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Pei J, Tian Y, Ye W, Han J, Dang Y, Cheng T, Wang W, Zhao Y, Ye W, Huangfu S, Li Y, Zhang F, Lei Y, Qian A. A novel recombinant ORF7-siRNA delivered by flexible nano-liposomes inhibits varicella zoster virus infection. Cell Biosci 2023; 13:167. [PMID: 37700336 PMCID: PMC10496174 DOI: 10.1186/s13578-023-01108-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 08/18/2023] [Indexed: 09/14/2023] Open
Abstract
BACKGROUND Varicella zoster virus (VZV), which is a human restricted alpha-herpesvirus, causes varicella (chickenpox) and zoster (shingles). The subsequent post-herpetic neuralgia (PHN) due to VZV infection is excruciating for most patients. Thus, developing specific therapeutics against VZV infection is imperative. RNA interference (RNAi) represents an effective approach for alternative antiviral therapy. This study aimed to develop a novel anti-VZV therapeutics based on RNAi. RESULTS In this study, we screened and found the open reading frame 7 (ORF7) of the VZV genome was an ideal antiviral target based on RNAi. Therefore, a novel siRNA targeting ORF7 (si-ORF7) was designed to explore the potential of RNAi antiviral treatment strategy toward VZV. We used a bio-engineering approach to manufacture recombinant siRNA agents with high yield in E. coli. Then, the efficacy of recombinant ORF7-siRNA (r/si-ORF7) in inhibiting VZV infection both in cellular level and 3D human epidermal skin model was evaluated. The r/si-ORF7 was proved to inhibit the VZV replication and reduce the virus copy numbers significantly in vitro. Furthermore, flexible nano-liposomes were established to deliver r/si-ORF7 to 3D human epidermal skin model and found r/si-ORF7 also could inhibit the VZV infection, thus maintaining normal skin morphology. CONCLUSIONS Taken together, our results highlighted that transdermal administration of antiviral r/si-ORF7 was a promising therapeutic strategy for functional cure of VZV infection.
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Affiliation(s)
- Jiawei Pei
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Ye Tian
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Wei Ye
- Department of Microbiology, School of Preclinical Medicine, Airforce Medical University: Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Jiangfan Han
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Yamei Dang
- Department of Microbiology, School of Preclinical Medicine, Airforce Medical University: Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Tong Cheng
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Institute of Diagnostics and Vaccine Development in Infectious Diseases, School of Life Sciences, School of Public Health, Xiamen University, Xiamen, China
| | - Wei Wang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, National Institute of Diagnostics and Vaccine Development in Infectious Diseases, School of Life Sciences, School of Public Health, Xiamen University, Xiamen, China
| | - Yipu Zhao
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Weiliang Ye
- Department of Pharmaceutics, School of Pharmacy, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shuyuan Huangfu
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China
| | - Yu Li
- Institute of Medical Research, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
| | - Fanglin Zhang
- Department of Microbiology, School of Preclinical Medicine, Airforce Medical University: Fourth Military Medical University, Xi'an, Shaanxi, China.
| | - Yingfeng Lei
- Department of Microbiology, School of Preclinical Medicine, Airforce Medical University: Fourth Military Medical University, Xi'an, Shaanxi, China.
| | - Airong Qian
- key Lab for Space Biosciences and Biotechnology, School of Life Science, Northwestern Polytechnical University, Xi'an, Shaanxi, China.
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Chang K, Majmudar H, Tandon R, Volin MV, Tiwari V. Induction of Filopodia During Cytomegalovirus Entry Into Human Iris Stromal Cells. Front Microbiol 2022; 13:834927. [PMID: 35450284 PMCID: PMC9018114 DOI: 10.3389/fmicb.2022.834927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/07/2022] [Indexed: 12/25/2022] Open
Abstract
Many viruses exploit thin projections of filopodia for cell entry and cell-to-cell spread. Using primary cultures of human iris stromal (HIS) cells derived from human eye donors, we report a significant increase in filopodia formation during human cytomegalovirus (HCMV) infection. Using confocal microscopy, we observed a large number of virions being frequently associated along the filopodia prior to cell infection. Depolymerization of actin filaments resulted in a significant inhibition of HCMV entry into HIS cell. Our results further revealed that the transient expression of HCMV envelope glycoprotein B (gB) triggers the induction of the filopodial system. Since gB is known to bind the diverse chains of heparan sulfate (HS), a comparative study was performed to evaluate the gB-mediated filopodial induction in cells expressing either wild-type HS and/or 3-O sulfated HS (3-OS HS). We found that cells co-expressing HCMV gB together with the 3-O sulfotranseferase-3 (3-OST-3) enzyme had a much higher and robust filopodia induction compared to cells co-expressing gB with wild-type HS. The above results were further verified by pre-treating HIS cells with anti-3-OS HS (G2) peptide and/or heparinase-I before challenging with HCMV infection, which resulted in a significant loss in the filopodial counts as well as decreased viral infectivity. Taken together, our findings highlight that HCMV entry into HIS cells actively modulates the actin cytoskeleton via coordinated actions possibly between gB and the 3-OS HS receptor to influence viral infectivity.
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Affiliation(s)
- Kenneth Chang
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Hardik Majmudar
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Ritesh Tandon
- Department of Microbiology and Immunology, University of Mississippi Medical Center, Jackson, MS, United States
| | - Michael V Volin
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
| | - Vaibhav Tiwari
- Department of Microbiology and Immunology, College of Graduate Studies, Chicago College of Osteopathic Medicine, and Chicago College of Pharmacy, Midwestern University, Downers Grove, IL, United States
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3
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Embedding of HIV Egress within Cortical F-Actin. Pathogens 2022; 11:pathogens11010056. [PMID: 35056004 PMCID: PMC8777837 DOI: 10.3390/pathogens11010056] [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: 11/12/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/07/2022] Open
Abstract
F-Actin remodeling is important for the spread of HIV via cell-cell contacts; however, the mechanisms by which HIV corrupts the actin cytoskeleton are poorly understood. Through live cell imaging and focused ion beam scanning electron microscopy (FIB-SEM), we observed F-Actin structures that exhibit strong positive curvature to be enriched for HIV buds. Virion proteomics, gene silencing, and viral mutagenesis supported a Cdc42-IQGAP1-Arp2/3 pathway as the primary intersection of HIV budding, membrane curvature and F-Actin regulation. Whilst HIV egress activated the Cdc42-Arp2/3 filopodial pathway, this came at the expense of cell-free viral release. Importantly, release could be rescued by cell-cell contact, provided Cdc42 and IQGAP1 were present. From these observations, we conclude that a proportion out-going HIV has corrupted a central F-Actin node that enables initial coupling of HIV buds to cortical F-Actin to place HIV at the leading cell edge. Whilst this initially prevents particle release, the maturation of cell-cell contacts signals back to this F-Actin node to enable viral release & subsequent infection of the contacting cell.
