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Zhang Y, Zeng LS, Wang J, Cai WQ, Cui W, Song TJ, Peng XC, Ma Z, Xiang Y, Cui SZ, Xin HW. Multifunctional Non-Coding RNAs Mediate Latent Infection and Recurrence of Herpes Simplex Viruses. Infect Drug Resist 2021; 14:5335-5349. [PMID: 34934329 PMCID: PMC8684386 DOI: 10.2147/idr.s334769] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/30/2021] [Indexed: 12/14/2022] Open
Abstract
Herpes simplex viruses (HSVs) often cause latent infection for a lifetime, leading to repeated recurrence. HSVs have been engineered as oncolytic HSVs. The mechanism of the latent infection and recurrence remains largely unknown, which brings great challenges and limitations to eliminate HSVs in clinic and engineer safe oHSVs. Here, we systematically reviewed the latest development of the multi-step complex process of HSV latency and reactivation. Significantly, we first summarized the three HSV latent infection pathways, analyzed the structure and expression of the LAT1 and LAT2 of HSV-1 and HSV-2, proposed the regulation of LAT expression by four pathways, and dissected the function of LAT mediated by five LAT products of miRNAs, sRNAs, lncRNAs, sncRNAs and ORFs. We further analyzed that application of HSV LAT deletion mutants in HSV vaccines and oHSVs. Our review showed that deleting LAT significantly reduced the latency and reactivation of HSV, providing new ideas for the future development of safe and effective HSV therapeutics, vaccines and oHSVs. In addition, we proposed that RNA silencing or RNA interference may play an important role in HSV latency and reactivation, which is worth validating in future.
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Affiliation(s)
- Ying Zhang
- Department of Gastroenterology, Chun’an County First People’s Hospital (Zhejiang Provincial People’s Hospital Chun’an Branch), Hangzhou, Zhejiang Province, 311700, People’s Republic of China
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Molecular Biology and Biochemistry, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
| | - Li-Si Zeng
- State Key Laboratory of Respiratory Disease, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, 510095, People’s Republic of China
| | - Juan Wang
- Department of Obstetrics and Gynecology, Lianjiang People’s Hospital, Guangdong, 524400, People’s Republic of China
| | - Wen-Qi Cai
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Molecular Biology and Biochemistry, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
| | - Weiwen Cui
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Tong-Jun Song
- Department of Neurosurgery, Shenzhen Hospital of Integrated Traditional Chinese and Western Medicine, Shenzhen, Guangdong Province, 518104, People’s Republic of China
| | - Xiao-Chun Peng
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Pathophysiology, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
| | - Zhaowu Ma
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Molecular Biology and Biochemistry, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
| | - Ying Xiang
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Molecular Biology and Biochemistry, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
| | - Shu-Zhong Cui
- State Key Laboratory of Respiratory Disease, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, 510095, People’s Republic of China
| | - Hong-Wu Xin
- Laboratory of Oncology, Center for Molecular Medicine, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
- Department of Molecular Biology and Biochemistry, School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou, Hubei, 434023, People’s Republic of China
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Yum S, Li M, Fang Y, Chen ZJ. TBK1 recruitment to STING activates both IRF3 and NF-κB that mediate immune defense against tumors and viral infections. Proc Natl Acad Sci U S A 2021; 118:e2100225118. [PMID: 33785602 PMCID: PMC8040795 DOI: 10.1073/pnas.2100225118] [Citation(s) in RCA: 221] [Impact Index Per Article: 73.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The induction of type I interferons through the transcription factor interferon regulatory factor 3 (IRF3) is considered a major outcome of stimulator of interferon genes (STING) activation that drives immune responses against DNA viruses and tumors. However, STING activation can also trigger other downstream pathways such as nuclear factor κB (NF-κB) signaling and autophagy, and the roles of interferon (IFN)-independent functions of STING in infectious diseases or cancer are not well understood. Here, we generated a STING mouse strain with a mutation (S365A) that disrupts IRF3 binding and therefore type I interferon induction but not NF-κB activation or autophagy induction. We also generated STING mice with mutations that disrupt the recruitment of TANK-binding kinase 1 (TBK1), which is important for both IRF3 and NF-κB activation but not autophagy induction (L373A or ∆CTT, which lacks the C-terminal tail). The STING-S365A mutant mice, but not L373A or ∆CTT mice, were still resistant to herpes simplex virus 1 (HSV-1) infections and mounted an antitumor response after cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) treatment despite the absence of STING-induced interferons. These results demonstrate that STING can function independently of type I interferons and autophagy, and that TBK1 recruitment to STING is essential for antiviral and antitumor immunity.
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Affiliation(s)
- Seoyun Yum
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Minghao Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Yan Fang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
| | - Zhijian J Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148;
- Center for Inflammation Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
- HHMI, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148
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Lyu C, Li WD, Peng JM, Cai XH. Identification of interaction domains in the pseudorabies virus ribonucleotide reductase large and small subunits. Vet Microbiol 2020; 246:108740. [PMID: 32605757 DOI: 10.1016/j.vetmic.2020.108740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 05/16/2020] [Accepted: 05/25/2020] [Indexed: 11/17/2022]
Abstract
Alphaherpesviral ribonucleotide reductase (RNR) is composed of large (pUL39, RR1) and small (pUL40, RR2) subunits. This enzyme can catalyze conversion of ribonucleotide to deoxynucleotide diphosphates that are further phosphorylated into deoxynucleotide triphosphate (dNTPs). The dNTPs are substrates for de novo viral DNA synthesis in infected host cells. The enzymatic activity of RNR depends on association between RR1 and RR2. However, the molecular basis underlying alphaherpesviral RNR complex formation is still largely unknown. In the current study, we investigated the pseudorabies virus (PRV) RNR interaction domains in pUL39 and pUL40. The interaction of pUL39 and pUL40 was identified by co-immunoprecipitation (co-IP) and colocalization analyses. Furthermore, the interaction amino acid (aa) domains in pUL39 and pUL40 were mapped using a series of truncated proteins. Consequently, the 90-210 aa in pUL39 was identified to be responsible for the interaction with pUL40. In turn, the 66-152, 218-258 and 280-303 aa in pUL40 could interact with pUL39, respectively. Deletion of 90-210 aa in pUL39 completely abrogated the interaction with pUL40. Deletion of 66-152, 218-258 and 280-303 aa in pUL40 remarkably weakened the interaction with pUL39, whereas a weak interaction could still be observed. Amino acid sequence alignments showed that the interaction domains identified in PRV pUL39/pUL40 were relatively non-conserved among the selected RNR subunits in alphaherpesviruses HSV1, HSV2, HHV3(VZV), BHV1, EHV1 and DEV. However, they were relatively conserved among PRV, HSV1 and HSV2. Collectively, our findings provided some molecular targets for inhibition of pUL39-pUL40 interaction to antagonize viral replication in PRV infected hosts.
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Affiliation(s)
- Chuang Lyu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Wei-Dong Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Jin-Mei Peng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China
| | - Xue-Hui Cai
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Haping Road No.678, Harbin 150069, China.
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Stults AM, Smith GA. The Herpes Simplex Virus 1 Deamidase Enhances Propagation but Is Dispensable for Retrograde Axonal Transport into the Nervous System. J Virol 2019; 93:e01172-19. [PMID: 31462572 PMCID: PMC6819922 DOI: 10.1128/jvi.01172-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 08/19/2019] [Indexed: 02/06/2023] Open
Abstract
Upon replication in mucosal epithelia and transmission to nerve endings, capsids of herpes simplex virus 1 (HSV-1) travel retrogradely within axons to peripheral ganglia, where life-long latent infections are established. A capsid-bound tegument protein, pUL37, is an essential effector of retrograde axonal transport and also houses a deamidase activity that antagonizes innate immune signaling. In this report, we examined whether the deamidase of HSV-1 pUL37 contributes to the neuroinvasive retrograde axonal transport mechanism. We conclude that neuroinvasion is enhanced by the deamidase, but the critical contribution of pUL37 to retrograde axonal transport functions independently of this activity.IMPORTANCE Herpes simplex virus 1 invades the nervous system by entering nerve endings and sustaining long-distance retrograde axonal transport to reach neuronal nuclei in ganglia of the peripheral nervous system. The incoming viral particle carries a deamidase activity on its surface that antagonizes antiviral responses. We examined the contribution of the deamidase to the hallmark neuroinvasive property of this virus.
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Affiliation(s)
- Austin M Stults
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Gregory A Smith
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Thilakarathne DS, Coppo MJC, Hartley CA, Diaz-Méndez A, Quinteros JA, Fakhri O, Vaz PK, Devlin JM. Attenuated infectious laryngotracheitis virus vaccines differ in their capacity to establish latency in the trigeminal ganglia of specific pathogen free chickens following eye drop inoculation. PLoS One 2019; 14:e0213866. [PMID: 30921344 PMCID: PMC6438565 DOI: 10.1371/journal.pone.0213866] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/01/2019] [Indexed: 01/09/2023] Open
Abstract
Infectious laryngotracheitis (ILT) is a respiratory disease that affects chickens. It is caused by the alphaherpesvirus, infectious laryngotracheitis virus (ILTV). This virus undergoes lytic replication in the epithelial cells of the trachea and upper respiratory tract (URT) and establishes latent infection in the trigeminal ganglia (TG) and trachea. Live attenuated vaccines are widely used to control ILT. At least one of these vaccines can establish latent infections in chickens, but this has not been demonstrated for all vaccines. The aim of the current study was to determine the capacity of three commercially available vaccines (SA2, A20 and Serva) and a glycoprotein G deletion mutant vaccine candidate (ΔgG ILTV) to establish latent infection in the TG of specific pathogen free (SPF) chickens. Five groups of 7-day-old SPF chickens were eye-drop vaccinated with either one of the vaccine strains or mock-vaccinated with sterile media and followed until 20 or 21 days post-vaccination (dpv). ILTV DNA was detected at 20–21 dpv in the TG of 23/40 (57.5%) vaccinated SPF chickens (SA2 = 10/10; A20 = 6/10; Serva = 3/10; ΔgG = 4/10) by PCR, but virus could not be reactivated from TG co-cultivated with primary chicken embryo kidney cells. In the birds from which ILTV DNA was detected in the TG, ILTV DNA could not be detected in the URT or trachea of 3 birds in each of the SA2, A20 and Serva vaccinated groups, and in 4 birds in the ΔgG vaccinated group, indicating that these birds were latently infected in the absence of active lytic replication and virus shedding. Results from this study demonstrate the capacity of commercial ILTV vaccines to establish latent infections and underline their importance in the epidemiology of this disease.
