scholarly journals Virus-Like Particles Containing the E2 Core Domain of Hepatitis C Virus Generate Broadly Neutralizing Antibodies in Guinea Pigs.

2022 ◽  
Author(s):  
Joey McGregor ◽  
Joshua M. Hardy ◽  
Chan-Sien Lay ◽  
Irene Boo ◽  
Michael Piontek ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Guinea Pigs ◽  
Neutralizing Antibodies ◽  
Large Scale ◽  
Broadly Neutralizing Antibodies ◽  
Virus Like Particles ◽  
Duck Hepatitis ◽  
B Virus ◽  
Glycoprotein E2

A vaccine to prevent hepatitis C virus (HCV) infection is urgently needed for use alongside direct acting antiviral drugs to achieve elimination targets. We have previously shown that a soluble recombinant form of the glycoprotein E2 ectodomain (residues 384-661), that lacks three variable regions (Δ123) is able to elicit a higher titer of broadly neutralizing antibodies (bnAbs) in comparison to the parental form (receptor-binding domain; RBD). In this study, we engineered a viral nanoparticle that displays HCV glycoprotein E2 on a duck hepatitis B virus (DHBV) small surface antigen (S) scaffold. Four variants of E2-S virus-like particles (VLPs) were constructed: Δ123-S and RBD-S, and Δ123A7-S and RBDA7-S in which 7 cysteines were replaced with alanines. While all four E2-S VLPs display E2 as a surface antigen, the Δ123A7-S and RBDA7-S VLPs were the most efficiently secreted from transfected mammalian cells, and displayed epitopes recognized by cross-genotype broadly neutralizing monoclonal antibodies (bnmAbs). Both Δ123A7-S and RBDA7-S VLPs were immunogenic in guinea pigs, generating high titers of antibodies reactive to native E2 and able to prevent the interaction between E2 and the cellular receptor CD81. Four out of eight animals immunized with Δ123A7-S elicited neutralizing antibodies (nAbs), with three of those animals generating bnAbs against 7 genotypes. Immune serum generated by animals with nAbs mapped to major neutralization epitopes located at residues 412-420 (epitope I) and antigenic region 3. VLPs that display E2 glycoproteins represent a promising vaccine platform for HCV and could be adapted to large-scale manufacturing in yeast systems. IMPORTANCE There is currently no vaccine to prevent hepatitis C virus infection, which affects more than 71 million people globally and is a leading cause of progressive liver disease including cirrhosis and cancer. Broadly neutralizing antibodies that recognise the E2 envelope glycoprotein can protect against heterologous viral infection and correlate with viral clearance in humans. However, broadly neutralizing antibodies are difficult to generate due to conformational flexibility of the E2 protein and epitope occlusion. Here we show that a VLP vaccine using the duck hepatitis B virus S antigen fused to HCV glycoprotein E2 assembles into virus like particles that display epitopes recognised by broadly neutralizing antibodies and elicit such antibodies in guinea pigs. This platform represents a novel HCV vaccine candidate amenable to large-scale manufacture at low cost.

scholarly journals The core domain of hepatitis C virus glycoprotein E2 generates potent cross-neutralizing antibodies in guinea pigs

Hepatology ◽  
2017 ◽  
Vol 65 (4) ◽  
pp. 1117-1131 ◽  
Author(s):  
Patricia T. Vietheer ◽  
Irene Boo ◽  
Jun Gu ◽  
Kathleen McCaffrey ◽  
Stirling Edwards ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Guinea Pigs ◽  
Neutralizing Antibodies ◽  
Core Domain ◽  
Virus Glycoprotein ◽  
The Core ◽  
Glycoprotein E2

scholarly journals Specific Antibodies Induced by Immunization with Hepatitis B Virus-Like Particles Carrying Hepatitis C Virus Envelope Glycoprotein 2 Epitopes Show Differential Neutralization Efficiency

