Institute of Biostructures and Bioimaging, CNR and CIRPeB, University of Naples Federico II, Napoli, Italy., Dept. of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Napoli, Italy., Institute of Biostructures and Bioimaging, CNR and CIRPeB, University of Naples Federico II, Napoli, Italy Dept. of Pharmacy, University of Naples Federico II, Napoli, Italy., Kedrion SpA, Lucca, Italy., Institute of Biostructures and Bioimaging, CNR and CIRPeB, University of Naples Federico II, Napoli, Italy Second University of Naples., Medical Research Council - University of Glasgow Centre for Virus Research, Glasgow, UK., Medical Research Council - University of Glasgow Centre for Virus Research, Glasgow, UK. menotti.ruvo@unina.it arvind.patel@glasgow.ac.uk., Institute of Biostructures and Bioimaging, CNR and CIRPeB, University of Naples Federico II, Napoli, Italy menotti.ruvo@unina.it arvind.patel@glasgow.ac.uk.,
Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
Department of Pharmacy, University of Naples Federico II, Naples, Italy
Bioker Multimedica, Naples, Italy
Kedrion SpA, Lucca, Italy.
Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom.
References: Not available.
Generation and characterization of monoclonal antibodies against a cyclic variant of Hepatitis C Virus E2 epitope 412-422
The hepatitis C virus (HCV) E2 envelope glycoprotein is crucial for virus entry into hepatocytes. A conserved region of E2 encompassing amino acids 412 to 423 (epitope I) and containing Trp420, a residue critical for virus entry, is recognized by several broadly neutralizing antibodies. Peptides embodying this epitope I sequence adopt a β-hairpin conformation when bound to neutralizing monoclonal antibodies (MAbs) AP33 and HCV1. We therefore generated new mouse MAbs that were able to bind to a cyclic peptide containing E2 residues 412 to 422 (C-epitope I) but not to the linear counterpart. These MAbs bound to purified E2 with affinities of about 50 nM, but they were unable to neutralize virus infection. Structural analysis of the complex between C-epitope I and one of our MAbs (C2) showed that the Trp420 side chain is largely buried in the combining site and that the Asn417 side chain, which is glycosylated in E2 and solvent exposed in other complexes, is slightly buried upon C2 binding. Also, the orientation of the cyclic peptide in the antibody-combining site is rotated by 180° compared to the orientations of the other complexes. All these structural features, however, do not explain the lack of neutralization activity. This is instead ascribed to the high degree of selectivity of the new MAbs for the cyclic epitope and to their inability to interact with the epitope in more flexible and extended conformations, which recent data suggest play a role in the mechanisms of neutralization escape. IMPORTANCE: Hepatitis C virus (HCV) remains a major health care burden, affecting almost 3% of the global population. The conserved epitope comprising residues 412 to 423 of the viral E2 glycoprotein is a valid vaccine candidate because antibodies recognizing this region exhibit potent neutralizing activity. This epitope adopts a β-hairpin conformation when bound to neutralizing MAbs. We explored the potential of cyclic peptides mimicking this structure to elicit anti-HCV antibodies. MAbs that specifically recognize a cyclic variant of the epitope bind to soluble E2 with a lower affinity than other blocking antibodies and do not neutralize virus. The structure of the complex between one such MAb and the cyclic epitope, together with new structural data showing the linear peptide bound to neutralizing MAbs in extended conformations, suggests that the epitope displays a conformational flexibility that contributes to neutralization escape. Such features can be of major importance for the design of epitope-based anti-HCV vaccines.
Generation and characterization of monoclonal antibodies against a cyclic variant of Hepatitis C Virus E2 epitope 412-422
Bogdanovich S, Kim Y, Mizutani T, Yasuma R, Tudisco L, Cicatiello V, Bastos-carvalho A, Kerur N, Hirano Y, Baffi JZ, Tarallo V, Li S, Yasuma T, Arpitha P, Fowler BJ, Wright CB, Apicella I, Greco A, Brunetti A, Ruvo M, Sandomenico A, Nozaki M, Ijima R, Kaneko H, Ogura Y, Terasaki H, Ambati BK, Leusen JH, Langdon WY, Clark MR, Armour KL, Bruhns P, Verbeek JS, Gelfand BD, De Falco S, Ambati J * Human IgG1 antibodies suppress angiogenesis in a target-independent manner(682 views) Signal Transduct Target Ther (ISSN: 2059-3635print), 2016; 1: N/D-N/D. Impact Factor:0 ViewExport to BibTeXExport to EndNote
Kim YH, Shin SW, Pellicano R, Fagoonee S, Choi IJ, Kim YI, Park B, Choi JM, Kim SG, Choi J, Park JY, Oh S, Yang HJ, Lim JH, Im JP, Kim JS, Jung HC, Ponzetto A, Figura N, Malfertheiner P, Choi IJ, Kook MC, Kim YI, Cho SJ, Lee JY, Kim CG, Park B, Nam BH, Bae SE, Choi KD, Choe J, Kim SO, Na HK, Choi JY, Ahn JY, Jung KW, Lee J, Kim DH, Chang HS, Song HJ, Lee GH, Jung HY, Seta T, Takahashi Y, Noguchi Y, Shikata S, Sakai T, Sakai K, Yamashita Y, Nakayama T, Leja M, Park JY, Murillo R, Liepniece-karele I, Isajevs S, Kikuste I, Rudzite D, Krike P, Parshutin S, Polaka I, Kirsners A, Santare D, Folkmanis V, Daugule I, Plummer M, Herrero R, Tsukamoto T, Nakagawa M, Kiriyama Y, Toyoda T, Cao X, Corral JE, Mera R, Dye CW, Morgan DR, Lee YC, Lin JT, Garcia Martin R, Matia Cubillo A, Lee SH, Park JM, Han YM, Ko WJ, Hahm KB, Leontiadis GI, Ford AC, Ichinose M, Sugano K, Jeong M, Park JM, Han YM, Park KY, Lee DH, Yoo JH, Cho JY, Hahm KB, Bang CS, Baik GH, Shin IS, Kim JB, Suk KT, Yoon JH, Kim YS, Kim DJ * Helicobacter pylori Eradication for Prevention of Metachronous Recurrence after Endoscopic Resection of Early Gastric Cancer(682 views) N Engl J Med (ISSN: 0028-4793, 0028-4793linking, 1533-4406electronic), 2015 Jun; 30642104201566393291: 749-756. Impact Factor:59.558 ViewExport to BibTeXExport to EndNote