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Rapchak K, Yagobian SD, Moore J, Khattri M, Shuda M. Merkel cell polyomavirus small T antigen is a viral transcription activator that is essential for viral genome maintenance. PLoS Pathog 2022; 18:e1011039. [PMID: 36574443 PMCID: PMC9829177 DOI: 10.1371/journal.ppat.1011039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 01/09/2023] [Accepted: 12/01/2022] [Indexed: 12/29/2022] Open
Abstract
Merkel cell polyomavirus (MCV) is a small DNA tumor virus that persists in human skin and causes Merkel cell carcinoma (MCC) in immunocompromised individuals. The multi-functional protein MCV small T (sT) activates viral DNA replication by stabilizing large T (LT) and promotes cell transformation through the LT stabilization domain (LTSD). Using MCVΔsT, a mutant MCV clone that ablates sT, we investigated the role of sT in MCV genome maintenance. sT was dispensable for initiation of viral DNA replication, but essential for maintenance of the MCV genome and activation of viral early and late gene expression for progression of the viral lifecycle. Furthermore, in phenotype rescue studies, exogenous sT activated viral DNA replication and mRNA expression in MCVΔsT through the LTSD. While exogenous LT expression, which mimics LT stabilization, increased viral DNA replication, it did not activate viral mRNA expression. After cataloging transcriptional regulator proteins by proximity-based MCV sT-host protein interaction analysis, we validated LTSD-dependent sT interaction with four transcriptional regulators: Cux1, c-Jun, BRD9, and CBP. Functional studies revealed Cux1 and c-Jun as negative regulators, and CBP and BRD9 as positive regulators of MCV transcription. CBP inhibitor A-485 suppressed sT-induced viral gene activation in replicating MCVΔsT and inhibited early gene expression in MCV-integrated MCC cells. These results suggest that sT promotes viral lifecycle progression by activating mRNA expression and capsid protein production through interaction with the transcriptional regulators. This activity is essential for MCV genome maintenance, suggesting a critical role of sT in MCV persistence and MCC carcinogenesis.
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Affiliation(s)
- Kyle Rapchak
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Shiva D. Yagobian
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Jackson Moore
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Michelle Khattri
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
| | - Masahiro Shuda
- Cancer Virology Program, University of Pittsburgh Medical Center (UPMC) Hillman Cancer Center, Pittsburgh, Pennsylvania, United States of America
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Moscoso CG, Steer CJ. The Evolution of Gene Therapy in the Treatment of Metabolic Liver Diseases. Genes (Basel) 2020; 11:genes11080915. [PMID: 32785089 PMCID: PMC7463482 DOI: 10.3390/genes11080915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/02/2020] [Accepted: 08/06/2020] [Indexed: 12/12/2022] Open
Abstract
Monogenic metabolic disorders of hepatic origin number in the hundreds, and for many, liver transplantation remains the only cure. Liver-targeted gene therapy is an attractive treatment modality for many of these conditions, and there have been significant advances at both the preclinical and clinical stages. Viral vectors, including retroviruses, lentiviruses, adenovirus-based vectors, adeno-associated viruses and simian virus 40, have differing safety, efficacy and immunogenic profiles, and several of these have been used in clinical trials with variable success. In this review, we profile viral vectors and non-viral vectors, together with various payloads, including emerging therapies based on RNA, that are entering clinical trials. Genome editing technologies are explored, from earlier to more recent novel approaches that are more efficient, specific and safe in reaching their target sites. The various curative approaches for the multitude of monogenic hepatic metabolic disorders currently at the clinical development stage portend a favorable outlook for this class of genetic disorders.
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Affiliation(s)
- Carlos G. Moscoso
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Correspondence: (C.G.M.); (C.J.S.); Tel.: +1-612-625-8999 (C.G.M. & C.J.S.); Fax: +1-612-625-5620 (C.G.M. & C.J.S.)
| | - Clifford J. Steer
- Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Department of Genetics, Cell Biology and Development, University of Minnesota Medical School, Minneapolis, MN 55455, USA
- Correspondence: (C.G.M.); (C.J.S.); Tel.: +1-612-625-8999 (C.G.M. & C.J.S.); Fax: +1-612-625-5620 (C.G.M. & C.J.S.)
