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Title: Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape

Abstract

A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not bemore » completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing antibodies and identifies a set of mutations in the gp120 C terminus that exposes the membrane-proximal external region of gp41, with potential utility in HIV vaccine design.« less

Authors:
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Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE; National Institutes of Health (NIH)
OSTI Identifier:
1342234
Resource Type:
Journal Article
Resource Relation:
Journal Name: PLoS Pathogens; Journal Volume: 13; Journal Issue: 1
Country of Publication:
United States
Language:
ENGLISH
Subject:
59 BASIC BIOLOGICAL SCIENCES

Citation Formats

Wibmer, Constantinos Kurt, Gorman, Jason, Ozorowski, Gabriel, Bhiman, Jinal N., Sheward, Daniel J., Elliott, Debra H., Rouelle, Julie, Smira, Ashley, Joyce, M. Gordon, Ndabambi, Nonkululeko, Druz, Aliaksandr, Asokan, Mangai, Burton, Dennis R., Connors, Mark, Abdool Karim, Salim S., Mascola, John R., Robinson, James E., Ward, Andrew B., Williamson, Carolyn, Kwong, Peter D., Morris, Lynn, Moore, Penny L., and Desrosiers, Ronald C.. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape. United States: N. p., 2017. Web. doi:10.1371/journal.ppat.1006074.
Wibmer, Constantinos Kurt, Gorman, Jason, Ozorowski, Gabriel, Bhiman, Jinal N., Sheward, Daniel J., Elliott, Debra H., Rouelle, Julie, Smira, Ashley, Joyce, M. Gordon, Ndabambi, Nonkululeko, Druz, Aliaksandr, Asokan, Mangai, Burton, Dennis R., Connors, Mark, Abdool Karim, Salim S., Mascola, John R., Robinson, James E., Ward, Andrew B., Williamson, Carolyn, Kwong, Peter D., Morris, Lynn, Moore, Penny L., & Desrosiers, Ronald C.. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape. United States. doi:10.1371/journal.ppat.1006074.
Wibmer, Constantinos Kurt, Gorman, Jason, Ozorowski, Gabriel, Bhiman, Jinal N., Sheward, Daniel J., Elliott, Debra H., Rouelle, Julie, Smira, Ashley, Joyce, M. Gordon, Ndabambi, Nonkululeko, Druz, Aliaksandr, Asokan, Mangai, Burton, Dennis R., Connors, Mark, Abdool Karim, Salim S., Mascola, John R., Robinson, James E., Ward, Andrew B., Williamson, Carolyn, Kwong, Peter D., Morris, Lynn, Moore, Penny L., and Desrosiers, Ronald C.. Wed . "Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape". United States. doi:10.1371/journal.ppat.1006074.
@article{osti_1342234,
title = {Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape},
author = {Wibmer, Constantinos Kurt and Gorman, Jason and Ozorowski, Gabriel and Bhiman, Jinal N. and Sheward, Daniel J. and Elliott, Debra H. and Rouelle, Julie and Smira, Ashley and Joyce, M. Gordon and Ndabambi, Nonkululeko and Druz, Aliaksandr and Asokan, Mangai and Burton, Dennis R. and Connors, Mark and Abdool Karim, Salim S. and Mascola, John R. and Robinson, James E. and Ward, Andrew B. and Williamson, Carolyn and Kwong, Peter D. and Morris, Lynn and Moore, Penny L. and Desrosiers, Ronald C.},
abstractNote = {A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing antibodies and identifies a set of mutations in the gp120 C terminus that exposes the membrane-proximal external region of gp41, with potential utility in HIV vaccine design.},
doi = {10.1371/journal.ppat.1006074},
journal = {PLoS Pathogens},
number = 1,
volume = 13,
place = {United States},
year = {Wed Jan 11 00:00:00 EST 2017},
month = {Wed Jan 11 00:00:00 EST 2017}
}
  • The isolation of human monoclonal antibodies is providing important insights into the specificities that underlie broad neutralization of HIV-1 (reviewed in ref. 1). Here we report a broad and extremely potent HIV-specific monoclonal antibody, termed 35O22, which binds a novel HIV-1 envelope glycoprotein (Env) epitope. 35O22 neutralized 62% of 181 pseudoviruses with a half-maximum inhibitory concentration (IC 50) <50 μg ml -1. The median IC 50 of neutralized viruses was 0.033 μg ml -1, among the most potent thus far described. 35O22 did not bind monomeric forms of Env tested, but did bind the trimeric BG505 SOSIP.664. Mutagenesis and amore » reconstruction by negative-stain electron microscopy of the Fab in complex with trimer revealed that it bound to a conserved epitope, which stretched across gp120 and gp41. The specificity of 35O22 represents a novel site of vulnerability on HIV Env, which serum analysis indicates to be commonly elicited by natural infection. Binding to this new site of vulnerability may thus be an important complement to current monoclonal-antibody-based approaches to immunotherapies, prophylaxis and vaccine design.« less
  • The viral spike of HIV-1 is composed of three gp120 envelope glycoproteins attached noncovalently to three gp41 transmembrane molecules. Viral entry is initiated by binding to the CD4 receptor on the cell surface, which induces large conformational changes in gp120. These changes not only provide a model for receptor-triggered entry, but affect spike sensitivity to drug- and antibody-mediated neutralization. Although some of the details of the CD4-induced conformational change have been visualized by crystal structures and cryoelectron tomograms, the critical gp41-interactive region of gp120 was missing from previous atomic-level characterizations. Here we determine the crystal structure of an HIV-1 gp120more » core with intact gp41-interactive region in its CD4-bound state, compare this structure to unliganded and antibody-bound forms to identify structurally invariant and plastic components, and use ligand-oriented cryoelectron tomograms to define component mobility in the viral spike context. Newly defined gp120 elements proximal to the gp41 interface complete a 7-stranded {beta}-sandwich, which appeared invariant in conformation. Loop excursions emanating from the sandwich form three topologically separate - and structurally plastic - layers, topped off by the highly glycosylated gp120 outer domain. Crystal structures, cryoelectron tomograms, and interlayer chemistry were consistent with a mechanism in which the layers act as a shape-changing spacer, facilitating movement between outer domain and gp41-associated {beta}-sandwich and providing for conformational diversity used in immune evasion. A 'layered' gp120 architecture thus allows movement among alternative glycoprotein conformations required for virus entry and immune evasion, whereas a {beta}-sandwich clamp maintains gp120-gp41 interaction and regulates gp41 transitions.« less