Pseudomonas aeruginosa eradicates Staphylococcus aureus by manipulating the host immunity
Erwan Pernet1, Laurent Guillemot2, Pierre-Régis Burgel3
11] Unité de défense innée et inflammation, Institut Pasteur, 75015 Paris, France [2] INSERM U874, 75015 Paris, France [3] Université Pierre et Marie Curie, Cellule Pasteur UPMC, rue du Dr Roux, 75015 Paris, France.
Nature Communications
|October 8, 2014
Summary
Pseudomonas aeruginosa triggers the host enzyme secretory phospholipase A2 (sPLA2-IIA) to eliminate Staphylococcus aureus in cystic fibrosis (CF) airways. This highlights how one bacterium can manipulate host immunity to eradicate another.
Area of Science:
- Host-pathogen interactions in cystic fibrosis
- Microbial ecology of the airways
- Innate immune responses to bacterial infections
Background:
- Cystic fibrosis (CF) patients experience shifts in airway bacterial colonization, from Staphylococcus aureus in youth to Pseudomonas aeruginosa in adulthood.
- The underlying mechanisms driving this transition in dominant bacterial species remain largely unknown.
- Understanding these dynamics is crucial for developing effective CF treatment strategies.
Purpose of the Study:
- To investigate the role of host-derived secretory phospholipase A2 type IIA (sPLA2-IIA) in the age-dependent shift of bacterial colonization in CF airways.
- To determine the differential effects of sPLA2-IIA on S. aureus and P. aeruginosa.
- To elucidate the mechanisms by which P. aeruginosa influences sPLA2-IIA production.
Main Methods:
- Quantification of sPLA2-IIA levels in CF patient expectorations across different age groups.
- In vitro assessment of sPLA2-IIA's bactericidal activity against S. aureus and P. aeruginosa.
- Analysis of sPLA2-IIA expression in CF bronchial epithelial cells stimulated by P. aeruginosa.
- In vivo evaluation of P. aeruginosa-induced sPLA2-IIA production in a murine lung infection model.
Main Results:
- sPLA2-IIA levels significantly increase with age in CF patient expectorations.
- sPLA2-IIA demonstrates potent bactericidal activity against S. aureus but has minimal impact on P. aeruginosa.
- P. aeruginosa actively induces sPLA2-IIA expression in CF bronchial epithelial cells and in vivo, promoting S. aureus clearance.
Conclusions:
- P. aeruginosa-induced sPLA2-IIA production contributes to the eradication of S. aureus in CF airways.
- This study reveals a novel mechanism where a pathogen manipulates host immunity to eliminate competing bacteria.
- Findings suggest sPLA2-IIA as a potential therapeutic target for modulating airway microbiota in CF.
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