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4
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Delva JL, Van Waesberghe C, Klupp BG, Mettenleiter TC, Favoreel HW. Alphaherpesvirus-induced activation of plasmacytoid dendritic cells depends on the viral glycoprotein gD and is inhibited by non-infectious light particles. PLoS Pathog 2021; 17:e1010117. [PMID: 34843605 PMCID: PMC8659615 DOI: 10.1371/journal.ppat.1010117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/09/2021] [Accepted: 11/16/2021] [Indexed: 12/28/2022] Open
Abstract
Plasmacytoid dendritic cells (pDC) are important innate immune cells during the onset of viral infections as they are specialized in the production of massive amounts of antiviral type I interferon (IFN). Alphaherpesviruses such as herpes simplex virus (HSV) or pseudorabies virus (PRV) are double stranded DNA viruses and potent stimulators of pDC. Detailed information on how PRV activates porcine pDC is lacking. Using PRV and porcine primary pDC, we report here that PRV virions, so-called heavy (H-)particles, trigger IFNα production by pDC, whereas light (L-) particles that lack viral DNA and capsid do not. Activation of pDC requires endosomal acidification and, importantly, depends on the PRV gD envelope glycoprotein and O-glycosylations. Intriguingly, both for PRV and HSV-1, we found that L-particles suppress H-particle-mediated activation of pDC, a process which again depends on viral gD. This is the first report describing that gD plays a critical role in alphaherpesvirus-induced pDC activation and that L-particles directly interfere with alphaherpesvirus-induced IFNα production by pDC.
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Affiliation(s)
- Jonas L Delva
- Department of Virology, Parasitology, Immunology-Faculty of Veterinary Medicine-Ghent University, Merelbeke, Belgium
| | - Cliff Van Waesberghe
- Department of Virology, Parasitology, Immunology-Faculty of Veterinary Medicine-Ghent University, Merelbeke, Belgium
| | - Barbara G Klupp
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Thomas C Mettenleiter
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Herman W Favoreel
- Department of Virology, Parasitology, Immunology-Faculty of Veterinary Medicine-Ghent University, Merelbeke, Belgium
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Kennedy PGE, Mogensen TH, Cohrs RJ. Recent Issues in Varicella-Zoster Virus Latency. Viruses 2021; 13:v13102018. [PMID: 34696448 PMCID: PMC8540691 DOI: 10.3390/v13102018] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/30/2021] [Accepted: 10/02/2021] [Indexed: 12/16/2022] Open
Abstract
Varicella-zoster virus (VZV) is a human herpes virus which causes varicella (chicken pox) as a primary infection, and, following a variable period of latency in neurons in the peripheral ganglia, may reactivate to cause herpes zoster (shingles) as well as a variety of neurological syndromes. In this overview we consider some recent issues in alphaherpesvirus latency with special focus on VZV ganglionic latency. A key question is the nature and extent of viral gene transcription during viral latency. While it is known that this is highly restricted, it is only recently that the very high degree of that restriction has been clarified, with both VZV gene 63-encoded transcripts and discovery of a novel VZV transcript (VLT) that maps antisense to the viral transactivator gene 61. It has also emerged in recent years that there is significant epigenetic regulation of VZV gene transcription, and the mechanisms underlying this are complex and being unraveled. The last few years has also seen an increased interest in the immunological aspects of VZV latency and reactivation, in particular from the perspective of inborn errors of host immunity that predispose to different VZV reactivation syndromes.
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Affiliation(s)
- Peter G. E. Kennedy
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G61 1QH, UK
- Correspondence:
| | - Trine H. Mogensen
- Department of Infectious Diseases, Aarhus University Hospital, 8000 Aarhus, Denmark;
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Randall J. Cohrs
- Department of Neurology, University of Colorado School of Medicine, 80045 Aurora, CO, USA
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6
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Near-atomic cryo-electron microscopy structures of varicella-zoster virus capsids. Nat Microbiol 2020; 5:1542-1552. [PMID: 32895526 DOI: 10.1038/s41564-020-0785-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 08/03/2020] [Indexed: 12/18/2022]
Abstract
Varicella-zoster virus (VZV) is a medically important human herpesvirus that causes chickenpox and shingles, but its cell-associated nature has hindered structure studies. Here we report the cryo-electron microscopy structures of purified VZV A-capsid and C-capsid, as well as of the DNA-containing capsid inside the virion. Atomic models derived from these structures show that, despite enclosing a genome that is substantially smaller than those of other human herpesviruses, VZV has a similarly sized capsid, consisting of 955 major capsid protein (MCP), 900 small capsid protein (SCP), 640 triplex dimer (Tri2) and 320 triplex monomer (Tri1) subunits. The VZV capsid has high thermal stability, although with relatively fewer intra- and inter-capsid protein interactions and less stably associated tegument proteins compared with other human herpesviruses. Analysis with antibodies targeting the N and C termini of the VZV SCP indicates that the hexon-capping SCP-the largest among human herpesviruses-uses its N-terminal half to bridge hexon MCP subunits and possesses a C-terminal flexible half emanating from the inner rim of the upper hexon channel into the tegument layer. Correlation of these structural features and functional observations provide insights into VZV assembly and pathogenesis and should help efforts to engineer gene delivery and anticancer vectors based on the currently available VZV vaccine.
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Exocytosis of Progeny Infectious Varicella-Zoster Virus Particles via a Mannose-6-Phosphate Receptor Pathway without Xenophagy following Secondary Envelopment. J Virol 2020; 94:JVI.00800-20. [PMID: 32493818 PMCID: PMC7394889 DOI: 10.1128/jvi.00800-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 05/26/2020] [Indexed: 12/19/2022] Open
Abstract
The literature on the egress of different herpesviruses after secondary envelopment is contradictory. In this report, we investigated varicella-zoster virus (VZV) egress in a cell line from a child with Pompe disease, a glycogen storage disease caused by a defect in the enzyme required for glycogen digestion. In Pompe cells, both the late autophagy pathway and the mannose-6-phosphate receptor (M6PR) pathway are interrupted. We have postulated that intact autophagic flux is required for higher recoveries of VZV infectivity. To test that hypothesis, we infected Pompe cells and then assessed the VZV infectious cycle. We discovered that the infectious cycle in Pompe cells was remarkably different from that of either fibroblasts or melanoma cells. No large late endosomes filled with VZV particles were observed in Pompe cells; only individual viral particles in small vacuoles were seen. The distribution of the M6PR pathway (trans-Golgi network to late endosomes) was constrained in infected Pompe cells. When cells were analyzed with two different anti-M6PR antibodies, extensive colocalization of the major VZV glycoprotein gE (known to contain M6P residues) and the M6P receptor (M6PR) was documented in the viral highways at the surfaces of non-Pompe cells after maximum-intensity projection of confocal z-stacks, but neither gE nor the M6PR was seen in abundance at the surfaces of infected Pompe cells. Taken together, our results suggested that (i) Pompe cells lack a VZV trafficking pathway within M6PR-positive large endosomes and (ii) most infectious VZV particles in conventional cell substrates are transported via large M6PR-positive vacuoles without degradative xenophagy to the plasma membrane.IMPORTANCE The long-term goal of this research has been to determine why VZV, when grown in cultured cells, invariably is more cell associated and has a lower titer than other alphaherpesviruses, such as herpes simplex virus 1 (HSV1) or pseudorabies virus (PRV). Data from both HSV1 and PRV laboratories have identified a Rab6 secretory pathway for the transport of single enveloped viral particles from the trans-Golgi network within small vacuoles to the plasma membrane. In contrast, after secondary envelopment in fibroblasts or melanoma cells, multiple infectious VZV particles accumulated within large M6PR-positive late endosomes that were not degraded en route to the plasma membrane. We propose that this M6PR pathway is most utilized in VZV infection and least utilized in HSV1 infection, with PRV's usage being closer to HSV1's usage. Supportive data from other VZV, PRV, and HSV1 laboratories about evidence for two egress pathways are included.