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Affiliation(s)
- Dulari S. Thilakarathne
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| | - Mauricio J. C. Coppo
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Carol A. Hartley
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Andrés Diaz-Méndez
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - José A. Quinteros
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Omid Fakhri
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Paola K. Vaz
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Joanne M. Devlin
- Asia-Pacific Centre for Animal Health, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
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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. J Virol 2018; 92:JVI.01654-17. [PMID: 29321311 DOI: 10.1128/jvi.01654-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/03/2018] [Indexed: 12/20/2022] Open
Abstract
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 UL39mut), 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 ∼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.
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Analysis of Herpes Simplex Virus Reactivation in Explant Reveals a Method-Dependent Difference in Measured Timing of Reactivation. J Virol 2017. [PMID: 28637763 PMCID: PMC5533896 DOI: 10.1128/jvi.00848-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Herpes simplex virus (HSV) infection is widespread in the human population. Following orofacial infection, HSV establishes latency in innervating sensory neurons, primarily located in the trigeminal ganglia. A central feature of HSV pathogenesis is the ability to periodically reactivate in those neurons and be transported back to the body surface. Both transmission and disease, such as keratitis, encephalitis, and neurodegeneration, have been linked to reactivation. Despite invaluable insights obtained from model systems, interactions between viral and host functions that regulate reactivation are still incompletely understood. Various assays are used for measuring reactivation in animal models, but there have been limited comparisons between methods and the accuracy of detecting the timing of reactivation and the corresponding amount of infectious virus produced in the ganglia per reactivation event. Here, we directly compare two approaches for measuring reactivation in latently infected explanted ganglia by sampling media from the explanted cultures or by homogenization of the ganglia and compare the results to viral protein expression in the whole ganglia. We show that infectious virus detection by direct homogenization of explanted ganglia correlates with viral protein expression, but detection of infectious virus in medium samples from explanted cultures does not occur until extensive spread of virus is observed in the ganglia. The medium-sampling method is therefore not reflective of the initial timing of reactivation, and the additional variables influencing spread of virus in the ganglia should be considered when interpreting results obtained using this method. IMPORTANCE The development of treatments to prevent and/or treat HSV infection rely upon understanding viral and host factors that influence reactivation. Progress is dependent on experimental methods that accurately measure the frequency and timing of reactivation in latently infected neurons. In this study, two methods for detecting reactivation using the explant model are compared. We show through direct tissue homogenization that reactivation occurs much earlier than can be detected by the indirect method of sampling media from explanted cultures. Thus, the sampling method does not detect the initial timing of reactivation, and results obtained using this method are subject to additional variables with the potential to obscure reactivation outcomes.
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Impact of Type I Interferon on the Safety and Immunogenicity of an Experimental Live-Attenuated Herpes Simplex Virus 1 Vaccine in Mice. J Virol 2017; 91:JVI.02342-16. [PMID: 28122977 DOI: 10.1128/jvi.02342-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 01/17/2017] [Indexed: 12/12/2022] Open
Abstract
Viral fitness dictates virulence and capacity to evade host immune defenses. Understanding the biological underpinnings of such features is essential for rational vaccine development. We have previously shown that the live-attenuated herpes simplex virus 1 (HSV-1) mutant lacking the nuclear localization signal (NLS) on the ICP0 gene (0ΔNLS) is sensitive to inhibition by interferon beta (IFN-β) in vitro and functions as a highly efficacious experimental vaccine. Here, we characterize the host immune response and in vivo pathogenesis of HSV-1 0ΔNLS relative to its fully virulent parental strain in C57BL/6 mice. Additionally, we explore the role of type 1 interferon (IFN-α/β) signaling on virulence and immunogenicity of HSV-1 0ΔNLS and uncover a probable sex bias in the induction of IFN-α/β in the cornea during HSV-1 infection. Our data show that HSV-1 0ΔNLS lacks neurovirulence even in highly immunocompromised mice lacking the IFN-α/β receptor. These studies support the translational viability of the HSV-1 0ΔNLS vaccine strain by demonstrating that, while it is comparable to a virulent parental strain in terms of immunogenicity, HSV-1 0ΔNLS does not induce significant tissue pathology.IMPORTANCE HSV-1 is a common human pathogen associated with a variety of clinical presentations ranging in severity from periodic "cold sores" to lethal encephalitis. Despite the consistent failures of HSV subunit vaccines in clinical trials spanning the past 28 years, opposition to live-attenuated HSV vaccines predicated on unfounded safety concerns currently limits their widespread acceptance. Here, we demonstrate that a live-attenuated HSV-1 vaccine has great translational potential.
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Chiou HC, Kumura K, Hu A, Kerns KM, Coen DM. Penciclovir-Resistance Mutations in the Herpes Simplex Virus DNA Polymerase Gene. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029500600501] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Penciclovir is the active form of the orally available prodrug famciclovir, which is entering clinical use for herpesvirus infections. Like aciclovir, penciclovir is an acyclic guanosine analogue that is phosphorylated by viral thymidine kinase and whose triphosphate can inhibit viral DNA polymerase. We tested several well-characterized herpes simplex virus mutants with aciclovir-resistance mutations in the viral DNA polymerase gene for altered sensitivity to penciclovir. The mutants varied in their susceptibilities to penciclovir with one exhibiting 2-fold hypersensitivity, one marginal resistance and three about 3-fold resistance. Marker rescue and DNA sequencing analyses mapped the penciclovir-resistance mutation of one mutant, AraA r7, to a single base change that alters a glycine to a cysteine at residue 841 within conserved region III of α-like DNA polymerases. The results have implications for the mechanism of selective action of penciclovir, for the potential for development of resistance in the clinic, and for the substrate recognition properties of herpes simplex virus DNA polymerase.
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Affiliation(s)
- Henry C. Chiou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Keiko Kumura
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - André Hu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kelvin M. Kerns
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Donald M. Coen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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10
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Terrell SL, Pesola JM, Coen DM. Roles of conserved residues within the pre-NH2-terminal domain of herpes simplex virus 1 DNA polymerase in replication and latency in mice. J Gen Virol 2014; 95:940-947. [PMID: 24413420 DOI: 10.1099/vir.0.061903-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The catalytic subunit of the herpes simplex virus 1 DNA polymerase (HSV-1 Pol) is essential for viral DNA synthesis and production of infectious virus in cell culture. While mutations that affect 5'-3' polymerase activity have been evaluated in animal models of HSV-1 infection, mutations that affect other functions of HSV-1 Pol have not. In a previous report, we utilized bacterial artificial chromosome technology to generate defined HSV-1 pol mutants with lesions in the previously uncharacterized pre-NH2-terminal domain. We found that the extreme N-terminal 42 residues (deletion mutant polΔN43) were dispensable for replication in cell culture, while residues 44-49 (alanine-substitution mutant polA6) were required for efficient viral DNA synthesis and production of infectious virus. In this study, we sought to address the importance of these conserved elements in viral replication in a mouse corneal infection model. Mutant virus polΔN43 exhibited no meaningful defect in acute or latent infection despite strong conservation of residues 1-42 with HSV-2 Pol. The polA6 mutation caused a modest defect in replication at the site of inoculation, and was severely impaired for ganglionic replication, even at high inocula that permitted efficient corneal replication. Additionally, the polA6 mutation resulted in reduced latency establishment and subsequent reactivation. Moreover, we found that the polA6 replication defect in cultured cells was exacerbated in resting cells as compared to dividing cells. These results reveal an important role for the conserved motif at residues 44-49 of HSV-1 Pol for ganglionic viral replication.
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Affiliation(s)
- Shariya L Terrell
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Jean M Pesola
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Donald M Coen
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
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11
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Herpes simplex virus 1 ICP22 but not US 1.5 is required for efficient acute replication in mice and VICE domain formation. J Virol 2013; 87:13510-9. [PMID: 24089574 DOI: 10.1128/jvi.02424-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The herpes simplex virus 1 (HSV-1) immediate-early protein, infected cell protein 22 (ICP22), is required for efficient replication in restrictive cells, for virus-induced chaperone-enriched (VICE) domain formation, and for normal expression of a subset of viral late proteins. Additionally, ICP22 is important for optimal acute viral replication in vivo. Previous studies have shown that the US1 gene that encodes ICP22, produces an in-frame, N-terminally truncated form of ICP22, known as US1.5. To date, studies conducted to characterize the functions of ICP22 have not separated its functions from those of US1.5. To determine the individual roles of ICP22 and US1.5, we made viral mutants that express either ICP22 with an M90A mutation in the US1.5 initiation codon (M90A) or US1.5 with three stop codons introduced upstream of the US1.5 start codon (3×stop). Our studies showed that, in contrast to M90A, 3×stop was unable to replicate efficiently in the eyes and trigeminal ganglia of mice during acute infection, to efficiently establish a latent infection, or to induce VICE domain formation and was only mildly reduced in its replication in restrictive HEL-299 cells and murine embryonic fibroblasts (MEFs). Both mutants enhanced the expression of the late viral proteins virion host shutoff (vhs) and glycoprotein C (gC) and inhibited viral gene expression mediated by HSV-1 infected cell protein 0 (ICP0). When we tested our mutants' sensitivity to type I interferon (beta interferon [IFN-β]) in restrictive cells, we noticed that the plating of the ICP22 null (d22) and 3×stop mutants was reduced by the addition of IFN-β. Overall, our data suggest that US1.5 partially complements the functions of ICP22.
