Vpx rescues HIV-1 from the antiviral state in MDDC prior to establishment of the provirus. MDDCs were treated with IFN-α for 24 h, and then treated with SIVMAC VLPs or media for 3 h, and finally challenged with a VSV-G-pseudotyped HIV-1NL4-3 GFP reporter virus. Total DNA was extracted from 5 × 106 MDDCs and qPCR was performed for HIV-1 full-length linear reverse transcription products (A), 2-LTR circles (B), and provirus (C). (D) Data from A, B, C, represented as (fold-rescue of HIV-1 by Vpx from IFN-α treatment) divided by (fold-rescue of HIV-1 by Vpx in the absence of exogenous IFN). Data represent one of at least three independent experiments. Error bars represent ± SEM (n = 4).