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8
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Buckingham EM, Girsch J, Jackson W, Cohen JI, Grose C. Autophagy Quantification and STAT3 Expression in a Human Skin Organ Culture Model for Innate Immunity to Herpes Zoster. Front Microbiol 2018; 9:2935. [PMID: 30568636 PMCID: PMC6290052 DOI: 10.3389/fmicb.2018.02935] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 11/14/2018] [Indexed: 12/28/2022] Open
Abstract
The goal of this project was to document the autophagy response in human neonatal skin organ culture (SOC) after infection with varicella-zoster virus (VZV). The VZV-infected SOC model has attributes of herpes zoster, in that an injection of virus into the skin is analogous to exit of virus from the sensory nerve termini into skin during herpes zoster. Cultures were maintained for 28 days and periodically examined for an autophagy response by quantitation of autophagosomes with Imaris software. Expression of the STAT3 protein was plentiful in the VZV-infected SOC. Abundant autophagy was observed in VZV-infected SOC between 14 and 28 days after infection, while autophagy in mock-infected SOC was minimal (p = 0.0003). The autophagic response after infection of SOC with a recombinant VZV genome containing the herpes simplex virus ICP34.5 neurovirulence gene was similar to wild-type VZV (p = 0.3). These results suggested that the VZV-infected SOC system resembled biopsy data from herpes zoster infection of skin. An enhanced autophagy response has now been reported after infection with two additional alpha herpesviruses besides VZV, namely, pseudorabies virus and duck enteritis herpes virus; both lack the ICP34.5 protein.
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Affiliation(s)
- Erin M. Buckingham
- Virology Laboratory, Children’s Hospital, University of Iowa, Iowa City, IA, United States
| | - James Girsch
- Virology Laboratory, Children’s Hospital, University of Iowa, Iowa City, IA, United States
| | - Wallen Jackson
- Virology Laboratory, Children’s Hospital, University of Iowa, Iowa City, IA, United States
| | - Jeffrey I. Cohen
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Charles Grose
- Virology Laboratory, Children’s Hospital, University of Iowa, Iowa City, IA, United States
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Qualitative Differences in Capsidless L-Particles Released as a By-Product of Bovine Herpesvirus 1 and Herpes Simplex Virus 1 Infections. J Virol 2018; 92:JVI.01259-18. [PMID: 30185590 PMCID: PMC6206470 DOI: 10.1128/jvi.01259-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 08/23/2018] [Indexed: 01/25/2023] Open
Abstract
The alphaherpesvirus family includes viruses that infect humans and animals. Hence, not only do they have a significant impact on human health, but they also have a substantial economic impact on the farming industry. While the pathogenic manifestations of the individual viruses differ from host to host, their relative genetic compositions suggest similarity at the molecular level. This study provides a side-by-side comparison of the particle outputs from the major human pathogen HSV-1 and the veterinary pathogen BoHV-1. Ultrastructural and proteomic analyses have revealed that both viruses have broadly similar morphogenesis profiles and infectious virus compositions. However, the demonstration that BoHV-1 has the capacity to generate vast numbers of capsidless enveloped particles that differ from those produced by HSV-1 in composition implies a divergence in the cell biology of these viruses that impacts our general understanding of alphaherpesvirus morphogenesis. Despite differences in the pathogenesis and host range of alphaherpesviruses, many stages of their morphogenesis are thought to be conserved. Here, an ultrastructural study of bovine herpesvirus 1 (BoHV-1) envelopment revealed profiles similar to those previously found for herpes simplex virus 1 (HSV-1), with BoHV-1 capsids associating with endocytic tubules. Consistent with the similarity of their genomes and envelopment strategies, the proteomic compositions of BoHV-1 and HSV-1 virions were also comparable. However, BoHV-1 morphogenesis exhibited a diversity in envelopment events. First, heterogeneous primary envelopment profiles were readily detectable at the inner nuclear membrane of BoHV-1-infected cells. Second, the BoHV-1 progeny comprised not just full virions but also an abundance of capsidless, noninfectious light particles (L-particles) that were released from the infected cells in numbers similar to those of virions and in the absence of DNA replication. Proteomic analysis of BoHV-1 L-particles and the much less abundant HSV-1 L-particles revealed that they contained the same complement of envelope proteins as virions but showed variations in tegument content. In the case of HSV-1, the UL46 tegument protein was reproducibly found to be >6-fold enriched in HSV-1 L-particles. More strikingly, the tegument proteins UL36, UL37, UL21, and UL16 were depleted in BoHV-1 but not HSV-1 L-particles. We propose that these combined differences reflect the presence of truly segregated “inner” and “outer” teguments in BoHV-1, making it a critical system for studying the structure and process of tegumentation and envelopment. IMPORTANCE The alphaherpesvirus family includes viruses that infect humans and animals. Hence, not only do they have a significant impact on human health, but they also have a substantial economic impact on the farming industry. While the pathogenic manifestations of the individual viruses differ from host to host, their relative genetic compositions suggest similarity at the molecular level. This study provides a side-by-side comparison of the particle outputs from the major human pathogen HSV-1 and the veterinary pathogen BoHV-1. Ultrastructural and proteomic analyses have revealed that both viruses have broadly similar morphogenesis profiles and infectious virus compositions. However, the demonstration that BoHV-1 has the capacity to generate vast numbers of capsidless enveloped particles that differ from those produced by HSV-1 in composition implies a divergence in the cell biology of these viruses that impacts our general understanding of alphaherpesvirus morphogenesis.
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Bubak AN, Como CN, Blackmon AM, Frietze S, Mescher T, Jones D, Cohrs RJ, Paucek P, Baird NL, Nagel MA. Varicella Zoster Virus Induces Nuclear Translocation of the Neurokinin-1 Receptor, Promoting Lamellipodia Formation and Viral Spread in Spinal Astrocytes. J Infect Dis 2018; 218:1324-1335. [PMID: 29788447 PMCID: PMC6129113 DOI: 10.1093/infdis/jiy297] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/14/2018] [Indexed: 12/11/2022] Open
Abstract
Background Varicella zoster virus (VZV) can present as a myelopathy with spinal astrocyte infection. Recent studies support a role for the neurokinin-1 receptor (NK-1R) in virus infections, as well as for cytoskeletal alterations that may promote viral spread. Thus, we examined the role of NK-1R in VZV-infected primary human spinal astrocytes (HA-sps) to shed light on the pathogenesis of VZV myelopathy. Methods Mock- and VZV-infected HA-sps were examined for substance P (subP) production, NK-1R localization, morphological changes, and viral spread in the presence or absence of the NK-1R antagonists aprepitant and rolapitant. Results VZV infection of HA-sps induced nuclear localization of full-length and truncated NK-1R in the absence of the endogenous ligand, subP, and was associated with extensive lamellipodia formation and viral spread that was inhibited by NK-1R antagonists. Conclusions We have identified a novel, subP-independent, proviral function of nuclear NK-1R associated with lamellipodia formation and viral spread that is distinct from subP-induced NK-1R cell membrane/cytoplasmic localization without lamellipodia formation. These results suggest that binding of a putative viral ligand to NK-1R produces a dramatically different NK-1R downstream effect than binding of subP. Finally, the NK-1R antagonists aprepitant and rolapitant provide promising alternatives to nucleoside analogs in treating VZV infections, including myelopathy.
