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Majerciak V, Alvarado-Hernandez B, Ma Y, Duduskar S, Lobanov A, Cam M, Zheng ZM. KSHV promotes oncogenic FOS to inhibit nuclease AEN and transactivate RGS2 for AKT phosphorylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.27.577582. [PMID: 38410462 PMCID: PMC10896338 DOI: 10.1101/2024.01.27.577582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) ORF57 is a lytic RNA-binding protein. We applied BCBL-1 cells in lytic KSHV infection and performed UV cross-linking immunoprecipitation (CLIP) followed by RNA-seq of the CLIPed RNA fragments (CLIP-seq). We identified ORF57-bound transcripts from 544 host protein-coding genes. By comparing with the RNA-seq profiles from BCBL-1 cells with latent and lytic KSHV infection and from HEK293T cells with and without ORF57 expression, we identified FOS and CITED2 RNAs being two common ORF57-specific RNA targets. FOS dimerizes with JUN as a transcription factor AP-1 involved in cell proliferation, differentiation, and transformation. Knockout of the ORF57 gene from the KSHV genome led BAC16-iSLK cells incapable of FOS expression in KSHV lytic infection. The dysfunctional KSHV genome in FOS expression could be rescued by Lenti-ORF57 virus infection. ORF57 protein does not regulate FOS translation but binds to the 13-nt RNA motif near the FOS RNA 5' end and prolongs FOS mRNA half-life 7.7 times longer than it is in the absence of ORF57. This binding of ORF57 to FOS RNA is competitive to the binding of a host nuclease AEN (also referred to as ISG20L1). KSHV infection inhibits the expression of AEN, but not exosomal RNA helicase MTR4. FOS expression mediated by ORF57 inhibits AEN transcription, but transactivates RGS2, a regulator of G-protein coupled receptors. FOS binds a conserved AP-1 site in the RGS2 promoter and enhances RGS2 expression to phosphorylate AKT. Altogether, we have discovered that KSHV ORF57 specifically binds and stabilizes FOS RNA to increase FOS expression, thereby disturbing host gene expression and inducing pathogenesis during KSHV lytic infection.
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Affiliation(s)
- Vladimir Majerciak
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, NCI/NIH, Frederick, MD, 21702, USA
| | - Beatriz Alvarado-Hernandez
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, NCI/NIH, Frederick, MD, 21702, USA
| | - Yanping Ma
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, NCI/NIH, Frederick, MD, 21702, USA
| | - Shivalee Duduskar
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, NCI/NIH, Frederick, MD, 21702, USA
| | - Alexei Lobanov
- CCR Collaborative Bioinformatics Resource, Center for Cancer Research, NCI/NIH, Bethesda, MD, 20892, USA
| | - Maggie Cam
- CCR Collaborative Bioinformatics Resource, Center for Cancer Research, NCI/NIH, Bethesda, MD, 20892, USA
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, NCI/NIH, Frederick, MD, 21702, USA
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Han L, Haefner V, Yu Y, Han B, Ren H, Irmler M, Beckers J, Liu Q, Feuchtinger A, Yildirim AO, Adler H, Stoeger T. Nanoparticle-Exposure-Triggered Virus Reactivation Induces Lung Emphysema in Mice. ACS NANO 2023; 17:21056-21072. [PMID: 37856828 PMCID: PMC10655245 DOI: 10.1021/acsnano.3c04111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 10/21/2023]
Abstract
Nanoparticles (NPs) released from engineered materials or combustion processes as well as persistent herpesvirus infection are omnipresent and are associated with chronic lung diseases. Previously, we showed that pulmonary exposure of a single dose of soot-like carbonaceous NPs (CNPs) or fiber-shaped double-walled carbon nanotubes (DWCNTs) induced an increase of lytic virus protein expression in mouse lungs latently infected with murine γ-herpesvirus 68 (MHV-68), with a similar pattern to acute infection suggesting virus reactivation. Here we investigate the effects of a more relevant repeated NP exposure on lung disease development as well as herpesvirus reactivation mechanistically and suggest an avenue for therapeutic prevention. In the MHV-68 mouse model, progressive lung inflammation and emphysema-like injury were detected 1 week after repetitive CNP and DWCNT exposure. NPs reactivated the latent herpesvirus mainly in CD11b+ macrophages in the lungs. In vitro, in persistently MHV-68 infected bone marrow-derived macrophages, ERK1/2, JNK, and p38 MAPK were rapidly activated after CNP and DWCNT exposure, followed by viral gene expression and increased viral titer but without generating a pro-inflammatory signature. Pharmacological inhibition of p38 activation abrogated CNP- but not DWCNT-triggered virus reactivation in vitro, and inhibitor pretreatment of latently infected mice attenuated CNP-exposure-induced pulmonary MHV-68 reactivation. Our findings suggest a crucial contribution of particle-exposure-triggered herpesvirus reactivation for nanomaterial exposure or air pollution related lung emphysema development, and pharmacological p38 inhibition might serve as a protective target to alleviate air pollution related chronic lung disease exacerbations. Because of the required precondition of latent infection described here, the use of single hit models might have severe limitations when assessing the respiratory toxicity of nanoparticle exposure.
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Affiliation(s)
- Lianyong Han
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Verena Haefner
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Youjia Yu
- Department
of Forensic Medicine, Nanjing Medical University, 211166 Nanjing, Jiangsu, China
| | - Bing Han
- Laboratory
of Translational Research “Stress and Immunity”, Department
of Anesthesiology, LMU Hospital, Ludwig-Maximilians-University
Munich, 81377 Munich, Germany
| | - Hongyu Ren
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Martin Irmler
- Institute
of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Johannes Beckers
- Institute
of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
- German Center
for Diabetes Research (DZD), 85764 Neuherberg, Germany
- Technische
Universität München, Chair
of Experimental Genetics, 80539 Munich, Germany
| | - Qiongliang Liu
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Annette Feuchtinger
- Research
Unit Analytical Pathology, Helmholtz Zentrum
München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
| | - Ali Oender Yildirim
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Institute
of Experimental Pneumology, University Hospital, Ludwig-Maximilians University, 81377 Munich, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Heiko Adler
- Institute
of Asthma and Allergy Prevention, Helmholtz
Zentrum München, German Research Center for Environmental Health, 85764 Neuherberg, Germany
- Walther Straub
Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University Munich, 80336 Munich, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
| | - Tobias Stoeger
- Institute
of Lung Health and Immunity (LHI), Comprehensive Pneumology Center, Helmholtz Zentrum München, German Research
Center for Environmental Health, 85764 Neuherberg, Germany
- Member
of the German Center of Lung Research (DZL), 81377 Munich, Germany
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3
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Lari A, Glaunsinger BA. Murine Gammaherpesvirus 68 ORF45 Stimulates B2 Retrotransposon and Pre-tRNA Activation in a Manner Dependent on Mitogen-Activated Protein Kinase (MAPK) Signaling. Microbiol Spectr 2023; 11:e0017223. [PMID: 36752632 PMCID: PMC10100704 DOI: 10.1128/spectrum.00172-23] [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: 01/13/2023] [Accepted: 01/21/2023] [Indexed: 02/09/2023] Open
Abstract
RNA polymerase III (RNAPIII) transcribes a variety of noncoding RNAs, including tRNA (tRNA) and the B2 family of short interspersed nuclear elements (SINEs). B2 SINEs are noncoding retrotransposons that possess tRNA-like promoters and are normally silenced in healthy somatic tissue. Infection with the murine gammaherpesvirus MHV68 induces transcription of both SINEs and tRNAs, in part through the activity of the viral protein kinase ORF36. Here, we identify the conserved MHV68 tegument protein ORF45 as an additional activator of these RNAPIII loci. MHV68 ORF45 and ORF36 form a complex, resulting in an additive induction RNAPIII and increased ORF45 expression. ORF45-induced RNAPIII transcription is dependent on its activation of the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway, which in turn increases the abundance of the RNAPIII transcription factor Brf1. Other viral and nonviral activators of MAPK/ERK signaling also increase the levels of Brf1 protein, B2 SINE RNA, and tRNA, suggesting that this is a common strategy to increase RNAPIII activity. IMPORTANCE Gammaherpesviral infection alters the gene expression landscape of a host cell, including through the induction of noncoding RNAs transcribed by RNA polymerase III (RNAPIII). Among these are a class of repetitive genes known as retrotransposons, which are normally silenced elements and can copy and spread throughout the genome, and transfer RNAs (tRNAs), which are fundamental components of protein translation machinery. How these loci are activated during infection is not well understood. Here, we identify ORF45 from the model murine gammaherpesvirus MHV68 as a novel activator of RNAPIII transcription. To do so, it engages the MAPK/ERK signaling pathway, which is a central regulator of cellular response to environmental stimuli. Activation of this pathway leads to the upregulation of a key factor required for RNAPIII activity, Brf1. These findings expand our understanding of the regulation and dysregulation of RNAPIII transcription and highlight how viral cooption of key signaling pathways can impact host gene expression.
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Affiliation(s)
- Azra Lari
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Britt A. Glaunsinger
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA
- Howard Hughes Medical Institute, Berkeley, California, USA
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Kang SK, Lee MJ, Ryu HH, Lee J, Lee MS. Dimethyl Sulfoxide Enhances Kaposi’s Sarcoma-Associated Herpesvirus Production During Lytic Replication. Front Microbiol 2021; 12:778525. [PMID: 34975802 PMCID: PMC8716793 DOI: 10.3389/fmicb.2021.778525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 11/19/2021] [Indexed: 02/05/2023] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is an etiologic agent of Kaposi’s sarcoma, primary effusion lymphoma, and multicentric Castleman disease. In studies of KSHV, efficient virus production and isolation are essential. Reactivation of KSHV can be initiated by treating latently infected cells with chemicals, such as 12-O-tetradecanoyl-phorbol-13-acetate and sodium butyrate. These chemicals have been used as tools to induce lytic replication and viral production in KSHV-producing cell lines. Dimethyl sulfoxide (DMSO) is an organosulfur compound that is frequently used as an aprotic solvent similar to water. In experiments exploring signaling pathways in KSHV-infected cells, DMSO treatment alone as a vehicle affected the lytic gene expression of KSHV. However, to the best of our knowledge, the effects of DMSO on KSHV-producing cells have not yet been reported. Therefore, in this study, we investigated whether DMSO could be used as a reagent to enhance viral production during lytic replication in KSHV-producing cells and assessed the underlying mechanisms. The effects of DMSO on KSHV production were analyzed in iSLK BAC16 cells, which have been widely used for recombinant KSHV production. We found that the production of KSHV virions was significantly increased by treatment with DMSO during the induction of lytic replication. Mechanistically, lytic genes of KSHV were enhanced by DMSO treatment, which was correlated with virion production. Additionally, DMSO induced the phosphorylation of JNK during lytic replication, and inhibition of JNK abolished the effects of DMSO on lytic replication and virion production. Our findings showed that additional treatment with DMSO during the induction of lytic replication significantly improved the yield of KSHV production.
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Affiliation(s)
- Su-Kyung Kang
- Department of Microbiology and Immunology, Eulji University School of Medicine, Daejeon, South Korea
| | - Myung-Ju Lee
- Department of Microbiology and Immunology, Eulji University School of Medicine, Daejeon, South Korea
| | - Ho-Hyun Ryu
- Department of Microbiology and Immunology, Eulji University School of Medicine, Daejeon, South Korea
| | - Jisu Lee
- Department of Microbiology and Immunology, Eulji University School of Medicine, Daejeon, South Korea
| | - Myung-Shin Lee
- Department of Microbiology and Immunology, Eulji University School of Medicine, Daejeon, South Korea
- Eulji Biomedical Science Research Institute, Eulji University School of Medicine, Daejeon, South Korea
- *Correspondence: Myung-Shin Lee,
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Naimo E, Zischke J, Schulz TF. Recent Advances in Developing Treatments of Kaposi's Sarcoma Herpesvirus-Related Diseases. Viruses 2021; 13:1797. [PMID: 34578378 PMCID: PMC8473310 DOI: 10.3390/v13091797] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/30/2021] [Accepted: 09/01/2021] [Indexed: 12/27/2022] Open
Abstract
Kaposi-sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) is the causative agent of several malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman's disease (MCD). Active KSHV replication has also been associated with a pathological condition called KSHV inflammatory cytokine syndrome (KICS), and KSHV may play a role in rare cases of post-transplant polyclonal lymphoproliferative disorders. Several commonly used herpesviral DNA polymerase inhibitors are active against KSHV in tissue culture. Unfortunately, they are not always efficacious against KSHV-induced diseases. To improve the outcome for the patients, new therapeutics need to be developed, including treatment strategies that target either viral proteins or cellular pathways involved in tumor growth and/or supporting the viral life cycle. In this review, we summarize the most commonly established treatments against KSHV-related diseases and review recent developments and promising new compounds that are currently under investigation or on the way to clinical use.
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Affiliation(s)
- Eleonora Naimo
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; (E.N.); (J.Z.)
- German Centre for Infection Research, Hannover-Braunschweig Site, 38023 Braunschweig, Germany
| | - Jasmin Zischke
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; (E.N.); (J.Z.)
- German Centre for Infection Research, Hannover-Braunschweig Site, 38023 Braunschweig, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; (E.N.); (J.Z.)
