title: Antibody evasion by a gammaherpesvirus O-glycan shield.
abstract: All gammaherpesviruses encode a major glycoprotein homologous to the Epstein-Barr virus gp350. These glycoproteins are often involved in cell binding, and some provide neutralization targets. However, the capacity of gammaherpesviruses for long-term transmission from immune hosts implies that in vivo neutralization is incomplete. In this study, we used Bovine Herpesvirus 4 (BoHV-4) to determine how its gp350 homolog--gp180--contributes to virus replication and neutralization. A lack of gp180 had no impact on the establishment and maintenance of BoHV-4 latency, but markedly sensitized virions to neutralization by immune sera. Antibody had greater access to gB, gH and gL on gp180-deficient virions, including neutralization epitopes. Gp180 appears to be highly O-glycosylated, and removing O-linked glycans from virions also sensitized them to neutralization. It therefore appeared that gp180 provides part of a glycan shield for otherwise vulnerable viral epitopes. Interestingly, this O-glycan shield could be exploited for neutralization by lectins and carbohydrate-specific antibody. The conservation of O-glycosylation sites in all gp350 homologs suggests that this is a general evasion mechanism that may also provide a therapeutic target.
authors: Immunology-Vaccinology B43b, Department of Infectious and Parasitic Diseases B43b, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium.
authors: Bénédicte
authors: B
authors: Machiels
authors: Céline
authors: C
authors: Lété
authors: Antoine
authors: A
authors: Guillaume
authors: Jan
authors: J
authors: Mast
authors: Philip G
authors: PG
authors: Stevenson
authors: Alain
authors: A
authors: Vanderplasschen
authors: Laurent
authors: L
authors: Gillet
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000939:Epitopes / Q000276:immunology; D006031:Glycosylation; D026021:Herpesvirus 4, Bovine / Q000235:genetics / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D011817:Rabbits; D016415:Sequence Alignment; D014759:Viral Envelope Proteins / Q000235:genetics / Q000502:physiology*; D014771:Virion / Q000276:immunology; D014779:Virus Replication / Q000276:immunology
chemical_list: D000939:Epitopes; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins