FIG. 3.

Asc-dependent IL-1β and IL-18 release by macrophages in response to L. pneumophila is inhibited by high extracellular potassium. BMMs from wild-type, Asc^−/−, Ipaf^−/−, or Casp1^−/− mice were infected with wild-type or flaA L. pneumophila at an MOI of 10. During infection, cells were cultured in the presence of an additional 50 mM KCl; control cells were incubated with an additional 50 mM NaCl. IL-1β (A), IL-18 (B), and TNF-α (C) levels in culture supernatants at 8 h postinfection were quantified by ELISA. Data are represented as averages ± standard deviations. Data are representative of four (A) or three (B and C) experiments.