- German Centre for Infection Research, Hannover-Braunschweig Site, 38023 Braunschweig, Germany
- Cluster of Excellence 2155 RESIST, Institute of Virology, Hannover Medical School, 30625 Hannover, Germany
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6
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The Roles of c-Jun N-Terminal Kinase (JNK) in Infectious Diseases. Int J Mol Sci 2021; 22:ijms22179640. [PMID: 34502556 PMCID: PMC8431791 DOI: 10.3390/ijms22179640] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/03/2021] [Accepted: 09/03/2021] [Indexed: 01/12/2023] Open
Abstract
c-Jun N-terminal kinases (JNKs) are among the most crucial mitogen-activated protein kinases (MAPKs) and regulate various cellular processes, including cell proliferation, apoptosis, autophagy, and inflammation. Microbes heavily rely on cellular signaling pathways for their effective replication; hence, JNKs may play important roles in infectious diseases. In this review, we describe the basic signaling properties of MAPKs and JNKs in apoptosis, autophagy, and inflammasome activation. Furthermore, we discuss the roles of JNKs in various infectious diseases induced by viruses, bacteria, fungi, and parasites, as well as their potential to serve as targets for the development of therapeutic agents for infectious diseases. We expect this review to expand our understanding of the JNK signaling pathway’s role in infectious diseases and provide important clues for the prevention and treatment of infectious diseases.
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Markazi A, Meng W, Bracci PM, McGrath MS, Gao SJ. The Role of Bacteria in KSHV Infection and KSHV-Induced Cancers. Cancers (Basel) 2021; 13:cancers13174269. [PMID: 34503079 PMCID: PMC8428360 DOI: 10.3390/cancers13174269] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/05/2021] [Accepted: 08/19/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The aim of this article is to review the complex interactions of bacteria with Kaposi’s sarcoma-associated herpesvirus (KSHV) infection and KSHV-induced cancers. KSHV is causally associated with multiple cancers including Kaposi’s sarcoma (KS) and primary effusion lymphoma. Among patients coinfected by HIV and KSHV, patients with KS have a distinct oral microbiome compared to patients without KS. Moreover, KSHV patients have increased levels of salivary bacterial pathogen-associated molecular patterns compared to KSHV-negative patients. KSHV-associated bacterial species can increase KSHV replication and dissemination, and enhance cell proliferation of KSHV-transformed cells. The analysis of bacterial biomarkers associated with KSHV may help improve our understanding of the mechanisms driving KSHV-induced oncogenesis and identify novel targets for improving therapies of KSHV-related cancers. Abstract The objective of this article is to review the current status of the bacteria-virus interplay in Kaposi’s sarcoma-associated herpesvirus (KSHV) infection and KSHV-driven cancers. KSHV is the etiological agent of several cancers, including Kaposi’s sarcoma (KS) and primary effusion lymphoma. Due to immunosuppression, patients with KSHV are at an increased risk for bacterial infections. Moreover, among patients coinfected by HIV and KSHV, patients with KS have distinct oral microbiota compared to non-KS patients. Bacterial biomarkers associated with KSHV-driven cancers can provide insights in discerning the mechanisms of KSHV-induced oncogenesis. For example, pathogen-associated molecular patterns and bacterial products of certain bacterial species can regulate the expression of KSHV lytic and latent genes, thereby affecting viral replication and dissemination. In addition, infection with distinct opportunistic bacterial species have been associated with increased cell proliferation and tumorigenesis in KSHV-induced cancers through activation of pro-survival and -mitogenic cell signaling pathways. By elucidating the various mechanisms in which bacteria affect KSHV-associated pathogenesis, we will be able to pinpoint therapeutic targets for KSHV infection and KSHV-related cancers.
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Affiliation(s)
- Ashley Markazi
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, PA 15213, USA; (A.M.); (W.M.)
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Wen Meng
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, PA 15213, USA; (A.M.); (W.M.)
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
| | - Paige M. Bracci
- Department of Epidemiology and Biostatistics, University of California at San Francisco, San Francisco, CA 94158, USA;
| | - Michael S. McGrath
- Department of Laboratory Medicine, Pathology and Medicine, University of California at San Francisco, San Francisco, CA 94143, USA;
| | - Shou-Jiang Gao
- Cancer Virology Program, UPMC Hillman Cancer Center, Pittsburgh, PA 15213, USA; (A.M.); (W.M.)
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA
- Correspondence:
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HMGB1 Knockout Decreases Kaposi's Sarcoma-Associated Herpesvirus Virion Production in iSLK BAC16 Cells by Attenuating Viral Gene Expression. J Virol 2021; 95:e0079921. [PMID: 34105998 DOI: 10.1128/jvi.00799-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Multiple host proteins affect the gene expression of Kaposi's sarcoma-associated herpesvirus (KSHV) during latent and lytic replication. High-mobility group box 1 (HMGB1) serves as a highly conserved chromosomal protein inside the cell and a prototypical damage-associated molecular pattern molecule outside the cell. HMGB1 has been shown to play a pathogenic role in viral infectious diseases and to regulate the lytic replication of KSHV. However, its functional effects on the KSHV life cycle in KSHV-infected cells have not been fully elucidated. Here, we explored the role of intracellular and extracellular HMGB1 in KSHV virion production by employing CRISPR/Cas9-mediated HMGB1 knockout in the KSHV-producing iSLK BAC16 cell line. Intracellular HMGB1 formed complexes with various proteins, and the abundance of HMGB1-interacting proteins changed during latent and lytic replication. Moreover, extracellular HMGB1 was found to enhance lytic replication by phosphorylating JNK. Of note, the expression of viral genes was attenuated during lytic replication in HMGB1 knockout iSLK BAC16 cells, with significantly decreased production of infectious virions compared to that of wild-type cells. Collectively, our results demonstrate that HMGB1 is an important cellular cofactor that affects the generation of infectious KSHV progeny during lytic replication. IMPORTANCE The high-mobility group box 1 (HMGB1) protein has many intra- and extracellular biological functions with an intricate role in various diseases. In certain viral infections, HMGB1 affects the viral life cycle and pathogenesis. In this study, we explored the effects of HMGB1 knockout on the production of Kaposi's sarcoma-associated herpesvirus (KSHV). HMGB1 knockout decreased virion production in KSHV-producing cells by decreasing the expression of viral genes. The processes by which HMGB1 affects KSHV production may occur inside or outside infected cells. For instance, several cellular and viral proteins interacted with intracellular HMGB1 in a nucleosomal complex, whereas extracellular HMGB1 induced JNK phosphorylation, thereby enhancing lytic replication. Our results suggest that both intracellular and extracellular HMGB1 are necessary for efficient KSHV replication. Thus, HMGB1 may represent an effective therapeutic target for the regulation of KSHV production.
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9
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Jeon JH, Lee C. Stress-activated protein kinases are involved in the replication of porcine deltacoronavirus. Virology 2021; 559:196-209. [PMID: 33964685 DOI: 10.1016/j.virol.2021.04.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 11/30/2022]
Abstract
This study was conducted to examine the role of stress-activated protein kinases (SAPKs), including c-Jun NH2-terminal kinases (JNK1/2) and p38 mitogen-activated protein kinase (MAPK), in porcine deltacoronavirus (PDCoV) infection. Results demonstrated the activation of JNK1/2 and p38 MAPK in PDCoV-infected cells, which occurred concomitant with viral biosynthesis and irrespective of cell type. Pharmacological inhibition or knockdown of either SAPK significantly attenuated PDCoV replication, whereas addition of a signaling activator augmented virus infectivity. Moreover, pharmacological inhibition of JNK1/2 or p38 MAPK activation was innocuous to viral entry but significantly detrimental to post uncoating stages of the replication cycle. Remarkably, cytokine gene expression in PDCoV-infected IPEC-J2 cells was modified by inhibiting the activation of either SAPK. Collectively, these data indicate that JNK1/2 and p38 MAPK signaling pathways contribute to viral biosynthesis and regulate immune responses, thereby favoring the replication of PDCoV.
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Affiliation(s)
- Ji Hyun Jeon
- Animal Virology Laboratory, School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 FOUR KNU Creative BioResearch Group, Kyungpook National University, Daegu, 702-701, Republic of Korea.
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10
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Meng W, Gao SJ. Targeting XPO1 enhances innate immune response and inhibits KSHV lytic replication during primary infection by nuclear stabilization of the p62 autophagy adaptor protein. Cell Death Dis 2021; 12:29. [PMID: 33414399 PMCID: PMC7790339 DOI: 10.1038/s41419-020-03303-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 11/27/2020] [Accepted: 12/02/2020] [Indexed: 12/15/2022]
Abstract
Nucleocytoplasmic transport of signaling modulators is essential for regulating cellular responses to extracellular stimulation and stress, as well as pathogen infection. Exportin 1 (XPO1), also known as chromosomal maintenance 1 (CRM1), mediates nuclear export of proteins, rRNAs, snRNAs, and some mRNAs. In this study, we have identified an essential role of XPO1 in regulating Kaposi's sarcoma-associated herpesvirus (KSHV) lytic replication during primary infection of primary human umbilical vein endothelial cells. Treatment with an XPO1 inhibitor KPT-8602 and short hairpin RNA (shRNA)-mediated knockdown of XPO1 reduced KSHV lytic replication but had no effect on KSHV entry and trafficking. XPO1 inhibition induced retention of autophagy adaptor protein p62 (SQSTM1) in the nucleus, which enhanced activation of TBK1 and IRF3. As a result, nuclear accumulation of p62 increased expression of innate immune-related genes including IRF7, ISG15, IFIT1, IFIT2, and IFIT3, leading to a reduction of KSHV lytic replication. These results illustrate a novel mechanism by which XPO1 mediates innate immune response and KSHV replication, and identify XPO1 as a potential therapeutic target and KPT-8602 as a promising therapeutic agent for KSHV infection.
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Affiliation(s)
- Wen Meng
- UPMC Hillman Cancer Center, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shou-Jiang Gao
- UPMC Hillman Cancer Center, Department of Microbiology and Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
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Pseudomonas aeruginosa Stimulates Inflammation and Enhances Kaposi's Sarcoma Herpesvirus-Induced Cell Proliferation and Cellular Transformation through both Lipopolysaccharide and Flagellin. mBio 2020; 11:mBio.02843-20. [PMID: 33173008 PMCID: PMC7667028 DOI: 10.1128/mbio.02843-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammation triggered by innate immunity promotes carcinogenesis in cancer. Kaposi's sarcoma (KS), a hyperproliferative and inflammatory tumor caused by Kaposi's sarcoma-associated herpesvirus (KSHV) infection, is the most common cancer in AIDS patients. KSHV infection sensitizes cells to pathogen-associated molecular patterns (PAMPs). We examined the role of Pseudomonas aeruginosa, an opportunistic bacterium that can affect AIDS patients, in inflammation and cell proliferation of KSHV-transformed cells. P. aeruginosa stimulation increased cell proliferation and efficiency of colony formation in soft agar of KSHV-transformed rat primary mesenchymal precursor (KMM) cells but had no significant effect on the untransformed (MM) cells. P. aeruginosa stimulation also increased cell proliferation of KSHV-infected human B cells, BJAB, but not the uninfected cells. Mechanistically, P. aeruginosa stimulation resulted in increased inflammatory cytokines and activation of p38, ERK1/2, and JNK mitogen-activated protein kinase (MAPK) pathways in KMM cells while having no obvious effect on MM cells. P. aeruginosa induction of inflammation and MAPKs was observed with and without inhibition of the Toll-like receptor 4 (TLR4) pathway, while a flagellin-deleted mutant of P. aeruginosa required a functional TLR4 pathway to induce inflammation and MAPKs. Furthermore, treatment with either lipopolysaccharide (LPS) or flagellin alone was sufficient to induce inflammatory cytokines, activate MAPKs, and increase cell proliferation and efficiency of colony formation in soft agar of KMM cells. These results demonstrate that both LPS and flagellin are PAMPs that contribute to P. aeruginosa induction of inflammation in KSHV-transformed cells. Because AIDS-KS patients are susceptible to P. aeruginosa infection, our work highlights the preventive and therapeutic potential of targeting P. aeruginosa infection in these patients.IMPORTANCE Kaposi's sarcoma (KS), caused by infection with Kaposi's sarcoma-associated herpesvirus (KSHV), is one of the most common cancers in AIDS patients. KS is a highly inflammatory tumor, but how KSHV infection induces inflammation remains unclear. We have previously shown that KSHV infection upregulates Toll-like receptor 4 (TLR4), sensitizing cells to lipopolysaccharide (LPS) and Escherichia coli In the current study, we examined the role of Pseudomonas aeruginosa, an opportunistic bacterium that can affect AIDS patients, in inflammation and cell proliferation of KSHV-transformed cells. P. aeruginosa stimulation increased cell proliferation, inflammatory cytokines, and activation of growth and survival pathways in KSHV-transformed cells through two pathogen-associated molecular patterns, LPS and flagellin. Because AIDS-KS patients are susceptible to P. aeruginosa infection, our work highlights the preventive and therapeutic potential of targeting P. aeruginosa infection in these patients.
