Pseudomonas aeruginosa quorum-sensing signal molecules induce IL-8 production by human corneal epithelial cells.
OBJECTIVE
The aim of the present study was to evaluate whether the quorum-sensing molecules of Pseudomonas aeruginosa could induce the production of interleukin-8 (IL-8) in human corneal epithelial (HCE) cells in vitro.


METHODS
A confluent monolayer of immortalized HCE cells was treated with 12.5 to 50 microM n-(3-oxododecanoyl)-L-homoserine lactone (OdDHL) or n-butanoyl-L-homoserine lactone (BHL) for 18 hours, or challenged with a wild-type P. aeruginosa PAO1 and its quorum-sensing mutants PAO-JP1 (lasI(-)), PDO100 (rhlI(-)), and PAO-JP2 (lasI(-)/rhlI(-)) for 1 hour. The levels of IL-8 in the culture supernatants were determined using an enzyme-linked immunosorbent assay.


RESULTS
OdDHL stimulated the production of IL-8 in HCE cells in a dose dependent manner. IL-8 production was seen with low concentrations of BHL (12.5 and 25 microM), but not at higher levels. There was significantly less IL-8 production in the HCE cells challenged with quorum-sensing mutants compared with the wild-type strain PAO1-challenged cells.


CONCLUSIONS
These findings suggest that quorum-sensing signal molecules OdDHL and BHL may directly contribute to the induction of the inflammatory response in Pseudomonas keratitis.
Zhu
Hua
H
Institute for Eye Research, Vision CRC and School of Optometry and Vision Science, The University of New South Wales, Sydney, NSW 2052, Australia.
Conibear
Tim C R
TC
Thuruthyil
Sophy J
SJ
Willcox
Mark D P
MD
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000494:pharmacology; D001426:Bacterial Proteins / Q000502:physiology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000378:metabolism; D006714:Homoserine / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis*; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D053038:Quorum Sensing / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
D001426:Bacterial Proteins; D016209:Interleukin-8; C109860:N-(3-oxododecanoyl)homoserine lactone; C092312:N-butyrylhomoserine lactone; D006714:Homoserine; D015107:4-Butyrolactone