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

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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Nanoparticle Vaccines for Inducing HIV-1 Neutralizing Antibodies

Vaccines ◽

10.3390/vaccines7030076 ◽

2019 ◽

Vol 7 (3) ◽

pp. 76 ◽

Cited By ~ 15

Author(s):

Mitch Brinkkemper ◽

Kwinten Sliepen

Keyword(s):

Envelope Glycoprotein ◽

Neutralizing Antibodies ◽

Critical Role ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

Viral Membrane ◽

Immunodeficiency Virus ◽

Hiv 1

The enormous sequence diversity between human immunodeficiency virus type 1 (HIV-1) strains poses a major roadblock for generating a broadly protective vaccine. Many experimental HIV-1 vaccine efforts are therefore aimed at eliciting broadly neutralizing antibodies (bNAbs) that are capable of neutralizing the majority of circulating HIV-1 strains. The envelope glycoprotein (Env) trimer on the viral membrane is the sole target of bNAbs and the key component of vaccination approaches aimed at eliciting bNAbs. Multimeric presentation of Env on nanoparticles often plays a critical role in these strategies. Here, we will discuss the different aspects of nanoparticles in Env vaccination, including recent insights in immunological processes underlying their perceived advantages, the different nanoparticle platforms and the various immunogenicity studies that employed nanoparticles to improve (neutralizing) antibody responses against Env.

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Improved Elicitation of Neutralizing Antibodies against Primary Human Immunodeficiency Viruses by Soluble Stabilized Envelope Glycoprotein Trimers

Journal of Virology ◽

10.1128/jvi.75.3.1165-1171.2001 ◽

2001 ◽

Vol 75 (3) ◽

pp. 1165-1171 ◽

Cited By ~ 166

Author(s):

Xinzhen Yang ◽

Richard Wyatt ◽

Joseph Sodroski

Keyword(s):

Human Immunodeficiency Virus ◽

T Cell ◽

Envelope Glycoprotein ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Immunodeficiency Virus ◽

Human Immunodeficiency Viruses ◽

Functional Envelope ◽

Hiv 1

ABSTRACT Human immunodeficiency virus (HIV-1) envelope glycoprotein subunits, such as the gp120 exterior glycoprotein, typically elicit antibodies that neutralize T-cell-line-adapted (TCLA), but not primary, clinical isolates of HIV-1. Here we compare the immunogenicity of gp120 and soluble stabilized trimers, which were designed to resemble the functional envelope glycoprotein oligomers of primary and TCLA HIV-1 strains. For both primary and TCLA virus proteins, soluble stabilized trimers generated neutralizing antibody responses more efficiently than gp120 did. Trimers derived from a primary isolate elicited antibodies that neutralized primary and TCLA HIV-1 strains. By contrast, trimers derived from a TCLA isolate generated antibodies that neutralized only the homologous TCLA virus. Thus, soluble stabilized envelope glycoprotein trimers derived from primary HIV-1 isolates represent defined immunogens capable of eliciting neutralizing antibodies that are active against clinically relevant HIV-1 strains.

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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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Antibody responses induced by SHIV infection are more focused than those induced by soluble native HIV-1 envelope trimers in non-human primates

PLoS Pathogens ◽

10.1371/journal.ppat.1009736 ◽

2021 ◽

Vol 17 (8) ◽

pp. e1009736

Author(s):

Jelle van Schooten ◽

Marlies M. van Haaren ◽

Hui Li ◽

Laura E. McCoy ◽

Colin Havenar-Daughton ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Natural Infection ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Broadly Neutralizing Antibodies ◽

