RSV fusion: time for a new model

In this review we propose a partially hypothetical model of respiratory syncytial virus (RSV) binding and entry to the cell that includes the recently discovered RSV receptor nucleolin, in an attempt to stimulate further inquiry in this research area. RSV binding and entry is likely to be a two-step process, the first involving the attachment of the virus to the cell membrane, which may be enhanced by electrostatic interactions with cellular glycoproteins/heparin and the viral G protein, and the second involving fusion to the cell membrane mediated by the viral F protein and a specific cellular fusion receptor. With our recent discovery of nucleolin as a functional fusion receptor for RSV, comes the possibility of a number of new approaches to the development of novel strategies for RSV prophylaxis and therapy, as well as raising some new questions concerning the pathobiology of RSV infection and tropism.