scholarly journals Hepatitis C Virus Vaccine Research: Time to Put Up or Shut Up

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1596
Author(s):  
Alex S. Hartlage ◽  
Amit Kapoor
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Protective Immunity ◽  
Vaccine Development ◽  
Human Infection ◽  
Infection Model ◽  
Vaccine Trials ◽  
Viral Vaccine ◽  
Chronic Hcv

Unless urgently needed to prevent a pandemic, the development of a viral vaccine should follow a rigorous scientific approach. Each vaccine candidate should be designed considering the in-depth knowledge of protective immunity, followed by preclinical studies to assess immunogenicity and safety, and lastly, the evaluation of selected vaccines in human clinical trials. The recently concluded first phase II clinical trial of a human hepatitis C virus (HCV) vaccine followed this approach. Still, despite promising preclinical results, it failed to protect against chronic infection, raising grave concerns about our understanding of protective immunity. This setback, combined with the lack of HCV animal models and availability of new highly effective antivirals, has fueled ongoing discussions of using a controlled human infection model (CHIM) to test new HCV vaccine candidates. Before taking on such an approach, however, we must carefully weigh all the ethical and health consequences of human infection in the absence of a complete understanding of HCV immunity and pathogenesis. We know that there are significant gaps in our knowledge of adaptive immunity necessary to prevent chronic HCV infection. This review discusses our current understanding of HCV immunity and the critical gaps that should be filled before embarking upon new HCV vaccine trials. We discuss the importance of T cells, neutralizing antibodies, and HCV genetic diversity. We address if and how the animal HCV-like viruses can be used for conceptualizing effective HCV vaccines and what we have learned so far from these HCV surrogates. Finally, we propose a logical but narrow path forward for HCV vaccine development.

scholarly journals Convergent antibody responses associated with broad neutralization of hepatitis C virus and clearance of infection

2021 ◽  
Author(s):  
Nicole E. Skinner ◽  
Clinton O. Ogega ◽  
Nicole Frumento ◽  
Kaitlyn E. Clark ◽  
Srinivasan Yegnasubramanian ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Early Development ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
High Plasma ◽  
Spontaneous Clearance ◽  
Cell Repertoire ◽  
Molecular Features

AbstractEarly development of broadly neutralizing antibodies (bNAbs) targeting the hepatitis C virus (HCV) envelope glycoprotein E2 is associated with spontaneous clearance of infection, so induction of bNAbs is a major goal of HCV vaccine development. However, much remains to be learned at a molecular level about protective E2-reactive antibodies, since HCV infection persists in some individuals despite early development of broadly neutralizing plasma. To examine B cell repertoire features associated with broad neutralization and viral clearance, we performed RNA sequencing of the B cell receptors (BCRs) of HCV E2-reactive B cells of people with cleared or persistent HCV, including subjects with high or low plasma neutralizing breadth in both clearance and persistence groups. We identified many E2-reactive public BCR clonotypes, which are antibody clones with the same V and J-genes and identical CDR3 sequences, shared among subjects grouped by either clearance or neutralization status. The majority (89) of these public clonotypes were shared by two subjects with broad plasma neutralizing activity and cleared infection, but not found in subjects with high plasma neutralizing breadth and persistent infection. We cloned a potent, cross-reactive neutralizing monoclonal antibody (mAb) by pairing the most abundant public heavy and light chains from these two subjects, providing evidence that broadly E2-reactive public clonotypes arise in a subset of individuals with broadly neutralizing plasma and spontaneous clearance of infection. Further characterization of the molecular features and function of these antibodies can inform HCV vaccine development.

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.

scholarly journals Detection of neutralizing antibodies to hepatitis C virus using a biliary cell infection model

2002 ◽  
Vol 83 (7) ◽  
pp. 1673-1678 ◽  
Author(s):  
Saadia Bichr ◽  
Rosanna Rende-Fournier ◽  
Giovanna Vona ◽  
Ana-Maria Yamamoto ◽  
Erik Depla ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Core Protein ◽  
Present Report ◽  
Infection Model ◽  
Target Cells ◽  
Cell Infection ◽  
Hcv Core Protein

