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Yang S, Cao D, Jaijyan DK, Wang M, Liu J, Cruz-Cosme R, Wu S, Huang J, Zeng M, Liu X, Sun W, Xiong D, Tang Q, Xiao L, Zhu H. Identification and characterization of Varicella Zoster Virus circular RNA in lytic infection. Nat Commun 2024; 15:4932. [PMID: 38858365 PMCID: PMC11164961 DOI: 10.1038/s41467-024-49112-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 05/17/2024] [Indexed: 06/12/2024] Open
Abstract
This study investigates the role of circular RNAs (circRNAs) in the context of Varicella-Zoster Virus (VZV) lytic infection. We employ two sequencing technologies, short-read sequencing and long-read sequencing, following RNase R treatment on VZV-infected neuroblastoma cells to identify and characterize both cellular and viral circRNAs. Our large scanning analysis identifies and subsequent experiments confirm 200 VZV circRNAs. Moreover, we discover numerous VZV latency-associated transcripts (VLTs)-like circRNAs (circVLTslytic), which contain multiple exons and different isoforms within the same back-splicing breakpoint. To understand the functional significance of these circVLTslytic, we utilize the Bacteria Artificial Chromosome system to disrupt the expression of viral circRNAs in genomic DNA location. We reveal that the sequence flanking circVLTs' 5' splice donor plays a pivotal role as a cis-acting element in the formation of circVLTslytic. The circVLTslytic is dispensable for VZV replication, but the mutation downstream of circVLTslytic exon 5 leads to increased acyclovir sensitivity in VZV infection models. This suggests that circVLTslytic may have a role in modulating the sensitivity to antiviral treatment. The findings shed new insight into the regulation of cellular and viral transcription during VZV lytic infection, emphasizing the intricate interplay between circRNAs and viral processes.
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Affiliation(s)
- Shaomin Yang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen, 518060, China
| | - Di Cao
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Dabbu Kumar Jaijyan
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 070101, USA
| | - Mei Wang
- Institute of Medical Microbiology, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Jian Liu
- School of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou, 363000, China
| | - Ruth Cruz-Cosme
- Department of Microbiology, Howard University College of Medicine, 520 W Street NW, Washington, DC, 20059, USA
| | - Songbin Wu
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Jiabin Huang
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Mulan Zeng
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 070101, USA
| | - Xiaolian Liu
- Institute of Medical Microbiology, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Wuping Sun
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Donglin Xiong
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China
| | - Qiyi Tang
- Department of Microbiology, Howard University College of Medicine, 520 W Street NW, Washington, DC, 20059, USA.
| | - Lizu Xiao
- Department of Pain Medicine and Shenzhen Municipal Key Laboratory for Pain Medicine, Huazhong University of Science and Technology Union Shenzhen Hospital, Shenzhen, China.
| | - Hua Zhu
- Department of Microbiology and Molecular Genetics, New Jersey Medical School, Rutgers University, 225 Warren Street, Newark, NJ, 070101, USA.
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Arvin AM. Creating the "Dew Drop on a Rose Petal": the Molecular Pathogenesis of Varicella-Zoster Virus Skin Lesions. Microbiol Mol Biol Rev 2023; 87:e0011622. [PMID: 37354037 PMCID: PMC10521358 DOI: 10.1128/mmbr.00116-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2023] Open
Abstract
Varicella-zoster virus (VZV) is a human alphaherpesvirus that causes varicella (chicken pox) as the primary infection in a susceptible host. Varicella is very contagious through its transmission by direct contact with vesicular skin lesions that contain high titers of infectious virus and respiratory droplets. While the clinical manifestations of primary VZV infection are well recognized, defining the molecular mechanisms that drive VZV pathogenesis in the naive host before adaptive antiviral immunity is induced has been a challenge due to species specificity. This review focuses on advances made in identifying the differentiated human host cells targeted by VZV to cause varicella, the processes involved in viral takeover of these heterogenous cell types, and the host cell countermeasures that typically culminate in a benign illness. This work has revealed many unexpected and multifaceted mechanisms used by VZV to achieve its high prevalence and persistence in the human population.
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Affiliation(s)
- Ann M. Arvin
- Stanford University School of Medicine, Stanford, California, USA
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3
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Gorbea C, Elhakiem A, Cazalla D. Shaping the host cell environment with viral noncoding RNAs. Semin Cell Dev Biol 2023; 146:20-30. [PMID: 36581481 PMCID: PMC10101873 DOI: 10.1016/j.semcdb.2022.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 12/24/2022] [Accepted: 12/24/2022] [Indexed: 12/29/2022]
Abstract
Just like the cells they infect viruses express different classes of noncoding RNAs (ncRNAs). Viral ncRNAs come in all shapes and forms, and they usually associate with cellular proteins that are important for their functions. Viral ncRNAs have diverse functions, but they all contribute to the viral control of the cellular environment. Viruses utilize ncRNAs to regulate viral replication, to decide whether they should remain latent or reactivate, to evade the host immune responses, or to promote cellular transformation. In this review we describe the diverse functions played by different classes of ncRNAs expressed by adenoviruses and herpesviruses, how they contribute to the viral infection, and how their study led to insights into RNA-based mechanisms at play in host cells.
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Affiliation(s)
- Carlos Gorbea
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Abdalla Elhakiem
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Demián Cazalla
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
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4
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Chung WC, Ravichandran S, Park D, Lee GM, Kim YE, Choi Y, Song MJ, Kim KK, Ahn JH. G-quadruplexes formed by Varicella-Zoster virus reiteration sequences suppress expression of glycoprotein C and regulate viral cell-to-cell spread. PLoS Pathog 2023; 19:e1011095. [PMID: 36630443 PMCID: PMC9873165 DOI: 10.1371/journal.ppat.1011095] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 01/24/2023] [Accepted: 01/02/2023] [Indexed: 01/12/2023] Open
Abstract
G-quadruplex (G4) formed by repetitive guanosine-rich sequences plays important roles in diverse cellular processes; however, its roles in viral infection are not fully understood. In this study, we investigated the genome-wide distribution of G4-forming sequences (G4 motifs) in Varicella-Zoster virus (VZV) and found that G4 motifs are enriched in the internal repeat short and the terminal repeat short regions flanking the unique short region and also in some reiteration (R) sequence regions. A high density of G4 motifs in the R2 region was found on the template strand of ORF14, which encodes glycoprotein C (gC), a virulent factor for viral growth in skin. Analyses such as circular dichroism spectroscopy, thermal difference spectra, and native polyacrylamide gel electrophoresis with oligodeoxynucleotides demonstrated that several G4 motifs in ORF14 form stable G4 structures. In transfection assays, gC expression from the G4-disrupted ORF14 gene was increased at the transcriptional level and became more resistant to suppression by G4-ligand treatment. The recombinant virus containing the G4-disrupted ORF14 gene expressed a higher level of gC mRNA, while it showed a slightly reduced growth. This G4-disrupted ORF14 virus produced smaller plaques than the wild-type virus. Our results demonstrate that G4 formation via reiteration sequences suppresses gC expression during VZV infection and regulates viral cell-to-cell spread.