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12
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Rice SA, Davido DJ. HSV-1 ICP22: hijacking host nuclear functions to enhance viral infection. Future Microbiol 2013; 8:311-21. [PMID: 23464370 DOI: 10.2217/fmb.13.4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During its productive infection, HSV-1 dramatically remodels the architecture and physiology of the host cell nucleus. The immediate-early proteins, the first viral proteins to be expressed during infection, are key players in this process. Here, we review the known properties and functions of immediate-early protein ICP22. Although this polypeptide has received less attention than other immediate-early proteins, the published evidence indicates that it mediates several striking changes to important host nuclear systems, including those involved in RNA polymerase II transcription, cell cycle regulation and protein quality control. Recent genetic analyses suggest that these alterations can promote HSV-1 productive infection. Thus, future work on ICP22 is likely to reveal novel mechanisms by which herpesviruses, and possibly other DNA viruses, manipulate the host cell nucleus to enhance their replication.
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Affiliation(s)
- Stephen A Rice
- Department of Microbiology, University of Minnesota, MMC 196, 420 Delaware Avenue S, Minneapolis, MN 55455, USA.
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13
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Abstract
This overview describes the considerations involved in the preparation and use of a herpes simplex virus type 1 (HSV-1) amplicon as a vector for gene transfer into neurons. Strategies for gene delivery into neurons, either to study the molecular biology of brain function or for gene therapy, must utilize vectors that persist stably in postmitotic cells and that can be targeted both spatially and temporally in the nervous system in vivo. This unit describes the biology of HSV-1 along with a discussion covering development of amplicon and genomic HSV-1 vectors. Advantages and disadvantages of current HSV-1 vectors are presented, and HSV-1 vectors are compared with other vectors for gene transfer into neurons.
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Affiliation(s)
- Rachael L Neve
- Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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14
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Nicoll MP, Proença JT, Efstathiou S. The molecular basis of herpes simplex virus latency. FEMS Microbiol Rev 2012; 36:684-705. [PMID: 22150699 PMCID: PMC3492847 DOI: 10.1111/j.1574-6976.2011.00320.x] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Revised: 11/24/2011] [Accepted: 11/28/2011] [Indexed: 12/11/2022] Open
Abstract
Herpes simplex virus type 1 is a neurotropic herpesvirus that establishes latency within sensory neurones. Following primary infection, the virus replicates productively within mucosal epithelial cells and enters sensory neurones via nerve termini. The virus is then transported to neuronal cell bodies where latency can be established. Periodically, the virus can reactivate to resume its normal lytic cycle gene expression programme and result in the generation of new virus progeny that are transported axonally back to the periphery. The ability to establish lifelong latency within the host and to periodically reactivate to facilitate dissemination is central to the survival strategy of this virus. Although incompletely understood, this review will focus on the mechanisms involved in the regulation of latency that centre on the functions of the virus-encoded latency-associated transcripts (LATs), epigenetic regulation of the latent virus genome and the molecular events that precipitate reactivation. This review considers current knowledge and hypotheses relating to the mechanisms involved in the establishment, maintenance and reactivation herpes simplex virus latency.
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Affiliation(s)
- Michael P Nicoll
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, UK
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15
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Sustained CD8+ T cell memory inflation after infection with a single-cycle cytomegalovirus. PLoS Pathog 2011; 7:e1002295. [PMID: 21998590 PMCID: PMC3188546 DOI: 10.1371/journal.ppat.1002295] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 08/16/2011] [Indexed: 02/03/2023] Open
Abstract
Cytomegalovirus (CMV) is a β-herpesvirus that establishes a lifelong latent or persistent infection. A hallmark of chronic CMV infection is the lifelong persistence of large numbers of virus-specific CD8+ effector/effector memory T cells, a phenomenon called “memory inflation”. How the virus continuously stimulates these T cells without being eradicated remains an enigma. The prevailing view is that CMV establishes a low grade “smoldering” infection characterized by tiny bursts of productive infection which are rapidly extinguished, leaving no detectable virus but replenishing the latent pool and leaving the immune system in a highly charged state. However, since abortive reactivation with limited viral gene expression is known to occur commonly, we investigated the necessity for virus reproduction in maintaining the inflationary T cell pool. We inhibited viral replication or spread in vivo using two different mutants of murine CMV (MCMV). First, famcyclovir blocked the replication of MCMV encoding the HSV Thymidine Kinase gene, but had no impact on the CD8+ T cell memory inflation once the infection was established. Second, MCMV that lacks the essential glycoprotein L, and thus is completely unable to spread from cell to cell, also drove memory inflation if the virus was administered systemically. Our data suggest that CMV which cannot spread from the cells it initially infects can repeatedly generate viral antigens to drive memory inflation without suffering eradication of the latent genome pool. Cytomegalovirus (CMV) establishes life-long, asymptomatic infections in healthy people. Ongoing immune surveillance prevents viral disease but also results in the accumulation of large numbers of virus-specific T cells. The mechanisms by which the virus persists while stimulating such strong immune responses are unknown. We and others had hypothesized that periodic viral replication and spread to neighboring cells allowed CMV to replenish the pool of infected cells while stimulating virus-specific T cells to accumulate. In this manuscript, we have tested this model by blocking the replication or spread of murine cytomegalovirus (MCMV) and found, surprisingly, that accumulation of virus-specific T cells occurs independently of viral replication. Moreover, these T cells developed the terminal differentiated phenotype that is indicative of repeated antigenic stimulation. Thus, these data suggest that CMV can remain active and continuously stimulate the immune system, while avoiding immune-mediated clearance, without the capacity to spread from cell to cell.
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16
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Herpes simplex virus 1 ICP0 phosphorylation site mutants are attenuated for viral replication and impaired for explant-induced reactivation. J Virol 2011; 85:12631-7. [PMID: 21937654 DOI: 10.1128/jvi.05661-11] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In cell culture experiments, phosphorylation appears to be a critical regulator of the herpes simplex virus 1 (HSV-1) immediate-early (IE) protein, ICP0, which is an E3 ubiquitin ligase that transactivates viral gene expression. Three major regions of phosphorylation in ICP0 (amino acids 224 to 232, 365 to 371, and 508 to 518) have been identified, and mutant viruses that block phosphorylation sites within each region (termed Phos 1, 2, and 3, respectively) have been constructed. Previous studies indicated that replication of Phos 1 is significantly reduced compared to that of wild-type virus in cell culture (C. Boutell, et al., J. Virol. 82:10647-10656, 2008). To determine the effects these phosphorylation site mutations have on the viral life cycle in vivo, mice were ocularly infected with wild-type HSV-1, the Phos mutants, or their marker rescue counterparts. Subsequently, viral replication, establishment of latency, and viral explant-induced reactivation of these viruses were examined. Relative to wild-type virus, Phos 1 eye titers were reduced as much as 7- and 18-fold on days 1 and 5 postinfection, respectively. Phos 2 eye titers showed a decrease of 6-fold on day 1 postinfection. Titers of Phos 1 and 2 trigeminal ganglia were reduced as much as 16- and 20-fold, respectively, on day 5 postinfection. Additionally, the reactivation efficiencies of Phos 1 and 2 were impaired relative to wild-type HSV-1, although both viruses established wild-type levels of latency in vivo. The acute replication, latency, and reactivation phenotypes of Phos 3 were similar to those of wild-type HSV-1. We conclude from these studies that phosphorylation is likely a key modulator of ICP0's biological activities in a mouse ocular model of HSV-1 infection.
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17
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Abstract
Primary infection by varicella zoster virus (VZV) typically results in childhood chickenpox, at which time latency is established in the neurons of the cranial nerve, dorsal root and autonomic ganglia along the entire neuraxis. During latency, the histone-associated virus genome assumes a circular episomal configuration from which transcription is epigenetically regulated. The lack of an animal model in which VZV latency and reactivation can be studied, along with the difficulty in obtaining high-titer cell-free virus, has limited much of our understanding of VZV latency to descriptive studies of ganglia removed at autopsy and analogy to HSV-1, the prototype alphaherpesvirus. However, the lack of miRNA, detectable latency-associated transcript and T-cell surveillance during VZV latency highlight basic differences between the two neurotropic herpesviruses. This article focuses on VZV latency: establishment, maintenance and reactivation. Comparisons are made with HSV-1, with specific attention to differences that make these viruses unique human pathogens.
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Affiliation(s)
| | - Aamir Shahzad
- Department for Biomolecular Structural Chemistry Max F. Perutz Laboratories, University of Vienna, Austria
| | - Randall J Cohrs
- Author for correspondence: University of Colorado Denver Medical School, Aurora, CO, USA, Tel.: +1 303 742 4325
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18
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Haenchen SD, Utter JA, Bayless AM, Dobrowsky RT, Davido DJ. Role of a cdk5-associated protein, p35, in herpes simplex virus type 1 replication in vivo. J Neurovirol 2011; 16:405-9. [PMID: 20839922 DOI: 10.3109/13550284.2010.513030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Previous studies have shown that herpes simplex virus type 1 (HSV-1) replication is inhibited by the cyclin-dependent kinase (cdk) inhibitor roscovitine. One roscovitine-sensitive cdk that functions in neurons is cdk5, which is activated in part by its binding partner, p35. Because HSV establishes latent infections in sensory neurons, we sought to determine the role p35 plays in HSV-1 replication in vivo. For these studies, wild-type (wt) and p35−/− mice were infected with HSV-1 using the mouse ocular model of HSV latency and reactivation. The current results indicate that p35 is an important determinant of viral replication in vivo.
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Affiliation(s)
- Steve D Haenchen
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas 66045, USA
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19
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Thompson RL, Sawtell NM. Therapeutic implications of new insights into the critical role of VP16 in initiating the earliest stages of HSV reactivation from latency. Future Med Chem 2010; 2:1099-105. [PMID: 21426158 PMCID: PMC3087177 DOI: 10.4155/fmc.10.197] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Reactivation of herpes simplex virus (HSV) is a leading cause of fatal encephalitis in the USA and recurrent herpetic keratitis is a major infectious cause of blindness. There is no effective vaccine and no cure for HSV latency. While current antiviral drugs reduce viral replication, none prevent the initiation of reactivation in the nervous system and, thus, chronic inflammatory damage proceeds. The discovery that HSV VP16 is necessary for the exit from latency represents the first potential target for preventing the chronic inflammatory insult associated with HSV reactivation. Blocking VP16 transactivation would reduce the spread of the virus in the population and, importantly, presumably reduce or prevent the pathological long term chronic inflammation in the nervous system.