The identification and characterization of neutralizing anti-hepatitis C virus (HCV) antibodies may have a major impact on understanding HCV pathogenesis. However, to date, their detection has only been based on the inhibition of either the E2 envelope protein or HCV virions binding to different target cells. The permissivity of primary biliary cells for HCV infection has been demonstrated previously. In the present report, infection of biliary cells was demonstrated further by combining PCR and immunohistochemical detection of the HCV core protein. This study demonstrates, using both serum and purified IgG, the presence of neutralizing anti-HCV antibodies in the serum of patients showing long-term response to antiviral therapy. Overall, the usefulness of the primary biliary cell infection model to investigate anti-HCV neutralization is shown.

scholarly journals Broad Anti-Hepatitis C Virus (HCV) Antibody Responses Are Associated with Improved Clinical Disease Parameters in Chronic HCV Infection

2016 ◽  
Vol 90 (9) ◽  
pp. 4530-4543 ◽  
Author(s):  
Rachael E. Swann ◽  
Vanessa M. Cowton ◽  
Mark W. Robinson ◽  
Sarah J. Cole ◽  
Stephen T. Barclay ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Chronic Infection ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Hcv Infection ◽  
Neutralization Activity ◽  
Broadly Neutralizing Antibody ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

ABSTRACTDuring hepatitis C virus (HCV) infection, broadly neutralizing antibody (bNAb) responses targeting E1E2 envelope glycoproteins are generated in many individuals. It is unclear if these antibodies play a protective or a pathogenic role during chronic infection. In this study, we investigated whether bNAb responses in individuals with chronic infection were associated with differences in clinical presentation. Patient-derived purified serum IgG was used to assess the breadth of HCV E1E2 binding and the neutralization activity of HCV pseudoparticles. The binding and neutralization activity results for two panels bearing viral envelope proteins representing either an intergenotype or an intragenotype 1 group were compared. We found that the HCV load was negatively associated with strong cross-genotypic E1E2 binding (P= 0.03). Overall, we observed only a modest correlation between total E1E2 binding and neutralization ability. The breadth of intergenotype neutralization did not correlate with any clinical parameters; however, analysis of individuals with genotype 1 (gt1) HCV infection (n= 20), using an intragenotype pseudoparticle panel, found a strong association between neutralization breadth and reduced liver fibrosis (P= 0.006). A broad bNAb response in our cohort with chronic infection was associated with a single nucleotide polymorphism (SNP) in theHLA-DQB1gene (P= 0.038), as previously reported in a cohort with acute disease. Furthermore, the bNAbs in these individuals targeted more than one region of E2-neutralizing epitopes, as assessed through cross-competition of patient bNAbs with well-characterized E2 antibodies. We conclude that the bNAb responses in patients with chronic gt1 infection are associated with lower rates of fibrosis and host genetics may play a role in the ability to raise such responses.IMPORTANCEGlobally, there are 130 million to 150 million people with chronic HCV infection. Typically, the disease is progressive and is a major cause of severe liver cirrhosis and hepatocellular carcinoma. While it is known that neutralizing antibodies have a role in spontaneous clearance during acute infection, little is known about their role in chronic infection. In the present work, we investigated the antibody response in a cohort of chronically infected individuals and found that a broadly neutralizing antibody response is protective and is associated with reduced levels of liver fibrosis and cirrhosis. We also found an association between SNPs in class II HLA genes and the presence of a broadly neutralizing response, indicating that antigen presentation may be important for the production of HCV-neutralizing antibodies.

scholarly journals Intrahepatic Genetic Inoculation of Hepatitis C Virus RNA Confers Cross-Protective Immunity

2001 ◽  
Vol 75 (15) ◽  
pp. 7142-7148 ◽  
Author(s):  
Amy J. Weiner ◽  
Xavier Paliard ◽  
Mark J. Selby ◽  
Angelica Medina-Selby ◽  
Doris Coit ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protective Immunity ◽  
Hcv Infection ◽  
Hcv Rna ◽  
Genetic Immunization ◽  
Virus Rna ◽  
Cast Doubt ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

ABSTRACT Naturally occurring hepatitis C virus (HCV) infection has long been thought to induce a weak immunity which is insufficient to protect an individual from subsequent infections and has cast doubt on the ability to develop effective vaccines. A series of intrahepatic genetic inoculations (IHGI) with type 1a HCV RNA were performed in a chimpanzee to determine whether a form of genetic immunization might stimulate protective immunity. We demonstrate that the chimpanzee not only developed protective immunity to the homologous type 1a RNA after rechallenge by IHGI but was also protected from chronic HCV infection after sequential rechallenge with 100 50% chimpanzee infectious doses of a heterologous type 1a (H77) and 1b (HC-J4) whole-virus inoculum. These results offer encouragement to pursue the development of HCV vaccines.

