Differential Antibody Responses to Conserved HIV-1 Neutralizing Epitopes in the Context of Multivalent Scaffolds and Native-Like gp140 Trimers

ABSTRACT Broadly neutralizing antibodies (bNAbs) have provided valuable insights into the humoral immune response to HIV-1. While rationally designed epitope scaffolds and well-folded gp140 trimers have been proposed as vaccine antigens, a comparative understanding of their antibody responses has not yet been established. In this study, we probed antibody responses to the N332 supersite and the membrane-proximal external region (MPER) in the context of heterologous protein scaffolds and native-like gp140 trimers. Ferritin nanoparticles and fragment crystallizable (Fc) regions were utilized as multivalent carriers to display scaffold antigens with grafted N332 and MPER epitopes, respectively. Trimeric scaffolds were also identified to stabilize the MPER-containing BG505 gp140.681 trimer in a native-like conformation. Following structural and antigenic evaluation, a subset of scaffold and trimer antigens was selected for immunization in BALB/c mice. Serum binding revealed distinct patterns of antibody responses to these two bNAb targets presented in different structural contexts. For example, the N332 nanoparticles elicited glycan epitope-specific antibody responses that could also recognize the native trimer, while a scaffolded BG505 gp140.681 trimer generated a stronger and more rapid antibody response to the trimer apex than its parent gp140.664 trimer. Furthermore, next-generation sequencing (NGS) of mouse splenic B cells revealed expansion of antibody lineages with long heavy-chain complementarity-determining region 3 (HCDR3) loops upon activation by MPER scaffolds, in contrast to the steady repertoires primed by N332 nanoparticles and a soluble gp140.664 trimer. These findings will facilitate the future development of a coherent vaccination strategy that combines both epitope-focused and trimer-based approaches. IMPORTANCE Both epitope-focused and trimer-based strategies are currently being explored in HIV-1 vaccine development, which aims to elicit broadly neutralizing antibodies (bNAbs) targeting conserved epitopes on the viral envelope (Env). However, little is known about the differences in antibody response to these bNAb targets presented by foreign scaffolds and native Env. In this study, a systematic effort was undertaken to design multivalent epitope scaffolds and soluble gp140.681 trimers with a complete antigenic surface, and to comparatively analyze the antibody responses elicited by these antigens to the N332 supersite and MPER in a mouse model. This study will inform both epitope-focused and trimer-based vaccine design and will facilitate integration of the two vaccine strategies. IMPORTANCE Both epitope-focused and trimer-based strategies are currently being explored in HIV-1 vaccine development, which aims to elicit broadly neutralizing antibodies (bNAbs) targeting conserved epitopes on the viral envelope (Env). However, little is known about the differences in antibody response to these bNAb targets presented by foreign scaffolds and native Env. In this study, a systematic effort was undertaken to design multivalent epitope scaffolds and soluble gp140.681 trimers with a complete antigenic surface, and to comparatively analyze the antibody responses elicited by these antigens to the N332 supersite and MPER in a mouse model. This study will inform both epitope-focused and trimer-based vaccine design and will facilitate integration of the two vaccine strategies.

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Broadly neutralizing antibodies and vaccine design against HIV-1 infection

Frontiers of Medicine ◽

10.1007/s11684-019-0721-9 ◽

2019 ◽

Vol 14 (1) ◽

pp. 30-42 ◽

Cited By ~ 5

Author(s):

Qian Wang ◽

Linqi Zhang

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Vaccine Design ◽

Therapeutic Interventions ◽

Type I ◽

Broadly Neutralizing Antibodies ◽

Dynamic Studies ◽

Immunodeficiency Virus ◽

Hiv 1 ◽

Remarkable Progress

AbstractRemarkable progress has been achieved for prophylactic and therapeutic interventions against human immunodeficiency virus type I (HIV-1) through antiretroviral therapy. However, vaccine development has remained challenging. Recent discoveries in broadly neutralizing monoclonal antibodies (bNAbs) has led to the development of multiple novel vaccine approaches for inducing bNAbs-like antibody response. Structural and dynamic studies revealed several vulnerable sites and states of the HIV-1 envelop glycoprotein (Env) during infection. Our review aims to highlight these discoveries and rejuvenate our endeavor in HIV-1 vaccine design and development.

