Background: To gain insight into the mechanisms responsible for tissue neutrophil immigration in sinusitis, primary nasal fibroblasts are analyzed for synthesizing and delivering neutrophil chemokines.
Methods: Primary nasal fibroblast cell culture was treated with tumor necrosis factor (TNF)-α concentrations of 20 and 200 ng/ml for 2, 8, 24 and 72 h. Chemokine concentrations in supernatants were determined by enzyme-linked immunoassay (ELISA) and chemokine mRNA expression in fibroblasts was measured by reverse transcriptase polymerase chain reaction (RT-PCR). Biological chemotactic activity was identified by three-step high-performance liquid chromatography (HPLC) and by bioassay measuring neutrophil chemotaxis in a single Boyden chamber system.
Results: Interleukin (IL)-8 and growth-related oncogene (GRO)-α were induced in nasal fibroblast culture by proinflammatory stimulus. After 24 h of stimulation neutrophil chemotactic activity only was detected for IL-8. Granulocyte chemotactic protein (GCP)-2 mRNA was already significantly up-regulated after 2 h of stimulation.
Conclusion: Induction of IL-8 protein dominates chemokine synthesis 24 and 72 h after stimulation, whereas induction of GCP-2 mRNA seems to have a role in the early phase after 2 h of exposition with TNF-α.