A RhoA-derived peptide inhibits syncytium formation induced by respiratorysyncytial virus and parainfluenza virus type 3

The fusion glycoproteins of human respiratory syncytial virus (RSV) and hum an parainfluenza virus type-3 (PIV-3) mediate virus entry and syncytium for mation. Interaction between the fusion protein of RSV and RhoA, a small GTP ase, facilitates virus-induced syncytium formation. We show here a RhoA-der ived peptide inhibits RSV and syncytium formation induced by RSV and PIV-3, both in vitro by inhibition of cell-to-cell fusion and in vivo by reductio n of peak titer by 2 log(10) in RSV-infected mice. These findings indicate that the interaction between these two paramyxovirus fusion proteins and Rh oA is an important target for new antiviral strategies.