Epitopes described in "Cooperativity in virus neutralization by human monoclonal antibodies to two adjacent regions located at the amino terminus of hepatitis C virus E2 glycoprotein."

Article Authors:Zhenyong Keck; Wenyan Wang; Yong Wang; Patrick Lau; Thomas H R Carlsen; Jannick Prentoe; Jinming Xia; Arvind H Patel; Jens Bukh; Steven K H Foung
Article Title:Cooperativity in virus neutralization by human monoclonal antibodies to two adjacent regions located at the amino terminus of hepatitis C virus E2 glycoprotein.
Reference Detail
Reference ID:1025364
Abstract:A challenge for hepatitis C virus (HCV) vaccine development is defining conserved epitopes that induce protective antibodies against this highly diverse virus. An envelope glycoprotein (E2) segment located at amino acids (aa) 412 to 423 contains highly conserved neutralizing epitopes. While polyclonal antibodies to aa 412 to 423 from HCV-infected individuals confirmed broad neutralization, conflicting findings have been reported on polyclonal antibodies to an adjacent region, aa 434 to 446, that may or may not interfere with neutralization by antibodies to aa 412 to 423. To define the interplay between these antibodies, we isolated human monoclonal antibodies (HMAbs) to aa 412 to 423, designated HC33-related HMAbs (HC33 HMAbs), and characterized their interactions with other HMAbs to aa 434 to 446. A subset of the HC33 HMAbs neutralized genotype 1 to 6 infectious cell culture-derived HCV virions (HCVcc) with various activities. Although nonneutralizing HC33 HMAbs were isolated, they had lower binding affinities than neutralizing HC33 HMAbs. These antibodies could be converted to neutralizing antibodies by affinity maturation. Unidirectional competition for binding to E2 was observed between HC33 HMAbs and HMAbs to aa 434 to 446. When HMAbs to aa 434 to 446, which mediated neutralization, were combined with neutralizing HC33 HMAbs, biphasic patterns in neutralization were observed. A modest degree of antagonism was observed at lower concentrations, and a modest degree of synergism was observed at higher concentrations. However, the overall effect was additive neutralization. A similar pattern was observed when these antibodies were combined to block E2 binding to the HCV coreceptor, CD81. These findings demonstrate that both of these E2 regions participate in epitopes mediating virus neutralization and that the antibodies to aa 412 to 423 and aa 434 to 446 do not hinder their respective virus-neutralizing activities.
Affiliations:Department of Pathology, Stanford University School of Medicine, Stanford, California, USA.
Reference Type:Literature
PubMed ID:23097455
Journal:J Virol
Journal Volume:87
Article Pages:37-51
Journal ISSN:1098-5514
Article Chemical List:Antibodies, Monoclonal;Antibodies, Neutralizing;Antibodies, Viral;Epitopes, B-Lymphocyte;Viral Envelope Proteins;glycoprotein E2, Hepatitis C virus
Article MeSH List:Antibodies, Monoclonal(immunology; isolation & purification); Antibodies, Neutralizing(immunology; isolation & purification); Antibodies, Viral(immunology; isolation & purification); Cell Line; Epitopes, B-Lymphocyte(immunology); Hepacivirus(immunology); Humans; Viral Envelope Proteins(immunology)
Curation Last Updated:2015-07-24 20:11:16