Cellular and Molecular Mechanisms of Regulatory T Cells in EAE

EAE 调节性 T 细胞的细胞和分子机制

• 批准号: 9301460
• 负责人: MICHAEL D CAHALAN
• 金额: $ 49.89万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-20 至 2021-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9301460
• 关键词: Agonist; Amphiregulin; Antigens; Autoimmune Diseases; Autoimmune Process; Autoimmunity; Axon; Behavior; Blood Circulation; Calcium Signaling; Cell Therapy; Cell Transplantation; Cell membrane; Cells; Communicable Diseases; Complex; Data; Demyelinations; Dendritic Cells; Disease; Disease Progression; Disease remission; Drug Targeting; Endocytosis; Endoplasmic Reticulum; Endothelium; Equilibrium; Eragrostis; Experimental Autoimmune Encephalomyelitis; Failure; Functional disorder; Goals; Healthcare; Homeostasis; Hot Spot; Human; Image; Immune; Immune Tolerance; Immune response; In Situ; In Vitro; Inflammation; Ion Channel; Lymphocyte; Lymphoid; Mediating; Microscopy; Modeling; Molecular; Monitor; Motor; Multiple Sclerosis; Mus; Nervous system structure; Neuraxis; Neurons; Oligodendroglia; Onset of illness; Pathogenesis; Pathogenicity; Phase; Physiologic pulse; Play; Preparation; Process; Proteins; Recovery; Recruitment Activity; Regulation; Regulatory T-Lymphocyte; Research Personnel; Role; STIM1 gene; Sensory; Signal Pathway; Signal Transduction; Sinus; Sphingosine-1-Phosphate Receptor; Spinal Cord; Stem cell transplant; T-Cell Activation; T-Lymphocyte; Testing; Therapeutic; Therapeutic Intervention; Therapy Evaluation; Time; Tissues; Transplantation; Visual; Work; axon injury; cell motility; cell type; cellular imaging; cognitive system; cost; effective therapy; immunoregulation; lymph nodes; migration; mouse model; nerve stem cell; neuroinflammation; novel; oligodendrocyte-myelin glycoprotein; prevent; receptor; remyelination; repaired; response; stem cell therapy; therapeutic target; trafficking; two-photon

PROJECT SUMMARY/ABSTRACT Multiple sclerosis (MS) and other autoimmune diseases constitute a major healthcare burden at a cost of >$50 billion per year. Autoimmunity arises from a failure of immunoregulation, in which regulatory T cells (Tregs) play a crucial role in balancing immune responses, though their suppressive mechanisms are incompletely understood and little is known about their cellular dynamics. Our overall goal is to identify cellular and molecular immunoregulatory mechanisms that contribute to disease progression and response to therapy. Building on our expertise in two-photon (2-P) imaging at the cellular level, and Ca2+ signaling at the molecular level, we will use the experimental autoimmune encephalomyelitis (EAE) mouse model of MS to investigate cellular interactions and molecular mechanisms underlying disease progression, as well as therapeutic approaches to promote remission. We focus in particular on Tregs, which maintain homeostasis and limit autoimmunity. Our central hypothesis is that Tregs limit autoimmune-mediated demyelination in the EAE model at two levels. (i) At the cellular level, Tregs compete with conventional T cells for access to antigen-presenting dendritic cells (DCs), and restrict egress of differentiated, pathogenic effector T cells (Teffs) from lymph nodes (LN). In Aim 1, we will apply simultaneous 2-P imaging of Tregs, naïve T cells, Teffs, and DCs in the LN to reveal fundamental cell trafficking and interaction dynamics during EAE induction, progression, and remission. Aim 2 extends those studies to the spinal cord where, by additionally imaging oligodendrocytes and neuronal cells, we will elucidate the cellular dynamics of neuroinflammation and demyelination during disease progression and remission. In both Aims, we further propose to define cellular dynamics during therapies that show great promise for treating MS in humans including drugs that target S1P1 receptors to cause lymphocyte sequestration within the LN, and stem cell therapy to promote remyelination. (ii) At the molecular level, Tregs directly contact target lymphocytes to inhibit Ca2+ signaling and suppress their activation. We have previously shown that Ca2+ signaling in T cells is mediated by plasma membrane Orai1 channels and triggered by STIM1 in the endoplasmic reticulum. In Aim 3, we propose to investigate the roles of these proteins employing a novel `toolkit' of genetically-encoded Ca2+ indicators and probes of channel function to monitor cellular Ca2+ signaling in LN and spinal cord. We hypothesize that Treg contact with naïve or effector T cells results in dissolution of Orai1 puncta and transendocytosis of Orai1 channel protein into Tregs. We will evaluate Orai1 as a therapeutic target in MS by visualizing cellular dynamics following administration of a specific Orai1 blocker during EAE and the translational potential of this approach will be validated with human cells. Although this proposal is targeted specifically to MS, our findings and novel immunoimaging approaches will contribute in a broader context to a better understanding of how immune responses are initiated, how immunological tolerance is achieved, how Tregs prevent autoimmunity and dampen immune responses, and how autoimmunity and infectious diseases can be effectively treated.

