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Automated, High-Throughput Detection of Bacterial Adherence to Host Cells
07:21

Automated, High-Throughput Detection of Bacterial Adherence to Host Cells

Published on: September 17, 2021

The Pseudomonas aeruginosa exopolysaccharide Psl facilitates surface adherence and NF-kappaB activation in A549 cells

Matthew S Byrd1, Bing Pang, Meenu Mishra

  • 1Department of Microbiology and Immunology, Wake Forest University Health Sciences, Winston-Salem, North Carolina, USA.

Mbio
|August 31, 2010
PubMed

Insights

The Pseudomonas aeruginosa biofilm polysaccharide Psl enhances airway infections by increasing bacterial contact with epithelial cells, thereby boosting flagellin-mediated inflammatory signaling. This study reveals Psl

Area of Science:

  • Microbiology and Immunology
  • Bacterial Pathogenesis
  • Cellular and Molecular Biology

Background:

  • Pseudomonas aeruginosa is an opportunistic pathogen causing airway infections through interactions with host epithelial cells and mucus.
  • The biofilm polysaccharide Psl is known to mediate initial bacterial attachment but its role in pathogenesis remains unclear.
  • Flagellin, a component of P. aeruginosa, is a known activator of proinflammatory signaling pathways.

Purpose of the Study:

  • To investigate the contribution of the Psl polysaccharide to P. aeruginosa adherence to epithelial cells.
  • To determine the impact of Psl on flagellin-mediated proinflammatory signaling.
  • To elucidate the mechanisms by which Psl influences host-pathogen interactions in airway infections.

Main Methods:

  • Utilized an NF-kappaB luciferase reporter system in the human A549 epithelial cell line.
  • Assessed bacterial adherence using scanning electron microscopy (SEM) with Psl and flagellin mutants.
  • Investigated Psl-dependent structures involved in bacterial adherence.

Main Results:

  • Both Psl and flagellin are essential for the full activation of NF-kappaB and the production of interleukin-8 (IL-8) chemokine.
  • Psl does not directly activate NF-kappaB but enhances flagellin-mediated signaling by increasing bacterial-epithelial cell contact.
  • SEM confirmed differential adherence of Psl/flagellin mutants and identified Psl-dependent membrane structures potentially involved in adherence.

Conclusions:

  • Psl plays a critical role in P. aeruginosa airway infections by promoting bacterial adherence and facilitating flagellin-induced inflammatory responses.
  • The study refutes the hypothesis that Psl protects against host recognition, instead highlighting its positive role in initiating inflammatory signaling.
  • Understanding Psl's function in enhancing bacterial-epithelial cell interactions is crucial for developing targeted anti-pseudomonal therapies.

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