B Cells and Type 1 Diabetes

B 细胞和 1 型糖尿病

基本信息

批准号：
9104150
负责人：
John C Cambier
金额：
$ 32.51万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-20 至 2017-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9104150
关键词：
Address Affect Affinity American Antigen Presentation Antigen Receptors Antigens Autoantibodies Autoimmune Diseases Autoimmunity B-Cell Activation B-Lymphocytes Bone Marrow CD4 Positive T Lymphocytes Cell physiology Cell surface Cells Clinical Trials Development Diabetes Mellitus Diabetic mouse Disease Educational process of instructing First Degree Relative Flow Cytometry Frequencies Gene Transfer Techniques Goals Heavy-Chain Immunoglobulins Human Immune Immune Tolerance Immune system Inbred NOD Mice Individual Injury Insulin Insulin-Dependent Diabetes Mellitus Knowledge Laboratories Lymphoid MS4A1 gene Mediating Modeling Mus Organ Pancreas Peripheral Phenotype Population Predisposition Role Signal Pathway Spleen Surface T-Lymphocyte Techniques Testing To autoantigen Treatment Efficacy Work adaptive immunity anergy base cell type central tolerance diabetic diabetic patient diabetogenic functional status insulin dependent diabetes mellitus onset magnetic beads non-diabetic novel prevent research study targeted treatment therapeutic effectiveness

项目摘要

DESCRIPTION (provided by applicant): Autoimmunity affects nearly ten million Americans and, for unknown reasons, is increasing in frequency. Available evidence indicates that autoimmune diseases arise due to a combination of genetically determined susceptibility and innate immune stimulation, which conspire to stimulate adaptive immunity to self. Underpinning autoimmunity is the breakdown of immune tolerance to self in T cell and/or B cell compartments. While a great deal is known about the mechanisms that maintain B cell tolerance, we understand little about the mechanisms that cause it to fail in autoimmunity. In this application we propose to study mechanisms operative in loss of B cell tolerance to insulin in murine and human Type 1 Diabetes, a disease known to require B cells that are thought to function by antigen presentation to CD4 T cells. Our approach will build upon our previous work defining signaling pathways operative in maintaining antigen unresponsiveness of anergic B cells. We will analyze by flow cytometry changes in the status of insulin-specific B cells isolated using a novel magnetic bead-based approach from normal, prediabetic and diabetic mice and patients. In some cases immunoglobulin heavy chain transgenesis will be used to generate a diverse antigen receptor repertoire that is nonetheless enriched in insulin-specific cells. Aim 1 will explore how peripheral insulin-specific B cells are silenced in normal mice and whether this silencing is breached in diabetic mice. In Aim 2 we will study the role of antigen receptor affinit for insulin in determining mode of silencing, fate and diabetogenic potential. This will involve a retrotransgenic approach to generate a repertoire with defined antigen receptor affinity for insulin. In Aim 3 we will extend studies to the human, comparing insulin-specific B cells in prediabetic and diabetic individuals to non-diabetic first- degree relatives. Finally, in Aim 4 we will assess the therapeutic efficacy in T1D of a novel B cell desensitizing therapy, comparing this therapy to anti-CD20, which depletes B cells. The experiments will address the overarching hypothesis that in Type 1 Diabetes the silence of high affinity insulin-specific B cells is broken and these cells promote disease by presentation of autoantigen to CD4 T cells.

描述（由申请人提供）：自身免疫影响着近千万美国人，并且由于未知的原因，其频率正在增加。现有证据表明，自身免疫性疾病的产生是由于遗传决定的易感性和先天免疫刺激的结合，两者共同刺激了对自身的适应性免疫。自身免疫的基础是 T 细胞和/或 B 细胞区室对自身免疫耐受的破坏。虽然我们对维持 B 细胞耐受性的机制了解很多，但我们对导致其自身免疫失败的机制知之甚少。在本申请中，我们建议研究小鼠和人类 1 型糖尿病中 B 细胞对胰岛素耐受性丧失的机制，这种疾病已知需要 B 细胞通过向 CD4 T 细胞呈递抗原来发挥作用。我们的方法将建立在我们之前定义信号通路的工作基础上，这些信号通路可维持无反应性 B 细胞的抗原无反应性。我们将通过流式细胞术分析使用新型磁珠方法从正常、糖尿病前期和糖尿病小鼠和患者中分离出的胰岛素特异性 B 细胞的状态变化。在某些情况下，免疫球蛋白重链转基因将用于产生多样化的抗原受体库，但该库在胰岛素特异性细胞中富集。目标 1 将探索正常小鼠中外周胰岛素特异性 B 细胞如何沉默，以及糖尿病小鼠中这种沉默是否被破坏。在目标 2 中，我们将研究胰岛素抗原受体亲和力在决定沉默模式、命运和潜在糖尿病潜力中的作用。这将涉及逆转录转基因方法来产生具有确定的胰岛素抗原受体亲和力的库。在目标 3 中，我们将研究扩展到人类，将糖尿病前期和糖尿病个体与非糖尿病一级亲属的胰岛素特异性 B 细胞进行比较。最后，在目标 4 中，我们将评估新型 B 细胞脱敏疗法对 T1D 的治疗效果，并将该疗法与消耗 B 细胞的抗 CD20 疗法进行比较。这些实验将解决一个总体假设，即在 1 型糖尿病中，高亲和力胰岛素特异性 B 细胞的沉默被打破，这些细胞通过向 CD4 T 细胞呈递自身抗原来促进疾病。