Efficient protein boosting after plasmid DNA or recombinant adenovirus immunization with HIV-1 vaccine constructs.

DNA plasmids and recombinant adenovirus serotype-5 (rAd5) vectors are being studied in human clinical trials as HIV-1 vaccine candidates. Each elicits robust T-cell responses and modest antibody levels. Since protein immunization alone elicits antibody but not CD8 T-cell responses, we studied protein boosting of DNA and rAd5 HIV-1 vaccine vectors.

Cross-clade recognition and neutralization by the V3 region from clade C human immunodeficiency virus-1 envelope.

To understand the cross-reactivity of antibodies directed against variable regions of human immunodeficiency virus-1 (HIV-1) envelope (Env), chimeric immunogens were prepared from different clades with modifications in variable regions, and the resulting neutralizing antibody response was evaluated. The V3-specific neutralization activity induced by a clade B immunogen was limited to clade B viruses and was blocked by a clade B V3 peptide, but not by analogous clade A or C V3 peptides. In contrast, the V3 response elicited by a clade C immunogen cross-reacted with sensitive clade B viruses.