Role of the virion host shutoff (vhs) of herpes simplex virus type 1 in latency and pathogenesis.
The herpes simplex virus type 1 (HSV-1) UL41 gene product, virion host shutoff (vhs), has homologs among five alphaherpesviruses (HSV-1, HSV-2, pseudorabies virus, varicella-zoster virus, and equine herpesvirus 1), suggesting a role for this protein in neurotropism. A mutant virus, termed UL41NHB, which carries a nonsense linker in the UL41 open reading frame at amino acid position 238 was generated. UL41NHB and a marker-rescued virus, UL41NHB-R, were characterized in vitro and tested for their ability to replicate in vitro and in vivo and to establish and reactivate from latency in a mouse eye model. As demonstrated by Western blotting (immunoblotting) and Northern (RNA) blotting procedures, UL41NHB encodes an appropriately truncated vhs protein and, as expected for a vhs null mutant, fails to induce the degradation of cellular glyceraldehyde-3-phosphate dehydrogenase mRNA. The growth of UL41NHB was not significantly altered in one-step growth curves in Vero or mouse C3H/10T1/2 cells but was impaired in corneas, in trigeminal ganglia, and in brains of mice compared with the growth of KOS and UL41NHB-R. As a measure of establishment of latency, quantitative DNA PCR showed that the amount of viral DNA within trigeminal ganglia latently infected with UL41NHB was reduced by approximately 30-fold compared with that in KOS-infected ganglia and by 50-fold compared with that in UL41NHB-R-infected ganglia. Explant cocultivation studies revealed a low reactivation frequency for UL41NHB (1 of 28 ganglia, or 4%) compared with that for KOS (56 of 76, or 74%) or UL41NHB-R (13 of 20 or 65%). Taken together, these results demonstrate that vhs represents a determinant of viral pathogenesis.
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000473:pathology / Q000821:virology*; D002460:Cell Line; D002522:Chlorocebus aethiops; D017931:DNA Primers; D004279:DNA, Viral / Q000032:analysis; D005260:Female; D006561:Herpes Simplex / Q000473:pathology*; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016133:Polymerase Chain Reaction; D012260:Ribonucleases; D012668:Trigeminal Ganglion / Q000473:pathology / Q000821:virology*; D014709:Vero Cells; D014764:Viral Proteins / Q000096:biosynthesis / Q000502:physiology*; D014771:Virion / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D017735:Virus Latency
D017931:DNA Primers; D004279:DNA, Viral; D014764:Viral Proteins; C070722:virion host shutoff protein, Simplexvirus; D012260:Ribonucleases