Surfactant protein A promotes the interaction of Pseudomonas aeruginosa with the airway epithelial cells and enhances the inflammatory response
Abstract number: O236
Barbier M., García-Sureda L., Albertí S.
Background: The association of surfactant protein A with P. aeruginosa enhances uptake by alveolar macrophages and modulates inflammatory responses including cytokine production and the oxidant burst. However, the role of this association in the interaction with the airway epithelial cells is poorly investigated.
Objective: The aim of this study was to characterise the role of surfactant protein A in the interaction of P. aeruginosa with the airway epithelial cells and its biological significance in the pulmonary pathogenesis of this microorganism.
Methods: Surfactant protein A was purified by affinity chromatography from human bronchoalveolar lavage. Binding of purified surfactant protein A to of 22 genetic unrelated P. aeruginosa isolates (11 from chronic infections and 11 from acute infections) was analysed by ELISA and Western blot analysis using specific monoclonal anti-surfactant protein A antibody.
To investigate the role of surfactant protein A in the interaction of P. aeruginosa with the airway epithelial cells, standard adhesion and invasion assays were performed using 16HBE14- bronchoepithelial cells and A549 pneumocyte type II cells incubated with P. aeruginosa pre-opsonised with surfactant protein A either in the presence of calcium or EDTA.
The production of IL-8, TNF-alfa and IL-6 by airway epithelial cells was determined by ELISA according to the manufacturer's instructions.
Results: Binding of purified surfactant protein A varied widely among P. aeruginosa clinical isolates. However, the isolates from acute infections bound surfactant protein A more efficiently than those from chronic infections. Surfactant protein A opsonisation of P. aeruginosa in the presence of calcium enhanced dramatically bacterial attachment and internalisation by both bronchoepithelial cells and pneumocytes type II. This interaction facilitated the airway epithelial cells mediated inflammatory response increasing the synthesis of IL-8, TNF-alfa and IL-6.
Conclusions: Surfactant protein A promotes the interaction of P. aeruginosa with the airway epithelial cells and enhances the production of IL-8, TNF-alfa and IL-6 by these cells. This mechanism is more effective with the isolates from acute infections than from chronic infections.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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