Recombinant vesicular stomatitis virus expressing respiratory syncytial virus (RSV) glycoproteins: RSV fusion protein can mediate infection and cell fusion

The genes encoding the respiratory syncytial virus (RSV) attachment (G) and fusion (F) envelope glycoproteins were expressed separately as additional genes in recombinant vesicular stomatitis viruses (VSV). Cells infected wit h the VSV-RSV F recombinant formed large syncytia illustrating the fusion a ctivity of F in absence of other RSV proteins. Both F and G glycoproteins w ere expressed at the cell surface and incorporated into virions. Incorporat ion of these proteins did not require cytoplasmic tail sequences of VSV G. Using a compound, ammonium chloride, that raises the endosomal pH, we showe d that presence of the RSV F glycoprotein in the envelope of recombinant VS V allowed for infectivity through a low-pH-independent pathway. Recombinant VSV expressing RSV glycoproteins could be useful as an RSV vaccine. (C) 19 99 Academic Press.