Influenza infection induces apoptosis in human monocytes and monocyte-derived macrophages.

<p>(<b>A</b>) Influenza infection of MNC increases the percentage of apoptotic (AxV⁺/PI⁻) but not necrotic (AxV⁺/PI⁺) monocytes, as assessed by flow cytometry (MOI = 2). Infectious Udorn virus, but not UV-inactivated virus (UV) induces apoptosis in human MNC (<b>B</b>) and human macrophages (both Mph1 & Mph2) (<b>D</b>) in a dose dependent manner (<b>B</b> and <b>D</b>), with increasing numbers of apoptotic cells expressing HA with increasing virus dose in both cell types (MNC in <b>C</b>, and Mph1 in <b>E</b>). Bars represent means of 8 (<b>B</b>) or 3 (<b>D</b>) experiments ±SD, or representative examples (<b>A,C,E</b>). All experiments are 8 h p.i. *: p<0.05; **: p<0.01.