Role of Ezrin in Macrophages

项目摘要 巨噬细胞（MΦs）杀死微生物，吞噬死细胞和碎片，并调节免疫反应。 因此，它们是组织健康的守门人，包括肺部。肺组织驻留MΦ（TR-MΦ）是 间质和肺泡MΦ，它们具有互补但不同的功能。为了应对感染， 肺中Ly 6C+循环单核细胞的波迅速聚集。与TR-MΦ一致，这些 单核细胞抵抗感染，然后促进炎症反应的消退。许多慢性肺 炎症性疾病，包括囊性纤维化（CF），与MΦ功能失调有关。我们长久以来- 长期目标是了解不同的肺MΦ群如何促进肺过度炎症， 感染，并阐明这些不同的细胞群体的生物学。这项建议的目的是 表征ezrin在单核细胞/MΦ功能中的作用。我们的中心假设是ezrin控制单核细胞/MΦ 皮质肌动蛋白组织和信号转导事件响应炎症/感染刺激。这些 细胞变化允许MΦ扩散、移动、吞噬和存活，从而形成了数量级， 肺部对感染的免疫反应的质量。这些研究的基本原理是，低水平的埃兹蛋白 在CF患者的MΦ中发现（我们自己的工作）。其他调查人员也报告说， 哮喘患者的血细胞水平。因此，通过阐明埃兹林的分子机制， 改变肺MΦ功能，我们可以确定肺部疾病的潜在治疗靶点。我们的具体目标 目的1）Ezrin是单核细胞/MΦ适应炎症肺所必需的 微环境;（目的2）埃兹林是有效吞噬金黄色葡萄球菌所必需的， 铜绿假单胞菌，CF患者未能有效地从肺部根除的两种微生物; (Aim 3）功能性CFTR，突变时导致CF的基因，需要保持正常的ezrin水平 在MΦ激活期间。贡献是显着的，因为很少有人知道ezrin的作用，在调节 肺MΦ激活。我们提出的研究是创新的，因为我们将使用前所未有的小鼠模型 其中ezrin在单核细胞和MΦ中被特异性敲除。因此，拟议的研究将调查 深入研究了肺部感染和炎症过程中单核细胞和MΦ中埃兹蛋白丢失的后果。

PROJECT SUMMARY Macrophages (MΦs) kill microorganisms, engulf dead cells and debris, and regulate the immune response. They are thus gatekeepers of tissue health, including the lungs. The lung-tissue-resident MΦs (TR-MΦs) are the interstitial and alveolar MΦs, which have complementary but distinct functions. In response to infections, lungs are rapidly populated by waves of Ly6C+ circulating monocytes. In concert with TR-MΦs, these monocytes fight the infection, then facilitate resolution of the inflammatory response. Many chronic lung inflammatory diseases, including cystic fibrosis (CF), are associated with dysregulated MΦ function. Our long- term goal is to understand how different lung MΦ populations contribute to lung hyper-inflammation and infection, and to elucidate the biology of these distinct cell populations. The objective of this proposal is to characterize ezrin’s role in monocyte/MΦ function. Our central hypothesis is that ezrin controls monocyte/MΦ cortical actin organization and signal transduction events in response to inflammatory/infectious stimuli. These cellular changes allow the MΦs to spread, move, phagocytize, and survive, thus shaping the magnitude and quality of the lung immune response to infections. The rationale for these studies is that low ezrin levels have been found in MΦs from patients with CF (our own work). Other investigators have also reported low ezrin levels in blood cells from individuals with asthma. Thus, by elucidating the molecular mechanism by which ezrin shapes lung MΦ functions, we could identify potential therapeutic targets for lung diseases. Our specific aims will test the following hypotheses: (Aim 1) ezrin is necessary for monocyte/MΦ adaptation to the inflamed lung microenvironment; (Aim 2) ezrin is needed for efficient phagocytosis of Staphylococcus aureus and Pseudomonas aeruginosa, two microorganisms that CF patients fail to efficiently eradicate from their lungs; (Aim 3) functional CFTR, the gene that causes CF when mutated, is needed to preserve normal ezrin levels during MΦ activation. The contribution is significant since very little is known about ezrin’s role in regulating lung MΦ activation. Our proposed research is innovative because we will use an unprecedented mouse model in which ezrin is knocked out specifically in monocytes and MΦs. Thus, the proposed studies will investigate in depth the consequences of ezrin loss in monocytes and MΦs during lung infection and inflammation.