COBRE P2: A NOVEL REGULATOR OF P AERUGINOSA VIRULENCE GENES

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 铜绿假单胞菌是一种常见的肺部病原体，可导致呼吸机相关性肺炎、慢性阻塞性肺疾病和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生物膜的形成和包括磷脂酶C(PlcH)在内的毒力因子的分泌。磷脂酰胆碱(PC)是肺表面活性物质的主要成分，也是宿主细胞膜中的主要磷脂，PLCCH的产生与上皮细胞的破坏、炎症和疾病的严重程度有关。在这里，我们集中在一个转录因子，我们确定，GbdR，控制plcH的表达响应甘氨酸甜菜碱，PC降解产物。GbdR调控超过100个基因，并在必要时调节各种毒力表型，包括在富含磷脂酰胆碱的环境中形成生物膜。我们假设GbdR协同控制plcH和其他与铜绿假单胞菌致病相关的基因的表达。我们的具体目标是(1)测试在胆碱和含PC介质中差异表达的基因的子集受GbdR控制并参与胆碱分解代谢以外的过程的假设，(2)确定GbdR结合位点并测试目标1中确定的GbdR控制的基因子集存在GbdR识别基序的假设，以及(3)测试GbdR控制的基因参与生物膜形成和毒力的假设。了解有助于生物被膜形成和毒力的途径可能为预防或治疗肺部铜绿假单胞菌提供新的方法。

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.