Unravelling the Importance of Bacterial Signaling using Specific Interference Strategies

微生物对抗生素的耐药性正在以惊人的速度传播，创造了一种需要新的 控制微生物的策略。在这种情况下，采用干扰细菌化学物质的方法 通信(称为群体感应(QS))，有可能控制病原体而不杀死 共生和与健康相关的细菌，是非常有吸引力的。大量的细菌病原体产生和 利用酰基高丝氨酸内酯(AHL)作为化学信号分子在细胞密度依赖的情况下进行配位 方式，细菌行为，如毒力和生物被膜形成。我们的实验室已经识别、表征和 解决了细菌信号的酶猝灭剂的结构，称为内酯酶，它能降解AHLS。 使用这种群体猝灭(QQ)酶来控制病原体与使用这种酶是根本不同的 抗菌剂：这些酶没有毒性，不需要进入细胞或与受体结合，而是抑制 通过信号干扰致病。我们已经证明了它们惊人的抑制能力 体内外生物被膜形成与细菌毒力。然而，尽管付出了密集的努力来描述 信号干扰的影响，关键的机械问题仍然存在，更不用说信号在 由于缺乏工具和方法，仍然无法访问的复杂社区的背景。令人兴奋的是，我们 最近分离、生物工程和鉴定了细菌信号转导的酶猝灭剂 特殊的催化和稳定性特性，使我们能够研究QS在众多 上下文。 我们建议利用这项新技术来研究细菌中信号传递的重要性， 无论是在细胞层面还是在社区层面。我们工作的科学前提是受控和有效 信号中断将导致在细胞和社区层面上对信号的机械性理解， 包括在与疾病和/或感染有关的社区。因此，我们将(I)探讨 病原菌关键行为的信号，包括毒力和关键肺的生物被膜形成 病原体；(2)调查信号在混合群落中的重要性及其干扰对 微生物种群和(Iii)创建工具来研究关键信号分子在 在细胞和社区层面。 这项基础性研究将对社区中的信号机制提供关键的理解。 因此，它有望对田间生物学产生广泛的影响。利用新开发的工具， 它代表着在蜂窝和社区中收集全面和一致的见解的机会 微生物信号的水平。此外，本研究还将建立解决具体贡献的工具 用于信令的不同类型的AHL。

Microbial antibiotic resistance is spreading at an alarming pace, creating a situation which calls for new strategies to control microbes. In this context, approaches employing interference in the bacterial chemical communication (known as quorum sensing (QS)), that have the potential to control pathogens without killing commensal and health-associated bacteria, are extremely attractive. Numerous bacterial pathogens produce and utilize acyl homoserine lactones (AHLs) as chemical signal molecules to coordinate, in a cell density dependent manner, bacterial behaviors such as virulence and biofilm formation. Our lab has identified, characterized, and solved the structures of enzymatic quenchers of bacterial signaling, termed lactonases, which hydrolyze AHLs. The use of such Quorum Quenching (QQ) enzymes for pathogen control is fundamentally different from the use of antimicrobials: the enzymes show no toxicity, do not need to enter cells or bind to a receptor, but rather inhibit pathogenicity through signal disruption. We have demonstrated their striking ability to dramatically inhibit biofilm formation and bacterial virulence in vitro and in vivo. Yet, despite intensive efforts to characterize the effects of signal disruption, critical mechanistic questions remain, let alone the importance of signaling in the context of complex communities that remained inaccessible due to the lack of tools and methods. Excitingly, we have recently isolated, bioengineered and characterized enzymatic quenchers of bacterial signaling with exceptional catalytic and stability properties that unlock our ability to study the importance of QS in numerous contexts. We propose to take advantage of this new technology to investigate the importance of signaling in bacteria, at both the cellular and community levels. The scientific premise of our work is that controlled and effective signal disruption will lead to the mechanistic understanding of signaling at the cellular and community levels, including in communities relevant to disease and/or infection. Therefore, we will (i) explore the effects of signaling on pathogen-critical bacterial behaviors including virulence and biofilm formation for key lung pathogens; (ii) investigate the importance of signaling in mixed communities and the effect of its disruption on the microbial population and (iii) create the tools to study the specific importance of key signaling molecules at the cellular and community levels. This fundamental research will provide a critical understanding of signaling mechanisms in communities. As a result, it is expected to have broad impact on the field biology. Taking advantage of newly developed tools, it represents an opportunity to collect comprehensive and consistent insight at both the cellular and community levels of microbial signaling. Moreover, this research will establish the tools to resolve the specific contributions of the different types of AHLs used for signaling.