RSV infection of both multi-ciliated and airway basal cells.

<p>Apical exposure of HBEC to RSV-A2-GFP led to the infection of multi-ciliated cells. GFP⁺ (infected) cells were observed throughout the epithelium. These were identified as an acetylated α-tubulin⁺, ciliated cell (#, orange) by confocal imaging (A–B). Under these conditions, the sub-apical p63⁺ basal cells (red) did not become infected by RSV (B). Removal of the surface of the epithelium immediately before exposure to RSV resulted in numerous p63⁺GFP⁺ (*) cells 16 h later (C–D), consistent with infection of the airway basal cell. When well-differentiated cells were subjected to a mechanical scratch injury (E) followed by RSV infection multiple infected cells were clearly visible within the wound (F). A majority of the infected cells were determined as basal cells (p63⁺) by confocal microscopy (G–I). Presented are representative images from three independent experiments in two different donors. White bar indicates 1,000 µm in A, C, 50 um in B, D, 500 µm in E–F and 20 µm in G–I.