Immunogenicity of recombinant vaccinia viruses that display the HIV type 1 envelope glycoprotein on the surface of infectious virions

A chimeric protein, consisting of the extracellular domain of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein attached to the transmembrane and cytoplasmic domains of the vaccinia virus B5R glycoprotein, is displayed on the surface of extracellular recombinant vaccinia virus particles, whereas the unmodified full-length HIV-1 glycoprotein is not (Katz E, et al., J Virol 1997;71:3178-3187). Here, we report that rabbits and mice inoculated with recombinant vaccinia viruses that express the chimeric protein developed higher HIV-specific antibody responses than animals inoculated with vaccinia virus that expressed the unmodified HIV glycoprotein. These data suggest that the immunogenicity of recombinant proteins may be enhanced by their presentation on the surface of vaccinia virus particles.