Transcription factor binding sites involved in HIV-1 reactivation. (A) Scheme of HIV-1 LTR. (B) NP cells were infected with wt DHIV or with different LTR mutants. Mutations can be viewed in Figure S2. At 7 days after infection, cells were costimulated with antibodies to CD3 and CD28 for 3 days and assessed for intracellular p24 gag expression by flow cytometry. The percentage of p24-postive cells is indicated in each panel. Percentage of viral integration by Alu-PCR for each virus is indicated in blue (UD indicates undetectable). The experiment is representative of 3 different experiments with 3 different donors.