STAT5 tetramerization in autoimmune-mediated neuroinflammation

自身免疫介导的神经炎症中的 STAT5 四聚化

基本信息

批准号：
10627016
负责人：
EDWIN CHI KEUNG WAN
金额：
$ 26.6万
依托单位：
WEST VIRGINIA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-07 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10627016
关键词：
Active Immunization Adoptive Transfer Affinity Animal Model Antibodies Antigen-Presenting Cells Autoimmune Biological Assay Biological Process Blocking Antibodies CCL17 gene CD4 Positive T Lymphocytes Cell Communication Cells Complex Cytokine Activation Demyelinations Dendritic Cells Disease Experimental Autoimmune Encephalomyelitis Extravasation Freund&apos s Adjuvant Gene Expression Profile Goals Granulocyte-Macrophage Colony-Stimulating Factor Growth Factor ITGAX gene Imaging Techniques Immune In Vitro Infiltration Inflammation Integrin Binding Integrins Interferons Interleukin-17 Knock-in Knock-in Mouse Lead Mediating Mediator of activation protein Meningeal Meninges Monitor Mouse Strains Multiple Sclerosis Mus Myeloid Cells N Domain Neuraxis Onset of illness Pathogenesis Pathogenicity Pathway interactions Persons Phenotype Play Population Reporter Role Signal Pathway Signal Transduction Spinal Cord Stat5 protein Testing Tumor-infiltrating immune cells Work axonal degeneration cell type chemokine cytokine dimer early onset effective therapy in vivo insight intravital imaging macrophage monocyte multiple sclerosis treatment neuroinflammation novel novel strategies response young adult

项目摘要

Project Summary/Abstract Multiple sclerosis (MS) is an immune-mediated disease that impacts approximately 2.3 million people world- wide. MS is caused by the activation and the complex interactions between different immune cell types that cause inflammation in the central nervous system (CNS), which leads to demyelination and axonal degeneration. A validated animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE), has been utilized to demonstrate that the cognate interactions between CD4+ T cells and monocyte-derived cells (MDCs), defined here a mixed population of dendritic cells and macrophages differentiated from monocytes during the autoimmune-driven neuroinflammation, are required for the pathogenesis of EAE. The overall goal of this proposal is to identify signaling pathways and their downstream effector mediators that regulate the interactions of CD4+ T cells and MDCs within CNS that promote the pathogenesis of EAE. Signal transducers and activators of transcription 5A and 5B (STAT5A and STAT5B) play a critical role in mediating cellular responses following stimulation of cytokines, interferons, growth factors. The activated STAT5 proteins can form dimers and tetramers. The biological functions of STAT5 tetramers are not fully understood. Using a Stat5a-Stat5b N-domain double knock-in (DKI) mouse strain, in which STAT5 tetramers cannot be formed but STAT5 dimers are unaffected, we found that STAT5 tetramers promote the pathogenesis of EAE. The mild EAE phenotype in DKI mice correlates with reduced interactions of CD4+ T cells and monocytes/MDCs in the spinal cord meninges during EAE. We further demonstrated that STAT5 tetramer activation by cytokine GM-CSF promotes monocyte differentiation into dendritic cells and the expression of chemokine CCL17. Correspondingly, the expression of CCL17 in the spinal cords is significantly reduced in DKI mice during EAE. Importantly, mice receiving STAT5 tetramer-deficient Th17 cells treated with CCL17 developed more severe EAE with earlier onset of the disease compared with mice receiving cells without CCL17 treatment. Our central hypothesis is that GM-CSF-mediated STAT5 tetramerization is critical for facilitating the interactions of pathogenic Th17 cells and monocytes/MDCs in the spinal cord meninges via a CCL17-dependent mechanism, and these cell interactions are required to promote the pathogenesis of EAE. We will test our hypothesis in three specific aims. In Aim 1, we will utilize different EAE induction strategies to determine the pathogenic role of STAT5 tetramers in CD4+ T cells and monocytes/MDCs during EAE. In Aim 2, we will test our hypothesis that STAT5 tetramer signaling promotes monocyte differentiation and Th17 cell-MDC interactions at the spinal cord meninges during EAE using intravital imaging technique. In Aim 3, we will investigate the mechanism by which CCL17 promotes the pathogenesis of EAE. Specifically, we will test our hypothesis that CCL17 increases the affinity of integrin LFA-1 on Th17 cells, thereby facilitates Th17 cell-MDC interactions. Targeting the pathways and mediators that control the interactions between CD4+ T cells and MDCs within CNS may become a novel strategy for the treatments of MS.