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Generation of a Vero-Based Packaging Cell Line to Produce SV40 Gene Delivery Vectors for Use in Clinical Gene Therapy Studies. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 6:124-134. [PMID: 28791314 PMCID: PMC5537168 DOI: 10.1016/j.omtm.2017.06.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 06/30/2017] [Indexed: 02/07/2023]
Abstract
Replication-defective (RD) recombinant simian virus 40 (SV40)-based gene delivery vectors hold a great potential for clinical applications because of their presumed non-immunogenicity and capacity to induce immune tolerance to the transgene products in humans. However, the clinical use of SV40 vectors has been hampered by the lack of a packaging cell line that produces replication-competent (RC) free SV40 particles in the vector production process. To solve this problem, we have adapted the current SV40 vector genome used for the production of vector particles and generated a novel Vero-based packaging cell line named SuperVero that exclusively expresses the SV40 large T antigen. SuperVero cells produce similar numbers of SV40 vector particles compared to the currently used packaging cell lines, albeit in the absence of contaminating RC SV40 particles. Our unique SV40 vector platform named SVac paves the way to clinically test a whole new generation of SV40-based therapeutics for a broad range of important diseases.
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Delbue S, Comar M, Ferrante P. Review on the role of the human Polyomavirus JC in the development of tumors. Infect Agent Cancer 2017; 12:10. [PMID: 28174598 PMCID: PMC5292005 DOI: 10.1186/s13027-017-0122-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/24/2017] [Indexed: 12/12/2022] Open
Abstract
Almost one fifth of human cancers worldwide are associated with infectious agents, either bacteria or viruses, and this makes the possible association between infections and tumors a relevant research issue. We focused our attention on the human Polyomavirus JC (JCPyV), that is a small, naked DNA virus, belonging to the Polyomaviridae family. It is the recognized etiological agent of the Progressive Multifocal Leukoencephalopathy (PML), a fatal demyelinating disease, occurring in immunosuppressed individuals. JCPyV is able to induce cell transformation in vitro when infecting non-permissive cells, that do not support viral replication and JCPyV inoculation into small animal models and non human primates drives to tumor formation. The molecular mechanisms involved in JCPyV oncogenesis have been extensively studied: the main oncogenic viral protein is the large tumor antigen (T-Ag), that is able to bind, among other cellular factors, both Retinoblastoma protein (pRb) and p53 and to dysregulate the cell cycle, but also the early proteins small tumor antigen (t-Ag) and Agnoprotein appear to cooperate in the process of cell transformation. Consequently, it is not surprising that JCPyV genomic sequences and protein expression have been detected in Central Nervous System (CNS) tumors and colon cancer and an association between this virus and several brain and non CNS-tumors has been proposed. However, the significances of these findings are under debate because there is still insufficient evidence of a casual association between JCPyV and solid cancer development. In this paper we summarized and critically analyzed the published literature, in order to describe the current knowledge on the possible role of JCPyV in the development of human tumors.
