{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T09:49:37Z","timestamp":1774000177383,"version":"3.50.1"},"reference-count":55,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T00:00:00Z","timestamp":1773964800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      Hepatitis C virus (HCV) infection poses a major global risk for chronic liver disease, underscoring the critical need for prevention. Our previous studies demonstrated that HCV-modified soluble E1\/E2\n                      <jats:sub>F442NYT<\/jats:sub>\n                      envelope glycoproteins delivered from an mRNA-lipid nanoparticle (LNP) vaccine platform induce immune responses\n                      <jats:italic>in vitro<\/jats:italic>\n                      in human cells and\n                      <jats:italic>in vivo<\/jats:italic>\n                      in immunized mice. These findings prompted us to analyze the sE1-derived induction of broadly cross-genotype HCV protective antibody response.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Analyses for the evaluation of linear B-cell epitopes, specifically antibody elicitation by genotype 1a E1 mRNA-LNP immunization, were performed using a panel of E1 overlapping peptides. HCV pseudotype neutralization, interruption by antibody binding to epitope regions, and association between E1\/E2 were biochemically analyzed for the impairment of known E2 receptor-binding functions, including surrogate virus neutralization.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Binding inhibition-based ELISA identified peptides having a distinct reactivity pattern of immune mouse sera, revealing four linear regions (Groups A\u2013D). One of the peptides (Group A, P1) corresponded to an antigenic region previously characterized as a key linear B-cell epitope. HCV pseudotype neutralization assay using rabbit anti-P1 peptide serum demonstrated multi-HCV genotype neutralization. The relatively conserved linear B-cell epitope was found to localize in the \u03b11 helix region, closer to the N-terminal ectodomain of E1\/E2 major receptor-binding area. However, a much-conserved P2 epitope (Group D), with residues reported to interplay with the tight junction protein claudin-1 and scavenger receptor B type I, induced a detectable HCV pseudotype neutralization. Interruption by antibody binding to the P1 and P2 regions may impair intimate association between E1\/E2, leading to the impairment of known E2 receptor-binding functions, including virus neutralization activity. Surface plasmon resonance suggested similar antibody binding affinity of the two rabbit antibodies (~10\n                      <jats:sup>\u22128<\/jats:sup>\n                      M) to the unmodified E1\/E2. The Group B peptide awaits further characterization for HCV functional inhibitory roles, while the Group C peptide is characterized as a putative fusion peptide and involved in cross-talk with E2.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Collectively, the findings identified novel B-cell epitopes of E1 glycoprotein cross-reactive among HCV genotypes and may serve as a promising candidate to include for a rational design of a pan-genotypic HCV vaccine.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fimmu.2026.1745299","type":"journal-article","created":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T06:39:00Z","timestamp":1773988740000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Hepatitis C virus E1 protein-specific linear B-cell epitopes, pan-genotype reactivity, and functional relevance"],"prefix":"10.3389","volume":"17","author":[{"given":"Babu E","family":"Preedia","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, Saint Louis University","place":["Saint Louis, MO, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuki","family":"Haga","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Saint Louis University","place":["Saint Louis, MO, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ranjit","family":"Ray","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, Saint Louis University","place":["Saint Louis, MO, United States"]},{"name":"Department of Molecular Microbiology and Immunology, Saint Louis University","place":["Saint Louis, MO, United States"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,20]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"ofx264","DOI":"10.1093\/ofid\/ofx264","article-title":"Direct-acting antivirals improve access to care and cure for patients with HIV and chronic HCV infection","volume":"5","author":"Collins","year":"2018","journal-title":"Open Forum Infect Dis"},{"key":"B2","doi-asserted-by":"crossref","first-page":"1917","DOI":"10.3389\/fimmu.2018.01917","article-title":"Hepatitis C virus envelope glycoproteins: A balancing act of order and disorder","volume":"9","author":"Yost","year":"2018","journal-title":"Front Immunol"},{"key":"B3","doi-asserted-by":"crossref","first-page":"717","DOI":"10.1016\/j.chom.2018.10.012","article-title":"Broadly neutralizing antibody mediated clearance of human hepatitis C virus