Structural basis for HIV-1 gp120 recognition by a germ-line version of a broadly neutralizing antibody

ABSTRACT Soluble envelope glycoprotein (Env) trimers (SOSIP.664 gp140) are attractive HIV-1 vaccine candidates, with structures that mimic the native membrane-bound Env spike (gp160). Since engineering trimers can be limited by the difficulty of rationally predicting beneficial mutations, here we used a more comprehensive mutagenesis approach with the goal of identifying trimer variants with improved antigenic and stability properties. We created 341 cysteine pairs at predicted points of stabilization throughout gp140, 149 proline residue substitutions at every residue of the gp41 ectodomain, and 362 space-filling residue substitutions at every hydrophobic and aromatic residue in gp140. The parental protein target, the clade B strain B41 SOSIP.664 gp140, does not bind the broadly neutralizing antibody PGT151 and so was used here to identify improved variants that also provide insight into the structural basis for Env antigenicity. Each of the 852 mutants was expressed in human cells and screened for antigenicity using four different monoclonal antibodies (MAbs), including PGT151. We identified 29 trimer variants with antigenic improvements derived from each of the three mutagenesis strategies. We selected four variants (Q203F, T538F, I548F, and M629P) for more comprehensive biochemical, structural, and antigenicity analyses. The T538F substitution had the most beneficial effect overall, including restoration of the PGT151 epitope. The improved B41 SOSIP.664 trimer variants identified here may be useful for vaccine and structural studies. IMPORTANCE Soluble Env trimers have become attractive HIV-1 vaccine candidates, but the prototype designs are capable of further improvement through protein engineering. Using a high-throughput screening technology (shotgun mutagenesis) to create and evaluate 852 variants, we were able to identify sequence changes that were beneficial to the antigenicity and stability of soluble trimers based on the clade B B41 env gene. The strategies described here may be useful for identifying a wider range of antigenically and structurally improved soluble trimers based on multiple genotypes for use in programs intended to create a broadly protective HIV-1 vaccine.

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Structural Basis for Broad HIV-1 Neutralization by a Novel MPER-Specific Human Broadly Neutralizing Antibody

SSRN Electronic Journal ◽

10.2139/ssrn.3416843 ◽

2019 ◽

Author(s):

Dora Pinto ◽

Craig Fenwick ◽

Christophe Caillat ◽

Chiara Silacci ◽

Serafima Guseva ◽

...

Keyword(s):

Neutralizing Antibody ◽

Structural Basis ◽

Broadly Neutralizing Antibody ◽

Hiv 1

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Faculty Opinions recommendation of Structure of HIV-1 gp120 V1/V2 domain with broadly neutralizing antibody PG9.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.13399007.14768128 ◽

2011 ◽

Author(s):

Eric Hunter ◽

Cynthia Derdeyn

Keyword(s):

Neutralizing Antibody ◽

Broadly Neutralizing Antibody ◽

Hiv 1

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Faculty Opinions recommendation of HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726236758.793517678 ◽

2016 ◽

Author(s):

James Tartaglia ◽

Sanjay Phogat

Keyword(s):

B Cells ◽

Neutralizing Antibody ◽

Broadly Neutralizing Antibody ◽

Precursor B Cells ◽

Hiv 1

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Faculty Opinions recommendation of Priming HIV-1 broadly neutralizing antibody precursors in human Ig loci transgenic mice.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.726724591.793524291 ◽

2016 ◽

Author(s):

Noah Sather

Keyword(s):

Transgenic Mice ◽

Neutralizing Antibody ◽

Broadly Neutralizing Antibody ◽

Hiv 1

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Myomedin scaffold variants targeted to 10E8 HIV-1 broadly neutralizing antibody mimic gp41 epitope and elicit HIV-1 virus-neutralizing sera in mice

Virulence ◽

10.1080/21505594.2021.1920251 ◽

2021 ◽

Vol 12 (1) ◽

pp. 1271-1287

Author(s):

Milan Kuchař ◽

Petr Kosztyu ◽

Veronika Daniel Lišková ◽

Jiří Černý ◽

Hana Petroková ◽

...

Keyword(s):

Neutralizing Antibody ◽

Broadly Neutralizing Antibody ◽

Hiv 1

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Differences in the Binding Affinity of an HIV-1 V2 Apex-Specific Antibody for the SIVsmm/macEnvelope Glycoprotein Uncouple Antibody-Dependent Cellular Cytotoxicity from Neutralization

mBio ◽

10.1128/mbio.01255-19 ◽

2019 ◽

Vol 10 (4) ◽

Cited By ~ 6

Author(s):

Benjamin von Bredow ◽

Raiees Andrabi ◽

Michael Grunst ◽

Andres G. Grandea ◽

Khoa Le ◽

...

