FIG. 6.

Prevention of viral replication in cells from susceptible He mice and human donors by various antiviral agent combinations. (A) Mouse peritoneal macrophages from susceptible He mice were treated with either IFN-α/β or pIC alone or in combination. Virus titers were monitored up to day 5 p.i. by TCID₅₀ assay. Average values for all treatments for day 2 p.i. were obtained from three experiments with six replicas, while data for the remaining time points were derived from one experiment with three replicas. (B and C) Human macrophages maintained as primary cultures were pretreated with either 10 IU of human IFN-α/β for 24 h or 1 μg of pIC/ml for 1 h prior to infection with WN virus (B), or primary macrophages obtained from another healthy donor were pretreated with 100 IU of human IFN-α/β for 24 h followed by incubation with either pIC or RPMI medium for 1 h prior to infection with WN virus (C). Virus titers were determined by TCID₅₀ at various times p.i. Average values for human macrophages were obtained from single experiments with two replicas each. The type and number of pretreatments on human macrophages were affected by the limited availability of human cells. A dashed line denotes a threshold value of 2.0 log₁₀ TCID₅₀ units for accurate detection of virus titers, while virus present below the threshold value was detected as described in the legend for Fig. 1A.