The Pseudomonas aeruginosa Exopolysaccharide Psl Facilitates Surface Adherence and NF-κB Activation in A549 Cells
The Pseudomonas aeruginosa Exopolysaccharide Psl Facilitates Surface Adherence and NF-κB Activation in A549 Cells
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DOI：
10.1128/mbio.00140-10
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发表时间：
2010-07-01
期刊：
影响因子：
6.4
通讯作者：
Wozniak, Daniel J.
中科院分区：
文献类型：
--
作者：
Byrd, Matthew S.;Pang, Bing;Wozniak, Daniel J.
为了使机会性革兰氏阴性病原体铜绿假单胞菌引起气道感染，病原体与上皮细胞和上覆的粘膜层相互作用。我们研究了生物膜多糖Psl对上皮细胞粘附的贡献以及Psl对鞭毛蛋白的促炎信号传导的影响。Psl与铜绿假单胞菌对生物和非生物表面的初始附着有关，但其在发病机制中的直接作用尚未评估（L.妈，K. D.杰克逊河M. Landry，M. R. Parsek和D. J. Wozniak，J. Bacteriol. 188：8213-8221，2006）。在人上皮细胞系A549中使用NF-κ B荧光素酶报告系统，我们表明Psl和鞭毛蛋白对于NF-κ B的完全激活和白细胞介素8（IL-8）趋化因子的产生是必需的。我们证明Psl不直接刺激NF-κ B活性，但间接地作为增加细菌细胞和上皮细胞之间的接触的结果，它促进鞭毛蛋白介导的促炎信号传导。我们确认差分粘附的PSL和/或鞭毛蛋白突变体的扫描电子显微镜，并确定PSL依赖的膜结构，可能参与粘附。虽然我们假设Psl会保护铜绿假单胞菌不被上皮细胞系A549识别，但我们反而观察到Psl在鞭毛蛋白介导的NF-κ B活化中的积极作用，这可能是细菌细胞和上皮细胞之间接触增加的结果。铜绿假单胞菌还可引起严重肺炎、烧伤伤口感染和败血症，使其对人类健康的总体影响显著。铜绿假单胞菌对宿主组织的附着，通常导致寄生生物膜感染，以及鞭毛蛋白诱导的炎症都是重要的毒力机制。我们探索了生物膜多糖Psl在铜绿假单胞菌发病机制中的作用，发现Psl是A549上皮细胞表面粘附所需的，并且作为粘附素，它促进鞭毛蛋白介导的NF-κ B活化。这项工作是为了更好地了解感染的初始事件，并揭示了生物膜多糖以一种新的方式促进炎症。
In order for the opportunistic Gram-negative pathogen Pseudomonas aeruginosa to cause an airway infection, the pathogen interacts with epithelial cells and the overlying mucous layer. We examined the contribution of the biofilm polysaccharide Psl to epithelial cell adherence and the impact of Psl on proinflammatory signaling by flagellin. Psl has been implicated in the initial attachment of P. aeruginosa to biotic and abiotic surfaces, but its direct role in pathogenesis has not been evaluated (L. Ma, K. D. Jackson, R. M. Landry, M. R. Parsek, and D. J. Wozniak, J. Bacteriol. 188: 8213-8221, 2006). Using an NF-kappa B luciferase reporter system in the human epithelial cell line A549, we show that both Psl and flagellin are necessary for full activation of NF-kappa B and production of the interleukin 8 (IL-8) chemokine. We demonstrate that Psl does not directly stimulate NF-kappa B activity, but indirectly as a result of increasing contact between bacterial cells and epithelial cells, it facilitates flagellin-mediated proinflammatory signaling. We confirm differential adherence of Psl and/or flagellin mutants by scanning electron microscopy and identify Psl-dependent membrane structures that may participate in adherence. Although we hypothesized that Psl would protect P. aeruginosa from recognition by the epithelial cell line A549, we instead observed a positive role for Psl in flagellin-mediated NF-kappa B activation, likely as a result of increasing contact between bacterial cells and epithelial cells.IMPORTANCE Pseudomonas aeruginosa is the predominant airway pathogen causing morbidity and mortality in individuals affected by the genetic disease cystic fibrosis. P. aeruginosa can also cause severe pneumonia, burn wound infections, and sepsis, making its overall impact on human health significant. The attachment of P. aeruginosa to host tissues, often leading to recalcitrant biofilm infections, and inflammation induced by flagellin are both important mechanisms of virulence. We explored the role of the biofilm polysaccharide Psl in the pathogenesis of P. aeruginosa and found that Psl is required for surface adherence to A549 epithelial cells, and as an adhesin, it facilitates flagellin-mediated NF-kappa B activation. This work was done to better understand the initial events of infection and revealed that a biofilm polysaccharide contributes to inflammation in a novel manner.