Immunomodulation of nasal epithelial cells by Staphylococcus aureus-derived serine proteases.
The impact of Staphylococcus aureus in the pathogenesis of chronic rhinosinusitis is not well understood. Therefore, we investigated primary human nasal epithelial cell cultures for their ability to produce IL-8, growth-related oncogene-alpha, and IL-6 via stimulation with trypsin and culture supernatants of different S. aureus strains and phenotypes. Inhibition of cytokine synthesis was performed using a glucocorticoid, a serine protease inhibitor, and a cysteine protease inhibitor. Finally, signal transduction pathways were analyzed by quantifying phosphorylated forms of MAPKs (PI3K, ERK, and p38) and DNA-binding assays that quantified NF-kappaB and its inhibition using BAY11-7085. In vitro studies showed that the induction of IL-8, growth-related oncogene-alpha, and IL-6 by S. aureus culture supernatants was significantly inhibited by the serine protease inhibitor. In contrast, steroids and the cysteine protease inhibitor had little effect. Activation of NF-kappaB was observed after cell treatment with trypsin and bacterial supernatants, and was inhibited by BAY11-7085 and the serine protease inhibitor. S. aureus serine proteases were identified to modulate chemokine synthesis and activate NF-kappaB in nasal epithelial cells, and may therefore be relevant for the pathophysiology of chronic rhinosinusitis.
Rudack
Claudia
C
Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital of Münster, Münster, Germany.
Sachse
Florian
F
Albert
Nils
N
Becker
Karsten
K
von Eiff
Christof
C
D002478:Cells, Cultured; D054360:Chemokine CXCL1 / Q000096:biosynthesis / Q000276:immunology; D024202:Electrophoretic Mobility Shift Assay; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells / Q000276:immunology; D006801:Humans; D056747:Immunomodulation / Q000502:physiology*; D015850:Interleukin-6 / Q000096:biosynthesis / Q000276:immunology; D016209:Interleukin-8 / Q000096:biosynthesis / Q000276:immunology; D008666:Metalloendopeptidases / Q000276:immunology*; D008875:Middle Aged; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D009297:Nasal Mucosa / Q000276:immunology*; D012220:Rhinitis / Q000276:immunology*; D057057:Serine Proteases / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D012852:Sinusitis / Q000276:immunology*; D013203:Staphylococcal Infections / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology
D054360:Chemokine CXCL1; D015850:Interleukin-6; D016209:Interleukin-8; D016328:NF-kappa B; D057057:Serine Proteases; D008666:Metalloendopeptidases; C022653:auR protein, Staphylococcus aureus