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Affiliation(s)
- Andrew N Bubak
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Christina N Como
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Anna M Blackmon
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Seth Frietze
- Department of Medical Laboratory and Radiation Sciences, University of Vermont, Burlington
| | - Teresa Mescher
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Dallas Jones
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Randall J Cohrs
- Department of Neurology, University of Colorado School of Medicine, Aurora
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora
| | - Petr Paucek
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Nicholas L Baird
- Department of Neurology, University of Colorado School of Medicine, Aurora
| | - Maria A Nagel
- Department of Neurology, University of Colorado School of Medicine, Aurora
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora
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11
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Jarosinski KW, Carpenter JE, Buckingham EM, Jackson W, Knudtson K, Moffat JF, Kita H, Grose C. Cellular Stress Response to Varicella-Zoster Virus Infection of Human Skin Includes Highly Elevated Interleukin-6 Expression. Open Forum Infect Dis 2018; 5:ofy118. [PMID: 30014002 DOI: 10.1093/ofid/ofy118] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/18/2018] [Indexed: 12/17/2022] Open
Abstract
Background The infectious cycle of varicella-zoster virus (VZV) after reactivation from the dorsal root ganglia includes replication and assembly of complete enveloped virions in the human skin to cause the characteristic herpes zoster (shingles). Methods To pursue studies of innate immunity to VZV infection, we have adapted a fetal skin organ culture model to a human neonatal foreskin explant model. Results Abundant expression of VZV IE62, gE, and gC was visualized by confocal microscopy while numerous enveloped virions were observed by electron microscopy in infected skin organ cultures. Microarray experiments demonstrated that the patterns of upregulated transcripts differed between VZV-infected cells and VZV-infected skin explants. One result stood out, namely a >30-fold elevated interleukin (IL)-6 level in the infected skin explant that was not present in the infected monolayer culture. The IL-6 results in the polyermase chain reaction (PCR) assay were reproduced by quantitative PCR testing with newly designed primers. To determine if increased transcription was accompanied by increased IL-6 expression, we quantitated the levels of IL-6 protein in the explant media at increasing intervals after infection. We found a statistically significant increase in IL-6 protein levels secreted into the media from VZV-infected skin explants as compared with mock-infected explants. Conclusions The cellular stress response to VZV infection in neonatal skin explants included highly elevated levels of IL-6 transcription and expression. This skin organ model could be adapted to other viruses with a skin tropism, such as herpes simplex virus.
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Affiliation(s)
| | - John E Carpenter
- Division of Infectious Diseases/Virology, University of Iowa, Iowa City, Iowa
| | - Erin M Buckingham
- Division of Infectious Diseases/Virology, University of Iowa, Iowa City, Iowa
| | - Wallen Jackson
- Division of Infectious Diseases/Virology, University of Iowa, Iowa City, Iowa
| | - Kevin Knudtson
- Iowa Institute of Human Genetics, University of Iowa, Iowa City, Iowa
| | - Jennifer F Moffat
- Department of Microbiology and Immunology, SUNY Upstate Medical University, Syracuse, New York
| | - Hirohito Kita
- Department of Immunology, Mayo Clinic, Rochester, Minnesota
| | - Charles Grose
- Division of Infectious Diseases/Virology, University of Iowa, Iowa City, Iowa
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Cytoskeletons in the Closet-Subversion in Alphaherpesvirus Infections. Viruses 2018; 10:v10020079. [PMID: 29438303 PMCID: PMC5850386 DOI: 10.3390/v10020079] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/30/2018] [Accepted: 02/07/2018] [Indexed: 12/14/2022] Open
Abstract
Actin filaments, microtubules and intermediate filaments form the cytoskeleton of vertebrate cells. Involved in maintaining cell integrity and structure, facilitating cargo and vesicle transport, remodelling surface structures and motility, the cytoskeleton is necessary for the successful life of a cell. Because of the broad range of functions these filaments are involved in, they are common targets for viral pathogens, including the alphaherpesviruses. Human-tropic alphaherpesviruses are prevalent pathogens carried by more than half of the world’s population; comprising herpes simplex virus (types 1 and 2) and varicella-zoster virus, these viruses are characterised by their ability to establish latency in sensory neurons. This review will discuss the known mechanisms involved in subversion of and transport via the cytoskeleton during alphaherpesvirus infections, focusing on protein-protein interactions and pathways that have recently been identified. Studies on related alphaherpesviruses whose primary host is not human, along with comparisons to more distantly related beta and gammaherpesviruses, are also presented in this review. The need to decipher as-yet-unknown mechanisms exploited by viruses to hijack cytoskeletal components—to reveal the hidden cytoskeletons in the closet—will also be addressed.
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Multiple Roles of the Cytoplasmic Domain of Herpes Simplex Virus 1 Envelope Glycoprotein D in Infected Cells. J Virol 2016; 90:10170-10181. [PMID: 27581980 DOI: 10.1128/jvi.01396-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/23/2016] [Indexed: 01/27/2023] Open
Abstract
Herpes simplex virus 1 (HSV-1) envelope glycoprotein D (gD) plays an essential role in viral entry. The functional regions of gD responsible for viral entry have been mapped to its extracellular domain, whereas the gD cytoplasmic domain plays no obvious role in viral entry. Thus far, the role(s) of the gD cytoplasmic domain in HSV-1 replication has remained to be elucidated. In this study, we show that ectopic expression of gD induces microvillus-like tubular structures at the plasma membrane which resemble the reported projection structures of the plasma membrane induced in HSV-1-infected cells. Mutations in the arginine cluster (residues 365 to 367) in the gD cytoplasmic domain greatly reduced gD-induced plasma membrane remodeling. In agreement with this, the mutations in the arginine cluster in the gD cytoplasmic domain reduced the number of microvillus-like tubular structures at the plasma membrane in HSV-1-infected cells. In addition, the mutations produced an accumulation of unenveloped nucleocapsids in the cytoplasm and reduced viral replication and cell-cell spread. These results suggest that the arginine cluster in the gD cytoplasmic domain is required for the efficient induction of plasma membrane projections and viral final envelopment, and these functions of the gD domain may lead to efficient viral replication and cell-cell spread. IMPORTANCE The cytoplasmic domain of HSV-1 gD, an envelope glycoprotein essential for viral entry, was reported to promote viral replication and cell-cell spread, but the role(s) of the domain during HSV-1 infection has remained unknown. In this study, we clarify two functions of the arginine cluster in the HSV-1 gD cytoplasmic domain, both of which require host cell membrane remodeling, i.e., the formation of microvillus-like projections at the plasma membrane and viral final envelopment in HSV-1-infected cells. We also show that the gD arginine cluster is required for efficient HSV-1 replication and cell-cell spread. This is the first report clarifying not only the functions of the gD cytoplasmic domain but also identifying the gD arginine cluster to be the HSV-1 factor responsible for the induction of plasma membrane projections in HSV-1-infected cells. Our results elucidate some of the functions of this multifunctional envelope glycoprotein during HSV-1 infection.
