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Gonzalez MM, Vizoso-Pinto MG, Erra-Balsells R, Gensch T, Cabrerizo FM. In Vitro Effect of 9,9'-Norharmane Dimer against Herpes Simplex Viruses. Int J Mol Sci 2024; 25:4966. [PMID: 38732185 PMCID: PMC11084892 DOI: 10.3390/ijms25094966] [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: 02/21/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
Herpes simplex virus (HSV) infections are highly widespread among humans, producing symptoms ranging from ulcerative lesions to severe diseases such as blindness and life-threatening encephalitis. At present, there are no vaccines available, and some existing antiviral treatments can be ineffective or lead to adverse effects. As a result, there is a need for new anti-HSV drugs. In this report, the in vitro anti-HSV effect of 9,9'-norharmane dimer (nHo-dimer), which belongs to the β-carboline (βC) alkaloid family, was evaluated. The dimer exhibited no virucidal properties and did not impede either the attachment or penetration steps of viral particles. The antiviral effect was only exerted under the constant presence of the dimer in the incubation media, and the mechanism of action was found to involve later events of virus infection. Analysis of fluorescence lifetime imaging data showed that the nHo-dimer internalized well into the cells when present in the extracellular incubation medium, with a preferential accumulation into perinuclear organelles including mitochondria. After washing the host cells with fresh medium free of nHo-dimer, the signal decreased, suggesting the partial release of the compound from the cells. This agrees with the observation that the antiviral effect is solely manifested when the alkaloid is consistently present in the incubation media.
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Affiliation(s)
- María Micaela Gonzalez
- Instituto Tecnológico de Chascomús (CONICET-UNSAM), Av. Intendente Marino Km 8.2, CC 164 (B7130IWA), Chascomús 7130, Argentina;
- Escuela de Bio y Nanotecnologías (UNSAM), San Martín 1650, Argentina
| | - Maria Guadalupe Vizoso-Pinto
- Max von Pettenkofer Institute, Virology, National Reference Center for Retroviruses, Faculty of Medicine, LMU, D-80336 Munich, Germany;
- Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, San Miguel de Tucumán 4000, Argentina
- Laboratorio Central de Cs. Básicas, Facultad de Medicina, Universidad Nacional de Tucumán, Tucumán 4000, Argentina
| | - Rosa Erra-Balsells
- Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, 3er P., Ciudad Universitaria, Buenos Aires 1428, Argentina;
- Centro de Investigación en Hidratos de Carbono (CIHIDECAR), CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Naturales Pabellón II, 3er P. Ciudad Universitaria, Buenos Aires 1428, Argentina
| | - Thomas Gensch
- Institute of Biological Information Processing 1 (IBI-1; Molecular and Cellular Physiology), Forschungszentrum Jülich, Wilhelm-Jonen-Straße, 52428 Jülich, Germany
| | - Franco M. Cabrerizo
- Instituto Tecnológico de Chascomús (CONICET-UNSAM), Av. Intendente Marino Km 8.2, CC 164 (B7130IWA), Chascomús 7130, Argentina;
- Escuela de Bio y Nanotecnologías (UNSAM), San Martín 1650, Argentina
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2
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Jan Fada B, Guha U, Zheng Y, Reward E, Kaadi E, Dourra A, Gu H. A Novel Recognition by the E3 Ubiquitin Ligase of HSV-1 ICP0 Enhances the Degradation of PML Isoform I to Prevent ND10 Reformation in Late Infection. Viruses 2023; 15:v15051070. [PMID: 37243155 DOI: 10.3390/v15051070] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/24/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Upon viral entry, components of ND10 nuclear bodies converge with incoming DNA to repress viral expression. The infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) contains a RING-type E3 ubiquitin ligase that targets the ND10 organizer, PML, for proteasomal degradation. Consequently, ND10 components are dispersed and viral genes are activated. Previously, we reported that ICP0 E3 differentiates two similar substrates, PML isoforms I and II, and demonstrated that SUMO-interaction has profound regulatory effects on PML II degradation. In the present study, we investigated elements that regulate the PML I degradation and found that: (i) two regions of ICP0 flanking the RING redundantly facilitate the degradation of PML I; (ii) downstream of the RING, the SUMO-interaction motif located at residues 362-364 (SIM362-364) targets the SUMOylated PML I in the same manner as that of PML II; (iii) upstream of the RING, the N-terminal residues 1-83 mediate PML I degradation regardless of its SUMOylation status or subcellular localization; (iv) the reposition of residues 1-83 to downstream of the RING does not affect its function in PML I degradation; and (v) the deletion of 1-83 allows the resurgence of PML I and reformation of ND10-like structures late in HSV-1 infection. Taken together, we identified a novel substrate recognition specific for PML I, by which ICP0 E3 enforces a continuous PML I degradation throughout the infection to prevent the ND10 reformation.
