Abstract
In many model systems, cystic fibrosis (CF) phenotype airway epithelial cells in culture respond to P. aeruginosa with greater interleukin (IL)-8 and IL-6 secretion than matched controls. In order to test whether this excess inflammatory response results from the reported increased adherence of P. aeruginosa to the CF cells, we compared the inflammatory response of matched pairs of CF and non CF airway epithelial cell lines to the binding of GFP-PAO1, a strain of pseudomonas labeled with green fluorescent protein. There was no clear relation between GFP-PAO1 binding and cytokine production in response to PAO1. Treatment with exogenous aGM1 resulted in greater GFP-PAO1 binding to the normal phenotype compared to CF phenotype cells, but cytokine production remained greater from the CF cell lines. When cells were treated with neuraminidase, PAO1 adherence was equalized between CF and nonCF phenotype cell lines, but IL-8 production in response to inflammatory stimuli was still greater in CF phenotype cells. The polarized cell lines 16HBEo-Sense (normal phenotype) and Antisense (CF phenotype) cells were used to test the effect of disrupting tight junctions, which allows access of PAO1 to basolateral binding sites in both cell lines. IL-8 production increased from CF, but not normal, cells. These data indicate that increased bacterial binding to CF phenotype cells cannot by itself account for excess cytokine production in CF airway epithelial cells, encourage investigation of alternative hypotheses, and signal caution for therapeutic strategies proposed for CF that include disruption of tight junctions in the face of pseudomonas infection.
Highlights
Chronic infection of the lung with Pseudomonas aeruginosa and the inflammatory response it stimulates cause much of the morbidity and most the mortality in cystic fibrosis (CF) patients
Binding of Green fluorescent protein (GFP)-PAO1 to the cell lines Our prior data indicate that for both the 16HBEo- AS and S cell pairs, and for the 9HTEo- pCEP and pCEP-R cell pairs, IL-8 and IL-6 production increased with addition of increasing amounts of PAO1 over the range of 107 to 109 organisms [6]
Binding of GFP-PAO1 was similar in untreated 16HBEo- sense (S) and antisense (AS) cell lines, at all concentrations, and in untreated 9HTEo-pCEP and pCEP-R cell lines, at all concentrations (Figure 1)
Summary
Chronic infection of the lung with Pseudomonas aeruginosa and the inflammatory response it stimulates cause much of the morbidity and most the mortality in CF patients. But not all, model systems, CF airway epithelial cells respond to P. aeruginosa or its products with increased IL-8 and/or IL-6 production compared to non-CF cells [4,6,7,8,9,10,11]. In some, but not all, model systems binding of P. aeruginosa to CF airway epithelial cells is in excess of its binding to non-CF cells [1216]. Taken together, these data have been interpreted to mean that the excess cytokine responses in CF epithelium are due to increased stimulus applied at the cell surface by elevated bacterial adherence in the CF phenotype cells [15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
