Figure 2.

Human IFITMs inhibit foamy viral replication at the late step. At 3 days post-infection, every supernatant and cell lysates were harvested by centrifuging in 22,000 g for 15 min at 4°C. The supernatants were collected and stored at –70°C for later use. The collected cell lysates were also stored at –20°C for later usage. (A) Viral titers of each sample. Viral titers for measurement of infectious viruses present in the supernatants were evaluated by using the FeFAB assay. The results were presented as percentages of the non-transfected sample. All data are representative of three independent experiments performed in triplicate. (B) Confirmation of FFV Gag protein and IFITM proteins in cell lysates. Expression of FFV Gag protein and IFITM proteins in all the samples was confirmed by western blotting with FFV-Gag specific polyclonal antibody, IFITM1 (Santa Cruz), IFITM2 (Proteintech), and IFITM3 (Abcam) antibodies; β-actin (Santa Cruz) was used as the loading control. Data are expressed as the mean ± SEM from the triplicates of the three independent experiments. Statistical significance was analyzed with a two-paired Student’s t-test. * p < .05, **p < .01.