The Pseudomonas aeruginosa type III translocon is required for biofilm formation at the epithelial barrier.
The Pseudomonas aeruginosa type III translocon is required for biofilm formation at the epithelial barrier.
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DOI：
10.1371/journal.ppat.1004479
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发表时间：
2014-11
期刊：
影响因子：
6.7
通讯作者：
Engel JN
中科院分区：
文献类型：
--
作者：
Tran CS;Rangel SM;Almblad H;Kierbel A;Givskov M;Tolker-Nielsen T;Hauser AR;Engel JN
铜绿假单胞菌是一种革兰氏阴性的条件致病菌，临床上常引起机体产生耐药生物膜。虽然生物膜的形成已被广泛研究，在体外玻璃或塑料表面，少得多的是已知的生物膜形成在上皮屏障。我们先前已经表明，当添加到极化上皮细胞的顶端表面时，铜绿假单胞菌在感染后60分钟内迅速形成细胞相关聚集体。通过共聚焦显微镜，我们现在表明，细胞相关的聚集体表现出生物膜的关键特征，包括细胞外基质的存在和与嗜热细菌相比对抗生素的耐药性增加。使用III型分泌系统中的同基因突变体，我们发现，translocon，而不是效应子本身，所需的极化上皮细胞的表面上的细胞相关的聚集，并在早期的时间点在小鼠模型的急性肺炎。相比之下，在非生物表面上的聚集不需要易位子，这表明在细胞相关聚集期间III型分泌系统的新功能。感染野生型细菌的上皮细胞或用成孔毒素链球菌溶血素O处理的细胞的上清液可以拯救III型分泌突变体中的聚集体形成，表明细胞相关聚集需要一种或多种宿主细胞因子。我们的研究结果表明，以前未被赞赏的功能，III型易位在形成铜绿假单胞菌生物膜在上皮屏障，并证明，生物膜可能在感染的早期时间点形成。铜绿假单胞菌是免疫功能低下患者的一种致命的革兰氏阴性机会致病菌，临床感染涉及耐药生物膜的形成。虽然铜绿假单胞菌生物膜的形成已被广泛研究的玻璃或塑料表面上，很少有人知道在上皮屏障的生物膜的形成。这项研究表明，在上皮细胞上，铜绿假单胞菌形成聚集体，表现出生物膜的关键特征。此外，我们证明，聚集在上皮细胞和小鼠肺炎的早期时间点需要孔形成介导的III型分泌系统。我们的研究结果表明，生物膜样聚集诱导的宿主细胞因子，孔形成后释放，这表明一个意想不到的作用，急性毒力因子在生物膜形成。
Clinical infections by Pseudomonas aeruginosa, a deadly Gram-negative, opportunistic pathogen of immunocompromised hosts, often involve the formation of antibiotic-resistant biofilms. Although biofilm formation has been extensively studied in vitro on glass or plastic surfaces, much less is known about biofilm formation at the epithelial barrier. We have previously shown that when added to the apical surface of polarized epithelial cells, P. aeruginosa rapidly forms cell-associated aggregates within 60 minutes of infection. By confocal microscopy we now show that cell-associated aggregates exhibit key characteristics of biofilms, including the presence of extracellular matrix and increased resistance to antibiotics compared to planktonic bacteria. Using isogenic mutants in the type III secretion system, we found that the translocon, but not the effectors themselves, were required for cell-associated aggregation on the surface of polarized epithelial cells and at early time points in a murine model of acute pneumonia. In contrast, the translocon was not required for aggregation on abiotic surfaces, suggesting a novel function for the type III secretion system during cell-associated aggregation. Supernatants from epithelial cells infected with wild-type bacteria or from cells treated with the pore-forming toxin streptolysin O could rescue aggregate formation in a type III secretion mutant, indicating that cell-associated aggregation requires one or more host cell factors. Our results suggest a previously unappreciated function for the type III translocon in the formation of P. aeruginosa biofilms at the epithelial barrier and demonstrate that biofilms may form at early time points of infection. Clinical infections by Pseudomonas aeruginosa, a deadly Gram-negative, opportunistic pathogen of immunocompromised patients, involve the formation of antibiotic-resistant biofilms. Although P. aeruginosa biofilm formation has been extensively studied on glass or plastic surfaces, less is known about biofilm formation at the epithelial barrier. This study shows that, on epithelial cells, P. aeruginosa forms aggregates that exhibit key characteristics of biofilms. Furthermore, we demonstrate that aggregation on epithelial cells and at early time points in mouse pneumonia requires pore formation mediated by the type III secretion system. Our results indicate that biofilm-like aggregation is induced by a host cell factor that is released after pore formation, suggesting an unexpected role for an acute virulence factor in biofilm formation.
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影响因子：
6.7
作者：
Bucior I;Pielage JF;Engel JN
通讯作者：
Engel JN
影响因子：
3.1
作者：
Bucior, Iwona;Mostov, Keith;Engel, Joanne N.
通讯作者：
Engel, Joanne N.
影响因子：
3.6
作者：
Allesen-Holm, M;Barken, KB;Tolker-Nielsen, T
通讯作者：
Tolker-Nielsen, T
影响因子：
3.1
作者：
Goure, J;Pastor, A;Attree, I
通讯作者：
Attree, I
MDCK细胞中IgA的受体介导的转介症是通过根尖回收的内体。
影响因子：
7.8
作者：
Apodaca, G;Katz, L A;Mostov, K E
通讯作者：
Mostov, K E