Immune modulation by Pseudomonas aeruginosa quorum-sensing signal molecules.

There is burgeoning recent interest in the potential of bacterial quorum-sensing signal molecules (QSSMs) such as the long chain N-acylhomoserine lactones (AHLs) and 4-quinolones produced by Pseudomonas aeruginosa for modulating immune function. While it is clear that QSSMs have well defined immune modulatory potential in vitro, and are detectable in body fluids (such as sputum from cystic fibrosis patients infected with P. aeruginosa) at levels which might be expected to modify immune competence, the true impact of bacterial QSSMs on host physiology in vivo has yet to be fully determined.