FIG 1.

IAV infection induces NLRP3 inflammasome-mediated IL-1β production in PAMs. (A) PAMs were infected with two SIV strains, Sk02 and Tx98, at MOIs of 0.1, 1, and 10. At 24 hpi, cell-free supernatants were harvested for porcine IL-1β ELISA, and cells were lysed for Western blotting to measure the expression of pro-IL-1β and viral proteins. ***, P < 0.001. (B) PAMs were infected with WT or UV-inactivated virus of two SIV strains at an MOI of 1 for 24 h. IL-1β production and pro-IL-1β expression were measured as described for panel A. ***, P < 0.001. (C) PAMs were treated with DMSO or an NLRP3 inhibitor, MNS, and infected with Sk02 at an MOI of 1 for 24 h. IL-1β production was measured as described for panel A. ***, P < 0.001. (D) HEK293T cells were transfected with different combinations of plasmids expressing porcine NLRP3, ASC, procaspase-1, and pro-IL-1β as indicated. At 12 hpt, the cells were mock infected or infected with Sk02 at an MOI of 5. Porcine IL-1β from the cell-free supernatants at 12 hpi was measured by ELISA. The expression of pro-IL-1β, the active caspase-1, p20, and viral proteins was measured by Western blotting in the cell lysates (***, P < 0.001). Results are representative of three independent experiments using PAMs from different piglets.