Immunobiology of Corneal Antigen-Presenting Cells

项目概述本提案的总体目标是为首席研究员（PI）提供成为独立研究人员所需的经验和技能，重点研究免疫细胞运输机制。我的长期职业目标是建立一个全面和独立的研究项目，致力于解剖免疫细胞在炎症性和感染性角膜疾病中的运输机制，从而找到新的治疗靶点。角膜抗原呈递细胞（APC）在维持角膜清晰度和保持视力方面起着至关重要的作用。APC介导的免疫应答需要APC和T细胞之间的接触依赖信息交换。成熟DC向幼稚T细胞呈递Ag可诱导T细胞活化并增殖为效应T细胞，而效应T细胞反过来被认为受多种机制控制，包括调节性T细胞（Treg）的作用。APC的职业决策是由APC和T细胞表面的分子调控的。尽管APC在免疫系统中处于独特的位置，但它们进入角膜所需的信号，以及它们离开角膜所需的线索，在很大程度上仍未被探索。在本项目前期工作中，我们建立了一种新的多光子活体显微镜（MP-IVM）模型来研究麻醉小鼠完整角膜的APC。这种成像方法使用转基因小鼠，其中APC亚群表达不同的遗传编码荧光标签，并在亚细胞分辨率下产生APC的3D延时电影，与周围细胞相互作用。这些细胞将被用来研究引导它们进入正常角膜和发炎角膜的交通信号，并将用于解决以下三个具体目标：剖析APC进入正常角膜和发炎角膜的分子机制；2)。分析正常情况下和炎症时APC从角膜向局部淋巴结迁移的机制；3)研究角膜移植后供体和宿主APC的时空和行为特征及其与淋巴结T细胞的相互作用。这个目标还将分析效应T细胞或treg如何进入角膜。本实验将对不同APC亚群在正常状态和炎症状态下的行为异同进行全面的、机制导向的调查。

DESCRIPTION (provided by applicant): Project Summary The overall goal of this proposal is to provide the principal investigator (PI) with the experiences and skills necessary to become an independent researcher, with the focus on studying immune cell trafficking mechanisms. My long-term career goal is to establish a comprehensive and independent research program dedicated to dissect the trafficking mechanism of immune cells in inflammatory and infectious corneal disease, leading to new therapeutic targets. Corneal antigen-presenting cells (APC) have a critical role in maintaining the clarity of the cornea and preserving vision. APC-mediated immune responses require contact-dependent information exchange between APC and T cells. Ag presentation by mature DC to naive T cells induces T cell activation and proliferation into effector T cells, which is in turn thought to be controlled by several mechanisms, including the action of regulatory T cells (Treg). Career decisions taken by APC are regulated molecules on the surface of APC and T cells. Despite their unique position in the immune system, the signals APC need to enter the cornea, and the clues they require to leave the cornea, are still largely unexplored. In preliminary work for this project, we have developed a new multiphoton intravital microscopy (MP-IVM) model to study APC in intact corneas of anesthetized mice. This imaging approach uses transgenic mice, in which APC subsets expresses distinct genetically encoded fluorescent tags, and produces 3D time-lapse movies of APC at subcellular resolution, interacting with surrounding cells. These cells will be studied to investigate the traffic signals that guide them to normal and inflamed corneas and will be used to address the following three specific aims: 1.) To dissect the molecular mechanisms by which APC travel to normal and inflamed corneas; 2.) To analyze the mechanisms involved in migration of APC from the cornea to local lymph nodes under normal conditions and during inflammation; and 3) examine the spatial, temporal and behavioral characteristics of donor and host APC after corneal transplantation and their interaction with T cells in lymph nodes. This aim will also analyze how effector T cells or Tregs enter the cornea. The proposed experiments will generate a comprehensive, mechanism-oriented survey of the behavioral similarities and differences between distinct APC subsets under normal condition and inflammation. PUBLIC HEALTH RELEVANCE: Project Narrative: Identification of critical pathways of immune cell migration to and from the cornea from the proposed studies will provide new molecular targets for pharmacological intervention in inflammatory, infectious, and autoimmune corneal diseases, as well as in corneal transplantation. These targets may lead to novel and highly specific strategies for immunotherapy, through modulation of immune cell trafficking.