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Exocytosis of Varicella-Zoster Virus Virions Involves a Convergence of Endosomal and Autophagy Pathways. J Virol 2016; 90:8673-85. [PMID: 27440906 PMCID: PMC5021422 DOI: 10.1128/jvi.00915-16] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/13/2016] [Indexed: 02/06/2023] Open
Abstract
UNLABELLED Varicella-zoster virus (VZV) is an extremely cell-associated herpesvirus with limited egress of viral particles. The induction of autophagy in VZV-infected monolayers is easily detectable; inhibition of autophagy leads to decreased VZV glycoprotein biosynthesis and diminished viral titers. To explain how autophagic flux could exert a proviral effect on the VZV infectious cycle, we postulated that the VZV exocytosis pathway following secondary envelopment may converge with the autophagy pathway. This hypothesis depended on known similarities between VZV gE and autophagy-related (Atg) Atg9/Atg16L1 trafficking pathways. Investigations were carried out with highly purified fractions of VZV virions. When the virion fraction was tested for the presence of autophagy and endosomal proteins, microtubule-associated protein 1 light chain (MAP1LC3B) and Ras-like GTPase 11 (Rab11) were detected. By two-dimensional (2D) and 3D imaging after immunolabeling, both proteins also colocalized with VZV gE in a proportion of cytoplasmic vesicles. When purified VZV virions were enumerated after immunoelectron microscopy, gold beads were detected on viruses following incubation with antibodies to VZV gE (∼100%), Rab11 (50%), and LC3B (30%). Examination of numerous electron micrographs demonstrated that enveloped virions were housed in single-membraned vesicles; viral particles were not observed in autophagosomes. Taken together, our data suggested that some viral particles after secondary envelopment accumulated in a heterogeneous population of single-membraned vesicular compartments, which were decorated with components from both the endocytic pathway (Rab11) and the autophagy pathway (LC3B). The latter cytoplasmic viral vesicles resembled an amphisome. IMPORTANCE VZV infection leads to increased autophagic flux, while inhibition of autophagy leads to a marked reduction in virus spread. In this investigation of the proviral role of autophagy, we found evidence for an intersection of viral exocytosis and autophagy pathways. Specifically, both LC3-II and Rab11 proteins copurified with some infectious VZV particles. The results suggested that a subpopulation of VZV particles were carried to the cell surface in single-walled vesicles with attributes of an amphisome, an organelle formed from the fusion of an endosome and an autophagosome. Our results also addressed the interpretation of autophagy/xenophagy results with mutated herpes simplex virus lacking its ICP34.5 neurovirulence gene (HSVΔ34.5). The VZV genome lacks an ICP34.5 ortholog, yet we found no evidence of VZV particles housed in a double-membraned autophagosome. In other words, xenophagy, a degradative process documented after infection with HSVΔ34.5, was not observed in VZV-infected cells.
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Szulc-Dabrowska L, Gregorczyk KP, Struzik J, Boratynska-Jasinska A, Szczepanowska J, Wyzewski Z, Toka FN, Gierynska M, Ostrowska A, Niemialtowski MG. Remodeling of the fibroblast cytoskeletal architecture during the replication cycle of Ectromelia virus: A morphological in vitro study in a murine cell line. Cytoskeleton (Hoboken) 2016; 73:396-417. [DOI: 10.1002/cm.21308] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 05/07/2016] [Accepted: 05/10/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Lidia Szulc-Dabrowska
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
| | - Karolina P. Gregorczyk
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
| | - Justyna Struzik
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
| | - Anna Boratynska-Jasinska
- Molecular Biology Unit, Mossakowski Medical Research Centre, Polish Academy of Sciences; Warsaw Poland
| | - Joanna Szczepanowska
- Laboratory of Bioenergetics and Biomembranes, Department of Biochemistry; Nencki Institute of Experimental Biology; Warsaw Poland
| | - Zbigniew Wyzewski
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
| | - Felix N. Toka
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
- Department of Biomedical Sciences; Ross University School of Veterinary Medicine; St. Kitts West Indies
| | - Malgorzata Gierynska
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
| | | | - Marek G. Niemialtowski
- Division of Immunology, Department of Preclinical Sciences, Faculty of Veterinary Medicine; Warsaw University of Life Sciences-SGGW; Warsaw Poland
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16
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Chang K, Baginski J, Hassan SF, Volin M, Shukla D, Tiwari V. Filopodia and Viruses: An Analysis of Membrane Processes in Entry Mechanisms. Front Microbiol 2016; 7:300. [PMID: 27014223 PMCID: PMC4785137 DOI: 10.3389/fmicb.2016.00300] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022] Open
Abstract
Filopodia are thin, actin rich bundles protruding from cell plasma membranes, serving physiological purposes, such as probing the environment and facilitating cell-to-cell adhesion. Recent studies have highlighted that actively polymerized filopodial-protrusions are exploited during virus entry, trafficking, spread, and the development of clinical pathology of viral diseases. These observations have caused a surge in investigation of the key determinants of filopodial induction and their influence on cell topography including receptor expression for viral entry. It is now very clear that filopodia can provide unique opportunities for many viruses to invade host cells vertically during primary infection, or horizontally during virus spread from cell-to-cell. These emerging concepts can explain the unprecedented ability of viruses to invade both nearby and long-distant host cells, a feature that may directly contribute to viral tropism. In this review, we summarize the significance of filopodia in viral diseases and discuss future therapeutic possibilities to precisely target filopodial-flyovers to prevent or control infectious diseases.
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Affiliation(s)
- Kenneth Chang
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - John Baginski
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - Samer F Hassan
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago Chicago, IL, USA
| | - Michael Volin
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
| | - Deepak Shukla
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago Chicago, IL, USA
| | - Vaibhav Tiwari
- Department of Microbiology and Immunology, Chicago College of Osteopathic Medicine, Midwestern University Downers Grove, IL, USA
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17
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Ouwendijk WJD, Verjans GMGM. Pathogenesis of varicelloviruses in primates. J Pathol 2015; 235:298-311. [PMID: 25255989 DOI: 10.1002/path.4451] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 09/19/2014] [Accepted: 09/22/2014] [Indexed: 01/01/2023]
Abstract
Varicelloviruses in primates comprise the prototypic human varicella-zoster virus (VZV) and its non-human primate homologue, simian varicella virus (SVV). Both viruses cause varicella as a primary infection, establish latency in ganglionic neurons and reactivate later in life to cause herpes zoster in their respective hosts. VZV is endemic worldwide and, although varicella is usually a benign disease in childhood, VZV reactivation is a significant cause of neurological disease in the elderly and in immunocompromised individuals. The pathogenesis of VZV infection remains ill-defined, mostly due to the species restriction of VZV that impedes studies in experimental animal models. SVV infection of non-human primates parallels virological, clinical, pathological and immunological features of human VZV infection, thereby providing an excellent model to study the pathogenesis of varicella and herpes zoster in its natural host. In this review, we discuss recent studies that provided novel insight in both the virus and host factors involved in the three elementary stages of Varicellovirus infection in primates: primary infection, latency and reactivation.
