1
|
Herbein G. Cellular Transformation by Human Cytomegalovirus. Cancers (Basel) 2024; 16:1970. [PMID: 38893091 PMCID: PMC11171319 DOI: 10.3390/cancers16111970] [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: 03/16/2024] [Revised: 05/13/2024] [Accepted: 05/17/2024] [Indexed: 06/21/2024] Open
Abstract
Epstein-Barr virus (EBV), Kaposi sarcoma human virus (KSHV), human papillomavirus (HPV), hepatitis B and C viruses (HBV, HCV), human T-lymphotropic virus-1 (HTLV-1), and Merkel cell polyomavirus (MCPyV) are the seven human oncoviruses reported so far. While traditionally viewed as a benign virus causing mild symptoms in healthy individuals, human cytomegalovirus (HCMV) has been recently implicated in the pathogenesis of various cancers, spanning a wide range of tissue types and malignancies. This perspective article defines the biological criteria that characterize the oncogenic role of HCMV and based on new findings underlines a critical role for HCMV in cellular transformation and modeling the tumor microenvironment as already reported for the other human oncoviruses.
Collapse
Affiliation(s)
- Georges Herbein
- Department Pathogens & Inflammation-EPILAB EA4266, University of Franche-Comté (UFC), 25000 Besançon, France;
- Department of Virology, CHU Besançon, 25000 Besançon, France
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Jo HW, Kim MM. β-Caryophyllene oxide inhibits metastasis by downregulating MMP-2, p-p38 and p-ERK in human fibrosarcoma cells. J Food Biochem 2022; 46:e14468. [PMID: 36190169 DOI: 10.1111/jfbc.14468] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/17/2022] [Accepted: 09/23/2022] [Indexed: 01/14/2023]
Abstract
When cancer cells transform into malignant tumors, they gain the ability to ignore growth-inhibiting signals, have endless reproduction potential, resist apoptosis, and induce angiogenesis and invade other tissues. Matrix metalloproteinases (MMPs) allow tumor cells to move into surrounding tissues in many malignancies, but metastasis is blocked by MMPs inhibitors. Therefore, the effect of β-caryophyllene oxide (CPO) contained in Piper nigrum on Mitogen-activated protein kinase (MAPKs) related to MMPs signaling pathways in human fibrosarcoma was examined in HT1080 cells. The effect of CPO on cell viability was performed using the MTT assay. Cytotoxicity was observed in the presence of CPO above 16 μM. Next, gelatin zymography was performed in the cells activated with phorbol-12-myristate-13-acetate (PMA). It was found that CPO at 32 μM reduced MMP-9 activity by 28% and MMP-2 activity by 60%. To confirm the effect of CPO on MMPs, Western blot analyses for MMP-2, MAPKs were carried out in this study. The expression level of MMP-2 was reduced by 45% in the presence of CPO at 32 μM, but those of p-p38 and p-ERK were reduced by 50% and 40%, respectively. CPO decreased the expression levels of MMP-2 and MMP-9 in the immunofluorescence staining assay. Finally, an invasion assay was performed in PMA-treated human fibrosarcoma cells. It was demonstrated that CPO reduced cell invasion of HT1080 cells in a dose-dependent manner starting at a concentration of 2 μM. The above results suggest that CPO could be used as a potential candidate for the treatment of metastasis by inhibiting MMP-2, p-p38 and p-ERK. PRACTICAL APPLICATIONS: Cancer makes it easier for cells to spread to other tissue via blood and lymph systems. Tumor cells deplete nutrients and induce angiogenesis, which penetrates and spreads to other parts of the body. As a result, the effect of CPO against cell invasion was evaluated in this study. CPO reduced cancer cell invasion by inactivating p-ERK and p-p38, according to the findings. MMP-2 and MMP-9 activation and protein expression were also decreased by CPO. As a result, CPO might be used as an alternate treatment agent for preventing metastasis.
