Identification of Cross-Reactive Antigenic Target Regions for HIV Type 1-Specific Antibody-Dependent Cellular Cytotoxicity

Monkey-derived hyperimmune antisera against 40 peptides, together representing the entire envelope gp120 of HIV-1_LAI, were used to map antibody-dependent cellular cytotoxicity (ADCC) target regions. Four regions corresponding to amino acids 65–126,152–230, 248–330, and 445–466 were found to contain epitopes inducing ADCC activity not only against HIV-1_LAI-infected cells but also against cells infected with HIV-1_SF2 and clinical isolates of HTV-1. When comparing seroreactivity to the individual peptides with ADCC titers none of the regions seemed to be dominant. These results thus describe cross-reactive regions involved in the functional immunity against HIV-1 gp120.