Antibody 8ANC195 Reveals a Site of Broad Vulnerability on the HIV-1 Envelope Spike.
Scharf, L., Scheid, J.F., Lee, J.H., West, A.P., Chen, C., Gao, H., Gnanapragasam, P.N., Mares, R., Seaman, M.S., Ward, A.B., Nussenzweig, M.C., Bjorkman, P.J.(2014) Cell Rep 7: 785-795
- PubMed: 24767986 
- DOI: https://doi.org/10.1016/j.celrep.2014.04.001
- Primary Citation of Related Structures:  
4P9H, 4P9M - PubMed Abstract: 
Broadly neutralizing antibodies (bNAbs) to HIV-1 envelope glycoprotein (Env) can prevent infection in animal models. Characterized bNAb targets, although key to vaccine and therapeutic strategies, are currently limited. We defined a new site of vulnerability by solving structures of bNAb 8ANC195 complexed with monomeric gp120 by X-ray crystallography and trimeric Env by electron microscopy. The site includes portions of gp41 and N-linked glycans adjacent to the CD4-binding site on gp120, making 8ANC195 the first donor-derived anti-HIV-1 bNAb with an epitope spanning both Env subunits. Rather than penetrating the glycan shield by using a single variable-region CDR loop, 8ANC195 inserted its entire heavy-chain variable domain into a gap to form a large interface with gp120 glycans and regions of the gp120 inner domain not contacted by other bNAbs. By isolating additional 8ANC195 clonal variants, we identified a more potent variant, which may be valuable for therapeutic approaches using bNAb combinations with nonoverlapping epitopes.
Organizational Affiliation: 
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.