Collapse
Affiliation(s)
- Hyun Woo Jo
- Department of Applied Chemistry, Dong-Eui University, Busan, Republic of Korea.,Department of Food Science and Technology, Dong-Eui University, Busan, Republic of Korea
| | - Moon-Moo Kim
- Department of Applied Chemistry, Dong-Eui University, Busan, Republic of Korea
| |
Collapse
|
5
|
Zhang H, Wong JP, Ni G, Cano P, Dittmer DP, Damania B. Mitochondrial protein, TBRG4, modulates KSHV and EBV reactivation from latency. PLoS Pathog 2022; 18:e1010990. [PMID: 36417478 PMCID: PMC9683600 DOI: 10.1371/journal.ppat.1010990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 11/08/2022] [Indexed: 11/24/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr (EBV) are gammaherpesviruses associated with multiple human malignancies. KSHV is the etiological agent of Kaposi's Sarcoma, primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD). EBV is associated with Burkitt's lymphoma (BL), Hodgkin's lymphoma (HL), nasopharyngeal carcinoma (NPC) and gastric carcinoma (GC). KSHV and EBV establish life-long latency in the human host with intermittent periods of lytic reactivation. Here, we identified a cellular factor named transforming growth factor-beta regulator 4 (TBRG4) that plays a role in the gammaherpesvirus lifecycle. We find that TBRG4, a protein that is localized to the mitochondria, can regulate lytic reactivation from latency of both KSHV and EBV. Knockdown of TBRG4 in cells latently infected with KSHV or EBV induced viral lytic gene transcription and replication. TBRG4 deficiency causes mitochondrial stress and increases reactive oxygen species (ROS) production. Treatment with a ROS scavenger decreased viral reactivation from latency in TBRG4-depleted cells. These data suggest that TBRG4 serves as a cellular repressor of KSHV and EBV reactivation through the regulation of ROS production.
Collapse
Affiliation(s)
- Huirong Zhang
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jason P. Wong
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Guoxin Ni
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Patricio Cano
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Dirk P. Dittmer
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Blossom Damania
- Department of Microbiology and Immunology and Lineberger Comprehensive Cancer Center, and Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| |
Collapse
|
6
|
Combs LR, Spires LM, Alonso JD, Papp B, Toth Z. KSHV RTA Induces Degradation of the Host Transcription Repressor ID2 To Promote the Viral Lytic Cycle. J Virol 2022; 96:e0010122. [PMID: 35604218 PMCID: PMC9215225 DOI: 10.1128/jvi.00101-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 05/05/2022] [Indexed: 11/20/2022] Open
Abstract
The immediate early viral protein replication and transcription activator (RTA) of Kaposi's sarcoma-associated herpesvirus (KSHV) is essential for activating the lytic cycle of KSHV. RTA induces the KSHV lytic cycle by several mechanisms, acting as a viral transcription factor that directly induces viral and host genes and acting as a viral E3 ubiquitin ligase by degrading host proteins that block viral lytic replication. Recently, we have characterized the global gene expression changes in primary effusion lymphoma (PEL) upon lytic reactivation of KSHV, which also led to the identification of rapidly downregulated genes such as ID2, an inhibitor of basic helix-loop-helix transcription factors. Here, we demonstrate that ID2 overexpression in PEL ablates KSHV lytic reactivation, indicating that ID2 inhibits the KSHV lytic cycle. Furthermore, we show that while ID2 is highly expressed during latency, its protein level is rapidly reduced by 4 h postinduction during lytic reactivation. Our results indicate that RTA binds to ID2 and induces its degradation during the KSHV lytic cycle by N-terminal ubiquitination through the ubiquitin-proteasome pathway. Importantly, we found that not only KSHV RTA but also its Epstein-Barr virus (EBV) and murine gammaherpesvirus 68 (MHV68) homologs interact with ID2, and they can induce the degradation of all four members of the ID protein family, suggesting an evolutionarily conserved interplay between gammaherpesvirus RTAs and ID proteins. Taken together, we propose that ID2 acts as a repressor of the KSHV lytic cycle, which is counteracted by its RTA-mediated degradation. We also predict that ID proteins may act as restriction factors of the lytic phase of the other gammaherpesviruses as well. IMPORTANCE In addition to its transcription regulatory role, RTA is also known to have an E3 ubiquitin ligase activity, which RTA utilizes for inducing protein degradation. However, it is still largely unknown what host factors are downregulated during KSHV lytic reactivation by RTA-mediated protein degradation and what the biological significance of the degradation of these host factors is. In this study, we discovered that RTA employs N-terminal ubiquitination to induce degradation of ID2, a potent transcription repressor of host genes, via the ubiquitin-proteasome pathway to promote KSHV lytic reactivation in PEL cells. Furthermore, we found that not only KSHV RTA but also RTA of EBV and MHV68 gammaherpesviruses can induce the degradation of all four human ID proteins, indicating that the interplay between gammaherpesvirus RTAs and ID proteins is evolutionarily conserved.