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18
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Taylor MP, Enquist LW. Axonal spread of neuroinvasive viral infections. Trends Microbiol 2015; 23:283-8. [PMID: 25639651 DOI: 10.1016/j.tim.2015.01.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/31/2014] [Accepted: 01/07/2015] [Indexed: 02/05/2023]
Abstract
Neuroinvasive viral infections invade the nervous system, often eliciting serious disease and death. Members of four viral families are both neuroinvasive and capable of transmitting progeny virions or virion components within the long neuronal extensions known as axons. Axons provide physical structures that enable viral infection to spread within the host while avoiding extracellular immune responses. Technological advances in the analysis of in vivo neural circuits, neuronal culturing, and live imaging of fluorescent fusion proteins have enabled an unprecedented view into the steps of virion assembly, transport, and egress involved in axonal spread. In this review we summarize the literature supporting anterograde (axon to cell) spread of viral infection, describe the various strategies of virion transport, and discuss the effects of spread on populations of neuroinvasive viruses.
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Affiliation(s)
- Matthew P Taylor
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59718, USA.
| | - Lynn W Enquist
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA; Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
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19
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Carpenter JE, Grose C. Varicella-zoster virus glycoprotein expression differentially induces the unfolded protein response in infected cells. Front Microbiol 2014; 5:322. [PMID: 25071735 PMCID: PMC4076746 DOI: 10.3389/fmicb.2014.00322] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 06/11/2014] [Indexed: 02/03/2023] Open
Abstract
Varicella-zoster virus (VZV) is a human herpesvirus that spreads to children as varicella or chicken pox. The virus then establishes latency in the nervous system and re-emerges, typically decades later, as zoster or shingles. We have reported previously that VZV induces autophagy in infected cells as well as exhibiting evidence of the Unfolded Protein Response (UPR): XBP1 splicing, a greatly expanded Endoplasmic Reticulum (ER) and CHOP expression. Herein we report the results of a UPR specific PCR array that measures the levels of mRNA of 84 different components of the UPR in VZV infected cells as compared to tunicamycin treated cells as a positive control and uninfected, untreated cells as a negative control. Tunicamycin is a mixture of chemicals that inhibits N-linked glycosylation in the ER with resultant protein misfolding and the UPR. We found that VZV differentially induces the UPR when compared to tunicamycin treatment. For example, tunicamycin treatment moderately increased (8-fold) roughly half of the array elements while downregulating only three (one ERAD and two FOLD components). VZV infection on the other hand upregulated 33 components including a little described stress sensor CREB-H (64-fold) as well as ER membrane components INSIG and gp78, which modulate cholesterol synthesis while downregulating over 20 components mostly associated with ERAD and FOLD. We hypothesize that this expression pattern is associated with an expanding ER with downregulation of active degradation by ERAD and apoptosis as the cell attempts to handle abundant viral glycoprotein synthesis.
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Affiliation(s)
- John E Carpenter
- Virology Laboratory, Department of Infectious Diseases, University of Iowa Children's Hospital Iowa City, IA, USA
| | - Charles Grose
- Virology Laboratory, Department of Infectious Diseases, University of Iowa Children's Hospital Iowa City, IA, USA
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20
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Kobiler O, Drayman N, Butin-Israeli V, Oppenheim A. Virus strategies for passing the nuclear envelope barrier. Nucleus 2012; 3:526-39. [PMID: 22929056 PMCID: PMC3515536 DOI: 10.4161/nucl.21979] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Viruses that replicate in the nucleus need to pass the nuclear envelope barrier during infection. Research in recent years indicates that the nuclear envelope is a major hurdle for many viruses. This review describes strategies to overcome this obstacle developed by seven virus families: herpesviridae, adenoviridae, orthomyxoviridae, lentiviruses (which are part of retroviridae), Hepadnaviridae, parvoviridae and polyomaviridae. Most viruses use the canonical nuclear pore complex (NPC) in order to get their genome into the nucleus. Viral capsids that are larger than the nuclear pore disassemble before or during passing through the NPC, thus allowing genome nuclear entry. Surprisingly, increasing evidence suggest that parvoviruses and polyomaviruses may bypass the nuclear pore by trafficking directly through the nuclear membrane. Additional studies are required for better understanding these processes. Since nuclear entry emerges as the limiting step in infection for many viruses, it may serve as an ideal target for antiviral drug development.
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Affiliation(s)
- Oren Kobiler
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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21
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The attenuated genotype of varicella-zoster virus includes an ORF0 transitional stop codon mutation. J Virol 2012; 86:10695-703. [PMID: 22837206 DOI: 10.1128/jvi.01067-12] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Varicella-zoster virus (VZV) is the first of the human herpesviruses to be attenuated and subsequently approved as a live vaccine to prevent varicella and herpes zoster. Both the attenuated VZV vaccine, called vaccine Oka or vOka, and the parental strain pOka have been completely sequenced. Yet the specific determinants of attenuation are uncertain. The open reading frame (ORF) with the most single nucleotide polymorphisms (SNPs), ORF62, encodes the regulatory protein IE62, but IE62 studies have failed to define a specific SNP associated with attenuation. We have completed next-generation sequencing of the VZV Ellen genome, a strain known to be highly attenuated by its very limited replication in human skin xenografts in the SCID mouse model of VZV pathogenesis. A comparative analysis of the Ellen sequence with all other complete VZV sequences was extremely informative. In particular, an unexpected finding was a stop codon mutation in Ellen ORF0 (herpes simplex virus UL56 homolog) identical to one found in vOka, combined with the absence of polymorphisms in most Ellen ORFs that were known to be mutated in vOka. The mutated ORF0 protein was also imaged in both two dimensions and three dimensions by confocal microscopy. The probability of two VZV strains not connected by a recent common ancestor having an identical ORF0 SNP by chance would be 1 × 10(-8), in other words, extremely unlikely. Taken together, these bioinformatics analyses strongly suggest that the stop codon ORF0 SNP is one of the determinants of the attenuation genotype of live VZV vaccines.