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Affiliation(s)
- Behdokht Jan Fada
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Udayan Guha
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Yi Zheng
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Eleazar Reward
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Elie Kaadi
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Ayette Dourra
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Haidong Gu
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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3
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Hou F, Sun Z, Deng Y, Chen S, Yang X, Ji F, Zhou M, Ren K, Pan D. Interactome and Ubiquitinome Analyses Identify Functional Targets of Herpes Simplex Virus 1 Infected Cell Protein 0. Front Microbiol 2022; 13:856471. [PMID: 35516420 PMCID: PMC9062659 DOI: 10.3389/fmicb.2022.856471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) can productively infect multiple cell types and establish latent infection in neurons. Infected cell protein 0 (ICP0) is an HSV-1 E3 ubiquitin ligase crucial for productive infection and reactivation from latency. However, our knowledge about its targets especially in neuronal cells is limited. We confirmed that, like in non-neuronal cells, ICP0-null virus exhibited major replication defects in primary mouse neurons and Neuro-2a cells. We identified many ICP0-interacting proteins in Neuro-2a cells, 293T cells, and human foreskin fibroblasts by mass spectrometry-based interactome analysis. Co-immunoprecipitation assays validated ICP0 interactions with acyl-coenzyme A thioesterase 8 (ACOT8), complement C1q binding protein (C1QBP), ovarian tumour domain-containing protein 4 (OTUD4), sorting nexin 9 (SNX9), and vimentin (VIM) in both Neuro-2a and 293T cells. Overexpression and knockdown experiments showed that SNX9 restricted replication of an ICP0-null but not wild-type virus in Neuro-2a cells. Ubiquitinome analysis by immunoprecipitating the trypsin-digested ubiquitin reminant followed by mass spectrometry identified numerous candidate ubiquitination substrates of ICP0 in infected Neuro-2a cells, among which OTUD4 and VIM were novel substrates confirmed to be ubiquitinated by transfected ICP0 in Neuro-2a cells despite no evidence of their degradation by ICP0. Expression of OTUD4 was induced independently of ICP0 during HSV-1 infection. Overexpressed OTUD4 enhanced type I interferon expression during infection with the ICP0-null but not wild-type virus. In summary, by combining two proteomic approaches followed by confirmatory and functional experiments, we identified and validated multiple novel targets of ICP0 and revealed potential restrictive activities of SNX9 and OTUD4 in neuronal cells.
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Affiliation(s)
- Fujun Hou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
| | - Zeyu Sun
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Jinan Microecological Biomedicine Shandong Laboratory, Jinan, China
| | - Yue Deng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
| | - Siyu Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiyuan Yang
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
| | - Feiyang Ji
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Menghao Zhou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Keyi Ren
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Dongli Pan
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Medical Microbiology and Parasitology, Zhejiang University School of Medicine, Hangzhou, China
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4
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St. Leger AJ, Koelle DM, Kinchington PR, Verjans GMGM. Local Immune Control of Latent Herpes Simplex Virus Type 1 in Ganglia of Mice and Man. Front Immunol 2021; 12:723809. [PMID: 34603296 PMCID: PMC8479180 DOI: 10.3389/fimmu.2021.723809] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/26/2021] [Indexed: 12/28/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) is a prevalent human pathogen. HSV-1 genomes persist in trigeminal ganglia neuronal nuclei as chromatinized episomes, while epithelial cells are typically killed by lytic infection. Fluctuations in anti-viral responses, broadly defined, may underlay periodic reactivations. The ganglionic immune response to HSV-1 infection includes cell-intrinsic responses in neurons, innate sensing by several cell types, and the infiltration and persistence of antigen-specific T-cells. The mechanisms specifying the contrasting fates of HSV-1 in neurons and epithelial cells may include differential genome silencing and chromatinization, dictated by variation in access of immune modulating viral tegument proteins to the cell body, and protection of neurons by autophagy. Innate responses have the capacity of recruiting additional immune cells and paracrine activity on parenchymal cells, for example via chemokines and type I interferons. In both mice and humans, HSV-1-specific CD8 and CD4 T-cells are recruited to ganglia, with mechanistic studies suggesting active roles in immune surveillance and control of reactivation. In this review we focus mainly on HSV-1 and the TG, comparing and contrasting where possible observational, interventional, and in vitro studies between humans and animal hosts.
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Affiliation(s)
- Anthony J. St. Leger
- Department of Ophthalmology and Immunology, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - David M. Koelle
- Department of Medicine, University of Washington, Seattle, WA, United States
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, United States
- Department of Global Health, University of Washington, Seattle, WA, United States
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
- Benaroya Research Institute, Seattle, WA, United States
| | - Paul R. Kinchington
- Department of Ophthalmology and Molecular Microbiology and Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
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5
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Mei XX, Lei SS, Xu L, Wu S, Gu HP, Du Y, Zhao T, Xie GQ, Fan YS, Pan XP, Bao J. Herpes simplex virus type I-infected disorders alter the balance between Treg and Th17 cells in recurrent herpes labialis patients. Int J Immunopathol Pharmacol 2021; 34:2058738420933099. [PMID: 32735468 PMCID: PMC7401041 DOI: 10.1177/2058738420933099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Recurrent herpes labialis (RHL) is a common skin disease that is often caused by herpes simplex virus type I (HSV-1), but its immunology and pathogenesis remain unclear. The balance of Th17/Treg cells is crucial for maintaining immune homeostasis. This study aimed to investigate whether the balance of Th17/Treg cells and related cytokines may be a determinant occurrence in patients with RHL. This is a clinical experimental research based on clinical observation and analysis. We collected RHL patients from the outpatient clinic of the Department of Dermatology of Zhejiang Chinese Medical University (Hangzhou, China) in 2017, conducted questionnaire survey and signed informed consent. Peripheral blood was collected from 30 patients with RHL and 30 healthy volunteers. Flow cytometry was used to detect the percentages of Treg cells and Th17 cells. Protein microarrays coated with 20 cytokines related to T-cell subsets were performed. Enzyme-linked immunosorbent assay (ELISA) assay was conducted to further verify the expression levels of the cytokines that were screened by protein microarrays. Percentages of Th17/Treg cells in peripheral blood of RHL patients were significantly increased compared to those in healthy volunteers. The fold changes of GM-CSF, IL-4, TGF-β, IL-12, IL-10, IL-17F, and TNF-α were significantly increased compared with healthy volunteers. In addition, the expression of IL-4, IL-10, and TGF-β in the serum of RHL patients increased significantly. Our results indicated an imbalance of Th17/Treg cells in RHL, and this imbalance is probably an important factor in the occurrence, development, and recovery of RHL.
