OVA-induced activation of NLRP3 inflammasome and decrease of melatonin biosynthesis are TLR2 dependent. (A) NLRP3, mature IL-1β, pro-IL-1β, and caspase1(p20) western blot analysis. (B–D) Relative ratio of NLRP3 to GAPDH, IL-1β to pro-IL-1β, and caspase1(p20) to GAPDH. (E,F) ELISA analysis of IL-1β and IL-18 in BALF. (G) Western blot analysis of AANAT and ASMT in lung tissues. (H,I) Relative ratio of AANAT or ASMT to GAPDH. (J,K) The levels of 5-HT in BALF and melatonin in the lung homogenate were analyzed by ELISA. *p < 0.05, **p < 0.01, ***p < 0.001.