title: Contribution of the proinflammatory cytokine IL-18 in the formation of human nasal polyps.
abstract: Nasal polyposis is a chronic inflammatory disease of the nasal mucosa. The etiology and the mechanisms of formation of nasal polyps are still not clear. Interleukin (IL)-18 is a novel proinflammatory cytokine that plays important roles in regulating immune inflammatory responses. However, the presence of IL-18 in human nasal mucosa and its roles in the inflammatory process of nasal polyps has not been studied yet. In this study, it was the first time to investigate the expression of IL-18 in human nasal mucosa and nasal polyps, and its potential function in the formation of nasal polyps. Surgical samples were analyzed by Western blot and immunohistochemistry to evaluate the expression and location of IL-18, and its correlated cytokines, IL-4, and IFN-γ. Furthermore, the airway epithelial cell line, A549, was used to investigate the mutual regulation of IFN-γ, IL-4, and IL-18. IFN-γ, IL-4, and IL-18 were all highly expressed in the epithelial cells, submucosal glands, and infiltrating inflammatory cells in the nasal polyp tissues, comparing with the control samples. Especially, the expression of IL-18 was upregulated significantly in nasal polyp tissues compared with control tissues. In addition, IL-18 was expressed in A549 cells in response to lipopolysaccharide and IL-4. Our data suggest that nasal epithelial cells are involved in the pathogenesis of nasal polyps formation and potentially via the secretion of IL-18, which is likely to play important roles in the formation of nasal polyps.
authors.affiliation: Department of Immunology, Basic Medical College, Tianjin Medical University, Tianjin, People's Republic of China.
authors.forename: Guimin
authors.initials: G
authors.lastname: Zhang
authors.forename: Xiang
authors.initials: X
authors.lastname: Jing
authors.forename: Xinting
authors.initials: X
authors.lastname: Wang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Shi
authors.forename: Peiyong
authors.initials: P
authors.lastname: Sun
authors.forename: Chao
authors.initials: C
authors.lastname: Su
authors.forename: Mengyu
authors.initials: M
authors.lastname: Zhu
authors.forename: Zhenxia
authors.initials: Z
authors.lastname: Yang
authors.forename: Zhi
authors.initials: Z
authors.lastname: Yao
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002460:Cell Line; D006801:Humans; D018836:Inflammation Mediators / Q000502:physiology*; D020382:Interleukin-18 / Q000502:physiology*; D008875:Middle Aged; D009297:Nasal Mucosa / Q000378:metabolism / Q000473:pathology*; D009298:Nasal Polyps / Q000378:metabolism* / Q000473:pathology; D020545:Respiratory Mucosa / Q000378:metabolism / Q000473:pathology; D055815:Young Adult
chemical_list: D018836:Inflammation Mediators; D020382:Interleukin-18