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

• 批准号: 10451626
• 负责人: Kevan C Herold
• 金额: $ 67.91万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 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/10451626
• 关键词: ATAC-seq; Adoptive Transfer; Affect; Antigens; Appearance; Attenuated; Autoimmune; Autoimmune Diabetes; Autoimmune Responses; Autoimmunity; B-Cell Acute Lymphoblastic Leukemia; 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; islet; mouse model; novel; novel strategies; prevent; programmed cell death ligand 1; response; single cell analysis; stem; transcription factor; transcriptome; transcriptomics

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.

项目摘要 1型糖尿病（T1D）是一种慢性自身免疫性疾病，导致胰岛素产生β细胞的破坏 在临床表现之前和之后的几年中。但是，并非所有β细胞都被杀死，因为 对具有长期T1D的个体的研究已经确定 疾病发作。基于这些和其他观察的这项工作的前提是有自适应 β细胞对免疫攻击的反应可能会阻止其破坏。我们以前发现 某些β细胞经历“脱脂”，表达较低水平的β细胞转录因子，已减少 免疫原性，并受到保护。该提案的总体目标是确定自适应变化 在β细胞中，并使用此信息来增强其在免疫攻击的情况下的生存。我们发现那里 在人和鼠β中增加了表观基因组的改性剂，例如DNMT3A和TET2 细胞在体外，暴露于炎性细胞因子或自身免疫期间的体内。我们发现增加了 来自患有自身免疫性胰腺炎和NPOD样品中T1D的人类胰岛中TET2的表达。 但是，从我们对NOD小鼠糖尿病进展过程中β细胞的分析，那些抗自身免疫的细胞 杀戮的表达降低。 TET2诱导甲基化CpG位点的羟甲基，这是 将反射性转换为允许表观遗传标记的第一步。我们创建了TET2 - / - 点头小鼠，并在自适应中创建了 转移研究，骨髓移植和具有炎症细胞因子和糖尿病性的直接培养物 免疫细胞表明，TET2的缺失可防止β细胞自身免疫性杀死。我们的数据表明 TET2缺陷型β细胞不仅对免疫杀伤具有抵抗力，而且还改变了自身免疫反应。我们 假设TET2可以改变β细胞并影响其自身免疫性杀伤的敏感性并计划对此进行测试 鼠模型系统和人类细胞中的假设。我们将单个单元格分析转录组 来自WT和TET2 - / - 小鼠的β细胞的表观基因组（Atacseq）。我们将确定DNA结合序列 β细胞中的TET2。要明确识别TET2在β细胞中的作用并确定时间之间的关系 TET2表达和对杀死的敏感性，我们将创建具有TET2的组织特异性缺失的小鼠和影响 在整个T1D开发过程中，有时会删除。我们将分析TET2中免疫细胞的差异 足够和 - / - 小鼠。在第二个目标中，我们将分析TET2表达和相关的基因表达以及 来自NPOD的人类样本，自身免疫性胰腺炎患者和对照的表观遗传学特征 主题。最后，我们将评估TET2表达在人类胚胎干细胞衍生的β细胞中的作用 并且没有TET2在体外和移植后没有TET2表达。这些研究将确定 TET2可以控制β细胞对免疫攻击的反应的机制，并可能确定预防途径 它们的破坏适用于临床环境。