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Affiliation(s)
- Xian-Xian Mei
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Shan-Shan Lei
- Zhejiang Academy of Traditional Chinese Medicine, Hangzhou, China
| | - Li Xu
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Shan Wu
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Huan-Peng Gu
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Yu Du
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Ting Zhao
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Guan-Qun Xie
- Zhejiang Chinese Medical University, Hangzhou, China
| | | | - Xiao-Ping Pan
- Zhejiang Chinese Medical University, Hangzhou, China
| | - Jie Bao
- Zhejiang Chinese Medical University, Hangzhou, China
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6
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Immune Response to Herpes Simplex Virus Infection and Vaccine Development. Vaccines (Basel) 2020; 8:vaccines8020302. [PMID: 32545507 PMCID: PMC7350219 DOI: 10.3390/vaccines8020302] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/29/2020] [Accepted: 06/08/2020] [Indexed: 12/20/2022] Open
Abstract
Herpes simplex virus (HSV) infections are among the most common viral infections and usually last for a lifetime. The virus can potentially be controlled with vaccines since humans are the only known host. However, despite the development and trial of many vaccines, this has not yet been possible. This is normally attributed to the high latency potential of the virus. Numerous immune cells, particularly the natural killer cells and interferon gamma and pathways that are used by the body to fight HSV infections have been identified. On the other hand, the virus has developed different mechanisms, including using different microRNAs to inhibit apoptosis and autophagy to avoid clearance and aid latency induction. Both traditional and new methods of vaccine development, including the use of live attenuated vaccines, replication incompetent vaccines, subunit vaccines and recombinant DNA vaccines are now being employed to develop an effective vaccine against the virus. We conclude that this review has contributed to a better understanding of the interplay between the immune system and the virus, which is necessary for the development of an effective vaccine against HSV.
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7
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Gu H, Jan Fada B. Specificity in Ubiquitination Triggered by Virus Infection. Int J Mol Sci 2020; 21:E4088. [PMID: 32521668 PMCID: PMC7313089 DOI: 10.3390/ijms21114088] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/03/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023] Open
Abstract
Ubiquitination is a prominent posttranslational modification, in which the ubiquitin moiety is covalently attached to a target protein to influence protein stability, interaction partner and biological function. All seven lysine residues of ubiquitin, along with the N-terminal methionine, can each serve as a substrate for further ubiquitination, which effectuates a diverse combination of mono- or poly-ubiquitinated proteins with linear or branched ubiquitin chains. The intricately composed ubiquitin codes are then recognized by a large variety of ubiquitin binding domain (UBD)-containing proteins to participate in the regulation of various pathways to modulate the cell behavior. Viruses, as obligate parasites, involve many aspects of the cell pathways to overcome host defenses and subjugate cellular machineries. In the virus-host interactions, both the virus and the host tap into the rich source of versatile ubiquitination code in order to compete, combat, and co-evolve. Here, we review the recent literature to discuss the role of ubiquitin system as the infection progresses in virus life cycle and the importance of ubiquitin specificity in the regulation of virus-host relation.
