Chemical biology strategies for delineating the role of inter-species cell-cell communication in bacterial co-infections with Pseudomonas aeruginosa and the Burkholderia cepacia complex

项目摘要 多种微生物感染是许多肺部疾病的常见和破坏性特征，包括那些 与囊性纤维化（CF）有关。条件致病菌铜绿假单胞菌感染约50%的CF 患者，并且这些患者中的相当数量随后与这些患者的成员共同感染。 洋葱伯克霍尔德氏菌复合体（Bcc），一组17个密切相关的伯克霍尔德氏菌属物种。1，2这些物种形成 CF肺中的共生物膜，3与肺功能的快速下降相关。内在和 这些细菌在这些共生物膜内进化的抗生素抗性使得治疗选择非常有限。 最近，抗病力策略-即，使细菌无毒的疗法， 细胞过程-作为解决细菌致病性的策略， 4，5铜绿假单胞菌和伯克霍尔德氏菌都协调毒力表型 以及通过部署酰基高丝氨酸内酯（阿勒）信号用于细胞间通讯（或 群体感应（QS））。此外，与单独感染相比，它们在合并感染中似乎更具毒性， 这表明可能存在促进这种增强的物种间相互作用。QS操作 途径已经成为一种潜在的强大的抗毒力策略，并且是该领域的主要研究焦点。 我们假设QS在增强P. 铜绿：BCC合并感染。该项目的主要目标是通过以下方式来验证这一假设： 现代化学生物学、有机化学、微生物学和分子生物学的综合 生物学方法。尽管在开发用于铜绿假单胞菌的合成QS调节剂方面取得了进展， 最少的工作集中在鉴定靶向伯克霍尔德氏菌属中QS的化合物。在目标1中， 将鉴定和合成用于Bcc的QS的新型化学调节剂，证实它们修饰 毒力表型，并评估其减毒C.线虫感染这些化合物将 代表了探索QS在感染中的作用的强大工具，我们相信它们可以提供新的进入 研究QS在合并感染中的作用，例如CF肺中的合并感染。在目标2和3中，我将评估以下能力： P.铜绿假单胞菌共生物被膜共感染C.具有多种BCC成员物种的秀丽线虫。此外，我将 使用物种特异性化学工具剖析QS在这些合并感染中的作用。最后，我将挑战 用抗生素进行复合治疗的合并感染，以评估我们最好的QS调节剂是否使合并感染 或对抗生素治疗更敏感的共生物膜。实验的结果将是高度 具有影响力和新颖性，因为它们将评估QS在这两种破坏性疾病之间的合并感染中的作用 病原体的第一次，他们将进一步使用抗病力战略作为一种创新的方式， 治疗感染。

PROJECT SUMMARY Polymicrobial infections are a common and devastating feature of many lung diseases, including those associated with cystic fibrosis (CF). The opportunistic pathogen, Pseudomonas aeruginosa, infects ~50% of CF patients, and a significant number of these patients are subsequently co-infected with members of the Burkholderia cepacia complex (Bcc), a group of 17 closely-related Burkholderia species.1,2 These species form co-biofilms in the CF lung,3 which are associated with rapid decline in pulmonary function. The intrinsic and evolved antibiotic resistance of these bacteria within these co-biofilms make for very limited treatment options. Recently, antivirulence strategies—i.e., therapies that render bacteria avirulent without targeting essential cellular processes—have attracted considerable interest as a strategy to address bacterial pathogenicity without applying selective pressure.4,5 Both P. aeruginosa and Burkholderia species coordinate virulence phenotypes and biofilm production by deploying acyl homoserine lactone (AHL) signals for cell-to-cell communication (or quorum sensing (QS)). Moreover, they appear to be more virulent in co-infections as opposed to alone, suggesting that there may be interspecies interactions that facilitate this enhancement. Manipulation of QS pathways has emerged as one potentially powerful antivirulence strategy and is a primary research focus of the Blackwell lab.6-8 We hypothesize that QS plays a role in augmenting virulence in P. aeruginosa:Bcc co-infections. The broad goal of this project is to test this hypothesis through an integrated set of modern chemical biology, organic chemistry, microbiology, and molecular biology approaches. Despite the advances in developing synthetic QS modulators for P. aeruginosa, minimal work has been focused on identifying compounds that target QS in Burkholderia species. In Aim 1, I will identify and synthesize novel chemical modulators of QS for the Bcc, confirm their ability to modify virulence phenotypes, and evaluate their ability to attenuate C. elegans infections. These compounds will represent powerful tools to explore the role of QS in infection, and we believe they could provide new entry into study of the role of QS in co-infections, such as those in the CF lung. In Aims 2 and 3, I will assess the ability for P. aeruginosa to co-biofilm and co-infect C. elegans with range of Bcc member species. Furthermore, I will dissect the role of QS in these co-infections using species-specific chemical tools. Finally, I will challenge compound-treated co-infections with antibiotics, to evaluate if our best QS modulators render the co-infections or co-biofilms more susceptible to antibiotic treatment. The results of the proposed experiments will be highly impactful and novel as they will assess of the role of QS in co-infections between these two destructive pathogens for the first time, and they will further the use of antivirulence strategies as an innovative way to treat infection.