Figure 3.

Vpr packaged into an empty virion is sufficient to induce apoptosis. (a) 5 × 10³ infected HeLa cells were analyzed by annexin V staining at 24, 48, and 72 h postinfection. DNA analysis at 48 h postinfection revealed that 27.7%, 31.0%, 80.6%, 95.9%, 27.7%, and 85.9% of mock-, HR’Thy(Vpr−)-, HR’Thy(Vpr+)-, HR’Vpr-, RNA-(Vpr−)- and RNA-(Vpr+)-infected cells, respectively, were in the G₂ phase of the cell cycle, indicating the presence of 1.6 × 10⁴ to 4.8 × 10⁴ infectious units per infection. Results are for mock (⧫)-, HR’Thy(Vpr−) (■)-, HR’Thy(Vpr+) (▴)-, HR’Vpr (×)-, RNA-(Vpr−) (□)-, and RNA-(Vpr+) (●)-infected cells. The data shown are representative of four independent experiments. (b) The percent of dead cells in the cultures was determined at the same time as the cells were analyzed for annexin V staining. Symbols are as described for a.