Effect of cell-free HHV-7 inoculation on primary CD4⁺ T cells evaluated at different days pi. (A) Total number of viable cells scored by Trypan blue dye exclusion. (B) The percentage of apoptosis evaluated by flow cytometry after PI staining. (C) Cell-associated HHV-7 DNA, evaluated by quantitative PCR (values are referred to 250 cells). Results of one experiment of two separate experiments performed in duplicate are shown.