Defining a novel small RNA associated with Pseudomonas aeruginosa infection

项目总结 了解宿主感染过程中的细菌生理对于设计有效的预防和治疗方案至关重要 治疗策略。传统上，我们对细菌致病的知识是从实验中获得的。 在标准实验室模型中进行。由于这些模型在模拟人类感染方面的局限性 细菌生理在很大程度上是由环境塑造的，这一事实与以下重要特征有关 在这些研究中，细菌的发病机制可以被忽略。在这项提案中，我们的目标是了解一种新的基因 铜绿假单胞菌在人感染过程中的表达特征PA是一个重要的致因 人类多种急性和慢性感染的病原体。通过比较转录分析， 我们最近发现了一个未鉴定的基因(PA1414)，它通常是在 人类感染。然而，目前还没有任何功能被归因于这个基因。在这里，我们提供多行 证据表明：(1)PA1414可由寄主相关的环境信号诱导，如 缺氧，进而促进PA生物膜的形成。(2)PA1414编码一种新的小RNA(SRNA)。 (3)在小鼠创伤模型中，PA1414的诱导可促进局部非传播性慢性感染。 结合PA1414仅限于Pa的分类群的事实，我们假设该sRNA 在控制PA从急性感染到慢性感染的开关方面发挥了关键作用。我们的假设将通过 提出的实验有两个具体目标。首先，我们将定义PA1414诱导对PA基因的影响 在感染期间改变其生活方式的表达。第二，我们将阐明PA1414的作用机制- 编码sRNA并发现其分子靶标。这项研究产生的信息将填补一个关键的空白 在我们对巴氏杆菌在人类感染期间的生理学的理解上。此外，考虑到PA1414是一口井- 保守的PA特异基因和编码的sRNA在人类中高度丰富，这项工作将为 为未来针对PA感染的新治疗策略的开发奠定基础。

PROJECT SUMMARY Understanding bacterial physiology during host infection is critical for designing effective prevention and treatment strategies. Traditionally our knowledge of bacterial pathogenesis has been derived from experiments conducted in standard laboratory models. Due to the limitations of these models in mimicking human infection and the fact that bacterial physiology is largely shaped by the environment, important features associated with bacterial pathogenesis can be overlooked in these studies. In this proposal, we aim to understand a novel gene expression signature of Pseudomonas aeruginosa (Pa) during human infection. Pa is a prominent causative agent of a wide variety of acute and chronic infections in humans. Through comparative transcriptomic analysis, we recently identified an uncharacterized gene (PA1414) that is often the most highly expressed Pa gene during human infection. However, no function has yet been attributed to this gene. Here we provide multiple lines of evidence demonstrating that: (1) PA1414 can be induced by host-associated environmental signals such as oxygen deprivation, which in turn promotes Pa biofilm formation. (2) PA1414 encodes a novel small RNA (sRNA). (3) induction of PA1414 promotes a localized non-disseminating chronic infection in a mouse wound model. Combined with the fact that PA1414 is restricted to the taxonomic group of Pa, we hypothesize that this sRNA is a key player in governing the acute-to-chronic infection switch in Pa. Our hypothesis will be addressed by experiments proposed in two specific aims. First, we will define how PA1414 induction impacts on Pa gene expression to alter its lifestyle during infection. Second, we will elucidate the mechanism of action of the PA1414- encoded sRNA and uncover its molecular targets. The information generated from this study will fill a critical void in our understanding of Pa physiology during human infection. In addition, considering that PA1414 is a well- conserved Pa-specific gene and the encoded sRNA is highly abundant in humans, this work will lay the foundation for future development of novel therapeutic strategies targeting Pa infection.