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Affiliation(s)
- Haidong Gu
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA;
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8
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Effect of SUMO-SIM Interaction on the ICP0-Mediated Degradation of PML Isoform II and Its Associated Proteins in Herpes Simplex Virus 1 Infection. J Virol 2020; 94:JVI.00470-20. [PMID: 32295906 DOI: 10.1128/jvi.00470-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 04/01/2020] [Indexed: 12/22/2022] Open
Abstract
ND10 nuclear bodies, as part of the intrinsic defenses, impose repression on incoming DNA. Infected cell protein 0 (ICP0), an E3 ubiquitin ligase of herpes simplex virus 1 (HSV-1), can derepress viral genes by degrading ND10 organizers to disrupt ND10. These events are part of the initial tug of war between HSV-1 and host, which determines the ultimate outcome of infection. Previously, we reported that ICP0 differentially recognizes promyelocytic leukemia (PML) isoforms. ICP0 depends on a SUMO-interaction motif located at residues 362 to 364 (SIM362-364) to trigger the degradation of PML isoforms II, IV, and VI, while using a bipartite sequence flanking the RING domain to degrade PML I. In this study, we investigated how the SUMO-SIM interaction regulates the degradation of PML II and PML II-associated proteins in ND10. We found that (i) the same regulatory mechanism for PML II degradation was detected in cells permissive or nonpermissive to the ICP0-null virus; (ii) the loss of a single SIM362-364 motif was restored by the presence of four consecutive SIMs from RNF4, but was not rescued by only two of the RNF4 SIMs; (iii) the loss of three C-terminal SIMs of ICP0 was fully restored by four RNF4 SIMs and also partially rescued by two RNF4 SIMs; and (iv) a PML II mutant lacking both lysine SUMOylation and SIM was not recognized by ICP0 for degradation, but was localized to ND10 and mitigated the degradation of other ND10 components, leading to delayed viral production. Taken together, SUMO regulates ICP0 substrate recognition via multiple fine-tuned mechanisms in HSV-1 infection.IMPORTANCE HSV-1 ICP0 is a multifunctional immediate early protein key to effective replication in the HSV-1 lytic cycle and reactivation in the latent cycle. ICP0 transactivates gene expression by orchestrating an overall mitigation in host intrinsic/innate restrictions. How ICP0 coordinates its multiple active domains and its diverse protein-protein interactions is a key question in understanding the HSV-1 life cycle and pathogenesis. The present study focuses on delineating the regulatory effects of the SUMO-SIM interaction on ICP0 E3 ubiquitin ligase activity regarding PML II degradation. For the first time, we discovered the importance of multivalency in the PML II-ICP0 interaction network and report the involvement of different regulatory mechanisms in PML II recognition by ICP0 in HSV-1 infection.
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9
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Alandijany T. Host Intrinsic and Innate Intracellular Immunity During Herpes Simplex Virus Type 1 (HSV-1) Infection. Front Microbiol 2019; 10:2611. [PMID: 31781083 PMCID: PMC6856869 DOI: 10.3389/fmicb.2019.02611] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/28/2019] [Indexed: 12/20/2022] Open
Abstract
When host cells are invaded by viruses, they deploy multifaceted intracellular defense mechanisms to control infections and limit the damage they may cause. Host intracellular antiviral immunity can be classified into two main branches: (i) intrinsic immunity, an interferon (IFN)-independent antiviral response mediated by constitutively expressed cellular proteins (so-called intrinsic host restriction factors); and (ii) innate immunity, an IFN-dependent antiviral response conferred by IFN-stimulated gene (ISG) products, which are (as indicated by their name) upregulated in response to IFN secretion following the recognition of pathogen-associated molecular patterns (PAMPs) by host pattern recognition receptors (PRRs). Recent evidence has demonstrated temporal regulation and specific viral requirements for the induction of these two arms of immunity during herpes simplex virus type 1 (HSV-1) infection. Moreover, they exert differential antiviral effects to control viral replication. Although they are distinct from one another, the words "intrinsic" and "innate" have been interchangeably and/or simultaneously used in the field of virology. Hence, the aims of this review are to (1) elucidate the current knowledge about host intrinsic and innate immunity during HSV-1 infection, (2) clarify the recent advances in the understanding of their regulation and address the distinctions between them with respect to their induction requirements and effects on viral infection, and (3) highlight the key roles of the viral E3 ubiquitin ligase ICP0 in counteracting both aspects of immunity. This review emphasizes that intrinsic and innate immunity are temporally and functionally distinct arms of host intracellular immunity during HSV-1 infection; the findings are likely pertinent to other clinically important viral infections.
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Affiliation(s)
- Thamir Alandijany
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
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10
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The ICP0 Protein of Herpes Simplex Virus 1 (HSV-1) Downregulates Major Autophagy Adaptor Proteins Sequestosome 1 and Optineurin during the Early Stages of HSV-1 Infection. J Virol 2019; 93:JVI.01258-19. [PMID: 31375597 DOI: 10.1128/jvi.01258-19] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 07/31/2019] [Indexed: 02/06/2023] Open
Abstract
Herpes simplex virus 1 (HSV-1) infects mucosal epithelial cells and establishes lifelong infections in sensory neurons. Following reactivation, the virus is transferred anterograde to the initial site of infection or to sites innervated by infected neurons, causing vesicular lesions. Upon immunosuppression, frequent HSV-1 reactivation can cause severe diseases, such as blindness and encephalitis. Autophagy is a process whereby cell components are recycled, but it also serves as a defense mechanism against pathogens. HSV-1 is known to combat autophagy through the functions of the γ134.5 protein, which prevents formation of the autophagophore by binding to Beclin 1, a key factor involved in the elongation of the isolation membrane, and by redirecting the protein phosphatase 1α (PP1α) to dephosphorylate the translation initiation factor 2α (eIF2α) to prevent host translational shutoff. Other viral proteins that counteract innate immunity negatively impact autophagy. Here, we present a novel strategy of HSV-1 to evade the host through the downregulation of the autophagy adaptor protein sequestosome (p62/SQSTM1) and of the mitophagy adaptor optineurin (OPTN). This down-modulation occurs during the early steps of the infection. We also found that infected cell protein 0 (ICP0) of the virus mediates the down-modulation of the two autophagy adaptors in a mechanism independent of its E3 ubiquitin ligase activity. Cells depleted of either p62 or OPTN were able to mount greater antiviral responses, whereas cells expressing exogenous p62 displayed decreased virus yields. We conclude that downregulation of p62/SQSTM1 and OPTN is a viral strategy to counteract the host.IMPORTANCE Autophagy is a homeostatic mechanism of cells to recycle components, as well as a defense mechanism to get rid of pathogens. Strategies that HSV-1 has developed to counteract autophagy have been described and involve inhibition of autophagosome formation or indirect mechanisms. Here, we present a novel mechanism that involves downregulation of two major autophagy adaptor proteins, sequestosome 1 (p62/SQSTM1) and optineurin (OPTN). These findings generate the question of why the virus targets two major autophagy adaptors if it has mechanisms to block autophagosome formation. P62/SQSTM1 and OPTN proteins have pleiotropic functions, including regulation of innate immunity, inflammation, protein sorting, and chromatin remodeling. The decrease in virus yields in the presence of exogenous p62/SQSTM1 suggests that these adaptors have an antiviral function. Thus, HSV-1 may have developed multiple strategies to incapacitate autophagy to ensure replication. Alternatively, the virus may target another antiviral function of these proteins.
