Collaborative Research: OSIB: Chemical signaling in a host-microbe symbiosis

尽管人们认识到共生微生物的重要性，但宿主和微生物之间使用的化学语言却知之甚少。当涉及到细菌用来适应宿主环境的表达化学时，目前的知识空白，而确定负责的化学物质将大大增加我们对细菌如何能够在生态位环境中定植和维持自己或在同一生态位上与其他微生物竞争的理解。我们的建议是高度跨学科的，正如我们的团队一样，结合前沿遗传学，尖端分析测量科学和药物化学来确定发光细菌，费氏弧菌，如何使用一种小化合物来更好地定殖它的鱿鱼宿主，同时也发现了其他尚未确定的分子。因此，我们的系统提供了一个切入点，以识别可能与其他有益和致病定植系统相关的化学信号，并在可访问的模型中阐明相关靶点。我们将与“拓展你的视野”组织合作，利用我们易于操作、环保的模型系统，在拉美裔人口众多的大蒙特雷湾地区，为5-10年级的年轻女孩创建一个实践推广讲习班。在植物、动物和人类宿主-微生物相互作用中，识别和表征宿主-微生物交流的小分子是一个重要的研究方向。短尾鱿鱼和费氏弧菌发光细菌之间的自然简单联系提供了一种共生关系，可以在原位研究中发现功能化合物。通过复杂的细菌遗传和基因组方法，可以获得宿主的细菌定植，并且可以在活体动物中对感染部位进行成像。我们的合作努力已经开发出新的方法来识别和研究这种共生关系中的小分子。这项工作导致鉴定了一种小有机分子，称为二酮哌嗪（DKP），作为费氏弧菌共生生物膜和发光表型的潜在贡献者。我们使用成像质谱法鉴定了额外的生物膜相关分子，并使用结构解析和合成化学，我们合成了大量的DKP。在这里，我们将利用我们在成像质谱，结构分离和解析，前向遗传筛选和合成生物有机化学方面的跨学科专业知识来确定该DKP的功能，并确定该分子的生物合成起源，以探索它是否用于其他微生物-宿主系统。这个模型系统将使我们能够解决目前在我们对共生细菌在宿主特定组织定植过程中产生的小分子的理解方面的知识空白。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Despite an appreciation of the importance of symbiotic microbes, the chemical language used between hosts and microorganisms is poorly understood. There is a current gap in knowledge when it comes to the expressed chemistry that bacteria utilize to adapt to host environments, and the identification of the chemical matter responsible would add significantly to our understanding of how bacteria are able to colonize and maintain themselves in niche environments or out-compete other microorganisms for the same niche. Our proposal is highly interdisciplinary, as is our team, incorporating forward genetics, cutting-edge analytical measurement science, and medicinal chemistry to identify how the glowing bacterium, Vibrio fischeri, uses a small chemical compound to better colonize its squid host while also discovering other molecules that have yet to be identified. Our system thus provides an entry point to identify chemical signals that may be relevant in other beneficial and pathogenic colonization systems and to elucidate the relevant targets in an accessible model. We will leverage our tractable, environmentally intriguing model system to create a hands-on outreach workshop with young girls in grades 5-10 in the greater Monterey Bay area, which has a high Latinx population, in collaboration with Expanding Your Horizons.There is significant interest in identifying and characterizing small molecules that underlie host-microbe communication in plant, animal, and human host-microbiome interactions. The naturally simple association between Euprymna scolopes bobtail squid and Vibrio fischeri luminescent bacteria provides a symbiotic relationship that can be interrogated in situ to discover functional compounds. Bacterial colonization of the host is accessible to sophisticated bacterial genetic and genomic approaches, and the site of infection can be imaged in live animals. Our collaborative efforts have developed novel methods to identify and study small molecules in this symbiosis. This work has resulted in the identification of a small organic molecule, termed diketopiperazine (DKP), as a potential contributor to symbiotic biofilm and luminescence phenotypes from V. fischeri. We have used imaging mass spectrometry to identify additional biofilm-associated molecules, and, using structure elucidation and synthetic chemistry, we have synthesized large amounts of the DKP. Here, we will leverage our interdisciplinary expertise in imaging mass spectrometry, structure isolation and elucidation, forward genetic screening, and synthetic bioorganic chemistry to identify the function of this DKP and identify the biosynthetic origin of this molecule to explore whether it is used in other microbial-host systems. This model system will allow us to address current knowledge gaps in our understanding of the small molecules that symbiotic bacteria produce during colonization of host specific tissues.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.