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Affiliation(s)
- Richard L Thompson
- Department of Molecular Genetics, Microbiology, and Biochemistry, University of Cincinnati, School of Medicine, Cincinnati, OH 45267–0524, USA
| | - Nancy M Sawtell
- Department of Pediatrics, Division of Infectious Diseases, Cincinnati, Children’s Hospital Medical Center, Cincinnati, Ohio 45229–3039, USA
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20
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Towards an understanding of the herpes simplex virus type 1 latency-reactivation cycle. Interdiscip Perspect Infect Dis 2010; 2010:262415. [PMID: 20169002 PMCID: PMC2822239 DOI: 10.1155/2010/262415] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Accepted: 11/30/2009] [Indexed: 12/17/2022] Open
Abstract
Infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system. Recurrent ocular shedding can lead to corneal scarring and vision loss making HSV-1 a leading cause of corneal blindness due to an infectious agent. The primary site of HSV-1 latency is sensory neurons within trigeminal ganglia. Periodically, reactivation from latency occurs resulting in virus transmission and recurrent disease. During latency, the latency-associated transcript (LAT) is abundantly expressed. LAT expression is important for the latency-reactivation cycle in animal models, in part, because it inhibits apoptosis, viral gene expression, and productive infection. A novel transcript within LAT coding sequences (AL3) and small nonprotein coding RNAs are also expressed in trigeminal ganglia of latently infected mice. In this review, an update of viral factors that are expressed during latency and their potential roles in regulating the latency-reactivation cycle is discussed.
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21
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Thompson RL, Preston CM, Sawtell NM. De novo synthesis of VP16 coordinates the exit from HSV latency in vivo. PLoS Pathog 2009; 5:e1000352. [PMID: 19325890 PMCID: PMC2654966 DOI: 10.1371/journal.ppat.1000352] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2008] [Accepted: 02/26/2009] [Indexed: 12/26/2022] Open
Abstract
The mechanism controlling the exit from herpes simplex virus latency (HSV) is of
central importance to recurrent disease and transmission of infection, yet
interactions between host and viral functions that govern this process remain
unclear. The cascade of HSV gene transcription is initiated by the
multifunctional virion protein VP16, which is expressed late in the viral
replication cycle. Currently, it is widely accepted that VP16 transactivating
function is not involved in the exit from latency. Utilizing the mouse ocular
model of HSV pathogenesis together with genetically engineered viral mutants and
assays to quantify latency and the exit from latency at the single neuron level,
we show that in vivo (i) the VP16 promoter confers distinct regulation critical
for viral replication in the trigeminal ganglion (TG) during the acute phase of
infection and (ii) the transactivation function of VP16 (VP16TF) is uniquely
required for the exit from latency. TG neurons latently infected with the VP16TF
mutant in1814 do not express detectable viral proteins following stress, whereas
viruses with mutations in the other major viral transcription regulators ICP0
and ICP4 do exit the latent state. Analysis of a VP16 promoter/reporter mutant
in the background of in1814 demonstrates that the VP16 promoter is activated in
latently infected neurons following stress in the absence of other viral
proteins. These findings support the novel hypothesis that de novo expression of
VP16 regulates entry into the lytic program in neurons at all phases of the
viral life cycle. HSV reactivation from latency conforms to a model in which
stochastic derepression of the VP16 promoter and expression of VP16 initiates
entry into the lytic cycle. Herpes simplex virus (HSV) establishes life-long latent infections in sensory
neurons of the human host. Periodically, HSV exits latency in an infected neuron
and is transported to the body surface where it replicates, leading to recurrent
disease and infection of new hosts. We do not currently understand how entry
into the lytic cycle is blocked in neurons and latency is established. Nor do we
know how, at some time in the future, the lytic program becomes activated in the
one or two latently infected neurons which characterize a reactivation event. In
tissue culture cells, and by analogy in cells at the body surface, the HSV
replication program is initiated by the interaction of a virion protein, VP16
(brought in with the virus as a protein), with host cell factors. Here we show
that the de novo synthesis of VP16 is required for efficient viral replication
during the acute phase of infection in neurons. This indicates that latency is
favored because VP16 may not be transported efficiently to the nerve cell
nucleus. Once latency is established, the de novo expression of VP16 is an
absolute and very early requirement for the exit from the latent state. Our data
support a model of HSV reactivation in which the stochastic derepression of the
VP16 promoter and resulting expression of VP16 starts the viral lytic
program.
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Affiliation(s)
- Richard L. Thompson
- Department of Molecular Genetics, Microbiology, and Biochemistry,
University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of
America
| | - Chris M. Preston
- Medical Research Council Virology Unit, Glasgow, Scotland, United
Kingdom
| | - Nancy M. Sawtell
- Department of Pediatrics, Division of Infectious Diseases, Cincinnati
Children's Hospital Medical Center, Cincinnati, Ohio, United States of
America
- * E-mail:
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22
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CD8(+) T-cell attenuation of cutaneous herpes simplex virus infection reduces the average viral copy number of the ensuing latent infection. Immunol Cell Biol 2008; 86:666-75. [PMID: 18607387 DOI: 10.1038/icb.2008.47] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
During an initial encounter with herpes simplex virus type 1 (HSV-1) it takes several days for an adaptive immune response to develop and for herpes-specific CD8(+) T cells to infiltrate sites of infection. By this time the virus has firmly established itself within the innervating sensory nervous system where it then persists indefinitely. Preventing the establishment of viral latency would require blocking the skin to nervous system transmission of the virus. We wished to examine if CD8(+) T cells present early during acute HSV-1 infection could block this transmission. We show that effector CD8(+) T cells failed to prevent the establishment of HSV latency even when present prior to infection. This lack of blocking likely reflects the delayed infiltration of the CD8(+) T cells into the infected skin. Examination of the kinetics of HSV-1 infection highlighted the rapidity at which the virus infects the sensory ganglia and singled out early viral replication within the skin as an important factor in determining the magnitude of the ensuing latent infection. Though unable to prevent the establishment of latency, CD8(+) T cells could reduce the average viral copy number of the residual latent infection by dampening the skin infection and thus limiting the skin-to-nerve transmission of virus.
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23
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Neve RL, Lim F. Overview of gene delivery into cells using HSV-1-based vectors. ACTA ACUST UNITED AC 2008; Chapter 4:Unit 4.12. [PMID: 18428476 DOI: 10.1002/0471142301.ns0100s06] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This overview describes the considerations involved in the preparation and use of herpes simplex virus type 1 (HSV-1) as a vector for gene transfer into neurons. Strategies for gene delivery into neurons, either to study the molecular biology of brain function or for gene therapy, must utilize vectors that persist stably in postmitotic cells and that can be targeted both spatially and temporally in the nervous system in vivo. This unit describes the biology of HSV-1 along with a discussion covering development of amplicon and genomic HSV-1 vectors. Advantages and disadvantages of current HSV-1 vectors are presented, and HSV-1 vectors are compared with other vectors for gene transfer into neurons.
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Affiliation(s)
- R L Neve
- Harvard Medical School & McLean Hospital, Belmont, Massachusetts, USA
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24
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Coen DM. Quantitation of rare DNAs by PCR. ACTA ACUST UNITED AC 2008; Chapter 10:10.21.1-10.21.8. [PMID: 18432686 DOI: 10.1002/0471142735.im1021s24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This unit presents a protocol that uses the polymerase chain reaction (PCR) to quantitate the numbers of a particular DNA sequence from 1 to 20,000 molecules per sample. In addition, it helps assess the presence of contaminating sequences, the bane of this kind of procedure. The DNA of interest is prepared and its concentration is determined. A known amount of this DNA is then mixed with two sets of oligonucleotide primers, one set specific for the DNA of interest (e.g., a virus) and the other set specific for an internal control (e.g., a single-copy gene encoded by the host organism). The sequences between the primers are amplified, electrophoresed on a gel, transferred to a filter, and probed with oligonucleotides specific for each amplified product. The amounts of the amplified products from the DNA of interest can then be quantitated by comparison to the internal control. For simplicity, the protocol is written in terms of quantitating viral DNA molecules relative to host cellular sequences; however, it can be adapted readily for other applications.
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Affiliation(s)
- D M Coen
- Harvard Medical School, Boston, Massachusetts, USA
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25
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Sawtell NM. Preparation of single cells from solid tissues for analysis by PCR. ACTA ACUST UNITED AC 2008; Chapter 25:Unit 25A.2. [PMID: 18265311 DOI: 10.1002/0471142727.mb25a02s58] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This unit details a protocol for the separation of solid tissues into single cell suspensions for subsequent analysis of nucleic acids and protein. Tissues are fixed in situ by perfusion, which terminates cell processes and thus changes that would accompany dissociating the living tissue. The procedure is particularly useful when the cell type of interest represents a minor population relative to other cells types in the tissue. Once separated, individual cells or groups of a particular cell type can then be analyzed using PCR strategies. The procedure can also be adapted to allow the quantification of the number of cells within a tissue containing specific nucleic acid sequences, for example, a particular viral DNA or RNA sequence.
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Affiliation(s)
- N M Sawtell
- Children's Hospital Medical Center, Cincinnati, Ohio, USA
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26
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van Lint AL, Torres-Lopez E, Knipe DM. Immunization with a replication-defective herpes simplex virus 2 mutant reduces herpes simplex virus 1 infection and prevents ocular disease. Virology 2007; 368:227-31. [PMID: 17915278 PMCID: PMC2099303 DOI: 10.1016/j.virol.2007.08.030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Revised: 07/09/2007] [Accepted: 08/27/2007] [Indexed: 11/24/2022]
Abstract
Ocular infections with herpes simplex virus 1 can lead to corneal scarring and blindness, with herpes keratitis being the major infectious cause of blindness. There is currently no clinically approved vaccine and nearly all developmental vaccines are targeted against HSV-2 and genital herpes. We tested the ability of an HSV-2 replication-defective virus, a genital herpes vaccine candidate, to protect against HSV-1 corneal infection. Immunization with HSV-2 dl5-29 reduced viral replication in the cornea, prevented ocular disease and reduced latent infection by the HSV-1 strain. Therefore, this HSV-2 replication-defective mutant strain may have applications for prevention of herpes keratitis and genital herpes due to HSV-1 infection.
