Pseudomonas aeruginasa LPS: A Post-Genomic Analysis

描述(由申请人提供)：这项研究的长期目标是了解脂多糖(LPS)在铜绿假单胞菌毒力中的作用，以便开发新的疗法和疫苗来对抗这种重要的病原体。铜绿假单胞菌脂多糖的O抗原部分在急性感染中是毒力所必需的，它的缺失对囊性纤维化患者的慢性肺部感染至关重要。亲本实验旨在确定从O11血清组PAl03菌株合成O抗原的途径，确定该O抗原基因座的转录组织，并在两种不同的小鼠感染模型中测试O抗原突变。这项探索性拨款的目的是了解铜绿假单胞菌0抗原是如何调节的。已被证明显著影响铜绿假单胞菌0抗原表达的条件之一是温度；在45摄氏度时，不表达O抗原。我们将分析RNA和蛋白质产物，以确定O抗原是转录调控还是转录后调控。利用遗传方法，我们将确定O抗原调节因子。我们将突变这个温度调节因子，并使用包括微阵列和蛋白质组分析在内的后基因组技术来识别受O抗原调控的其他基因和蛋白质。揭示这一调控的本质将使我们能够提出抑制O抗原表达的机制，从而降低这种细菌在急性感染中的毒力。通过这笔赠款获得的结果，与父提案中描述的突变分析和毒力研究相结合，可能有助于开发针对这种重要的机会性病原体的新策略。

DESCRIPTION (provided by the applicant): The long-term goal of this research is to understand the role of lipopolysaccharide (LPS) in the virulence of Pseudomonas aeruginosa in order to develop novel therapeutics and vaccines to combat this important pathogen. The O antigen portion of P. aeruginosa LPS is required for virulence in acute infections and its loss is critical for chronic lung infections in cystic fibrosis patients. The experiments in the parent grant are directed at defining the pathway of synthesis of the O antigen from the serogroup O11 strain PAl03, determining the transcriptional organization of this O antigen locus, and testing O antigen mutants in two different mouse models of infection. The goal of this exploratory grant is to understand how P. aeruginosa 0 antigen is regulated. One of the conditions that has been shown to dramatically effect the expression of P. aeruginosa 0 antigen is temperature; at 45 degrees C, no O antigen is expressed. We will analyze RNA and protein products to determine whether O antigen is transcriptionally or post-transcriptionally regulated. Using genetic approaches, we will identify the O antigen regulator. We will mutate this temperature regulator and use post-genomic techniques including micro-array and proteomic analyses to identify additional genes and proteins that are regulated with O antigen. Uncovering the nature of this regulation will allow us to propose mechanisms to inhibit O antigen expression and thereby decrease the virulence of this bacterium in acute infections. Results obtained through this grant, in combination with the mutational analysis and virulence studies described in the parent proposal, may be beneficial in the development of new strategies that target this important opportunistic pathogen.