FIG. 3.

Dose dependence, timing, and duration of pIC antiviral effect on replication of WN virus in macrophages from both susceptible He and resistant RV mice. (A) Three different doses of pIC, 1, 10, and 100 μg/ml, were used to treat macrophages for 1 h prior to infection with WN virus. Virus titers were determined by TCID₅₀ at day 2 p.i. Average virus titers values were derived from two experiments with five replicas. Student's t test indicated significant changes for He samples for all pIC doses (0.001 < P < 0.01) and very highly significant changes for all RV samples (P ≪ 0.001). (B) One microgram of pIC per milliliter was applied 1 h or 2 days (2d) prior to infection with WN virus for 1 h. Virus titers were determined by TCID₅₀ at day 2 p.i. Average values for virus titers were derived from one experiment with two replicas. (C) One microgram of pIC per milliliter was applied 1 h prior to infection or 1 day postinfection with WN virus for 1 h. Virus titers were determined by TCID₅₀ at day 3 p.i. Average virus titer values were derived from three experiments with seven replicas indicating very significant changes for all treatments (P < 0.001; Student's t test). Standard error bars are included where appropriate. 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.