Fig. 4.

DPPC does not inhibit nigericin- or LLME-induced release of IL-1β. A: DPPC was added to LPS-primed U937 cells together with nigericin. IL-1β levels were measured 30 min after application of nigericin in cell culture supernatants. Nicotine was included as a known inhibitor of BzATP-dependent IL-1β release. B, C: Human PBMCs were isolated from healthy human donors, left untreated (B) or pulsed with LPS (C), cultured for 3 h and stimulated with nigericin or LLME in the presence or absence of DPPC. IL-1β levels were measured 30 min thereafter in cell culture supernatants. Apyrase was included (A–C) to hydrolyze ATP that might have been released by U937 cells. A Kruskal-Wallis test was followed by Mann-Whitney rank-sum test; data are presented as individual data points; bars represent median; whiskers represent percentiles 25 and 75.