Role of disrupted ASL pH regulation in small airways in CF lung disease pathogenesis

项目摘要/摘要 囊性纤维化是一种常见的遗传性疾病，由囊性纤维化的跨膜传导缺陷引起。 调整器(CFTR)。CF肺部疾病的发病机制尚不清楚，也存在争议，至少部分原因是 缺乏合适的CF动物模型的研究。此外，大多数关于发病机制的研究都依赖于 来自培养的人类病变的大型近端呼吸道的数据，例如气管和支气管组织。然而， 病理和临床资料表明，该病始发于直径<2 mm的小气道。 爱荷华州的一家研究小组已经将cftr基因的缺失或突变改造成猪。这些猪模仿人类的CF，包括 自发性感染和呼吸道粘液和炎性细胞阻塞。这 该模型为研究肺纤维化的发病机制提供了前所未有的契机。我们的 本研究的目的是探讨CFTR的缺失如何导致小气道的宿主防御缺陷 上皮细胞和IF病毒载体介导的CFTRcDNAs对CF小气道的保护作用 缺陷。我们的总体假设是，AAV4介导的CFTR传递将纠正ASL属性并恢复 慢性支气管炎小气道上皮细胞的宿主防御功能。在目标1中，我们将使用AAV4在 培养CF猪小气道上皮细胞，检测ASL特性，包括pH、粘度和 细菌杀灭能力。在目标2中，我们将使用来自CF患者的人小气道上皮细胞来测试 假设。在目标3中，我们将检测aav4介导的基因递送的细胞趋向性和效率。 活体猪和人肺组织的小气道上皮细胞。拟议的研究将导致更好的 了解CFTR介导的宿主防御机制，并说明潜在的重要至今 小气道上皮细胞在慢性阻塞性肺疾病发病机制中的作用未被充分认识。

PROJECT SUMMARY / ABSTRACT Cystic fibrosis (CF) is a common genetic disease caused by a defect in the CF transmembrane conductance regulator (CFTR). The pathogenesis of CF lung disease is unclear and controversial, at least partially due to lack of studies in an appropriate CF animal model. In addition, most studies regarding the pathogenesis rely on data from cultured human diseased large proximal airways, such as tracheal and bronchial tissue. However, pathological and clinical data suggest that the disease is initiated in small airways with a diameter <2mm. Iowa group has engineered pigs with deletion or mutation of CFTR. These pigs mimic human CF, including development of spontaneous infections and obstruction of airways with mucus and inflammatory cells. This model provides an unprecedented opportunity to investigate the pathogenesis of CF lung disease. Our objective for this study is to investigate how loss of CFTR leads to host defense defects in CF small airway epithelia and if viral vector mediated delivery of CFTR cDNA to CF small airways will rescue host defense defects. Our overall hypothesis is that AAV4 mediated delivery of CFTR will correct ASL properties and restore host defense function of small airway epithelium in CF. In Aim 1, we will use AAV4 to deliver CFTR cDNA in cultured small airway epithelial cells from CF pigs and examine ASL properties including pH and viscosity and bacterial killing abilities. In Aim 2, we will use human small airway epithelia from CF patients to test the hypothesis. In Aim 3, we will examine the cellular tropism and efficiency of AAV4 mediated gene delivery to small airway epithelium in live pigs and human lung explant. The proposed studies will lead to a better understanding of the CFTR-mediated host defense mechanisms and illustrate a potentially important yet previously underappreciated role of small airway epithelial cells in pathogenesis of CF lung disease.