Antibody Diversity ◽

Infected Infant ◽

Immunodeficiency Virus ◽

Shiv Infection ◽

Hiv 1

The development of an effective human immunodeficiency virus (HIV-1) vaccine is a high global health priority. Soluble native-like HIV-1 envelope glycoprotein trimers (Env), including those based on the SOSIP design, have shown promise as vaccine candidates by inducing neutralizing antibody responses against the autologous virus in animal models. However, to overcome HIV-1’s extreme diversity a vaccine needs to induce broadly neutralizing antibodies (bNAbs). Such bNAbs can protect non-human primates (NHPs) and humans from infection. The prototypic BG505 SOSIP.664 immunogen is based on the BG505 env sequence isolated from an HIV-1-infected infant from Kenya who developed a bNAb response. Studying bNAb development during natural HIV-1 infection can inform vaccine design, however, it is unclear to what extent vaccine-induced antibody responses to Env are comparable to those induced by natural infection. Here, we compared Env antibody responses in BG505 SOSIP-immunized NHPs with those in BG505 SHIV-infected NHPs, by analyzing monoclonal antibodies (mAbs). We observed three major differences between BG505 SOSIP immunization and BG505 SHIV infection. First, SHIV infection resulted in more clonal expansion and less antibody diversity compared to SOSIP immunization, likely because of higher and/or prolonged antigenic stimulation and increased antigen diversity during infection. Second, while we retrieved comparatively fewer neutralizing mAbs (NAbs) from SOSIP-immunized animals, these NAbs targeted more diverse epitopes compared to NAbs from SHIV-infected animals. However, none of the NAbs, either elicited by vaccination or infection, showed any breadth. Finally, SOSIP immunization elicited antibodies against the base of the trimer, while infection did not, consistent with the base being placed onto the virus membrane in the latter setting. Together these data provide new insights into the antibody response against BG505 Env during infection and immunization and limitations that need to be overcome to induce better responses after vaccination.

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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 following Long-Term Vaccination with HIV-1 Env gp140 in Guinea Pigs

Journal of Virology ◽

10.1128/jvi.00369-18 ◽

2018 ◽

Vol 92 (13) ◽

pp. e00369-18 ◽

Cited By ~ 7

Author(s):

Christine A. Bricault ◽

James M. Kovacs ◽

Alexander Badamchi-Zadeh ◽

Krisha McKee ◽

Jennifer L. Shields ◽

...

Keyword(s):

Guinea Pigs ◽

Neutralizing Antibodies ◽

Antibody Responses ◽

Tier 2 ◽

Broadly Neutralizing Antibodies ◽

Vaccination Regimen ◽

Tier 1 ◽

Clade C ◽

Hiv 1

ABSTRACTA vaccination regimen capable of eliciting potent and broadly neutralizing antibodies (bNAbs) remains an unachieved goal of the HIV-1 vaccine field. Here, we report the immunogenicity of longitudinal prime/boost vaccination regimens with a panel of HIV-1 envelope (Env) gp140 protein immunogens over a period of 200 weeks in guinea pigs. We assessed vaccine regimens that included a monovalent clade C gp140 (C97ZA012 [C97]), a tetravalent regimen consisting of four clade C gp140s (C97ZA012, 459C, 405C, and 939C [4C]), and a tetravalent regimen consisting of clade A, B, C, and mosaic gp140s (92UG037, PVO.4, C97ZA012, and Mosaic 3.1, respectively [ABCM]). We found that the 4C and ABCM prime/boost regimens were capable of eliciting greater magnitude and breadth of binding antibody responses targeting variable loop 2 (V2) over time than the monovalent C97-only regimen. The longitudinal boosting regimen conducted over more than 2 years increased the magnitude of certain tier 1 NAb responses but did not increase the magnitude or breadth of heterologous tier 2 NAb responses. These data suggest that additional immunogen design strategies are needed to induce broad, high-titer tier 2 NAb responses.IMPORTANCEThe elicitation of potent, broadly neutralizing antibodies (bNAbs) remains an elusive goal for the HIV-1 vaccine field. In this study, we explored the use of a long-term vaccination regimen with different immunogens to determine if we could elicit bNAbs in guinea pigs. We found that longitudinal boosting over more than 2 years increased tier 1 NAb responses but did not increase the magnitude and breadth of tier 2 NAb responses. These data suggest that additional immunogen designs and vaccination strategies will be necessary to induce broad tier 2 NAb responses.

