Faculty Opinions recommendation of Focused evolution of HIV-1 neutralizing antibodies revealed by structures and deep sequencing.

ABSTRACT All HIV-1-infected individuals develop strain-specific neutralizing antibodies to their infecting virus, which in some cases mature into broadly neutralizing antibodies. Defining the epitopes of strain-specific antibodies that overlap conserved sites of vulnerability might provide mechanistic insights into how broadly neutralizing antibodies arise. We previously described an HIV-1 clade C-infected donor, CAP257, who developed broadly neutralizing plasma antibodies targeting an N276 glycan-dependent epitope in the CD4 binding site. The initial CD4 binding site response potently neutralized the heterologous tier 2 clade B viral strain RHPA, which was used to design resurfaced gp120 antigens for single-B-cell sorting. Here we report the isolation and structural characterization of CAP257-RH1, an N276 glycan-dependent CD4 binding site antibody representative of the early CD4 binding site plasma response in donor CAP257. The cocrystal structure of CAP257-RH1 bound to RHPA gp120 revealed critical interactions with the N276 glycan, loop D, and V5, but not with aspartic acid 368, similarly to HJ16 and 179NC75. The CAP257-RH1 monoclonal antibody was derived from the immunoglobulin-variable IGHV3-33 and IGLV3-10 genes and neutralized RHPA but not the transmitted/founder virus from donor CAP257. Its narrow neutralization breadth was attributed to a binding angle that was incompatible with glycosylated V5 loops present in almost all HIV-1 strains, including the CAP257 transmitted/founder virus. Deep sequencing of autologous CAP257 viruses, however, revealed minority variants early in infection that lacked V5 glycans. These glycan-free V5 loops are unusual holes in the glycan shield that may have been necessary for initiating this N276 glycan-dependent CD4 binding site B-cell lineage. IMPORTANCE The conserved CD4 binding site on gp120 is a major target for HIV-1 vaccine design, but key events in the elicitation and maturation of different antibody lineages to this site remain elusive. Studies have shown that strain-specific antibodies can evolve into broadly neutralizing antibodies or in some cases act as helper lineages. Therefore, characterizing the epitopes of strain-specific antibodies may help to inform the design of HIV-1 immunogens to elicit broadly neutralizing antibodies. In this study, we isolate a narrowly neutralizing N276 glycan-dependent antibody and use X-ray crystallography and viral deep sequencing to describe how gp120 lacking glycans in V5 might have elicited these early glycan-dependent CD4 binding site antibodies. These data highlight how glycan holes can play a role in the elicitation of B-cell lineages targeting the CD4 binding site.

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A facile method of mapping HIV-1 neutralizing epitopes using chemically masked cysteines and deep sequencing

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2010256117 ◽

2020 ◽

Vol 117 (47) ◽

pp. 29584-29594

Author(s):

Rohini Datta ◽

Rohan Roy Chowdhury ◽

Kavyashree Manjunath ◽

Luke Elizabeth Hanna ◽

Raghavan Varadarajan

Keyword(s):

Deep Sequencing ◽

Mammalian Cells ◽

Neutralizing Antibodies ◽

Reverse Genetics ◽

Surface Display ◽

Design Strategies ◽

Viral Neutralization ◽

Antibody Specificities ◽

Tier 3 ◽

Hiv 1

Identification of specific epitopes targeted by neutralizing antibodies is essential to advance epitope-based vaccine design strategies. We report a facile methodology for rapid epitope mapping of neutralizing antibodies (NAbs) against HIV-1 Envelope (Env) at single-residue resolution, using Cys labeling, viral neutralization assays, and deep sequencing. This was achieved by the generation of a library of Cys mutations in Env glycoprotein on the viral surface, covalent labeling of the Cys residues using a Cys-reactive label that masks epitope residues, followed by infection of the labeled mutant virions in mammalian cells in the presence of NAbs. Env gene sequencing from NAb-resistant viruses was used to accurately delineate epitopes for the NAbs VRC01, PGT128, and PGT151. These agreed well with corresponding experimentally determined structural epitopes previously inferred from NAb:Env structures. HIV-1 infection is associated with complex and polyclonal antibody responses, typically composed of multiple antibody specificities. Deconvoluting the epitope specificities in a polyclonal response is a challenging task. We therefore extended our methodology to map multiple specificities of epitopes targeted in polyclonal sera, elicited in immunized animals as well as in an HIV-1–infected elite neutralizer capable of neutralizing tier 3 pseudoviruses with high titers. The method can be readily extended to other viruses for which convenient reverse genetics or lentiviral surface display systems are available.

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A1 The role of virus-antibody co-evolution in the development of a V3-glycan-directed HIV-1 broadly neutralizing antibody lineage

Virus Evolution ◽

10.1093/ve/vez002 ◽

2019 ◽

Vol 5 (Supplement_1) ◽

Author(s):

D Kitchin ◽

J Bhiman ◽

D Mvududu ◽

B Oosthuysen ◽

B Lambson ◽

...