scholarly journals A Hepatitis C Virus Envelope Polymorphism Confers Resistance to Neutralization by Polyclonal Sera and Broadly Neutralizing Monoclonal Antibodies

2016 ◽  
Vol 90 (7) ◽  
pp. 3773-3782 ◽  
Author(s):  
Lisa N. Wasilewski ◽  
Ramy El-Diwany ◽  
Supriya Munshaw ◽  
Anna E. Snider ◽  
Jillian K. Brady ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Monoclonal Antibodies ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Resistance Mutation ◽  
The United States ◽  
Broadly Neutralizing Antibodies ◽  
Access To Treatment

ABSTRACTHepatitis C virus (HCV) infection is a global health problem, with millions of chronically infected individuals at risk for cirrhosis and hepatocellular carcinoma. HCV vaccine development is vital in the effort toward disease control and eradication, an undertaking aided by an increased understanding of the mechanisms of resistance to broadly neutralizing antibodies (bNAbs). In this study, we identified HCV codons that vary deep in a phylogenetic tree of HCV sequences and showed that a polymorphism at one of these positions renders Bole1a, a computationally derived, ancestral genotype 1a HCV strain, resistant to neutralization by both polyclonal-HCV-infected plasma and multiple broadly neutralizing monoclonal antibodies with unique binding epitopes. This bNAb resistance mutation reduces replicative fitness, which may explain the persistence of both neutralization-sensitive and neutralization-resistant variants in circulating viral strains. This work identifies an important determinant of bNAb resistance in an ancestral, representative HCV genome, which may inform HCV vaccine development.IMPORTANCEWorldwide, more than 170 million people are infected with hepatitis C virus (HCV), the leading cause of hepatocellular carcinoma and liver transplantation in the United States. Despite recent significant advances in HCV treatment, a vaccine is needed. Control of the HCV pandemic with drug treatment alone is likely to fail due to limited access to treatment, reinfections in high-risk individuals, and the potential for resistance to direct-acting antivirals (DAAs). Broadly neutralizing antibodies (bNAbs) block infection by diverse HCV variants and therefore serve as a useful guide for vaccine development, but our understanding of resistance to bNAbs is incomplete. In this report, we identify a viral polymorphism conferring resistance to neutralization by both polyclonal plasma and broadly neutralizing monoclonal antibodies, which may inform HCV vaccine development.

scholarly journals Ethical and Practical Issues Associated With the Possibility of Using Controlled Human Infection Trials in Developing a Hepatitis C Virus Vaccine

2020 ◽  
Vol 71 (11) ◽  
pp. 2986-2990 ◽  
Author(s):  
Andrea Cox ◽  
Mark Sulkowski ◽  
Jeremy Sugarman
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Vaccine ◽  
Vaccine Development ◽  
Effective Means ◽  
Human Infection ◽  
Morbidity And Mortality ◽  
Risk Of Infection ◽  
Potential Approach

Abstract Despite the existence of established treatments for hepatitis C virus (HCV), more effective means of preventing infection, such as a vaccine, are arguably needed to help reduce substantial global morbidity and mortality. Given the expected challenges of developing such a vaccine among those at heightened risk of infection, controlled human infection studies seem to be a promising potential approach to HCV vaccine development, but they raise substantial ethical and practical concerns. In this article, we describe some of the challenges related to the possibility of using controlled human infection studies to accelerate HCV vaccine development. The related ethical and practical concerns require further deliberation before such studies are planned and implemented.

scholarly journals Proof of concept for rational design of hepatitis C virus E2 core nanoparticle vaccines

2020 ◽  
Vol 6 (16) ◽  
pp. eaaz6225 ◽  
Author(s):  
Linling He ◽  
Netanel Tzarum ◽  
Xiaohe Lin ◽  
Benjamin Shapero ◽  
Cindy Sou ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Rational Design ◽  
Vaccine Development ◽  
Variable Region ◽  
Improved Stability ◽  
Cell Patterns ◽  
Neutralizing Epitopes

Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are responsible for cell entry, with E2 being the major target of neutralizing antibodies (NAbs). Here, we present a comprehensive strategy for B cell–based HCV vaccine development through E2 optimization and nanoparticle display. We redesigned variable region 2 in a truncated form (tVR2) on E2 cores derived from genotypes 1a and 6a, resulting in improved stability and antigenicity. Crystal structures of three optimized E2 cores with human cross-genotype NAbs (AR3s) revealed how the modified tVR2 stabilizes E2 without altering key neutralizing epitopes. We then displayed these E2 cores on 24- and 60-meric nanoparticles and achieved substantial yield and purity, as well as enhanced antigenicity. In mice, these nanoparticles elicited more effective NAb responses than soluble E2 cores. Next-generation sequencing (NGS) defined distinct B cell patterns associated with nanoparticle-induced antibody responses, which target the conserved neutralizing epitopes on E2 and cross-neutralize HCV genotypes.

scholarly journals Mechanisms of Hepatitis C Virus Escape from Vaccine-Relevant Neutralizing Antibodies

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 291
Author(s):  
Rodrigo Velázquez-Moctezuma ◽  
Elias H. Augestad ◽  
Matteo Castelli ◽  
Christina Holmboe Olesen ◽  
Nicola Clementi ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
B Cell ◽  
Neutralizing Antibodies ◽  
Cell Vaccine ◽  
Special Focus ◽  
Direct Modification ◽  
Chronic Hcv

Hepatitis C virus (HCV) is a major causative agent of acute and chronic hepatitis. It is estimated that 400,000 people die every year from chronic HCV infection, mostly from severe liver-related diseases such as cirrhosis and liver cancer. Although HCV was discovered more than 30 years ago, an efficient prophylactic vaccine is still missing. The HCV glycoprotein complex, E1/E2, is the principal target of neutralizing antibodies (NAbs) and, thus, is an attractive antigen for B-cell vaccine design. However, the high genetic variability of the virus necessitates the identification of conserved epitopes. Moreover, the high intrinsic mutational capacity of HCV allows the virus to continually escape broadly NAbs (bNAbs), which is likely to cause issues with vaccine-resistant variants. Several studies have assessed the barrier-to-resistance of vaccine-relevant bNAbs in vivo and in vitro. Interestingly, recent studies have suggested that escape substitutions can confer antibody resistance not only by direct modification of the epitope but indirectly through allosteric effects, which can be grouped based on the breadth of these effects on antibody susceptibility. In this review, we summarize the current understanding of HCV-specific NAbs, with a special focus on vaccine-relevant bNAbs and their targets. We highlight antibody escape studies pointing out the different methodologies and the escape mutations identified thus far. Finally, we analyze the antibody escape mechanisms of envelope protein escape substitutions and polymorphisms according to the most recent evidence in the HCV field. The accumulated knowledge in identifying bNAb epitopes as well as assessing barriers to resistance and elucidating relevant escape mechanisms may prove critical in the successful development of an HCV B-cell vaccine.

scholarly journals Where to Next? Research Directions after the First Hepatitis C Vaccine Efficacy Trial

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1351
Author(s):  
Christopher C. Phelps ◽  
Christopher M. Walker ◽  
Jonathan R. Honegger
Keyword(s):  
Hepatitis C ◽  
Vaccine Efficacy ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Effective Vaccine ◽  
Published Data ◽  
Efficacy Trial ◽  
Vaccine Platform ◽  
Research Directions ◽  
Chronic Hcv

Thirty years after its discovery, the hepatitis C virus (HCV) remains a leading cause of liver disease worldwide. Given that many countries continue to experience high rates of transmission despite the availability of potent antiviral therapies, an effective vaccine is seen as critical for the elimination of HCV. The recent failure of the first vaccine efficacy trial for the prevention of chronic HCV confirmed suspicions that this virus will be a challenging vaccine target. Here, we examine the published data from this first efficacy trial along with the earlier clinical and pre-clinical studies of the vaccine candidate and then discuss three key research directions expected to be important in ongoing and future HCV vaccine development. These include the following: 1. design of novel immunogens that generate immune responses to genetically diverse HCV genotypes and subtypes, 2. strategies to elicit broadly neutralizing antibodies against envelope glycoproteins in addition to cytotoxic and helper T cell responses, and 3. consideration of the unique immunological status of individuals most at risk for HCV infection, including those who inject drugs, in vaccine platform development and early immunogenicity trials.

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