Figure 1.

Schematic of Syncytia-Mediated Viral Spread

During traditional viral infections, spread occurs slowly by repeated infections of single cells following production of new infectious progeny. In syncytia-mediated viral spread, dissemination is facilitated by the expression of the fusion protein on the infected cells, which in turn, binds to various receptors on the neighboring cells. By spreading through the interaction of the fusion protein, dissemination is both more rapid and no longer limited to cells that express the viral receptor. This results in infection of more tumor cells than with a nonfusogenic virus.