infection","volume":"24","author":"Kinchen","year":"2018","journal-title":"Cell Host Microbe"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1128\/jvi.00523-22","article-title":"Modified E2 glycoprotein of hepatitis C virus enhances proinflammatory cytokines and protective immune response","volume":"96","author":"Vijayamahantesh","year":"2022","journal-title":"J Virol"},{"key":"B5","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1038\/s41541-023-00635-9","article-title":"Hepatitis C virus E1 and modified E2 delivered from an mRNA vaccine induces protective immunity","volume":"8","author":"Patra","year":"2023","journal-title":"NPJ Vaccines"},{"key":"B6","doi-asserted-by":"crossref","DOI":"10.1128\/jvi.01809-23","article-title":"Hepatitis C virus modified sE2(F442NYT) as an antigen in candidate vaccine facilitates human immune cell activation","volume":"98","author":"Haga","year":"2024","journal-title":"J Virol"},{"key":"B7","doi-asserted-by":"crossref","DOI":"10.1073\/pnas.0504877103","article-title":"Construction and characterization of infectious intragenotypic and intergenotypic hepatitis C virus chimeras","volume":"103","author":"Pietschmann","year":"2006","journal-title":"Proc Natl Acad Sci U S A"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.00048-17","article-title":"Identification of novel functions for hepatitis C virus envelope glycoprotein E1 in virus entry and assembly","volume":"91","author":"Haddad","year":"2017","journal-title":"J Virol"},{"key":"B9","doi-asserted-by":"crossref","first-page":"110859","DOI":"10.1016\/j.celrep.2022.110859","article-title":"Sites of vulnerability in HCV E1E2 identified by comprehensive functional screening","volume":"39","author":"Pfaff-Kilgore","year":"2022","journal-title":"Cell Rep"},{"key":"B10","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1038\/s41598-017-00320-7","article-title":"A biologically-validated HCV E1E2 heterodimer structural model","volume":"7","author":"Castelli","year":"2017","journal-title":"Sci Rep"},{"key":"B11","doi-asserted-by":"crossref","DOI":"10.3748\/wjg.v12.i16.2530","article-title":"Antibody to E1 peptide of hepatitis C virus genotype 4 inhibits virus binding and entry to HepG2 cells in vitro","volume":"12","author":"El-Awady","year":"2006","journal-title":"World J Gastroenterol"},{"key":"B12","first-page":"203","article-title":"Improvement of chronic active hepatitis C in chronically infected chimpanzees after therapeutic vaccination with the HCV E1 protein","volume":"63","author":"Maertens","year":"2000","journal-title":"Acta Gastroenterol Belg"},{"key":"B13","doi-asserted-by":"crossref","DOI":"10.1002\/(SICI)1096-9071(200002)60:2<126::AID-JMV4>3.0.CO;2-L","article-title":"Long term response to interferon treatment in chronic hepatitis C patients is associated with a significant reduction in anti-E1 envelope antibody titers","volume":"60","author":"Depraetere","year":"2000","journal-title":"J Med Virol"},{"key":"B14","doi-asserted-by":"crossref","DOI":"10.1002\/(SICI)1096-9071(199708)52:4<441::AID-JMV17>3.0.CO;2-J","article-title":"Serological and molecular analysis of hepatitis C virus envelope regions 1 and 2 during acute and chronic infections in chimpanzees","volume":"52","author":"van Doorn","year":"1997","journal-title":"J Med Virol"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1053\/jhep.2000.9876","article-title":"Antibodies against hepatitis C virus-like particles and viral clearance in acute and chronic hepatitis C","volume":"32","author":"Baumert","year":"2000","journal-title":"Hepatology"},{"key":"B16","doi-asserted-by":"crossref","DOI":"10.1128\/jvi.68.7.4420-4426.1994","article-title":"Peptide immunogen mimicry of putative E1 glycoprotein-specific epitopes in hepatitis C virus","volume":"68","author":"Ray","year":"1994","journal-title":"J Virol"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1002\/hep.24523","article-title":"Hepatitis C virus E1 envelope glycoprotein interacts with apolipoproteins in facilitating entry into hepatocytes","volume":"54","author":"Mazumdar","year":"2011","journal-title":"Hepatology"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/j.virol.2004.11.034","article-title":"Folding and dimerization of hepatitis C virus E1 and E2 glycoproteins in stably transfected CHO cells","volume":"332","author":"Brazzoli","year":"2005","journal-title":"Virology"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1006\/viro.1997.8516","article-title":"Delineation of regions important for heteromeric association of hepatitis C virus E1 and E2","volume":"231","author":"Yi","year":"1997","journal-title":"Virology"},{"key":"B20","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.76.18.9562.2002","article-title":"Analysis of antigenicity and topology of E2 glycoprotein present on recombinant hepatitis C virus-like particles","volume":"76","author":"Clayton","year":"2002","journal-title":"J Virol"},{"key":"B21","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.2015149118","article-title":"Design of a native-like secreted form of the hepatitis