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22
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Autophagosome formation during varicella-zoster virus infection following endoplasmic reticulum stress and the unfolded protein response. J Virol 2011; 85:9414-24. [PMID: 21752906 DOI: 10.1128/jvi.00281-11] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Autophagy is a recently recognized component of the life cycle of varicella-zoster virus (VZV). We have documented abundant autophagosome formation in skin vesicles (final site of virion assembly) from randomly selected cases of varicella and zoster. The fact that autophagy was an early event in the VZV replication cycle was documented by finding infected vesicle cells with the VZV IE62 protein confined to the nucleus. Next, we pursued studies in VZV-infected cultured cells to define whether autophagy was preceded by endoplasmic reticulum (ER) stress and the unfolded protein response (UPR). First, we demonstrated that autophagosome formation in infected cells closely resembled that seen after treatment of cells with tunicamycin, a potent initiator of ER stress. Second, we demonstrated a marked expansion of ER size in both VZV-infected cells and cells transfected with the predominant VZV glycoprotein complex gE/gI. An enlarged ER is critical evidence of ER stress, which in turn is relieved by the UPR. To this end, we documented the UPR by detecting the alternatively spliced form of the XBP1 protein as well as CHOP (C/EBP homologous protein), both transcriptional activators of other UPR genes in an ER stress-dependent manner. Because VZV does not encode inhibitors of autophagy, the above results suggested that autophagy was a common event in VZV-infected cells and that it was provoked at least in part by ER stress secondary to overly abundant VZV glycoprotein biosynthesis, which led to UPR activation in an attempt to maintain cellular homeostasis.
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23
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Grose C, Carpenter JE, Jackson W, Duus KM. Overview of varicella-zoster virus glycoproteins gC, gH and gL. Curr Top Microbiol Immunol 2010; 342:113-28. [PMID: 20186613 DOI: 10.1007/82_2009_4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The VZV genome is smaller than the HSV genome and only encodes nine glycoproteins. This chapter provides an overview of three VZV glycoproteins: gH (ORF37), gL (ORF60), and gC (ORF14). All three glycoproteins are highly conserved among the alpha herpesviruses. However, VZV gC exhibits unexpected differences from its HSV counterpart gC. In particular, both VZV gC transcription and protein expression are markedly delayed in cultured cells. These delays occur regardless of the virus strain or the cell type, and may account in part for the aberrant assembly of VZV particles. In contrast to VZV gC, the general properties of gH and gL more closely resemble their HSV homologs. VZV gL behaves as a chaperone protein to facilitate the maturation of the gH protein. The mature gH protein in turn is a potent fusogen. Its fusogenic activity can be abrogated when infected cultures are treated with monoclonal anti-gH antibodies.
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Affiliation(s)
- Charles Grose
- Department of Pediatrics/2501 JCP, University of Iowa Hospital, Iowa City, IA 52242, USA.
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24
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Brzozowska A, Rychłowski M, Lipińska AD, Bieńkowska-Szewczyk K. Point mutations in BHV-1 Us3 gene abolish its ability to induce cytoskeletal changes in various cell types. Vet Microbiol 2010; 143:8-13. [PMID: 20197221 DOI: 10.1016/j.vetmic.2010.02.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The Us3 gene is conserved among alphaherpesviruses and codes for a protein kinase, a multifunctional protein involved in many phases of virus infection, like nuclear egress, modulation of apoptosis and modification of the cellular cytoskeleton. Bovine herpesvirus (BHV-1), a member of the Alphaherpesvirinae, contains an open reading frame homologous to Us3 of other herpesviruses, which has been identified as a serine/threonine kinase (Takashima, Y., Tamura, H., Xuan, X., Otsuka, H., 1999. Identification of the Us3 gene product of BHV-1 as a protein kinase and characterization of BHV-1 mutants of the Us3 gene. Virus Res. 59, 23-34). To study the activity of BHV-1 Us3, we have cloned its sequence under control of the human cytomegalovirus (HCMV) promoter/enhancer and introduced it into a recombinant baculovirus (Bac Us3). Confocal microscopy analysis showed profound cytoskeletal modifications in various BHV-1-permissive and non-permissive cells transduced with BacUs3. We observed that Us3 expression changed cellular shape and induced formation of long microtubule-containing cell projections, a phenomenon which had also been observed in cells expressing pseudorabies virus Us3. The intracellular localization of Us3 was mostly nuclear but when the protein accumulated it could be detected in the cytoplasm, cell membranes and projections. Mutated forms of BHV-1 Us3 with point mutations near or within the kinase catalytic domain did not affect cell morphology indicating that kinase activity of BHV-1 Us3 is required for its cytoskeleton remodelling function.
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Affiliation(s)
- Agnieszka Brzozowska
- Department of Molecular Virology, Faculty of Biotechnology, University of Gdańsk, Kladki 24, 80-822 Gdańsk, Poland
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Abstract
Two major structural elements of a cell are the cytoskeleton and the lipid membranes. Actin and cholesterol are key components of the cytoskeleton and membranes, respectively, and are involved in a plethora of different cellular processes. This review summarizes and discusses the interaction of alphaherpesviruses with actin and cholesterol during different stages of the replication cycle: virus entry, replication and assembly in the nucleus, and virus egress. Elucidating these interactions not only yields novel insights into the biology of these important pathogens, but may also shed new light on cell biological aspects of actin and cholesterol, and lead to novel avenues in the design of antiviral strategies.
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26
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Curanovic D, Enquist L. Directional transneuronal spread of α-herpesvirus infection. Future Virol 2009; 4:591. [PMID: 20161665 DOI: 10.2217/fvl.09.62] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Most α-herpesviruses are pantropic, neuroinvasive pathogens that establish a reactivateable, latent infection in the PNS of their natural hosts. Various manifestations of herpes disease rely on extent and direction of the spread of infection between the surface epithelia and the nervous system components that innervate that surface. One aspect of such controlled spread of infection is the capacity for synaptically defined, transneuronal spread, a property that makes α-herpesviruses useful tools for determining the connectivity of neural circuits. The current understanding of intra-axonal transport and transneuronal spread of α-herpesviruses is reviewed, focusing on work with herpes simplex virus and pseudorabies virus, the available in vitro technology used to study viral transport and spread is evaluated and how certain viral mutants can be used to examine neural circuit architecture is described in this article.
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Affiliation(s)
- D Curanovic
- Department of Pharmacology, Weill Medical College, Cornell University, New York, NY 10065, USA
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27
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Carpenter JE, Henderson EP, Grose C. Enumeration of an extremely high particle-to-PFU ratio for Varicella-zoster virus. J Virol 2009; 83:6917-21. [PMID: 19369328 PMCID: PMC2698559 DOI: 10.1128/jvi.00081-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Accepted: 04/09/2009] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) is renowned for its low titers. Yet investigations to explore the low infectivity are hampered by the fact that the VZV particle-to-PFU ratio has never been determined with precision. Herein, we accomplish that task by applying newer imaging technology. More than 300 images were taken of VZV-infected cells on 4 different samples at high magnification. We enumerated the total number of viral particles within 25 cm(2) of the infected monolayer at 415 million. Based on these numbers, the VZV particle:PFU ratio was approximately 40,000:1 for a cell-free inoculum.
