Fig. 2.

Engineering HSV-1 for an oncolytic virus by deleting the ICP34.5 and ICP47 genes. A Workflow of the gene editing process of the O-HSV1 oncolytic virus in this study. B 293FT monolayers were infected with HSV-1, O-HSV1 (#1/#2/#3) and R3616 at an MOI of 1. ICP34.5 protein expression was detected by Western blot. C Recombinant oncolytic virus O-HSV1 was obtained from two rounds of selection of RFP⁺ and RFP⁻ plaques under a fluorescence microscope (scale bar at 500 µm). D Detection of the mRNA levels of ICP34.5 and ICP47 after virus infection in Hela cells by quantitative RT‒PCR. E Monolayers of Vero cells were untreated or pretreated with IFN-α before infection with HSV-1 and O-HSV1 virus. Viral titers were determined on Vero cells at different times postinfection (n=3). Human skin fibroblast (HSF) cells (F) and SW620 cells (G) were infected with different viruses, and virus replication was determined by a virus titration plaque assay (n=3). P values were determined using Student's t test. ns, not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.