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 294
Author(s):  
Anna Czarnota ◽  
Anna Offersgaard ◽  
Anne Finne Pihl ◽  
Jannick Prentoe ◽  
Jens Bukh ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hepatitis B Virus ◽  
Hepatitis B ◽  
Neutralizing Antibodies ◽  
Expression System ◽  
Small Surface ◽  
Major Health Problem ◽  
Virus Like Particles ◽  
B Virus

Hepatitis C virus (HCV) infection with associated chronic liver diseases is a major health problem worldwide. Here, we designed hepatitis B virus (HBV) small surface antigen (sHBsAg) virus-like particles (VLPs) presenting different epitopes derived from the HCV E2 glycoprotein (residues 412–425, 434–446, 502–520, and 523–535 of isolate H77C). Epitopes were selected based on their amino acid sequence conservation and were previously reported as targets of HCV neutralizing antibodies. Chimeric VLPs obtained in the Leishmania tarentolae expression system, in combination with the adjuvant Addavax, were used to immunize mice. Although all VLPs induced strong humoral responses, only antibodies directed against HCV 412–425 and 523–535 epitopes were able to react with the native E1E2 glycoprotein complexes of different HCV genotypes in ELISA. Neutralization assays against genotype 1–6 cell culture infectious HCV (HCVcc), revealed that only VLPs carrying the 412–425 epitope induced efficient HCV cross-neutralizing antibodies, but with isolate specific variations in efficacy that could not necessarily be explained by differences in epitope sequences. In contrast, antibodies targeting 434–446, 502–520, and 523–535 epitopes were not neutralizing HCVcc, highlighting the importance of conformational antibodies for efficient virus neutralization. Thus, 412–425 remains the most promising linear E2 epitope for further bivalent, rationally designed vaccine research.

scholarly journals Plasma deconvolution identifies broadly neutralizing antibodies associated with hepatitis C virus clearance

2019 ◽  
Vol 129 (11) ◽  
pp. 4786-4796 ◽  
Author(s):  
Valerie J. Kinchen ◽  
Guido Massaccesi ◽  
Andrew I. Flyak ◽  
Madeleine C. Mankowski ◽  
Michelle D. Colbert ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies ◽  
Virus Clearance

scholarly journals Broadly neutralizing antibodies with few somatic mutations and hepatitis C virus clearance

JCI Insight ◽  
2017 ◽  
Vol 2 (9) ◽  
Author(s):  
Justin R. Bailey ◽  
Andrew I. Flyak ◽  
Valerie J. Cohen ◽  
Hui Li ◽  
Lisa N. Wasilewski ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Somatic Mutations ◽  
Broadly Neutralizing Antibodies ◽  
Virus Clearance

scholarly journals Structural Flexibility of a Conserved Antigenic Region in Hepatitis C Virus Glycoprotein E2 Recognized by Broadly Neutralizing Antibodies

2014 ◽  
Vol 89 (4) ◽  
pp. 2170-2181 ◽  
Author(s):  
Annalisa Meola ◽  
Alexander W. Tarr ◽  
Patrick England ◽  
Luke W. Meredith ◽  
C. Patrick McClure ◽  
...  
Keyword(s):  
Amino Acids ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Conformational Flexibility ◽  
Structural Flexibility ◽  
Viral Spread ◽  
Antigenic Region ◽  
Glycoprotein E2

