Fig. 3

Knockdown of IFITM3 promotes the passage of PFV. A HT1080-shNC or HT1080-shIFITM3 cells were infected with the PFV virus stock (0.49 MOI). The cellular state and pathological changes were observed using an electron microscope at different time points following viral infection. The white arrows indicate syncytium. B The number of syncytia in multiple random fields 36 h after virus infection in A was counted. A total of 12 fields of view were included in three independent experiments. C, D HT1080-shNC or HT1080-shIFITM3 cells were infected with the PFV virus stock (0.17 MOI). Every 2 days following infection, the PFVL indicator cell lines were co-incubated with cell culture supernatants (1/2 µL) or HT1080 cells (1/20). Infected cells (0.03 × 10⁶) were supplemented with 10 times the number of uninfected shNC or shIFITM3 cells. The measured luciferase level of PFVL after co-incubation indicated the titer of the virus after passaging. Values were statistically evaluated using t tests. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. Data are representative of two (C, D) or three (B) independent experiments