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Affiliation(s)
- John E Carpenter
- Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa 52242, USA
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28
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Alphaherpesvirus US3-mediated reorganization of the actin cytoskeleton is mediated by group A p21-activated kinases. Proc Natl Acad Sci U S A 2009; 106:8707-12. [PMID: 19435845 DOI: 10.1073/pnas.0900436106] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The US3 protein is a viral serine/threonine kinase that is conserved among all members of the Alphaherpesvirinae. The US3 protein of different alphaherpesviruses causes dramatic alterations in the actin cytoskeleton, such as the disassembly of actin stress fibers and formation of cell projections, which have been associated with increased intercellular virus spread. Here, we find that inhibiting group A p21-activated kinases (PAKs), which are key regulators in Cdc42/Rac1 Rho GTPase signaling pathways, impairs US3-mediated actin alterations. By using PAK1(-/-) and PAK2(-/-) mouse embryo fibroblasts (MEFs), we show that US3-mediated stress fiber disassembly requires PAK2, whereas US3-mediated cell projection formation mainly is mediated by PAK1, also indicating that PAK1 and PAK2 can have different biological effects on the organization of the actin cytoskeleton. In addition, US3 was found to bind and phosphorylate group A PAKs. Lack of group A PAKs in MEFs was correlated with inefficient virus spread. Thus, US3 induces its effect on the actin cytoskeleton via group A PAKs.
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Varicella-zoster virus infection induces autophagy in both cultured cells and human skin vesicles. J Virol 2009; 83:5466-76. [PMID: 19297471 DOI: 10.1128/jvi.02670-08] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
When grown in cultured cells, varicella-zoster virus (VZV) forms many aberrant light particles and produces low titers. Various studies have explored the reasons for such a phenotype and have pointed to impaired expression of specific late genes and at lysosomal targeting of egressing virions as possible causes. In the studies presented here, we report that the autophagic degradation pathway was induced at late time points after VZV infection of cultured cells, as documented by immunoblot analysis of the cellular proteins LC3B and p62/SQSTM1, along with electron microscopy analysis, which demonstrated the presence of both early autophagosomes and late autophagic compartments. Autophagy was induced in infected cells even in the presence of phosphonoacetic acid, an inhibitor of viral late gene expression, thus suggesting that accumulation of immediate-early and early viral gene products might be the major stimulus for its induction. We also showed that the autophagic response was not dependent on a specific cell substrate, virus strain, or type of inoculum. Finally, using immunofluorescence imaging, we demonstrated autophagosome-specific staining in human zoster vesicles but not in normal skin. Thus, our results document that this innate immune response pathway is a component of the VZV infectious cycle in both cultured cells and the human skin vesicle, the final site of virion formation in the infected human host.
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He S, Zhang D, Cheng F, Gong F, Guo Y. Applications of RNA interference in cancer therapeutics as a powerful tool for suppressing gene expression. Mol Biol Rep 2009; 36:2153-63. [PMID: 19117119 DOI: 10.1007/s11033-008-9429-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2008] [Accepted: 12/08/2008] [Indexed: 01/07/2023]
Abstract
Cancer poses a tremendous therapeutic challenge worldwide, highlighting the critical need for developing novel therapeutics. A promising cancer treatment modality is gene therapy, which is a form of molecular medicine designed to introduce into target cells genetic material with therapeutic intent. The history of RNA interference (RNAi) has only a dozen years, however, further studies have revealed that it is a potent method of gene silencing that has developed rapidly over the past few years as a result of its extensive importance in the study of genetics, molecular biology and physiology. RNAi is a natural process by which small interfering RNA (siRNA) duplex directs sequence specific post-transcriptional silencing of homologous genes by binding to its complementary mRNA and triggering its elimination. RNAi has been extensively used as a novel and effective gene silencing tool for the fundamental research of cancer therapeutics, and has displayed great potential in clinical treatment.
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Affiliation(s)
- Song He
- Molecular Medicine & Tumor Research Center, Chongqing Medical University, Chongqing, China.
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Storlie J, Carpenter JE, Jackson W, Grose C. Discordant varicella-zoster virus glycoprotein C expression and localization between cultured cells and human skin vesicles. Virology 2008; 382:171-81. [PMID: 18954885 DOI: 10.1016/j.virol.2008.09.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Revised: 09/23/2008] [Accepted: 09/24/2008] [Indexed: 11/26/2022]
Abstract
Because of its very low titer, varicella-zoster virus (VZV) infectivity is usually transferred by passage of trypsin dispersed infected cells. Previously, we observed that gC biosynthesis was markedly delayed in monolayers inoculated with cell free virus. In this report, we investigated the kinetics of gC expression in more detail and included studies of monolayers inoculated with trypsin dispersed infected cells, the more traditional method of VZV infection. Extensive imaging analyses disclosed that gC was detectable in some inoculum cells, but little gC biosynthesis occurred during the first 48 hpi in the newly infected underlying monolayer. In contrast, during the first 24-48 hpi, expression of VZV gE and gB was easily detectable. Using real-time RT-PCR, we found a delay in accumulation of VZV gC transcripts that paralleled the delay in expression of VZV gC protein. Treatment with hexamethylene bisacetamide (HMBA) increased expression of both gC protein and gC mRNA. HMBA treatment also increased virus titer by 4-fold, but paradoxically reduced plaque size in the titration assay. Finally, we examined skin vesicles from cases of chickenpox and zoster in humans and observed abundant amounts of gC expression. In short, this report documents an unexpected delay in both gC mRNA and protein production under all conditions of VZV infection of cultured cells.
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Affiliation(s)
- Johnathan Storlie
- Departments of Microbiology and Pediatrics, University of Iowa, Iowa City, IA 52242, USA
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Deletion of the first cysteine-rich region of the varicella-zoster virus glycoprotein E ectodomain abolishes the gE and gI interaction and differentially affects cell-cell spread and viral entry. J Virol 2008; 83:228-40. [PMID: 18945783 DOI: 10.1128/jvi.00913-08] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Varicella-zoster virus (VZV) glycoprotein E (gE) is the most abundant glycoprotein in infected cells and, in contrast to those of other alphaherpesviruses, is essential for viral replication. The gE ectodomain contains a unique N-terminal region required for viral replication, cell-cell spread, and secondary envelopment; this region also binds to the insulin-degrading enzyme (IDE), a proposed VZV receptor. To identify new functional domains of the gE ectodomain, the effect of mutagenesis of the first cysteine-rich region of the gE ectodomain (amino acids 208 to 236) was assessed using VZV cosmids. Deletion of this region was compatible with VZV replication in vitro, but cell-cell spread of the rOka-DeltaCys mutant was reduced significantly. Deletion of the cysteine-rich region abolished the binding of the mutant gE to gI but not to IDE. Preventing gE binding to gI altered the pattern of gE expression at the plasma membrane of infected cells and the posttranslational maturation of gI and its incorporation into viral particles. In contrast, deletion of the first cysteine-rich region did not affect viral entry into human tonsil T cells in vitro or into melanoma cells infected with cell-free VZV. These experiments demonstrate that gE/gI heterodimer formation is essential for efficient cell-cell spread and incorporation of gI into viral particles but that it is dispensable for infectious varicella-zoster virion formation and entry into target cells. Blocking gE binding to gI resulted in severe impairment of VZV infection of human skin xenografts in SCIDhu mice in vivo, documenting the importance of cell fusion mediated by this complex for VZV virulence in skin.
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