Promoted cell death of cells expressing human MxA by influenza virus infection.

Interferon-inducible MxA protein plays a crucial role in cellular protection from RNA virus infection, although the protection mechanism is not completely clarified. Here, we examined effects of MxA on either uninfected or influenza virus A/PR/8/34-infected cells. Viral protein synthesis was reduced in cells expressing MxA. Under serum-starved conditions, not only viral but also cellular protein synthesis was reduced by expression of MxA. Of interest is that MxA promoted cell death induced by apoptotic stimuli as well as influenza virus infection. These results lead to a possibility that MxA suppresses multiplication of influenza virus by affecting cellular functions including the apoptotic pathway.