Mice genetic immunization with plasmid DNA encoding a secreted form of HSV-1 gB induces a protective immune response against herpes simplex virus type 1 infection.

Intramuscularly (i.m.) delivered plasmid DNA encoding a secreted form of glycoprotein B of herpes simplex virus type 1 (HSV-1 gB1s) was evaluated for the ability to elicit a protective immune response in Balb/c mice. Animals received three i.m. injections of a gB1s expression plasmid (pRP-RSV-gB1s) or of a wild-type transmembrane gB1 coding plasmid (pRP-RSV-gB1), while control mice were injected with the vector alone (pRP-RSV). A specific antibody response was observed in almost all immunized animals, and in most cases antibodies were also detected after 1 month in the absence of further vaccine boosts. Serum antibodies mostly displayed neutralizing activity against HSV-1. Glycoprotein B1s DNA immunization was also effective in protecting animals against the primary infection induced by a subsequent HSV-1 challenge and limited HSV-1 infection of sensitive ganglia.