Antibody evasion by the N terminus of murid herpesvirus-4 glycoprotein B

• Laurent Gillet ^[1] ; Philip G Stevenson ^[1]
  1. [1] University of Cambridge

     University of Cambridge

     Cambridge District, Reino Unido

     
• Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 26, Nº. 24, 2007, págs. 5131-5142
• Idioma: inglés
• Enlaces
  • Texto completo
• Resumen

  • Herpesviruses characteristically transmit infection from immune hosts. Although their success in escaping neutralization by pre-formed antibody is indisputable, the underlying molecular mechanisms remain largely unknown. Glycoprotein B (gB) is the most conserved component of the herpesvirus entry machinery and its N terminus (gB-NT) is a common neutralization target. We used murid herpesvirus-4 to determine how gB-NT contributes to the virus–antibody interaction. Deleting gB-NT had no obvious impact on virus replication, but paradoxically increased virion neutralization by immune sera. This reflected greater antibody access to neutralization epitopes on gH/gL, with which gB was associated. gB-NT itself was variably protected against antibody by O-linked glycans; on virions from epithelial cells it was protected almost completely. gB-NT therefore provides a protective and largely protected cover for a vulnerable part of gH/gL. The conservation of predicted glycosylation sites in other mammalian herpesvirus gB-NTs suggests that this evasion mechanism is widespread. Interestingly, the gB-NT glycans that blocked antibody binding could be targeted for neutralization instead by a lectin, suggesting a means of therapeutic counterattack.