Influenza virus NS1 protein induces apoptosis in cultured cells

The importance of influenza viruses as worldwide pathogens in humans, domes tic animals, and poultry is well recognized. Discerning how influenza virus es interact with the host at a cellular level is crucial for a better under standing of viral pathogenesis. Influenza viruses induce apoptosis through mechanisms involving the interplay of cellular and viral factors that may d epend on the cell type. However, it is unclear which viral genes induce apo ptosis. In these studies, we show that the expression of the nonstructural (NS) gene of influenza A virus is sufficient to induce apoptosis in MDCK an d HeLa cells. Further studies showed that the multimerization domain of the NS1 protein but not the effector domain is required for apoptosis. However , this mutation is not sufficient to inhibit apoptosis using whole virus.