Influence of cellular lipid content on influenza A virus replication

Influenza A virus (IAV) depends on the metabolism of its cellular host to provide energy and essential factors, including lipids, for viral replication. Previous studies have shown that fatty acids (FAs) play an important role in IAV replication and that inhibition of FA biosynthesis can diminish viral replication. However, cellular lipids can either be synthesized intracellularly or be imported from the extracellular environment. Interfering with FA import mechanisms may reduce the cellular lipid content and inhibit IAV replication. To test this hypothesis, MDCK and Detroit 562 cells were infected with IAV followed by exposure to palmitic acid and inhibitors of FA import. Replication of IAV significantly increased when infected cells were supplied with palmitic acid. This enhancement could be reduced by adding an FA import inhibitor. The addition of palmitic acid significantly increased the cellular lipid content, and this increased level was reduced by treatment with an FA import inhibitor. These results show that reducing the cellular lipid level might be an approach for IAV therapy.