Deletion of the IRF-1/7 binding site (IRF-1 bs) from the HIV-1 LTR results in reduced infectivity. Day 2 MDDCs were treated with VSVG-pseudotyped HIV-1BaL-IRF-1 bs or HIV-1BaLwt at an MOI of 1 for 6-134 hours either alone in combination at various ratios. (A) The percentage of HIV-1–infected cells was determined by flow cytometry between 48 and 134 hours after infection. The mean data from 3 independent experiments are shown with standard error bars. There was a statistically significant difference between the rates of increase of the percentage of infected cells over time for HIV-1BaLwt versus HIV-1BaL-IRF-1 bs (P = .021 linear mixed-effects model). The mean difference in these infection rates was 0.028% per hour. (B) The greater the ratio of wild-type compared with mutant plasmid transfected, the greater the proportion of cells infected at 48 hours after infection. The mean data from 3 independent experiments are shown with standard error bars.