Collapse
Affiliation(s)
- Lauren R. Combs
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Lauren McKenzie Spires
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Juan D. Alonso
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Bernadett Papp
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
- University of Florida Genetics Institute, Gainesville, Florida, USA
- University of Florida Health Cancer Center, Gainesville, Florida, USA
- University of Florida Center for Orphaned Autoimmune Disorders, Gainesville, Florida, USA
- University of Florida Informatics Institute, Gainesville, Florida, USA
| | - Zsolt Toth
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
- University of Florida Genetics Institute, Gainesville, Florida, USA
- University of Florida Health Cancer Center, Gainesville, Florida, USA
| |
Collapse
|
7
|
Wu S, Wu Z, Xu H, Zhang J, Gu W, Tan X, Pan Z, Cao D, Li D, Yang L, Li D, Pan Y. miR-34a-5p inhibits the malignant progression of KSHV-infected SH-SY5Y cells by targeting c-fos. PeerJ 2022; 10:e13233. [PMID: 35444864 PMCID: PMC9014853 DOI: 10.7717/peerj.13233] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 03/17/2022] [Indexed: 01/15/2023] Open
Abstract
Background We aimed to investigate the effects of miR-34a-5p on c-fos regulation mediating the malignant behaviors of SH-SY5Y cells infected with Kaposi's sarcoma-associated herpesvirus (KSHV). Methods The KSHV-infected (SK-RG) and uninfected SH-SY5Y parent cells were compared for differentially expressed miRNAs using transcriptome sequencing. Then miR-34a-5p was upregulated in SK-RG cells by the miRNA mimics transfection. Cell proliferation ability was determined by MTT and plate clone assays. The cell cycle was assessed by flow cytometry analysis, and CDK4, CDK6, cyclin D1 levels were determined by Western blot analysis. The migration behavior was detected by wound healing and transwell assays. The protein levels of MMP2 and MMP9 were measured by Western blot analysis. The regulation of c-fos by miR-34a-5p was detected by the dual-luciferase reporter gene assay. Rescue assays were carried out by upregulating c-fos in miR-34a-5p-overexpressing SK-RG cells. KSHV DNA copy numbers and relative virus gene expressions were detected. Xenograft tumor experiments and immunohistochemistry assays were further used to detect the effects of miR-34a-5p. Results miR-34a-5p was lower in SK-RG cells. Restoration of miR-34a-5p decreased cell proliferation and migration, leading to a G1 cell cycle arrest and down-regulation of CDK4/6, cyclin D1, MMP2, MMP9. KSHV copy number and expression of virus gene including latency-associated nuclear antigen (LANA), replication and transcription activator (RTA), open reading frame (K8.1), and KSHV G protein-coupled receptor (v-GPCR) were also reduced. Furthermore, c-fos is the target of miR-34a-5p, while enhanced c-fos weakened cellular behaviors of miR-34a-5p-overexpressing cells. Xenograft experiments and immunohistochemistry assays showed that miR-34a-5p inhibited tumor growth and virus gene expression. Conclusion Upregulated miR-34a-5p in KSHV-infected SH-SY5Y cells suppressed cell proliferation and migration through down-regulating c-fos. miR-34a-5p was a candidate molecular drug for KSHV-infected neuronal cells.
Collapse
Affiliation(s)
- Shuyuan Wu
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Zhaofu Wu
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Huiling Xu
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Jinli Zhang
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Wenyi Gu
- Australian Institute for Bioengineering and Nanotechnology (AIBN), University of Queensland (UQ), St Lucia, Brisbane, Australia
| | - Xiaohua Tan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Zemin Pan
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Dongdong Cao
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Dongmei Li
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Lei Yang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, China
| | - Dongmei Li
- Key Laboratory of Xinjiang Endemic and Ethnic Diseases/NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, School of Medicine, Shihezi University, Shihezi, Xinjiang, China
| | - Yuanming Pan
- Department of Cellular and Molecular Biology, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, Beijing, China
| |
Collapse
|
8
|
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.
Collapse
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,
| |
Collapse
|
9
|
Viruses and Skin Cancer. Int J Mol Sci 2021; 22:ijms22105399. [PMID: 34065594 PMCID: PMC8161099 DOI: 10.3390/ijms22105399] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 12/11/2022] Open
Abstract
Advances in virology and skin cancer over recent decades have produced achievements that have been recognized not only in the field of dermatology, but also in other areas of medicine. They have modified the therapeutic and preventive solutions that can be offered to some patients and represent a significant step forward in our knowledge of the biology of skin cancer. In this paper, we review the viral agents responsible for different types of skin cancer, especially for solid skin tumors. We focus on human papillomavirus and squamous cell cancers, Merkel cell polyomavirus and Merkel cell carcinoma, and human herpesvirus 8 and Kaposi’s sarcoma.