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Pavulraj S, Kamel M, Stephanowitz H, Liu F, Plendl J, Osterrieder N, Azab W. Equine Herpesvirus Type 1 Modulates Cytokine and Chemokine Profiles of Mononuclear Cells for Efficient Dissemination to Target Organs. Viruses 2020; 12:v12090999. [PMID: 32911663 PMCID: PMC7551999 DOI: 10.3390/v12090999] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 08/31/2020] [Accepted: 09/05/2020] [Indexed: 12/13/2022] Open
Abstract
Equine herpesvirus type 1 (EHV-1) causes encephalomyelopathy and abortion, for which cell-associated viremia and subsequent virus transfer to and replication in endothelial cells (EC) are responsible and prerequisites. Viral and cellular molecules responsible for efficient cell-to-cell spread of EHV-1 between peripheral blood mononuclear cells (PBMC) and EC remain unclear. We have generated EHV-1 mutants lacking ORF1, ORF2, and ORF17 genes, either individually or in combination. Mutant viruses were analyzed for their replication properties in cultured equine dermal cells, PBMC infection efficiency, virus-induced changes in the PBMC proteome, and cytokine and chemokine expression profiles. ORF1, ORF2, and ORF17 are not essential for virus replication, but ORF17 deletion resulted in a significant reduction in plaque size. Deletion of ORF2 and ORF17 gene significantly reduced cell-to-cell virus transfer from virus-infected PBMC to EC. EHV-1 infection of PBMC resulted in upregulation of several pathways such as Ras signaling, oxidative phosphorylation, platelet activation and leukocyte transendothelial migration. In contrast, chemokine signaling, RNA degradation and apoptotic pathways were downregulated. Deletion of ORF1, ORF2 and ORF17 modulated chemokine signaling and MAPK pathways in infected PBMC, which may explain the impairment of virus spread between PBMC and EC. The proteomic results were further confirmed by chemokine assays, which showed that virus infection dramatically reduced the cytokine/chemokine release in infected PBMC. This study uncovers cellular proteins and pathways influenced by EHV-1 after PBMC infection and provide an important resource for EHV-1 pathogenesis. EHV-1-immunomodulatory genes could be potential targets for the development of live attenuated vaccines or therapeutics against virus infection.
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Affiliation(s)
- Selvaraj Pavulraj
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Straße 7-13, 14163 Berlin, Germany; (S.P.); (M.K.); (N.O.)
| | - Mohamed Kamel
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Straße 7-13, 14163 Berlin, Germany; (S.P.); (M.K.); (N.O.)
- Department of Medicine and Infectious Diseases, Faculty of Veterinary Medicine, Cairo University, 12211 Cairo, Egypt
| | - Heike Stephanowitz
- Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Rössle-Str. 10, 13125 Berlin, Germany; (H.S.); (F.L.)
| | - Fan Liu
- Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Rössle-Str. 10, 13125 Berlin, Germany; (H.S.); (F.L.)
| | - Johanna Plendl
- Institut für Veterinäranatomie, Freie Universität Berlin, Koserstraße 20, 14195 Berlin, Germany;
| | - Nikolaus Osterrieder
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Straße 7-13, 14163 Berlin, Germany; (S.P.); (M.K.); (N.O.)
| | - Walid Azab
- Institut für Virologie, Robert von Ostertag-Haus, Zentrum für Infektionsmedizin, Freie Universität Berlin, Robert-von-Ostertag-Straße 7-13, 14163 Berlin, Germany; (S.P.); (M.K.); (N.O.)
- Correspondence: ; Tel.: +49-30-838-50087
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13
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Sperm associated antigen 9 promotes oncogenic KSHV-encoded interferon regulatory factor-induced cellular transformation and angiogenesis by activating the JNK/VEGFA pathway. PLoS Pathog 2020; 16:e1008730. [PMID: 32776977 PMCID: PMC7446834 DOI: 10.1371/journal.ppat.1008730] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 08/20/2020] [Accepted: 06/21/2020] [Indexed: 12/12/2022] Open
Abstract
Kaposi's sarcoma (KS), caused by Kaposi's sarcoma-associated herpesvirus (KSHV), is a highly angioproliferative disseminated tumor of endothelial cells commonly found in AIDS patients. We have recently shown that KSHV-encoded viral interferon regulatory factor 1 (vIRF1) mediates KSHV-induced cell motility (PLoS Pathog. 2019 Jan 30;15(1):e1007578). However, the role of vIRF1 in KSHV-induced cellular transformation and angiogenesis remains unknown. Here, we show that vIRF1 promotes angiogenesis by upregulating sperm associated antigen 9 (SPAG9) using two in vivo angiogenesis models including the chick chorioallantoic membrane assay (CAM) and the matrigel plug angiogenesis assay in mice. Mechanistically, vIRF1 interacts with transcription factor Lef1 to promote SPAG9 transcription. vIRF1-induced SPAG9 promotes the interaction of mitogen-activated protein kinase kinase 4 (MKK4) with JNK1/2 to increase their phosphorylation, resulting in enhanced VEGFA expression, angiogenesis, cell proliferation and migration. Finally, genetic deletion of ORF-K9 from KSHV genome abolishes KSHV-induced cellular transformation and impairs angiogenesis. Our results reveal that vIRF1 transcriptionally activates SPAG9 expression to promote angiogenesis and tumorigenesis via activating JNK/VEGFA signaling. These novel findings define the mechanism of KSHV induction of the SPAG9/JNK/VEGFA pathway and establish the scientific basis for targeting this pathway for treating KSHV-associated cancers.
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14
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Fiches GN, Zhou D, Kong W, Biswas A, Ahmed EH, Baiocchi RA, Zhu J, Santoso N. Profiling of immune related genes silenced in EBV-positive gastric carcinoma identified novel restriction factors of human gammaherpesviruses. PLoS Pathog 2020; 16:e1008778. [PMID: 32841292 PMCID: PMC7473590 DOI: 10.1371/journal.ppat.1008778] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 09/04/2020] [Accepted: 07/05/2020] [Indexed: 12/24/2022] Open
Abstract
EBV-associated gastric cancer (EBVaGC) is characterized by high frequency of DNA methylation. In this study, we investigated how epigenetic alteration of host genome contributes to pathogenesis of EBVaGC through the analysis of transcriptomic and epigenomic datasets from NIH TCGA (The Cancer Genome Atlas) consortium. We identified that immune related genes (IRGs) is a group of host genes preferentially silenced in EBV-positive gastric cancers through DNA hypermethylation. Further functional characterizations of selected IRGs reveal their novel antiviral activity against not only EBV but also KSHV. In particular, we showed that metallothionein-1 (MT1) and homeobox A (HOXA) gene clusters are down-regulated via EBV-driven DNA hypermethylation. Several MT1 isoforms suppress EBV lytic replication and release of progeny virions as well as KSHV lytic reactivation, suggesting functional redundancy of these genes. In addition, single HOXA10 isoform exerts antiviral activity against both EBV and KSHV. We also confirmed the antiviral effect of other dysregulated IRGs, such as IRAK2 and MAL, in scenario of EBV and KSHV lytic reactivation. Collectively, our results demonstrated that epigenetic silencing of IRGs is a viral strategy to escape immune surveillance and promote viral propagation, which is overall beneficial to viral oncogenesis of human gamma-herpesviruses (EBV and KSHV), considering that these IRGs possess antiviral activities against these oncoviruses.
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Affiliation(s)
- Guillaume N. Fiches
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Dawei Zhou
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Weili Kong
- Gladstone Institute of Virology and Immunology, University of California, San Francisco, California, United States of America
| | - Ayan Biswas
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Elshafa H. Ahmed
- Division of Hematology, Department of Internal Medicine, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Robert A. Baiocchi
- Division of Hematology, Department of Internal Medicine, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Jian Zhu
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, United States of America
| | - Netty Santoso
- Department of Pathology, Ohio State University College of Medicine, Columbus, Ohio, United States of America
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15
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Human Immunodeficiency Virus-Associated Exosomes Promote Kaposi's Sarcoma-Associated Herpesvirus Infection via the Epidermal Growth Factor Receptor. J Virol 2020; 94:JVI.01782-19. [PMID: 32051269 PMCID: PMC7163124 DOI: 10.1128/jvi.01782-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 02/06/2020] [Indexed: 12/12/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causal agent for Kaposi’s sarcoma (KS), the most common malignancy in HIV/AIDS patients. Oral transmission through saliva is considered the most common route for spreading the virus among HIV/AIDS patients. However, the role of HIV-specific components in the cotransfection of KSHV is unclear. We demonstrate that exosomes purified from the saliva of HIV-positive patients and secreted by HIV-infected T-cell lines promote KSHV infectivity in immortalized and primary oral epithelial cells. HIV-associated exosomes promote KSHV infection, which depends on HIV trans-activation response element (TAR) RNA and EGFR of oral epithelial cells, which can be targeted for reducing KSHV infection. These results reveal that HIV-associated exosomes are a risk factor for KSHV infection in the HIV-infected population. Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causal agent for Kaposi’s sarcoma (KS), the most common malignancy in people living with human immunodeficiency virus (HIV)/AIDS. The oral cavity is a major route for KSHV infection and transmission. However, how KSHV breaches the oral epithelial barrier for spreading to the body is not clear. Here, we show that exosomes purified from either the saliva of HIV-positive individuals or the culture supernatants of HIV-1-infected T-cell lines promote KSHV infectivity in immortalized and primary human oral epithelial cells. HIV-associated saliva exosomes contain the HIV trans-activation response element (TAR), Tat, and Nef RNAs but do not express Tat and Nef proteins. The TAR RNA in HIV-associated exosomes contributes to enhancing KSHV infectivity through the epidermal growth factor receptor (EGFR). An inhibitory aptamer against TAR RNA reduces KSHV infection facilitated by the synthetic TAR RNA in oral epithelial cells. Cetuximab, a monoclonal neutralizing antibody against EGFR, blocks HIV-associated exosome-enhanced KSHV infection. Our findings reveal that saliva containing HIV-associated exosomes is a risk factor for the enhancement of KSHV infection and that the inhibition of EGFR serves as a novel strategy for preventing KSHV infection and transmission in the oral cavity. IMPORTANCE Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causal agent for Kaposi’s sarcoma (KS), the most common malignancy in HIV/AIDS patients. Oral transmission through saliva is considered the most common route for spreading the virus among HIV/AIDS patients. However, the role of HIV-specific components in the cotransfection of KSHV is unclear. We demonstrate that exosomes purified from the saliva of HIV-positive patients and secreted by HIV-infected T-cell lines promote KSHV infectivity in immortalized and primary oral epithelial cells. HIV-associated exosomes promote KSHV infection, which depends on HIV trans-activation response element (TAR) RNA and EGFR of oral epithelial cells, which can be targeted for reducing KSHV infection. These results reveal that HIV-associated exosomes are a risk factor for KSHV infection in the HIV-infected population.
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16
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Kaposi's sarcoma-associated herpesvirus viral protein kinase phosphorylates extracellular signal-regulated kinase and activates MAPK/ERK signaling pathway. Biochem Biophys Res Commun 2020; 521:1083-1088. [PMID: 31733836 DOI: 10.1016/j.bbrc.2019.11.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 11/05/2019] [Indexed: 10/25/2022]
Abstract
Open reading frame 36 (ORF36) of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a serine/threonine-type viral protein kinase (vPK). Previous studies have examined the functions of KSHV vPK; however, its role in the activation of extracellular signal-regulated kinase (ERK1/2) has not yet been described to date. Using HEK 293 cell lines, we performed a human phospho-kinase array analysis to screen for MAPK signaling pathways kinases that are activated by KSHV vPK. In addition, we investigated the regulator protein phosphorylation of up/downstream ERK1/2 pathway; nuclear translocation of phosphorylated ERK1/2; and regulation of transcription factor, inflammatory cytokine, and pro-/anti-apoptotic factor by KSHV vPK transfection. Here, we demonstrated that KSHV vPK activates ERK1/2 signaling pathway and plays an important role in the activation of MAPK/ERK signaling pathway.
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17
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Chen J, Dai L, Goldstein A, Zhang H, Tang W, Forrest JC, Post SR, Chen X, Qin Z. Identification of new antiviral agents against Kaposi's sarcoma-associated herpesvirus (KSHV) by high-throughput drug screening reveals the role of histamine-related signaling in promoting viral lytic reactivation. PLoS Pathog 2019; 15:e1008156. [PMID: 31790497 PMCID: PMC6907871 DOI: 10.1371/journal.ppat.1008156] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 12/12/2019] [Accepted: 10/23/2019] [Indexed: 12/11/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) causes several human cancers, such as Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). Current treatment options for KSHV infection and virus associated diseases are sometimes ineffective, therefore, more effectively antiviral agents are urgently needed. As a herpesvirus, lytic replication is critical for KSHV pathogenesis and oncogenesis. In this study, we have established a high-throughput screening assay by using an inducible KSHV+ cell-line, iSLK.219. After screening a compound library that consisted of 1280 Food and Drug Administration (FDA)-approved drugs, 15 hit compounds that effectively inhibited KSHV virion production were identified, most of which have never been reported with anti-KSHV activities. Interestingly, 3 of these drugs target histamine receptors or signaling. Our data further confirmed that antagonists targeting different histamine receptors (HxRs) displayed excellent inhibitory effects on KSHV lytic replication from induced iSLK.219 or BCBL-1 cells. In contrast, histamine and specific agonists of HxRs promoted viral lytic replication from induced iSLK.219 or KSHV-infected primary cells. Mechanistic studies indicated that downstream MAPK and PI3K/Akt signaling pathways were required for histamine/receptors mediated promotion of KSHV lytic replication. Direct knockdown of HxRs in iSLK.219 cells effectively blocked viral lytic gene expression during induction. Using samples from a cohort of HIV+ patients, we found that the KSHV+ group has much higher levels of histamine in their plasma and saliva than the KSHV- group. Taken together, our data have identified new anti-KSHV agents and provided novel insights into the molecular bases of host factors that contribute to lytic replication and reactivation of this oncogenic herpesvirus.
