title: A single-amino-acid substitution in herpes simplex virus 1 envelope glycoprotein B at a site required for binding to the paired immunoglobulin-like type 2 receptor alpha (PILRalpha) abrogates PILRalpha-dependent viral entry and reduces pathogenesis.
abstract: Paired immunoglobulin-like type 2 receptor α (PILRα) is a herpes simplex virus 1 (HSV-1) entry receptor that associates with O-glycans on HSV-1 envelope glycoprotein B (gB). Two threonine residues (Thr-53 and Thr-480) in gB, which are required for the addition of the principal gB O-glycans, are essential for binding to soluble PILRα. However, the role of the two threonines in PILRα-dependent viral entry remains to be elucidated. Therefore, we constructed a recombinant HSV-1 carrying an alanine replacement of gB Thr-53 alone (gB-T53A) or of both gB Thr-53 and Thr-480 (gB-T53/480A) and demonstrated that these mutations abrogated viral entry in CHO cells expressing PILRα. In contrast, the mutations had no effect on viral entry in CHO cells expressing known host cell receptors for HSV-1 gD, viral entry in HL60 cells expressing myelin-associated glycoprotein (MAG) (another HSV-1 gB receptor), viral attachment to heparan sulfate, and viral replication in PILRα-negative cells. These results support the hypothesis that gB Thr-53 and Thr-480 as well as gB O-glycosylation, probably at these sites, are critical for PILRα-dependent viral entry. Interestingly, following corneal inoculation in mice, the gB-T53A and gB-T53/480A mutations significantly reduced viral replication in the cornea, the development of herpes stroma keratitis, and neuroinvasiveness. The abilities of HSV-1 to enter cells in a PILRα-dependent manner and to acquire specific carbohydrates on gB are therefore linked to an increase in viral replication and virulence in the experimental murine model.
authors.affiliation: Division of Viral Infection, Department of Infectious Disease Control, International Research Center for Infectious Diseases, the Institute of Medical Science, the University of Tokyo, Minato-ku, Tokyo 108-8639, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Arii
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Tomomi
authors.initials: T
authors.lastname: Morimoto
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Suenaga
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Akashi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Arase
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D005260:Female; D006031:Glycosylation; D018259:Herpesvirus 1, Human / Q000235:genetics* / Q000472:pathogenicity* / Q000502:physiology; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000502:physiology; D006801:Humans; D008561:Membrane Fusion / Q000235:genetics / Q000502:physiology; D051379:Mice; D008813:Mice, Inbred ICR; D050505:Mutant Proteins / Q000235:genetics / Q000502:physiology; D011971:Receptors, Immunologic / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000502:physiology; D014774:Virulence / Q000235:genetics / Q000502:physiology; D053586:Virus Internalization; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D017931:DNA Primers; D050505:Mutant Proteins; C548037:PILRalpha protein, mouse; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C040495:glycoprotein B, Simplexvirus