ABSTRACTNeutralizing antibodies (NAbs) targeting glycoprotein E2 are important for the control of hepatitis C virus (HCV) infection. One conserved antigenic site (amino acids 412 to 423) is disordered in the reported E2 structure, but a synthetic peptide mimicking this site forms a β-hairpin in complex with three independent NAbs. Our structure of the same peptide in complex with NAb 3/11 demonstrates a strikingly different extended conformation. We also show that residues 412 to 423 are essential for virus entry but not for E2 folding. Together with the neutralizing capacity of the 3/11 Fab fragment, this indicates an unexpected structural flexibility within this epitope. NAbs 3/11 and AP33 (recognizing the extended and β-hairpin conformations, respectively) display similar neutralizing activities despite converse binding kinetics. Our results suggest that HCV utilizes conformational flexibility as an immune evasion strategy, contributing to the limited immunogenicity of this epitope in patients, similar to the conformational flexibility described for other enveloped and nonenveloped viruses.IMPORTANCEApproximately 180 million people worldwide are infected with hepatitis C virus (HCV), and neutralizing antibodies play an important role in controlling the replication of this major human pathogen. We show here that one of the most conserved antigenic sites within the major glycoprotein E2 (amino acids 412 to 423), which is disordered in the recently reported crystal structure of an E2 core fragment, can adopt different conformations in the context of the infectious virus particle. Recombinant Fab fragments recognizing different conformations of this antigenic site have similar neutralization activities in spite of converse kinetic binding parameters. Of note, an antibody response targeting this antigenic region is less frequent than those targeting other more immunogenic regions in E2. Our results suggest that the observed conformational flexibility in this conserved antigenic region contributes to the evasion of the humoral host immune response, facilitating chronicity and the viral spread of HCV within an infected individual.

Broadly neutralizing antibodies protect against hepatitis C virus quasispecies challenge

2007 ◽  
Vol 14 (1) ◽  
pp. 25-27 ◽  
Author(s):  
Mansun Law ◽  
Toshiaki Maruyama ◽  
Jamie Lewis ◽  
Erick Giang ◽  
Alexander W Tarr ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Broadly Neutralizing Antibodies

scholarly journals Antibody Response to Hypervariable Region 1 Interferes with Broadly Neutralizing Antibodies to Hepatitis C Virus

2016 ◽  
Vol 90 (6) ◽  
pp. 3112-3122 ◽  
Author(s):  
Zhen-yong Keck ◽  
Christine Girard-Blanc ◽  
Wenyan Wang ◽  
Patrick Lau ◽  
Adam Zuiani ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Persistent Infection ◽  
Neutralizing Antibodies ◽  
Hypervariable Region ◽  
Humoral Response ◽  
Broadly Neutralizing Antibodies ◽  
Alanine Scanning Mutagenesis ◽  
Effect Analysis ◽  
Hypervariable Region 1

ABSTRACTHypervariable region 1 (HVR1) (amino acids [aa] 384 to 410) on the E2 glycoprotein of hepatitis C virus contributes to persistent infection by evolving escape mutations that attenuate binding of inhibitory antibodies and by blocking access of broadly neutralizing antibodies to their epitopes. A third proposed mechanism of immune antagonism is that poorly neutralizing antibodies binding to HVR1 interfere with binding of other superior neutralizing antibodies. Epitope mapping of human monoclonal antibodies (HMAbs) that bind to an adjacent, conserved domain on E2 encompassing aa 412 to 423 revealed two subsets, designated HC33 HMAbs. While both subsets have contact residues within aa 412 to 423, alanine-scanning mutagenesis suggested that one subset, which includes HC33.8, has an additional contact residue within HVR1. To test for interference of anti-HVR1 antibodies with binding of antibodies to aa 412 to 423 and other E2 determinants recognized by broadly neutralizing HMAbs, two murine MAbs against HVR1 (H77.16) and aa 412 to 423 (H77.39) were studied. As expected, H77.39 inhibited the binding of all HC33 HMAbs. Unexpectedly, H77.16 also inhibited the binding of both subsets of HC33 HMAbs. This inhibition also was observed against other broadly neutralizing HMAbs to epitopes outside aa 412 to 423. Combination antibody neutralization studies by the median-effect analysis method with H77.16 and broadly reactive HMAbs revealed antagonism between these antibodies. Structural studies demonstrated conformational flexibility in this antigenic region, which supports the possibility of anti-HVR1 antibodies hindering the binding of broadly neutralizing MAbs. These findings support the hypothesis that anti-HVR1 antibodies can interfere with a protective humoral response against HCV infection.IMPORTANCEHVR1 contributes to persistent infection by evolving mutations that escape from neutralizing antibodies to HVR1 and by shielding broadly neutralizing antibodies from their epitopes. This study provides insight into a new immune antagonism mechanism by which the binding of antibodies to HVR1 blocks the binding and activity of broadly neutralizing antibodies to HCV. Immunization strategies that avoid the induction of HVR1 antibodies should increase the inhibitory activity of broadly neutralizing anti-HCV antibodies elicited by candidate vaccines.

