IFITM3 Inhibits Influenza A Virus Infection by Preventing Cytosolic Entry
Figure 1
IFITM3 inhibits infection after viral binding but before viral transcription.
A) A549 cell lines were incubated on ice with H1N1 WSN/33 to permit viral-host binding. Cells were washed, fixed and immunostained for surface-bound HA protein, then analyzed by flow cytometry. Values given are percentage of cells staining for surface HA. Values are representative of three independent experiments. B) MDCK cells transduced with the empty vector control (Vector) or IFITM3 were incubated with A/Puerto Rico/8/34 H1N1 (PR8) on ice. Warm media was added at time zero. Cells were then fixed at the indicated time points and hybridized with RNA probes against the viral NP mRNA (red) and stained for DNA (blue), then imaged by confocal microscopy. Images are representative of three independent experiments. (Scale bar: 20 µm).