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Affiliation(s)
- Jungang Chen
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Lu Dai
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Alana Goldstein
- Departments of Diagnostic Sciences, School of Dentistry, Louisiana State University Health Sciences Center, New Orleans, Louisiana, United States of America
| | - Haiwei Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Hubei, China
| | - Wei Tang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Hubei, China
| | - J. Craig Forrest
- Department of Microbiology & Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Steven R. Post
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Xulin Chen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Hubei, China
- Guangdong Key Laboratory of Virology, Institute of Medical Microbiology, Jinan University, Guangzhou, China
- * E-mail: (XC); (ZQ)
| | - Zhiqiang Qin
- Department of Pathology, Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
- * E-mail: (XC); (ZQ)
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18
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Mirzaei H, Khodadad N, Karami C, Pirmoradi R, Khanizadeh S. The AP-1 pathway; A key regulator of cellular transformation modulated by oncogenic viruses. Rev Med Virol 2019; 30:e2088. [PMID: 31788897 DOI: 10.1002/rmv.2088] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 09/16/2019] [Accepted: 09/16/2019] [Indexed: 12/13/2022]
Abstract
Cancer progression is critically associated with modulation of host cell signaling pathways. Activator protein-1 (AP-1) signaling is one such pathway whose deregulation renders the host more susceptible to cancer development. Oncogenic viruses, including hepatitis B virus, hepatitis C virus, human papilloma virus, Epstein-Barr virus, human T-cell lymphotropic virus type 1, and Kaposi's sarcoma-associated herpes virus, are common causes of cancer. This review discusses how these oncoviruses by acting through various aspects of the host cell signaling machinery such as the AP-1 pathway might affect oncoviral tumorigenesis, replication, and pathogenesis. The review also briefly considers how the pathway might be targeted during infections with these oncogenic viruses.
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Affiliation(s)
- Habibollah Mirzaei
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Nastaran Khodadad
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Infectious and Tropical Disease Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Chiman Karami
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Infectious and Tropical Disease Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Roya Pirmoradi
- Department of Virology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Sayyad Khanizadeh
- Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran.,Department of Virology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran
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19
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Wong JP, Stuhlmiller TJ, Giffin LC, Lin C, Bigi R, Zhao J, Zhang W, Bravo Cruz AG, Park SI, Earp HS, Dittmer DP, Frye SV, Wang X, Johnson GL, Damania B. Kinome profiling of non-Hodgkin lymphoma identifies Tyro3 as a therapeutic target in primary effusion lymphoma. Proc Natl Acad Sci U S A 2019; 116:16541-16550. [PMID: 31346082 PMCID: PMC6697815 DOI: 10.1073/pnas.1903991116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Non-Hodgkin lymphomas (NHLs) make up the majority of lymphoma diagnoses and represent a very diverse set of malignancies. We sought to identify kinases uniquely up-regulated in different NHL subtypes. Using multiplexed inhibitor bead-mass spectrometry (MIB/MS), we found Tyro3 was uniquely up-regulated and important for cell survival in primary effusion lymphoma (PEL), which is a viral lymphoma infected with Kaposi's sarcoma-associated herpesvirus (KSHV). Tyro3 was also highly expressed in PEL cell lines as well as in primary PEL exudates. Based on this discovery, we developed an inhibitor against Tyro3 named UNC3810A, which hindered cell growth in PEL, but not in other NHL subtypes where Tyro3 was not highly expressed. UNC3810A also significantly inhibited tumor progression in a PEL xenograft mouse model that was not seen in a non-PEL NHL model. Taken together, our data suggest Tyro3 is a therapeutic target for PEL.
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Affiliation(s)
- Jason P Wong
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Timothy J Stuhlmiller
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Louise C Giffin
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Carolina Lin
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Rachele Bigi
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Microbiology and Immunology and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Jichen Zhao
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Weihe Zhang
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Ariana G Bravo Cruz
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Steven I Park
- Department of Medicine and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - H Shelton Earp
- Department of Medicine and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Dirk P Dittmer
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Department of Microbiology and Immunology and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Stephen V Frye
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Xiaodong Wang
- Center for Integrative Chemical Biology and Drug Discovery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599;
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Gary L Johnson
- Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599;
| | - Blossom Damania
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599;
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20
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DuShane JK, Maginnis MS. Human DNA Virus Exploitation of the MAPK-ERK Cascade. Int J Mol Sci 2019; 20:ijms20143427. [PMID: 31336840 PMCID: PMC6679023 DOI: 10.3390/ijms20143427] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/09/2019] [Accepted: 07/11/2019] [Indexed: 12/19/2022] Open
Abstract
The extracellular signal-regulated kinases (ERKs) comprise a particular branch of the mitogen-activated protein kinase cascades (MAPK) that transmits extracellular signals into the intracellular environment to trigger cellular growth responses. Similar to other MAPK cascades, the MAPK-ERK pathway signals through three core kinases—Raf, MAPK/ERK kinase (MEK), and ERK—which drive the signaling mechanisms responsible for the induction of cellular responses from extracellular stimuli including differentiation, proliferation, and cellular survival. However, pathogens like DNA viruses alter MAPK-ERK signaling in order to access DNA replication machineries, induce a proliferative state in the cell, or even prevent cell death mechanisms in response to pathogen recognition. Differential utilization of this pathway by multiple DNA viruses highlights the dynamic nature of the MAPK-ERK pathway within the cell and the importance of its function in regulating a wide variety of cellular fates that ultimately influence viral infection and, in some cases, result in tumorigenesis.
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Affiliation(s)
- Jeanne K DuShane
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04401, USA
| | - Melissa S Maginnis
- Department of Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04401, USA.
- Graduate School in Biomedical Sciences and Engineering, The University of Maine, Orono, ME 04401, USA.
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21
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He M, Cheng F, da Silva SR, Tan B, Sorel O, Gruffaz M, Li T, Gao SJ. Molecular Biology of KSHV in Relation to HIV/AIDS-Associated Oncogenesis. Cancer Treat Res 2019; 177:23-62. [PMID: 30523620 DOI: 10.1007/978-3-030-03502-0_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Discovered in 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) has been associated with four human malignancies including Kaposi's sarcoma, primary effusion lymphoma, a subset of multicentric Castleman's disease, and KSHV inflammatory cytokine syndrome. These malignancies mostly occur in immunocompromised patients including patients with acquired immunodeficiency syndrome and often cause significant mortality because of the lack of effective therapies. Significant progresses have been made to understand the molecular basis of KSHV infection and KSHV-induced oncogenesis in the last two decades. This chapter provides an update on the recent advancements focusing on the molecular events of KSHV primary infection, the mechanisms regulating KSHV life cycle, innate and adaptive immunity, mechanism of KSHV-induced tumorigenesis and inflammation, and metabolic reprogramming in KSHV infection and KSHV-transformed cells.
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Affiliation(s)
- Meilan He
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Fan Cheng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Suzane Ramos da Silva
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Brandon Tan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Océane Sorel
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Marion Gruffaz
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Tingting Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Shou-Jiang Gao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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Moriguchi M, Watanabe T, Kadota A, Fujimuro M. Capsaicin Induces Apoptosis in KSHV-Positive Primary Effusion Lymphoma by Suppressing ERK and p38 MAPK Signaling and IL-6 Expression. Front Oncol 2019; 9:83. [PMID: 30838176 PMCID: PMC6389641 DOI: 10.3389/fonc.2019.00083] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/29/2019] [Indexed: 01/28/2023] Open
Abstract
Primary effusion lymphoma (PEL) is defined as a rare subtype of non-Hodgkin's B-cell lymphoma which is caused by Kaposi's sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients. PEL is an aggressive lymphoma and is frequently resistant to conventional chemotherapies. Therefore, it is critical to investigate novel therapeutic options for PEL. Capsaicin is a pungent component of chili pepper and possesses unique pharmacological effects, such as pain relief, anti-microbial and anti-cancer properties. Here, we demonstrate that capsaicin markedly inhibited the growth of KSHV latently infected PEL cells by inhibiting ERK, p38 MAPK and expression hIL-6, which are known to contribute to PEL growth and survival. The underlying mechanism of action by capsaicin was through the inhibition of ERK and p38 MAPK phosphorylation and signaling that affected hIL-6 expression. As a result, capsaicin induced apoptosis in PEL cells in a caspase-9 dependent manner. In line with these results, ERK (U0126) and p38 MAPK (SB203580) specific signaling inhibitors suppressed hIL-6 expression and attenuated cell growth in PEL cells. Furthermore, the addition of hIL-6 neutralizing antibody to culture medium suppressed the growth of PEL cells. We also demonstrate that capsaicin suppressed PEL cell growth in the absence of nascent viral replication. Finally, we confirmed ex vivo treatment of capsaicin attenuated PEL development in SCID mice. Taken together, capsaicin could represent a lead compound for PEL therapy without the risk of de novo KSHV infection.
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Affiliation(s)
- Misato Moriguchi
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Tadashi Watanabe
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Ayano Kadota
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Masahiro Fujimuro
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
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K15 Protein of Kaposi's Sarcoma Herpesviruses Increases Endothelial Cell Proliferation and Migration through Store-Operated Calcium Entry. Viruses 2018; 10:v10060282. [PMID: 29795033 PMCID: PMC6024707 DOI: 10.3390/v10060282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 05/06/2018] [Accepted: 05/09/2018] [Indexed: 01/11/2023] Open
Abstract
Kaposi's sarcoma (KS) is a tumor of the vascular endothelium that is caused by Kaposi's sarcoma-associated herpesvirus (KSHV). K15 of KSHV is a specific gene encoding a transmembrane protein. Two highly different forms of K15, the predominant (K15P) and minor (K15M) have been identified in different KSHV strains. In genomic locations and protein topology, two K15 alleles resemble the latent membrane protein (LMP) 1 and LMP2A of Epstein⁻Barr virus. Both K15 proteins have motifs similar to those found in LMP1 and LMP2A. K15 therefore seems to be a hybrid of a distant evolutionary relative of LMP1 and LMP2A. Ca2+ is a second messenger and participates in numerous activities in cells, like proliferation, migration and metastasis. It has been found previously that LMP1 increased Ca2+ influx through store-operated calcium channels and blockade of LMP1 reduced store-operated Ca2+ entry (SOCE). LMP2A has similar activity. So we sought to determine whether K15 had similar activity. We showed that K15P induced Ca2+ influx and enhanced expression of Orail1, which is a vital protein in SOCE, and overexpression of K15P improved cell motility. Mutant K15P did not show these activities in HEK-293T and EA.hy 926 cells. Our results showed that K15P increased cell proliferation and migration though SOCE and established a novel mechanism for the development of KS and KSHV-associated diseases.
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Watanabe T, Sugimoto A, Hosokawa K, Fujimuro M. Signal Transduction Pathways Associated with KSHV-Related Tumors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1045:321-355. [PMID: 29896674 DOI: 10.1007/978-981-10-7230-7_15] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Signal transduction pathways play a key role in the regulation of cell growth, cell differentiation, cell survival, apoptosis, and immune responses. Bacterial and viral pathogens utilize the cell signal pathways by encoding their own proteins or noncoding RNAs to serve their survival and replication in infected cells. Kaposi's sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is classified as a rhadinovirus in the γ-herpesvirus subfamily and was the eighth human herpesvirus to be discovered from Kaposi's sarcoma specimens. KSHV is closely associated with an endothelial cell malignancy, Kaposi's sarcoma, and B-cell malignancies, primary effusion lymphoma, and multicentric Castleman's disease. Recent studies have revealed that KSHV manipulates the cellular signaling pathways to achieve persistent infection, viral replication, cell proliferation, anti-apoptosis, and evasion of immune surveillance in infected cells. This chapter summarizes recent developments in our understanding of the molecular mechanisms used by KSHV to interact with the cell signaling machinery.
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Affiliation(s)
- Tadashi Watanabe
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Atsuko Sugimoto
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Kohei Hosokawa
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan
| | - Masahiro Fujimuro
- Department of Cell Biology, Kyoto Pharmaceutical University, Kyoto, Japan.
