Enhancement by phytohaemagglutinin of inactivation of herpes simplex virus by concanavalin A.

Inactivation of herpes simplex virus (HSV) by concanavalin A (Con A) was enhanced by treatment with phytohaemagglutinin (PHA)-P using a two-stage reaction procedure. Treatment with PHA alone failed to inactivate HSV. Enhancement of inactivation was also effective when HSV was exposed to PHA first. Our results suggest that the envelope of HSV contains receptor sites for Con A which are important in the infectious process, as well as receptor sites for PHA which are not critical for infectivity. Direct interaction of Con A with PHA was demonstrated and the reaction was reversed by alpha-methyl-D-glucoside. The data indicate that PHA stabilized the binding of Con A to the virus since reversal of inactivation by alpha-methyl-D-glucoside was minimal following treatment with Con A and PHA. Con A inactivated only enveloped virions and enhancement by PHA was a general phenomenon.