Figure 1

Expression of IFITMs in virus producing cells affects the production of infectious HIV-1 viral particles. A) Representation of the experimental scheme used here. HEK293T cells were transiently transfected with DNAs coding for single round infection-competent HIV-1 expressing GFP along with DNAs coding Flag-IFITMs. Virions were purified by ultracentrifugation through a 25% sucrose cushion, normalized by exogenous-RT (exo-RT) and used to challenge HeLaP4 or HEK293T cells bearing the appropriate HIV-1 receptors. Viral infectivity was measured 3 days later by flow cytometry in the case of GFP-coding viruses or 24 hours later by β-gal assay in the case of a complete NL4-3 proviral DNA (thanks to the HIV-1 LTR-β-gal reporter integrated in HeLaP4 cells). B) Typical FACS profiles obtained after this procedure. C) Normalized infectivity of viral particles obtained after flow cytometry analysis (left graph) or MAGI assay (right graph). D) As above, except that HIV-1 viruses coding GFP were pseudotyped with the indicated envelope proteins. E) As above, except that distinct retroviral vectors pseudotyped with VSVg and coding GFP were analyzed. F) As above, except that HIV-1 vectors bearing the indicated envelope were used to challenge the indicated target cells prior to flow cytometry analysis 3 days after infection. DCs and MDM were obtained after differentiation of primary human blood monocytes in GM-CSF/IL4 or M-CSF for 4 to 6 days. PBLs were activated with PHA/IL2 for 24 hours prior to viral challenge. All graphs present averages and SEM obtained from 4 to 6 independent experiments. *indicates statistically significant differences between WT and IFITMs conditions after a Student t test: p≤0,05.