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Affiliation(s)
- Serena Delbue
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Via Pascal, 36-20133 Milan, Italy
| | - Manola Comar
- Department of Medical Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health-IRCCS "Burlo Garofolo", 34137 Trieste, Italy
| | - Pasquale Ferrante
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Via Pascal, 36-20133 Milan, Italy.,Istituto Clinico Città Studi, Milan, Italy
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Haugg AM, Rennspiess D, Hausen AZ, Speel EJM, Cathomas G, Becker JC, Schrama D. Fluorescencein situhybridization and qPCR to detect Merkel cell polyomavirus physical status and load in Merkel cell carcinomas. Int J Cancer 2014; 135:2804-15. [DOI: 10.1002/ijc.28931] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 04/09/2014] [Indexed: 01/25/2023]
Affiliation(s)
- Anke M. Haugg
- Department of Pathology; GROW-School for Oncology and Developmental Biology, Maastricht UMC; Maastricht The Netherlands
| | - Dorit Rennspiess
- Department of Pathology; GROW-School for Oncology and Developmental Biology, Maastricht UMC; Maastricht The Netherlands
| | - Axel zur Hausen
- Department of Pathology; GROW-School for Oncology and Developmental Biology, Maastricht UMC; Maastricht The Netherlands
| | - Ernst-Jan M. Speel
- Department of Pathology; GROW-School for Oncology and Developmental Biology, Maastricht UMC; Maastricht The Netherlands
| | | | - Jürgen C. Becker
- Department of Dermatology; Division of General Dermatology; Medical University of Graz; Graz Austria
| | - David Schrama
- Department of Dermatology; Division of General Dermatology; Medical University of Graz; Graz Austria
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Symens N, Soenen SJ, Rejman J, Braeckmans K, De Smedt SC, Remaut K. Intracellular partitioning of cell organelles and extraneous nanoparticles during mitosis. Adv Drug Deliv Rev 2012; 64:78-94. [PMID: 22210278 DOI: 10.1016/j.addr.2011.11.012] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 11/21/2011] [Accepted: 11/23/2011] [Indexed: 02/06/2023]
Abstract
The nucleocytoplasmic partitioning of nanoparticles as a result of cell division is highly relevant to the field of nonviral gene delivery. We reviewed the literature on the intracellular distribution of cell organelles (the endosomal vesicles, Golgi apparatus, endoplasmic reticulum and nucleus), foreign macromolecules (dextrans and plasmid DNA) and inorganic nanoparticles (gold, quantum dot and iron oxide) during mitosis. For nonviral gene delivery particles (lipid- or polymer-based), indirect proof of nuclear entry during mitosis is provided. We also describe how retroviruses and latent DNA viruses take advantage of mitosis to transfer their viral genome and segregate their episomes into the host daughter nuclei. Based on this knowledge, we propose strategies to improve nonviral gene delivery in dividing cells with the ultimate goal of designing nonviral gene delivery systems that are as efficient as their viral counterparts but non-immunogenic, non-oncogenic and easy and inexpensive to prepare.
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Affiliation(s)
- Nathalie Symens
- Laboratory of General Biochemistry and Physical Pharmacy, Ghent Research Group on Nanomedicines, Ghent University, Ghent, Belgium.
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Zhang L, Qi F, Gaudino G, Strianese O, Yang H, Morris P, Pass HI, Nerurkar VR, Bocchetta M, Carbone M. Tissue Tropism of SV40 Transformation of Human Cells: Role of the Viral Regulatory Region and of Cellular Oncogenes. Genes Cancer 2011; 1:1008-20. [PMID: 21779427 DOI: 10.1177/1947601910395580] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 11/21/2010] [Accepted: 11/29/2010] [Indexed: 11/17/2022] Open
Abstract
SV40 has been detected prevalently in a limited panel of human tumors: mesothelioma, bone and brain tumors, and lymphoma. These are the same tumor types that are specifically induced by SV40 when injected into hamsters, a finding that has raised concerns about the possible pathogenic role of SV40 in humans. Two different SV40 isolates differing in the number of 72-bp elements in the virus regulatory region, archetypal SV40 (1ESV40), which contains one 72 bp, and nonarchetypal SV40 (wtSV40), which contains two 72 bp, have been detected in human tumors. 1ESV40 has been prevalently detected in brain tumors, with wtSV40 prevalently in mesothelioma. The apparent different cell tropism could be related to the virus (i.e., possibly to the number of 72-bp elements) and to different expression of cellular genes, known to play a critical role in SV40-mediated transformation of human cells, such as Notch-1 and c-Met. To test for possible differences in tissue tropism, we infected primary human mesothelial cells (HM) and primary human astrocytes (Ast) with 1ESV40 and with wtSV40 from 2 different SV40 strains, 776 and Baylor. All viruses transformed astrocytes; only wtSV40 transformed HM. Intracellular signaling of c-Met and Notch-1 was differently induced by these 2 viruses in HM and Ast. Differences in Notch-1 expression and signaling (i.e., downstream effectors, c-Myc, HEY-1, HES-1, and HEY-L) appeared to influence SV40-mediated transformation of primary astrocytes and mesothelial cells. Our results provide a biological rationale to the observation that 1ESV40 is prevalently detected in brain tumors and wtSV40 in mesotheliomas.
