FIG 7.

Multistep growth curve of recombinant hMPVs carrying mutations in the zinc binding site. Vero E6 cells in 35-mm dishes were infected with each recombinant hMPV at an MOI of 0.01. After adsorption for 1 h, the inoculums were removed and the infected cells were washed 3 times with Opti-MEM. Then, fresh Opti-MEM containing 2% FBS was added and cells were incubated at 37°C for various time periods. Aliquots of the cell culture fluid were removed at the indicated intervals. Viral titer was determined by an immunostaining assay in Vero-E6 cells.