IL-8 production in human lung fibroblasts and epithelial cells activated by the Pseudomonas autoinducer N-3-oxododecanoyl homoserine lactone is transcriptionally regulated by NF-kappa B and activator protein-2.
The destructive pulmonary inflammation associated with Pseudomonas aeruginosa colonization is caused, in part, by the production of the chemokine IL-8, which recruits neutrophils into the lung. The Pseudomonas autoinducer, N-3-oxododecanoyl homoserine lactone (3-O-C12-HSL), is a small lipid-soluble molecule that is essential in the regulation of many P. aeruginosa virulence factors, but little is known about how it affects eukaryotic cells. In this report we demonstrate that 3-O-C12-HSL is a potent stimulator of both IL-8 mRNA and protein from human fibroblasts and epithelial cells in vitro. The IL-8 produced from these 3-O-C12-HSL-stimulated cells was found to be functionally active by inducing the chemotaxis of neutrophils. To determine a mechanism for this IL-8 induction, deletion constructs of the IL-8 promoter were examined. It was found that the DNA region between nucleotides -1481 and -546 and the transcription factor NF-kappaB were essential for the maximal induction of IL-8 by 3-O-C12-HSL. This was confirmed by EMSAs, where 3-O-C12-HSL induced a shift with both AP-2 and NF-kappaB consensus DNA. The activation of NF-kappaB and subsequent production of IL-8 were found to be regulated by a mitogen-activated protein kinase pathway. These findings support the concept that the severe lung damage that accompanies P. aeruginosa infections is caused by an exuberant neutrophil response stimulated by 3-O-C12-HSL-induced IL-8. Understanding the mechanisms of 3-O-C12-HSL activation of lung structural cells may provide a means to help control lung damage during infections with P. aeruginosa.
Smith
R S
RS
Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
Fedyk
E R
ER
Springer
T A
TA
Mukaida
N
N
Iglewski
B H
BH
Phipps
R P
RP
D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D020121:5' Untranslated Regions / Q000502:physiology; D002460:Cell Line; D002474:Cell-Free System / Q000502:physiology; D002478:Cells, Cultured; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000502:physiology*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects / Q000276:immunology; D004847:Epithelial Cells / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D005347:Fibroblasts / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D006714:Homoserine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D008168:Lung / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D016328:NF-kappa B / Q000096:biosynthesis / Q000502:physiology*; D009504:Neutrophils / Q000276:immunology; D011401:Promoter Regions, Genetic / Q000276:immunology; D011550:Pseudomonas aeruginosa / Q000472:pathogenicity / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000096:biosynthesis; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000096:biosynthesis / Q000502:physiology*; D014158:Transcription, Genetic / Q000276:immunology
D020121:5' Untranslated Regions; D004268:DNA-Binding Proteins; D016209:Interleukin-8; C109860:N-(3-oxododecanoyl)homoserine lactone; D016328:NF-kappa B; D018808:Transcription Factor AP-1; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D006714:Homoserine; D015107:4-Butyrolactone