FIG. 3.
Effect of Vpr and/or MA NLS mutations on viral production in dividing and nondividing MT4 cells. (A to C) Dividing (A and B) or gamma-irradiated (B and C) MT4 cells were analyzed by fluorescence-activated cell sorting (A and C) and by [3H]thymidine incorporation (B). (A and C) The numbers of cells in G1/S and G2/M phases are shown as percentages of the total viable cells. (B) Histograms represent the level of cell-associated radioactivity following [3H]thymidine labeling of nonirradiated or irradiated (3,000 rads) MT4 cultures. (D and E) Dividing (D) or G2-growth-arrested (E) MT4 cells were infected with HIV-1 variants containing single or double mutations in the MA NLS and/or Vpr at an MOI of 0.01 TCID50/cell. Virus production in culture supernatants was monitored daily by RT activity or p24 ELISA. Data shown are representative of those for supernatants harvested at 3 days p.i. from three independent experiments and are for noninfected culture (bars 5) or cultures infected with wild-type (bars 1), Vpr− (bars 2), MA NLS− (bars 3), or Vpr− MA NLS− (bars 4) virus.