Immature and mature moDCs have different susceptibilities to defined HCMV strains. Immature (left) and mature (right) moDCs from the same donor were infected in parallel with the same viral stocks (MOI-1) of different HCMV host cell-adapted strains: endothelial cell-propagated strains (Bob-U/E) or fibroblast-propagated strains (Bob-U/F and AD169). Twenty-four hours after infection, the immediate early-1 (IE1) viral antigen was detected in the nucleus of permeabilized, infected cells by using E13 Ab (1 experiment representative of 4).