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Reverse Immunology Approach to Define a New HIV-gp41-Neutralizing Epitope

Journal of Immunology Research ◽

10.1155/2019/9804584 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Karim Dorgham ◽

Nicolas Pietrancosta ◽

Amel Affoune ◽

Olivier Lucar ◽

Tahar Bouceba ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Molecular Design ◽

Docking Studies ◽

Viral Envelope ◽

Broadly Neutralizing Antibodies ◽

Immunodeficiency Virus ◽

Surface Envelope ◽

Hiv 1

The design of immunogens susceptible to elicit potent and broadly neutralizing antibodies against the human immunodeficiency virus type 1 (HIV-1) remains a veritable challenge in the course of vaccine development. Viral envelope proteins adopt different conformational states during the entry process, allowing the presentation of transient neutralizing epitopes. We focused on the highly conserved 3S motif of gp41, which is exposed to the surface envelope in its trimeric prefusion state. Vaccination with a W614A-modified 3S peptide induces in animals neutralizing anti-HIV-1 antibodies among which we selected clone F8. We used F8 as bait to select for W614A-3S phage-peptide mimics. Binding and molecular docking studies revealed that F8 interacts similarly with W614A-3S and a Mim_F8-1 mimotope, despite their lack of sequence homology, suggesting structural mimicry. Finally, vaccination of mice with the purified Mim_F8-1 phage elicited HIV-1-neutralizing antibodies that bound to the cognate W614A-3S motif. Collectively, our findings provide new insights into the molecular design of immunogens to elicit antibodies with neutralizing properties.

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HIV-1 Envelope Glycosylation and the Signal Peptide

10.20944/preprints202102.0210.v1 ◽

2021 ◽

Author(s):

Gregory S. Lambert ◽

Chitra Upadhyay

Keyword(s):

Signal Peptide ◽

Neutralizing Antibodies ◽

Vaccine Trial ◽

Vaccine Design ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

Structural Determinants ◽

Humoral Immune ◽

Env Protein ◽

Hiv 1

The RV144 trial represents the only vaccine trial to demonstrate any protective effect against HIV-1 infection. While the reason(s) for this protection are still being evaluated, it serves as justification for widespread efforts aimed at developing new, more effective HIV-1 vaccines. Advances in our knowledge of HIV-1 immunogens and host antibody responses to these immunogens are crucial to informing vaccine design. While the envelope (Env) protein is the only viral protein present on the surface of virions, it exists in a complex trimeric conformation and is decorated with an array of variable N-linked glycans, making it an important but difficult target for vaccine design. Thus far, efforts to elicit a protective humoral immune response using structural mimics of native Env trimers have been unsuccessful. Notably, the aforementioned N-linked glycans serve as a component of many of the epitopes crucial for the induction of potentially protective broadly neutralizing antibodies (bnAbs). Thus, a greater understanding of Env structural determinants, most critically Env glycosylation, will no doubt be of importance in generating effective immunogens. Recent studies have identified the HIV-1 Env signal peptide (SP) as an important contributor to Env glycosylation. Further investigation into the mechanisms by which the SP directs glycosylation will be important, both in the context of understanding HIV-1 biology and in order to inform HIV-1 vaccine design.

