Immunization with a vaccine combining herpes simplex virus 2 (HSV-2) glycoprotein C (gC) and gD subunits improves the protection of dorsal root ganglia in mice and …

S Awasthi, JM Lubinski, CE Shaw, SM Barrett… - Journal of …, 2011 - Am Soc Microbiol
S Awasthi, JM Lubinski, CE Shaw, SM Barrett, M Cai, F Wang, M Betts, S Kingsley…
Journal of virology, 2011Am Soc Microbiol
Attempts to develop a vaccine to prevent genital herpes simplex virus 2 (HSV-2) disease
have been only marginally successful, suggesting that novel strategies are needed.
Immunization with HSV-2 glycoprotein C (gC-2) and gD-2 was evaluated in mice and guinea
pigs to determine whether adding gC-2 to a gD-2 subunit vaccine would improve protection
by producing antibodies that block gC-2 immune evasion from complement. Antibodies
produced by gC-2 immunization blocked the interaction between gC-2 and complement …
Abstract
Attempts to develop a vaccine to prevent genital herpes simplex virus 2 (HSV-2) disease have been only marginally successful, suggesting that novel strategies are needed. Immunization with HSV-2 glycoprotein C (gC-2) and gD-2 was evaluated in mice and guinea pigs to determine whether adding gC-2 to a gD-2 subunit vaccine would improve protection by producing antibodies that block gC-2 immune evasion from complement. Antibodies produced by gC-2 immunization blocked the interaction between gC-2 and complement C3b, and passive transfer of gC-2 antibody protected complement-intact mice but not C3 knockout mice against HSV-2 challenge, indicating that gC-2 antibody is effective, at least in part, because it prevents HSV-2 evasion from complement. Immunization with gC-2 also produced neutralizing antibodies that were active in the absence of complement; however, the neutralizing titers were higher when complement was present, with the highest titers in animals immunized with both antigens. Animals immunized with the gC-2-plus-gD-2 combination had robust CD4+ T-cell responses to each immunogen. Multiple disease parameters were evaluated in mice and guinea pigs immunized with gC-2 alone, gD-2 alone, or both antigens. In general, gD-2 outperformed gC-2; however, the gC-2-plus-gD-2 combination outperformed gD-2 alone, particularly in protecting dorsal root ganglia in mice and reducing recurrent vaginal shedding of HSV-2 DNA in guinea pigs. Therefore, the gC-2 subunit antigen enhances a gD-2 subunit vaccine by stimulating a CD4+ T-cell response, by producing neutralizing antibodies that are effective in the absence and presence of complement, and by blocking immune evasion domains that inhibit complement activation.
American Society for Microbiology