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Affiliation(s)
- Woo-Chang Chung
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Subramaniyam Ravichandran
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Daegyu Park
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Gwang Myeong Lee
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Young-Eui Kim
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Youngju Choi
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Moon Jung Song
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
- Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
| | - Jin-Hyun Ahn
- Department of Microbiology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
- Biomedical Research Institute, Samsung Medical Center, Seoul, Republic of Korea
- * E-mail:
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5
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Jankeel A, Coimbra-Ibraim I, Messaoudi I. Simian Varicella Virus: Molecular Virology and Mechanisms of Pathogenesis. Curr Top Microbiol Immunol 2023; 438:163-188. [PMID: 34669041 PMCID: PMC9577235 DOI: 10.1007/82_2021_241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Simian varicella virus (SVV) was first isolated in 1966 from African green monkeys (Cercopithecus aethiops) imported from Nairobi, Kenya, to the Liverpool School of Tropical Medicine in the United Kingdom (UK) (Clarkson et al., Arch Gesamte Virusforsch 22:219-234, 1967). SVV infection caused severe disease that resulted in a 56% case fatality rate (CFR) in the imported animals within 48 h of the appearance of a varicella-like rash (Clarkson et al., Arch Gesamte Virusforsch 22:219-234, 1967; Hemme et al., Am J Trop Med Hyg 94:1095-1099, 2016). The deceased animals presented with fever, widespread vesicular rash, and multiple hemorrhagic foci throughout the lungs, liver, and spleen (Clarkson et al., Arch Gesamte Virusforsch 22:219-234, 1967). This outbreak was quickly followed by a second outbreak in 47 patas monkeys (Erythrocebus patas) imported from Chad and Nigeria by Glaxo Laboratories (London, England, UK), which quickly spread within the facility (McCarthy et al., Lancet 2:856-857, 1968).
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Affiliation(s)
- Allen Jankeel
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, USA
| | - Izabela Coimbra-Ibraim
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, USA
| | - Ilhem Messaoudi
- Department of Molecular Biology and Biochemistry, School of Biological Sciences, University of California Irvine, Irvine, CA, USA,Institute for Immunology, University of California Irvine, Irvine, CA, USA,Center for Virus Research, University of California Irvine, Irvine, CA, USA,To whom correspondence should be addressed: Ilhem Messaoudi, PhD, Molecular Biology and Biochemistry, University of California Irvine, 2400 Biological Sciences III, Irvine, CA 92697, Phone: 949-824-3078,
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6
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Arvin AM. Insights From Studies of the Genetics, Pathogenesis, and Immunogenicity of the Varicella Vaccine. J Infect Dis 2022; 226:S385-S391. [PMID: 36265853 DOI: 10.1093/infdis/jiac278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
While the varicella vaccine was created with approaches established for other live attenuated viral vaccines, novel methods to probe virus-host interactions have been used to explore the genetics, pathogenesis, and immunogenicity of the vaccine compared to wild-type varicella-zoster virus (VZV). As summarized here, a mechanism-based understanding of the safety and efficacy of the varicella vaccine has been achieved through these investigations.
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Affiliation(s)
- Ann M Arvin
- Departments of Pediatrics and Microbiology and Immunology, Stanford University School of Medicine, Stanford, California, USA
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7
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Depledge DP, Breuer J. Varicella-Zoster Virus-Genetics, Molecular Evolution and Recombination. Curr Top Microbiol Immunol 2021; 438:1-23. [PMID: 34374828 DOI: 10.1007/82_2021_238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This chapter first details the structure, organization and coding content of the VZV genome to provide a foundation on which the molecular evolution of the virus can be projected. We subsequently describe the evolution of molecular profiling approaches from restriction fragment length polymorphisms to single nucleotide polymorphism profiling to modern day high-throughput sequencing approaches. We describe how the application of these methodologies led to our current model of VZV phylogeograpy including the number and structure of geographic clades and the role of recombination in reshaping these.
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Affiliation(s)
- Daniel P Depledge
- Institute of Virology, Hannover Medical School (MHH), Hannover, Germany. .,Department of Microbiology, NYU School of Medicine, New York, USA.
| | - Judith Breuer
- Department of Infection & Immunology, University College London, London, UK
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8
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Braspenning SE, Sadaoka T, Breuer J, Verjans GMGM, Ouwendijk WJD, Depledge DP. Decoding the Architecture of the Varicella-Zoster Virus Transcriptome. mBio 2020; 11:e01568-20. [PMID: 33024035 PMCID: PMC7542360 DOI: 10.1128/mbio.01568-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/31/2020] [Indexed: 12/14/2022] Open
Abstract
Varicella-zoster virus (VZV), a double-stranded DNA virus, causes varicella, establishes lifelong latency in ganglionic neurons, and reactivates later in life to cause herpes zoster, commonly associated with chronic pain. The VZV genome is densely packed and produces multitudes of overlapping transcripts deriving from both strands. While 71 distinct open reading frames (ORFs) have thus far been experimentally defined, the full coding potential of VZV remains unknown. Here, we integrated multiple short-read RNA sequencing approaches with long-read direct RNA sequencing on RNA isolated from VZV-infected cells to provide a comprehensive reannotation of the lytic VZV transcriptome architecture. Through precise mapping of transcription start sites, splice junctions, and polyadenylation sites, we identified 136 distinct polyadenylated VZV RNAs that encode canonical ORFs, noncanonical ORFs, and ORF fusions, as well as putative noncoding RNAs (ncRNAs). Furthermore, we determined the kinetic class of all VZV transcripts and observed, unexpectedly, that transcripts encoding the ORF62 protein, previously designated Immediate-Early, were expressed with Late kinetics. Our work showcases the complexity of the VZV transcriptome and provides a comprehensive resource that will facilitate future functional studies of coding RNAs, ncRNAs, and the biological mechanisms underlying the regulation of viral transcription and translation during lytic VZV infection.IMPORTANCE Transcription from herpesviral genomes, executed by the host RNA polymerase II and regulated by viral proteins, results in coordinated viral gene expression to efficiently produce infectious progeny. However, the complete coding potential and regulation of viral gene expression remain ill-defined for the human alphaherpesvirus varicella-zoster virus (VZV), causative agent of both varicella and herpes zoster. Here, we present a comprehensive overview of the VZV transcriptome and the kinetic class of all identified viral transcripts, using two virus strains and two biologically relevant cell types. Additionally, our data provide an overview of how VZV diversifies its transcription from one of the smallest herpesviral genomes. Unexpectedly, the transcript encoding the major viral transactivator protein (pORF62) was expressed with Late kinetics, whereas orthologous transcripts in other alphaherpesviruses are typically expressed during the immediate early phase. Therefore, our work both establishes the architecture of the VZV transcriptome and provides insight into regulation of alphaherpesvirus gene expression.