Collapse
|
10
|
KDM2B Overexpression Facilitates Lytic De Novo KSHV Infection by Inducing AP-1 Activity Through Interaction with the SCF E3 Ubiquitin Ligase Complex. J Virol 2021; 95:JVI.00331-21. [PMID: 33692209 PMCID: PMC8139688 DOI: 10.1128/jvi.00331-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
It is still largely unknown what host factors are involved in controlling the expression of the lytic viral gene RTA during primary infection, which determines if Kaposi's sarcoma-associated herpesvirus (KSHV) establishes latent or lytic infection. We have recently identified the histone demethylase KDM2B as a repressor of RTA expression during both de novo KSHV infection and latency based on an epigenetic factor siRNA screen. Here, we report that surprisingly, KDM2B overexpression can promote lytic de novo infection by using a mechanism that differs from what is needed for its repressor function. Our study revealed that while the DNA-binding and demethylase activities of KDM2B linked to its transcription repressive function are dispensable, its C-terminal F-box and LRR domains are required for the lytic infection-inducing function of KDM2B. We found that overexpressed KDM2B increases the half-life of the AP-1 subunit c-Jun protein and induces the AP-1 signaling pathway. This effect is dependent upon the binding of KDM2B to the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase complex via its F-box domain. Importantly, the inhibition of AP-1 reduces KDM2B-mediated lytic de novo KSHV infection. Overall, our findings indicate that KDM2B may induce the degradation of some host factors by using the SCF complex resulting in the enrichment of c-Jun. This leads to increased AP-1 transcriptional activity, which facilitates lytic gene expression following de novo infection interfering with the establishment of viral latency.SignificanceThe expression of epigenetic factors is often dysregulated in cancers or upon specific stress signals, which often results in a display of non-canonical functions of the epigenetic factors that are independent from their chromatin-modifying roles. We have previously demonstrated that KDM2B normally inhibits KSHV lytic cycle using its histone demethylase activity. Surprisingly, we found that KDM2B overexpression can promote lytic de novo infection, which does not require its histone demethylase or DNA-binding functions. Instead, KDM2B uses the SKP1-CUL1-F-box (SCF) E3 ubiquitin ligase complex to induce AP-1 transcriptional activity, which promotes lytic gene expression. This is the first report that demonstrates a functional link between SFCKDM2B and AP-1 in the regulation of KSHV lytic cycle.
Collapse
|
11
|
Yao Y, Liu W, Gajendran B, Wang C, Zacksenhaus E, Sample KM, Varier KM, Hao X, Ben-David Y. Ubash3b promotes TPA-mediated suppression of leukemogenesis through accelerated downregulation of PKCδ protein. Biochimie 2021; 184:8-17. [PMID: 33556471 DOI: 10.1016/j.biochi.2021.02.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 12/14/2020] [Accepted: 02/01/2021] [Indexed: 12/29/2022]
Abstract
Acquired drug-resistance, often involving downregulation or mutations in the target protein, is a major caveat in precision medicine. Understanding mechanisms of resistance to therapeutic drugs may unravel strategies to overcome or prevent them. We previously identified phorbol ester (PE) compounds such as TPA that induce Protein Kinase δ (PKCδ), thereby suppressing leukemogenesis. Here we identified erythroleukemia cell lines that resist PEs and showed that reduced PKCδ protein expression underlies drug resistance. Reduced level of PKCδ in resistant cell lines was due to its phosphorylation followed by protein degradation. Indeed, proteasome inhibition prevented PE-induced loss of PKCδ. Accordingly, a combination of TPA and the proteasome inhibitor ALLN significantly suppressed leukemia in a mouse model of leukemia. PKCδ downregulation by TPA was independent of the downstream MAPK/ERK/P38/JNK pathway. Instead, expression of ubiquitin-associated and SH3 domain-containing protein b (Ubash3b) was induced by TPA, which leads to PKCδ protein dephosphorylation and degradation. This specific degradation was blocked by RNAi-mediated depletion of Ubash3b. In drug-sensitive leukemic cells, TPA did not induce Ubash3b, and consequently, PKCδ levels remained high. A PE-resistant cell line derived from PE-treated sensitive cells exhibited very low PKCδ expression. In these drug resistance cells, a Ubash3b independent mechanism led to PKCδ degradation. Thus, PE compounds in combination with proteasome or specific inhibitors for Ubash3b, or other factors can overcome resistance to TPA, leading to durable suppression of leukemic growth. These results identify Ubash3b as a potential target for drug development.