C virus E1E2 heterodimer","volume":"118","author":"Guest","year":"2021","journal-title":"Proc Natl Acad Sci U.S.A"},{"key":"B22","doi-asserted-by":"crossref","DOI":"10.1073\/pnas.1114927109","article-title":"Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus","volume":"109","author":"Giang","year":"2012","journal-title":"Proc Natl Acad Sci U S A"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.02070-18","article-title":"Broadly neutralizing antibodies targeting new sites of vulnerability in hepatitis C virus E1E2","volume":"93","author":"Colbert","year":"2019","journal-title":"J Virol"},{"key":"B24","doi-asserted-by":"crossref","DOI":"10.1172\/JCI130720","article-title":"Plasma deconvolution identifies broadly neutralizing antibodies associated with hepatitis C virus clearance","volume":"129","author":"Kinchen","year":"2019","journal-title":"J Clin Invest"},{"key":"B25","doi-asserted-by":"crossref","first-page":"1058","DOI":"10.1053\/j.gastro.2019.11.282","article-title":"Antibody responses to immunization with HCV envelope glycoproteins as a baseline for B-cell-based vaccine development","volume":"158","author":"Chen","year":"2020","journal-title":"Gastroenterology"},{"key":"B26","doi-asserted-by":"crossref","DOI":"10.1080\/14760584.2016.1194759","article-title":"Hepatitis C virus vaccine candidates inducing protective neutralizing antibodies","volume":"15","author":"Fauvelle","year":"2016","journal-title":"Expert Rev Vaccines"},{"key":"B27","article-title":"Architecture of the hepatitis C virus E1 glycoprotein transmembrane domain studied by NMR","volume":"1838","author":"Zazrin","year":"2014","journal-title":"Biochim Biophys Acta"},{"key":"B28","doi-asserted-by":"publisher","DOI":"10.1128\/jvi.01355-25","article-title":"Hepatitis C virus modified SE2F442NYT-mRNA-LNP candidate vaccine promotes helper CXCR5+T cells","volume":"99","author":"Haga","year":"2025","journal-title":"J Virol"},{"key":"B29","doi-asserted-by":"crossref","first-page":"2877","DOI":"10.1016\/j.immuni.2021.11.001","article-title":"Lipid nanoparticles enhance the efficacy of mRNA and protein subunit vaccines by inducing robust T follicular helper cell and humoral responses","volume":"54","author":"Alameh","year":"2021","journal-title":"Immunity"},{"key":"B30","doi-asserted-by":"crossref","DOI":"10.1093\/nar\/gkx346","article-title":"BepiPred-2.0: improving sequence-based B-cell epitope prediction using conformational epitopes","volume":"45","author":"Jespersen","year":"2017","journal-title":"Nucleic Acids Res"},{"key":"B31","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4939-8976-8_30","article-title":"Standardized method for the study of antibody neutralization of HCV pseudoparticles (HCVpp)","volume":"1911","author":"Bailey","year":"2019","journal-title":"Methods Mol Biol"},{"key":"B32","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.01872-07","article-title":"Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus","volume":"82","author":"Meunier","year":"2008","journal-title":"J Virol"},{"key":"B33","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1186\/1423-0127-16-89","article-title":"Mutagenesis of the fusion peptide-like domain of hepatitis C virus E1 glycoprotein: involvement in cell fusion and virus entry","volume":"16","author":"Li","year":"2009","journal-title":"J BioMed Sci"},{"key":"B34","doi-asserted-by":"publisher","DOI":"10.1002\/hep.26733","article-title":"Critical interaction between E1 and E2 glycoproteins determines binding and fusion properties of hepatitis C virus during cell entry","volume":"59","author":"Douam","year":"2014","journal-title":"Hepatology"},{"key":"B35","doi-asserted-by":"crossref","DOI":"10.1371\/journal.ppat.1006908","article-title":"A protein coevolution method uncovers critical features of the Hepatitis C Virus fusion mechanism","volume":"14","author":"Douam","year":"2018","journal-title":"PloS Pathog"},{"key":"B36","doi-asserted-by":"crossref","DOI":"10.1073\/pnas.89.8.3190","article-title":"Interaction of immune sera with synthetic peptides corresponding to the structural protein region of hepatitis C virus","volume":"89","author":"Ching","year":"1992","journal-title":"Proc Natl Acad Sci U S A"},{"key":"B37","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.virol.2017.10.019","article-title":"Development and characterization of a human monoclonal antibody targeting the N-terminal region of hepatitis C virus envelope glycoprotein E1","volume":"514","author":"Mesalam","year":"2018","journal-title":"Virology"},{"key":"B38","doi-asserted-by":"crossref","first-page":"13739","DOI":"10.1038\/s41598-022-18021-1","article-title":"Prediction of B cell epitopes in proteins using a novel sequence similarity-based method","volume":"12","author":"Ras-Carmona","year":"2022","journal-title":"Sci Rep"},{"key":"B39","doi-asserted-by":"crossref","DOI":"10.1016\/j.molimm.2007.10.016","article-title":"Computational characterization of B-cell epitopes","volume":"45","author":"Rubinstein","year":"2008","journal-title":"Mol