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. Method: IL-17A, IL-5, IL-6, IL-8, IL-1 beta, 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. Results: A 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. Conclusion: The 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. (C) 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.