FIG. 5.

Macrophages deficient in both Ipaf and Asc fail to activate caspase-1 in response to L. pneumophila. BMMs from wild-type (WT), Asc^−/−, Ipaf^−/−, Ipaf^−/− Asc^−/−, or Casp1^−/− mice were infected with the indicated L. pneumophila variants at an MOI of 10. (A and B) IL-1β (A) and IL-18 (B) levels in culture supernatants at 8 h postinfection were quantified by ELISA. Data are represented as averages ± standard deviations. (C) Immunoblot of the p10 fragment of caspase-1 from combined supernatants and pellets of BMMs obtained at 4 h postinfection. Data are representative of four (A and C) or two (B) experiments. ND, measurable quantities not detected.