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Affiliation(s)
| | - Tomohiko Sadaoka
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Judith Breuer
- Department of Infection and Immunity, University College London, London, United Kingdom
| | | | | | - Daniel P Depledge
- Department of Medicine, New York University School of Medicine, New York, New York, USA
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9
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Depledge DP, Sadaoka T, Ouwendijk WJD. Molecular Aspects of Varicella-Zoster Virus Latency. Viruses 2018; 10:v10070349. [PMID: 29958408 PMCID: PMC6070824 DOI: 10.3390/v10070349] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/19/2018] [Accepted: 06/27/2018] [Indexed: 02/07/2023] Open
Abstract
Primary varicella-zoster virus (VZV) infection causes varicella (chickenpox) and the establishment of a lifelong latent infection in ganglionic neurons. VZV reactivates in about one-third of infected individuals to cause herpes zoster, often accompanied by neurological complications. The restricted host range of VZV and, until recently, a lack of suitable in vitro models have seriously hampered molecular studies of VZV latency. Nevertheless, recent technological advances facilitated a series of exciting studies that resulted in the discovery of a VZV latency-associated transcript (VLT) and provide novel insights into our understanding of VZV latency and factors that may initiate reactivation. Deducing the function(s) of VLT and the molecular mechanisms involved should now be considered a priority to improve our understanding of factors that govern VZV latency and reactivation. In this review, we summarize the implications of recent discoveries in the VZV latency field from both a virus and host perspective and provide a roadmap for future studies.
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Affiliation(s)
- Daniel P Depledge
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
| | - Tomohiko Sadaoka
- Division of Clinical Virology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
| | - Werner J D Ouwendijk
- Department of Viroscience, Erasmus Medical Centre, 3015 CN Rotterdam, The Netherlands.
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10
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A spliced latency-associated VZV transcript maps antisense to the viral transactivator gene 61. Nat Commun 2018; 9:1167. [PMID: 29563516 PMCID: PMC5862956 DOI: 10.1038/s41467-018-03569-2] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/23/2018] [Indexed: 01/16/2023] Open
Abstract
Varicella-zoster virus (VZV), an alphaherpesvirus, establishes lifelong latent infection in the neurons of >90% humans worldwide, reactivating in one-third to cause shingles, debilitating pain and stroke. How VZV maintains latency remains unclear. Here, using ultra-deep virus-enriched RNA sequencing of latently infected human trigeminal ganglia (TG), we demonstrate the consistent expression of a spliced VZV mRNA, antisense to VZV open reading frame 61 (ORF61). The spliced VZV latency-associated transcript (VLT) is expressed in human TG neurons and encodes a protein with late kinetics in productively infected cells in vitro and in shingles skin lesions. Whereas multiple alternatively spliced VLT isoforms (VLTly) are expressed during lytic infection, a single unique VLT isoform, which specifically suppresses ORF61 gene expression in co-transfected cells, predominates in latently VZV-infected human TG. The discovery of VLT links VZV with the other better characterized human and animal neurotropic alphaherpesviruses and provides insights into VZV latency. Varicella-zoster virus (VZV) establishes lifelong infection in the majority of the population, but mechanisms underlying latency remain unclear. Here, the authors use ultra-deep RNA sequencing, enriched for viral RNAs, of latently infected human trigeminal ganglia and identify a spliced, latency-associated VZV mRNA.
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Dysregulated Glycoprotein B-Mediated Cell-Cell Fusion Disrupts Varicella-Zoster Virus and Host Gene Transcription during Infection. J Virol 2016; 91:JVI.01613-16. [PMID: 27795423 DOI: 10.1128/jvi.01613-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/14/2016] [Indexed: 12/19/2022] Open
Abstract
The highly conserved herpesvirus glycoprotein complex gB/gH-gL mediates membrane fusion during virion entry and cell-cell fusion. Varicella-zoster virus (VZV) characteristically forms multinucleated cells, or syncytia, during the infection of human tissues, but little is known about this process. The cytoplasmic domain of VZV gB (gBcyt) has been implicated in cell-cell fusion regulation because a gB[Y881F] substitution causes hyperfusion. gBcyt regulation is necessary for VZV pathogenesis, as the hyperfusogenic mutant gB[Y881F] is severely attenuated in human skin xenografts. In this study, gBcyt-regulated fusion was investigated by comparing melanoma cells infected with wild-type-like VZV or hyperfusogenic mutants. The gB[Y881F] mutant exhibited dramatically accelerated syncytium formation in melanoma cells caused by fusion of infected cells with many uninfected cells, increased cytoskeleton reorganization, and rapid displacement of nuclei to dense central structures compared to pOka using live-cell confocal microscopy. VZV and human transcriptomes were concurrently investigated using whole transcriptome sequencing (RNA-seq) to identify viral and cellular responses induced when gBcyt regulation was disrupted by the gB[Y881F] substitution. The expression of four vital VZV genes, ORF61 and the genes for glycoproteins gC, gE, and gI, was significantly reduced at 36 h postinfection for the hyperfusogenic mutants. Importantly, hierarchical clustering demonstrated an association of differential gene expression with dysregulated gBcyt-mediated fusion. A subset of Ras GTPase genes linked to membrane remodeling were upregulated in cells infected with the hyperfusogenic mutants. These data implicate gBcyt in the regulation of gB fusion function that, if unmodulated, triggers cellular processes leading to hyperfusion that attenuates VZV infection. IMPORTANCE The highly infectious, human-restricted pathogen varicella-zoster virus (VZV) causes chickenpox and shingles. Postherpetic neuralgia (PHN) is a common complication of shingles that manifests as prolonged excruciating pain, which has proven difficult to treat. The formation of fused multinucleated cells in ganglia might be associated with this condition. An effective vaccine against VZV is available but not recommended for immunocompromised individuals, highlighting the need for new therapies. This study investigated the viral and cellular responses to hyperfusion, a condition where the usual constraints of cell membranes are overcome and cells form multinucleated cells. This process hinders VZV and is regulated by a viral glycoprotein, gB. A combination of live-cell imaging and next-generation genomics revealed an alteration in viral and cellular responses during hyperfusion that was caused by the loss of gB regulation. These studies reveal mechanisms central to VZV pathogenesis, potentially leading to improved therapies.
