Critical role of interleukin-23 in development of asthma promoted by cigarette smoke.

It has been recently reported that cigarette smoke exposure during allergen sensitization facilitates the development of allergic asthma; however, the underlying mechanisms remain elusive. We evaluated the role of interleukin (IL-23) in a cigarette smoke extract (CSE)-induced Dermatophagoides pteronyssinus (Dp)-allergic asthma mouse model. BALB/c mice were exposed to CSE during allergen sensitization period. Anti-IL-23p19 or IL-23R antibody was administered during the sensitization period. And we evaluated several immunological responses. The expression of IL-23 and IL-23 receptor (IL-23R) was examined in lung tissue. IL-23 and IL-23R expression was increased in the airway epithelium of Dp/CSE co-administered mice. CSE administration during the sensitization promoted Dp-allergic sensitization and the development of asthma phenotypes. Additionally, the proportion of innate lymphoid type 2 cells (ILC2) was also increased by CSE and Dp co-instillation. Anti-IL-23 or IL-23R antibody treatment during allergen sensitization significantly diminished phenotypes of allergic asthma and the ILC2 population. The levels of IL-33 and thymic stromal lymphopoietin (TSLP) were also significantly reduced by anti-IL-23 or IL-23R antibody treatment. IL-23 may thus play a significant role in cigarette smoke-induced allergic sensitization and asthma development. Clinically, the increase in allergen sensitization due to cigarette exposure causes onset of asthma, and IL-23 may be important in this mechanism. KEY MESSAGES: IL-23 and IL-23R expression was increased in the lung epithelium of Dp and CSE co-exposed mice during sensitization period. The population of ILC2s was increased in Dp and CSE co-exposed mice during sensitization period. Anti-IL23 or IL-23R antibody treatment with co-administration of CSE and HDM during sensitization period significantly suppresses ILC2. In vitro, IL-23 blockade in Dp and CSE-stimulated epithelial cells suppressed IL-13 expression in ILC2.