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

项目总结 多菌感染是许多肺部疾病的常见和破坏性特征，包括 与囊性纤维化(CF)相关。条件致病菌铜绿假单胞菌感染约50%的CF 患者，其中相当数量的患者随后与 洋葱伯克霍尔德氏菌复合体(BCC)，由17个密切相关的伯克霍尔德氏菌种组成 与肺功能迅速下降有关的CF3肺内共生物膜。内在的和 这些细菌在这些共生生物膜中进化出的抗生素耐药性使得治疗选择非常有限。 最近，抗病毒策略--即使细菌无毒而不具有靶向性的疗法-- 细胞过程-作为一种解决细菌致病性的策略引起了相当大的兴趣，而不是 施加选择性压力。4，5铜绿假单胞菌和伯克霍尔德氏菌都协调毒力表型。 通过部署用于细胞间通信的酰基高丝氨酸内酯(AHL)信号来产生生物膜(或 群体感知(QS))。此外，与单独感染相比，它们在联合感染中的毒力似乎更强， 这表明可能存在促进这种增强的物种间相互作用。QS的操控 通路已成为一种潜在的强大的抗病毒策略，也是该病毒的主要研究重点。 6-8我们假设QS在增强P。 铜绿假单胞菌：基底细胞癌合并感染。该项目的总体目标是通过以下方式来验证这一假设 集现代化学生物学、有机化学、微生物学和分子生物学于一体 生物学走近了。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针对伯克霍尔德氏菌物种中QS的化合物。在目标1中，我 将鉴定和合成用于BCC的新型QS化学调节剂，确认它们的修饰能力 毒力表型，并评估其减弱线虫感染的能力。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，例如在CF肺中的作用。在目标2和目标3中，我将评估 铜绿假单胞菌与一系列BCC成员种共被生物膜和共感染线虫。此外，我会 使用物种特定的化学工具剖析QS在这些联合感染中的作用。最后，我将挑战 使用抗生素进行复合治疗的混合感染，以评估我们最好的QS调节剂是否会导致联合感染 或联合生物膜更容易受到抗生素治疗的影响。拟议中的实验结果将是非常重要的 他们将评估QS在这两种破坏性的联合感染中的作用，这是有影响力的和新颖的 病原体的第一次，他们将进一步使用抗病毒策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.