PMID- 29321311 OWN - NLM STAT- MEDLINE DCOM- 20180417 LR - 20191210 IS - 1098-5514 (Electronic) IS - 0022-538X (Print) IS - 0022-538X (Linking) VI - 92 IP - 7 DP - 2018 Apr 1 TI - Herpes Simplex Virus 1 Mutant with Point Mutations in UL39 Is Impaired for Acute Viral Replication in Mice, Establishment of Latency, and Explant-Induced Reactivation. LID - 10.1128/JVI.01654-17 [doi] LID - e01654-17 AB - In the process of generating herpes simplex virus 1 (HSV-1) mutations in the viral regulatory gene encoding infected cell protein 0 (ICP0), we isolated a viral mutant, termed KOS-NA, that was severely impaired for acute replication in the eyes and trigeminal ganglia (TG) of mice, defective in establishing a latent infection, and reactivated poorly from explanted TG. To identify the secondary mutation(s) responsible for the impaired phenotypes of this mutant, we sequenced the KOS-NA genome and noted that it contained two nonsynonymous mutations in UL39, which encodes the large subunit of ribonucleotide reductase, ICP6. These mutations resulted in lysine-to-proline (residue 393) and arginine-to-histidine (residue 950) substitutions in ICP6. To determine whether alteration of these amino acids was responsible for the KOS-NA phenotypes in vivo, we recombined the wild-type UL39 gene into the KOS-NA genome and rescued its acute replication phenotypes in mice. To further establish the role of UL39 in KOS-NA's decreased pathogenicity, the UL39 mutations were recombined into HSV-1 (generating UL39(mut)), and this mutant virus showed reduced ocular and TG replication in mice comparable to that of KOS-NA. Interestingly, ICP6 protein levels were reduced in KOS-NA-infected cells relative to the wild-type protein. Moreover, we observed that KOS-NA does not counteract caspase 8-induced apoptosis, unlike wild-type strain KOS. Based on alignment studies with other HSV-1 ICP6 homologs, our data suggest that amino acid 950 of ICP6 likely plays an important role in ICP6 accumulation and inhibition of apoptosis, consequently impairing HSV-1 pathogenesis in a mouse model of HSV-1 infection.IMPORTANCE HSV-1 is a major human pathogen that infects approximately 80% of the human population and can be life threatening to infected neonates or immunocompromised individuals. Effective therapies for treatment of recurrent HSV-1 infections are limited, which emphasizes a critical need to understand in greater detail the events that modulate HSV-1 replication and pathogenesis. In the current study, we identified a neuroattenuated HSV-1 mutant (i.e., KOS-NA) that contains novel mutations in the UL39 gene, which codes for the large subunit of ribonucleotide reductase (also known as ICP6). This mutant form of ICP6 was responsible for the attenuation of KOS-NA in vivo and resulted in diminished ICP6 protein levels and antiapoptotic effect. Thus, we have determined that subtle alteration of the UL39 gene regulates expression and functions of ICP6 and severely impacts HSV-1 pathogenesis, potentially making KOS-NA a promising vaccine candidate against HSV-1. CI - Copyright (c) 2018 American Society for Microbiology. FAU - Mostafa, Heba H AU - Mostafa HH AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Thompson, Thornton W AU - Thompson TW AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Konen, Adam J AU - Konen AJ AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Haenchen, Steve D AU - Haenchen SD AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Hilliard, Joshua G AU - Hilliard JG AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Macdonald, Stuart J AU - Macdonald SJ AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. FAU - Morrison, Lynda A AU - Morrison LA AD - Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri, USA. FAU - Davido, David J AU - Davido DJ AD - Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA ddavido@ku.edu. LA - eng GR - R01 OD010974/OD/NIH HHS/United States GR - UL1 RR024992/RR/NCRR NIH HHS/United States GR - P30 CA091842/CA/NCI NIH HHS/United States GR - UL1 TR000448/TR/NCATS NIH HHS/United States GR - UL1 TR002345/TR/NCATS NIH HHS/United States GR - R21 EY019739/EY/NEI NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20180314 PL - United States TA - J Virol JT - Journal of virology JID - 0113724 RN - 0 (Capsid Proteins) RN - 0 (Herpes Simplex Virus Vaccines) RN - 0 (Viral Proteins) RN - 0 (herpes simplex virus type 1-protein ICP6) SB - IM MH - Animals MH - *Capsid Proteins/genetics/metabolism MH - Chlorocebus aethiops MH - Disease Models, Animal MH - Female MH - *Herpes Simplex/genetics/metabolism/pathology MH - Herpes Simplex Virus Vaccines/genetics/metabolism MH - Herpesvirus 1, Human/*physiology MH - Mice MH - *Point Mutation MH - Vero Cells MH - Viral Proteins/biosynthesis/genetics MH - Virus Activation/*genetics MH - Virus Latency/*genetics PMC - PMC5972887 OTO - NOTNLM OT - HSV-1 OT - ICP6 OT - UL39 OT - antiapoptosis OT - pathogenesis OT - ribonucleotide reductase OT - viral mutant EDAT- 2018/01/13 06:00 MHDA- 2018/04/18 06:00 PMCR- 2018/09/14 CRDT- 2018/01/12 06:00 PHST- 2017/10/18 00:00 [received] PHST- 2018/01/03 00:00 [accepted] PHST- 2018/01/13 06:00 [pubmed] PHST- 2018/04/18 06:00 [medline] PHST- 2018/01/12 06:00 [entrez] PHST- 2018/09/14 00:00 [pmc-release] AID - JVI.01654-17 [pii] AID - 01654-17 [pii] AID - 10.1128/JVI.01654-17 [doi] PST - epublish SO - J Virol. 2018 Mar 14;92(7):e01654-17. doi: 10.1128/JVI.01654-17. Print 2018 Apr 1.