Enhanced Potency of a Broadly Neutralizing HIV-1 Antibody In Vitro Improves Protection against Lentiviral Infection In Vivo.
Rudicell, R.S., Kwon, Y.D., Ko, S.Y., Pegu, A., Louder, M.K., Georgiev, I.S., Wu, X., Zhu, J., Boyington, J.C., Chen, X., Shi, W., Yang, Z.Y., Doria-Rose, N.A., McKee, K., O'Dell, S., Schmidt, S.D., Chuang, G.Y., Druz, A., Soto, C., Yang, Y., Zhang, B., Zhou, T., Todd, J.P., Lloyd, K.E., Eudailey, J., Roberts, K.E., Donald, B.R., Bailer, R.T., Ledgerwood, J., Mullikin, J.C., Shapiro, L., Koup, R.A., Graham, B.S., Nason, M.C., Connors, M., Haynes, B.F., Rao, S.S., Roederer, M., Kwong, P.D., Mascola, J.R., Nabel, G.J.(2014) J Virol 88: 12669-12682
- PubMed: 25142607 
- DOI: https://doi.org/10.1128/JVI.02213-14
- Primary Citation of Related Structures:  
4OLU, 4OLV, 4OLW, 4OLX, 4OLY, 4OLZ, 4OM0, 4OM1 - PubMed Abstract: 
Over the past 5 years, a new generation of highly potent and broadly neutralizing HIV-1 antibodies has been identified. These antibodies can protect against lentiviral infection in nonhuman primates (NHPs), suggesting that passive antibody transfer would prevent HIV-1 transmission in humans. To increase the protective efficacy of such monoclonal antibodies, we employed next-generation sequencing, computational bioinformatics, and structure-guided design to enhance the neutralization potency and breadth of VRC01, an antibody that targets the CD4 binding site of the HIV-1 envelope. One variant, VRC07-523, was 5- to 8-fold more potent than VRC01, neutralized 96% of viruses tested, and displayed minimal autoreactivity. To compare its protective efficacy to that of VRC01 in vivo, we performed a series of simian-human immunodeficiency virus (SHIV) challenge experiments in nonhuman primates and calculated the doses of VRC07-523 and VRC01 that provide 50% protection (EC50). VRC07-523 prevented infection in NHPs at a 5-fold lower concentration than VRC01. These results suggest that increased neutralization potency in vitro correlates with improved protection against infection in vivo, documenting the improved functional efficacy of VRC07-523 and its potential clinical relevance for protecting against HIV-1 infection in humans.
Organizational Affiliation: 
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.