Correspondence

Glycoprotein H (gH) homologues are found in all members of the herpes virus family, and gH is one of the virion envelope glycoproteins that is essential for virus entry. In this study, a recombinant soluble form of Herpes simplex virus type 1 (HSV-1) gH, in which the ectodomain is fused to the Fc-binding region of IgG, has been generated. This was expressed in mammalian cells together with gL and the resulting gHFc–gL heterodimer was purified using Protein A Sepharose. Low-affinity cell binding assays showed that gHFc–gL bound specifically to Vero cells and mutation of a potential integrin-binding motif, Arg-Gly-Asp (RGD), in gH abolished binding. CHO cells failed to bind in this assay. However, CHO cells expressing the human avb3 integrin bound efficiently to gHFc–gL, suggesting that HSV-1 gH can bind to cells using avb3 integrins and that this binding is mediated by the RGD motif in the gH ectodomain. The current view of Herpes simplex virus (HSV) entry is that it involves three steps. Initial adsorption of viruses to host cells is mediated by interaction with cell-surface glycosaminoglycans (GAGS). Glycoprotein (g) C is the major GAG-binding protein but gB also has GAG-bindin