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Affiliation(s)
| | | | - David M. Knipe
- * Corresponding author: Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Ave, Boston, MA 02115. , Phone: 617 432 1934, Fax: 617 432 0223
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27
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Wang K, Mahalingam G, Hoover SE, Mont EK, Holland SM, Cohen JI, Straus SE. Diverse herpes simplex virus type 1 thymidine kinase mutants in individual human neurons and Ganglia. J Virol 2007; 81:6817-26. [PMID: 17459924 PMCID: PMC1933309 DOI: 10.1128/jvi.00166-07] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mutations in the thymidine kinase gene (tk) of herpes simplex virus type 1 (HSV-1) explain most cases of virus resistance to acyclovir (ACV) treatment. Mucocutaneous lesions of patients with ACV resistance contain mixed populations of tk mutant and wild-type virus. However, it is unknown whether human ganglia also contain mixed populations since the replication of HSV tk mutants in animal neurons is impaired. Here we report the detection of mutated HSV tk sequences in human ganglia. Trigeminal and dorsal root ganglia were obtained at autopsy from an immunocompromised woman with chronic mucocutaneous infection with ACV-resistant HSV-1. The HSV-1 tk open reading frames from ganglia were amplified by PCR, cloned, and sequenced. tk mutations were detected in a seven-G homopolymer region in 11 of 12 ganglia tested, with clonal frequencies ranging from 4.2 to 76% HSV-1 tk mutants per ganglion. In 8 of 11 ganglia, the mutations were heterogeneous, varying from a deletion of one G to an insertion of one to three G residues, with the two-G insertion being the most common. Each ganglion had its own pattern of mutant populations. When individual neurons from one ganglion were analyzed by laser capture microdissection and PCR, 6 of 14 HSV-1-positive neurons were coinfected with HSV tk mutants and wild-type virus, 4 of 14 were infected with wild-type virus alone, and 4 of 14 were infected with tk mutant virus alone. These data suggest that diverse tk mutants arise independently under drug selection and establish latency in human sensory ganglia alone or together with wild-type virus.
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Affiliation(s)
- Kening Wang
- Medical Virology Section, Laboratory of Clinical Infectious Disease, NIAID/NIH, Building 10, Room 11N-234, 10 Center Dr., Bethesda, MD 20892, USA.
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28
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Sawtell NM, Thompson RL, Haas RL. Herpes simplex virus DNA synthesis is not a decisive regulatory event in the initiation of lytic viral protein expression in neurons in vivo during primary infection or reactivation from latency. J Virol 2007; 80:38-50. [PMID: 16352529 PMCID: PMC1317510 DOI: 10.1128/jvi.80.1.38-50.2006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The herpes simplex virus genome can enter a repressed transcriptional state (latency) in sensory neurons of the host nervous system. Although reduced permissiveness of the neuronal environment is widely accepted as a causal factor, the molecular pathway(s) directing and maintaining the viral genome in the latent state remains undefined. Over the past decade, the field has been strongly influenced by the observations of Kosz-Vnenchak et al., which have been interpreted to indicate that, in sensory neurons in vivo, a critical level of viral DNA synthesis within the neuron is required for sufficient viral immediate-early (IE) and early (E) gene expression (M. Kosz-Vnenchak, J. Jacobson, D. M. Coen, and D. M. Knipe, J. Virol. 67:5383-5393, 1993). The levels of IE and E genes are, in turn, thought to regulate the decision to enter the lytic cycle or latency. We have reexamined this issue using new strategies for in situ detection and quantification of viral gene expression in whole tissues. Our results using thymidine kinase-null and rescued mutants as well as wild-type strains in conjunction with viral DNA synthesis blockers demonstrate that (i) despite inhibition of viral DNA replication, many neurons express lytic viral proteins, including IE proteins, during acute infection in the ganglion; (ii) at early times postinoculation, the number of neurons expressing viral proteins in the ganglion is not reduced by inhibition of viral DNA replication; and (iii) following a reactivation stimulus, the numbers of neurons and apparent levels of lytic viral proteins, including IE proteins, are not reduced by inhibition of viral DNA replication. We conclude that viral DNA replication in the neuron per se does not regulate IE gene expression or entry into the lytic cycle.
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Affiliation(s)
- N M Sawtell
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229-3039, USA.
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29
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Chen SH, Lin YW, Griffiths A, Huang WY, Chen SH. Competition and complementation between thymidine kinase-negative and wild-type herpes simplex virus during co-infection of mouse trigeminal ganglia. J Gen Virol 2006; 87:3495-3502. [PMID: 17098963 DOI: 10.1099/vir.0.82223-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Laboratory strains of herpes simplex virus lacking thymidine kinase (TK) cannot replicate acutely to detectable levels in mouse trigeminal ganglia and do not reactivate from latency. However, many pathogenic clinical isolates that are resistant to the antiviral drug acyclovir are heterogeneous populations of TK-negative (TK(-)) and TK-positive (TK(+)) viruses. To recapitulate this in vivo, mice were infected with mixtures of wild-type virus and a recombinant TK(-) mutant in various ratios. Following co-infection, the replication, number of latent viral genomes and reactivation efficiency of TK(+) virus in trigeminal ganglia were reduced in a manner related to the amount of TK(-) virus in the inoculum. TK(+) virus did not always complement the acute replication or increase the number of latent viral genomes of TK(-) mutant in mouse ganglia. Even so, TK(+) virus could still confer the pathogenic phenotype to a TK(-) mutant, somehow providing sufficient TK activity in trans to permit a TK(-) mutant to reactivate from latently infected ganglia.
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Affiliation(s)
- Shih-Heng Chen
- Institute of Basic Medical Sciences and Department of Microbiology and Immunology, Medical College, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China
| | - Yu-Wen Lin
- Institute of Basic Medical Sciences and Department of Microbiology and Immunology, Medical College, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China
| | - Anthony Griffiths
- Department of Virology and Immunology, Southwest Foundation for Biomedical Research, 7620 NW Loop 410, San Antonio, TX 78227, USA
| | - Wen-Yen Huang
- Institute of Basic Medical Sciences and Department of Microbiology and Immunology, Medical College, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China
| | - Shun-Hua Chen
- Institute of Basic Medical Sciences and Department of Microbiology and Immunology, Medical College, National Cheng Kung University, Tainan 70101, Taiwan, Republic of China
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Orlando JS, Balliet JW, Kushnir AS, Astor TL, Kosz-Vnenchak M, Rice SA, Knipe DM, Schaffer PA. ICP22 is required for wild-type composition and infectivity of herpes simplex virus type 1 virions. J Virol 2006; 80:9381-90. [PMID: 16973544 PMCID: PMC1617265 DOI: 10.1128/jvi.01061-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The immediate-early regulatory protein ICP22 is required for efficient replication of herpes simplex virus type 1 in some cell types (permissive) but not in others (restrictive). In mice infected via the ocular route, the pathogenesis of an ICP22- virus, 22/n199, was altered relative to that of wild-type virus. Specifically, tear film titers of 22/n199-infected mice were significantly reduced at 3 h postinfection relative to those of mice infected with wild-type virus. Further, 22/n199 virus titers were below the level of detection in trigeminal ganglia (TG) during the first 9 days postinfection. On day 30 postinfection, TG from 22/n199-infected mice contained reduced viral genome loads and exhibited reduced expression of latency-associated transcripts and reduced reactivation efficiency relative to TG from wild-type virus-infected mice. Notably, the first detectable alteration in the pathogenesis of 22/n199 in these tests occurred in the eye prior to the onset of nascent virus production. Thus, ICP22- virions appeared to be degraded, cleared, or adsorbed more rapidly than wild-type virions, implying potential differences in the composition of the two virion types. Analysis of the protein composition of purified extracellular virions indicated that ICP22 is not a virion component and that 22/n199 virions sediment at a reduced density relative to wild-type virions. Although similar to wild-type virions morphologically, 22/n199 virions contain reduced amounts of two gamma2 late proteins, US11 and gC, and increased amounts of two immediate-early proteins, ICP0 and ICP4, as well as protein species not detected in wild-type virions. Although ICP22- viruses replicate to near-wild-type levels in permissive cells, the virions produced in these cells are biochemically and physically different from wild-type virions. These virion-specific differences in ICP22- viruses add a new level of complexity to the functional analysis of this immediate-early viral regulatory protein.
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Affiliation(s)
- Joseph S Orlando
- Department of Microbiology and Molecular Genetics, Harvard Medical School at the Beth Israel Deaconess Medical Center, 330 Brookline Avenue, RN 123, Boston, MA 02215, USA
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31
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Pesola JM, Zhu J, Knipe DM, Coen DM. Herpes simplex virus 1 immediate-early and early gene expression during reactivation from latency under conditions that prevent infectious virus production. J Virol 2005; 79:14516-25. [PMID: 16282451 PMCID: PMC1287588 DOI: 10.1128/jvi.79.23.14516-14525.2005] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 09/12/2005] [Indexed: 01/20/2023] Open
Abstract
The program of gene expression exhibited by herpes simplex virus during productive infection of cultured cells is well established; however, less is known about the regulatory controls governing reactivation from latency in neurons. One difficulty in examining gene regulation during reactivation lies in distinguishing between events occurring in initial reactivating cells versus events occurring in secondarily infected cells. Thus, two inhibitors were employed to block production of infectious virus: acyclovir, which inhibits viral DNA synthesis, and WAY-150138, which permits viral DNA synthesis but inhibits viral DNA encapsidation. Latently infected murine ganglia were explanted in the presence of either inhibitor, and then amounts of RNA, DNA, or infectious virus were quantified. In ganglia explanted for 48 h, the levels of five immediate-early and early RNAs did not exhibit meaningful differences between acyclovir and WAY-150138 treatments when analyzed by in situ hybridization or quantitative reverse transcription-PCR. However, comparative increases in viral DNA and RNA content in untreated ganglia suggested that virus was produced before 48 h postexplant. This was confirmed by the detection of infectious virus as early as 14 h postexplant. Together, these results suggest that high levels of viral gene expression at 48 h postexplant are due largely to the production of infectious virus and subsequent spread through the tissue. These results lead to a reinterpretation of previous results indicating a role for DNA replication in immediate-early and early viral gene expression; however, it remains possible that viral gene expression is regulated differently in neurons than in cultured cells.
