Broadly Neutralizing Monoclonal Antibodies to the V3 Region of HIV-1 Can Be Elicited by Peptide Immunization

The third hypervariable region (V3) of the HIV-1 envelope gp120 protein contains the principal neutralizing domain. Most neutralizing antibodies directed toward this region are very type-specific. Conserved sequences do exist within this region, however, and may prove useful in developing vaccines and therapeutic monoclonal antibodies (MABs) capable of targeting diverse HIV-1 isolates. We have used synthetic peptides containing conserved V3 sequences as immunogens to produce a panel of neutralizing MABs. The characterization of these MABs is described here. In addition, a series of in vitro assays has been developed that may be useful in predicting the neutralization potential of individual antibodies.