Immunol"},{"key":"B40","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.molimm.2012.06.001","article-title":"Structural analysis of B-cell epitopes in antibody:protein complexes","volume":"53","author":"Kringelum","year":"2013","journal-title":"Mol Immunol"},{"key":"B41","doi-asserted-by":"crossref","first-page":"1315","DOI":"10.3389\/fimmu.2018.01315","article-title":"The neutralizing face of hepatitis C virus E2 envelope glycoprotein","volume":"9","author":"Tzarum","year":"2018","journal-title":"Front Immunol"},{"key":"B42","doi-asserted-by":"crossref","DOI":"10.2217\/fvl-2018-0180","article-title":"Function of the HCV E1 envelope glycoprotein in viral entry and assembly","volume":"14","author":"Moustafa","year":"2019","journal-title":"Future Virology"},{"key":"B43","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.02659-12","article-title":"Disulfide bonds in hepatitis C virus glycoprotein E1 control the assembly and entry functions of E2 glycoprotein","volume":"87","author":"Wahid","year":"2013","journal-title":"J Virol"},{"key":"B44","doi-asserted-by":"publisher","DOI":"10.1126\/science.abn9884","article-title":"Structure of the hepatitis C virus E1E2 glycoprotein complex","volume":"378","author":"Torrents de la Pe\u00f1a","year":"2022","journal-title":"Science"},{"key":"B45","doi-asserted-by":"crossref","first-page":"126106","DOI":"10.1016\/j.vaccine.2024.07.007","article-title":"Reverse vaccinology approach for identification of epitopes from E1 protein as peptide vaccine against HCV: A proof of concept","volume":"42","author":"Meshram","year":"2024","journal-title":"Vaccine"},{"key":"B46","doi-asserted-by":"crossref","first-page":"1411","DOI":"10.3389\/fimmu.2018.01411","article-title":"Role of hepatitis C virus envelope glycoprotein E1 in virus entry and assembly","volume":"9","author":"Tong","year":"2018","journal-title":"Front Immunol"},{"key":"B47","doi-asserted-by":"crossref","first-page":"21808","DOI":"10.1038\/srep21808","article-title":"CD36 is a co-receptor for hepatitis C virus E1 protein attachment","volume":"6","author":"Cheng","year":"2016","journal-title":"Sci Rep"},{"key":"B48","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.02642-06","article-title":"Characterization of fusion determinants points to the involvement of three discrete regions of both E1 and E2 glycoproteins in the membrane fusion process of hepatitis C virus","volume":"81","author":"Lavillette","year":"2007","journal-title":"J Virol"},{"key":"B49","doi-asserted-by":"crossref","DOI":"10.1111\/j.1365-2893.2009.01111.x","article-title":"Mutational analysis of the hepatitis C virus E1 glycoprotein in retroviral pseudoparticles and cell-culture-derived H77\/JFH1 chimeric infectious virus particles","volume":"16","author":"Russell","year":"2009","journal-title":"J Viral Hepat"},{"key":"B50","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/1743-422X-6-12","article-title":"Analysis of a conserved RGE\/RGD motif in HCV E2 in mediating entry","volume":"6","author":"Rothwangl","year":"2009","journal-title":"Virol J"},{"key":"B51","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.00271-06","article-title":"Identification of conserved residues in the E2 envelope glycoprotein of the hepatitis C virus that are critical for CD81 binding","volume":"80","author":"Owsianka","year":"2006","journal-title":"J Virol"},{"key":"B52","doi-asserted-by":"crossref","DOI":"10.1074\/jbc.M602706200","article-title":"High density lipoprotein inhibits hepatitis C virus-neutralizing antibodies by stimulating cell entry via activation of the scavenger receptor BI","volume":"281","author":"Dreux","year":"2006","journal-title":"J Biol Chem"},{"key":"B53","doi-asserted-by":"crossref","DOI":"10.1128\/JVI.78.13.7257-7263.2004","article-title":"Human monoclonal antibody to hepatitis C virus E1 glycoprotein that blocks virus attachment and viral infectivity","volume":"78","author":"Keck","year":"2004","journal-title":"J Virol"},{"key":"B54","doi-asserted-by":"publisher","DOI":"10.1006\/viro.2000.0547","article-title":"Functional features of hepatitis C virus glycoproteins for pseudotype virus entry into mammalian cells","volume":"276","author":"Meyer","year":"2000","journal-title":"Virology"},{"key":"B55","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.02468-16","article-title":"Functional Analysis of Hepatitis C Virus (HCV) Envelope Protein E1 Using a trans-Complementation System Reveals a Dual Role of a Putative Fusion Peptide of E1 in both HCV Entry and Morphogenesis","volume":"91","author":"Tong","year":"2017","journal-title":"J Virol"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2026.1745299\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T06:39:04Z","timestamp":1773988744000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2026.1745299\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,20]]},"references-count":55,"alternative-id":["10.3389\/fimmu.2026.1745299"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2026.1745299","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,20]]},"article-number":"1745299"}}