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

项目总结 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，以及自身免疫等疾病。适当地定位在组织内，并 与抗原提呈细胞(APC)相互作用T细胞穿过血管内皮细胞壁外渗，并 遵循组织中存在的环境线索。在这些过程中，T细胞会改变形状并延伸 需要肌动蛋白聚合的膜突起，如片状脂膜和丝状足膜。然而，几乎没有什么是 已知肌动蛋白网络重塑的特定效应分子，这是T细胞外渗和 有效地检测APC的抗原。我们的初步数据显示，细胞骨架效应蛋白 在自身免疫性炎症过程中，Ena/Vasp家族介导T细胞进入组织，包括大脑， 揭示了Ena/Vasp蛋白在T细胞外渗中的特定和先前未知的作用。 T细胞在环境提示下经历一个迁徙的“寻路”过程，以找到允许的 在间质迁移过程中，要使血管壁上的渗出部位和组织内的组织得到适当的定位。 丝状伪足可以调节对环境刺激的感觉，并被认为在T细胞中发挥作用 渗出。在神经元和其他类型的细胞中，Ena/Vasp蛋白可以在丝状足的形成中发挥作用。 然而，丝状伪足在促进T细胞外渗、间质运动和T细胞-APC方面的特殊功能 相互作用仍不清楚。我们的目标是确定EnA/Vasp蛋白介导T细胞死亡的机制 免疫监测和自身免疫性疾病期间的细胞运输和与APC的相互作用。我们 假设Ena/Vasp介导的肌动蛋白网络重构和丝足的产生是T细胞所必需的 细胞外渗、间质运动和APC检测过程中的细胞寻径。要解决这一关键差距， EnA/Vasp蛋白调控淋巴细胞通路的机制研究 我们提出了三个目标：目标1：确定Ena/Vasp蛋白在 T细胞外渗。目的2：确定Ena/Vasp蛋白在T细胞免疫监测中的作用 激活。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，我们将使用多方面的方法，包括遗传、生化和 尖端成像技术(如双光子显微镜和超分辨率显微镜)。这将是 使我们能够研究Ena/Vasp蛋白调节T细胞外渗和细胞-细胞的机制 模型系统以及体内生理环境中的相互作用。我们的工作将决定如何 Ena/Vasp介导的肌动蛋白网络重塑调节T细胞迁移、寻路和激活 外渗、免疫监视和自身免疫性疾病。我们还将确定Ena/Vasp途径是否 是在自身免疫等疾病环境中抑制T细胞激活和贩运的潜在靶点。

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.