Figure 4

RIG-I agonist induced IL-1β secretion in dependent on NLRP3, caspase-1 and caspase-8. (A) PMA-primed THP-1 cells were transfected with siRIG-I (100 nM) or scrambled siRNA for 48 h prior to infection. Then the transfected cells were treated with RIG-I agonist 5’ppp-dsRNA for 12 h. The expression levels of RIG-I and β-actin were determined by Western blot. ELISA was applied to quantify the secreted IL-1β protein. (B) NLRP3 KD THP-1 cells were treated with 200 nM PMA for 48 h. Then the PMA-primed THP-1 cells were treated with 5’ppp-dsRNA for 12 h. The expression levels of NLRP3 and β-actin were determined by Western blot. The secreted IL-1β levels were determined by ELISA. (C) PMA-primed THP-1 cells were transfected with 5’ppp-dsRNA and then treated with Ac-YVAD-cmk or Z-IETD-FMK. The secreted IL-1β levels in the supernatant were determined by ELISA. (D) PMA-primed THP-1 cells were transfected with siNLRP3 or scrambled siRNA for 48 h prior to infection. The transfected cells were infected with EV-A71 and then treated with Ac-YVAD-cmk or Z-IETD-FMK. Supernatants were harvested at 12 h post-infection, and the secreted IL-1β levels were examined by ELISA. Data are expressed as mean value \(\pm\) SD (***p < 0.001, Student’s unpaired T-test).