Fig 11. Pyroptosis triggered in ZIKV-infected monocytes were dependent on the NLRP3 inflammasome activation.

(A) Knockdown of NLRP3 in THP-1 cells. Cell lysates were prepared from lentiviral vector-transduced THP-1 cell lines, expressing shRNA1, 2, or 3 targeting mRNA of NLRP3, for western blot analyses with an NLRP3 antibody to examine the knockdown (KD) efficacy. (B) Inhibition of pro-caspase-1 and GSDMD processing in NLRP3 KD cells. Both NLRP3 or scramble shRNA KD cells were infected with ZIKV and cell lysates, prepared at various time points p.i., were subjected to western blot analyses with antibodies for pro-caspase-1, cleaved caspase-1 and GSDMD. (C) Cell viability was assessed in NLRP3 or scramble shRNA KD THP-1 infected with or without ZIKV at various MOIs by an MTT assay. (D) Culture medium was sampled at various time points p.i. from NLRP3 or scramble shRNA KD cells, infected with or without ZIKV, for measurement of secreted IL-1β by ELISA. The experiments were performed in triplicates and the data were shown as mean+SD and analysed by unpaired Students t-test. **, P<0.01; ***, P<0.001. ns, no significance.