REGULATION OF PSEUDOMONAS INDUCED LUNG INFLAMMATION

肺部炎症在感染后的发生和持续机制尚不完全清楚。促炎性细胞因子、趋化因子和粘附分子也有作用，肺泡巨噬细胞和呼吸道上皮细胞也产生它们，但它们的相对重要性可能因宿主和感染的性质而异。在囊性纤维化（CF）患者中，肺部炎症通常在婴儿早期发生，然后进展，特别是在获得铜绿假单胞菌感染后。目前尚不清楚P. aeruginosa表达缺陷如何导致强烈和进行性的肺部炎症反应以及难治性铜绿假单胞菌感染的易感性。这种缺乏了解的同时，也缺乏关于呼吸道上皮在一般肺部炎症调节中所起作用的信息。这反映了迄今为止缺乏一种选择性和稳健的方法来测试呼吸上皮的贡献。类似地，基于相关的人类数据和一些啮齿动物模型的结果，已经提出了TNF在响应于铜绿假单胞菌感染的肺部炎症和CF中的重要作用，但是后面的研究产生了矛盾的结果。该建议解决了TNF与呼吸道上皮协同作用以调节肺部炎症和对铜绿假单胞菌的先天免疫的一般假设，并且异常调节导致CF中的过度肺部炎症。目的1）探讨肿瘤坏死因子受体缺陷小鼠对铜绿假单胞菌早期肺炎症反应增强的机制。假设：铜绿假单胞菌急性气溶胶感染后中性粒细胞募集和细菌清除的选择性早期增加将是由于肺实质细胞的炎症反应改变;这将至少部分反映这些细胞对响应铜绿假单胞菌的炎症信号进行识别的微生物模式识别受体的表达改变。目的2）通过选择性阻断NF-κ B活化并以细胞自主方式阻断小鼠气道上皮细胞，探讨气道上皮细胞在铜绿假单胞菌致肺炎症反应中的作用。假设：气道上皮细胞在铜绿假单胞菌引起的急性肺部炎症中起重要作用。目的3）确定CFTR敲除小鼠的肺中肺部炎症增加的程度，如果是这样，这是否是肺固有的并且部分归因于气道上皮中NF-κ B的异常激活。假设：CFTR KO小鼠将具有过度的肺部炎症。这将反映肺的内在过程，并且将至少部分地平行于和依赖于气道上皮中的NF-κ B活化。

The mechanisms by which lung inflammation is initiated and perpetuated in response to infection are incompletely understood. Pro-inflammatory cytokines, chemokines and adhesion molecules contribute, as do alveolar macrophages and respiratory epithelial cells which produce them, but their relative importance may differ depending on the host and the nature of the infection. In patients with cystic fibrosis (CF), lung inflammation commonly develops in early infancy and then progresses, particularly following acquisition of infection with Pseudomonas aeruginosa. How the defect in CHR expression results in the intense and progressive lung inflammatory response and predisposition to refractory infection with P. aeruginosa is unclear. This lack of understanding parallels a paucity of information regarding the role which the respiratory epithelium plays in the regulation of lung inflammation in general. This reflects the absence heretofore of a selective and robust approach by which to test the contribution of the respiratory epithelium. Similarly, an important role for TNF in lung inflammation in response to infection with P. aeruginosa and in CF has been proposed based on correlative human data and results in some rodent models, but the latter studies have yielded contradictory results. This proposal addresses the general hypothesis that TNF acts in concert with the respiratory epithelium to regulate lung inflammation and innate immunity to Pseudomonas aeruginosa, and that aberrant regulation leads to excess lung inflammation in CF. Aim 1) Explore the basis for the increased early lung inflammatory response to P. aeruginosa in TNF receptor-deficient mice. Hypothesis: The selective early increase in neutrophil recruitment and bacterial clearance following acute aerosol infection with P. aeruginosa will be due to an altered inflammatory response by lung parenchymal cells; this will reflect, at least in part, altered expression by these cells of microbial pattern recognition receptors that transduce inflammatory signals in response to P. aeruginosa. Aim 2) Explore the role of the airway epithelium in the pulmonary inflammatory response to P. aeruginosa using mice in which NF-kappaB activation is blocked selectively and in a cell-autonomous fashion in the airway epithelium. Hypothesis: The airway epithelium will play an important role in initiating acute lung inflammation in response to P. aeruginosa. Aim 3) Determine the degree to which lung inflammation is increased in the lungs of CFTR knockout mice, and if so, if this is intrinsic to the lung and due in part to aberrant activation of NF-kappaB in the airway epithelium. Hypothesis: CFTR KO mice will have excessive lung inflammation. This will reflect a process intrinsic to the lung and will parallel and be dependent, at least in part, on NF-kappaB activation in the airway epithelium.