Suppression of the Biosynthesis of Cellular Sphingolipids Results in the Inhibition of the Maturation of Influenza Virus Particles in MDCK Cells

Abstract

To investigate involvement of cellular glycosphingolipids in the propagation of influenza viruses in host cells, MDCK cells were treated with inhibitors for sphingolipid biosynthesis, fumonisin B1 and d,l-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol. Continuous treatment of the cells with either inhibitor during pre- and post viral inoculation, but not the pretreatment alone, significantly reduced viral infection, but not viral attachment to the cells. Immunocytochemical analysis demonstrated that cellular distribution of hemagglutinin, a viral glycoprotein, was drastically altered when the cells were continuously treated with the inhibitors during pre- and post viral inoculation, but not the pretreatment alone. Our findings strongly suggest that cellular sphingolipids play important roles in the events after viral adsorption to the host cells.