Effect of brefeldin A on influenza A virus-induced apoptosis in vitro

Effect of brefeldin A (BFA) on influenza virus-infected cells was examined by measuring cell viability, microscopic examination, and DNA fragmentation analysis. When Madin-Darby canine kidney (MDCK) cells were infected with influenza A virus together with BFA treatment, virus-induced cell death was observed earlier than in the virus-infected cells without BFA treatment. By microscopic examination, the mode of cell death in virus-infected cells with BFA treatment appeared different from that of the cells without BFA treatment. Because influenza virus causes apoptosis in the host cells, extent of DNA fragmentation was compared between virus-infected cells with and without BFA treatment. BFA treatment resulted in inhibition of DNA fragmentation of virus-infected cells. Treatment of virus-infected cells with anti-oxidant (10 mM N-acetyl-L-cysteine) also inhibited DNA fragmentation of influenza virus-infected cells. A possible mechanism of BFA affecting influenza virus-induced apoptosis is discussed.