CD39 is a negative regulator of IL-1β release and cell death. (A) wt and Cd39−/− BMMCs were primed with 1 μg/ml LPS for 3.5 h and then left untreated or stimulated with the indicated concentrations [mM] of ATP for 1 h. TCL and SN were probed for IL-1β by ELISA (n = 5). (B) Treatment as in (A); wt and Cd39−/− BMMCs were stained with Pi and analyzed by FACS (n = 6). (C) Treatment as in (A); cells were stained with FITC-conjugated Annexin V and Pi and analyzed by FACS. The morphology is displayed in the forward and side scatter (FSC/SSC); representative result (n = 4). (D) Cd39−/− BMMCs were primed with 1 μg/ml LPS for 3.5 h. The cells were then concentrated to 2*106 cells/60 μL and left untreated or stimulated with the indicated concentrations of ATP for 1 h. TCL and SN were then analyzed by immunoblotting with anti-IL-1β (top and middle panel) and anti-p85 (bottom panel, loading control). For details on indicated bands see text. (E) Treatment as in (A); SN of wt and Cd39−/− BMMCs were probed for IL-6 by ELISA (n = 6). Shown are means and SD of replicates of one representative experiment each. Statistical analysis of n independent experiments by LMM; FDR-corrected p-values: * < 0.05, ** < 0.005, and *** < 0.0005.