STAT5 tetramerization in autoimmune-mediated neuroinflammation

自身免疫介导的神经炎症中的 STAT5 四聚化

• 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
• 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' 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

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.

项目总结/摘要 多发性硬化症（MS）是一种免疫介导的疾病，影响全球约230万人， 宽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。 一种有效的多发性硬化症动物模型，实验性自身免疫性脑脊髓炎（EAE），已经被证实。 用于证明CD 4 + T细胞和单核细胞衍生细胞（MDC）之间的同源相互作用， 在此定义了树突状细胞和巨噬细胞的混合群体，其在细胞周期中从单核细胞分化而来。 自身免疫驱动的神经炎症是EAE发病机制所必需的。这个项目的总体目标是 一个建议是确定信号通路和它们的下游调节相互作用的效应介质 中枢神经系统内CD 4 + T细胞和MDCs的异常表达促进了EAE的发病。信号转导和激活剂 转录因子5A和5 B（STAT 5A和STAT 5 B）在介导以下细胞反应中起关键作用： 细胞因子、干扰素、生长因子的刺激。活化的STAT 5蛋白可以形成二聚体， 四聚体。STAT 5四聚体的生物学功能尚未完全了解。使用Stat 5a-Stat 5 b N结构域 双敲入（DKI）小鼠品系，其中不能形成STAT 5四聚体，但形成STAT 5二聚体。 在不受影响的情况下，我们发现STAT 5四聚体促进EAE的发病。DKI中的轻度EAE表型 小鼠与脊髓脑膜中CD 4 + T细胞和单核细胞/MDC的相互作用减少相关 在EAE期间。我们进一步证明了细胞因子GM-CSF激活STAT 5四聚体可以促进单核细胞 分化为树突状细胞和表达趋化因子CCL 17。相应地， 在EAE期间，DKI小鼠脊髓中的CCL 17显著减少。重要的是，接受STAT 5的小鼠 用CCL 17处理的四聚体缺陷型Th 17细胞发展出更严重的EAE，疾病发作更早 与接受没有CCL 17处理的细胞的小鼠相比。我们的中心假设是GM-CSF介导的 STAT 5四聚体对于促进致病性Th 17细胞和单核细胞/MDCs的相互作用至关重要 通过CCL 17依赖性机制在脊髓脑膜中，这些细胞相互作用是必需的， 促进EAE的发病。我们将在三个具体目标中检验我们的假设。在目标1中，我们将利用 不同的EAE诱导策略，以确定STAT 5四聚体在CD 4 + T细胞中的致病作用， 单核细胞/MDC。在目标2中，我们将测试我们的假设，即STAT 5四聚体信号转导促进 EAE期间脊髓脑膜单核细胞分化和Th 17细胞-MDC相互作用 成像技术在目的3中，我们将研究CCL 17促进肿瘤发病的机制。 EAE。具体而言，我们将检验我们的假设，即CCL 17增加了整合素LFA-1对Th 17细胞的亲和力， 从而促进Th 17细胞-MDC相互作用。靶向控制相互作用的途径和介质 CD 4 + T细胞与CNS内MDCs之间的相互作用可能成为MS治疗的新策略。