Listeria infection triggers IL-1β release and inflammasome activation in an RIG-I-dependent manner. (A) IL-1β in cell-culture supernatants of wild-type or ASC−/− Mø 18 h after infection with wt Listeria or Δhly. (B) Immunoblot of full-length (pro)caspase-1 in cell lysates or cleaved caspase 1 in the supernatant of wild-type or ASC−/− Mø 6 h after infection with wt Listeria or Δhly. (C) IL-1β in cell-culture supernatants of wild-type Mø 18 h after infection with wt, or different Listeria mutants. (D) Immunoblot of procaspase-1 in cell lysates or cleaved caspase 1 in the supernatant of wild-type Mø 6 h after infection with wt or different Listeria mutants. (E) IL-1β in cell-culture supernatants of wild-type, MDA5−/− or RIG-I−/− Mø 18 h after infection with wt, Δhly or ΔsecA2 Listeria. (F) Immunoblot of procaspase-1 and pro-IL-1β in cell lysates or cleaved caspase 1 and IL-1β in the supernatant of wild-type, MDA5−/− or RIG-I−/− Mø 6 h after infection with wt, Δhly or ΔsecA2 Listeria. (G) Like in (E) but macrophages were pretreated with 500 U/ml of IFNα or IFNβ for 2 h prior to and during infection. (H) Immunoblot 6 h after infection of procaspase-1 in cell lysates or cleaved caspase 1 in the supernatant of wild-type or RIG-I−/− Mø pretreated with IFNα or IFNβ as in (G). (I) IL-1β in cell-culture supernatants of wild-type and CARD9−/− macrophages 18 h after infection with wt Listeria, Δhly and ΔsecA2. (J) Immunoblot of wild-type, CARD9−/−, MDA5−/− or RIG-I−/− macrophages 6 h after infection with wt Listeria, Δhly and ΔsecA2. *P=0.05, **P=0.01, ***P=0.001. Figure source data can be found with the Supplementary data.