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11
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Mancuso R, Sicurella M, Agostini S, Marconi P, Clerici M. Herpes simplex virus type 1 and Alzheimer's disease: link and potential impact on treatment. Expert Rev Anti Infect Ther 2019; 17:715-731. [PMID: 31414935 DOI: 10.1080/14787210.2019.1656064] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Introduction: Alzheimer's disease (AD), the most common form of dementia worldwide, is a multifactorial disease with a still unknown etiology. Herpes simplex virus 1 (HSV-1) has long been suspected to be one of the factors involved in the pathogenesis of the disease. Areas covered: We review the literature focusing on viral characteristics of HSV-1, the mechanisms this virus uses to infect neural cells, its interaction with the host immune system and genetic background and summarizes results and research that support the hypothesis of an association between AD and HSV-1. The possible usefulness of virus-directed pharmaceutical approaches as potential treatments for AD will be discussed as well. Expert opinion: We highlight crucial aspects that must be addressed to clarify the possible role of HSV-1 in the pathogenesis of the disease, and to allow the design of new therapeutical approaches for AD.
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Affiliation(s)
| | | | | | - Peggy Marconi
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara , Ferrara , Italy
| | - Mario Clerici
- IRCCS Fondazione Don Carlo Gnocchi , Milan , Italy.,Department of Pathophysiology and Transplantation, University of Milan , Milan , Italy
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12
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Biogenesis of Extracellular Vesicles during Herpes Simplex Virus 1 Infection: Role of the CD63 Tetraspanin. J Virol 2019; 93:JVI.01850-18. [PMID: 30355691 DOI: 10.1128/jvi.01850-18] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/20/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) infections afflict more than 80% of the population worldwide. The virus primarily infects mucoepithelial cells and establishes latent reservoirs in neurons in sensory ganglia. Frequent reactivation has been linked to severe diseases, especially in immunocompromised individuals. Earlier, we reported that viral and host factors are packaged in extracellular vesicles (EVs) and delivered to uninfected cells, where they activate antiviral responses and restrict virus infection. Here, we interrogated the effect of HSV-1 infection on EV biogenesis. We found that HSV-1 infection causes a decrease in the amount of intracellular CD63 protein with a concomitant increase in extracellular CD63. This observation correlates with our previous finding that infected cells release more CD63-positive EVs than uninfected cells. The stimulation of CD63 exocytosis requires virus replication. CD63 is a member of the tetraspanin family of proteins that traffics between the plasma membrane and endosomal compartments and has a role in sorting cargo into the EVs. Previously, we reported that in cells depleted of CD63, HSV-1 virus yields increased, and here we provide data showing that in cells overexpressing CD63, HSV-1 virus yields decreased. Taken together, our data indicate that CD63 negatively impacts HSV-1 infection and that the CD63-positive EVs could control the dissemination of the virus in the host. Perhaps EV release by HSV-1-infected cells is a mechanism that controls virus dissemination.IMPORTANCE Intercellular communication, especially in neurons, largely relies on EVs, and modulation of EVs is known to impact physiological processes. Here, we present evidence that HSV-1 infection causes major alterations in the biogenesis of EVs, including an increase in their number and an increase in the CD63-positive population of EVs. These alterations result in an enrichment of the milieu of infection with EVs carrying signatures from infected cells. In addition to changes in the origin and type, EVs released by infected cells have differences in cargo, as they carry viral and host factors determined by the virus. The tetraspanin CD63 negatively impacts the infection, as demonstrated by CD63-knockdown and overexpression assays. A proposed mechanism involves the activation of antiviral responses in cells receiving CD63-positive EVs released by infected cells. Overall, HSV-1 causes major alterations in EVs that could contribute to HSV-1 persistence and pathogenesis.
