FIG. 6.
Propagation of replication-competent PPT mutant virus. The PPTSUB mutant was introduced into the background of NL4-3Δnef (see the text) and propagated in a multiround infection using 80 ng of p24 antigen. At each time point beginning at day 6, 2 × 105 infected cells and 2 × 105 uninfected cells were seeded to the plate. WT PPT, solid line; PPTSUB, dotted line. Infectivity was measured using a p24 ELISA at each time point. The inactivated viral control showed no detectable p24 antigen. The measurements were done in triplicate, with error bars representing 1 standard deviation.