MECHANISMS OF CHRONIC AIRWAY DISEASE INDUCED BY VIRAL BRONCHIOLITIS

这项研究的长期目标是使用动物模型来识别 决定抗性的基因控制的分子机制和 对病毒引起的肺结构和肺结构异常的易感性 导致持续性呼吸道阻塞的功能和 高反应性(哮喘的特征)。这些功能异常 在婴儿期病毒性毛细支气管炎的儿童中检测到 由呼吸道合胞病毒和副流感病毒引起。 遗传性易感人群副流感1型(仙台)病毒感染 (BN)和抗性(F344)大鼠被用作低血压的动物模型 婴儿期的呼吸道疾病。实验假设是 经检测，病毒性毛细支气管炎在早期生命中遗传- 易感人群诱导呼吸道细胞因子基因加重 导致细支气管生长和呼吸道改变的表达 炎症细胞的数量和功能在诱导持续呼吸道中的作用 梗阻和高反应性。建议的具体目标 研究内容为：L)利用Northern分析和原位杂交技术 确定病毒易感的BN大鼠是否有细胞因子基因增加 转化生长因子-β1在肿瘤中的表达 肿瘤坏死因子-α、白介素3和/或干细胞因子 (SCF)在仙台病毒感染后和细支气管生长之前 异常和高反应性；2)使用蛋白质印迹分析和 免疫细胞化学检测淋巴细胞亚群是否增强 BN大鼠对仙台病毒诱导的生长异常的易感性是 由于抗病毒免疫反应效率较低(CD8淋巴细胞和抗病毒 HN抗体)，而不是F344大鼠；3)表征病毒诱导的 细支气管和细支气管肥大细胞二十烷基类代谢的改变 高效液相色谱法和酶联免疫测定法； 以及4)利用育种研究来确定抗性和 大鼠对病毒引起的呼吸道异常和 高反应性遗传于多基因或单纯性孟德尔 图案。这种研究方法的长期目标将是使用 简单序列长度多态和计算机分析以识别 包含控制病毒易感性的基因的基因组片段- 诱发的呼吸道异常。

The long-term goal of this research is to use an animal model to identify genetically controlled molecular mechanisms that determine resistance and susceptibility to viral- induced abnormalities in pulmonary structure and function that result in persistent airway obstruction and hyperresponsiveness (features of asthma). These functional abnormalities have been detected in children following viral bronchiolitis in infancy caused by respiratory syncytial virus and parainfluenza virus. Parainfluenza type 1 (Sendai) virus infection in genetically-susceptible (BN) and resistant (F344) rats is being used as an animal model of lower respiratory illness during infancy. The experimental hypothesis being tested is that viral bronchiolitis during early life in genetically- susceptible individuals induces accentuated airway cytokine gene expression that results in alterations in bronchiolar growth and in airway inflammatory cell number and function to induce persistent airway obstruction and hyperresponsiveness. The specific aims of the proposed research are: l) To use Northern analysis and in situ hybridization to determine whether virus-susceptible BN rats have increased cytokine gene expression of mRNA for transforming growth factor-beta1 (TGF-beta1), tumor necrosis factor-alpha (TNF-alpha), interleukin-3, and/or stem cell factor (SCF) following Sendai virus infection and prior to bronchiolar growth abnormalities and hyperresponsiveness; 2) To use Western blot analysis and lymphocyte sub-set immuno-cytochemistry to determine whether the enhanced susceptibility of BN rats to Sendai virus-induced growth abnormalities is due to less efficient antiviral immune response (CD8 lymphocytes and anti- HN antibody) than in F344 rats; 3) To characterize virus-induced alterations in bronchiolar and bronchiolar mast cell eicosanoid metabolism with high performance liquid chromatography and enzyme-linked immunoassay; and 4) To use breeding studies to determine whether resistance and susceptibility in rats to virus-induced airway abnormalities and hyperresponsiveness are inherited in a polygenic or simple Mendelian pattern. The long-term goal of this research approach will be to use simple sequence length polymorphisms and computer analysis to identify genomic segments containing loci that control susceptibility to virus- induced airway abnormalities.