Fig. 2.

Ganciclovir blocks cell-to-cell spread of viral proteins. Fibroblasts expressing GFP were infected with BADwt (A) or BADsubUL99 (B and C) at a multiplicity of 0.02 pfu per cell. After 24 h, the culture was treated sequentially with citrate buffer and medium containing 3% anti-HCMV Ig to inactivate residual extracellular virus, and the cells were transferred to cultures of normal fibroblasts lacking GFP in medium containing 3% anti-HCMV Ig and 100 mM ganciclovir (A and B) or in medium with no drug (C). Ten days after infection, cells were processed for immunofluorescence by using antibodies specific for the HCMV IE1 protein (blue), HCMV pp65 protein (red), or GFP (green). A Lower Right, B Lower Right, and C Lower Right display images in which the three colors are merged. (Final magnification: ×500 in A and B and ×250 in C.)