Mutations in M117 facilitate MCMV replication in human cells.

(A) Schematic representation of the M117 region with the nucleotide position of each ORF in the MCMV Smith sequence (NC_004065). The positions of the h1/h2 and h3 mutations are indicated. (B) Multistep replication kinetics in human RPE-1 cells. Cells were infected with WT MCMV, the human cell-adapted MCMV/h1 and MCMV/h3 as well as the single M117 mutants MCMV-M117mut-h1 and MCMV-M117mut-h3 by using an MOI of 0.2 TCID₅₀/cell. The experiment was done in triplicate. Viral titers were determined in the supernatant and are shown as mean ±SEM. DL, detection limit.