Keyword(s):

Deep Sequencing ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Viral Escape ◽

Sequencing Data ◽

Virus Antibody ◽

Escape Mutants ◽

Broadly Neutralizing Antibody ◽

Hiv Envelope ◽

Hiv 1

Abstract Broadly neutralizing antibodies (bNAbs) are essential for a preventative HIV-1 vaccine but have not been elicited through vaccination. bNAbs develop in 20–30 per cent of HIV-1 infections and often target the V3-glycan epitope of the HIV envelope protein (Env). In these individuals, virus-antibody co-evolution is thought to drive the maturation of antibody lineages to neutralization breadth. We used deep sequencing of env genes and antibody transcripts from fourteen time points spanning the first 3 years of infection to characterize the virus-antibody co-evolution in donor CAP255 who developed V3-glycan-specific bNAbs. Sequencing and cloning of env genes, followed by neutralization assays, were used to identify Env mutations associated with neutralization escape from two bNAbs (CAP255.G3 and CAP255.C5) isolated at 149 weeks post-infection (wpi). Sequencing data indicated that CAP255 was co-infected by three related viral variants, all of which had an intact N332 glycan, which persisted in > 90 per cent of later viruses. A recombinant V3-region became fixed from 8 wpi, conferring slight neutralization resistance to CAP255.G3/C5 and other V3-glycan bNAbs. Later, T415R/K substitutions in V4 emerged by 51 wpi and were associated with complete viral escape from CAP255.G3/C5, though not from the polyclonal plasma response. All 93-week and later Envs were resistant to CAP255.G3/C5 and V3-glycan bNAb PGT135. Viral escape by 51 wpi suggested that the CAP255 bNAbs arose earlier, driving escape, but persisted to 149 weeks. This was supported by preliminary deep sequencing of the antibody repertoire that indicated bNAb lineage members were already present in the plasma at 39 wpi. Escape from V3-glycan bNAbs via T415R/K mutations have not previously been shown, suggesting a novel mode of recognition within the V3-glycan supersite. Further work will focus on identifying the bNAb-initiating Env and intermediate bNAb lineage members that were capable of engaging contemporaneous Env neutralization escape mutants. Characterization of Envs that engaged bNAb precursors, as well as those that selected for broader members of the bNAb lineage, will inform the design of immunogens capable of eliciting V3-glycan bNAbs in a novel HIV-1 vaccine regimen.

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Focused Evolution of HIV-1 Neutralizing Antibodies Revealed by Structures and Deep Sequencing

Science ◽

10.1126/science.1207532 ◽

2011 ◽

Vol 333 (6049) ◽

pp. 1593-1602 ◽

Cited By ~ 612

Author(s):

X. Wu ◽

T. Zhou ◽

J. Zhu ◽

B. Zhang ◽

I. Georgiev ◽

...

Keyword(s):

Deep Sequencing ◽

Neutralizing Antibodies ◽

Hiv 1

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A facile method of mapping HIV-1 neutralizing epitopes using chemically masked cysteines and deep sequencing

10.1101/2020.04.15.041996 ◽

2020 ◽

Author(s):

Rohini Datta ◽

Rohan Roy Chowdhury ◽

Kavyashree Manjunath ◽

Luke Elizabeth Hanna ◽

Raghavan Varadarajan

Keyword(s):

Deep Sequencing ◽

Mammalian Cells ◽

Neutralizing Antibodies ◽

Reverse Genetics ◽

Surface Display ◽

Design Strategies ◽

Viral Neutralization ◽

Antibody Specificities ◽

Tier 3 ◽

Hiv 1

AbstractIdentification of specific epitopes targeted by neutralizing antibodies is essential to advance epitope-based vaccine design strategies. We report a facile methodology for rapid epitope mapping of neutralizing antibodies (NAbs) against HIV-1 Envelope (Env) at single residue resolution, using Cys labeling, viral neutralization assays and deep sequencing. This was achieved by the generation of a library of Cys mutations in Env glycoprotein on the viral surface, covalent labeling of the Cys residues using a Cys reactive label that masks epitope residues, followed by infection of the labeled mutant virions in mammalian cells in the presence of NAbs. Env gene sequencing from NAb-resistant viruses was used to accurately delineate epitopes for the NAbs VRC01, PGT128 and PGT151. These agreed well with corresponding experimentally determined structural epitopes previously inferred from NAb:Env structures. HIV-1 infection is associated with complex and polyclonal antibody responses, typically composed of multiple antibody specificities. Deconvoluting the epitope specificities in a polyclonal response is a challenging task. We therefore extended our methodology to map multiple specificities of epitopes targeted in polyclonal sera, elicited in immunized animals as well as in an HIV-1 infected elite neutralizer capable of neutralizing Tier-3 pseudoviruses with high titers. The method can be readily extended to other viruses for which convenient reverse genetics or lentiviral surface display systems are available.

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