Fig. 3.

STATs in the presence of MPRV/V. (a) STAT degradation. 2fTGH cells were infected with MPRV strain BeAnn 370284 at 10 m.o.i. or mock-infected. They were stimulated with 3.2×10⁴ U human IFNα ml⁻¹ at 16 h p.i. or left untreated. At 25 h p.i., the cells were harvested and the lysates were analysed by Western blot probed with monoclonal antibodies against human STAT1, STAT2, STAT3 and cellular actin, as well as with an antiserum raised against the P and V proteins of MPRV. More than 95 % of the cells were infected at the time of harvest, as determined by immunofluorescence. (b) STAT phosphorylation. 2fTGH and Vero cells were infected as above and stimulated for 20 min with 2.5×10³ U human IFN-α ml⁻¹ at 22 h p.i. or left untreated. Cells lysates were analysed by Western blot probed with antibodies against human Tyr701-phosphorylated STAT1 or Tyr689-phosphorylated STAT2.