(A) DHX33 expression was analyzed by real-time PCR (left) and immunoblotting (IB) (right) in THP-1 cells that were naïve and expressing either scrambled shRNA (sh-scramble) or shRNA specific for DHX33 (sh-DHX33-1, sh-DHX33-2). GAPDH served as a loading control.
(B) NLRP3, ASC and caspase-1 expression was analyzed by IB in THP-1 macrophages expressing sh-scramble or shRNA specific for NLRP3 (sh-NLRP3), ASC (sh-ASC), caspase-1 (sh-caspase-1) or DHX33.
(C-F) THP-1 macrophages expressing shRNA were stimulated for 8 h with 5 μg/ml poly I:C delivered to the cytosol via Lipofectamine 2000 (Lipo) (C and D) or with 2 μM nigericin (E and F). Culture supernatants were analyzed for IL-18 and IL-β by ELISA (C and E) and for cleaved caspase-1 by IB (D and F). Cell lysates were analyzed by IB for pro-caspase-1 and GAPDH (D and F).
(G and H) IL-18 secretion was measured by ELISA in culture supernatants of THP-1 macrophages stimulated for 8 h with 5 μg/ml R848 (G) or with 5 μg/ml poly dA:dT plus Lipo (H).
Graph shows the mean ± SD of triplicate wells (**P<0.001 versus scramble). Data are representative of three independent experiments. See also Figure S1.