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.

项目摘要/摘要 多发性硬化症（MS）是一种免疫介导的疾病，影响了大约230万人的世界 - 宽的。 MS是由激活和不同免疫细胞类型之间的复杂相互作用引起的 引起中枢神经系统（CNS）的炎症，导致脱髓鞘和轴突变性。 经过验证的多发性硬化症的动物模型，实验性自身免疫性脑脊髓炎（EAE） 用来证明CD4+ T细胞与单核细胞衍生细胞（MDC）之间的同源相互作用， 这里定义的树突状细胞和巨噬细胞的混合种群与单核细胞区分开 自身免疫性驱动的神经炎症是EAE发病机理所必需的。总体目标 建议是确定调节相互作用的信号通路及其下游效应介质 CNS中CD4+ T细胞和MDC的促进EAE发病机理。信号传感器和激活器 转录5a和5b（STAT5A和Stat5b）在介导细胞反应中起关键作用 刺激细胞因子，干扰素，生长因子。活化的STAT5蛋白可以形成二聚体，并且 四聚体。 STAT5四聚体的生物学功能尚不完全了解。使用STAT5A-STAT5B N域 双重敲入（DKI）小鼠应变，其中STAT5四聚体无法形成，但Stat5二聚体为 未受影响，我们发现STAT5四聚体促进了EAE的发病机理。 DKI中的轻度EAE表型 小鼠与脊髓脑膜中CD4+ 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STAT5四聚体会促进单核细胞 分化为树突状细胞和趋化因子CCL17的表达。相应地，表达 在EAE期间，DKI小鼠中脊髓中的CCL17显着降低。重要的是，接收STAT5的小鼠 用CCL17处理的四聚体缺乏Th17细胞发展出更为严重的EAE，并且早期发作 与接收未经CCL17治疗的细胞的小鼠相比。我们的中心假设是GM-CSF介导 STAT5四聚体对于促进致病性TH17细胞和单核细胞/MDC的相互作用至关重要 在脊髓脑膜中通过CCL17依赖机制，这些细胞相互作用需要 促进EAE的发病机理。我们将以三个特定目标来检验我们的假设。在AIM 1中，我们将使用 不同的EAE诱导策略来确定CD4+ T细胞中Stat5四聚体的致病作用 EAE期间的单核细胞/MDC。在AIM 2中，我们将测试STAT5四聚体信号促进的假设 在EAE期间，单核细胞分化和Th17细胞-MDC相互作用在EAE期间使用浸润 成像技术。在AIM 3中，我们将研究CCL17促进的发病机理的机制 伊。具体而言，我们将测试我们的假设，即CCL17增加了整联蛋白LFA-1对Th17细胞的亲和力，即 从而促进了Th17细胞-MDC相互作用。针对控制相互作用的途径和介体 CNS中CD4+ T细胞和MDC之间可能成为MS治疗的新策略。