FIG. 3.
Effects of mutations in the gp41 cytoplasmic tail on infectivity of T-cell lines. Supernatants from transfected 293-T cells were normalized for RT activity and used to infect 3 × 106 cells. Cells were split on the days indicated, and RT activity of supernatants was determined. Experiments were performed twice in triplicate; typical results are shown for H9 (A) and CEM×174 (B). (C) Infection rate index, determined as (day of peak RT activity of WT)/(day of peak RT activity of mutant). Averages and standard deviations are shown. Missing standard deviations indicate that all cultures peaked at the same day, resulting in a standard deviation of zero.