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Development of a Norovirus P Particle Platform for Eliciting Neutralizing Antibody Responses to the Membrane Proximal External Region of Human Immunodeficiency Virus Type 1 Envelope

Protein and Peptide Letters ◽

10.2174/0929866521666140616120955 ◽

2014 ◽

Vol 21 (12) ◽

pp. 1230-1239

Author(s):

Yang Zang ◽

Jinpeng Bi ◽

Dongchuan Du ◽

Xintao Liu ◽

Yan Zhang ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

External Region ◽

Membrane Proximal External Region ◽

Immunodeficiency Virus ◽

Hiv 1

Eliciting efficient broadly neutralizing antibodies (BnAbs) is an important goal that has yet to be achieved for human immunodeficiency type 1 (HIV-1) vaccine development, although they are rarely produced in virus-infected individuals. In particular, inducing specific neutralizing antibodies to the gp41 membrane proximal external region (MPER) has proven a difficult task. In this study, we introduce Norovirus P particles as a new platform to display the MPER epitope of HIV-1 as a vaccine with the aim of enhancing immune responses. The results showed that HIV-1 chimeric P particles were capable of inducing MPER-specific antibody responses in immunized guinea pigs, although only weakly neutralizing activity could be detected. These findings are consistent with other previous studies which have also focused on the well-studied 2F5 and 4E10 BnAbs. Our findings provide an alternate strategy for design of vaccines against HIV-1. However, great challenges remain in the effort to develop vaccines that can induce efficient HIV-1 neutralizing antibodies.

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Neutralizing Antibody Responses Induced by HIV-1 Envelope Glycoprotein SOSIP Trimers Derived from Elite Neutralizers

Journal of Virology ◽

10.1128/jvi.01214-20 ◽

2020 ◽

Vol 94 (24) ◽

Author(s):

Anna Schorcht ◽

Tom L. G. M. van den Kerkhof ◽

Christopher A. Cottrell ◽

Joel D. Allen ◽

Jonathan L. Torres ◽

...

Keyword(s):

Envelope Glycoprotein ◽

Neutralizing Antibodies ◽

High Titer ◽

Vaccine Design ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Tier 2 ◽

Broadly Neutralizing Antibodies ◽

Subtype B ◽

Hiv 1

ABSTRACT The induction of broadly neutralizing antibodies (bNAbs) is a major goal in vaccine research. HIV-1-infected individuals that develop exceptionally strong bNAb responses, termed elite neutralizers, can inform vaccine design by providing blueprints for the induction of similar bNAb responses. We describe a new recombinant native-like envelope glycoprotein (Env) SOSIP trimer, termed AMC009, based on the viral founder sequences of an elite neutralizer. The subtype B AMC009 SOSIP protein formed stable native-like trimers that displayed multiple bNAb epitopes. Overall, its structure at 4.3-Å resolution was similar to that of BG505 SOSIP.664. The AMC009 trimer resembled one from a second elite neutralizer, AMC011, in having a dense and complete glycan shield. When tested as immunogens in rabbits, the AMC009 trimers did not induce autologous neutralizing antibody (NAb) responses efficiently while the AMC011 trimers did so very weakly, outcomes that may reflect the completeness of their glycan shields. The AMC011 trimer induced antibodies that occasionally cross-neutralized heterologous tier 2 viruses, sometimes at high titer. Cross-neutralizing antibodies were more frequently elicited by a trivalent combination of AMC008, AMC009, and AMC011 trimers, all derived from subtype B viruses. Each of these three individual trimers could deplete the NAb activity from the rabbit sera. Mapping the polyclonal sera by electron microscopy revealed that antibodies of multiple specificities could bind to sites on both autologous and heterologous trimers. These results advance our understanding of how to use Env trimers in multivalent vaccination regimens and the immunogenicity of trimers derived from elite neutralizers. IMPORTANCE Elite neutralizers, i.e., individuals who developed unusually broad and potent neutralizing antibody responses, might serve as blueprints for HIV-1 vaccine design. Here, we studied the immunogenicity of native-like recombinant envelope glycoprotein (Env) trimers based on viral sequences from elite neutralizers. While immunization with single trimers from elite neutralization did not recapitulate the breadth and potency of neutralization observed in these infected individuals, a combination of three subtype B Env trimers from elite neutralizers resulted in some neutralization breadth within subtype B viruses. These results should guide future efforts to design vaccines to induce broadly neutralizing antibodies.

