ANTIBODY-RESPONSE AND PROTECTIVE CAPACITY OF PLASMID VACCINES EXPRESSING 3 DIFFERENT HERPES-SIMPLEX VIRUS GLYCOPROTEINS

Plasmid expression vectors were constructed that contained the genes e ncoding herpes simplex virus 1 (HSV-1) glycoproteins C (gC), D (gD), a nd E (gE), Mice receiving two intramuscular injections of expression p lasmid (50 mu g) produced a specific HSV-1 antibody response. Mice rec eiving the go plasmid were protected against a lethal intraperitoneal challenge of HSV-1 (5 x 10(4) pfu) but not against more demanding chal lenge doses. Protection with gC or gE plasmid vaccination could be dem onstrated only if the inoculating dose of DNA was increased to 250 mu g. In contrast, all mice immunized with vaccinia recombinants expressi ng either gC or gE survived HSV-1 challenge. Analysis of the HSV-1 ant ibody isotype produced by plasmid immunization revealed a response dom inated by IgG2a, Combination delivery of all three glycoprotein expres sion plasmids provided better protection against lethal challenge, but mice receiving the combination were still not able to withstand incre ased challenge doses of virus.