GLYCOPROTEIN-C-INDEPENDENT BINDING OF HERPES-SIMPLEX VIRUS TO CELLS REQUIRES CELL-SURFACE HEPARAN-SULFATE AND GLYCOPROTEIN-B

Previous studies have shown that the initial interaction of herpes sim plex virus (HSV) with cells is binding to heparan sulphate and that HS V-1 glycoprotein C (gC) is principally responsible for this binding. A lthough gC-negative viral mutants are impaired for binding and entry, they retain significant infectivity. The purpose of the studies report ed here was to explore the requirements for infectivity of gC-negative HSV-1 mutants. We found that absence or alteration of cell surface he paran sulphate significantly reduced the binding of gC-negative mutant virus and rendered cells resistant to infection, shown previously for the wild-type virus. We isolated a recombinant double-mutated HSV str ain that produces virions devoid of both of the known heparin-binding glycoproteins, gB and gC. The drastically impaired binding of these mu tant virions to cells, relative to gC-negative and wild-type virions, indicates that gB mediates the binding of gC-negative virions to cells . Thus at least two HSV glycoproteins can independently mediate the bi nding of HSV to cell surface heparan sulphate to start the process of viral entry into cells.