Apoptosis was induced in influenza A viruses infected P815 cells.

<p>P815 cells were mock-treated or infected with H1N1, H5N1, or H7N2 at an MOI of 0.1 for 12 h. (A) Transmission electron microscopy showed ultrastructure of mock-treated and virus-infected cells. (B) A TUNEL assay was used to measure apoptosis in P815 cells using DNase as a positive control. Blue indicates nuclear staining and green indicates positive TUNEL staining due to the presence of apoptosis. The results shown here are representative of three different donors.