Analysis of quorum-signaling crosstalk within the squid-vibrio symbiosis

说明(申请人提供)：有益微生物对包括人类在内的真核生物的整体健康是必不可少的。为了探索有益微生物慢性感染宿主上皮组织的基本原理，我一直在研究海洋细菌费氏弧菌和夏威夷鱿鱼Euprymna scolope之间的互惠共生。特别是，我重点研究了费氏弧菌的LuxU-Luxo信号系统，该信号系统在弧菌科的所有成员中都是保守的，包括霍乱弧菌和创伤弧菌等病原体。虽然这个信号系统调节致病弧菌的毒力因子，但我目前的研究表明，LuxU-Luxo信号对费氏弧菌与鱿鱼建立共生关系也很重要。最近，我发现多个传感器蛋白与LuxU-Luxo调节通路相互作用，这表明一个复杂的信号网络控制着参与细菌定植的基因的表达。在这里，我建议研究这种形式的信号串扰，因为它在本质上起作用。具体地说，我计划使用遗传学和生物化学方法系统地描述LUX和传感器蛋白之间的相互作用。我还将确定哪些感受器蛋白在宿主中是活跃的，并确定它们相应的调节蛋白。最后，我将确定LuxU-Luxo系统的信号是否对宿主粘液分泌产生影响，宿主粘液分泌在费氏弧菌成功定植鱿鱼后终止。这个K99奖项将使我能够在Edward Ruby博士和Margaret McFall-Ngai博士的指导下完成我的博士后培训，因此我可能会启动一个全面的跨学科研究计划，作为一家主要研究机构的独立研究员来研究宿主和微生物的相互作用。 与公共健康相关：细菌必须整合多个信号输入，以协调适合其环境的反应。研究有益微生物在其自然宿主生态位中的细胞信号将揭示宿主与微生物相互作用的基本原理，并有助于我们理解微生物对我们健康的作用。

DESCRIPTION (provided by applicant): Beneficial microbes are essential for the overall health of eukaryotic organisms, including humans. To explore the fundamental principles underlying chronic infections of host epithelial tissue by beneficial microbes, I have been studying the mutualistic symbiosis between the marine bacterium Vibrio fischeri and the Hawaiian squid Euprymna scolopes. In particular, I have focused on characterizing the LuxU-LuxO signaling system of V. fischeri, which is conserved in all members of the Vibrionaceae, including pathogens such as V. cholerae and V. vulnificus. While this signaling system regulates virulence factors in pathogenic vibrios, my current research shows that LuxU-LuxO signaling is also important for V. fischeri to establish the symbiosis with squid. Recently, I have discovered that multiple sensor proteins interact with the LuxU-LuxO regulatory pathway, suggesting that a complex signaling network controls the expression of genes involved in bacterial colonization. Here, I propose to examine this form of signaling crosstalk as it functions in nature. Specifically, I plan to systematically characterize the interactions between LuxU and the sensor proteins using both genetic and biochemical approaches. I will also identify which sensor proteins are active in the host and determine their corresponding regulons. Finally, I will determine whether signaling by the LuxU-LuxO system has an impact on host mucus secretion, which terminates after V. fischeri successfully colonizes the squid. This K99 award will enable me to complete my postdoctoral training under the mentorships of Drs. Edward Ruby and Margaret McFall-Ngai, so I may launch a comprehensive interdisciplinary research program to study host-microbe interactions as an independent investigator at a major research institution. PUBLIC HEALTH RELEVANCE: Bacteria must integrate multiple signaling inputs to coordinate responses appropriate to their environments. Examining cell signaling in a beneficial microbe within its natural host niche will uncover the fundamental principles of host-microbe interactions and contribute to our understanding of the roles microbes have on our health.