FIG. 4.
Effect of pretreatment with IFN-γ on the induction of DNA binding of STAT1 by LPS. (A) Pattern of activated STAT1 binding to the pIRE by IFN-γ. (B) Where indicated, cells were treated with IFN-γ (50 U/ml) for 2 h prior to LPS treatment for 30 min. The LPS concentrations were 100 (lanes 1 and 4), 10 (lane 6), and 1 (lane 8) ng/ml. Nuclear extracts were analyzed by EMSA using a 32P-labeled pIRE probe for STAT1 binding. Only the relevant region of the blot is shown.