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Closing and Opening Holes in the Glycan Shield of HIV-1 Envelope Glycoprotein SOSIP Trimers Can Redirect the Neutralizing Antibody Response to the Newly Unmasked Epitopes

Journal of Virology ◽

10.1128/jvi.01656-18 ◽

2018 ◽

Vol 93 (4) ◽

Cited By ~ 12

Author(s):

Rajesh P. Ringe ◽

Pavel Pugach ◽

Christopher A. Cottrell ◽

Celia C. LaBranche ◽

Gemma E. Seabright ◽

...

Keyword(s):

Antibody Response ◽

Viral Entry ◽

Envelope Glycoprotein ◽

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Tier 2 ◽

Protein Surfaces ◽

Opening And Closing ◽

Glycan Site ◽

Hiv 1

ABSTRACTIn HIV-1 vaccine research, native-like, soluble envelope glycoprotein SOSIP trimers are widely used for immunizing animals. The epitopes of autologous neutralizing antibodies (NAbs) induced by the BG505 and B41 SOSIP trimers in rabbits and macaques have been mapped to a few holes in the glycan shields that cover most of the protein surfaces. For BG505 trimers, the dominant autologous NAb epitope in rabbits involves residues that line a cavity caused by the absence of a glycan at residue 241. Here, we blocked this epitope in BG505 SOSIPv4.1 trimer immunogens by knocking in an N-linked glycan at residue 241. We then opened holes elsewhere on the trimer by knocking out single N-linked glycans at residues 197, 234, 276, 332, and 355 and found that NAb responses induced by the 241-glycan-bearing BG505 trimers were frequently redirected to the newly opened sites. The strongest evidence for redirection of the NAb response to neoepitopes, through the opening and closing of glycan holes, was obtained from trimer immunogen groups with the highest occupancy of the N241 site. We also attempted to knock in the N289-glycan to block the sole autologous NAb epitope on the B41 SOSIP.v4.1 trimer. Although a retrospective analysis showed that the new N289-glycan site was substantially underoccupied, we found some evidence for redirection of the NAb response to a neoepitope when this site was knocked in and the N356-glycan site knocked out. In neither study, however, was redirection associated with increased neutralization of heterologous tier 2 viruses.IMPORTANCEEngineered SOSIP trimers mimic envelope-glycoprotein spikes, which stud the surface of HIV-1 particles and mediate viral entry into cells. When used for immunizing test animals, they elicit antibodies that neutralize resistant sequence-matched HIV-1 isolates. These neutralizing antibodies recognize epitopes in holes in the glycan shield that covers the trimer. Here, we added glycans to block the most immunogenic neutralization epitopes on BG505 and B41 SOSIP trimers. In addition, we removed selected other glycans to open new holes that might expose new immunogenic epitopes. We immunized rabbits with the various glycan-modified trimers and then dissected the specificities of the antibody responses. Thus, in principle, the antibody response might be diverted from one site to a more cross-reactive one, which would help in the induction of broadly neutralizing antibodies by HIV-1 vaccines based on envelope glycoproteins.

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A site of vulnerability at V3 crown defined by HIV-1 bNAb M4008_N1

Nature Communications ◽

10.1038/s41467-021-26846-z ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Kun-Wei Chan ◽

Christina C. Luo ◽

Hong Lu ◽

Xueling Wu ◽

Xiang-Peng Kong

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Design ◽

Tier 2 ◽

Broadly Neutralizing Antibodies ◽

Closed Conformation ◽

Immunogen Design ◽

A Site ◽

Β Sheet ◽

Hiv 1

AbstractIdentification of vulnerable sites defined by broadly neutralizing antibodies (bNAbs) on HIV-1 envelope (Env) is crucial for vaccine design, and we present here a vulnerable site defined by bNAb M4008_N1, which neutralizes about 40% of a tier-2 virus panel. A 3.2 Å resolution cryo-EM structure of M4008_N1 in complex with BG505 DS-SOSIP reveals a large, shallow protein epitope surface centered at the V3 crown of gp120 and surrounded by key glycans. M4008_N1 interacts with gp120 primarily through its hammerhead CDR H3 to form a β-sheet interaction with the V3 crown hairpin. This makes M4008_N1 compatible with the closed conformation of the prefusion Env trimer, and thus distinct from other known V3 crown mAbs. This mode of bNAb approaching the immunogenic V3 crown in the native Env trimer suggests a strategy for immunogen design targeting this site of vulnerability.

