The PI3-Kinase/mTOR-Targeting Drug NVP-BEZ235 Inhibits Growth and IgE-Dependent Activation of Human Mast Cells and Basophils
Figure 7
Effects of NVP-BEZ235 on mediator secretion in human MC.
A: IgE-preloaded cultured cord blood-derived MC (left panel) and IgE-preloaded lung MC (right panel) were incubated in control medium, various concentrations of NVP-BEZ235 (as indicated), LY294002 (20 µM), or wortmannin (1 µM) (30 minutes, 37°C). Then, cells were challenged with anti-IgE (10 µg/ml) at 37°C for 30 minutes. After incubation, histamine release was determined. Results show the percentage of released histamine and represent the mean±S.D. of four (cultured MC, left panel) or five independent experiments (5 lung MC samples, right panel). Asterisk (*): p<0.05. B: Cultured MC were incubated in the presence of control medium (indicated by black bars) or medium containing NVP-BEZ235, 10 µM (open bars) for 30 minutes at 37°C. Then, cells were incubated with various concentrations of anti-IgE as indicated. After incubation, supernatants and lysates were harvested and examined for histamine content. Histamine release was calculated as percent of total histamine. Results show the percent of released histamine and are expressed as mean±S.D. of three independent experiments. Asterisk (*): p<0.05. C: MC preloaded with NIP(5)-BSA-specific IgE were cultured in control medium (Co) or in various concentrations of NVP-BEZ235 (0.001–10 µM) for 30 minutes at 37°C. Thereafter, cells were washed and incubated with NIP(5)-BSA (100 ng/ml) for 90 minutes (37°C). Then, cell-free supernatants were collected and β-hexosaminidase release was measured. Results are expressed in percent of response induced by anti-IgE without NVP-BEZ235 and represent the mean±S.D of three independent experiments. Asterisk (*) indicates p<0.05.