scholarly journals Conformational Flexibility in the Immunoglobulin-Like Domain of the Hepatitis C Virus Glycoprotein E2

mBio ◽  
2017 ◽  
Vol 8 (3) ◽  
Author(s):  
Ieva Vasiliauskaite ◽  
Ania Owsianka ◽  
Patrick England ◽  
Abdul Ghafoor Khan ◽  
Sarah Cole ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Binding Site ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Asymptomatic Infection ◽  
Effective Vaccine ◽  
Viral Glycoprotein ◽  
Direct Acting Antiviral ◽  
Glycoprotein E2

ABSTRACT The hepatitis C virus (HCV) glycoprotein E2 is the major target of neutralizing antibodies and is therefore highly relevant for vaccine design. Its structure features a central immunoglobulin (Ig)-like β-sandwich that contributes to the binding site for the cellular receptor CD81. We show that a synthetic peptide corresponding to a β-strand of this Ig-like domain forms an α-helix in complex with the anti-E2 antibody DAO5, demonstrating an inside-out flip of hydrophobic residues and a secondary structure change in the composite CD81 binding site. A detailed interaction analysis of DAO5 and cross-competing neutralizing antibodies with soluble E2 revealed that the Ig-like domain is trapped by different antibodies in at least two distinct conformations. DAO5 specifically captures retrovirus particles bearing HCV glycoproteins (HCVpp) and infectious cell culture-derived HCV particles (HCVcc). Infection of cells by DAO5-captured HCVpp can be blocked by a cross-competing neutralizing antibody, indicating that a single virus particle simultaneously displays E2 molecules in more than one conformation on its surface. Such conformational plasticity of the HCV E2 receptor binding site has important implications for immunogen design. IMPORTANCE Recent advances in the treatment of hepatitis C virus (HCV) infection with direct-acting antiviral drugs have enabled the control of this major human pathogen. However, due to their high costs and limited accessibility in combination with the lack of awareness of the mostly asymptomatic infection, there is an unchanged urgent need for an effective vaccine. The viral glycoprotein E2 contains regions that are crucial for virus entry into the host cell, and antibodies that bind to these regions can neutralize infection. One of the major targets of neutralizing antibodies is the central immunoglobulin (Ig)-like domain within E2. We show here that this Ig-like domain is conformationally flexible at the surface of infectious HCV particles and pseudoparticles. Our study provides novel insights into the interactions of HCV E2 with the humoral immune system that should aid future vaccine development. IMPORTANCE Recent advances in the treatment of hepatitis C virus (HCV) infection with direct-acting antiviral drugs have enabled the control of this major human pathogen. However, due to their high costs and limited accessibility in combination with the lack of awareness of the mostly asymptomatic infection, there is an unchanged urgent need for an effective vaccine. The viral glycoprotein E2 contains regions that are crucial for virus entry into the host cell, and antibodies that bind to these regions can neutralize infection. One of the major targets of neutralizing antibodies is the central immunoglobulin (Ig)-like domain within E2. We show here that this Ig-like domain is conformationally flexible at the surface of infectious HCV particles and pseudoparticles. Our study provides novel insights into the interactions of HCV E2 with the humoral immune system that should aid future vaccine development.

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