Effects of hepatitis E virus infection on interferon production via ISG15

Figure 2 Hepatitis E virus open reading frame 3 protein enhances the production of Interferon-α and β and the expression of Interferon-stimulated gene 15 protein in C3A cells. C3A cells were transfected with 2 μg of either pORF3-EGFP (ORF3) or pEGFP-N1 empty vector (GFP), and the HEV mutant, leading to the loss of ORF3 protein expression (ΔORF3) for 48 h, untreated cells were used as the control (Con). Then, the cells and cell culture supernatants were harvested at different time points (0, 8, 12, 24, 48, 72 and 120 h). A: The concentrations of IFN-α and β were evaluated in cell culture supernatants at different time points (0, 8, 12, 24, 48, 72, 120 h) by enzyme-linked immunosorbent assay; B: The expression of ISG15 protein was detected at different time points (0, 8, 12, 24, 48, 72 and 120 h) by western blotting. The data are expressed as mean ± standard error of the mean. ^aP < 0.05, ^bP < 0.01. GFP: Green fluorescent protein; HEV: Hepatitis E virus; IFN: Interferon; ISG: IFN-stimulated gene; ORF: Open reading frame.