FIG. 3.

Time course of the effect of IFN pretreatment on DV2 infection by low-passage viral isolates. HepG2 cells were exposed to DV2 (Thai strains C0477 and K0049; Nicaraguan strain N9622) at an MOI of 2 and incubated for 72 h. In each case, cells were exposed to medium or combinations of IFN-β and -γ (10 ng/ml each) as described for Fig. 2. One representative experiment of two is shown.