Role of Interleukin-17A in the Eosinophil Accumulation and Mucosal Remodeling in Chronic Rhinosinusitis with Nasal Polyps Associated with Asthma

Abstract

Background: Interleukin (IL)-17A is a highly inflammatory cytokine with a robust effect on stromal cells in many tissues. Although IL-17A is known to be associated with inflammatory lung disorders by triggering an accumulation of neutrophils, the effect of IL-17A on the upper airway is still uncertain. The expression of IL-17A and its role were investigated in the nasal polyps of chronic rhinosinusitis associated with asthma. Methods: IL-17A was detected by immunohistochemistry and quantitative real-time RT-PCR. The cellular source of IL-17A was examined by double staining with EG2, CD4 and neutrophil elastase. The tissue remodeling of the nasal polyps was evaluated by assessing the epithelial damage and basement membrane thickness. Results: Both the immunoreactivity and mRNA of IL-17A were significantly detected in the nasal polyps in comparison with control normal sinus mucosa. The localization of IL-17A expression predominantly coincided with eosinophils and CD4-positive lymphocytes. Furthermore, the number of IL-17A-positive cells correlated with tissue eosinophils, but not with neutrophils. The degree of epithelial damage and basement membrane thickness was dependent on the number of infiltrated IL-17A-positive cells. Conclusion: The present study suggests, for the first time, that IL-17A plays an important role in the eosinophil accumulation in the nasal polyps and the remodeling of the nasal polyps of chronic rhinosinusitis associated with asthma.

A Retrospective Analysis of γδ T Cell Expression in Chronic Rhinosinusitis and Its Association with Recurrence of Nasal Polyps

“…γδ T cells, like innate cells, are also involved in early immune responses, producing proinflammatory cytokines (INF-γ, IL-17, TNF-α), and activate adaptive immune cells [46]. The expression of IL-17 has been reported to be increased in the nasal mucosa of CRSwNP patients and is closely related to the infiltration of eosinophils and neutrophils [47,48,49]. Recently, Xia et al [50] reported that IL-17A plays a crucial role in stimulating the production of MUC5AC and goblet cell hyperplasia through the act1-mediated signalling pathway in CRSwNP patients in China.…”

Total and Antigen- (Fungi, Mites and Staphylococcal Enterotoxins) Specific IgEs in Nasal Polyps Is Related to Local Eosinophilic Inflammation

“…A recent study indicated that both Th17 cells and IL-17 promote IgE production and exert direct proallergic effects at the level of B cells [24]. IL-17 expression was associated with allergic diseases, such as asthma [25] and CRSwNP comorbid with asthma [26]. Here, we showed that both the serum and local total IgE levels were significantly increased in AFRS, while only local total IgE, but not serum IgE, was increased in ECRS.…”

Mediators and Cytokines in Persistent Allergic Rhinitis and Nonallergic Rhinitis with Eosinophilia Syndrome

“…Not only Th17 cells can be the source of IL-17 as neutrophils, eosinophils, plasma cells and serous glands have also been identified [32,33]. A recent study by Saitoh et al [34] detected IL-17 in the nasal polyps of patients with asthma and, besides CD4 T cells, could clearly determine eosinophils as the major source of IL-17. Moreover, the authors found correlations between IL-17-positive cells and the eosinophil recruitment into the polyps, epithelial damage and the thickness of the basal membrane.…”