FIG 3.

Influenza virus upregulates endothelial vWF and ICAM-1 expression. (A to C) Endothelial expression of vWF (A), ICAM-1 (B), and P-selectin (C) after influenza infection were measured by flow cytometry. Thrombin was used as a positive control in the P-selectin experiment, showing that influenza infection does not affect endothelial P-selectin expression. Histograms and graphs of relative mean fluorescence are representative of 2 to 3 experiments. *, P < 0.05 versus the control; isotype refers to isotype control antibody. (D) ICAM-1 and vWF are not required for flu-induced platelet-endothelial interaction, as the incubation of HMVECs with anti-vWF or anti-ICAM-1 blocking antibodies did not prevent influenza-induced platelet-endothelial adhesion. n = 3; *, P < 0.05 versus the control.