项目概要/摘要多发性硬化症 (MS) 是一种免疫介导的疾病，影响着全世界约 230 万人。宽的。 MS 是由不同免疫细胞类型之间的激活和复杂相互作用引起的引起中枢神经系统（CNS）炎症，导致脱髓鞘和轴突变性。一种经过验证的多发性硬化症动物模型——实验性自身免疫性脑脊髓炎（EAE）用于证明 CD4+ T 细胞和单核细胞衍生细胞 (MDC) 之间的同源相互作用，这里定义了从单核细胞分化而来的树突状细胞和巨噬细胞的混合群体自身免疫驱动的神经炎症是 EAE 发病机制所必需的。本次活动的总体目标提议是确定信号通路及其调节相互作用的下游效应介质 CNS 内的 CD4+ T 细胞和 MDC 促进 EAE 的发病机制。信号转换器和激活器转录 5A 和 5B（STAT5A 和 STAT5B）在介导细胞应答中发挥着关键作用刺激细胞因子、干扰素、生长因子。激活的 STAT5 蛋白可以形成二聚体并四聚体。 STAT5 四聚体的生物学功能尚未完全了解。使用 Stat5a-Stat5b N 域双敲入（DKI）小鼠品系，其中不能形成 STAT5 四聚体，但形成 STAT5 二聚体不受影响，我们发现 STAT5 四聚体促进 EAE 的发病机制。 DKI 中的轻度 EAE 表型小鼠脊髓脑膜中 CD4+ T 细胞和单核细胞/MDC 相互作用减少相关在 EAE 期间。我们进一步证明细胞因子 GM-CSF 激活 STAT5 四聚体可促进单核细胞分化为树突状细胞并表达趋化因子 CCL17。相应地，表达式为 EAE 期间 DKI 小鼠脊髓中的 CCL17 显着减少。重要的是，接受 STAT5 的小鼠用 CCL17 处理的四聚体缺陷型 Th17 细胞出现更严重的 EAE，且发病更早与接受未经 CCL17 处理的细胞的小鼠相比。我们的中心假设是 GM-CSF 介导 STAT5 四聚化对于促进致病性 Th17 细胞和单核细胞/MDC 的相互作用至关重要通过 CCL17 依赖性机制在脊髓脑膜中，这些细胞相互作用是促进EAE的发病机制。我们将在三个具体目标上检验我们的假设。在目标 1 中，我们将利用不同的 EAE 诱导策略以确定 STAT5 四聚体在 CD4+ T 细胞中的致病作用 EAE 期间的单核细胞/MDC。在目标 2 中，我们将检验我们的假设，即 STAT5 四聚体信号传导促进使用活体细胞技术研究 EAE 期间脊髓脑膜处的单核细胞分化和 Th17 细胞-MDC 相互作用成像技术。在目标3中，我们将研究CCL17促进疾病发病的机制。 EAE。具体来说，我们将测试我们的假设，即 CCL17 增加整合素 LFA-1 对 Th17 细胞的亲和力，从而促进 Th17 细胞-MDC 相互作用。针对控制相互作用的途径和介质中枢神经系统内 CD4+ T 细胞和 MDC 之间的研究可能成为治疗多发性硬化症的新策略。