ROLE OF INTERLEUKIN 8 IN AIRWAY EPITHELIUM

白细胞介素 8 在气道上皮中的作用

• 批准号: 6241677
• 负责人: Jay Nadel
• 金额: $ 34.31万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6241677
• 关键词: Pseudomonas aeruginosa; bronchial mucus; corticosteroids; cystic fibrosis; dogs; enzyme linked immunosorbent assay; gene expression; human tissue; interleukin 8; messenger RNA; neutralizing antibody; neutrophil; northern blottings; protein purification; respiratory disorder; respiratory epithelium; respiratory infections

The airway epithelium exists at the interface with the external environment, so epithelial cells are strategically positioned to respond to environmental irritants (e.g., bacteria, viruses, pollutants, cigarette smoke). Neutrophil products are implicated in various inflammatory responses in airways, and work supported by Project D-3 has recently shown that neutrophil proteases are potent gland secretagogues. Airway cells (including epithelial cells) produce a cytokine, interleukin-8 (IL-8), which is a potent neutrophil chemoattractant. Studies supported by Project D-3 have provided evidence that IL-8 exists in high concentrations in sputum of patients with cystic fibrosis (CF), bronchiectasis, chronic bronchitis, and in subsets of patients with asthma, suggesting that IL-8 induction by airway cells is implicated in neutrophil recruitment. This project will utilize molecular, cellular, biochemical and physiologic tools to study the role of airway epithelial cell IL-8 in airway inflammatory responses. Because patients with CF often become infected with Pseudomonas aeruginosa (PA) bacteria, and because recent studies in Project D-3 showed that a product from PA induces IL-8 expression and secretion, studies are proposed to examine PA induction of IL-8 in epithelial and other cells in airways. Studies in humans will utilize tissue obtained from donors and recipients of lung transplants. Studies in humans must be limited, so the investigators in Project D-3 have recently cloned dog IL-8. The first goal in the project will be to express dog recombinant IL-8, to purify the recombinant protein, and to verify its activity. Antibodies to dog IL-8 will be raised, and neutralizing antibodies will be selected. Using these materials, an ELISA for dog IL-8 will be developed, so IL-8 activity can be measured. A second goal is to determine which cells in airways express IL-8 in response to PA supernatant delivered into the airways in dogs in vivo and in vitro. When neutralizing antibodies are available, its inhibitory effect on neutrophil recruitment and on airway secretion following PA supernatant will be examined. Evaluation of potential mechanisms for inhibiting IL-8 (e.g., corticosteroids) will be evaluated. The isolation, structural analysis and synthesis of the product of Pseudomonas aeruginosa bacteria that is responsible for IL-8 production in airway epithelial cells will be undertaken, in collaboration with expert bioorganic chemists in the area of carbohydrate and protein chemistry of microbes. In the future, studies will focus on other bacteria, viruses and pollutants on IL-8 production in airways. The studies have important pathophysiologic and therapeutic implications: they suggest mechanisms that underlie chronic inflammation and airway hypersecretion in diseases of airways. In CF and bronchiectasis, they suggest methods of intervention. In asthma, they suggest mechanisms that might explain the mucous plugging that is reported in pathologic studies of patients dying of asthma. In chronic bronchitis, they may provide mechanisms to explain some of the symptoms and inflammatory effects in the airways.

气道上皮存在于与外界的界面处 环境，因此上皮细胞处于战略位置以做出反应 环境刺激物（例如细菌、病毒、污染物、 香烟烟雾）。 中性粒细胞产物涉及多种 气道炎症反应，以及项目 D-3 支持的工作 最近表明，中性粒细胞蛋白酶是有效的腺体促分泌剂。 气道细胞（包括上皮细胞）产生细胞因子， 白介素 8 (IL-8)，是一种有效的中性粒细胞化学引诱剂。 D-3 项目支持的研究提供了 IL-8 存在的证据 囊性纤维化 (CF) 患者的痰液中浓度很高， 支气管扩张、慢性支气管炎以及患有以下疾病的患者亚群 哮喘，表明气道细胞诱导 IL-8 与哮喘有关 中性粒细胞募集。 该项目将利用分子、细胞、 研究气道上皮作用的生化和生理工具 细胞IL-8在气道炎症反应中的作用。 因为CF患者 经常感染铜绿假单胞菌 (PA) 细菌，并且 因为最近 D-3 项目的研究表明 PA 的一种产品 诱导 IL-8 表达和分泌，建议进行研究以检查 PA 诱导气道上皮细胞和其他细胞中的 IL-8。 研究 在人类中将利用从肺捐赠者和接受者获得的组织 移植。 对人类的研究肯定是有限的，因此研究人员 D-3 项目最近克隆了狗 IL-8。 项目的第一个目标 将表达狗重组IL-8，纯化重组体 蛋白质，并验证其活性。 狗 IL-8 抗体将 产生，并选择中和抗体。 使用这些 材料，将开发狗 IL-8 的 ELISA，因此 IL-8 活性可以 被测量。 第二个目标是确定气道中的哪些细胞 表达IL-8以响应PA上清液输送到气道中 狗体内和体外。当中和抗体可用时， 它对中性粒细胞募集和气道分泌的抑制作用 将检查以下 PA 上清液。 潜力评估 将评估抑制 IL-8（例如皮质类固醇）的机制。 产物的分离、结构分析与合成 铜绿假单胞菌负责产生 IL-8 将与以下机构合作，在气道上皮细胞中进行 碳水化合物和蛋白质领域的生物有机化学专家 微生物化学。 未来的研究将集中在其他方面 细菌、病毒和污染物对呼吸道中 IL-8 产生的影响。 这 研究具有重要的病理生理学和治疗意义： 他们提出了慢性炎症和气道的潜在机制 气道疾病中的分泌过多。 在 CF 和支气管扩张中，它们 建议干预方法。 在哮喘中，他们提出了以下机制： 可能解释病理研究中报告的粘液堵塞 死于哮喘的患者。 在慢性支气管炎中，它们可能提供 解释某些症状和炎症效应的机制 航空公司。