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Role of Dock8 in EAE

Dock8 在 EAE 中的作用

基本信息

批准号：
9125526
负责人：
Mohamed Oukka
金额：
$ 28.94万
依托单位：
SEATTLE CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-15 至 2018-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9125526
关键词：
Adverse effects Affect Animal Model Autoimmune Diseases Autoimmune Process Autoimmunity Binding Biological Assay C57BL/6 Mouse CD4 Positive T Lymphocytes CDC42 gene Cardiovascular Diseases Cells Central Nervous System Infections DOCK1 protein Data Demyelinations Dendritic Cells Development Disease Experimental Autoimmune Encephalomyelitis FDA approved Family Gene Deletion Guanine Nucleotide Exchange Factors Helper-Inducer T-Lymphocyte Human Hybrids Immune Immunity Inflammation Integrin alpha Chains Interleukin-10 Interleukin-6 JC Virus Knockout Mice Lesion Life Lymphocyte Lymphoid Cell Mediating Molecular Monoclonal Antibodies Monomeric GTP-Binding Proteins Mouse Strains Multiple Sclerosis Mus Myelin Myeloid Cells Neuraxis Oral Organ Pathogenesis Pharmaceutical Preparations Play Progressive Multifocal Leukoencephalopathy Protein Family Proteins Relapse Resistance Risk Role STAT3 gene Scaffolding Protein Signal Transduction T-Lymphocyte Th1 Cells Th2 Cells Tysabri Work Yeasts analog base cell motility cytokine extracellular in vivo interleukin-21 interleukin-23 lymph nodes member migration multiple sclerosis patient multiple sclerosis treatment new therapeutic target novel pathogen patient subsets prevent public health relevance rho sphingosine 1-phosphate trafficking

项目摘要

DESCRIPTION (provided by applicant): Th17 cells have emerged as potent inducers of autoimmune diseases. However, discovery of the mechanisms by which Th17 cells fulfill their pathogenic functions remains elusive. We have found that Th17 cells migrate quickly and accumulate in the CNS of C57BL/6 mice immunized with MOG35-55 prior to the onset of Experimental Autoimmune Encephalomyelitis (EAE), an animal model of MS, but decline rapidly thereafter when Th1 numbers are maintained. This raises the possibility that Th17 cells might be necessary for the recruitment of other pathogenic T cells, such as Th1 cells, after the peak of disease to perpetuate EAE progression. We found that DOCK8-deficient T cells differentiate poorly into Th17 cells. More importantly, DOCK8-deficient mice were completely resistant to the development of EAE. DOCK8 is one of 11 members of the DOCK180 family of proteins, some of which have been shown to function as guanine nucleotide exchange factors (GEFs) that bind and activate small GTPases of the Rho/Rac/Cdc42 family. Although it has been suggested that DOCK8 might coordinate cytoskeletal arrangement, cellular detachment and regulate cell migration, the precise role of the DOCK proteins in the cell remains for the most part unknown. It is possible that DOCK8 might act as a scaffolding protein that is important for the activation o unknown factors necessary for the differentiation and trafficking of Th17 cells. DOCK8 is mainly expressed in lymphocyte and myeloid cell subsets such as dendritic cells (DCs). However, to date we do not know the molecular mechanisms by which DOCK8 regulates the differentiation and the function of these various cell subsets. In order to investigate the in vivo role of DOCK8, we have generated a DOCK8-conditional knockout mouse in which DOCK8 expression could be specifically deleted in CD4 T cells, and Th17 cells. Based on our observation that DOCK8-deficient mice are resistant to the development of EAE, we postulate that DOCK8 could be a novel therapeutic target for the treatment of MS. In order to study how DOCK8 expression affects the pathogenesis of EAE, we propose to carry out the following specific aims: Aim 1. Determine the in vivo role of DOCK8-expressing cells in the development of EAE: We postulate, on the basis of preliminary studies, that DOCK8 plays a critical role in development of Th17 cells and their trafficking in vivo. We will use conditional DOCK8 knockout mice to determine how DOCK8 affects the function of Th17 cells in vivo. Aim 2. Determine the role of DOCK8 in T cell signaling: Based on our preliminary data, our working hypothesis is that signaling mediated by DOCK8 overlaps with, and may directly impact, STAT3 activation and function. We will assess in human and mouse T cells how DOCK8 contributes to cytokine-induced STAT3 activation such as IL-6, IL21, IL10 and IL-23.

描述(由申请人提供)：Th17细胞已成为自身免疫性疾病的有效诱导者。然而，Th17细胞履行其致病功能的机制仍不清楚。我们发现，在MS的动物模型实验性自身免疫性脑脊髓炎(EAE)发生之前，用MOG35-55免疫的C57BL/6小鼠的中枢神经系统中Th17细胞迅速迁移和积聚，但在Th1细胞数量保持不变时，Th17细胞迅速减少。这增加了一种可能性，即Th17细胞可能是在疾病高峰期后招募其他致病T细胞(如Th1细胞)以维持EAE进展所必需的。我们发现DOCK8缺陷的T细胞分化成Th17细胞的能力很差。更重要的是，DOCK8缺陷小鼠完全抵抗EAE的发展。DOCK8是DOCK180家族的11个成员之一，其中一些蛋白被证明具有鸟嘌呤核苷酸交换因子(GEF)的功能，可以结合和激活Rho/RAC/CDC42家族的小GTP酶。尽管DOCK8被认为可能协调细胞骨架的排列、细胞的脱离和调节细胞的迁移，但DOCK8蛋白在细胞中的确切作用仍不清楚。DOCK8可能作为一种支架蛋白，对Th17细胞分化和运输所需的未知因子的激活起重要作用。DOCK8主要表达于淋巴细胞和树突状细胞(DC)等髓系细胞亚群。然而，到目前为止，我们还不知道DOCK8调控这些不同细胞亚群分化和功能的分子机制。为了研究DOCK8在体内的作用，我们建立了DOCK8条件性基因敲除小鼠，在该小鼠中，DOCK8在CD4T细胞和Th17细胞中的表达可以被特异性地删除。基于DOCK8基因缺陷小鼠对EAE的抵抗，我们推测DOCK8可能成为治疗MS的新靶点。为了研究DOCK8表达如何影响EAE的发病机制，我们建议开展以下具体目标：目的1.确定DOCK8表达的细胞在EAE发生发展中的体内作用：在初步研究的基础上，我们假设DOCK8在Th17细胞的发育及其在体内的运输中起关键作用。我们将使用条件性DOCK8基因敲除小鼠来确定DOCK8如何在体内影响Th17细胞的功能。目的2.确定DOCK8在T细胞信号转导中的作用：根据我们的初步数据，我们的工作假设是DOCK8介导的信号转导与STAT3的激活和功能有重叠，并且可能直接影响STAT3的激活和功能。我们将在人类和小鼠T细胞中评估DOCK8如何促进细胞因子诱导的STAT3激活，如IL-6、IL-21、IL-10和IL-23。