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Samrat SK, Gu H. Temporal Analysis of the Nuclear-to-cytoplasmic Translocation of a Herpes Simplex Virus 1 Protein by Immunofluorescent Confocal Microscopy. J Vis Exp 2018. [PMID: 30451237 DOI: 10.3791/58504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is an immediate early protein containing a RING-type E3 ubiquitin ligase. It is responsible for the proteasomal degradation of host restrictive factors and the subsequent viral gene activation. ICP0 contains a canonical nuclear localization sequence (NLS). It enters the nucleus immediately after de novo synthesis and executes its anti-host defense functions mainly in the nucleus. However, later in infection, ICP0 is found solely in the cytoplasm, suggesting the occurrence of a nuclear-to-cytoplasmic translocation during HSV-1 infection. Presumably ICP0 translocation enables ICP0 to modulate its functions according to its subcellular locations at different infection phases. In order to delineate the biological function and regulatory mechanism of ICP0 nuclear-to-cytoplasmic translocation, we modified an immunofluorescent microscopy method to monitor ICP0 trafficking during HSV-1 infection. This protocol involves immunofluorescent staining, confocal microscope imaging, and nuclear vs. cytoplasmic distribution analysis. The goal of this protocol is to adapt the steady state confocal images taken in a time course into a quantitative documentation of ICP0 movement throughout the lytic infection. We propose that this method can be generalized to quantitatively analyze nuclear vs. cytoplasmic localization of other viral or cellular proteins without involving live imaging technology.
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Affiliation(s)
| | - Haidong Gu
- Department of Biological Sciences, Wayne State University;
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Affiliation(s)
- Haidong Gu
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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Characterization of Elements Regulating the Nuclear-to-Cytoplasmic Translocation of ICP0 in Late Herpes Simplex Virus 1 Infection. J Virol 2018; 92:JVI.01673-17. [PMID: 29093084 DOI: 10.1128/jvi.01673-17] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/24/2017] [Indexed: 01/16/2023] Open
Abstract
Infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is an immediate early protein containing a RING-type E3 ubiquitin ligase. It targets several host factors for proteasomal degradation and subsequently activates viral expression. ICP0 has a nuclear localization sequence and functions in the nucleus early during infection. However, later in infection, ICP0 is found solely in the cytoplasm. The molecular mechanism and biological function of the ICP0 nuclear-to-cytoplasmic translocation are not well understood. In this study, we sought to characterize elements important for this translocation. We found that (i) in human embryonic lung fibroblast (HEL) cells, ICP0 C-terminal residues 741 to 775 were necessary but not sufficient for the nuclear-to-cytoplasmic translocation; (ii) the loss of ICP0 E3 ubiquitin ligase activity, which led to defective viral replication in nonpermissive cells, also caused mutant ICP0 to be retained in the nucleus of HEL cells; (iii) in permissive U2OS cells, however, ICP0 lacking E3 ligase activity was translocated to the cytoplasm at a pace faster than that of wild-type ICP0, suggesting that nuclear retention of ICP0 occurs in an ICP0 E3 ligase-dependent manner; and (iv) the ICP0 C terminus and late viral proteins cooperate in order to overcome nuclear retention and stimulate ICP0 cytoplasmic translocation. Taken together, less ICP0 nuclear retention may contribute to the permissiveness of U2OS cells to HSV-1 in the absence of functional ICP0.IMPORTANCE A distinct characteristic for eukaryotes is the compartmentalization of cell metabolic pathways, which allows greater efficiency and specificity of cellular functions. ICP0 of HSV-1 is a multifunctional viral protein that travels through different compartments as infection progresses. Its main regulatory functions are carried out in the nucleus, but it is translocated to the cytoplasm late during HSV-1 infection. To understand the biological significance of cytoplasmic ICP0 in HSV-1 infection, we investigated the potential players involved in this nuclear-to-cytoplasmic translocation. We found that there is a nuclear retention force in an ICP0 E3 ubiquitin ligase-dependent manner. In addition, we identified the C terminus of ICP0 as a cis element cooperating with late viral proteins to overcome the nuclear retention and stimulate the nuclear-to-cytoplasmic translocation of ICP0.
