Viral-Bacterial Interactions in the Airway Epithelium

描述（由申请人提供）：众所周知，细菌感染通常会因并发病毒感染而恶化，这种情况被称为“细菌重复感染”。人类呼吸道感染的特定病毒（如流感、呼吸道合胞病毒（RSV）和副流感病毒（PIV））与细菌性病原体（如非典型流感嗜血杆菌（NTHi））有关。囊性纤维化患者的气道通常在同样的时间被铜绿假单胞菌定植，这些患者也容易感染呼吸道病毒，尽管两种病原体类型之间的关联文献较少。导致细菌超级感染的潜在机制包括：病毒诱导的先天免疫系统改变；纤毛黏液清除率降低；过量/改变的气道分泌物积聚；并且，吞噬细胞类型的活性降低。也有证据表明，病毒诱导的细菌粘附受体在上皮细胞上的上调。我们建议使用人纤毛气道上皮细胞（HAE）的体外模型，该模型在体内显示气道上皮的许多生理功能，对病毒感染对细菌重复感染的影响进行系统和定量分析。为

DESCRIPTION (provided by applicant): It is well known that bacterial infections are often made worse by concurrent viral infections, a condition known as "bacterial superinfection". Infection of the human airways by specific viruses (e.g., influenza, respiratory syncytial virus (RSV) and parainfluenza virus (PIV) have been associated with bacterial pathogens such as non-typified Haemophilus influenzae (NTHi). The airways of cystic fibrosis patients are often colonized by Pseudomonas aeruginosa at similar times that these patients are also susceptible to respiratory viruses although the association between the two pathogen-types is less well documented. Potential mechanisms proposed to result in bacterial super infection include: viral-induced alteration of innate immune systems; reduced mucociliary clearance; the accumulation of excess/altered airway secretions; and, reduced activity of phagocytotic cell-types. Evidence also exists for viral-induced up-regulation of bacterial adherence receptors on epithelial cells. We propose to use an in vitro model of human ciliated airway epithelial cells (HAE) that display many of the physiological functions of the airway epithelium in vivo to perform systematic and quantitative analyses of the effect of viral infection on bacterial superinfection. For these studies we have chosen RSV and PIV3 since we are confident that we can infect HAE with these viruses and maintain the cultures for extended periods post-inoculation. We will attempt to determine the mechanisms that are altered by these viruses that may lead to superinfection by NTHI and PA. We propose the following Specific Aims: 1) Does viral-infection of human ciliated cells promote early bacterial interactions with the airway surface microenvironment? 2) To determine the patho-physiological consequences of viral-infection of ciliated cells that result in bacterial superinfection. 3) To identify potential bacterial attachment factors that are up-regulated by viral-Infection. Elucidation of the processes/molecules that may be altered by viral infection may give insight into new therapeutic targets to limit these effects and thus reduce the pathology associated with bacterial superinfection. The novel aspect of these studies are the bringing together of methods to measure physiological and molecular changes induced by viruses in a single model system that accurately resembles the cell-type distribution of the human airway epithelium.