Figure 4.

Effects of wortmannin or MEK inhibitor, PD 098059, on FcɛRI-mediated TNF-α production in MC/9 cells. (A and B) MC/9 cells sensitized with anti-OVA IgE (1 × 10⁶ per ml) were incubated with 1 nM to 1 μM wortmannin for 15 min (A) or 30 μM PD 098059 for 1 h (B). DMSO at 0.01% or 0.1% was used as a control vehicle. The cells were then incubated with 10 μg/ml OVA for 3 h. TNF-α in the medium was measured by ELISA. Wortmannin at 1 nM to 1 μM inhibited antigen-induced TNF-α production in a dose-dependent manner (mean ± SD, n = 4; ∗∗, P < 0.01). At 30 μM PD 098059 did not affect TNF-α production (mean ± SD, n = 4; NS, not significant). (C) MC/9 cells sensitized with anti-OVA IgE (3 × 10⁶ per ml) were incubated with 3–30 μM PD 098059 or 0.1% DMSO (control and 0 nM) for 1 h. The cells were then incubated with 10 μg/ml OVA or PBS (control) for 5 min. ERK2 activities were measured as described in the text. MBP, myelin basic protein. A representative autoradiograph from three independent experiments is shown.