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A Tale of Two PMLs: Elements Regulating a Differential Substrate Recognition by the ICP0 E3 Ubiquitin Ligase of Herpes Simplex Virus 1. J Virol 2016; 90:10875-10885. [PMID: 27681131 DOI: 10.1128/jvi.01636-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 09/20/2016] [Indexed: 01/08/2023] Open
Abstract
Infected cell protein 0 (ICP0) of herpes simplex virus 1 (HSV-1) is an α gene product required for viral replication at low multiplicities of infection. Upon entry, nuclear domain 10 (ND10) converges at the incoming DNA and represses viral gene expression. ICP0 contains a RING-type E3 ubiquitin ligase that degrades the ND10 organizer PML and disperses ND10 to alleviate the repression. In the present study, we focused on understanding the regulation of ICP0 E3 ligase activity in the degradation of different ICP0 substrates. We report the following. (i) A SUMO interaction motif located at ICP0 residues 362 to 364 is required for the degradation of PML isoforms II, IV, and VI but not isoform I. This differentiation mechanism exists in both HEp-2 and U2OS cells, regardless of the cell's permissiveness to the ICP0-null virus. (ii) Physical interaction between SIM362-364 and PML II is necessary but not sufficient for PML II degradation. Both proximal sequences surrounding SIM362-364 and distal sequences located at the ICP0 C terminus enhance the degradation of PML II. (iii) The ICP0 C terminus is dispensable for PML I degradation. Instead, bipartite PML I binding domains located in the N-terminal half of ICP0 coordinate to promote the degradation of PML I. (iv) The stability of ICP0, but not its ND10 fusion ability, affects the rate of PML I degradation. Taken together, our results show that ICP0 uses at least two regulatory mechanisms to differentiate its substrates. The disparate recognition of the ICP0 E3 substrates may be related to the different roles these substrates may play in HSV-1 infection. IMPORTANCE Viruses have a limited genetic coding capacity but must encounter a multilayered comprehensive host defense. To establish a successful infection, viruses usually produce multifunctional proteins to coordinate the counteractions. Here we report that an HSV-1 protein, ICP0, can recognize individual host factors and target them differently for destruction. We identified elements that are important for the ICP0 E3 ubiquitin ligase to differentially recognize two of its substrates, PML I and PML II. This is the first study that has systematically investigated how ICP0 discriminates two similar molecules by very different mechanisms. This work lays the foundation for understanding the role of host defensive factors and the mechanisms viruses use to take advantage of some host proteins while destroying others.
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Xu X, Fan S, Zhou J, Zhang Y, Che Y, Cai H, Wang L, Guo L, Liu L, Li Q. The mutated tegument protein UL7 attenuates the virulence of herpes simplex virus 1 by reducing the modulation of α-4 gene transcription. Virol J 2016; 13:152. [PMID: 27618986 PMCID: PMC5020468 DOI: 10.1186/s12985-016-0600-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/12/2016] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND UL7, a tegument protein of Herpes Simplex Virus type I (HSV-1), is highly conserved in viral infection and proliferation and has an unknown mechanism of action. METHODS A HSV-1 UL7 mutant (UL7-MU) was constructed using the CRISPR-cas9 system. The replication rate and plaque morphology were used to analyze the biological characteristics of the wild-type (WT), UL7-MU and MU-complemented P1 viruses. The virulence of the viruses was evaluated in mice. Real-time RT-qPCR and ChIP assays were used to determine the expression levels of relevant genes. RESULTS The replication capacity of a recombinant virus (UL7-MU strain) was 10-fold lower than that of the WT strain. The neurovirulence and pathologic effect of the UL7-MU strain were attenuated in infected mice compared with the WT strain. In the latency model, the expression of latency-associated transcript (LAT) in the central nervous system (CNS) and trigeminal nerve was lower in UL7-MU-infected mice than in WT strain-infected mice. The transcription level of the immediate-early gene α-4 in UL7-MU-infected cells was reduced by approximately 2-fold compared with the clear transcriptional peak identified in WT strain-infected Vero cells within 7 h post-infection (p.i.). CONCLUSION By modulating the transcription of the α-4 gene, UL7 may be involved in transcriptional regulation through its interaction with the transcript complex structure of the viral genome during HSV-1 infection.
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Affiliation(s)
- Xingli Xu
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Shengtao Fan
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Jienan Zhou
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Ying Zhang
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Yanchun Che
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Hongzhi Cai
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Lichun Wang
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Lei Guo
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Longding Liu
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China
| | - Qihan Li
- Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Yunnan Key Laboratory of Vaccine Research and Development of Severe Infectious Disease, Kunming, Yunnan, China.
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Sawtell NM, Thompson RL. De Novo Herpes Simplex Virus VP16 Expression Gates a Dynamic Programmatic Transition and Sets the Latent/Lytic Balance during Acute Infection in Trigeminal Ganglia. PLoS Pathog 2016; 12:e1005877. [PMID: 27607440 PMCID: PMC5015900 DOI: 10.1371/journal.ppat.1005877] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/17/2016] [Indexed: 11/19/2022] Open
Abstract
The life long relationship between herpes simplex virus and its host hinges on the ability of the virus to aggressively replicate in epithelial cells at the site of infection and transport into the nervous system through axons innervating the infection site. Interaction between the virus and the sensory neuron represents a pivot point where largely unknown mechanisms lead to a latent or a lytic infection in the neuron. Regulation at this pivot point is critical for balancing two objectives, efficient widespread seeding of the nervous system and host survival. By combining genetic and in vivo in approaches, our studies reveal that the balance between latent and lytic programs is a process occurring early in the trigeminal ganglion. Unexpectedly, activation of the latent program precedes entry into the lytic program by 12 -14hrs. Importantly, at the individual neuronal level, the lytic program begins as a transition out of this acute stage latent program and this escape from the default latent program is regulated by de novo VP16 expression. Our findings support a model in which regulated de novo VP16 expression in the neuron mediates entry into the lytic cycle during the earliest stages of virus infection in vivo. These findings support the hypothesis that the loose association of VP16 with the viral tegument combined with sensory axon length and transport mechanisms serve to limit arrival of virion associated VP16 into neuronal nuclei favoring latency. Further, our findings point to specialized features of the VP16 promoter that control the de novo expression of VP16 in neurons and this regulation is a key component in setting the balance between lytic and latent infections in the nervous system. Herpes simplex virus remains a significant human pathogen associated with extensive acute and chronic disease in humans worldwide. The virus invades the peripheral and central nervous systems where it replicates but also establishes life-long latent infections in neurons. Two distinct viral transcriptional programs support these distinct lifestyles, but how entry into either the lytic or latent programs is regulated in the neuron is not understood. This process is fundamentally important to a virus with the capacity to be extremely virulent, in balancing two objectives, efficient widespread seeding of the nervous system and host survival. In this report, we provide new insight into this regulation and data that support a novel model in which virus transported into the neuron from the body surface enters the latent program by default. In a subset of these, there is a transition into the lytic cycle, which requires VP16 transactivation and is gated by a region in the VP16 promoter. Thus, HSV takes advantage of the anatomy and axonal transport systems in sensory neurons so that VP16 is left behind and latency is favored, while features of the VP16 promoter insure adequate virus spread in the nervous system and maximized latent infections.