Keyword(s):

Binding Affinity ◽

Specific Antibody ◽

Neutralizing Antibody ◽

Glycosylation Site ◽

Antibody Binding ◽

Cellular Cytotoxicity ◽

Antibody Dependent Cellular Cytotoxicity ◽

Broadly Neutralizing Antibody ◽

Infected Cells ◽

Hiv 1

ABSTRACTAs a consequence of their independent evolutionary origins in apes and Old World monkeys, human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency viruses of the SIVsmm/maclineage express phylogenetically and antigenically distinct envelope glycoproteins. Thus, HIV-1 Env-specific antibodies do not typically cross-react with the Env proteins of SIVsmm/macisolates. Here we show that PGT145, a broadly neutralizing antibody to a quaternary epitope at the V2 apex of HIV-1 Env, directs the lysis of SIVsmm/mac-infected cells by antibody-dependent cellular cytotoxicity (ADCC) but does not neutralize SIVsmm/macinfectivity. Amino acid substitutions in the V2 loop of SIVmac239 corresponding to the epitope for PGT145 in HIV-1 Env modulate sensitivity to this antibody. Whereas a substitution in a conserved N-linked glycosylation site (N171Q) eliminates sensitivity to ADCC, a lysine-to-serine substitution in this region (K180S) increases ADCC and renders the virus susceptible to neutralization. These differences in function correlate with an increase in the affinity of PGT145 binding to Env on the surface of virus-infected cells and to soluble Env trimers. To our knowledge, this represents the first instance of an HIV-1 Env-specific antibody that cross-reacts with SIVsmm/macEnv and illustrates how differences in antibody binding affinity for Env can differentiate sensitivity to ADCC from neutralization.IMPORTANCEHere we show that PGT145, a potent broadly neutralizing antibody to HIV-1, directs the lysis of SIV-infected cells by antibody-dependent cellular cytotoxicity but does not neutralize SIV infectivity. This represents the first instance of cross-reactivity of an HIV-1 Env-specific antibody with SIVsmm/macEnv and reveals that antibody binding affinity can differentiate sensitivity to ADCC from neutralization.

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Vaccines and Broadly Neutralizing Antibodies for HIV-1 Prevention

Annual Review of Immunology ◽

10.1146/annurev-immunol-080219-023629 ◽

2020 ◽

Vol 38 (1) ◽

pp. 673-703 ◽

Cited By ~ 12

Author(s):

Kathryn E. Stephenson ◽

Kshitij Wagh ◽

Bette Korber ◽

Dan H. Barouch

Keyword(s):

Clinical Trials ◽

Neutralizing Antibodies ◽

Passive Immunization ◽

Neutralizing Antibody ◽

Broadly Neutralizing Antibodies ◽

Aids Pandemic ◽

Broadly Neutralizing Antibody ◽

Early Phase Clinical Trials ◽

Hiv 1 ◽

Review Current

Development of improved approaches for HIV-1 prevention will likely be required for a durable end to the global AIDS pandemic. Recent advances in preclinical studies and early phase clinical trials offer renewed promise for immunologic strategies for blocking acquisition of HIV-1 infection. Clinical trials are currently underway to evaluate the efficacy of two vaccine candidates and a broadly neutralizing antibody (bNAb) to prevent HIV-1 infection in humans. However, the vast diversity of HIV-1 is a major challenge for both active and passive immunization. Here we review current immunologic strategies for HIV-1 prevention, with a focus on current and next-generation vaccines and bNAbs.

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A Glycoconjugate Antigen Based on the Recognition Motif of a Broadly Neutralizing Human Immunodeficiency Virus Antibody, 2G12, Is Immunogenic but Elicits Antibodies Unable To Bind to the Self Glycans of gp120

Journal of Virology ◽

10.1128/jvi.00293-08 ◽

2008 ◽

Vol 82 (13) ◽

pp. 6359-6368 ◽

Cited By ~ 85

Author(s):

Rena D. Astronomo ◽

Hing-Ken Lee ◽

Christopher N. Scanlan ◽

Ralph Pantophlet ◽

Cheng-Yuan Huang ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Neutralizing Antibody ◽

Humoral Immune ◽

Aids Vaccine ◽

Humoral Immune Responses ◽

Copy Numbers ◽

Immunodeficiency Virus ◽

Broadly Neutralizing Antibody ◽

Hiv 1

ABSTRACT The glycan shield of human immunodeficiency virus type 1 (HIV-1) gp120 contributes to viral evasion from humoral immune responses. However, the shield is recognized by the HIV-1 broadly neutralizing antibody (Ab), 2G12, at a relatively conserved cluster of oligomannose glycans. The discovery of 2G12 raises the possibility that a carbohydrate immunogen may be developed that could elicit 2G12-like neutralizing Abs and contribute to an AIDS vaccine. We have previously dissected the fine specificity of 2G12 and reported that the synthetic tetramannoside (Man4) that corresponds to the D1 arm of Man9GlcNAc2 inhibits 2G12 binding to gp120 as efficiently as Man9GlcNAc2 itself, indicating the potential use of Man4 as a building block for creating immunogens. Here, we describe the development of neoglycoconjugates displaying variable copy numbers of Man4 on bovine serum albumin (BSA) molecules by conjugation to Lys residues. The increased valency enhances the apparent affinity of 2G12 for Man4 up to a limit which is achieved at ∼10 copies per BSA molecule, beyond which no further enhancement is observed. Immunization of rabbits with BSA-(Man4)14 elicits significant serum Ab titers to Man4. However, these Abs are unable to bind gp120. Further analysis reveals that the elicited Abs bind a variety of unbranched and, to a lesser extent, branched Man9 derivatives but not natural N-linked oligomannose containing the chitobiose core. These results suggest that Abs can be readily elicited against the D1 arm; however, potential differences in the presentation of Man4 on neoglycoconjugates, compared to glycoproteins, poses challenges for eliciting anti-mannose Abs capable of cross-reacting with gp120 and HIV-1.

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