title: Altered Glycosylation Patterns Increase Immunogenicity of a Subunit Hepatitis C Virus Vaccine, Inducing Neutralizing Antibodies Which Confer Protection in Mice.
abstract: Hepatitis C virus (HCV) infection is a global health problem for which no vaccine is available. HCV has a highly heterogeneous RNA genome and can be classified into seven genotypes. Due to the high genetic and resultant antigenic variation among the genotypes, inducing antibodies capable of neutralizing most of the HCV genotypes by experimental vaccination has been challenging. Previous efforts focused on priming humoral immune responses with recombinant HCV envelope E2 protein produced in mammalian cells. Here, we report that a soluble form of HCV E2 (sE2) produced in insect cells possesses different glycosylation patterns and is more immunogenic, as evidenced by the induction of higher titers of broadly neutralizing antibodies (bNAbs) against cell culture-derived HCV (HCVcc) harboring structural proteins from a diverse array of HCV genotypes. We affirm that continuous and discontinuous epitopes of well-characterized bNAbs are conserved, suggesting that sE2 produced in insect cells is properly folded. In a genetically humanized mouse model, active immunization with sE2 efficiently protected against challenge with a heterologous HCV genotype. These data not only demonstrate that sE2 is a promising HCV vaccine candidate, but also highlight the importance of glycosylation patterns in developing subunit viral vaccines.
  
  
  OBJECTIVE
  A prophylactic vaccine with high efficacy and low cost is urgently needed for global control of HCV infection. Induction of broadly neutralizing antibodies against most HCV genotypes has been challenging due to the antigenic diversity of the HCV genome. Here, we refined a high-yield subunit HCV vaccine that elicited broadly neutralizing antibody responses in preclinical trials. We found that soluble HCV E2 protein (sE2) produced in insect cells is distinctly glycosylated and is more immunogenic than sE2 produced in mammalian cells, suggesting that glycosylation patterns should be taken into consideration in efforts to generate antibody-based recombinant vaccines against HCV. We further showed that sE2 vaccination confers protection against HCV infection in a genetically humanized mouse model. Thus, our work identified a promising broadly protective HCV vaccine candidate that should be considered for further preclinical and clinical development.
authors.affiliation: Vaccine Research Center, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.|Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: von Schaewen
authors.affiliation: Vaccine Research Center, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.|Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Wanyin
authors.initials: W
authors.lastname: Tao
authors.affiliation: Vaccine Research Center, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Yunfang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Heller
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Hrebikova
authors.affiliation: Vaccine Research Center, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Deng
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Ploss
authors.affiliation: Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China huangzhong@ips.ac.cn jzhong@sibs.ac.cn.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Vaccine Research Center, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China huangzhong@ips.ac.cn jzhong@sibs.ac.cn.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Huang
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000096:biosynthesis*; D000918:Antibody Specificity; D002460:Cell Line; D004330:Drosophila; D005260:Female; D006031:Glycosylation; D016174:Hepacivirus / Q000235:genetics / Q000276:immunology*; D018937:Hepatitis C Antibodies / Q000096:biosynthesis*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D017384:Sequence Deletion; D012995:Solubility; D022223:Vaccines, Subunit / Q000737:chemistry / Q000276:immunology; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014761:Viral Hepatitis Vaccines / Q000737:chemistry / Q000276:immunology*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology
chemical_list: D057134:Antibodies, Neutralizing; C400562:HVR1 protein, Hepatitis C virus; D018937:Hepatitis C Antibodies; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D014759:Viral Envelope Proteins; D014761:Viral Hepatitis Vaccines; D014764:Viral Proteins; C091015:glycoprotein E2, Hepatitis C virus