LPS-induced up-regulation of SHIP reduces, probably via inhibition of the PI3K pathway, subsequent dsRNA- or LPS-induced IFN-β mRNA levels. (A) SHIP^+/+ (□) and SHIP^−/− (■) BMmφs were pretreated with 14 μM LY, 50 nM W, or 0.1% DMSO (C) for 30 minutes before stimulation with 5 μg/mL dsRNA (top) or 10 ng/mL LPS (bottom) and 3 hours cell supernatants assessed for IFN-β by ELISA. Data are the mean plus or minus SEM of 3 independent experiments assayed in duplicate. *P < .02 compared with vehicle. In the right panels, SHIP^+/+ (□) and SHIP^−/− (■) BMmφs were pretreated with 10 μM PI3K p110 isoform-specific inhibitors 1 to 7 for 30 minutes before stimulation with 5 μg/mL dsRNA or 10 ng/mL LPS and 24 hours cell supernatants assessed for IFN-β by ELISA. Results are the mean plus or minus SEM for 3 independent experiments assayed in duplicate. *P < .05. (B) SHIP^+/+ (□) and SHIP^−/− (■) BMmφs were untreated (0) or treated with 30 nM CpG, 5 μg/mL dsRNA, or 10 ng/mL LPS for 24 hours and then stimulated with either 5 μg/mL dsRNA or 10 ng/mL LPS. Cells were harvested 3 hours after stimulation for RNA isolation and relative IFN-β mRNA levels assessed by quantitative PCR. Relative gene expression is normalized to gene expression in unstimulated cells. Results are the mean plus or minus SEM for 4 independent experiments assayed in duplicate. *P < .03 compared with untolerized cells. **P < .01 compared with untolerized cells. ***P < .002 compared with untolerized cells and SHIP^+/+ cells. ****P < .01 compared with untolerized cells but not significantly different from SHIP^+/+ cells. NS indicates not significant.