Analysis of the surface topology of respiratory syncytial virus particles that form on the surface of virus-infected cells.

The surface topology of virus filaments on respiratory syncytial virus (RSV)-infected cells was examined using field emission gun-scanning electron microscopy (FEG-SEM) and atomic force microscopy (AFM). FEG-SEM analysis of the surface of RSV-infected cells labelled with an anti-G protein antibody revealed the presence of virus filaments and clusters of the G protein that were distributed intermittently along the surface of the virus filaments. Anti-G labelled RSV-infected cells that were thinly coated with chromium revealed a distinct structured surface topology that consisted of interlocking domains, and the G protein clusters were located in a subset of these structures. Imaging of RSV-infected cells using AFM revealed a similar structured surface topology on the virus filaments. These data provide the first detailed image analysis of the surface topology of the virus filaments that form in situ on RSV-infected cells and highlight the complexity of the spatial organisation within the viral envelope.