EPITHELIAL BARRIER DYSFUNCTION AND MUCOSAL INFLAMMATION IN ASTHMA

哮喘中的上皮屏障功能障碍和粘膜炎症

• 批准号: 9130246
• 负责人: Steve N Georas
• 金额: $ 47.6万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-26 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9130246
• 关键词: Adherens Junction; Adjuvant; Allergens; Allergic; Antigens; Apical; Asthma; Attenuated; Biological Assay; Bone Marrow; Breathing; Cells; Chimera organism; Clinical; Complex; Data; Defense Mechanisms; Dendritic Cells; Dendritic cell activation; Development; Double-Stranded RNA; Employee Strikes; Endocytosis; Endotoxins; Epithelial; Epithelium; Functional disorder; Gatekeeping; Health; Immune response; Immune system; Immunization; Inflammation; Link; Lung; Measures; Modeling; Mucociliary Clearance; Mucosal Immunity; Mucositis; Mus; Ovalbumin; Permeability; Play; Reporting; Research; Respiratory Syncytial Virus Infections; Respiratory syncytial virus; Role; Sampling; Signal Pathway; Signaling Molecule; Stromal Cells; Structure; Surface; TLR3 gene; Testing; Tight Junctions; Tissues; Translational Research; Viral Respiratory Tract Infection; Work; airway inflammation; allergic airway inflammation; cytokine; human subject; in vivo; inhibitor/antagonist; insight; intraepithelial; mouse model; novel; occludin; overexpression; particle; prevent; programs; protein kinase D; radioresistant; research clinical testing; respiratory virus; sensor; uptake

DESCRIPTION (provided by applicant): The lung is constantly bombarded by inhaled particles and antigens, and has evolved numerous defense mechanisms that guard against the development of inflammation due to otherwise innocuous substances. These defense mechanisms include mucociliary clearance, the mucosal immune system, and epithelial apical junctional complexes (AJC). In recent years there have been significant advances in our understanding of junctional complex structure and function. However, most research to-date has been conducted with model epithelia and in non-pulmonary tissues, and many questions remain about the function of epithelial junctional complexes at mucosal surfaces. The relationship between barrier structure, antigen sampling by intraepithelial dendritic cells (DC), and sensing of mucosal danger needs further study. Interestingly, airway epithelial junction dysfunction is increasingly associated with asthma, but the underlying mechanisms involved and consequences for airway inflammation remain poorly understood. Furthermore, there are no good assays of outside/in airway permeability in clinical use. Here we show that Th2 cytokines, synthetic double stranded RNA (dsRNA), and respiratory syncytial virus (RSV) induce striking disassembly of airway AJC. We identified a novel signaling pathway linking dsRNA and RSV with protein kinase D (PKD) and cytoskeletal remodeling resulting in airway epithelial junction dysfunction. Very little is known about the expression and function of PKD in the lung, but emerging evidence suggests that this versatile signaling molecule may play an important role in mucosal immunity in general. We next used a mouse model of mucosal sensitization with endotoxin-free ovalbumin (Ova), which when inhaled together with the dsRNA polyI:C, results in allergic-type inflammation two weeks later following challenge with Ova alone. Using reciprocal bone marrow chimeric mice, toll-like receptor 3(TLR3) expression was required in radioresistant (stromal) cells in order for dsRNA to act as a pro-allergic inhaled adjuvant. Here we will build on these data and propose a translational research program that will provide new insights into airway epithelial barrier function and epithelial:DC cross-talk of relevance to respiratory viral infections and allergic airway inflammation. We propose four specific aims that will: (1) Define the precise roles of epithelial PKD and dsRNA sensors during mucosal sensitization, (2) Test the hypothesis occludin overexpression inhibits mucosal allergen sensitization, (3) Test the hypothesis that RSV infection causes sustained dysfunction of the airway epithelial barrier in a PKD-dependent manner, and (4) Develop the Leaky Lung Test, a clinically useful and non-invasive assay of outside/in airway permeability.

描述（由申请人提供）：肺部不断受到吸入颗粒和抗原的轰击，并且已经进化出许多防御机制，以防止由于其他无害物质而引起的炎症的发展。这些防御机制包括粘膜纤毛清除、粘膜免疫系统和上皮顶端连接复合物 (AJC)。近年来，我们对连接复合体结构和功能的理解取得了重大进展。然而，迄今为止的大多数研究都是在模型上皮和非肺组织中进行的，关于粘膜表面上皮连接复合物的功能仍然存在许多问题。屏障结构、上皮内树突状细胞（DC）抗原采样和传感之间的关系 粘膜危险需要进一步研究。有趣的是，气道上皮连接功能障碍越来越多地与哮喘相关，但所涉及的潜在机制和气道炎症的后果仍然知之甚少。此外，在临床使用中还没有良好的气道外/气道内通透性测定方法。在这里，我们发现 Th2 细胞因子、合成双链 RNA (dsRNA) 和呼吸道合胞病毒 (RSV) 会诱导气道 AJC 发生惊人的分解。我们发现了一条新的信号通路，将 dsRNA 和 RSV 与蛋白激酶 D (PKD) 和细胞骨架重塑联系起来，导致气道上皮连接功能障碍。关于 PKD 在肺部的表达和功能知之甚少，但新出现的证据表明，这种多功能信号分子可能在粘膜免疫中发挥重要作用。接下来，我们使用了不含内毒素的卵清蛋白 (Ova) 的粘膜致敏小鼠模型，当与 dsRNA polyI:C 一起吸入时，在单独使用 Ova 攻击后两周后会导致过敏型炎症。使用相互骨髓嵌合小鼠，抗辐射（基质）细胞需要 Toll 样受体 3 (TLR3) 表达，以便 dsRNA 充当促过敏吸入佐剂。在这里我们将建立在 这些数据并提出了一项转化研究计划，该计划将为气道上皮屏障功能以及与呼吸道病毒感染和过敏性气道炎症相关的上皮：DC 串扰提供新的见解。我们提出了四个具体目标：(1) 定义上皮 PKD 和 dsRNA 传感器在粘膜致敏过程中的精确作用，(2) 检验 occludin 过度表达抑制粘膜过敏原致敏的假设，(3) 检验 RSV 感染导致持续功能障碍的假设以 PKD 依赖性方式检测气道上皮屏障，以及 (4) 开发漏气肺测试，这是一种临床上有用的非侵入性气道外/气道内检测方法渗透性。