A recombinant avipoxvirus HIV-1 vaccine expressing interferon-gamma is safe and immunogenic in macaques

Complex recombinant fowlpoxvirus (rFPV) vaccines expressing both HIV-1 anti gens and type 1 cytokines could facilitate the induction of cellular immuni ty against HIV-1. A single rFPV expressing both HIV-1gag/pol and human inte rferon-gamma (FPVgag/pol-IFN gamma) was constructed and assessed as a thera peutic vaccine for safety and immunogenicity in macaques (Macaca nemestrina ) previously infected with HIV-1. FPV gag/pol-IFN gamma vaccinations were s afe and enhanced T cell proliferative responses to Gag antigens (but not co ntrol tetanus antigens). Enhanced CTL responses to gag/pol antigens were al so observed following IFN gamma expressing vaccinations. Since cellular imm unity may be critical to controlling or preventing HIV-1 infection, these o bservations suggest that avipox vectors co-expressing IFN gamma should be f urther evaluated as therapeutic or preventive HIV-1 vaccines. (C) 2000 Else vier Science Ltd. All rights reserved.