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Affiliation(s)
- Nancy M. Sawtell
- Department of Pediatrics, Division of Infectious Diseases, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- * E-mail: (NMS); (RLT)
| | - Richard L. Thompson
- Department of Molecular Genetics, Microbiology, and Biochemistry, University of Cincinnati School of Medicine, Cincinnati, Ohio, United States of America
- * E-mail: (NMS); (RLT)
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Sawtell NM, Thompson RL. Herpes simplex virus and the lexicon of latency and reactivation: a call for defining terms and building an integrated collective framework. F1000Res 2016; 5:F1000 Faculty Rev-2038. [PMID: 27610228 PMCID: PMC4995687 DOI: 10.12688/f1000research.8886.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/17/2016] [Indexed: 11/25/2022] Open
Abstract
The field of herpes simplex virus (HSV) latency and reactivation has been marked by controversy, which is not unexpected considering the complexities of the biology involved. While controversy is an important tool for digging to the bottom of difficult issues, we propose that unproductive conflict in the field arises in part from poorly defined terminology and the need for a collective framework. The uses of advanced global molecular and next-generation sequencing approaches and an increasing array of in vitro model systems have provided new molecular-level insights into HSV latency and reactivation, with the promise of expanding our concepts of these processes. However, our current framework and language are inadequate to effectively integrate new data streams into the established theories. In this brief perspective, we look back into the past to examine when and how the lexicon of HSV latency and reactivation arose in the literature and its evolution. We propose to open a dialogue among investigators for the purpose of updating and clearly defining terms used to describe these processes and to build a collective integrated framework to move our field forward.
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Affiliation(s)
- Nancy M. Sawtell
- Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Richard L. Thompson
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH, USA
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Gu H, Zheng Y. Role of ND10 nuclear bodies in the chromatin repression of HSV-1. Virol J 2016; 13:62. [PMID: 27048561 PMCID: PMC4822283 DOI: 10.1186/s12985-016-0516-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 03/28/2016] [Indexed: 01/09/2023] Open
Abstract
Herpes simplex virus (HSV) is a neurotropic virus that establishes lifelong latent infection in human ganglion sensory neurons. This unique life cycle necessitates an intimate relation between the host defenses and virus counteractions over the long course of infection. Two important aspects of host anti-viral defense, nuclear substructure restriction and epigenetic chromatin regulation, have been intensively studied in the recent years. Upon viral DNA entering the nucleus, components of discrete nuclear bodies termed nuclear domain 10 (ND10), converge at viral DNA and place restrictions on viral gene expression. Meanwhile the infected cell mobilizes its histones and histone-associated repressors to force the viral DNA into nucleosome-like structures and also represses viral transcription. Both anti-viral strategies are negated by various HSV countermeasures. One HSV gene transactivator, infected cell protein 0 (ICP0), is a key player in antagonizing both the ND10 restriction and chromatin repression. On one hand, ICP0 uses its E3 ubiquitin ligase activity to target major ND10 components for proteasome-dependent degradation and thereafter disrupts the ND10 nuclear bodies. On the other hand, ICP0 participates in de-repressing the HSV chromatin by changing histone composition or modification and therefore activates viral transcription. Involvement of a single viral protein in two seemingly different pathways suggests that there is coordination in host anti-viral defense mechanisms and also cooperation in viral counteraction strategies. In this review, we summarize recent advances in understanding the role of chromatin regulation and ND10 dynamics in both lytic and latent HSV infection. We focus on the new observations showing that ND10 nuclear bodies play a critical role in cellular chromatin regulation. We intend to find the connections between the two major anti-viral defense pathways, chromatin remodeling and ND10 structure, in order to achieve a better understanding of how host orchestrates a concerted defense and how HSV adapts with and overcomes the host immunity.
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Affiliation(s)
- Haidong Gu
- Department of Biological Sciences, Wayne State University, 4117 Biological Science Building, 5047 Gullen Mall, Detroit, MI, 48202, USA.
| | - Yi Zheng
- Department of Biological Sciences, Wayne State University, 4117 Biological Science Building, 5047 Gullen Mall, Detroit, MI, 48202, USA
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