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Affiliation(s)
- Jean M Pesola
- Department of Biological Chemistry, Harvard Medical School, Boston, MA 02115, USA
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32
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Cohen JI, Krogmann T, Ross JP, Pesnicak L, Prikhod'ko EA. Varicella-zoster virus ORF4 latency-associated protein is important for establishment of latency. J Virol 2005; 79:6969-75. [PMID: 15890936 PMCID: PMC1112154 DOI: 10.1128/jvi.79.11.6969-6975.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Varicella-zoster virus (VZV) encodes at least six genes that are expressed during latency. One of the genes, ORF4, encodes an immediate-early protein that is present in the virion tegument. ORF4 RNA and protein have been detected in latently infected human ganglia. We have constructed a VZV mutant deleted for ORF4 and have shown that the gene is essential for replication in vitro. The ORF4 mutant virus could be propagated when grown in cells infected with baculovirus expressing the ORF4 protein under the human cytomegalovirus immediate-early promoter. In contrast, the VZV ORF4 deletion mutant could not be complemented in cells expressing herpes simplex virus type 1 (HSV-1) ICP27, the homolog of ORF4. Cells infected with baculovirus expressing ORF4 did not complement an HSV-1 ICP27 deletion mutant. VZV-infected cotton rats have been used as a model for latency; viral DNA and latency-associated transcripts are expressed in dorsal root ganglia 1 month or more after experimental infection. Cotton rats inoculated with VZV lacking ORF4 showed reduced frequency of latency compared to animals infected with the parental or ORF4-rescued virus. Thus, in addition to VZV ORF63, which was previously shown to be critical for efficient establishment of latency, ORF4 is also important for latent infection.
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Affiliation(s)
- Jeffrey I Cohen
- Medical Virology Section, Laboratory of Clinical Infectious Diseases, National Institutes of Health, 10 Center Drive, Bethesda, MD 20892, USA.
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Parrott ML, Ward SJ, Taggart DA. Multiple paternity and communal maternal care in the feathertail glider (Acrobates pygmaeus). AUST J ZOOL 2005. [DOI: 10.1071/zo04025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It has been predicted, on the basis of morphological and behavioural evidence, that female feathertail gliders (Acrobates pygmaeus) will mate with multiple males within a single oestrus and that multiple paternity may occur in their litters. To determine whether feathertail glider litters are sired by multiple males, DNA collected from 10 litters and their mothers was tested for hereditary polymorphisms. The techniques used to evaluate paternity included AFLP (amplified fragment length polymorphisms), RAPD (randomly amplified polymorphic DNA) and RAMP (randomly amplified microsatellite polymorphisms) analyses and microsatellite markers. Although most genetic techniques produced only monomorphic bands, analyses with AFLPs indicated that multiple paternity did occur in six of eight litters, confirming that multiple mating within a single oestrous period occurs in this species. Results further indicated that mothers care for young other than their own. On the basis of their high testes-to-bodyweight ratio, male-biased sexual size dimorphism and multiple paternity in litters, sperm competition is considered highly likely to occur in this species.
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Boldogköi Z, Sík A, Dénes A, Reichart A, Toldi J, Gerendai I, Kovács KJ, Palkovits M. Novel tracing paradigms--genetically engineered herpesviruses as tools for mapping functional circuits within the CNS: present status and future prospects. Prog Neurobiol 2004; 72:417-45. [PMID: 15177785 DOI: 10.1016/j.pneurobio.2004.03.010] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Accepted: 03/29/2004] [Indexed: 11/17/2022]
Abstract
The mammalian CNS is composed of an extremely complex meshwork of highly ordered interconnections among billions of neurons. To understand the diverse functions of this neuronal network we need to differentiate between functionally related and nonrelated elements. A powerful labeling method for defining intricate neural circuits is based on the utilization of neurotropic herpesviruses, including pseudorabies virus and herpes simplex virus type 1. The recent development of genetically engineered tracing viruses can open the way toward the conception of novel tract-tracing paradigms. These new-generation tracing viruses may facilitate the clarification of problems, which were inaccessible to earlier approaches. This article first presents a concise review of the general aspects of neuroanatomical tracing protocols. Subsequently, it discusses the molecular biology of alpha-herpesviruses, and the genetic manipulation and gene expression techniques that are utilized for the construction of virus-based tracers. Finally, it describes the current utilization of genetically modified herpesviruses for circuit analysis, and the future directions in their potential applications.
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Affiliation(s)
- Zsolt Boldogköi
- Laboratory of Neuromorphology, Department of Anatomy, Faculty of Medicine, Semmelweis University and Hungarian Academy of Sciences, Budapest, Hungary.
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35
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Augustinova H, Hoeller D, Yao F. The dominant-negative herpes simplex virus type 1 (HSV-1) recombinant CJ83193 can serve as an effective vaccine against wild-type HSV-1 infection in mice. J Virol 2004; 78:5756-65. [PMID: 15140973 PMCID: PMC415800 DOI: 10.1128/jvi.78.11.5756-5765.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
By selectively regulating the expression of the trans-dominant-negative mutant polypeptide UL9-C535C, of herpes simplex virus type 1 (HSV-1) origin binding protein UL9 with the tetracycline repressor (tetR)-mediated gene switch, we recently generated a novel replication-defective and anti-HSV-specific HSV-1 recombinant, CJ83193. The UL9-C535C peptides expressed by CJ83193 can function as a potent intracellular therapy against its own replication, as well as the replication of wild-type HSV-1 and HSV-2 in coinfected cells. In this report, we demonstrate that CJ83193 cannot initiate acute productive infection in corneas of infected mice nor can it reactivate from trigeminal ganglia of mice latently infected by CJ83193 in a mouse ocular model. Given that CJ83193 is capable of expressing the viral alpha, beta, and gamma1 genes but little or no gamma2 genes, we tested the vaccine potential of CJ83193 against HSV-1 infection in a mouse ocular model. Our studies showed that immunization with CJ83193 significantly reduced the yields of challenge HSV in the eyes and trigeminal ganglia on days 3, 5, and 7 postchallenge. Like in mice immunized with the wild-type HSV-1 strain KOS, immunization of mice with CJ83193 prevents the development of keratitis and encephalitis induced by corneal challenge with wild-type HSV-1 strain mP. Delayed-type hypersensitivity (DTH) assays demonstrate that CJ83193 can elicit durable cell-mediated immunity at the same level as that of wild-type HSV-1 and is more effective than that induced by d27, an HSV-1 ICP27 deletion mutant. Moreover, mice immunized with CJ83193 developed strong, durable HSV-1-neutralizing antibodies at levels at least twofold higher than those induced by d27. The results presented in this report have shed new light on the development of effective HSV viral vaccines that encode a unique safety mechanism capable of inhibiting the mutant's own replication and that of wild-type virus.
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Affiliation(s)
- Hanka Augustinova
- Department of Surgery, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
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36
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Hagglund R, Roizman B. Role of ICP0 in the strategy of conquest of the host cell by herpes simplex virus 1. J Virol 2004; 78:2169-78. [PMID: 14963113 PMCID: PMC369245 DOI: 10.1128/jvi.78.5.2169-2178.2004] [Citation(s) in RCA: 180] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Ryan Hagglund
- The Marjorie B. Kovler Viral Oncology Laboratories, The University of Chicago, Chicago, Illinois 60637, USA
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37
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Chen SH, Pearson A, Coen DM, Chen SH. Failure of thymidine kinase-negative herpes simplex virus to reactivate from latency following efficient establishment. J Virol 2004; 78:520-3. [PMID: 14671133 PMCID: PMC303395 DOI: 10.1128/jvi.78.1.520-523.2004] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Thymidine kinase-negative mutants of herpes simplex virus did not reactivate from latency in mouse trigeminal ganglia, even when their latent viral loads were comparable to those that permitted reactivation by wild-type virus. Thus, reduced establishment of latency does not suffice to account for the failure to reactivate.
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Affiliation(s)
- Shih-Heng Chen
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan 70101, Republic of China
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38
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Thompson RL, Shieh MT, Sawtell NM. Analysis of herpes simplex virus ICP0 promoter function in sensory neurons during acute infection, establishment of latency, and reactivation in vivo. J Virol 2003; 77:12319-30. [PMID: 14581568 PMCID: PMC254249 DOI: 10.1128/jvi.77.22.12319-12330.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We have begun an analysis of the functional architecture of the ICP0 promoter in neurons in vivo with the ultimate goal of determining how this gene is regulated during reactivation in vivo. Promoter/reporter mutants in which the Escherichia coli beta-galactosidase (beta-Gal) gene was driven by various permutations of the ICP0 promoter were employed to permit the analysis of promoter function without the added complications that would arise due to inappropriate regulation of ICP0 protein levels. A whole-ganglion immunohistochemical staining procedure (N. M. Sawtell, J. Virol. 77:4127-4138, 2003) was used for direct comparisons of the expression of the promoter/reporter gene to expression of the native protein in the same cell. In this way, the expression of the putative wild-type promoter could be validated and results for mutant promoters could be compared to expression of the native gene. We found that a DNA fragment from bp -562 through the methionine start codon of the ICP0 gene contained all sequences required for properly regulated ICP0 expression in diverse cell types (including sensory neurons of the trigeminal ganglia [TG]) in vitro and in vivo, as indicated by colocalization of ICP0 and beta-Gal. Truncation of the ICP0 promoter to bp -145 or -129 resulted in the loss of immediate-early (alpha) kinetics. The truncated promoters expressed high levels of the reporter gene with leaky late (gamma1) kinetics in vitro and in some cell types in vivo. Unexpectedly, the truncated promoters did not express in TG neurons. Thus, TAATGARAT or other sequences upstream of bp -145 in the ICP0 promoter are required for basal expression of ICP0 in neurons but are not required for basal expression in other cells in vivo. There was a >95% concordance between reporter and native protein expression detected with the 562-bp promoter in neurons during the acute stage. However, this was not the case during reactivation from latency in vivo, as nearly twice as many neurons contained detectable beta-Gal as contained detectable ICP0. This same 562-bp promoter/reporter cassette, when placed in the context of a latency-associated transcript (LAT) null mutant, resulted in >95% concordance of expression of beta-Gal and ICP0 during reactivation in vivo. These last results strongly suggest that there is a posttranscriptional constraint on the expression of ICP0 protein during reactivation from latency and that this constraint is mediated by LAT.
