Infliximab maintains plasmacytoid dendritic cells exposed to influenza virus in an IFNα secreting state. Peripheral blood mononuclear cells from control donors were exposed to influenza virus alone (Flu) or to influenza virus in the presence of infliximab. After 24 hours of incubation, the supernatant was collected and IFNα levels were measured by ELISA. The cell pellets were then washed, resuspended in fresh medium, and exposed for an additional 24 hours to influenza virus. Supernatants were analyzed by ELISA. Data are expressed as the mean ± standard error of the mean of three independent experiments.