Bpur, a critical regulator of Borrelia burgdorferi infectivity

 描述(申请人提供)：所有生物体，从细菌到人类，都需要“识别”它们所在的位置，并做出相应的反应。病原体必须感觉到它在感染周期中的位置，然后产生该位置所需的因子，同时抑制不适当因子的合成。因此，关键调控通路的破坏可以抑制病原体的感染能力，这表明开发新的抗生素是有用的靶点。在对莱姆病细菌伯氏疏螺旋体的研究中，我们发现哺乳动物感染需要一种新的DNA/RNA结合蛋白BpuR的调控。伯氏杆菌调节BpuR的产生，在哺乳动物感染过程中以低水平合成，在媒介蜱的定植过程中以高水平合成。我们通过基因工程使伯氏杆菌在小鼠感染期间结构性地产生高水平的BpuR，并发现突变体在其定植小鼠的能力方面显著受损。转录分析(RNA-Seq)表明，BpuR显著影响了大约5%的伯氏杆菌操纵子的表达，干扰了几个已知毒力因子和代谢酶的细胞水平。我们假设，破坏控制BpuR生产的过程将显著抑制伯氏杆菌感染。计划中的研究旨在阐明伯氏杆菌控制这一关键调控因子表达的机制，并确定破坏这一机制对感染过程的影响。

 DESCRIPTION (provided by applicant): All organisms, from bacteria to humans, need to "recognize" where they are, and respond accordingly. A pathogen must sense its location in the infectious cycle, then produce factors necessary for that site while repressing synthesis of inappropriate factors. Thus, disruption of key regulatory pathways can inhibit a pathogen's ability to infect, indicating useful targets for developing novel antibiotics. In our studies of th Lyme disease bacterium, Borrelia burgdorferi, we discovered that regulation of a new DNA/RNA-binding protein named BpuR is required for mammalian infection. B. burgdorferi regulates production of BpuR, synthesizing it at low levels during mammalian infection processes, and at high levels during colonization of vector ticks. We genetically engineered B. burgdorferi to constitutively produce high levels of BpuR during murine infection, and found the mutant to be significantly impaired in its ability to colonize mice. Transcriptomic analyses (RNA-Seq) demonstrated that BpuR significantly affects expression of approximately 5% of B. burgdorferi operons, disturbing cellular levels of several known virulence factors and metabolic enzymes. We hypothesize that disruption of the processes controlling production of BpuR will significantly inhibit B. burgdorferi infection. The planned studies are designed to elucidate the mechanism by which B. burgdorferi controls expression of this critical regulatory factor, and determine how disrupting that mechanism impacts upon infection processes.