FIG 13.

Sensitivity of recombinant hMPVs to IFN-α (A) and IFN-β (B) treatment. Confluent Vero E6 cells in 24-well plates were pretreated with DMEM containing 2 or 20 U of IFN-α or IFN-β at 37°C for 4 h. Cells were then washed three times with DMEM and infected with each rhMPV mutant at an MOI of 0.5. After 1 h of adsorption, cells were washed three times with DMEM and fresh medium was added. At 48 h postinfection, supernatant from each well was harvested and the viral titers were determined by immunostaining using Vero E6 cells. Data are the averages of three experiments.