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Antiviral activity of ginsenoside Rg3 isomers against gammaherpesvirus through inhibition of p38- and JNK-associated pathways. J Funct Foods 2018. [DOI: 10.1016/j.jff.2017.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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Full-Length Isoforms of Kaposi's Sarcoma-Associated Herpesvirus Latency-Associated Nuclear Antigen Accumulate in the Cytoplasm of Cells Undergoing the Lytic Cycle of Replication. J Virol 2017; 91:JVI.01532-17. [PMID: 28978712 DOI: 10.1128/jvi.01532-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/29/2017] [Indexed: 01/09/2023] Open
Abstract
The latency-associated nuclear antigen (LANA) of the Kaposi's sarcoma-associated herpesvirus (KSHV) performs a variety of functions to establish and maintain KSHV latency. During latency, LANA localizes to discrete punctate spots in the nucleus, where it tethers viral episomes to cellular chromatin and interacts with nuclear components to regulate cellular and viral gene expression. Using highly sensitive tyramide signal amplification, we determined that LANA localizes to the cytoplasm in different cell types undergoing the lytic cycle of replication after de novo primary infection and after spontaneous, tetradecanoyl phorbol acetate-, or open reading frame 50 (ORF50)/replication transactivator (RTA)-induced activation. We confirmed the presence of cytoplasmic LANA in a subset of cells in lytically active multicentric Castleman disease lesions. The induction of cellular migration by scratch-wounding confluent cell cultures, culturing under subconfluent conditions, or induction of cell differentiation in primary cultures upregulated the number of cells permissive for primary lytic KSHV infection. The induction of lytic replication was characterized by high-level expression of cytoplasmic LANA and nuclear ORF59, a marker of lytic replication. Subcellular fractionation studies revealed the presence of multiple isoforms of LANA in the cytoplasm of ORF50/RTA-activated Vero cells undergoing primary infection. Mass spectrometry analysis demonstrated that cytoplasmic LANA isoforms were full length, containing the N-terminal nuclear localization signal. These results suggest that trafficking of LANA to different subcellular locations is a regulated phenomenon, which allows LANA to interact with cellular components in different compartments during both the latent and the replicative stages of the KSHV life cycle.IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) causes AIDS-related malignancies, including lymphomas and Kaposi's sarcoma. KSHV establishes lifelong infections using its latency-associated nuclear antigen (LANA). During latency, LANA localizes to the nucleus, where it connects viral and cellular DNA complexes and regulates gene expression, allowing the virus to maintain long-term infections. Our research shows that intact LANA traffics to the cytoplasm of cells undergoing permissive lytic infections and latently infected cells in which the virus is induced to replicate. This suggests that LANA plays important roles in the cytoplasm and nuclear compartments of the cell during different stages of the KSHV life cycle. Determining cytoplasmic function and mechanism for regulation of the nuclear localization of LANA will enhance our understanding of the biology of this virus, leading to therapeutic approaches to eliminate infection and block its pathological effects.
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Gonnella R, Yadav S, Gilardini Montani MS, Granato M, Santarelli R, Garufi A, D'Orazi G, Faggioni A, Cirone M. Oxidant species are involved in T/B-mediated ERK1/2 phosphorylation that activates p53-p21 axis to promote KSHV lytic cycle in PEL cells. Free Radic Biol Med 2017; 112:327-335. [PMID: 28801242 DOI: 10.1016/j.freeradbiomed.2017.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/31/2017] [Accepted: 08/05/2017] [Indexed: 12/18/2022]
Abstract
KSHV is a gammaherpesvirus strongly associated to human cancers such as Primary Effusion Lymphoma (PEL) and Kaposi's Sarcoma. The naturally virus-infected tumor cells usually display latent infection since a minority of cells undergoes spontaneous viral replication. The lytic cycle can be induced in vitro upon appropriate stimuli such as TPA (T), alone or in combination with butyrate (B), (T/B). In previous studies, Protein Kinase C (PKC) δ, Extracellular Signal-regulated Kinase1/2 (ERK1/2) and p53-p21 axis have been separately reported to play a role in KSHV reactivation from latency. Here, we found that these pathways were interconnected to induce KSHV lytic cycle in PEL cells treated with T/B. T/B also increased H2O2 that played an important role in the activation of these pathways. Oxidant specie production correlated with PKC δ activation, as the PKC δ inhibitor rottlerin reduced both H2O2 and KSHV lytic antigen expression. H2O2 contributed to T/B-mediated ERK1/2 activation that mediated p53 phosphorylation at serine 15 (Ser15) and increased p21 expression. Oxidant specie inhibition by quercetin indeed strongly reduced the activation of these pathways, lytic antigen expression and interestingly it also increased T/B-induced cell death. The use of ERK inhibitor PD98059 or p53 silencing demonstrated the importance of p53Ser15 phosphorylation and of p53-p21 axis in KSHV lytic cycle activation. Understanding the role of oxidant species and the molecular mechanisms involved in KSHV lytic cycle induction is particularly important since oxidant species represent the most physiological stimulus for viral reactivation in vivo and it is known that viral production contributes to the maintenance/progression of KSHV associated malignancies.
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Affiliation(s)
- Roberta Gonnella
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
| | - Shivangi Yadav
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
| | | | - Marisa Granato
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
| | - Roberta Santarelli
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
| | - Alessia Garufi
- Department of Research, Advanced Diagnostics, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
| | - Gabriella D'Orazi
- Department of Research, Advanced Diagnostics, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy; Department of Medical Sciences, University 'G. d'Annunzio', 66013 Chieti, Italy.
| | - Alberto Faggioni
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
| | - Mara Cirone
- Department of Experimental Medicine, Sapienza University, 00100 Rome, Italy.
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1, 25(OH)2 D3 Induces Reactivation and Death of Kaposi's Sarcoma-Associated Herpesvirus of Primary Effusion Lymphoma cells. Sci Rep 2017; 7:12438. [PMID: 28963501 PMCID: PMC5622028 DOI: 10.1038/s41598-017-12676-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 09/05/2017] [Indexed: 12/31/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) a gammaherpesvirus establishes perennial latency in the host with periodic reactivation. Occasionally change in the physiological condition like hypoxia, host cell differentiation can trigger the lytic switch and reactivation of the virus. The biologically active form of 1, 25(OH)2 D3 plays a critical role in the regulation of various physiological processes (e.g. regulation of mineral homeostasis and control of bone metabolism). Apart from its role in host physiology, 1, 25(OH)2 D3 has been implicated as a potential agent for the prevention and/or treatment of many a tumors. Here we show that 1, 25(OH)2 D3 induces both death of Kaposi sarcoma associated herpesvirus infected PEL cells and KSHV replication. 1, 25(OH)2 D3 mediated inhibition of proliferation was associated with apoptosis of the PEL cells, and virus reactivation. In addition, p38 signalling is required for KSHV reactivation. Furthermore, treatment of PEL cells with p38 inhibitor abrogated the expression of ORF57, thus blocking lytic switch. Furthermore, silencing of VDR resulted in reduced ORF57 expression compared to the control cells, signifying the potential role of 1, 25(OH)2 D3 in KSHV reactivation. Thus, our studies have revealed a novel role of 1, 25(OH)2 D3 in the regulation of KSHV reactivation and PEL cell death.
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Wang X, Zou Z, Deng Z, Liang D, Zhou X, Sun R, Lan K. Male hormones activate EphA2 to facilitate Kaposi's sarcoma-associated herpesvirus infection: Implications for gender disparity in Kaposi's sarcoma. PLoS Pathog 2017; 13:e1006580. [PMID: 28957431 PMCID: PMC5619820 DOI: 10.1371/journal.ppat.1006580] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/14/2017] [Indexed: 12/12/2022] Open
Abstract
There is increasing consensus that males are more vulnerable than females to infection by several pathogens. However, the underlying mechanism needs further investigation. Here, it was showed that knockdown of androgen receptor (AR) expression or pre-treatment with 5α-dihydrotestosterone, the AR agonist, led to a considerably dysregulated Kaposi's sarcoma-associated herpesvirus (KSHV) infection. In endothelial cells, membrane-localized AR promoted the endocytosis and nuclear trafficking of KSHV. The AR interacted with ephrin receptor A2 (EphA2) and increased its phosphorylation at residue Ser897, which was specifically upregulated upon KSHV infection. This phosphorylation resulted from the AR-mediated recruitment of Src, which resulted in the activation of p90 ribosomal S6 kinase 1 (RSK1), which directly phosphorylates EphA2 at Ser897. Finally, the EphA2-mediated entry of KSHV was abolished in a Ser897Asn EphA2 mutant. Taken together, membrane-localized AR was identified as a KSHV entry factor that cooperatively activates Src/RSK1/EphA2 signaling, which subsequently promotes KSHV infection of both endothelial and epithelial cells.
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Affiliation(s)
- Xing Wang
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei Province, China
| | - Zhe Zou
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei Province, China
| | - Zhaohui Deng
- Hospital of Xinjiang Production and Construction Corps, Urumqi, Xinjiang, China
| | - Deguang Liang
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei Province, China
| | - Xin Zhou
- Cancer Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China
| | - Rui Sun
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei Province, China
| | - Ke Lan
- State Key Laboratory of Virology, College of Life Science, Wuhan University, Wuhan, Hubei Province, China
- * E-mail:
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Abere B, Mamo TM, Hartmann S, Samarina N, Hage E, Rückert J, Hotop SK, Büsche G, Schulz TF. The Kaposi's sarcoma-associated herpesvirus (KSHV) non-structural membrane protein K15 is required for viral lytic replication and may represent a therapeutic target. PLoS Pathog 2017; 13:e1006639. [PMID: 28938025 PMCID: PMC5627962 DOI: 10.1371/journal.ppat.1006639] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 10/04/2017] [Accepted: 09/09/2017] [Indexed: 12/18/2022] Open
Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) is the infectious cause of the highly vascularized tumor Kaposi’s sarcoma (KS), which is characterized by proliferating spindle cells of endothelial origin, extensive neo-angiogenesis and inflammatory infiltrates. The KSHV K15 protein contributes to the angiogenic and invasive properties of KSHV-infected endothelial cells. Here, we asked whether K15 could also play a role in KSHV lytic replication. Deletion of the K15 gene from the viral genome or its depletion by siRNA lead to reduced virus reactivation, as evidenced by the decreased expression levels of KSHV lytic proteins RTA, K-bZIP, ORF 45 and K8.1 as well as reduced release of infectious virus. Similar results were found for a K1 deletion virus. Deleting either K15 or K1 from the viral genome also compromised the ability of KSHV to activate PLCγ1, Erk1/2 and Akt1. In infected primary lymphatic endothelial (LEC-rKSHV) cells, which have previously been shown to spontaneously display a viral lytic transcription pattern, transfection of siRNA against K15, but not K1, abolished viral lytic replication as well as KSHV-induced spindle cell formation. Using a newly generated monoclonal antibody to K15, we found an abundant K15 protein expression in KS tumor biopsies obtained from HIV positive patients, emphasizing the physiological relevance of our findings. Finally, we used a dominant negative inhibitor of the K15-PLCγ1 interaction to establish proof of principle that pharmacological intervention with K15-dependent pathways may represent a novel approach to block KSHV reactivation and thereby its pathogenesis. Both the latent and lytic replication phases of the KSHV life cycle are thought to contribute to its persistence and pathogenesis. The non-structural signaling membrane protein K15 is involved in the angiogenic and invasive properties of KSHV-infected endothelial cells. Here we show that the K15 protein is required for virus replication, early viral gene expression and virus production through its activation of the cellular signaling pathways PLCγ1 and Erk 1/2. K15 is abundantly expressed in KSHV-infected lymphatic endothelial cells (LECs) and contributes to KSHV-induced endothelial spindle cell formation. The abundant K15 protein expression observed in LECs is also observed in KS tumors. We also show that it may be possible to target K15 in order to intervene therapeutically with KSHV lytic replication and pathogenesis.
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Affiliation(s)
- Bizunesh Abere
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Tamrat M. Mamo
- Institute of Molecular Biology, Hannover Medical School, Hannover, Germany
| | - Silke Hartmann
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Naira Samarina
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Elias Hage
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Jessica Rückert
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
| | - Sven-Kevin Hotop
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
- Department of Chemical Biology, Helmholtz Center for Infection Research, Braunschweig, Germany
| | - Guntram Büsche
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | - Thomas F. Schulz
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Centre for Infection Research, Hannover–Braunschweig Site, Germany
- * E-mail:
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Sarkar R, Verma SC. Egr-1 regulates RTA transcription through a cooperative involvement of transcriptional regulators. Oncotarget 2017; 8:91425-91444. [PMID: 29207655 PMCID: PMC5710935 DOI: 10.18632/oncotarget.20648] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 07/26/2017] [Indexed: 11/25/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) regulates the host cellular environment to establish life-long persistent infection by manipulating cellular signaling pathways, with approximately 1- 5% of cells undergoing lytic reactivation during the course of infection. Egr-1 (Early Growth Response Factor-1) is one such cellular transcription factor, which gets phosphorylated during the lytic phase of viral life cycle to perpetrate its function. This study demonstrates the mechanism of how Egr-1 mediates transcription of the immediate early gene, RTA (Replication and transcription activator), which is the lytic switch gene of KSHV. Egr-1 depleted KSHV infected cells exhibited reduced expression of RTA. Also, an increase in Egr-1 phosphorylation led to a higher virion production, which was suppressed in the presence of p38 and Raf inhibitors. Reporter assays showed that coexpression of Egr-1 and CBP (CREB-binding protein) enhances RTA promoter activity as compared to the expression of either Egr-1 or CBP alone. Binding of Egr-1 and CBP at RTA promoter was analyzed by chromatin immunoprecipitation assay (ChIP), which showed an enhanced accumulation during viral reactivation. Mutation in Egr-1 binding site of the RTA promoter eliminated Egr-1 response on promoter activation. Furthermore, de novo infection of THP-1 (monocytic) and HUVECs (endothelial) cells showed an upregulation of Egr-1 phosphorylation, whereas depletion of Egr-1 reduced the mRNA levels of RTA during primary infection. Together, these results demonstrate a cooperative role of Egr-1 and CBP in mediating RTA transcription, which significantly improves our understanding of the involvement of cellular factors controlling RTA transcription in KSHV pathogenesis.
