FIGURE 5.

IFN-γ increases ERK activation and reduces the capacity of EGF to activate ERK but not Akt-1. a, representative Western blot of whole cell lysates of T₈₄ cells, probed for phosphorylated or total ERK. b, in IFN-γ-treated cells, densitometric analysis revealed a significant increase in ERK phosphorylation at baseline (IFN-γ versus control; *, p ≤ 0.05; n = 8). c, following EGF stimulation, increased ERK phosphorylation was detected in both groups. However, the relative increase in phosphorylation compared with time 0 revealed a reduced capacity of EGF to induce ERK activation in IFN-γ-treated cells. d, representative Western blot of whole cell lysates of T₈₄ cells, probed for phosphorylated (Ser⁴⁷³) or total Akt-1. e, the relative increase in phosphorylation over time with EGF stimulation showed no influence of prior IFN-γ treatment on EGF-induced Akt phosphorylation. f, phosphorylation of Akt-1, measured by ELISA, was significantly increased by EGF over time, but this was not influenced by the presence or absence of IFN-γ treatment (*, p ≤ 0.05 after 30 min of EGF stimulation; n = 3 in duplicate). Error bars, S.E.