One of the goals of HIV-1 vaccine development is the elicitation of neutralizing antibodies against vulnerable regions on the envelope glycoproteins (Env) viral spike. Broadly neutralizing antibodies targeting the Env glycan-V3 region (also called the N332-glycan supersite) have previously been described, with several single lineages each derived from individual donors. We used a high-throughput B-cell culture method to isolate neutralizing antibodies from an HIV-1 infected donor with high serum neutralization breadth. Clonal relatives from three distinct antibody lineages were isolated. Each of these antibody lineages displayed modest breadth and potency, but shared several characteristics with the well-characterized glycan-V3 antibodies including dependence on glycans N332 and N301, VH4 family gene utilization, a CDRH2 insertion, and a longer than average CDRH3. In contrast to previously described glycan-V3 antibodies, the most potent of these antibodies preferentially recognized the native Env trimer compared to monomeric gp120. These data indicate the diversity of antibody specificities that target the glycan-V3 site. The quaternary binding preference of these antibodies suggests that that their elicitation likely requires presentation of a native-like trimeric Env immunogen.
Broadly neutralizing antibodies targeting the HIV-1 glycan-V3 region have previously been described with single lineages from individual donors. Here we describe three lineages from a single donor that each target glycan-V3. Unlike the previously described glycan-V3 antibodies, these mature antibodies bind preferentially to the native Env trimer and weakly to gp120 monomer. These data extend our knowledge of immune response recognition of the N332 supersite region and suggest that the mode of epitope recognition is more complex than previously anticipated.