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Affiliation(s)
- Roni Sarkar
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Subhash C Verma
- Department of Microbiology and Immunology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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32
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Wong JP, Damania B. Modulation of oncogenic signaling networks by Kaposi's sarcoma-associated herpesvirus. Biol Chem 2017; 398:911-918. [PMID: 28284028 DOI: 10.1515/hsz-2017-0101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/08/2017] [Indexed: 01/07/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of three human malignancies: Kaposi's sarcoma, primary effusion lymphoma, and multicentric Castleman's disease. To persist and replicate within host cells, KSHV encodes proteins that modulate different signaling pathways. Manipulation of cell survival and proliferative networks by KSHV can promote the development of KSHV-associated malignancies. In this review, we discuss recent updates on KSHV pathogenesis and the viral life cycle. We focus on proteins encoded by KSHV that modulate the phosphatidylinositol-4,5-bisphosphate 3 kinase and extracellular signal-regulated kinases 1/2 pathways to create an environment favorable for viral replication and the development of KSHV malignancies.
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Zhong C, Xu M, Wang Y, Xu J, Yuan Y. An APE1 inhibitor reveals critical roles of the redox function of APE1 in KSHV replication and pathogenic phenotypes. PLoS Pathog 2017; 13:e1006289. [PMID: 28380040 PMCID: PMC5381946 DOI: 10.1371/journal.ppat.1006289] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 03/11/2017] [Indexed: 01/04/2023] Open
Abstract
APE1 is a multifunctional protein with a DNA base excision repair function in its C-terminal domain and a redox activity in its N-terminal domain. The redox function of APE1 converts certain transcription factors from inactive oxidized to active reduced forms. Given that among the APE1-regulated transcription factors many are critical for KSHV replication and pathogenesis, we investigated whether inhibition of APE1 redox function blocks KSHV replication and Kaposi’s sarcoma (KS) phenotypes. With an shRNA-mediated silencing approach and a known APE-1 redox inhibitor, we demonstrated that APE1 redox function is indeed required for KSHV replication as well as KSHV-induced angiogenesis, validating APE1 as a therapeutic target for KSHV-associated diseases. A ligand-based virtual screening yielded a small molecular compound, C10, which is proven to bind to APE1. C10 exhibits low cytotoxicity but efficiently inhibits KSHV lytic replication (EC50 of 0.16 μM and selective index of 165) and KSHV-mediated pathogenic phenotypes including cytokine production, angiogenesis and cell invasion, demonstrating its potential to become an effective drug for treatment of KS. As a major AIDS-associated malignancy, Kaposi’s sarcoma (KS) is caused by Kaposi’s sarcoma-associated herpesvirus (KSHV). Currently there is no definitive cure for KS. In this study, we identified a cellular protein, namely APE1, as an effective therapeutic target for blocking KSHV replication and inhibiting the development of KS phenotypes. We showed that the redox function of APE1 is absolutely required for KSHV replication, virally induced cytokine secretion and angiogenesis. Blockade of APE1 expression or inhibition of APE1 redox activity led to inhibition of KSHV replication and reduction of cytokine release and angiogenesis. Furthermore, we identified a novel small molecular compound, C10, which exhibited specific inhibitory activity on APE1 redox function and was demonstrated to efficiently inhibit KSHV replication and paracrine-mediated KS phenotypes such as angiogenesis and cell invasion. As a potent inhibitor of APE1 redox, C10 not only has value in development of a novel therapeutics for KS, but also may be used in therapies for other human diseases such as leukemia, pancreatic cancer and macular degeneration.
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Affiliation(s)
- Canrong Zhong
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Mengyang Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Yan Wang
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Guanghua School of Stomatology, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, Guangdong, China
- * E-mail: (YY); (JX)
| | - Yan Yuan
- Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Key Laboratory of Tropical Disease Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, Guangdong, China
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail: (YY); (JX)
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Altering the Anti-inflammatory Lipoxin Microenvironment: a New Insight into Kaposi's Sarcoma-Associated Herpesvirus Pathogenesis. J Virol 2016; 90:11020-11031. [PMID: 27681120 DOI: 10.1128/jvi.01491-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 08/23/2016] [Indexed: 12/29/2022] Open
Abstract
Lipoxins are host anti-inflammatory molecules that play a vital role in restoring tissue homeostasis. The efficacy of lipoxins and their analog epilipoxins in treating inflammation and its associated diseases has been well documented. Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL) are two well-known inflammation related diseases caused by Kaposi's sarcoma-associated herpesvirus (KSHV). Controlling inflammation is one of the strategies adopted to treat KS and PEL, a primary motivation for exploring and evaluating the therapeutic potential of using lipoxins. This study documents how KSHV manipulates and downregulates the secretion of the anti-inflammatory lipoxin A4 in host cells and the viral factors involved in this process using in vitro KS and PEL cells as models. The presence of the lipoxin A4 receptor/formyl peptidyl receptor (ALX/FPR) in KS patient tissue sections and in vitro KS and PEL cell models offers a novel possibility for treating KS and PEL with lipoxins. Treating de novo KSHV-infected endothelial cells with lipoxin and epilipoxin creates an anti-inflammatory environment by decreasing the levels of NF-κB, AKT, ERK1/2, COX-2, and 5-lipoxygenase. Lipoxin treatment on CRISPR/CAS9 technology-mediated ALX/FPR gene deletion revealed the importance of the lipoxin receptor ALX for effective lipoxin signaling. A viral microRNA (miRNA) cluster was identified as the primary factor contributing to the downregulation of lipoxin A4 secretion in host cells. The KSHV miRNA cluster probably targets enzyme 15-lipoxygenase, which is involved in lipoxin A4 synthesis. This study provides a new insight into the potential treatment of KS and PEL using nature's own anti-inflammatory molecule, lipoxin. IMPORTANCE KSHV infection has been shown to upregulate several host proinflammatory factors, which aid in its survival and pathogenesis. The influence of KSHV infection on anti-inflammatory molecules is not well studied. Since current treatment methods for KS and PEL are fraught with unwanted side effects and low efficiency, the search for new therapeutics is therefore imperative. The use of nature's own molecule lipoxin as a drug is promising. This study opens up new domains in KSHV research focusing on how the virus modulates lipoxin secretion and warrants further investigation of the therapeutic potential of lipoxin using in vitro cell models for KS and PEL.
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Kang S, Jeon C, Im K, Song MJ, Min H. Regulation of the viral life cycle by murine gammaherpesvirus 68 microRNAs. Arch Virol 2016; 162:657-667. [PMID: 27837274 DOI: 10.1007/s00705-016-3150-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 11/01/2016] [Indexed: 10/20/2022]
Abstract
γ-Herpesviruses (γHV) such as Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus are important human pathogens involved in lymphoproliferation and tumorigenesis. Murine gammaherpesvirus 68 (MHV-68, γHV-68) is an effective model for the study of γHV pathogenesis and host-virus interaction because it is closely related to human γHV. Similarly to human γHV, MHV-68 encodes 15 microRNAs (miRNAs). Although their functions remain unknown, they are thought to regulate the viral life cycle or host-virus interactions, similarly to other human γHV. Herein, we established stable cell lines expressing MHV-68 miRNAs and investigated the role of MHV-68 miRNAs in the regulation of viral life cycle. We found that mghv-miR-M1-1, -3, -5, -7, -8, -9, -10, -11, -13, and -15 repressed MHV-68 lytic replication by down-regulating expression of the replication and transcription activator (RTA) gene, whereas mghv-miR-M1-2, -4, -6, and -12 induced lytic replication by up-regulating RTA. We confirmed that the decrease in viral replication caused by mghv-miR-M1-1 was abolished by inhibition of miRNA expression via miRNA inhibitor treatment. In addition, we observed that mghv-miR-M1-1 down-regulated c-Jun indirectly and decreased cytokine production, suggesting that mghv-miR-M1-1 may inhibit MHV-68 lytic replication by inhibiting the activator protein 1 (AP-1) signaling pathway.
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Affiliation(s)
- Soowon Kang
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Korea
| | - Chanoh Jeon
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Korea
| | - Kyungtaek Im
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Korea
| | - Moon Jung Song
- Virus-Host Interactions Laboratory, Division of Biotechnology, Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, Korea.
| | - Hyeyoung Min
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Korea.
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Mitogen-Activated Protein Kinase Kinase 2, a Novel E2-Interacting Protein, Promotes the Growth of Classical Swine Fever Virus via Attenuation of the JAK-STAT Signaling Pathway. J Virol 2016; 90:10271-10283. [PMID: 27605672 PMCID: PMC5105662 DOI: 10.1128/jvi.01407-16] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 08/23/2016] [Indexed: 01/19/2023] Open
Abstract
The mitogen-activated protein kinase kinase/extracellular regulated kinase (MEK1/2/ERK1/2) cascade is involved in the replication of several members of the Flaviviridae family, including hepatitis C virus and dengue virus. The effects of the cascade on the replication of classical swine fever virus (CSFV), a fatal pestivirus of pigs, remain unknown. In this study, MEK2 was identified as a novel binding partner of the E2 protein of CSFV using yeast two-hybrid screening. The E2-MEK2 interaction was confirmed by glutathione S-transferase pulldown, coimmunoprecipitation, and laser confocal microscopy assays. The C termini of E2 (amino acids [aa] 890 to 1053) and MEK2 (aa 266 to 400) were mapped to be crucial for the interaction. Overexpression of MEK2 significantly promoted the replication of CSFV, whereas knockdown of MEK2 by lentivirus-mediated small hairpin RNAs dramatically inhibited CSFV replication. In addition, CSFV infection induced a biphasic activation of ERK1/2, the downstream signaling molecules of MEK2. Furthermore, the replication of CSFV was markedly inhibited in PK-15 cells treated with U0126, a specific inhibitor for MEK1/2/ERK1/2, whereas MEK2 did not affect CSFV replication after blocking the interferon-induced Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway by ruxolitinib, a JAK-STAT-specific inhibitor. Taken together, our results indicate that MEK2 positively regulates the replication of CSFV through inhibiting the JAK-STAT signaling pathway. IMPORTANCE Mitogen-activated protein kinase kinase 2 (MEK2) is a kinase that operates immediately upstream of extracellular regulated kinase 1/2 (ERK1/2) and links to Raf and ERK via phosphorylation. Currently, little is known about the role of MEK2 in the replication of classical swine fever virus (CSFV), a devastating porcine pestivirus. Here, we investigated the roles of MEK2 and the MEK2/ERK1/2 cascade in the growth of CSFV for the first time. We show that MEK2 positively regulates CSFV replication. Notably, we demonstrate that MEK2 promotes CSFV replication through inhibiting the interferon-induced JAK-STAT signaling pathway, a key antiviral pathway involved in innate immunity. Our work reveals a novel role of MEK2 in CSFV infection and sheds light on the molecular basis by which pestiviruses interact with the host cell.
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Lee C, Kim Y, Jeon JH. JNK and p38 mitogen-activated protein kinase pathways contribute to porcine epidemic diarrhea virus infection. Virus Res 2016; 222:1-12. [PMID: 27215486 PMCID: PMC7114560 DOI: 10.1016/j.virusres.2016.05.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/17/2016] [Accepted: 05/18/2016] [Indexed: 12/16/2022]
Abstract
PEDV infection activated p38 MAPK and JNK1/2 in vitro. UV-inactivated virus failed to induce p38 MAPK and JNK1/2 activation. Pharmacological inhibition of p38 MAPK or JNK activation impaired PEDV replication. SAPK cascades do not affect the apoptosis pathway during PEDV infection. PEDV exploits the p38 MAPK and JNK signaling pathways for optimal replication.
The mitogen-activated protein kinase (MAPK) pathways, which are central building blocks in the intracellular signaling network, are often manipulated by viruses of diverse families to favor their replication. Among the MAPK family, the extracellular signal-regulated kinase (ERK) pathway is known to be modulated during the infection with porcine epidemic diarrhea virus (PEDV); however, involvement of stress-activated protein kinases (SAPKs) comprising p38 MAPK and c-Jun NH2-terminal kinase (JNK) remains to be determined. Therefore, in the present study, we investigated whether activation of p38 MAPK and JNK cascades is required for PEDV replication. Our results showed that PEDV activates p38 MAPK and JNK1/2 up to 24 h post-infection, whereas, thereafter their phosphorylation levels recede to baseline levels or even fall below them. Notably, UV-irradiated inactivated PEDV, which can enter cells but cannot replicate inside them, failed to induce phosphorylation of p38 MAPK and JNK1/2 suggesting that viral biosynthesis is essential for activation of these kinases. Treatment of cells with selective p38 or JNK inhibitors markedly impaired PEDV replication in a dose-dependent manner and these antiviral effects were found to be maximal during the early times of the infection. Furthermore, direct pharmacological inhibition of p38 MAPK or JNK1/2 activation resulted in a significant reduction of viral RNA synthesis, viral protein expression, and progeny release. However, independent treatments with either SAPK inhibitor did not inhibit PEDV-induced apoptotic cell death mediated by activation of mitochondrial apoptosis-inducing factor (AIF) suggesting that SAPKs are irrelevant to the apoptosis pathway during PEDV infection. In summary, our data demonstrated critical roles of the p38 and JNK1/2 signaling pathways in facilitating successful viral infection during the post-entry steps of the PEDV life cycle.
