Comparative immunogenicity of human immunodeficiency virus particles and corresponding polypeptides in a DNA vaccine.

The immunogenicity of a plasmid DNA expression vector encoding both Gag and envelope (Env), which produced human immunodeficiency virus (HIV) type 1 virus-like particles (VLP), was compared to vectors expressing Gag and Env individually, which presented the same gene products as polypeptides. Vaccination with plasmids that generated VLP showed cellular immunity comparable to that of Gag and cell-mediated or humoral responses similar to those of Env as immunization with separate vectors. These data suggest that DNA vaccines encoding separated HIV polypeptides generate immune responses similar to those generated by viral particles.