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Khalil MI, Ruyechan WT, Hay J, Arvin A. Differential effects of Sp cellular transcription factors on viral promoter activation by varicella-zoster virus (VZV) IE62 protein. Virology 2015; 485:47-57. [PMID: 26207799 PMCID: PMC4619144 DOI: 10.1016/j.virol.2015.06.031] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/08/2015] [Accepted: 06/25/2015] [Indexed: 12/12/2022]
Abstract
The immediate early (IE) 62 protein is the major varicella-zoster virus (VZV) regulatory factor. Analysis of the VZV genome revealed 40 predicted GC-rich boxes within 36 promoters. We examined effects of ectopic expression of Sp1-Sp4 on IE62- mediated transactivation of three viral promoters. Ectopic expression of Sp3 and Sp4 enhanced IE62 activation of ORF3 and gI promoters while Sp3 reduced IE62 activation of ORF28/29 promoter and VZV DNA replication. Sp2 reduced IE62 transactivation of gI while Sp1 had no significant influence on IE62 activation with any of these viral promoters. Electrophoretic mobility shift assays (EMSA) confirmed binding of Sp1 and Sp3 but not Sp2 and Sp4 to the gI promoter. Sp1-4 bound to IE62 and amino acids 238-258 of IE62 were important for the interaction with Sp3 and Sp4 as well as Sp1. This work shows that Sp family members have differential effects on IE62-mediated transactivation in a promoter-dependent manner.
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Affiliation(s)
- Mohamed I Khalil
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, United States; Department of Molecular Biology, National Research Center EL-Buhouth St., Dokki, Cairo, Egypt.
| | - William T Ruyechan
- Department of Microbiology and Immunology and the Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY, United States
| | - John Hay
- Department of Microbiology and Immunology and the Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY, United States
| | - Ann Arvin
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA, United States
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The ORF61 Protein Encoded by Simian Varicella Virus and Varicella-Zoster Virus Inhibits NF-κB Signaling by Interfering with IκBα Degradation. J Virol 2015; 89:8687-700. [PMID: 26085158 DOI: 10.1128/jvi.01149-15] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 06/12/2015] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Varicella-zoster virus (VZV) causes chickenpox upon primary infection and establishes latency in ganglia. Reactivation from latency causes herpes zoster, which may be complicated by postherpetic neuralgia. Innate immunity mediated by interferon and proinflammatory cytokines represents the first line of immune defense upon infection and reactivation. VZV is known to interfere with multiple innate immune signaling pathways, including the central transcription factor NF-κB. However, the role of these inhibitory mechanisms in vivo is unknown. Simian varicella virus (SVV) infection of rhesus macaques recapitulates key aspects of VZV pathogenesis, and this model thus permits examination of the role of immune evasion mechanisms in vivo. Here, we compare SVV and VZV with respect to interference with NF-κB activation. We demonstrate that both viruses prevent ubiquitination of the NF-κB inhibitor IκBα, whereas SVV additionally prevents IκBα phosphorylation. We show that the ORF61 proteins of VZV and SVV are sufficient to prevent IκBα ubiquitination upon ectopic expression. We further demonstrate that SVV ORF61 interacts with β-TrCP, a subunit of the SCF ubiquitin ligase complex that mediates the degradation of IκBα. This interaction seems to inactivate SCF-mediated protein degradation in general, since the unrelated β-TrCP target Snail is also stabilized by ORF61. In addition to ORF61, SVV seems to encode additional inhibitors of the NF-κB pathway, since SVV with ORF61 deleted still prevented IκBα phosphorylation and degradation. Taken together, our data demonstrate that SVV interferes with tumor necrosis factor alpha (TNF-α)-induced NF-κB activation at multiple levels, which is consistent with the importance of these countermechanisms for varicella virus infection. IMPORTANCE The role of innate immunity during the establishment of primary infection, latency, and reactivation by varicella-zoster virus (VZV) is incompletely understood. Since infection of rhesus macaques by simian varicella virus (SVV) is used as an animal model of VZV infection, we characterized the molecular mechanism by which SVV interferes with innate immune activation. Specifically, we studied how SVV prevents activation of the transcription factor NF-κB, a central factor in eliciting proinflammatory responses. The identification of molecular mechanisms that counteract innate immunity might ultimately lead to better vaccines and treatments for VZV, since overcoming these mechanisms, either by small-molecule inhibition or by genetic modification of vaccine strains, is expected to reduce the pathogenic potential of VZV. Moreover, using SVV infection of rhesus macaques, it will be possible to study how increasing the vulnerability of varicella viruses to innate immunity will impact viral pathogenesis.
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Zerboni L, Sen N, Oliver SL, Arvin AM. Molecular mechanisms of varicella zoster virus pathogenesis. Nat Rev Microbiol 2014; 12:197-210. [PMID: 24509782 PMCID: PMC4066823 DOI: 10.1038/nrmicro3215] [Citation(s) in RCA: 268] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Varicella zoster virus (VZV) is the causative agent of varicella (chickenpox) and zoster (shingles). Investigating VZV pathogenesis is challenging as VZV is a human-specific virus and infection does not occur, or is highly restricted, in other species. However, the use of human tissue xenografts in mice with severe combined immunodeficiency (SCID) enables the analysis of VZV infection in differentiated human cells in their typical tissue microenvironment. Xenografts of human skin, dorsal root ganglia or foetal thymus that contains T cells can be infected with mutant viruses or in the presence of inhibitors of viral or cellular functions to assess the molecular mechanisms of VZV-host interactions. In this Review, we discuss how these models have improved our understanding of VZV pathogenesis.
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Affiliation(s)
- Leigh Zerboni
- Departments of Pediatrics and of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Nandini Sen
- Departments of Pediatrics and of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Stefan L Oliver
- Departments of Pediatrics and of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
| | - Ann M Arvin
- Departments of Pediatrics and of Microbiology & Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
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15
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Khalil MI, Sommer M, Arvin A, Hay J, Ruyechan WT. Cellular transcription factor YY1 mediates the varicella-zoster virus (VZV) IE62 transcriptional activation. Virology 2014; 449:244-53. [PMID: 24418559 DOI: 10.1016/j.virol.2013.11.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 08/19/2013] [Accepted: 11/20/2013] [Indexed: 12/12/2022]
Abstract
Several cellular transcription factors have been shown to be involved in IE62-mediated activation. The YY1 cellular transcription factor has activating and repressive effects on gene transcription. Analysis of the VZV genome revealed 19 postulated YY1 binding sites located within putative promoters of 16 VZV genes. Electrophoretic mobility shift assays (EMSA) confirmed the binding of YY1 to ORF10, ORF28/29 and gI promoters and the mutation of these binding sites inhibited YY1 binding and the promoter activation by IE62 alone or following VZV infection. Mutation of the ORF28/29 YY1 site in the VZV genome displayed insignificant influence on virus growth in melanoma cells; but it inhibited the virus replication significantly at day 5 and 6 post infection in HELF cells. This work suggests a novel role for the cellular factor YY1 in VZV replication through the mediation of IE62 activation of viral gene expression.
