DESCRIPTION: This proposal examines the role of the herpes simplex virus (HSV) IgG Fc receptor (FcR) in immune evasion. The goals of the proposal are to: (1) demonstrate the biologic significance of the HSV-1 FcR in vivo. This will be done using FcR mutant and rescued viruses. (2) Define the functional domains involved in HSV-1 and HSV-2 FcR activity. Mapping studies will explore the role of HSV-1 gI and HSV-2 gE and gI in FcR-mediated immune evasion. (3) Block HSV FcR-mediated immune evasion. The investigators propose a series of vaccine candidates designed to induce antibodies that will block FcR activity and hopefully improve HSV vaccine efficacy.