Polymicrobial Interactions in the Lung

铜绿假单胞菌是一种条件致病菌，是慢性呼吸道感染的重要致病菌 阻塞性肺疾病（COPD），社区获得性肺炎（CAP），呼吸机相关性 肺炎（VAP）、非CF支气管扩张和囊性纤维化（CF）。最近的研究表明，病毒和P。 铜绿假单胞菌感染的肺部是协同的，并显着有助于发病率和死亡率 与COPD、CF、CAP、VAP和非CF支气管扩张相关。我研究的长期目标是 阐明铜绿假单胞菌和呼吸道病毒协同作用的细胞和分子机制， 导致肺部疾病。我的短期研究目标是阐明铜绿假单胞菌 感染干扰宿主清除呼吸道病毒。铜绿假单胞菌分泌一种名为Cif（CFTR）的蛋白质 抑制因子，最初因其抑制CFTR介导的气道细胞Cl分泌的能力而命名）， 其由PA 2934（或cif）基因编码。Cif是由实验室和临床分离的P. 铜绿假单胞菌通过下调CFTR Cl分泌和粘膜纤毛分泌来抑制宿主免疫应答。 间隙此外，Cif降低了TAP 1（抗原加工相关转运蛋白）的丰度， 我最近的初步研究表明，它抑制了I类MHC对甲型流感病毒抗原的呈递， 分子和细胞毒性T淋巴细胞（CTL）清除病毒感染的能力。我的初步数据也 表明宿主响应病毒病原体释放的细胞因子，即干扰素-α， 铜绿假单胞菌分泌Cif。关于分泌的细菌蛋白如何抑制 宿主对病毒病原体的免疫应答，并且很少有数据阐明宿主免疫应答是如何产生的。 反应改变了细菌毒素从微生物病原体的释放。因此，我将在体外使用 生物化学、高分辨率成像和体内免疫学技术，以检测以下四种特异性 目的：（1）检验Cif减少抗原呈递和CTL介导的免疫应答的假说。 （2）检验Cif减少流感病毒抗原呈递和CTL介导的流感病毒抗原结合的假设。 （3）通过以下方法检验铜绿假单胞菌和RSV共感染对每种病原体有益的假设： 减少RSV的病毒抗原呈递和CTL清除并促进铜绿假单胞菌定殖;以及 (4)检验宿主免疫应答增加铜绿假单胞菌毒力因子分泌的假设。我 预计这些研究将阐明铜绿假单胞菌如何降低肺清除病毒的能力， 感染，并最终确定新的治疗方法，以控制合并铜绿假单胞菌和 呼吸道病毒感染

Pseudomonas aeruginosa is an opportunistic pathogen and an important pathogen in patients with chronic obstructive pulmonary disorder (COPD), community acquired pneumonia (CAP), ventilator-associated pneumonia (VAP), non-CF bronchiectasis and cystic fibrosis (CF). Recent studies suggest that viral and P. aeruginosa infections of the lung are synergistic and dramatically contribute to the morbidity and mortality associated with COPD, CF, CAP, VAP, and non-CF bronchiectasis. The long-term goal of my research is to elucidate the cellular and molecular mechanisms whereby P. aeruginosa and respiratory viruses synergize to cause lung disease. My short-term research goal is to elucidate the mechanism whereby P. aeruginosa infection interferes with host clearance of respiratory virus. P. aeruginosa secretes a protein called Cif (CFTR Inhibitory Factor, originally named because of its ability to inhibit CFTR-mediated Cl secretion by airway cells), which is coded by the PA2934 (or cif) gene. Cif, which is secreted by laboratory and clinical isolates of P. aeruginosa, inhibits the host immune response by down-regulating CFTR Cl secretion and mucociliary clearance. In addition, Cif reduces the abundance of TAP1 (Transporter Associated with Antigen Processing), which my recent preliminary studies reveal, suppresses influenza A virus antigen presentation by class I MHC molecules and the ability of cytotoxic T lymphocytes (CTL) to clear viral infections. My preliminary data also demonstrate that cytokines, namely interferon-γ, released by the host in response to viral pathogens, increase the secretion of Cif from P. aeruginosa. Very little is known about how secreted bacterial proteins suppress the host immune response to viral pathogens, and there is minimal data elucidating how the host immune response alters the release of bacterial toxins from microbial pathogens. Accordingly, I will use in vitro biochemical, high resolution imaging, and in vivo immunological techniques to test the following four specific aims in this proposal: (1) Test the hypothesis that Cif reduces antigen presentation and CTL-mediated clearance; (2) Test the hypothesis that Cif reduces influenza virus antigen presentation and CTL-mediated clearance; (3) Test the hypothesis that P. aeruginosa and RSV co-infection benefits each pathogen by reducing viral antigen presentation and CTL-clearance of RSV and promoting P. aeruginosa colonization; and (4) Test the hypothesis that the host immune response increases virulence factor secretion by P. aeruginosa. I anticipate that these studies will elucidate how P. aeruginosa reduces the ability of the lung to clear viral infections and, ultimately, identify new therapeutic approaches to control combined P. aeruginosa and respiratory virus infections.