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Affiliation(s)
- Mohamed I Khalil
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, United States; Department of Molecular Biology, National Research Center, Dokki, Cairo, Egypt.
| | - Marvin Sommer
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Ann Arvin
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - John Hay
- Department of Microbiology and Immunology and the Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY, United States
| | - William T Ruyechan
- Department of Microbiology and Immunology and the Witebsky Center for Microbial Pathogenesis and Immunology, University at Buffalo, Buffalo, NY, United States
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16
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Khalil MI, Sommer M, Arvin A, Hay J, Ruyechan WT. Regulation of the varicella-zoster virus ORF3 promoter by cellular and viral factors. Virology 2013; 440:171-81. [PMID: 23523134 DOI: 10.1016/j.virol.2013.02.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 02/20/2013] [Accepted: 02/24/2013] [Indexed: 11/18/2022]
Abstract
The varicella zoster virus (VZV) immediate early 62 protein (IE62) activates most if not all identified promoters of VZV genes and also some minimum model promoters that contain only a TATA box element. Analysis of the DNA elements that function in IE62 activation of the VZV ORF3 promoter revealed that the 100 nucleotides before the translation start site of the ORF3 gene contains the promoter elements. This promoter lacks any functional TATA box element. Cellular transcription factors Sp1, Sp3 and YY1 bind to the promoter, and mutation of their binding sites inhibited ORF3 gene expression. VZV regulatory proteins, IE63 and ORF29, ORF61 and ORF10 proteins inhibited IE62-mediated activation of this promoter. Mutation of the Sp1/Sp3 binding site in the VZV genome did not alter VZV replication kinetics. This work suggests that Sp family proteins contribute to the activation of VZV promoters by IE62 in the absence of functional TATA box.
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Affiliation(s)
- Mohamed I Khalil
- Departments of Pediatrics and Microbiology & Immunology, Stanford University School of Medicine, Stanford, CA 94305, United States.
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Identification of a hydrophobic domain in varicella-zoster virus ORF61 necessary for ORF61 self-interaction, viral replication, and skin pathogenesis. J Virol 2013; 87:4075-9. [PMID: 23345513 DOI: 10.1128/jvi.02963-12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The varicella-zoster virus (VZV) ORF61 protein is necessary for normal replication in vitro and virulence in human skin xenografts in the severe combined immunodeficiency mouse model in vivo. These experiments identify a hydrophobic domain that mediates ORF61 self-interaction. While not needed to inhibit host cell defenses, disruption of this domain (residues 250 to 320) severely impairs VZV growth, transactivation of the immediate early 63 and glycoprotein E genes, and the pathogenesis of VZV skin infection in vivo.
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Boutell C, Everett RD. Regulation of alphaherpesvirus infections by the ICP0 family of proteins. J Gen Virol 2012; 94:465-481. [PMID: 23239572 DOI: 10.1099/vir.0.048900-0] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Immediate-early protein ICP0 of herpes simplex virus type 1 (HSV-1) is important for the regulation of lytic and latent viral infection. Like the related proteins expressed by other alphaherpesviruses, ICP0 has a zinc-stabilized RING finger domain that confers E3 ubiquitin ligase activity. This domain is essential for the core functions of ICP0 and its activity leads to the degradation of a number of cellular proteins, some of which are involved in cellular defences that restrict viral infection. The article reviews recent advances in ICP0-related research, with an emphasis on the mechanisms by which ICP0 and related proteins counteract antiviral restriction and the roles in this process of cellular nuclear substructures known as ND10 or PML nuclear bodies. We also summarize recent advances in the understanding of the biochemical aspects of ICP0 activity. These studies highlight the importance of the SUMO conjugation pathway in both intrinsic resistance to HSV-1 infection and in substrate targeting by ICP0. The topics discussed in this review are relevant not only to HSV-1 infection, but also to cellular intrinsic resistance against herpesviruses more generally and the mechanisms by which viruses can evade this restriction.
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Affiliation(s)
- Chris Boutell
- MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, Scotland, UK
| | - Roger D Everett
- MRC-University of Glasgow Centre for Virus Research, 8 Church Street, Glasgow G11 5JR, Scotland, UK
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Attenuation of the adaptive immune response in rhesus macaques infected with simian varicella virus lacking open reading frame 61. J Virol 2012; 87:2151-63. [PMID: 23221560 DOI: 10.1128/jvi.02369-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Varicella zoster virus (VZV) is a neurotropic alphaherpesvirus that causes chickenpox during primary infection and establishes latency in sensory ganglia. Infection of rhesus macaques (RM) with the homologous simian varicella virus (SVV) recapitulates hallmarks of VZV infection. We have shown that an antisense transcript of SVV open reading frame 61 (ORF61), a viral transactivator, was detected most frequently in latently infected RM sensory ganglia. In this study, we compared disease progression, viral replication, immune response, and the establishment of latency following intrabronchial infection with a recombinant SVV lacking ORF61 (SVVΔORF61) to those following infection with wild-type (WT) SVV. Varicella severity and viral latency within sensory ganglia were comparable in RMs infected with SVVΔORF61 and WT SVV. In contrast, viral loads, B and T cell responses, and plasma inflammatory cytokine levels were decreased in RMs infected with SVVΔORF61. To investigate the mechanisms underlying the reduced adaptive immune response, we compared acute SVV gene expression, frequency and proliferation of dendritic cell (DC) subsets, and the expression of innate antiviral genes in bronchoalveolar lavage (BAL) samples. The abundance of SVV transcripts in all kinetic classes was significantly decreased in RMs infected with SVVΔORF61. In addition, we detected a higher frequency and proliferation of plasmacytoid dendritic cells in BAL fluid at 3 days postinfection in RMs infected with SVVΔORF61, which was accompanied by a slight increase in type I interferon gene expression. Taken together, our data suggest that ORF61 plays an important role in orchestrating viral gene expression in vivo and interferes with the host antiviral interferon response.
