FIG 3.

BTV interferes with STAT1 phosphorylation. (A to C) A549 (A), HeLa (B), or Vero (C) cells were mock infected or infected with 0.01 to 0.1 TCID₅₀ of BTV-8/cell for 18 to 20 h and then left untreated (NT) or treated with IFN-α or IFN-β (1,000 IU/ml) for 30 min. (D) HeLa cells were infected with 0.05 TCID₅₀ of BTV-4/cell for 16 h and then left untreated (not treated, NT) or treated with IFN-β (1,000 IU/ml) for 30 min. For experiments shown in all panels, cells lysates were extracted and used for detection of total STAT1 and phospho-STAT1 (p-STAT1). Note the presence of double bands corresponding to the alpha form (around 91 kDa) and the beta form (around 84 kDa) of STAT1. BTV VP5 or NS3 expression was detected as a control for viral infection, and β-actin served as an internal control.