IgG Subtype Is Correlated with Efficiency of Passive Protection and Effector Function of Anti-Herpes Simplex Virus Glycoprotein D Monoclonal Antibodies

Abstract IgG subclasses differ in their effector functions in a variety of in vitro assays. To assess the effect of antibody subclass differences on in vivo protective efficacy against herpes simplex virus (HSV), a series of subclass switch mutants was made from an anti-HSV glycoprotein D monoclonal antibody. Purified antibody was examined for the ability to protect against HSV-2 challenge in mice. IgG2a was found to be more effective than IgG1. This correlated both with activity in antibody-dependent cell-mediated cytotoxicity and with efficiency of complement-mediated neutralization. These data suggest that optimization of passive immunization against HSV requires consideration of antibody subclass.