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Velázquez-Moctezuma R, Augestad EH, Castelli M, Holmboe Olesen C, Clementi N, Clementi M, Mancini N, Prentoe J. Mechanisms of Hepatitis C Virus Escape from Vaccine-Relevant Neutralizing Antibodies. Vaccines (Basel) 2021; 9:291. [PMID: 33804732 PMCID: PMC8004074 DOI: 10.3390/vaccines9030291] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/15/2022] Open
Abstract
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.
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Affiliation(s)
- Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Elias H. Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Christina Holmboe Olesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
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Shimizu YK, Hijikata M, Oshima M, Shimizu K, Alter HJ, Purcell RH, Yoshikura H, Hotta H. Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PLoS One 2013; 8:e55874. [PMID: 23409074 PMCID: PMC3567033 DOI: 10.1371/journal.pone.0055874] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/03/2013] [Indexed: 11/18/2022] Open
Abstract
We isolated and characterized two human monoclonal antibodies to the envelope E2 protein of hepatitis C virus (HCV). Lymphoblastoid cell lines stably producing antibodies were obtained by immortalizing peripheral blood mononuclear cells of a patient with chronic hepatitis C using Epstein-Barr virus. Screening for antibody-positive clones was carried out by immunofluorescence with Huh7 cells expressing the E2 protein of HCV strain H (genotype 1a) isolated from the same patient. Isotype of resulting antibodies, #37 and #55, was IgG1/kappa and IgG1/lambda, respectively. Epitope mapping revealed that #37 and #55 recognize conformational epitopes spanning amino acids 429 to 652 and 508 to 607, respectively. By immunofluorescence using virus-infected Huh7.5 cells as targets both antibodies were reactive with all of the nine different HCV genotypes/subtypes tested. The antibodies showed a different pattern of immuno-staining; while #37 gave granular reactions mostly located in the periphery of the nucleus, #55 gave diffuse staining throughout the cytoplasm. Both antibodies were shown by immuno-gold electron microscopy to bind to intact viral particles. In a neutralization assay (focus-forming unit reduction using chimeric infectious HCV containing structural proteins derived from genotypes 1a, 1b, 2a, 2b, 3a, 4a, 5a, 6a, and 7a), #55 inhibited the infection of all HCV genotypes tested but genotype 7a to a lesser extent. #37 did not neutralize any of these viruses. As a broadly cross-neutralizing human antibody, #55 may be useful for passive immunotherapy of HCV infection.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Blocking/immunology
- Antibodies, Blocking/metabolism
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing
- Antibodies, Viral/chemistry
- Antibodies, Viral/genetics
- Antibodies, Viral/immunology
- Antibody Affinity/immunology
- Antigens, Viral/chemistry
- Antigens, Viral/immunology
- Antigens, Viral/metabolism
- Cell Line, Transformed
- Cross Reactions/immunology
- Epitope Mapping
- Epitopes/chemistry
- Epitopes/immunology
- Genotype
- Hepacivirus/genetics
- Hepacivirus/immunology
- Humans
- Immunoglobulin G/chemistry
- Immunoglobulin G/genetics
- Immunoglobulin G/immunology
- Immunoglobulin Heavy Chains/chemistry
- Immunoglobulin Heavy Chains/genetics
- Lymphocytes/immunology
- Lymphocytes/metabolism
- Molecular Sequence Data
- Neutralization Tests
- Protein Transport
- Sequence Alignment
- Viral Envelope Proteins/immunology
- Viral Envelope Proteins/metabolism
- Virion/immunology
- Virion/ultrastructure
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Affiliation(s)
- Yohko K Shimizu
- Division of Microbiology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
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