FIG 8.

Behaviors of the different IFITM3 mutants during target cell protection. (A) Experimental scheme used here to evaluate the abilities of the different IFITM3 mutants to protect target cells from HIV-1 infection. HEK293T cells were used as target cells due to their efficient transfection rates, following transient transfection with DNAs coding for the different IFITM3 mutants along with CD4 and CXCR4. (B) Two days after transfection, cells were analyzed by either WB or flow cytometry to determine the levels of expression of the different proteins. (C) Cells were then challenged with an equal dose of GFP-encoding HIV-1 (NL4-3 at an MOI of between 0.1 and 0.5), prior to flow cytometry analysis 2 to 3 days afterwards. The panels present typical results obtained, while the graph presents averages and SEM obtained from 5 to 7 independent experiments. *, P < 0.05 as determined by a Student t test for comparisons between the indicated mutant and WT IFITM3 (two tailed, unpaired). All mutants display P values of <0.05 when the same test is carried out in comparison to control cells (asterisks are not displayed for simplicity). (D) Correlative analysis between the extent of incorporation of the different IFITM3 mutants into virion particles and their levels of expression in cells.