The Pseudomonas quinolone signal (PQS) stimulates chemotaxis of polymorphonuclear neutrophils.

Abstract

Cross-talk between bacteria and mammalian cells is increasingly recognized as an important factor, especially during chronic infections. In particular, the interaction of extracellular bacterial signaling molecules with cells of the innate immune response is of special interest. In this context, we investigated whether the Pseudomonas quinolone signal (PQS) which is a quorum sensing molecule produced by bacteria and participates in biofilm formation and virulence has any influence on polymorphonuclear neutrophils (PMN), the cells of the "first line defense" against bacterial infections. We found that PQS did not enhance the bactericidal activity of PMN and did not induce apoptosis at concentrations up to 100 µM. However, PQS stimulated chemotaxis of PMN in doses of 10-100 µM. This PQS-dependent chemotaxis could be inhibited with SB203580 which blocks MAPkinase p38, suggesting a signaling pathway similar to AHL-12 induction. Using bacterial cell culture supernantants of Pseudomonas aeruginosa wild-type cells and a PQS-deficient mutant strain support the in vivo relevance of these findings. Since PQS is produced in the early phase of biofilm formation, PMN infiltration could be timely enough to eradicate bacteria before biofilm formation is completed, which confers the bacteria with a relative resistance to host defense mechanisms.

• Authors: Gertrud M Hänsch, Birgit Prior, Gerald Brenner-Weiss, Ursula Obst, Joerg Overhage
• Journal: Journal of applied biomaterials & functional materials (J Appl Biomater Funct Mater) Vol. 12 Issue 1 Pg. 21-6 (Jun 12 2014) ISSN: 2280-8000 [Electronic] United States
• PMID: 24829042 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Enzyme Inhibitors
• Imidazoles
• Pyridines
• Quinolones
• p38 Mitogen-Activated Protein Kinases
• SB 203580

Topics

• Biofilms
• Chemotaxis (drug effects, immunology)
• Enzyme Inhibitors (pharmacology)
• Humans
• Imidazoles
• Neutrophils (immunology, pathology)
• Pseudomonas aeruginosa (physiology)
• Pyridines
• Quinolones (immunology)
• p38 Mitogen-Activated Protein Kinases (antagonists & inhibitors, immunology)