Dissociation of HSV gL from gH by αvβ6- or αvβ8-integrin promotes gH activation and virus entry

Significance Entry of enveloped viruses into the cell requires the activation of viral glycoproteins, often mediated by cellular receptors. Herpesviruses infect cells via a multipartite system, which includes species-specific glycoproteins plus conserved apparatus gH/gL and gB. HSV makes use of αvβ6- or αvβ8-integrins as gH/gL receptors. The interaction of HSV gH/gL with integrins resulted in the dissociation of gL. The dissociation took place if all the actors of the entry apparatus were present, i.e., under conditions that lead to glycoprotein activation and virus entry. We propose that ( i ) gL is a regulator of gH and prevents its activation until integrins promote gL dissociation from gH/gL. ( ii ) Dissociation from an inhibitory regulator represents a previously unidentified mechanism of activation of viral fusion glycoproteins.