Tetraspanins in Asthma and Eosinophilic Lung Disease

描述（由申请人提供）：长期以来，人们认为嗜酸性粒细胞在哮喘和其他嗜酸性粒细胞性肺病中仅作为“终末期效应”细胞发挥作用，通过释放细胞毒性物质发挥作用。然而，越来越多的证据表明，嗜酸性粒细胞在介导气道炎症中具有重要的免疫调节作用。一个这样的公认的关键免疫调节作用是它们作为抗原呈递细胞（APC）的功能。本基金的目的是探索人类嗜酸性粒细胞表面膜上抗原呈递机制的组织。具体而言，四跨膜蛋白分子和脂筏的参与可能是重要的，允许嗜酸性粒细胞作为专业的APC。拟议研究的具体目标将调查以下假设：1）四跨膜蛋白CD9与人嗜酸性粒细胞的抗原呈递机制相关，2）MHC II类主要位于人嗜酸性粒细胞表面的脂筏中，3）CD9与人嗜酸性粒细胞脂筏中的MHC II类相关，和4）其它非CD9四跨膜蛋白与人嗜酸性粒细胞的细胞内区室中的MHC II类相关。拟开展的研究将利用免疫共沉淀、脂筏分离、免疫荧光显微镜、流式细胞术和Western印迹，以确定四跨膜蛋白和脂筏参与人嗜酸性粒细胞的抗原呈递复合物。抗原呈递蛋白、四跨膜蛋白和脂筏之间的关联的建立将进一步确立嗜酸性粒细胞作为独特的抗原呈递细胞，在哮喘的持续存在中可能具有关键的免疫调节作用。哮喘是一种影响数百万美国人的常见疾病，但对这种疾病的全面了解仍然难以捉摸。嗜酸性粒细胞是一种炎症细胞，已被发现与哮喘和其他肺部疾病有关。我们的研究旨在更好地了解嗜酸性粒细胞如何组织其表面蛋白，希望这将有助于了解它们在哮喘中的真正作用。

DESCRIPTION (provided by applicant): Eosinophils have long been thought to function exclusively as "end stage effector" cells in asthma and other eosinophilic lung disorders, acting through the release of cytotoxic substances. However, mounting evidence has demonstrated that eosinophils have important immunoregulatory roles in mediating airways inflammation. One such well-established key immunoregulatory role is their function as anitgen-presenting cells (APCs). The purpose of this grant is to explore the organization of the antigen presentation machinery on the surface membrane of human eosinophils. Specifically, the involvement of tetraspanin molecules and lipid rafts may be important in allowing eosinophils to function as professional APCs. The specific aims of the research proposed will investigate the following hypotheses: 1) the tetraspanin CD9 is associatedwith antigen-presentation machinery in human eosinophils, 2) MHC Class II Is located predominantly in lipid rafts on the cell surface of human eosinophils, 3) CD9 associates with MHC Class II in lipid rafts of human eosinophils, and 4) other non-CD9 tetraspanins associate with MHC Class II in intracellular compartments in human eosinophils. The proposed research will utilize co-immunopreciptation, lipid raft isolation, immunofluoresecence microscopy, flow cytometry, and Western blot in order to establish the involvement of tetraspanins and lipid rafts in the antigen presentation complex of human eosinophils. Establishment of the association between antigen presentation proteins, tetraspanins, and lipid rafts would further establish eosinophils as unique antigen presenation cells with a likely pivotal immunoregulatory role in the perpetuation of asthma. Asthma is a common disorder that affects millions of Americans, but a complete understanding of the disease remains elusive. Eosinophils are inflammatory cells that have been noted to be associated with asthma and other lung diseases. Our research aims to better understand how eosinophils organize their surface proteins with the hope that this will provide insight into their true role in asthma.