Liver injury, STAT1 and SOCS1 activation are attenuated, whereas STAT3 activation is slightly enhanced in Con A–induced hepatitis in IFN-γ^–/– mice. (a) IFN-γ^+/+ mice and IFN-γ^–/– mice were injected with 15 μg/g of Con A. At various time points, total liver protein extracts and RNA were prepared and analyzed by Western blotting and RT-PCR (indicated by asterisks), respectively, using Ab’s and primers as indicated. Induction of pSTAT1, pSTAT3, IRF-1, Bcl-X_L, SOCS1, and SOCS3 was quantified by PhosphorImager analysis (left panel), as described in Methods. The values are shown as means ± SEM from three independent experiments at each time point. *P < 0.001, ^#P < 0.01, and ^§P < 0.05 vs. corresponding Con A–treated wild-type control groups at the same time point. (b) Serum ALT levels from these mice were measured. Values shown as means ± SEM from three mice at each time point. (c) Photomicrographs of representative mouse livers from 9-hour Con A–treated mice with H&E staining are shown (original magnification ×200 and ×400). White arrows indicate massive necrosis observed in the liver.