Fig. 3: Virus-induced asthma exacerbation in older mice.

a Intranasal poly(I:C) 10 μg was administered to mice either for 5 days or prior to OVA sensitization/challenge as in the described protocol. b AHR to methacholine was measured on the indicated days. Some mice were treated with dexamethasone (Dex) 1 mg/kg, montelukast (Mon) 10 mg/kg, or anti-IL5 antibody (20 μg per mouse) for 3 days prior to OVA challenge. ***P < 0.001 vs. the control, ^#P < 0.05, ^###P < 0.001 between the A12 w Poly(I:C) group and drug-treated mice. c Effects of virus and drugs on total cell, neutrophil, and eosinophil counts in BALF. *P < 0.05, ***P < 0.001 between the groups; NS not significant. d Relative changes in gene expression and levels of proinflammatory cytokines in BALF. e The levels of OPN in BALF increased with viral exposure and decreased with anti-asthmatic drugs. *P < 0.05, **P < 0.01, ***P < 0.001 between the indicated groups. In an in vitro experiment, HAECs were stimulated with poly(I:C) at 1 and 10 μg/mL and treated with Dex, Mon, and anti-IL5 antibody at the indicated concentrations. f Levels of OPN in the cell culture supernatants were measured by ELISA. *P < 0.05, **P < 0.01, ***P < 0.001 between the groups. AHR airway hyperresponsiveness; Alum aluminum hydroxide; Areg amphiregulin; BALF bronchoalveolar lavage fluid; CH3L1 chitinase 3-like 1; Dex dexamethasone; Egfr epidermal growth factor receptor; Eos eosinophil; IFN-γ interferon γ; IL interleukin; Lymph lymphocyte; Macro macrophage; Mon montelukast; Neu neutrophil; OPN osteopontin; poly(I:C) polyinosinic:polycytidylic acid; Spp1 secreted phosphoprotein 1; Total total cell count; TGF-β1 transforming growth factor β1; TSLP thymic stromal lymphopoietin.