A role for herpes simplex virus type 1 glycoprotein E in induction of cell fusion.

The role of herpes simplex virus type 1 (HSV-1) glycoprotein E (gE) in the induction of multinucleate cell (syncytium) formation was investigated using monoclonal antibodies and a gE deletion mutant, R7023. We found that monoclonal antibodies directed against gE blocked HSV-1-induced syncytium formation in human cells. R7023 also failed to induce syncytium formation in tissue culture cells. The results indicate that gE, in addition to glycoproteins B, D, H and the gene sequence located between 0.732 and 0.745 map units, is involved in cell fusion. Thus, this important biological property appears to be regulated by several HSV-1 gene products.