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Affiliation(s)
- Changhee Lee
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea.
| | - Youngnam Kim
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Ji Hyun Jeon
- Animal Virology Laboratory, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
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Guo M, Wei J, Huang X, Zhou Y, Yan Y, Qin Q. JNK1 Derived from Orange-Spotted Grouper, Epinephelus coioides, Involving in the Evasion and Infection of Singapore Grouper Iridovirus (SGIV). Front Microbiol 2016; 7:121. [PMID: 26903999 PMCID: PMC4748057 DOI: 10.3389/fmicb.2016.00121] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/22/2015] [Indexed: 01/16/2023] Open
Abstract
c-Jun N-terminal kinase (JNK) regulates cellular responses to various extracellular stimuli, environmental stresses, pathogen infections, and apoptotic agents. Here, a JNK1, Ec-JNK1, was identified from orange-spotted grouper, Epinephelus coioides. Ec-JNK1 has been found involving in the immune response to pathogen challenges in vivo, and the infection of Singapore grouper iridovirus (SGIV) and SGIV-induced apoptosis in vitro. SGIV infection activated Ec-JNK1, of which phosphorylation of motif TPY is crucial for its activity. Over-expressing Ec-JNK1 phosphorylated transcription factors c-Jun and promoted the infection and replication of SGIV, while partial inhibition of the phosphorylation of Ec-JNK1 showed the opposite effects by over-expressing the dominant-negative EcJNK1-Δ183-185 mutant. Interestingly, SGIV enhanced the viral infectivity by activating Ec-JNK1 which in turn drastically inhibited the antiviral responses of type 1 IFN, indicating that Ec-JNK1 could be involved in blocking IFN signaling during SGIV infection. In addition, Ec-JNK1 enhanced the activation of AP-1, p53, and NF-κB, and resulted in increasing the levels of SGIV-induced cell death. The caspase 3-dependent activation correlated with the phosphorylation of Ec-JNK1 and contributed to SGIV-induced apoptosis. Taken together, SGIV modulated the phosphorylation of Ec-JNK1 to inactivate the antiviral signaling, enhance the SGIV-induced apoptosis and activate transcription factors for efficient infection and replication. The “positive cooperativity” molecular mechanism mediated by Ec-JNK1 contributes to the successful evasion and infection of iridovirus pathogenesis.
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Affiliation(s)
- Minglan Guo
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Jingguang Wei
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Xiaohong Huang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Yongcan Zhou
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University Haikou, China
| | - Yang Yan
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China
| | - Qiwei Qin
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of SciencesGuangzhou, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and TechnologyQingdao, China
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Purushothaman P, Dabral P, Gupta N, Sarkar R, Verma SC. KSHV Genome Replication and Maintenance. Front Microbiol 2016; 7:54. [PMID: 26870016 PMCID: PMC4740845 DOI: 10.3389/fmicb.2016.00054] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 01/12/2016] [Indexed: 12/04/2022] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8) is a major etiological agent for multiple severe malignancies in immune-compromised patients. KSHV establishes lifetime persistence in the infected individuals and displays two distinct life cycles, generally a prolonged passive latent, and a short productive or lytic cycle. During latent phase, the viral episome is tethered to the host chromosome and replicates once during every cell division. Latency-associated nuclear antigen (LANA) is a predominant multifunctional nuclear protein expressed during latency, which plays a central role in episome tethering, replication and perpetual segregation of the episomes during cell division. LANA binds cooperatively to LANA binding sites (LBS) within the terminal repeat (TR) region of the viral episome as well as to the cellular nucleosomal proteins to tether viral episome to the host chromosome. LANA has been shown to modulate multiple cellular signaling pathways and recruits various cellular proteins such as chromatin modifying enzymes, replication factors, transcription factors, and cellular mitotic framework to maintain a successful latent infection. Although, many other regions within the KSHV genome can initiate replication, KSHV TR is important for latent DNA replication and possible segregation of the replicated episomes. Binding of LANA to LBS favors the recruitment of various replication factors to initiate LANA dependent DNA replication. In this review, we discuss the molecular mechanisms relevant to KSHV genome replication, segregation, and maintenance of latency.
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Affiliation(s)
- Pravinkumar Purushothaman
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Prerna Dabral
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Namrata Gupta
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Roni Sarkar
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno Reno, NV, USA
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Umasuthan N, Bathige SDNK, Noh JK, Lee J. Gene structure, molecular characterization and transcriptional expression of two p38 isoforms (MAPK11 and MAPK14) from rock bream (Oplegnathus fasciatus). FISH & SHELLFISH IMMUNOLOGY 2015; 47:331-343. [PMID: 26363230 DOI: 10.1016/j.fsi.2015.09.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 09/07/2015] [Accepted: 09/07/2015] [Indexed: 06/05/2023]
Abstract
The p38 kinases are one of the four subgroups of mitogen-activated protein kinase (MAPK) superfamily which are involved in the innate immunity. The p38 subfamily that includes four members namely p38α (MAPK14), p38β (MAPK11), p38γ (MAPK12) and p38δ (MAPK13), regulates the activation of several transcription factors. In this study, a p38β (OfMAPK11) homolog and a p38α (OfMAPK14) homolog of Oplegnathus fasciatus were identified at genomic level. Results clearly showed that both MAPK11 and MAPK14 are well-conserved at both genomic structural- and amino acid (aa)-levels. Genomic sequences of OfMAPK11 (∼ 15.6 kb) and OfMAPK14 (∼ 13.4 kb) had 12 exons. A comparison of exon-intron structural arrangement of these genes from different vertebrate lineages indicated that all the exon lengths are highly conserved, except their terminal exons. Full-length cDNAs of OfMAPK11 (3957 bp) and OfMAPK14 (2504 bp) encoded corresponding proteins of 361 aa and 360 aa, respectively. Both OfMAPK proteins harbored a Ser/Thr protein kinases catalytic domain (S_TKc domain) which includes an activation loop with a dual phosphorylation site (TGY motif) and several specific-binding sites for ATP and substrates. Molecular modeling of the activation loop and substrate binding sites of rock bream MAPKs revealed the conservation of crucial residues and their orientation in 3D space. Transcripts of OfMAPKs were ubiquitously detected in eleven tissues examined, however at different levels. The modulation of OfMAPKs' transcription upon pathogen-associated molecular patterns (PAMPs: flagellin, lipopolysaccharide and poly I:C) and pathogens (Edwardsiella tarda, Streptococcus iniae and rock bream iridovirus) was investigated. Among the seven examined tissues, the flagellin-challenge upregulated the mRNA level of both OfMAPKs in the head kidney. Meanwhile, modulation of OfMAPK mRNA expression in the liver upon other immune-challenges varied in a time-dependent manner. Collectively, these results suggest that OfMAPKs are true members of p38 subfamily, which might be induced by different immune stimuli.
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Affiliation(s)
- Navaneethaiyer Umasuthan
- Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea
| | - S D N K Bathige
- Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea
| | - Jae Koo Noh
- Genetics & Breeding Research Center, National Fisheries Research & Development Institute, Geoje 656-842, Republic of Korea
| | - Jehee Lee
- Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea; Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea.
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Tan X, Gao Y, Nan Y, Zhang J, Di C, Wang X, Lian F, Cao Y, Hu Y, Xu L, Ma H, Hong Y, Liu T, Wu Y, Xu X, Yan Y, Yang L. Cellular MicroRNA Let-7a Suppresses KSHV Replication through Targeting MAP4K4 Signaling Pathways. PLoS One 2015. [PMID: 26197270 PMCID: PMC4511191 DOI: 10.1371/journal.pone.0132148] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Background Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) is the etiologic agent of KS, the most common AIDS-related malignancy. The majority of KS tumor cells harbor latent KSHV virus but only a small percentage undergoes spontaneous lytic replication. Viral reactivation from latency is crucial for the pathogenesis and development of KS, but the cellular mechanisms underlying the switch between viral latency and replication are not well understood. Methods The level of let-7 miRNAs and MAP4K4 in KSHV infected 293T cells were quantified by real-time PCRs. Let-7 expression was silenced by the miRNA sponge technique. In let-7a transfected 293T cells, the expression of MAP4K4 was measured by real-time PCR and western blot. Luciferease expression was employed to examine the effect of let-7a on the 3’-untranslated region (UTR) of the MAP4K4 gene in 293T cells. Real-time PCR was used to quantify the KSHV copy numbers in BC-3 cells in which the expression of let-7a and/or MAP4K4 were altered. Finally, ERK, JNK and p38 protein production and their phosphorylation status were detected by western blots in let-7a or MAP4K4 transfected BCBL-1 cells. Results The expression of microRNA let-7 was dramatically decreased in KSHV infected 293T cells, but that of MAP4K4 was increased significantly. Let-7a is physically associated with and targets the MAP4K4 3’UTR, and inhibits MAP4K4 expression at both mRNA and protein levels. MAP4K4 stimulates KSHV reactivation from latency, whereas let-7a inhibits the function of MAP4K4 by reversing the function of MAP4K4 on JNK, phospho-JNK and phospho-ERK1/2 levels. Conclusion Our results establish that let-7a specifically suppresses MAP4K4 expression, and further inhibits KSHV reactivation by interfering with the function of MAP4K4 on the MAPK pathway, highlighting let-7a as a potential treatment for KS.
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Affiliation(s)
- Xiaohua Tan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yuan Gao
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yulong Nan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Jinxia Zhang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Chunhong Di
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xiaobo Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Fuzhi Lian
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yifei Cao
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yu Hu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Liangwen Xu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Haiyan Ma
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yu Hong
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Tingjie Liu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yinyin Wu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Xianrong Xu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Yutao Yan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Lei Yang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
- * E-mail:
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Screening of the Human Kinome Identifies MSK1/2-CREB1 as an Essential Pathway Mediating Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication during Primary Infection. J Virol 2015; 89:9262-80. [PMID: 26109721 DOI: 10.1128/jvi.01098-15] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 06/21/2015] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED Viruses often hijack cellular pathways to facilitate infection and replication. Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic gammaherpesvirus etiologically associated with Kaposi's sarcoma, a vascular tumor of endothelial cells. Despite intensive studies, cellular pathways mediating KSHV infection and replication are still not well defined. Using an antibody array approach, we examined cellular proteins phosphorylated during primary KSHV infection of primary human umbilical vein endothelial cells. Enrichment analysis identified integrin/mitogen-activated protein kinase (integrin/MAPK), insulin/epidermal growth factor receptor (insulin/EGFR), and JAK/STAT as the activated networks during primary KSHV infection. The transcriptional factor CREB1 (cyclic AMP [cAMP]-responsive element-binding protein 1) had the strongest increase in phosphorylation. While knockdown of CREB1 had no effect on KSHV entry and trafficking, it drastically reduced the expression of lytic transcripts and proteins and the production of infectious virions. Chemical activation of CREB1 significantly enhanced viral lytic replication. In contrast, CREB1 neither influenced the expression of the latent gene LANA nor affected KSHV infectivity. Mechanistically, CREB1 was not activated through the classic cAMP/protein kinase A (cAMP/PKA) pathway or via the AKT, MK2, and RSK pathways. Rather, CREB1 was activated by the mitogen- and stress-activated protein kinases 1 and 2 (MSK1/2). Consequently, chemical inhibition or knockdown of MSKs significantly inhibited the KSHV lytic replication program; however, it had a minimal effect on LANA expression and KSHV infectivity. Together, these results identify the MSK1/2-CREB1 proteins as novel essential effectors of KSHV lytic replication during primary infection. The differential effect of the MSK1/2-CREB1 pathway on the expression of viral latent and lytic genes might control the robustness of viral lytic replication, and therefore the KSHV replication program, during primary infection. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) is a human tumor virus associated with several cancers. Through genome-wide kinase screening, we found that KSHV activates the MSK1/2-CREB1 pathway during primary infection and that it depends on this pathway for viral lytic replication. Inhibition of this pathway blocks KSHV lytic replication. These results illustrate a mechanism by which KSHV hijacks a cellular pathway for its replication, and they identify a potential therapeutic target.
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Boulant S, Stanifer M, Lozach PY. Dynamics of virus-receptor interactions in virus binding, signaling, and endocytosis. Viruses 2015; 7:2794-815. [PMID: 26043381 PMCID: PMC4488714 DOI: 10.3390/v7062747] [Citation(s) in RCA: 125] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 02/06/2023] Open
Abstract
During viral infection the first challenge that viruses have to overcome is gaining access to the intracellular compartment. The infection process starts when the virus contacts the surface of the host cell. A complex series of events ensues, including diffusion at the host cell membrane surface, binding to receptors, signaling, internalization, and delivery of the genetic information. The focus of this review is on the very initial steps of virus entry, from receptor binding to particle uptake into the host cell. We will discuss how viruses find their receptor, move to sub-membranous regions permissive for entry, and how they hijack the receptor-mediated signaling pathway to promote their internalization.
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Affiliation(s)
- Steeve Boulant
- CellNetworks-Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany.
- Schaller research group at CellNetworks and DKFZ (German cancer research center), 69120 Heidelberg, Germany.
| | - Megan Stanifer
- CellNetworks-Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany.