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Affiliation(s)
- R L Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0524, USA.
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39
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Wagner EK, Ramirez JJG, Stingley SWN, Aguilar SA, Buehler L, Devi-Rao GB, Ghazal P. Practical approaches to long oligonucleotide-based DNA microarray: lessons from herpesviruses. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2003; 71:445-91. [PMID: 12108450 DOI: 10.1016/s0079-6603(02)71048-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Edward K Wagner
- Department of Molecular Biology and Biochemistry and Center for Virus Research, University of California, Irvine 92717, USA
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40
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Abstract
Primary infection by herpes simplex virus type 1 (HSV-1) can cause clinical symptoms in the peripheral and central nervous system, upper respiratory tract, and gastrointestinal tract. Recurrent ocular shedding leads to corneal scarring that can progress to vision loss. Consequently, HSV-1 is the leading cause of corneal blindness due to an infectious agent. Bovine herpesvirus 1 (BHV-1) has similar biological properties to HSV-1 and is a significant health concern to the cattle industry. Latency of BHV-1 and HSV-1 is established in sensory neurons of trigeminal ganglia, but latency can be interrupted periodically, leading to reactivation from latency and spread of infectious virus. The ability of HSV-1 and BHV-1 to reactivate from latency leads to virus transmission and can lead to recurrent disease in individuals latently infected with HSV-1. During latency, the only abundant HSV-1 RNA expressed is the latency-associated transcript (LAT). In latently infected cattle, the latency-related (LR) RNA is the only abundant transcript that is expressed. LAT and LR RNA are antisense to ICP0 or bICP0, viral genes that are crucial for productive infection, suggesting that LAT and LR RNA interfere with productive infection by inhibiting ICP0 or bICP0 expression. Numerous studies have concluded that LAT expression is important for the latency-reactivation cycle in animal models. The LR gene has recently been demonstrated to be required for the latency-reactivation cycle in cattle. Several recent studies have demonstrated that LAT and the LR gene inhibit apoptosis (programmed cell death) in trigeminal ganglia of infected animals and transiently transfected cells. The antiapoptotic properties of LAT map to the same sequences that are necessary for promoting reactivation from latency. This review summarizes our current knowledge of factors regulating the latency-reactivation cycle of HSV-1 and BHV-1.
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Affiliation(s)
- Clinton Jones
- Department of Veterinary and Biomedical Sciences, The Nebraska Center for Virology, University of Nebraska-Lincoln, Lincoln, Nebraska 68583-0905, USA.
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41
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Chen XP, Mata M, Kelley M, Glorioso JC, Fink DJ. The relationship of herpes simplex virus latency associated transcript expression to genome copy number: a quantitative study using laser capture microdissection. J Neurovirol 2002; 8:204-10. [PMID: 12053275 DOI: 10.1080/13550280290049642] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
To investigate the quantitative relationship of latent herpes simplex virus (HSV) genomes to the expression of latency associated transcripts (LATs) we used a combination of laser capture microdissection (LCM), polymerase chain reaction (PCR), and quantitative real-time PCR to determine the number of HSV genomes in individual neurons of the mouse trigeminal ganglion (TG) during viral latency. Both LAT-positive and LAT-negative neurons detected by in situ hybridization (ISH) and lifted by LCM contained HSV genomes detected by PCR for HSV ICP47. The number of genomes/cell determined by real-time PCR with probes for HSV UL44 following LCM demonstrated a Poisson distribution with a predicted mean count of 178 genomes/LAT-positive neuron, and 68 genomes/LAT-negative neuron. The range was similar between the LAT-positive and LAT-negative neurons, and there was a substantial overlap in the distributions. These results suggest that the expression of LATs in an amount that is detectable by ISH does not depend only on the number of HSV genomes in the cell, and by implication suggests that neuron-specific factors play a role in the regulation of LAT expression during latency.
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Affiliation(s)
- Xiao-Ping Chen
- Department of Neurology, University of Pittsburgh School of Medicine, Pennsylvania, USA
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42
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Abstract
PrP(c) is a glycophosphatidylinositol-linked cell-surface protein expressed principally by neural tissue. The normal function of this protein is unestablished, although a role in either transmembrane signaling, cell-cell adhesion, or copper metabolism has been proposed. In this study we have investigated the effect of the neurotropic virus herpes simplex virus type 1 (HSV-1) in strains of mice which express different levels of PrP(c). Viral gene expression under the control of the HSV-1 early promoter IE110, detected either by in situ hybridization for RNA transcripts or by beta-galactosidase (beta-Gal) activity from an inserted lacZ gene, showed that the magnitude of HSV replication was retarded in PrP-/- mice. This was reflected in the lower level of acute viral titers in tissues from these virus-inoculated mice. However, HSV-inoculated PrP-/- mice contained higher levels of latent virus in both peripheral and central nervous tissue than those seen in mice which express PrP(c). Our observations show that lack of PrP(c) expression favors the establishment of HSV latency whereas HSV replication proceeds more efficiently in neuronal tissue that expresses this protein. The data further suggest that PrP(c) may be involved in a metabolic pathway that culminates in apoptosis of neurons that have been infected by neurotropic viruses.
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43
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Thackray AM, Bujdoso R. PrP(c) expression influences the establishment of herpes simplex virus type 1 latency. J Virol 2002; 76:2498-509. [PMID: 11836428 PMCID: PMC153799 DOI: 10.1128/jvi.76.5.2498-2509.2002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2001] [Accepted: 11/27/2001] [Indexed: 11/20/2022] Open
Abstract
PrP(c) is a glycophosphatidylinositol-linked cell-surface protein expressed principally by neural tissue. The normal function of this protein is unestablished, although a role in either transmembrane signaling, cell-cell adhesion, or copper metabolism has been proposed. In this study we have investigated the effect of the neurotropic virus herpes simplex virus type 1 (HSV-1) in strains of mice which express different levels of PrP(c). Viral gene expression under the control of the HSV-1 early promoter IE110, detected either by in situ hybridization for RNA transcripts or by beta-galactosidase (beta-Gal) activity from an inserted lacZ gene, showed that the magnitude of HSV replication was retarded in PrP-/- mice. This was reflected in the lower level of acute viral titers in tissues from these virus-inoculated mice. However, HSV-inoculated PrP-/- mice contained higher levels of latent virus in both peripheral and central nervous tissue than those seen in mice which express PrP(c). Our observations show that lack of PrP(c) expression favors the establishment of HSV latency whereas HSV replication proceeds more efficiently in neuronal tissue that expresses this protein. The data further suggest that PrP(c) may be involved in a metabolic pathway that culminates in apoptosis of neurons that have been infected by neurotropic viruses.
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Affiliation(s)
- Alana M Thackray
- Centre for Veterinary Science, Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, United Kingdom CB3 OES
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44
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Coen DM. Quantitation of rare DNAs by PCR. CURRENT PROTOCOLS IN MOLECULAR BIOLOGY 2001; Chapter 15:Unit 15.7. [PMID: 18265121 DOI: 10.1002/0471142727.mb1507s56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This unit presents a protocol that uses the polymerase chain reaction (PCR) to quantitate the numbers of a particular DNA sequence, from 1 to 20,000 molecules per sample. In addition, it helps assess the presence of contaminating sequences, which can seriously affect the outcome of the procedure.
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Affiliation(s)
- D M Coen
- Harvard Medical School, Boston, Massachusetts, USA
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45
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Loudon PT, Blakeley DM, Boursnell ME, Day DA, Duncan IA, Lowden RC, McLean CS, Martin G, Miller JC, Shaw ML. Preclinical safety testing of DISC-hGMCSF to support phase I clinical trials in cancer patients. J Gene Med 2001; 3:458-67. [PMID: 11601759 DOI: 10.1002/jgm.206] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND DISC-hGMCSF is a gH-deleted HSV-2 based vector expressing human GM-CSF that is being developed for cancer immunotherapy. To support first clinical use, a range of preclinical safety studies were performed using DISC-hGMCSF in addition to DISC-murine-GMCSF and the backbone vector, TA-HSV. METHODS The toxicity of the DISC vectors was assessed by repeated dose, neurovirulence and neuroinvasiveness studies in mice, and by safety studies in rabbits, guinea pigs and athymic nude mice. Studies were also conducted to determine whether the vector could establish latency in local ganglia in mice following intradermal injection, and whether it could reactivate from the latent state. The vector biodistribution following intravenous administration was also investigated in mice, using PCR to detect vector DNA. RESULTS The DISC vectors were essentially non-toxic in all the systems studied. No adverse reactions were seen in mice receiving four intravenous doses of DISC-mGMCSF and the results from studies of neurovirulence, neuroinvasiveness, local tolerance in rabbit, general safety in mice and guinea pigs and safety in athymic nude mice were consistent with DISC being unable to replicate and cause disease. The vector could establish latency in local ganglia in mice, but at low efficiency, and could not reactivate infectious virions. Following intravenous administration, vector DNA was widely distributed up to Day 28, but by Day 56 had disappeared from gonads and brain and was only found in blood and liver. CONCLUSION The panel of safety studies provided evidence that DISC-hGMCSF will be unable to replicate and cause disease, and has low toxicity in man. These data were presented to the Medicines Control Agency and the Gene Therapy Advisory Committee as part of the regulatory submissions for a clinical trial in melanoma patients. These submissions have been approved, and DISC-hGMCSF has now entered a phase I clinical trial in the UK by direct intratumoural injection.
