Regulation of T Cell Extravasation and Activation by Ena/Vasp Proteins

项目摘要 淋巴细胞在组织内的进入和迁移在免疫监视和执行中起着关键作用 效应器功能，以及疾病，如自身免疫。在组织内适当定位， 与抗原呈递细胞（APC）相互作用T细胞渗出穿过血管内皮细胞壁， 跟随组织中存在的环境线索。在这些过程中，T细胞改变形状， 膜突起，例如片状伪足和丝状伪足，需要肌动蛋白聚合。然而， 已知T细胞外渗所必需的肌动蛋白网络重塑的特定效应物， 有效地检测抗原的APC。我们的初步数据表明，细胞骨架效应蛋白的细胞骨架效应蛋白， Ena/Vasp家族在自身免疫性炎症期间介导T细胞进入组织，包括大脑， 揭示了Ena/Vasp蛋白在T细胞外渗中的特异性和先前未知的作用。 T细胞经历迁移的“寻路”过程，遵循环境线索， 在间质迁移过程中，可沿血管壁沿着定位外渗部位并适当地定位在组织内。 丝状伪足可以介导对环境刺激的感受，并被认为在T细胞中起作用。 外渗在神经元和其他细胞类型中，Ena/Vasp蛋白可以在丝状伪足形成中发挥作用。 然而，丝状伪足在促进T细胞外渗、间质运动和T细胞APC方面的特异性功能尚不清楚。 相互作用仍不清楚。我们的目标是确定Ena/Vasp蛋白介导T细胞增殖的机制。 在免疫监视以及自身免疫性疾病期间细胞运输和与APC的相互作用。我们 假设Ena/Vasp介导肌动蛋白网络重塑和丝状伪足的产生是T 外渗过程中的细胞路径发现、间质运动和APC的检测。为了解决这一关键差距， 了解Ena/Vasp蛋白在淋巴细胞过程中调节寻路的机制 目的1：确定Ena/Vasp蛋白在免疫系统中的作用， T细胞外渗。目的2：确定Ena/Vasp蛋白在T细胞免疫监视中的作用， activation.目的3：确定Ena/Vasp蛋白在自身反应性T细胞向中枢转运中的作用。 神经系统和自身免疫反应。 为了实现我们的目标，我们将采用多方面的方法，包括遗传，生物化学和 尖端成像技术（如双光子显微镜和超分辨率显微镜）。这将 使我们能够研究Ena/Vasp蛋白调节T细胞外渗和细胞-细胞粘附的机制。 模型系统以及体内生理环境中的相互作用。我们的工作将决定 Ena/Vasp介导的肌动蛋白网络重塑调节T细胞迁移、寻路和活化 外渗、免疫监视和自身免疫性疾病。我们还将确定Ena/Vasp通路是否 是抑制T细胞活化和在疾病环境如自身免疫中运输的潜在靶点。

Project summary Lymphocyte entry and migration within tissues play a critical role in immune surveillance and execution of effector functions, as well as in diseases such as autoimmunity. To properly localize within tissues and interact with antigen presenting cells (APCs) T cells extravasate across the vascular endothelial cell wall and follow environmental cues present in the tissues. During these processes, T cells change shape and extend membrane protrusions such as lamellipodia and filopodia, which require actin polymerization. However, little is known about the specific effectors of actin network remodeling necessary for T cell extravasation and to efficiently survey APCs for antigen. Our preliminary data show that the cytoskeletal effector proteins of the Ena/Vasp family mediate T cell entry into tissues, including the brain during autoimmune inflammation, revealing a specific and previously unknown role for Ena/Vasp proteins in T cell extravasation. T cells undergo a migratory `pathfinding' process following environmental cues to find permissive extravasation sites along vascular walls and to properly localize within tissues during interstitial migration. Filopodia can mediate sensing of environmental stimuli and have been suggested to play a role in T cell extravasation. In neurons and other cell types, Ena/Vasp proteins can play a role in filopodia formation. However, the specific functions of filopodia in promoting T cell extravasation, interstitial motility, and T cell-APC interactions remain unclear. Our goal is to determine the mechanisms by which Ena/Vasp proteins mediate T cell trafficking and interactions with APCs during immune surveillance as well as autoimmune disease. We hypothesize that Ena/Vasp-mediated actin network remodeling and generation of filopodia are required for T cell pathfinding during extravasation, interstitial motility, and surveying of APCs. To address this key gap in the understanding of the mechanisms by which Ena/Vasp proteins regulate pathfinding during lymphocyte trafficking and immune surveillance, we propose three aims: Aim 1: Determine the role of Ena/Vasp proteins in T cell extravasation. Aim 2: Determine the role of Ena/Vasp proteins in T cell immune surveillance and activation. Aim 3: Determine the role of Ena/Vasp proteins in self-reactive T cell trafficking to the Central Nervous System and in autoimmune responses. To accomplish our aims, we will use a multi-faceted approach including genetic, biochemical and cutting-edge imaging techniques (such as 2-photon microscopy and super-resolution microscopy). This will allow us to investigate the mechanisms by which Ena/Vasp proteins regulate T cell extravasation and cell-cell interactions in model systems as well as in physiological environments in vivo. Our work will determine how Ena/Vasp-mediated actin network remodeling regulates T cell migration, pathfinding and activation during extravasation, immune surveillance and autoimmune disease. We will also determine if the Ena/Vasp pathway is a potential target to inhibit T cell activation and trafficking in disease settings such as autoimmunity.