Adaptive epigenetic mechanisms of beta and immune cells in autoimmune diabetes

自身免疫性糖尿病中β细胞和免疫细胞的适应性表观遗传机制

基本信息

批准号：
10279176
负责人：
Kevan C Herold
金额：
$ 71.28万
依托单位：
YALE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-07-15 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10279176
关键词：
ATAC-seq Adoptive Transfer Affect Antigens Appearance Attenuated Autoimmune Autoimmune Diabetes Autoimmune Responses Autoimmunity Beta Cell Biological Models Bone Marrow Transplantation CRISPR/Cas technology Cell Survival Cells Clinical DNA Binding DNMT3a Data Development Diabetes Mellitus Diagnosis Dioxygenases Disease Enzymes Epigenetic Process Exposure to Follow-Up Studies Gene Expression Genes Glucose Goals Human Hyperglycemia Immune Immunologics Immunotherapy In Vitro Inbred NOD Mice Individual Inflammation Inflammatory Insulin Insulin-Dependent Diabetes Mellitus Investigation Islet Cell Laboratories Lead Mediating Modeling Modification Mus Normal Cell Onset of illness Pathogenicity Pathway interactions Patients Play Prediabetes syndrome Predisposition Production RNA analysis Residual state Resistance Risk Role Sampling Signal Transduction Site T-Lymphocyte Testing Time Tissues Transplantation Work assault autoimmune pancreatitis autoimmune pathogenesis base cell killing chronic autoimmune disease clinical Diagnosis cytokine diabetogenic embryonic stem cell epigenome epigenomics human embryonic stem cell immune activation immunogenicity improved in vivo inhibitor/antagonist islet mouse model novel novel strategies prevent programmed cell death ligand 1 response single cell analysis stem transcription factor transcriptome transcriptomics

项目摘要

Project Summary Type 1 diabetes (T1D) is a chronic autoimmune disease that lead to the destruction of insulin producing β cells over a period of years before clinical presentation and afterwards. However, not all β cells are killed since follow- up studies of individuals with long standing T1D have identified residual insulin production even years after the onset of disease. The premise of this work, based on these and other observations, is that there are adaptive responses of the β cells to the immunologic attack that may prevent their destruction. We previously found that some β cells undergo “dedifferentiation”, express lower levels of β cell transcription factors, have reduced immunogenicity, and are protected from killing. The overall goal of this proposal is to identify adaptive changes in β cells and use this information to enhance their survival in the setting of immune attack. We found that there was increased expression of modifiers of the epigenome such as DNMT3a and Tet2 in human and murine β cells in vitro, during exposure to inflammatory cytokines, or in vivo during autoimmunity. We found increased expression of TET2 in β cells in islets from humans with autoimmune pancreatitis and T1D in nPOD samples. However, from our analysis of β cells during diabetes progression in NOD mice, those that resist autoimmune killing have decreased expression of Tet2. Tet2 induces hydroxymethylation of methylated CpG site which is the first step in converting a repressive to permissive epigenetic mark. We created Tet2-/- NOD mice and in adoptive transfer studies, bone marrow transplants and direct cultures with inflammatory cytokines and diabetogenic immune cells showed that deletion of Tet2 prevents autoimmune killing of β cells. Our data indicates that the Tet2-deficient β cells are not only resistant to immune killing but also modify the autoimmune responses. We hypothesize that Tet2 can modify β cells and affect their susceptibility to autoimmune killing and plan to test this hypothesis in murine model systems and human cells. We will analyze on a single cell basis the transcriptome and epigenome (by ATACseq) of β cells from WT and Tet2-/- mice. We will identify the DNA binding sequences of Tet2 in β cells. To specifically identify the role of Tet2 in β cells and determine the relationship between timing of Tet2 expression and susceptibility to killing we will create mice with tissue specific deletion of Tet2 and induce the deletion at times throughout the development of T1D. We will analyze the differences in immune cells in Tet2 sufficient and -/- mice. In the 2nd aim we will analyze TET2 expression and associated gene expression and epigenetic signatures in human samples from nPOD, patients with autoimmune pancreatitis, and control subjects. Finally, we will assess the role of TET2 expression in human embryonic stem cell-derived- β cells with and without TET2 expression in vitro and after transplantation into mice. These studies will determine the mechanisms whereby TET2 can control β cell responses to immune attack and may identify a pathway to prevent their destruction that is applicable to clinical settings.

项目概要 1 型糖尿病 (T1D) 是一种慢性自身免疫性疾病，会导致产生胰岛素的 β 细胞遭到破坏然而，在临床表现之前和之后的几年内，并非所有 β 细胞都被杀死。对长期患有 T1D 的个体的最新研究发现，即使在发病数年后，仍有残留的胰岛素产生。基于这些和其他观察，这项工作的前提是存在适应性。我们之前发现，β细胞对免疫攻击的反应可能会阻止其破坏。一些β细胞经历“去分化”，表达较低水平的β细胞转录因子，减少了该提案的总体目标是识别适应性变化。我们发现，β细胞中存在这些信息，并利用这些信息来增强它们在免疫攻击中的存活率。表观基因组修饰因子（例如 DNMT3a 和 Tet2）在人类和小鼠体内的表达增加 β 我们发现，在体外、暴露于炎性细胞因子期间或在体内的自身免疫期间细胞增加。 nPOD 样本中患有自身免疫性胰腺炎和 T1D 的人类胰岛 β 细胞中 TET2 的表达。然而，根据我们对 NOD 小鼠糖尿病进展过程中 β 细胞的分析，那些抵抗自身免疫的β细胞 Tet2 的表达降低会诱导甲基化 CpG 位点的羟甲基化。将抑制性表观遗传标记转变为宽容性表观遗传标记的第一步，我们创建了 Tet2-/- NOD 小鼠并在收养体内。转移研究、骨髓移植以及炎症细胞因子和糖尿病原性直接培养免疫细胞表明，Tet2 的缺失可以防止 β 细胞的自身免疫杀伤。 Tet2缺陷的β细胞不仅能抵抗免疫杀伤，还能改变自身免疫反应。培养出 Tet2 可以修饰 β 细胞并影响其对自身免疫杀伤的敏感性，并计划对此进行测试小鼠模型系统和人类细胞中的假设我们将在单细胞的基础上分析转录组。我们将鉴定 WT 和 Tet2-/- 小鼠 β 细胞的表观基因组（通过 ATACseq）。 Tet2在β细胞中的作用明确Tet2在β细胞中的作用并确定时间关系。为了研究 Tet2 表达和杀伤敏感性，我们将创建具有组织特异性删除 Tet2 的小鼠，并诱导在 T1D 的发展过程中有时会出现缺失，我们将分析 Tet2 中免疫细胞的差异。在第二个目标中，我们将分析 TET2 表达和相关基因表达以及 nPOD、自身免疫性胰腺炎患者和对照人类样本中的表观遗传特征最后，我们将评估 TET2 表达在人胚胎干细胞衍生的 β 细胞中的作用。这些研究将确定在体外和移植到小鼠体内后没有 TET2 表达。 TET2 可以控制 β 细胞对免疫攻击的反应的机制，并可能确定预防的途径它们的破坏适用于临床环境。