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Varicella-zoster virus inhibition of the NF-κB pathway during infection of human dendritic cells: role for open reading frame 61 as a modulator of NF-κB activity. J Virol 2011; 86:1193-202. [PMID: 22090112 DOI: 10.1128/jvi.06400-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Dendritic cells (DC) are antigen-presenting cells essential for initiating primary immune responses and therefore an ideal target for viral immune evasion. Varicella-zoster virus (VZV) can productively infect immature human DCs and impair their function as immune effectors by inhibiting their maturation, as evidenced by the expression modulation of functionally important cell surface immune molecules CD80, CD86, CD83, and major histocompatibility complex I. The NF-κB pathway largely regulates the expression of these immune molecules, and therefore we sought to determine whether VZV infection of DCs modulates the NF-κB pathway. Nuclear localization of NF-κB p50 and p65 indicates pathway activation; however, immunofluorescence studies revealed cytoplasmic retention of these NF-κB subunits in VZV-infected DCs. Western blotting revealed phosphorylation of the inhibitor of κBα (IκBα) in VZV-infected DCs, indicating that the pathway is active at this point. We conclude that VZV infection of DC inhibits the NF-κB pathway following protein phosphorylation but before the translocation of NF-κB subunits into the nucleus. An NF-κB reporter assay identified VZV open reading frame 61 (ORF61) as an inhibitor of tumor necrosis factor alpha-induced NF-κB reporter activity. Mutational analysis of ORF61 identified the E3 ubiquitin ligase domain as a region required for NF-κB pathway inhibition. In summary, we provide evidence that VZV inhibits the NF-κB signaling pathway in human DCs and that the E3 ubiquitin ligase domain of ORF61 is required to modulate this pathway. Thus, this work identifies a mechanism by which VZV modulates host immune function.
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Wang L, Oliver SL, Sommer M, Rajamani J, Reichelt M, Arvin AM. Disruption of PML nuclear bodies is mediated by ORF61 SUMO-interacting motifs and required for varicella-zoster virus pathogenesis in skin. PLoS Pathog 2011; 7:e1002157. [PMID: 21901090 PMCID: PMC3161977 DOI: 10.1371/journal.ppat.1002157] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 05/23/2011] [Indexed: 12/15/2022] Open
Abstract
Promyelocytic leukemia protein (PML) has antiviral functions and many viruses encode gene products that disrupt PML nuclear bodies (PML NBs). However, evidence of the relevance of PML NB modification for viral pathogenesis is limited and little is known about viral gene functions required for PML NB disruption in infected cells in vivo. Varicella-zoster virus (VZV) is a human alphaherpesvirus that causes cutaneous lesions during primary and recurrent infection. Here we show that VZV disrupts PML NBs in infected cells in human skin xenografts in SCID mice and that the disruption is achieved by open reading frame 61 (ORF61) protein via its SUMO-interacting motifs (SIMs). Three conserved SIMs mediated ORF61 binding to SUMO1 and were required for ORF61 association with and disruption of PML NBs. Mutation of the ORF61 SIMs in the VZV genome showed that these motifs were necessary for PML NB dispersal in VZV-infected cells in vitro. In vivo, PML NBs were highly abundant, especially in basal layer cells of uninfected skin, whereas their frequency was significantly decreased in VZV-infected cells. In contrast, mutation of the ORF61 SIMs reduced ORF61 association with PML NBs, most PML NBs remained intact and importantly, viral replication in skin was severely impaired. The ORF61 SIM mutant virus failed to cause the typical VZV lesions that penetrate across the basement membrane into the dermis and viral spread in the epidermis was limited. These experiments indicate that VZV pathogenesis in skin depends upon the ORF61-mediated disruption of PML NBs and that the ORF61 SUMO-binding function is necessary for this effect. More broadly, our study elucidates the importance of PML NBs for the innate control of a viral pathogen during infection of differentiated cells within their tissue microenvironment in vivo and the requirement for a viral protein with SUMO-binding capacity to counteract this intrinsic barrier. PML nuclear bodies (PML NBs) are spherical nuclear structures that are present in most human and animal cells. These bodies contribute to anti-viral defense and therefore many viruses have developed strategies to disrupt them. This interaction has been demonstrated for a number of viruses in cultured cells but little is known about these processes in differentiated cells within human tissues. Varicella-zoster virus (VZV) is a human alphaherpesvirus that causes chicken pox and shingle lesions in skin. Here we show that VZV disrupts PML NBs in epidermal and dermal cells in skin tissues implanted subcutaneously in immunodeficient mice. We found that PML NB dispersal is mediated by VZV ORF61 protein and is required for VZV cell to cell spread and lesion formation in skin. The ability of ORF61 to disrupt PML NBs depends on its capacity to bind to SUMO1 protein, which is conjugated to PML and other proteins within PML NBs. To our knowledge, our study provides the first evidence of PML NB modification through the SUMO-binding function of a viral protein, VZV ORF61, and the importance of this molecular mechanism for virus-induced PML NB disruption in differentiated cells infected within their tissue microenvironment in vivo.
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MESH Headings
- Animals
- Cell Differentiation
- Cell Line, Tumor
- Cell Proliferation
- Cloning, Molecular
- Genes, Viral
- Herpesvirus 3, Human/genetics
- Herpesvirus 3, Human/pathogenicity
- Herpesvirus 3, Human/physiology
- Humans
- Intranuclear Inclusion Bodies/metabolism
- Intranuclear Inclusion Bodies/virology
- Leukemia, Promyelocytic, Acute
- Mice
- Mice, SCID
- Models, Animal
- Mutagenesis
- Plasmids/genetics
- Protein Interaction Domains and Motifs/genetics
- SUMO-1 Protein/genetics
- SUMO-1 Protein/metabolism
- Skin/virology
- Up-Regulation
- Viral Proteins/genetics
- Viral Proteins/metabolism
- Virus Replication
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Affiliation(s)
- Li Wang
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, United States of America.
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22
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Che X, Oliver SL, Sommer MH, Rajamani J, Reichelt M, Arvin AM. Identification and functional characterization of the Varicella zoster virus ORF11 gene product. Virology 2011; 412:156-66. [PMID: 21276599 DOI: 10.1016/j.virol.2010.12.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/17/2010] [Accepted: 12/27/2010] [Indexed: 11/18/2022]
Abstract
The deletion of ORF11 severely impaired VZV infection of human skin xenografts. Here, we investigate the characteristics and functions of the ORF11 gene product. ORF11 is expressed as a 118kDa polypeptide in VZV-infected cells; the protein is present in the nucleus and cytoplasm and is incorporated into VZ virions. Although ORF11 had little effect in transactivating VZV gene promoters in transfection assays, deleting ORF11 from the virus was associated with reduced expression of immediate early proteins IE4, IE62 and IE63, and the major glycoprotein, gE. ORF11 was identified as an RNA binding protein and its RNA binding domain was defined. However, disrupting the ORF11 RNA binding domain did not affect skin infection, indicating that RNA binding capacity, conserved among the alphaherpesviruses homologues, is not essential while the contribution of ORF11 to the expression of the IE proteins and gE may be required for VZV pathogenesis in skin in vivo.