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HIV-1 Envelope Glycosylation and the Signal Peptide

Vaccines ◽

10.3390/vaccines9020176 ◽

2021 ◽

Vol 9 (2) ◽

pp. 176

Author(s):

Gregory S. Lambert ◽

Chitra Upadhyay

Keyword(s):

Signal Peptide ◽

Neutralizing Antibodies ◽

Vaccine Trial ◽

Vaccine Design ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

Structural Determinants ◽

Humoral Immune ◽

Env Protein ◽

Hiv 1

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Development of a structural epitope mimic: an idiotypic approach to HCV vaccine design

npj Vaccines ◽

10.1038/s41541-020-00269-1 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

Vanessa M. Cowton ◽

Ania M. Owsianka ◽

Valeria Fadda ◽

Ana Maria Ortega-Prieto ◽

Sarah J. Cole ◽

...

Keyword(s):

Genetic Diversity ◽

Mouse Model ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Vaccine Design ◽

Broadly Neutralizing Antibodies ◽

High Genetic Diversity ◽

Mutagenesis Screen ◽

Binding Characteristics ◽

Antigen Protein

AbstractHCV vaccine development is stymied by the high genetic diversity of the virus and the variability of the envelope glycoproteins. One strategy to overcome this is to identify conserved, functionally important regions—such as the epitopes of broadly neutralizing antibodies (bNAbs)—and use these as a basis for structure-based vaccine design. Here, we report an anti-idiotype approach that has generated an antibody that mimics a highly conserved neutralizing epitope on HCV E2. Crucially, a mutagenesis screen was used to identify the antibody, designated B2.1 A, whose binding characteristics to the bNAb AP33 closely resemble those of the original antigen. Protein crystallography confirmed that B2.1 A is a structural mimic of the AP33 epitope. When used as an immunogen B2.1 A induced antibodies that recognized the same epitope and E2 residues as AP33 and most importantly protected against HCV challenge in a mouse model.

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Plasma neutralizing antibodies in an infant with interclade HIV-1 superinfection preferentially neutralize superinfecting HIV-1 strains

10.1101/2020.12.10.420703 ◽

2020 ◽

Author(s):

Nitesh Mishra ◽

Shaifali Sharma ◽

Ayushman Dobhal ◽

Sanjeev Kumar ◽

Himanshi Chawla ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

Infected Infant ◽

Polyvalent Vaccine ◽

Clade C ◽

Sequential Infection ◽

Hiv 1

AbstractHIV-1 superinfection is defined as infection by an unrelated second strain of HIV-1 after seroconversion due to primary infecting strain and has been associated with development of breadth in the neutralizing antibody (nAb) response, altered disease progression and efficacy of antiretrovirals; though conflicting observations have also been reported. Superinfection has been reported in HIV-1 infected adults. Recently we observed that multivariant infection in infants was associated with early induction of plasma broadly neutralizing antibodies (bnAbs) targeting diverse autologous viruses, however, there is paucity of information on infants with HIV-1 superinfection. Furthermore, the mechanisms by which superinfection in an infant, after priming by an initial infection, potentiate the evolution of a bnAb response have not been evaluated. Herein, we performed a longitudinal analysis and observed evolution of nAb responses in an antiretroviral naïve perinatally HIV-1 infected infant, with interclade superinfection (clade C followed by a unique A1C recombinant). The nAb responses broadened rapidly after superinfection targeted an undefined glycan-dependent epitope on the superinfecting variant, while no enrichment of nAb response against the primary infecting strain occurred. Defining virological features in infants with sequential infection with highly divergent circulating viruses that improve nAb responses will contribute information that could be leveraged for optimization of multicomponent candidate vaccines.ImportanceHIV-1 infected infants develop bnAbs rapidly suggesting factors governing bnAb induction in infants are distinct from adults. HIV-1 superinfection is more common in adults whereas the stringent genetic bottleneck for transmission in infants often leads to infection by a single transmitted/founder HIV-1 strain. Longitudinal studies in infants with HIV-1 superinfection can provide key information on the viral factors that induce a bnAb response towards development of a polyvalent vaccine. Herein, we show that in infant who was sequentially infected with two HIV-1 strains from different clades, antibody responses were primarily generated against the superinfecting, second strain of HIV-1.These antibody responses were dependent on glycans, and targeted an undefined epitope in the C3V4 region of HIV-1 Env. A better understanding of how neutralizing antibody responses develop during natural HIV-1 superinfection in infants will provide information relevant to HIV Env vaccine development and evaluation.