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Affiliation(s)
- Lei Zhang
- University of Hawai'i Cancer Center, Honolulu, HI, USA
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Bollag B, Hofstetter CA, Reviriego-Mendoza MM, Frisque RJ. JC virus small T antigen binds phosphatase PP2A and Rb family proteins and is required for efficient viral DNA replication activity. PLoS One 2010; 5:e10606. [PMID: 20485545 PMCID: PMC2868895 DOI: 10.1371/journal.pone.0010606] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 04/19/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The human polyomavirus, JC virus (JCV) produces five tumor proteins encoded by transcripts alternatively spliced from one precursor messenger RNA. Significant attention has been given to replication and transforming activities of JCV's large tumor antigen (TAg) and three T' proteins, but little is known about small tumor antigen (tAg) functions. Amino-terminal sequences of tAg overlap with those of the other tumor proteins, but the carboxy half of tAg is unique. These latter sequences are the least conserved among the early coding regions of primate polyomaviruses. METHODOLOGY AND FINDINGS We investigated the ability of wild type and mutant forms of JCV tAg to interact with cellular proteins involved in regulating cell proliferation and survival. The JCV P99A tAg is mutated at a conserved proline, which in the SV40 tAg is required for efficient interaction with protein phosphatase 2A (PP2A), and the C157A mutant tAg is altered at one of two newly recognized LxCxE motifs. Relative to wild type and C157A tAgs, P99A tAg interacts inefficiently with PP2A in vivo. Unlike SV40 tAg, JCV tAg binds to the Rb family of tumor suppressor proteins. Viral DNAs expressing mutant t proteins replicated less efficiently than did the intact JCV genome. A JCV construct incapable of expressing tAg was replication-incompetent, a defect not complemented in trans using a tAg-expressing vector. CONCLUSIONS JCV tAg possesses unique properties among the polyomavirus small t proteins. It contributes significantly to viral DNA replication in vivo; a tAg null mutant failed to display detectable DNA replication activity, and a tAg substitution mutant, reduced in PP2A binding, was replication-defective. Our observation that JCV tAg binds Rb proteins, indicates all five JCV tumor proteins have the potential to influence cell cycle progression in infected and transformed cells. It remains unclear how these proteins coordinate their unique and overlapping functions.
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Affiliation(s)
- Brigitte Bollag
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Catherine A. Hofstetter
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Marta M. Reviriego-Mendoza
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Richard J. Frisque
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
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Swanson PA, Lukacher AE, Szomolanyi-Tsuda E. Immunity to polyomavirus infection: the polyomavirus-mouse model. Semin Cancer Biol 2009; 19:244-51. [PMID: 19505652 DOI: 10.1016/j.semcancer.2009.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 02/01/2009] [Accepted: 02/06/2009] [Indexed: 11/28/2022]
Abstract
A ubiquitous clinically silent murine pathogen, polyomavirus has enjoyed long-term co-evolution with the mouse, a highly tractable and genetically and immunologically informative small animal model. Thus, polyomavirus has provided a valuable experimental construct to decipher the host immune mechanisms that come into play to control systemic low-level persistent viral infections. Impaired immunosurveillance for infected cells puts the murine host at risk both to injury resulting from excessive direct virus cytolysis and development of virus-induced tumors. In this review, we present our current understanding of the multifaceted immune response invoked by the mouse to maintain détente with this potentially deleterious persistent natural pathogen, and discuss implications of these studies for therapeutic interventions for human polyomavirus infection.
