FIG. 5.

(A) HIV-1 transcription is inhibited by IRF-1 siRNA expression. Total RNA was purified, at different time points, from Jurkat T cells stably expressing either IRF-1 or control siRNA, infected with the HIV-1 pHXBc2 molecular clone. Primary HIV-1 transcripts were monitored by real-time RT-PCR using specific primers for early transcripts (37) Levels from uninfected cells at 5 h were set as the basis of comparative results and for GAPDH, whose sequence is indicated in Materials and Methods. (B) RT-PCR analysis was performed for SeV N protein on RNA extracts from 10-h SeV-infected control and IRF-1 siRNA-expressing Jurkat cells. Data are normalized by the level of GAPDH mRNA expression in each sample and shown as relative expression units. Western blot analysis of IRF-1 levels was performed on whole-cell extracts from control and IRF-1 siRNA-expressing Jurkat cells infected with HIV-1 (A, upper panel) or SeV (B, upper panel); actin levels are also shown as loading control. (C) Total DNA from Jurkat T cells stably expressing either IRF-1 or control siRNA and infected with HIV-1 at the indicated time points was purified, and the HIV-1 gag DNA full reverse transcript was quantified by real-time PCR as indicated in Materials and Methods. Error bars indicate standard deviations.