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Biochemical and Immunogenic Characterization of Soluble Human Immunodeficiency Virus Type 1 Envelope Glycoprotein Trimers Expressed by Semliki Forest Virus

Journal of Virology ◽

10.1128/jvi.79.17.10902-10914.2005 ◽

2005 ◽

Vol 79 (17) ◽

pp. 10902-10914 ◽

Cited By ~ 31

Author(s):

Mattias N. E. Forsell ◽

Yuxing Li ◽

Maria Sundbäck ◽

Krisha Svehla ◽

Peter Liljeström ◽

...

Keyword(s):

Human Immunodeficiency Virus ◽

Immune Responses ◽

Envelope Glycoprotein ◽

Neutralizing Antibodies ◽

Semliki Forest Virus ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Immunodeficiency Virus ◽

Hiv 1

ABSTRACT The current lack of envelope glycoprotein immunogens that elicit broadly neutralizing antibody responses remains a major challenge for human immunodeficiency virus type 1 (HIV-1) vaccine development. However, the recent design and construction of stable soluble gp140 trimers have shown that some neutralization breadth can be achieved by using immunogens that better mimic the functional viral spike complex. The use of genetic delivery systems to drive the in vivo expression of such immunogens for the stimulation of neutralizing antibodies against HIV-1 may offer advantages by maintaining the quaternary structure of the trimeric envelope glycoproteins. Here, we describe the biochemical and immunogenic properties of soluble HIV-1 envelope glycoprotein trimers expressed by recombinant Semliki Forest virus (rSFV). The results presented here demonstrate that rSFV supports the expression of stable soluble gp140 trimers that retain recognition by conformationally sensitive antibodies. Further, we show that rSFV particle immunizations efficiently primed immune responses as measured after a single boost with purified trimeric gp140 protein, resulting in a Th1-biased antibody response. This differed from the Th2-biased antibody response obtained after repeated immunizations with purified gp140 protein trimers. Despite this difference, both regimens stimulated neutralizing antibody responses of similar potency. This suggests that rSFV may be a useful component of a viral vector prime-protein boost regimen aimed at stimulating both cell-mediated immune responses and neutralizing antibodies against HIV-1.

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HIV-1 vaccine design through minimizing envelope metastability

10.1101/361931 ◽

2018 ◽

Author(s):

Linling He ◽

Sonu Kumar ◽

Joel D. Allen ◽

Deli Huang ◽

Xiaohe Lin ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Statistical Significance ◽

Vaccine Design ◽

Neutralizing Antibody ◽

High Yield ◽

List Type ◽

Tier 2 ◽

Vaccine Strategy ◽

Antibody Recognition ◽

Hiv 1

SUMMARYOvercoming envelope metastability is crucial to trimer-based HIV-1 vaccine design. Here, we present a coherent vaccine strategy by minimizing metastability. For ten strains across five clades, we demonstrate that gp41 ectodomain (gp41ECTO) is the main source of envelope metastability by replacing wild-type gp41ECTOwith BG505 gp41ECTOof the uncleaved prefusion-optimized (UFO) design. These gp41ECTO-swapped trimers can be produced in CHO cells with high yield and high purity. Crystal structure of a gp41ECTO-swapped trimer elucidates how a neutralization-resistant tier 3 virus evades antibody recognition of the V2 apex. UFO trimers of transmitted/founder (T/F) viruses and UFO trimers containing a consensus-based ancestral gp41ECTOsuggest an evolutionary root of the metastability. Gp41ECTO-stabilized trimers can be readily displayed on 24- and 60-meric nanoparticles, with incorporation of additional T cell help illustrated for a hyperstable 60-mer. In mice and rabbits, gp140 nanoparticles induced more effective tier 2 neutralizing antibody response than trimers with statistical significance.HIGHLIGHTSgp41 is the main source of HIV-1 envelope metastabilityBG505 gp41 of the UFO design stabilizes gp140 trimers of diverse subtypesgp41 stabilization facilitates gp140 nanoparticle assembly and improves productionNanoparticles elicit tier 2 neutralizing antibodies more effectively than trimers

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