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Affiliation(s)
- Phillip A Swanson
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322, USA
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Carbone M, Pannuti A, Zhang L, Testa JR, Bocchetta M. A novel mechanism of late gene silencing drives SV40 transformation of human mesothelial cells. Cancer Res 2008; 68:9488-96. [PMID: 19010924 DOI: 10.1158/0008-5472.can-08-2332] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Suppression of the late gene expression, usually by integration of the viral DNA into the host genome, is a critical step in DNA tumor virus carcinogenesis. SV40 induces high rates of transformation in infected primary human mesothelial cells in tissue culture, leading to the formation of immortal cell lines (SV40-transformed human mesothelial cell lines, S-HML). The studies described here were designed to elucidate the unusual susceptibility of primary human mesothelial cells to SV40 carcinogenesis. We found that S-HML contained wild-type, mostly episomal SV40 DNA. In these cells, the early genes that code for the viral oncogenes are expressed; at the same time, the synthesis of the late genes, capsid proteins, is suppressed and S-HML are not lysed. Late gene suppression is achieved through the production of antisense RNA molecules. These antisense RNA molecules originate in the early region of the SV40 circular chromosome and proceed in antisense orientation into the late gene region, leading to the formation of highly unstable double-strand RNA, which is rapidly degraded. Our results reveal a novel biological mechanism responsible for the suppression of late viral gene products, an important step in viral carcinogenesis in humans.
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Affiliation(s)
- Michele Carbone
- Thoracic Oncology Program, Cancer Center of Hawaii and Department of Pathology, University of Hawaii Medical School, Honolulu, Hawaii 96813, USA.
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Association of simian virus 40 vp1 with 70-kilodalton heat shock proteins and viral tumor antigens. J Virol 2008; 83:37-46. [PMID: 18945763 DOI: 10.1128/jvi.00844-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Proper folding of newly synthesized viral proteins in the cytoplasm is a prerequisite for the formation of infectious virions. The major capsid protein Vp1 of simian virus 40 forms a series of disulfide-linked intermediates during folding and capsid formation. In addition, we report here that Vp1 is associated with cellular chaperones (HSP70) and a cochaperone (Hsp40) which can be coimmunoprecipitated with Vp1. Studies in vitro demonstrated the ATP-dependent interaction of Vp1 and cellular chaperones. Interestingly, viral cochaperones LT and ST were essential for stable interaction of HSP70 with the core Vp1 pentamer Vp1 (22-303). LT and ST also coimmunoprecipitated with Vp1 in vivo. In addition to these identified (co)chaperones, stable, covalently modified forms of Vp1 were identified for a folding-defective double mutant, C49A-C87A, and may represent a "trapped" assembly intermediate. By a truncation of the carboxyl arm of Vp1 to prevent the Vp1 folding from proceeding beyond pentamers, we detected several apparently modified Vp1 species, some of which were absent in cells transfected with the folding-defective mutant DNA. These results suggest that transient covalent interactions with known or unknown cellular and viral proteins are important in the assembly process.
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Katzman RB, Seeger M, Rundell K. SV40 reporter viruses. J Virol Methods 2008; 150:7-13. [PMID: 18403028 DOI: 10.1016/j.jviromet.2008.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 02/12/2008] [Accepted: 02/18/2008] [Indexed: 10/22/2022]
Abstract
Three simian virus 40 (SV40) reporter viruses were constructed in this study. One expresses the green fluorescent protein (GFP) as a fusion protein with the first exon of large-T (LT) antigen and is useful for live-cell imaging. A second reporter virus has a FLAG epitope tag at the C-terminus of large-T antigen (vC-LT(FLAG)), and a third has the FLAG tag at the N-terminus of LT (vN-LT(FLAG)). The vC-LT(FLAG) construct grows to titers near those of wild-type (WT) virus and functions well as a reporter virus for SV40 infection. The vN-LT(FLAG) construct, while viable, has a defect in the production and spread of infectious particles. All three viruses are useful in detecting superinfecting virus in cells in which nuclear LT is already present, such as persistently infected human mesothelial cells.
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Affiliation(s)
- Rebecca B Katzman
- Department of Microbiology-Immunology and The Robert H. Lurie Comprehensive Cancer Center, Northwestern University, 303 E. Chicago Avenue, Chicago, IL 60611, USA.
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