A) The differential replication profiles of IN mutant viruses within the loop
on HIV-1 single-cycle replication. 293T cells were co-transfected with an RT/IN/Env-deleted HIV-1 provirus NLlucΔBglΔRI, each CMV-Vpr-RT-IN (wt/mut) expressor and a VSV-G expressor to generate single round replication competent virus. To test the effect of different IN mutant viruses on HIV-1 infection, C8166 T cells were infected with equal amount of VSV-G pseudotyped IN mutant viruses (adjust by p24 level) for 48 h. 1 × 106 cells were collected and cell-associated luciferase activity was measured by luciferase assay at 48 h post-infection. B) Followed by 12 h infection with single cycle replicating viruses on dividing C8166 T cells, total DNA was extracted and amplified for total viral DNA and human β-globin gene using corresponding primers by Real time PCR. Total HIV-1 DNA levels were expressed as copy numbers per cell, with DNA template normalized by the amplification of the β-globin gene. NC: negative control or 70°C inactivated wt virus.