IL-17A as a regulator of neutrophil survival in nasal polyp disease of patients with and without cystic fibrosis

Nasal polyps in adults are characterized by a chronic inflammation of the upper airways and by the preferential activation of Th2 cells. In contrast, IL-17 producing Th17 cells dominate the inflammation in nasal polyps of cystic fibrosis (CF) patients.MethodIL-17A, IL-5, IL-6, IL-8, IL-1β, ECP, MCP-1 and myeloperoxidase expression was determined in tissue homogenates of nasal polyps of non-CF and CF patients and controls. The cellular source of IL-17A was determined by immuno-histochemistry and FACS analysis. The functional role of IL-17A in the survival of neutrophils from CF and non-CF patients was tested.ResultsA significant upregulation of IL-17A and myeloperoxidase could be observed in nasal polyps from CF-patients. The cellular sources of IL-17A in nasal polyps were mainly T-lymphocytes. IL-17A was able to modulate the survival of neutrophils in nasal polyps from non-CF patients; however the survival of neutrophils in CF patients was independent of IL-17A.ConclusionThe present study shows that IL-17A has an impact on neutrophil survival in adult nasal polyp disease, but not in nasal polyps from CF patients.