The RhlR quorum-sensing receptor controls Pseudomonas aeruginosa pathogenesis and biofilm development independently of its canonical homoserine lactone autoinducer.
The RhlR quorum-sensing receptor controls Pseudomonas aeruginosa pathogenesis and biofilm development independently of its canonical homoserine lactone autoinducer.
复制标题
DOI：
10.1371/journal.ppat.1006504
复制
发表时间：
2017-07
期刊：
影响因子：
6.7
通讯作者：
Bassler BL
中科院分区：
文献类型：
--
作者：
Mukherjee S;Moustafa D;Smith CD;Goldberg JB;Bassler BL
群体感应(Quorum Sensing，QS)是细菌细胞间的一种通讯过程，依赖于细胞外信号分子自身诱导物的产生、释放和反应。QS控制人类致病菌铜绿假单胞菌的毒力和生物被膜的形成。铜绿假单胞菌具有两个典型的Luxi/R型QS系统，LASI/R和RhLI/R，分别产生和检测3OC12-高丝氨酸内酯和C4-高丝氨酸内酯。在这里，我们使用生物膜分析、报告分析、RNA-seq研究和动物感染分析来表明RhlR同时指导RhlI依赖和RhlI非依赖的调节因子。在缺乏RhlI的情况下，RhlR控制生物膜形成所需基因的表达以及编码毒力因子的基因。与这些发现一致的是，Δrh lR和Δrh lI突变体具有完全不同的生物被膜表型，Δrh lI突变体在动物中显示出完全的毒力，而Δrh lR突变体则减弱。Δ突变体的无细胞培养液含有刺激依赖于Rh1R的基因表达的活性。我们提出了一个模型，在该模型中，RhlR除了其典型的C4-高丝氨酸内酯自动诱导剂外，还对另一种配体做出反应。在没有RhlI的情况下，这种交替的配基促进RhlR依赖的转录程序。群体感应(QS)是细菌用来协调群体行为的细胞间通信过程。QS对许多细菌的毒力和生物膜的形成是必不可少的，包括人类病原体铜绿假单胞菌。铜绿假单胞菌对常用抗生素产生耐药性，是疾控中心ESKAPE病原菌名单上的优先病原菌，具有较高的临床应用价值。迫切需要新的抗菌剂来对抗铜绿假单胞菌感染，这使得针对QS的干扰成为一种有吸引力的方法。在这里，我们在生物膜条件下研究铜绿假单胞菌，这种生物膜条件模拟了真实的环境和医学背景下的铜绿假单胞菌的生活方式，而不是在传统的实验室条件下。这一策略使我们能够发现铜绿假单胞菌使用一种新的QS信号分子来控制生物膜的形成和毒力。这种新的信号分子与长期以来已知的QS受体RhlR一起发挥作用。利用生理学、遗传学和分子生物学研究，结合感染的动物模型，我们表征了QS组分在生物被膜形成和毒力中的作用。我们发现RhlR和可能的新信号分子对这两个性状都是至关重要的。我们的工作表明，以小分子抑制剂为靶点的RhlR可能为新型抗菌药的开发提供了一条令人兴奋的前进道路。
Quorum sensing (QS) is a bacterial cell-to-cell communication process that relies on the production, release, and response to extracellular signaling molecules called autoinducers. QS controls virulence and biofilm formation in the human pathogen Pseudomonas aeruginosa. P. aeruginosa possesses two canonical LuxI/R-type QS systems, LasI/R and RhlI/R, which produce and detect 3OC12-homoserine lactone and C4-homoserine lactone, respectively. Here, we use biofilm analyses, reporter assays, RNA-seq studies, and animal infection assays to show that RhlR directs both RhlI-dependent and RhlI-independent regulons. In the absence of RhlI, RhlR controls the expression of genes required for biofilm formation as well as genes encoding virulence factors. Consistent with these findings, ΔrhlR and ΔrhlI mutants have radically different biofilm phenotypes and the ΔrhlI mutant displays full virulence in animals whereas the ΔrhlR mutant is attenuated. The ΔrhlI mutant cell-free culture fluids contain an activity that stimulates RhlR-dependent gene expression. We propose a model in which RhlR responds to an alternative ligand, in addition to its canonical C4-homoserine lactone autoinducer. This alternate ligand promotes a RhlR-dependent transcriptional program in the absence of RhlI. Quorum sensing (QS) is a cell-to-cell communication process that bacteria use to coordinate group behaviors. QS is essential for virulence and biofilm formation in many bacteria including the human pathogen Pseudomonas aeruginosa. P. aeruginosa has high clinical relevance because it has acquired resistance to commonly used antibiotics, and is a priority pathogen on the CDC ESKAPE pathogen list. The urgent need for new antimicrobials to combat P. aeruginosa infections makes targeting QS for interference an attractive approach. Here, we investigate P. aeruginosa under biofilm conditions that mimic authentic P. aeruginosa lifestyles in environmental and medical contexts rather than in traditional laboratory conditions. This strategy enabled us to find that P. aeruginosa uses a novel QS signal molecule that controls biofilm formation and virulence. The new signal molecule acts together with the long-known QS receptor RhlR. Using physiologic, genetic, and molecular studies, combined with animal models of infection, we characterize the roles of QS components in biofilm formation and virulence. We find that RhlR and the putative new signal molecule are crucial for both traits. Our work suggests that targeting RhlR with small molecule inhibitors could provide an exciting path forward for the development of novel antimicrobials.
登录
查看更多内容
影响因子：
3.2
作者：
BRINT, JM;OHMAN, DE
通讯作者：
OHMAN, DE
影响因子：
3.6
作者：
Boles, BR;Thoendel, M;Singh, PK
通讯作者：
Singh, PK
影响因子：
48
作者：
Gibson, Daniel G.;Young, Lei;Smith, Hamilton O.
通讯作者：
Smith, Hamilton O.
影响因子：
4
作者：
Bhattacharjee, Arunima;Nusca, Tyler D.;Hochbaum, Allon I.
通讯作者：
Hochbaum, Allon I.
影响因子：
62.1
作者：
Churchill, Mair E. A.;Chen, Lingling
通讯作者：
Chen, Lingling