COBRE P2: A NOVEL REGULATOR OF P AERUGINOSA VIRULENCE GENES

这个子项目是许多利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 铜绿假单胞菌是一种常见的肺部病原体，可引起呼吸机相关性肺炎、慢性阻塞性肺病和与囊性纤维化相关的肺部感染。铜绿假单胞菌的毒力可部分归因于其耐药性生物膜的形成和包括磷脂酶C（PlcH）的毒力因子的分泌。PlcH降解磷脂酰胆碱（PC），肺表面活性物质的主要成分和主要的磷脂在宿主的膜，和PlcH的生产与上皮破坏，炎症和疾病的严重程度。在这里，我们专注于一个转录因子，我们确定，GbdR，控制响应甘氨酸甜菜碱，PC降解产物的表达plcH。GbdR调节超过一百个基因，并且是多种毒力表型所必需的，包括在富含磷脂酰胆碱的环境中的生物膜形成。我们假设GbdR协同控制plcH以及与铜绿假单胞菌发病机制相关的其他基因的表达。我们的具体目的是（1）检验在胆碱和含PC培养基中差异表达的基因的子集受GbdR控制并且参与胆碱catalysis以外的过程的假设，（2）鉴定GbdR结合位点并且检验GbdR识别基序存在于Aim 1中鉴定的GbdR控制的基因的子集中的假设，以及（3）验证GbdR控制基因参与生物膜形成和毒力的假设。有助于生物被膜形成和毒力的途径的知识可以提供对预防或治疗肺中铜绿假单胞菌的新方法的深入了解。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Pseudomonas aeruginosa is a common lung pathogen that causes ventilator-associated pneumonia, chronic obstructive pulmonary disease, and lung infections associated with Cystic Fibrosis. P. aeruginosa virulence can be attributed in part to its formation of antibiotic-resistant biofilms and secretion of virulence factors including phospholipase C (PlcH). PlcH degrades phosphatidylcholine (PC), the main component of lung surfactant and the predominant phospholipid in the membranes of host, and PlcH production is associated with epithelial destruction, inflammation, and disease severity. Here, we focus on a transcription factor that we identified, GbdR, that controls the expression of plcH in response to glycine betaine, a PC degradation product. GbdR regulates over one hundred genes and in necessary for a variety of virulence phenotypes including biofilm formation in phosphatidylcholine-rich environments. We hypothesize that GbdR coordinately controls expression of plcH as well as other genes relevant to P. aeruginosa pathogenesis. Our specific aims are (1) to test the hypothesis that a subset of the genes that are differentially expressed in choline and PC-containing media are controlled by GbdR and are involved in processes other than choline catabolism, (2) to identify the GbdR binding site and to test the hypothesis that the GbdR-recognition motif is present in a subset of the GbdR-controlled genes identified in Aim 1, and (3) to test the hypothesis that GbdR-controlled genes participate in biofilm formation and virulence. Knowledge of pathways that contribute to biofilm formation and virulence may provide insight into novel ways to prevent or treat P. aeruginosa in the lung.