| Popis: |
Background In a previous study, we described the diverse growth capabilities of circulating seasonal influenza A virus (IAV) with low to high viral copies in vitro. In this study, we analyzed the cause of differences in growth capability by evaluating Interferon-β and antiviral interferon-stimulated genes (ISGs) expression. Methods A549 cells (3.0x105 cells) were inoculated with circulating seasonal IAV strains for 6 and 24 h. In cells inoculated for 6 h, IAV production was assessed by IAV-RNA copies in culture supernatant and cell pellets for gene expression evaluation. At 24 hours post-infection, cells were collected for IFN-β and ISG-15 protein expression. JAK/STAT pathway inhibitor, pyridone 6 (P6) was used to evaluate the influence of ISGs on the growth capability of seasonal IAV. Results A549 cells inoculated with seasonal IAV strains with high growth capability expressed less IFN-β and ISGs, whereas low growth capability strains expressed more IFN-β and ISGs. The use of a P6, a JAK/STAT inhibitor, suppressed the expression of ISGs and enhanced the viral copies of seasonal IAV strains with low growth capability. This result suggests that growth capability is regulated by ISG-mediated IFN-β production. Conclusion In this study, we provide a new insight into the mechanism of circulating seasonal IAV replication. Our study showed that the difference in the growth capability of circulating seasonal IAV strains is due to the regulation of antiviral ISGs. Inhibition of the JAK/STAT pathway permits seasonal IAV strains with low growth capability to enhance their viral copies by suppressing antiviral ISGs. Our results may contribute in developing new effective therapeutic strategies and reduce the risk of developing severe influenza disease. |