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Broadly Neutralizing Antibodies (BNAbs): templates for HIV-1 vaccine design

Journal of Medical Discovery ◽

10.24262/jmd.2.4.17039 ◽

2017 ◽

Vol 2 (4) ◽

Cited By ~ 1

Author(s):

Lixin Yan ◽

◽

Lihong Liu ◽

Yilin Wang ◽

Xi Huang ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Design ◽

Broadly Neutralizing Antibodies ◽

Hiv 1

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Evaluation of HIV-1 latency reversal and antibody-dependent viral clearance by quantification of singly spliced HIV-1 vpu/env mRNA

Journal of Virology ◽

10.1128/jvi.02124-20 ◽

2021 ◽

Author(s):

Hongbo Gao ◽

Ayşe N. Ozantürk ◽

Qiankun Wang ◽

Gray H. Harlan ◽

Aaron J. Schmitz ◽

...

Keyword(s):

T Cells ◽

Neutralizing Antibodies ◽

Ex Vivo ◽

Viral Envelope ◽

Latent Reservoir ◽

Broadly Neutralizing Antibodies ◽

Major Barrier ◽

Hiv 1 ◽

Reversing Agents

The latent reservoir of HIV-1 is a major barrier for viral eradication. Potent HIV-1 broadly neutralizing antibodies (bNabs) have been used to prevent and treat HIV-1 infections in animal models and clinical trials. Combination of bNabs and latency-reversing agents (LRAs) is considered a promising approach for HIV-1 eradication. PCR-based assays that can rapidly and specifically measure singly spliced HIV-1 vpu/env mRNA are needed to evaluate the induction of the viral envelope production at the transcription level and bNab-mediated reservoir clearance. Here we reported a PCR-based method to accurately quantify the production of intracellular HIV-1 vpu/env mRNA. With the vpu/env assay, we determined the LRA combinations that could effectively induce vpu/env mRNA production in CD4+ T cells from ART-treated individuals. None of the tested LRAs were effective alone. A comparison between the quantitative viral outgrowth assay (Q-VOA) and the vpu/env assay showed that vpu/env mRNA production was closely associated with the reactivation of replication-competent HIV-1, suggesting that vpu/env mRNA was mainly produced by intact viruses. Finally, antibody-mediated in vitro killing in HIV-1-infected humanized mice demonstrated that the vpu/env assay could be used to measure the reduction of infected cells in tissues and was more accurate than the commonly used gag-based PCR assay which measured unspliced viral genomic RNA. In conclusion, the vpu/env assay allows convenient and accurate assessment of HIV-1 latency reversal and bNab-mediated therapeutic strategies. Importance HIV-1 persists in individuals on antiretroviral therapy (ART) due to the long-lived cellular reservoirs that contain dormant viruses. Recent discoveries of HIV-1-specific broadly neutralizing antibodies (bNabs) targeting HIV-1 Env protein rekindled the interest in antibody-mediated elimination of latent HIV-1. Latency-reversing agents (LRAs) together with HIV-1 bNabs is a possible strategy to clear residual viral reservoirs, which makes the evaluation of HIV-1 Env expression upon LRA treatment critical. We developed a PCR-based assay to quantify the production of intracellular HIV-1 vpu/env mRNA. Using patient CD4+ T cells, we found that induction of HIV-1 vpu/env mRNA required a combination of different LRAs. Using in vitro, ex vivo and humanized mouse models, we showed that the vpu/env assay could be used to measure antibody efficacy in clearing HIV-1 infection. These results suggest that the vpu/env assay can accurately evaluate HIV-1 reactivation and bNab-based therapeutic interventions.

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