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The following is a summary of “An in vitro study of the impact of IL-17A and IL-22 on ciliogenesis in nasal polyps epithelium via the Hippo-YAP pathway,” published in the November 2024 issue of Allergy and Immunology by Qiu et al. 

Cilia loss and impaired motile ciliary functions are common in chronic rhinosinusitis with nasal polyps (CRSwNP). IL-17A and IL-22, key cytokines in type 3 inflammation, affect epithelial cell function similarly. 

Researchers conducted a retrospective study to examine the effects of IL-17A and IL-22 on ciliogenesis in nasal polyps and investigated the role of Hippo-YAP signaling in this process. 

They assessed mRNA and protein expression levels of IL-17A and IL-22 in nasal tissues from patients with CRSwNP and healthy controls. They established a primary human nasal epithelial cell model cultured for 28 days at air-liquid interface, using IL-17A and IL-22 concentrations of 2 ng/mL, 10 ng/mL, and 50 ng/mL. They also used the Hippo-YAP pathway inhibitor verteporfin to investigate the effects of IL-17A and IL-22 on ciliated cells. 

The results showed that IL-17A and IL-22 mRNA and protein levels were significantly higher in CRSwNP than in healthy controls, with a strong correlation between the 2. YAP expression was elevated in the nucleus of ciliated cells, correlating with clinical symptoms. IL-17A reduced ciliated cells and disrupted ciliogenesis, while IL-22 did not. YAP expression in ciliated cells declined during differentiation, blocked by IL-17A. Verteporfin reversed IL-17A effects by increasing ciliated cells, suppressing nuclear YAP, and enhancing ciliary beating. 

Investigators found that IL-17A and IL-22 overexpression in the nasal epithelium of CRSwNP impaired epithelial cell differentiation. IL-17A disrupted motile cilia morphogenesis through YAP activation. 

Source: sciencedirect.com/science/article/abs/pii/S0091674924007140