THE HERPES-SIMPLEX VIRUS-1 GLYCOPROTEIN-E (GE) MEDIATES IGG BINDING AND CELL-TO-CELL SPREAD THROUGH DISTINCT GE DOMAINS

Herpes simplex virus-1 (HSV-1) glycoprotein E (gE) is a multifunctiona l protein capable of both binding the Fc portion of IgG and mediating cell-to-cell spread of HSV-1. Here we report that the domain on gE inv olved in IgG binding is distinct from the domain involved in mediating cell-to-cell spread. To do this we have used five mutants of the HSV- 1 strain NS: NS-gE(null), a gE deletion virus; rNS-gE(null), a gE resc ued virus; NS-gE(339), a gE mutant virus with a four amino acid insert at position 339; rNS-gE(339), a gE rescue of NS-gE(339); and NS-gE(40 6), a gE mutant virus with the same four amino acids inserted at posit ion 406. Using IgG coated sheep red blood cells in resetting assays, w e show that the NS-gE(339) does not bind IgG, yet retains the ability to mediate normal cell-to-cell spread. These results demonstrate that the gE domain involved in IgG binding differs from the domain involved in cell-to-cell spread. (C) 1997 Academic Press.