Heparan sulfate as a mediator of herpes simplex virus binding to basement membrane

Explants of human lip and oral mucosa were infected with herpes simplex virus (HSV) in vitro and the expression of viral antigen was investigated by immunofluorescent antibody staining. Viral antigen was demonstrated in the cells of basal cell layer and lower prickle cell layers. Moreover, an accumulation of viral antigen in the epithelial-mesenchymal junction was observed. To examine the possibility that the basement membrane has an affinity for HSV, the interaction between HSV and major basement membrane components including type IV collagen, laminin, fibronectin, and heparan sulfate was investigated. When tested by a plaque-reduction assay, only heparan sulfate inhibited HSV plaque formation by competing for the virus adsorption to HEp-2 cells. The inhibitory effects of heparan sulfate and heparin were not affected by pre-incubation of these glycosaminoglycans with antithrombin III, whereas de-N-sulfation resulted in a significant reduction of their inhibitory activity. These findings suggest that heparan sulfate is involved in the binding of HSV to the basement membrane and that N-sulfated glucosamine residues of heparan sulfate are essential for HSV binding. The basement membrane may act as a reservoir of HSV in muco-cutaneous tissues.