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Affiliation(s)
- Xibing Che
- Departments of Pediatrics and Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
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23
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Abstract
Varicella zoster virus (VZV) is the causative agent of chickenpox and shingles. During productive infection the complete VZV proteome consisting of some 68 unique gene products is expressed through interaction of a small number of viral transcriptional activators with the general transcription apparatus of the host cell. Recent work has shown that the major viral transactivator, commonly designated the IE62 protein, interacts with the human Mediator of transcription. This interaction requires direct contact between the MED25 subunit of Mediator and the acidic N-terminal transactivation domain of IE62. A second cellular factor, host cell factor-1, has been shown to be the common element in two mechanisms of activation of the promoter driving expression of the gene encoding IE62. Finally, the ubiquitous cellular transcription factors Sp1, Sp3, and YY1 have been shown to interact with sequences near the VZV origin of DNA replication and in the case of Sp1/Sp3 to influence replication efficiency.
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24
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Folster JM, Jensen NJ, Ruyechan WT, Inoue N, Schmid DS. Regulation of the expression of the varicella-zoster virus open reading frame 66 gene. Virus Res 2010; 155:334-42. [PMID: 21074584 DOI: 10.1016/j.virusres.2010.11.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 11/01/2010] [Accepted: 11/04/2010] [Indexed: 11/18/2022]
Abstract
The varicella-zoster virus (VZV) open reading frame (ORF) 66 encodes a serine/threonine kinase that phosphorylates the major viral transactivator protein, immediate-early (IE) 62, preventing its nuclear importation. Cytoplasmic sequestration of IE62 may alter viral gene transcription and could serve as a mechanism for maintaining VZV latency. We examined the regulation of expression of the ORF66 gene by mapping the promoter region, which was localized to within 150 bases of the start codon. The ORF66 promoter was activated by two viral regulatory proteins, IE62 and IE63. We evaluated the binding of viral regulatory proteins and cellular transcription factors based on recognized cellular transcription factor binding sites identified within the ORF66 promoter. These included Sp1 and TBP binding sites, several of which were essential for optimal promoter activity. Site-directed mutations in Sp1 and TBP binding sites led to varying degrees of impairment of ORF66 gene expression in the context of VZV infection. We also examined the effect of Sp1 and TBP mutations on IE62, Sp1, and TBP binding. These studies reveal that host cell-derived and viral factors contribute to and cooperate in the expression of this important viral kinase gene.
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Affiliation(s)
- Jennifer M Folster
- Division of Viral Diseases, Measles, Mumps, Rubella, and Herpesvirus Laboratory Branch, Centers for Disease Control and Prevention, Office of Infectious Diseases, National Center for Immunizations and Respiratory Diseases, Atlanta, GA 30333, USA.
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Zhang Z, Selariu A, Warden C, Huang G, Huang Y, Zaccheus O, Cheng T, Xia N, Zhu H. Genome-wide mutagenesis reveals that ORF7 is a novel VZV skin-tropic factor. PLoS Pathog 2010; 6:e1000971. [PMID: 20617166 PMCID: PMC2895648 DOI: 10.1371/journal.ppat.1000971] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 05/27/2010] [Indexed: 11/30/2022] Open
Abstract
The Varicella Zoster Virus (VZV) is a ubiquitous human alpha-herpesvirus that is the causative agent of chicken pox and shingles. Although an attenuated VZV vaccine (v-Oka) has been widely used in children in the United States, chicken pox outbreaks are still seen, and the shingles vaccine only reduces the risk of shingles by 50%. Therefore, VZV still remains an important public health concern. Knowledge of VZV replication and pathogenesis remains limited due to its highly cell-associated nature in cultured cells, the difficulty of generating recombinant viruses, and VZV's almost exclusive tropism for human cells and tissues. In order to circumvent these hurdles, we cloned the entire VZV (p-Oka) genome into a bacterial artificial chromosome that included a dual-reporter system (GFP and luciferase reporter genes). We used PCR-based mutagenesis and the homologous recombination system in the E. coli to individually delete each of the genome's 70 unique ORFs. The collection of viral mutants obtained was systematically examined both in MeWo cells and in cultured human fetal skin organ samples. We use our genome-wide deletion library to provide novel functional annotations to 51% of the VZV proteome. We found 44 out of 70 VZV ORFs to be essential for viral replication. Among the 26 non-essential ORF deletion mutants, eight have discernable growth defects in MeWo. Interestingly, four ORFs were found to be required for viral replication in skin organ cultures, but not in MeWo cells, suggesting their potential roles as skin tropism factors. One of the genes (ORF7) has never been described as a skin tropic factor. The global profiling of the VZV genome gives further insights into the replication and pathogenesis of this virus, which can lead to improved prevention and therapy of chicken pox and shingles. The Varicella Zoster Virus (VZV) is the causative agent of chicken pox and shingles. The long-term efficacy of the current chickenpox vaccine is yet to be determined, and the current shingles vaccine fails to provide protective immunity for a substantial number of individuals. Shingles can also lead to post-herpetic neuralgia (PHN), a debilitating condition associated with an intractable pain that can linger for life. Therefore, VZV remains an important public health concern. We use growth-rate analysis of our genome-wide deletion library to determine the essentiality of all known VZV genes, including novel annotations for 51% of the VZV proteome. We also discovered a novel skin-tropic factor encoded by ORF7. Overall, our identification of genes essential for VZV replication and pathogenesis will serve as the basis for multiple in-depth genetic studies of VZV, which can lead to improved prevention and therapy of chicken pox and shingles. For example, essential genes may be appealing drug targets and genes whose deletion causes a substantial growth defect may be prospective candidates for novel live attenuated vaccines.
