界面。在目标3中，我们将使用生物化学和生物物理 方法和体内模型，以更好地了解CD 8 αβ和肽-MHC之间的相互作用。 尽管CD 8 αβ需要CD 8 T细胞选择和外周活化，但其作为免疫调节剂的潜力仍然存在。 治疗靶点，其与pMHC相互作用的晶体学分析仅限于单一结构， 小鼠CD 8 αβ与H-2Dd。我们最近对小鼠模型的研究表明， 人CD 8 αβ可能与I类MHC相互作用，其作用方式不是单一可用结构所揭示的。 虽然本文研究的自身反应性CD 8 T细胞可能表现出一些独特的特征， 为了避免容忍机制，我们将学到的大部分知识都是基础知识， 一般适用于CD 8 T细胞生物学，这将有助于指导未来开发更有效的 在健康和疾病中操纵和利用免疫系统的方法。