- Schaller research group at CellNetworks and DKFZ (German cancer research center), 69120 Heidelberg, Germany.
| | - Pierre-Yves Lozach
- CellNetworks-Cluster of Excellence and Department of Infectious Diseases, Virology, University Hospital Heidelberg, 69120 Heidelberg, Germany.
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44
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Celecoxib Inhibits the Lytic Activation of Kaposi's Sarcoma-Associated Herpesvirus through Down-Regulation of RTA Expression by Inhibiting the Activation of p38 MAPK. Viruses 2015; 7:2268-87. [PMID: 25951487 PMCID: PMC4452905 DOI: 10.3390/v7052268] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 04/09/2015] [Accepted: 04/28/2015] [Indexed: 12/19/2022] Open
Abstract
Kaposi’s sarcoma associated herpesvirus (KSHV) is the etiologic agent of Kaposi’s sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman’s disease (MCD). KSHV’s lytic replication cycle is critical for the pathogenesis of KSHV-associated diseases. Despite recent progress in the development of treatments for KSHV associated malignancies, these therapies are not completely efficacious and cause side effects. Therefore, more effective therapies with antiviral agents against KSHV are urgently needed. In this study, we identified celecoxib as an antiviral agent against KSHV. Our data suggest that celecoxib inhibits the lytic activation of KSHV through the down-regulation of the expression of the lytic switch protein, replication and transcription activator (RTA), by inhibiting the activation of p38 MAPK. Therefore, celecoxib may provide a candidate inhibitor for the therapeutic research of KSHV-related malignancies.
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45
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ORF45-Mediated Prolonged c-Fos Accumulation Accelerates Viral Transcription during the Late Stage of Lytic Replication of Kaposi's Sarcoma-Associated Herpesvirus. J Virol 2015; 89:6895-906. [PMID: 25903346 DOI: 10.1128/jvi.00274-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/15/2015] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) encodes multiple viral proteins that activate extracellular signal-regulated kinase (ERK)-mitogen-activated protein kinase (MAPK) cascades. One of these viral proteins, ORF45, mediates sustained ERK-p90 ribosomal S6 kinase (RSK) activation during KSHV lytic replication and facilitates viral translation through the phosphorylation of a eukaryotic translation initiation factor, eIF4B. The importance of ERK-RSK activation for KSHV viral transcription has been shown; however, which transcription factor senses the sustained MAPK signaling and leads to viral transcription remains poorly understood. Here we show that the presence of ORF45 leads to the prolonged accumulation of c-Fos during the late stage of KSHV lytic replication through ERK-RSK-dependent phosphorylation and stabilization and that the depletion of c-Fos disrupts viral lytic transcription. Genome-wide screening revealed that c-Fos directly binds to multiple viral gene promoters and enhances viral transcription. Mutation of the ERK-RSK phosphorylation sites of c-Fos restrains KSHV lytic gene expression and virion production. These results indicate that the prolonged accumulation of c-Fos promotes the progression of viral transcription from early to late stages and accelerates viral lytic replication upon sustained ORF45-ERK-RSK activation during the KSHV lytic life cycle. IMPORTANCE During KSHV lytic replication, transient activation and sustained activation of ERK-RSK induce viral immediate early (IE) transcription and late transcription, respectively. Studies have revealed that ERK-RSK activates several transcription factors involved in IE gene expression, including Ets, AP-1, CREB, and C/EBP, which lead to the transient ERK-RSK activation-dependent IE transcription. Whereas c-Fos acts as a sensor of sustained ERK-RSK activation, ORF45-ERK-RSK signaling mediates c-Fos phosphorylation and accumulation during late KSHV lytic replication, consequently promoting viral transcription through the direct binding of c-Fos to multiple KSHV promoters. This finding indicates that c-Fos mediates distinct viral transcriptional progression following sustained ERK-RSK signaling during the KSHV lytic life cycle.
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Abstract
Kaposi’s sarcoma-associated herpesvirus (KSHV) primarily persists as a latent episome in infected cells. During latent infection, only a limited number of viral genes are expressed that help to maintain the viral episome and prevent lytic reactivation. The latent KSHV genome persists as a highly ordered chromatin structure with bivalent chromatin marks at the promoter-regulatory region of the major immediate-early gene promoter. Various stimuli can induce chromatin modifications to an active euchromatic epigenetic mark, leading to the expression of genes required for the transition from the latent to the lytic phase of KSHV life cycle. Enhanced replication and transcription activator (RTA) gene expression triggers a cascade of events, resulting in the modulation of various cellular pathways to support viral DNA synthesis. RTA also binds to the origin of lytic DNA replication to recruit viral, as well as cellular, proteins for the initiation of the lytic DNA replication of KSHV. In this review we will discuss some of the pivotal genetic and epigenetic factors that control KSHV reactivation from the transcriptionally restricted latent program.
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EBV microRNA BART 18-5p targets MAP3K2 to facilitate persistence in vivo by inhibiting viral replication in B cells. Proc Natl Acad Sci U S A 2014; 111:11157-62. [PMID: 25012295 DOI: 10.1073/pnas.1406136111] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
EBV is an oncogenic human herpesvirus that has the ability to infect and transform B cells latently in vitro. However, the virus also establishes a lifetime, benign, persistent latent infection in resting memory B cells in vivo, where the virus is quiescent (i.e., expresses none of the known latent proteins). The virus encodes ∼40 micro-RNAs (miRNAs), most of which are transcribed from the BamH1 fragment A rightward transcript (BART) region of the virus. We have shown previously that a subset of these miRNAs is present at high copy numbers in latently infected memory B cells in vivo, suggesting a role in maintaining latency. Here, we describe the role of one of these miRNAs, BART 18-5p. We show that it targets the 3'UTR of the mRNA, encoding the important cellular signaling molecule MAP kinase kinase kinase 2 (MAP3K2), at exactly the same site as the oncogenic cellular miRNA mir-26a-5p. To our knowledge, this is the first report of a virus encoding a miRNA that suppresses a target in the MAP kinase signaling cascade, a central signal transduction pathway that governs a broad spectrum of biological processes. We further show that MAP3K2 is an intermediary in the signaling pathways that initiate lytic viral replication. Thus, 18-5p expression in latently infected B cells has the effect of blocking viral replication. We propose that the role of 18-5p is to maintain latency by reducing the risk of fortuitous reactivation of the virus in latently infected memory B cells.
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48
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Johnson JC, Martinez O, Honko AN, Hensley LE, Olinger GG, Basler CF. Pyridinyl imidazole inhibitors of p38 MAP kinase impair viral entry and reduce cytokine induction by Zaire ebolavirus in human dendritic cells. Antiviral Res 2014; 107:102-9. [PMID: 24815087 DOI: 10.1016/j.antiviral.2014.04.014] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 01/03/2023]
Abstract
Antigen presenting cells (APCs), including macrophages and dendritic cells, are early and sustained targets of Ebola virus (EBOV) infection in vivo. Because EBOV activates mitogen-activated protein kinase (MAPK) signaling upon infection of APCs, we evaluated the effect of pyridinyl imidazole inhibitors of p38 MAPK on EBOV infection of human APCs and EBOV mediated cytokine production from human DCs. The p38 MAPK inhibitors reduced viral replication in PMA-differentiated macrophage-like human THP-1 cells with an IC50 of 4.73μM (SB202190), 8.26μM (p38kinhIII) and 8.21μM (SB203580) and primary human monocyte-derived dendritic cells (MDDCs) with an IC50 of 2.67μM (SB202190). Furthermore, cytokine production from EBOV-treated MDDCs was inhibited in a dose-dependent manner. A control pyridinyl imidazole compound failed to inhibit either EBOV infection or cytokine induction. Using an established EBOV virus-like particle (VLP) entry assay, we demonstrate that inhibitor pretreatment blocked VLP entry suggesting that the inhibitors blocked infection and replication at least in part by blocking EBOV entry. Taken together, our results indicate that pyridinyl imidazole p38 MAPK inhibitors may serve as leads for the development of therapeutics to treat EBOV infection.
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Affiliation(s)
- Joshua C Johnson
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702, United States
| | - Osvaldo Martinez
- Dept. of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States
| | - Anna N Honko
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702, United States
| | - Lisa E Hensley
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702, United States
| | - Gene G Olinger
- Virology Division, United States Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702, United States
| | - Christopher F Basler
- Dept. of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States.
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Woodson EN, Anderson MS, Loftus MS, Kedes DH. Progressive accumulation of activated ERK2 within highly stable ORF45-containing nuclear complexes promotes lytic gammaherpesvirus infection. PLoS Pathog 2014; 10:e1004066. [PMID: 24722398 PMCID: PMC3983062 DOI: 10.1371/journal.ppat.1004066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 02/27/2014] [Indexed: 11/19/2022] Open
Abstract
De novo infection with the gammaherpesvirus Rhesus monkey rhadinovirus (RRV), a close homolog of the human oncogenic pathogen, Kaposi's sarcoma-associated herpesvirus (KSHV), led to persistent activation of the MEK/ERK pathway and increasing nuclear accumulation of pERK2 complexed with the RRV protein, ORF45 (R45) and cellular RSK. We have previously shown that both lytic gene expression and virion production are dependent on the activation of ERK [1]. Using confocal microscopy, sequential pull-down assays and FRET analyses, we have demonstrated that pERK2-R45-RSK2 complexes were restricted to the nucleus but that the activated ERK retained its ability to phosphorylate nuclear substrates throughout infection. Furthermore, even with pharmacologic inhibition of MEK beginning at 48 h p.i., pERK2 but not pERK1, remained elevated for at least 10 h, showing first order decay and a half-life of nearly 3 hours. Transfection of rhesus fibroblasts with R45 alone also led to the accumulation of nuclear pERK2 and addition of exogenous RSK augmented this effect. However, knock down of RSK during bona fide RRV infection had little to no effect on pERK2 accumulation or virion production. The cytoplasmic pools of pERK showed no co-localization with either RSK or R45 but activation of pERK downstream targets in this compartment was evident throughout infection. Together, these observations suggest a model in which R45 interacts with pERK2 to promote its nuclear accumulation, thereby promoting lytic viral gene expression while also preserving persistent and robust activation of both nuclear and cytoplasmic ERK targets.
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Affiliation(s)
- Evonne N. Woodson
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Melissa S. Anderson
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Matthew S. Loftus
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Dean H. Kedes
- Myles H. Thaler Center for AIDS and Human Retrovirus Research, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Internal Medicine, Division of Infectious Diseases and International Health, University of Virginia Health Systems, Charlottesville, Virginia, United States of America
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Bandyopadhyay C, Valiya-Veettil M, Dutta D, Chakraborty S, Chandran B. CIB1 synergizes with EphrinA2 to regulate Kaposi's sarcoma-associated herpesvirus macropinocytic entry in human microvascular dermal endothelial cells. PLoS Pathog 2014; 10:e1003941. [PMID: 24550731 PMCID: PMC3923796 DOI: 10.1371/journal.ppat.1003941] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 01/08/2014] [Indexed: 11/19/2022] Open
Abstract
KSHV envelope glycoproteins interact with cell surface heparan sulfate and integrins, and activate FAK, Src, PI3-K, c-Cbl, and Rho-GTPase signal molecules in human microvascular dermal endothelial (HMVEC-d) cells. c-Cbl mediates the translocation of virus bound α3β1 and αVβ3 integrins into lipid rafts (LRs), where KSHV interacts and activates EphrinA2 (EphA2). EphA2 associates with c-Cbl-myosin IIA and augmented KSHV-induced Src and PI3-K signals in LRs, leading to bleb formation and macropinocytosis of KSHV. To identify the factor(s) coordinating the EphA2-signal complex, the role of CIB1 (calcium and integrin binding protein-1) associated with integrin signaling was analyzed. CIB1 knockdown did not affect KSHV binding to HMVEC-d cells but significantly reduced its entry and gene expression. In contrast, CIB1 overexpression increased KSHV entry in 293 cells. Single virus particle infection and trafficking during HMVEC-d cell entry was examined by utilizing DiI (envelope) and BrdU (viral DNA) labeled virus. CIB1 was associated with KSHV in membrane blebs and in Rab5 positive macropinocytic vesicles. CIB1 knockdown abrogated virus induced blebs, macropinocytosis and virus association with the Rab5 macropinosome. Infection increased the association of CIB1 with LRs, and CIB1 was associated with EphA2 and KSHV entry associated signal molecules such as Src, PI3-K, and c-Cbl. CIB1 knockdown significantly reduced the infection induced EphA2, Src and Erk1/2 activation. Mass spectrometry revealed the simultaneous association of CIB1 and EphA2 with the actin cytoskeleton modulating myosin IIA and alpha-actinin 4 molecules, and CIB1 knockdown reduced EphA2's association with myosin IIA and alpha-actinin 4. Collectively, these studies revealed for the first time that CIB1 plays a role in virus entry and macropinocytosis, and suggested that KSHV utilizes CIB1 as one of the key molecule(s) to coordinate and sustain the EphA2 mediated signaling involved in its entry, and CIB1 is an attractive therapeutic target to block KSHV infection.
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Affiliation(s)
- Chirosree Bandyopadhyay
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Mohanan Valiya-Veettil
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Dipanjan Dutta
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Sayan Chakraborty
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Bala Chandran
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
- * E-mail:
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