A mechanism of interleukin-25 production from airway epithelial cells induced by Japanese cedar pollen.

IL-25 likely has vital roles in initiating and activating type-2 immune responses in AR. We hypothesized that the molecules produced IL-25 by allergen-producing organisms such as JC is involved in the pathogenesis of AR. Participants included 13 patients with Japanese cedar pollinosis and 10 HCs. We measured the IL-25 protein concentration in nasal secretions and in culture supernatants of PNECs. NHBE cells were stimulated with pharmacological and immunological agents and JC. The IL-25 concentration in nasal secretions was significantly higher in patients with Japanese cedar pollinosis than in HCs. JC stimulated IL-25 production from PNECs. TNF-α, IL-4, and IL-13 significantly enhanced JC-induced IL-25 production; their activation by serine proteases was sufficient to enhance IL-25 production. Furthermore, the NADPH oxidase activity, including JC enhanced IL-25 production. A better understanding of JC-induced IL-25 production by epithelial cells may allow the development of novel therapeutic and preventive strategies for Japanese cedar pollinosis.