The murine model of allergic airway inflammation was established according to previous study (27). Briefly, the mice (6–8 weeks old) were sensitized on day 0 with an intra-peritoneal injection of OVA (Sigma, St. Louis, MO, USA) emulsified with 1 mg potassium aluminum sulfate (Sangon Biotech, Shanghai, China) in 500 μl of saline. Airway inflammation was induced by inhalation of 1% aerosolized OVA 30 min per day, for consecutive 7 days. Control mice received saline-sensitization and inhalation of nebulized saline solution. The mice from WT-OVA-Melatonin group were administered with melatonin (10 mg/kg, Sigma), and the mice from TLR2−/−-OVA-Luzindole group were administered with luzindole (30 mg/kg, Sigma) 1 h before allergen-challenge through intra-peritoneal injection, respectively, the dose of melatonin and luzindole was used according to previous studies (19, 28). Experiments were performed with six mice per group. Mice were harvested 24 h following the last challenge.