项目总结/摘要 多发性硬化症（MS）和其他自身免疫性疾病构成了主要的医疗保健负担， 每年超过500亿美元。自身免疫是由于免疫调节的失败而引起的，其中调节性T 细胞（TCFs）在平衡免疫反应中起着至关重要的作用，尽管它们的抑制机制 对它们的细胞动力学知之甚少。我们的总体目标是 确定有助于疾病进展的细胞和分子免疫调节机制 以及对治疗的反应。基于我们在细胞水平双光子（2-P）成像方面的专业知识， 和Ca 2+信号在分子水平上，我们将使用实验性自身免疫性脑脊髓炎 (EAE)MS的小鼠模型，以研究细胞相互作用和分子机制 疾病进展以及促进缓解的治疗方法。我们特别关注 维持体内平衡和限制自身免疫的激素。我们的中心假设是， EAE模型中自身免疫介导的脱髓鞘在两个水平。(i)在细胞水平上， 与传统的T细胞竞争抗原呈递树突状细胞（DC），并限制 分化的致病性效应T细胞（Tefs）从淋巴结（LN）中流出。在目标1中，我们 同时应用LN中的T细胞、初始T细胞、T细胞和DC的2-P成像，以揭示基本的 EAE诱导、进展和缓解期间的细胞运输和相互作用动力学。目的2 将这些研究扩展到脊髓，通过额外成像少突胶质细胞和神经元， 细胞，我们将阐明疾病期间神经炎症和脱髓鞘的细胞动力学 进展和缓解。在这两个目标中，我们进一步提出定义细胞动力学， 在治疗人类MS方面显示出巨大前景的疗法，包括靶向S1 P1受体的药物 以引起淋巴细胞在LN内隔离，以及干细胞疗法以促进髓鞘再生。（二） 在分子水平上，TdR直接与靶淋巴细胞接触，抑制Ca 2+信号传导， 他们的激活。我们先前已经表明，T细胞中的Ca 2+信号是由血浆介导的， 膜Orai 1通道，并在内质网中由STIM 1触发。在目标3中，我们建议 研究这些蛋白质的作用，采用一种新的基因编码的Ca 2+“工具包”， 通道功能的指示剂和探针，以监测LN和脊髓中的细胞Ca 2+信号传导。我们 假设Treg与初始或效应T细胞接触导致Orai 1斑点溶解， Orai 1通道蛋白转内吞进入TcB。我们将评估Orai 1作为治疗靶点， EAE期间给予特定Orai 1阻滞剂后通过可视化细胞动力学观察MS 并且该方法的翻译潜力将在人类细胞中得到验证。虽然这 该提案专门针对MS，我们的研究结果和新的免疫成像方法将 有助于在更广泛的背景下更好地了解免疫反应是如何启动的， 实现免疫耐受，TTRY如何预防自身免疫和抑制免疫 反应，以及如何有效地治疗自身免疫和传染病。