Generation of tumor necrosis factor alpha by human nasal epithelial cells and inhibition by fluticasone propionate

Accumulation of mast cells and eosinophils in the nasal epithelial layer occurs in nasal allergic reaction, However, the mechanism of accumulation of these cells has not yet been well clarified. We hypothesized that cytokines generated from the nasal epithelial cells contributed to the accumulation of these cells in the nasal epithelial layer. Recently tumor necrosis factor (TNF) was shown to promote polymorphonuclear neutrophils and eosinophils migration. And also TNF increased eosinophil binding to vascular endothelial cells. In this in vitro study we examined whether or not nasal epithelial cells can produce TNF-alpha and also whether or not glucocorticosteroid fluticasone propionate (FP) can modulate TNF-alpha production from nasal epithelial cells. Nasal epithelial cells constitutively produce TNF-alpha in accordance with the nasal epithelial cells' number and this was substantially increased in the state of nasal epithelial cell's proliferating. FP significantly reduced the level of TNF-alpha in the supernatant of cultured nasal epithelial cells for a period of 6 days. In addition, preincubation of nasal epithelial cells with FP for 6 days caused significant reduction of TNF-alpha level in the supernatant of cultured nasal epithelial cells during a further period of 6 days without FP. These data support the concept that structural cells play an active role in the control of allergic and related inflammatory processes.