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Affiliation(s)
- Zhen Zhang
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Anca Selariu
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Charles Warden
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Grace Huang
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Ying Huang
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Oluleke Zaccheus
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
| | - Tong Cheng
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, China
| | - Ningshao Xia
- National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, China
| | - Hua Zhu
- Department of Microbiology and Molecular Genetics, UMNDJ-Newark, Newark, New Jersey, United States of America
- * E-mail:
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26
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Walters MS, Kyratsous CA, Silverstein SJ. The RING finger domain of Varicella-Zoster virus ORF61p has E3 ubiquitin ligase activity that is essential for efficient autoubiquitination and dispersion of Sp100-containing nuclear bodies. J Virol 2010; 84:6861-5. [PMID: 20392849 PMCID: PMC2903287 DOI: 10.1128/jvi.00335-10] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 04/06/2010] [Indexed: 11/20/2022] Open
Abstract
Varicella zoster virus encodes an immediate-early (IE) protein termed ORF61p that is orthologous to the herpes simplex virus IE protein ICP0. Although these proteins share several functional properties, ORF61p does not fully substitute for ICP0. The greatest region of similarity between these proteins is a RING finger domain. We demonstrate that disruption of the ORF61p RING finger domain by amino acid substitution (Cys19Gly) alters ORF61p intranuclear distribution and abolishes ORF61p-mediated dispersion of Sp100-containing nuclear bodies. In addition, we demonstrate that an intact ORF61p RING finger domain is necessary for E3 ubiquitin ligase activity and is required for autoubiquitination and regulation of protein stability.
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Affiliation(s)
- Matthew S. Walters
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, 701 W. 168th St., New York, New York 10032
| | - Christos A. Kyratsous
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, 701 W. 168th St., New York, New York 10032
| | - Saul J. Silverstein
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, 701 W. 168th St., New York, New York 10032
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Everett RD, Boutell C, McNair C, Grant L, Orr A. Comparison of the biological and biochemical activities of several members of the alphaherpesvirus ICP0 family of proteins. J Virol 2010; 84:3476-87. [PMID: 20106921 PMCID: PMC2838103 DOI: 10.1128/jvi.02544-09] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 01/15/2010] [Indexed: 11/20/2022] Open
Abstract
Immediate-early protein ICP0 of herpes simplex virus type 1 (HSV-1) is an E3 ubiquitin ligase of the RING finger class that is required for efficient lytic infection and reactivation from latency. Other alphaherpesviruses also express ICP0-related RING finger proteins, but these have limited homology outside the core RING domain. Existing evidence indicates that ICP0 family members have similar properties, but there has been no systematic comparison of the biochemical activities and biological functions of these proteins. Here, we describe an inducible cell line system that allows expression of the ICP0-related proteins of bovine herpes virus type 1 (BHV-1), equine herpesvirus type 1 (EHV-1), pseudorabies virus (PRV), and varicella-zoster virus (VZV) and their subsequent functional analysis. We report that the RING domains of all the proteins have E3 ubiquitin ligase activity in vitro. The BHV-1, EHV-1, and PRV proteins complement ICP0-null mutant HSV-1 plaque formation and induce derepression of quiescent HSV-1 genomes to levels similar to those achieved by ICP0 itself. VICP0, the ICP0 expressed by VZV, was found to be extremely unstable, which limited its analysis in this system. We compared the abilities of the ICP0-related proteins to disrupt ND10, to induce degradation of PML and Sp100, to affect key components of the interferon signaling pathway, and to interfere with induction of interferon-stimulated genes. We found that the property that correlated most closely with their biological activities was the ability to preclude the recruitment of cellular ND10 proteins to sites closely associated with incoming HSV-1 genomes and early replication compartments.
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Affiliation(s)
- Roger D Everett
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, Scotland, United Kingdom.
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Gershon MD, Gershon AA. VZV infection of keratinocytes: production of cell-free infectious virions in vivo. Curr Top Microbiol Immunol 2010; 342:173-88. [PMID: 20225011 PMCID: PMC5408736 DOI: 10.1007/82_2010_13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Varicella-zoster virus (VZV) is the cause of varicella (chickenpox) and zoster (shingles). Varicella is a primary infection that spreads rapidly in epidemics while zoster is a secondary infection that occurs sporadically as a result of the reactivation of previously acquired VZV. Reactivation is made possible by the establishment of latency during the initial episode of varicella. The signature lesions of both varicella and zoster are cutaneous vesicles, which are filled with a clear fluid that is rich in infectious viral particles. It has been postulated that the skin is the critical organ in which both host-to-host transmission of VZV and the infection of neurons to establish latency occur. This hypothesis is built on evidence that the large cation-independent mannose 6-phosphate receptor (MPR(ci)) interacts with VZV in virtually all infected cells, except those of the suprabasal epidermis, in a way that prevents the release of infectious viral particles. Specifically, the virus is diverted in an MPR(ci)-dependent manner from the secretory pathway to late endosomes where VZV is degraded. Because nonepidermal cells are thus prevented from releasing infectious VZV, a slow process, possibly involving fusion of infected cells with their neighbors, becomes the means by which VZV is disseminated. In the epidermis, however, the maturation of keratinocytes to give rise to corneocytes in the suprabasal epidermis is associated uniquely with a downregulation of the MPR(ci). As a result, the diversion of VZV to late endosomes does not occur in the suprabasal epidermis where vesicular lesions occur. The formation of the waterproof, chemically resistant barrier of the epidermis, however, requires that constitutive secretion outlast the downregulation of the endosomal pathway. Infectious VZV is therefore secreted by default, accounting for the presence of infectious virions in vesicular fluid. Sloughing of corneocytes, aided by scratching, then aerosolizes the virus, which can float with dust to be inhaled by susceptible hosts. Infectious virions also bathe the terminals of those sensory neurons that innervate the epidermis. These terminals become infected with VZV and provide a route, retrograde transport, which can conduct VZV to cranial nerve (CNG), dorsal root ganglia (DRG), and enteric ganglia (EG) to establish latency. Reactivation returns VZV to the skin, now via anterograde transport in axons, to cause the lesions of zoster. Evidence in support of these hypotheses includes observations of the VZV-infected human epidermis and studies of guinea pig neurons in an in vitro model system.
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Affiliation(s)
- Michael D Gershon
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
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Histone deacetylases 1 and 2 are phosphorylated at novel sites during varicella-zoster virus infection. J Virol 2009; 83:11502-13. [PMID: 19740981 DOI: 10.1128/jvi.01318-09] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ORF66p, a virion-associated varicella-zoster virus (VZV) protein, is a member of a conserved Alphaherpesvirinae kinase family with homology to herpes simplex virus US3 kinase. Expression of ORF66p in cells infected with VZV or an adenovirus expressing only ORF66p results in hyperphosphorylation of histone deacetylase 1 (HDAC1) and HDAC2. Mapping studies reveal that phosphorylation is at a unique conserved Ser residue in the C terminus of both HDACs. This modification requires an active kinase domain in ORF66p, as neither protein is phosphorylated in cells infected with VZV lacking kinase activity. However, hyperphosphorylation appears to occur indirectly, as within the context of in vitro kinase reactions, purified ORF66p phosphorylates a peptide derived from ORF62p, a known substrate, but does not phosphorylate HDAC. These results support a model where ORF66p is necessary but not sufficient to effect hyperphosphorylation of HDAC1 and HDAC2.
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