FIG. 7.

trans-complementation assays. (A) Huh-7w7 cells were electroporated with a core protein deletion mutant, JFH1/Δcore (62-160). At 72 h postelectroporation, cells were seeded onto 35-mm wells of a six-well cell culture plate and cultured overnight. Cells were transfected with empty pcDNA3.1 or with plasmids expressing the wt or mutant core proteins. Infectious virus production was assayed at 48 h posttransfection as described in Materials and Methods. (B) Western blot analysis of electroporated cells at 48 h posttransfection. Results for core protein and actin are shown as controls of transfection. (C) Electroporated Huh-7w7 cells with mutant genomes were passaged at 72 h postelectroporation as in panel A. Cells were then transfected with the pcDNA/core-wt plasmid, and infectivity was titrated at 48 h posttransfection as described in Materials and Methods. An empty pcDNA plasmid was used as a negative control. Means and standard errors of the means of results from at least duplicate electroporations are shown. (D) Supernatant of JFH1/Δcore (62-160)-electroporated Huh-7w7 cells that were trans-complemented with wt core protein was used to infect naïve Huh-7 cells. Cells were fixed at 48 h postinoculation, and immunostaining was performed with anti-core protein and anti-NS5A antibodies (upper panel). Supernatant of wt-electroporated Huh-7w7 cells was used as a control (lower panel).