IL-3 induces a PI3-kinase–independent antiapoptotic pathway in basophils. (A,B) Basophils were stimulated or not with IL-3 (50 ng/mL) for 24 hours in the absence (Control) or presence of different inhibitors: PI3-kinase inhibitors, LY2940002 (LY, 30 μM), and wortmannin (WT, 100 nM); mTOR inhibitor, rapamycin (Rap, 50 μM). Inhibitors were added 30 minutes before the addition of IL-3. (A) The percentage of apoptotic (annexin V–positive) cells is shown. Data are from 5 independent experiments and reported as the mean plus SEM. *P < .05 for comparison of the treatment with medium control. ns indicates not significant for comparison of WT versus LY in medium. †P < .05, WT versus LY in the presence of IL-3, by 1-way ANOVA. (B) Procaspase 3, activated caspase 3, granzyme B (GzB), and Pim1 as well as phosphorylation of Stat5 were analyzed by Western blotting using specific antibodies.