Effect of the PI3K inhibitor wortmannin on IL-5 and PAF-induced PI3K activity in human eosinophils. All samples (2 × 106 cells) were pretreated for 15 minutes at 37°C in the presence or absence of 30 nmol/L wortmannin (WTM). (A) Eosinophils were stimulated with IL-5 (10−9 mol/L) for 5 minutes at 37°C (lanes 2 and 3). Lane 1 represents PI3K activity in unstimulated eosinophils not treated with WTM and incubated at 37°C for 5 minutes. Densitometric analysis showed that the fold induction compared with the unstimulated control (lane 1) was 49.8 (lane 2) and 1.1 (lane 3). (B) Eosinophils were left untreated (lane 1, 1 minute at 37°C) or stimulated with PAF (10−6 mol/L) for 1 minute at 37°C (lanes 2 and 3). The fold induction compared with the unstimulated control (lane 1) was 24.3 (lane 2) and 1.2 (lane 3). The experiment shown is representative of three other experiments (n = 3).