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46
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Thompson RL, Sawtell NM. Herpes simplex virus type 1 latency-associated transcript gene promotes neuronal survival. J Virol 2001; 75:6660-75. [PMID: 11413333 PMCID: PMC114389 DOI: 10.1128/jvi.75.14.6660-6675.2001] [Citation(s) in RCA: 151] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A complex interaction has evolved between the host's peripheral nervous system (PNS) and herpes simplex virus type 1 (HSV-1). Sensory neurons are permissive for viral replication, yet the virus can also enter a latent state in these cells. The interplay of viral and neuronal signals that regulate the switch between the viral lytic and latent states is not understood. The latency-associated transcript (LAT) regulates the establishment of the latent state and is required for >65% of the latent infections established by HSV-1 (R. L. Thompson and N. M. Sawtell, J. Virol. 71:5432-5440, 1997). To further investigate how LAT functions, a 1.9-kb deletion that includes the entire LAT promoter and 827 bp of the 5' end of the primary LAT mRNA was introduced into strain 17syn+. The wild-type parent, three independently derived deletion mutants, and two independently derived genomically rescued variants of the mutants were analyzed in a mouse ocular model. The number of latent sites established in trigeminal ganglion (TG) neurons was determined using a single-cell quantitative PCR assay for the viral genome on purified TG neurons. It was found that the LAT null mutants established ~75% fewer latent infections than the number established by the parental strain or rescued variant. The reduced establishment phenotype of LAT null mutants was due at least in part to a dramatic increase in the loss of TG neurons in animals infected with the LAT mutants. Over half of the neurons in the TG were destroyed following infection with the LAT mutants, and this was significantly more than were lost following infection with wild type. This is the first demonstration that the HSV LAT locus prevents the destruction of sensory neurons. The death of these neurons did not appear to be the result of increased apoptosis as measured by a terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay. Animals latently infected with the LAT null mutants reactivated less frequently in vivo and this was consistent with the reduction in the number of neurons in which latency was established. Thus, one function of the LAT gene is to protect sensory neurons and enhance the establishment of latency in the PNS.
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Affiliation(s)
- R L Thompson
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati Medical Center, 231 Albert Sabin Way, Cincinnati, Ohio 45267-0524, USA.
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Wachsman M, Kulka M, Smith CC, Aurelian L. A growth and latency compromised herpes simplex virus type 2 mutant (ICP10DeltaPK) has prophylactic and therapeutic protective activity in guinea pigs. Vaccine 2001; 19:1879-90. [PMID: 11228357 DOI: 10.1016/s0264-410x(00)00446-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A growth compromised herpes simplex virus type 2 (HSV-2) mutant which is deleted in the PK domain of the large subunit of ribonucleotide reductase (ICP10DeltaPK) protects from fatal HSV-2 challenge in the mouse model (Aurelian L, Kokuba H, Smith CC. Vaccine potential of a Herpes Simplex Virus type 2 mutant deleted in the PK domain of the large subunit of ribonucleotide reductase (ICP10). Vaccine 1999;17:1951-1963). Here we report the results of our studies with ICP10DeltaPK in the guinea pig model of recurrent HSV-2 disease. ICP10DeltaPK was also compromised for growth and disease causation in this model. It was not isolated from latently infected ganglia by explant co-cultivation. The proportions of latently infected ganglia were significantly lower for ICP10DeltaPK than HSV-2 [3/25 (12%) and 7/10 (70%), respectively]. Similar results were obtained for the levels of viral DNA (8 x 10(3) and 2 x 10(5) molecules/ganglion for ICP10DeltaPK and HSV-2, respectively]. ICP10DeltaPK immunization caused a significant (P< or = 0.001) decrease in the proportion of animals with primary [1/14 (6%) and 16/16 (100%) for ICP10DeltaPK and PBS, respectively) and recurrent [1/14 (6%) and 11/14 (79%) for ICP10DeltaPK and PBS, respectively) HSV-2 skin lesions. It also protected from genital HSV-2 disease [1/10 and 10/10 for ICP10DeltaPK and PBS, respectively] and decreased the severity of the lesions in both models. Quantitative PCR (Q-PCR) with primers that distinguish between HSV-2 and ICP10DeltaPK indicated that immunization reduced the proportion of ganglia positive for HSV-2 DNA [8/25 (32%) and 7/10 (70%) for ICP10DeltaPK and PBS, respectively) and its levels [3 x 10(3) and 2 x 10(5) molecules/ganglion for ICP10DeltaPK and PBS, respectively]. The proportion of HSV-2 infected animals with recurrent disease was also significantly (P < or = 0.001) decreased by immunization with ICP10DeltaPK [1/15 (7%) and 11/14 (79%) with recurrent disease for ICP10DeltaPK and PBS, respectively], suggesting that ICP10DeltaPK has prophylactic and therapeutic activity in the guinea pig.
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Morrison LA, Zhu L, Thebeau LG. Vaccine-induced serum immunoglobin contributes to protection from herpes simplex virus type 2 genital infection in the presence of immune T cells. J Virol 2001; 75:1195-204. [PMID: 11152492 PMCID: PMC114025 DOI: 10.1128/jvi.75.3.1195-1204.2001] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Herpes simplex type virus 2 (HSV-2) is a sexually transmitted pathogen that causes genital lesions and spreads to the nervous system to establish acute and latent infections. Systemic but not mucosal cellular and humoral immune responses are elicited by immunization of mice with a replication-defective mutant of HSV-2, yet the mice are protected against disease caused by subsequent challenge of the genital mucosa with virulent HSV-2. In this study, we investigated the role of immune serum antibody generated by immunization with a replication-defective HSV-2 vaccine prototype strain in protection of the genital mucosa and the nervous system from HSV-2 infection. Passive transfer of replication-defective virus-immune serum at physiologic concentrations to SCID or B-cell-deficient mice had no effect on replication of challenge virus in the genital mucosa but did significantly reduce the incidence and severity of genital and neurologic disease. In contrast, B-cell-deficient mice immunized with replication-defective HSV-2 were able to control replication of challenge virus in the genital mucosa, but not until 3 days postchallenge, and were not completely protected against genital and neurologic disease. Passive transfer of physiologic amounts of immune serum to immunized, B-cell-deficient mice completely restored their capacity to limit replication of challenge virus in the genital mucosa and prevented signs of genital and systemic disease. In addition, the numbers of viral genomes in the lumbosacral dorsal root ganglia of immunized, B-cell-deficient mice were dramatically reduced by transfer of immune serum prior to challenge. These results suggest that there is an apparent synergism between immune serum antibody and immune T cells in achieving protection and that serum antibody induced by vaccination with replication-defective virus aids in reducing establishment of latent infection after genital infection with HSV-2.
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Affiliation(s)
- L A Morrison
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA.
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Jones CA, Taylor TJ, Knipe DM. Biological properties of herpes simplex virus 2 replication-defective mutant strains in a murine nasal infection model. Virology 2000; 278:137-50. [PMID: 11112490 DOI: 10.1006/viro.2000.0628] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used a mouse nasal model of herpes simplex virus 2 (HSV-2) infection to examine the biological properties of HSV-2 wild-type (wt), TK-negative, and replication-defective strains in vivo. Nasal septa tissue is the major site of wt viral replication post intranasal (i.n.) inoculation. The HSV-2 strain 186 syn(+)-1 wt virus caused lethal encephalitis at doses of 10(4) PFU and above per nostril, and at lower doses no neurons in the trigeminal ganglia were positive for the latency-associated transcript, indicating a lack of latent infection. The 186DeltaKpn TK-negative mutant virus replicated in nasal septa tissue but showed low-level replication in trigeminal ganglia at only one timepoint. In situ hybridization of trigeminal ganglia showed that the number of LAT-positive neurons was proportional to the inoculum dose from 10(3) to 10(6) PFU per nare. The replication-defective mutant virus 5BlacZ showed no replication in nasal septa tissue and no persistence of viral DNA at the inoculation site or the trigeminal ganglia. Nevertheless, inoculation of 5BlacZ or the double-mutant dl5-29 at distal sites reduced acute replication and latent infection of 186DeltaKpn following intranasal challenge. This infection model provides a biological system to test the properties of HSV-2 strains and shows that replication-defective mutant strains do not persist at sites of inoculation or in sensory ganglia but can induce immune protection that reduces the latent viral load of a challenge virus.
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Affiliation(s)
- C A Jones
- Department of Microbiology and Molecular Genetics, Children's Hospital, Boston, Massachusetts 02115, USA
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Geiss BJ, Smith TJ, Leib DA, Morrison LA. Disruption of virion host shutoff activity improves the immunogenicity and protective capacity of a replication-incompetent herpes simplex virus type 1 vaccine strain. J Virol 2000; 74:11137-44. [PMID: 11070010 PMCID: PMC113198 DOI: 10.1128/jvi.74.23.11137-11144.2000] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The virion host shutoff (vhs) protein encoded by herpes simplex virus type 1 (HSV-1) destabilizes both viral and host mRNAs. An HSV-1 strain with a mutation in vhs is attenuated in virulence and induces immune responses in mice that are protective against corneal infection with virulent HSV-1, but it has the capacity to establish latency. Similarly, a replication-incompetent HSV-1 strain with a mutation in ICP8 elicits an immune response protective against corneal challenge, but it may be limited in viral antigen production. We hypothesized therefore that inactivation of vhs in an ICP8(-) virus would yield a replication-incompetent mutant with enhanced immunogenicity and protective capacity. In this study, a vhs(-)/ICP8(-) HSV-1 mutant was engineered. BALB/c mice were immunized with incremental doses of the vhs(-)/ICP8(-) double mutant or vhs(-) or ICP8(-) single mutants, or the mice were mock immunized, and protective immunity against corneal challenge with virulent HSV-1 was assessed. Mice immunized with the vhs(-)/ICP8(-) mutant showed prechallenge serum immunoglobulin G titers comparable to those immunized with replication-competent vhs(-) virus and exceed those of mice immunized with the ICP8(-) single mutant. Following corneal challenge, the degrees of protection against ocular disease, weight loss, encephalitis, and establishment of latency were similar for vhs(-)/ICP8(-) and vhs(-) virus-vaccinated mice. Moreover, the double deleted vhs(-)/ICP8(-) virus protected mice better in all respects than the single deleted ICP8(-) mutant virus. The data indicate that inactivation of vhs in a replication-incompetent virus significantly enhances its protective efficacy while retaining its safety for potential human vaccination. Possible mechanisms of enhanced immunogenicity are discussed.
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Affiliation(s)
- B J Geiss
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, USA
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