Collapse
Affiliation(s)
- Yao Yao
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Wuling Liu
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Babu Gajendran
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Chunlin Wang
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Eldad Zacksenhaus
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Division of Advanced Diagnostics, Toronto General Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Klarke M Sample
- The National Health Commission's Key Laboratory of Immunological Pulmonary Disease, Guizhou Provincial People's Hospital, The Affiliated Hospital of Guizhou University, Guiyang, Guizhou, 550002, PR China
| | - Krishnapriya M Varier
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Xiaojiang Hao
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China
| | - Yaacov Ben-David
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550014, PR China; The Key Laboratory of Chemistry for Natural Products of Guizhou Province and Chinese Academic of Sciences, Guiyang, Guizhou, 550014, PR China.
| |
Collapse
|
12
|
Evaluation of Cyprinid Herpesvirus 2 Latency and Reactivation in Carassius gibel. Microorganisms 2020; 8:microorganisms8030445. [PMID: 32245260 PMCID: PMC7143840 DOI: 10.3390/microorganisms8030445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/08/2020] [Accepted: 03/19/2020] [Indexed: 12/17/2022] Open
Abstract
Cyprinid herpesvirus 2 (CyHV-2, species Cyprinid herpesvirus 2) causes severe mortality in ornamental goldfish, crucian carp (Carassius auratus), and gibel carp (Carassius gibelio). It has been shown that the genomic DNA of CyHV-2 could be detected in subclinical fish, which implied that CyHV-2 could establish persistent infection. In this study, the latency of CyHV-2 was investigated in the survival fish after primary infection. CyHV-2 genomic DNA was detected in multiple tissues of acute infection samples; however, detection of CyHV-2 DNA was significantly reduced in fish recovered from the primary infection on day 300 postinfection. No active viral gene transcription, such as DNA polymerase and ORF99, was detected in recovered fish. Following temperature stress, an increase of CyHV-2 DNA copy numbers and gene transcription were observed in tissues examined, which suggests that CyHV-2 was reactivated under stress. In addition, a cell line (GCBLat1) derived from the brain tissue from CyHV-2-exposed fish harbored CyHV-2 genome but did not produce infectious virions under normal culture conditions. However, CyHV-2 replication and viral gene transcription occurred when GCBLat1 cells were treated with trichostatin A (TSA) or phorbol 12-myristate 13-acetate (TPA). It suggests CyHV-2 can remain latent in vitro and can reactivate under stress condition.
Collapse
|
13
|
Mo ZQ, Lai XL, Wang WT, Chen HP, He ZC, Han R, Wang JL, Luo XC, Li YW, Dan XM. Identification and characterization of c-raf from orange-spotted grouper (Epinephelus coioides). FISH & SHELLFISH IMMUNOLOGY 2020; 96:311-318. [PMID: 31830568 DOI: 10.1016/j.fsi.2019.12.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 12/03/2019] [Accepted: 12/09/2019] [Indexed: 06/10/2023]
Abstract
C-Raf proto-oncogene serine/threonine kinase is a mitogen-activated protein kinase (MAP) kinase kinase, which can initiate a mitogen-activated protein kinase (MAPK) cascade by phosphorylating the dual-specific MAP kinase kinases (MEK1/2), and in turn activate the extracellular signal-regulated kinases (ERK1/2). To study the function of c-Raf in teleost fish, a c-Raf cDNA sequence from orange-spotted grouper (Epinephelus coioides) was cloned. Ecc-Raf shared 81%-99% amino acid identity with other vertebrate c-Raf molecules, and shared the highest amino acid identity (99%) with Lates calcarifer c-Raf. Genomic structure analysis revealed that grouper c-Raf shared a conserved exon structure with other vertebrates. Tissue distribution showed that Ecc-Raf was mainly transcribed in systemic immune organs. Ecc-Raf was distributed throughout the cytoplasm of transfected GS cells and the overexpression of Ecc-Raf only slightly enhanced the activation of Activator protein 1. The phosphorylation levels of Ecc-Raf can be induced by PMA and H2O2 treatment, in contrast to DMSO or untreated HKLs. Moreover, the phosphorylation level of the Raf-MEK-ERK axis was downregulated after 24 h of SGIV infection. On the other hand, the total level and phosphorylation level of c-Raf significantly increased post C. irritans infection and showed an enhanced level post immunization. The results of this study suggested that the Raf-MEK-ERK cascade was involved in the response to viral or parasitic infections.
Collapse
Affiliation(s)
- Ze-Quan Mo
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China; College of Animal Science, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Xue-Li Lai
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Wan-Tao Wang
- Provincial Clinical Medical College, Fujian Medical University, Fuzhou, 305001, Fujian Province, China
| | - Hong-Ping Chen
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Zhi-Chang He
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Rui Han
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Jiu-Le Wang
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China
| | - Xiao-Chun Luo
- School of Bioscience and Biotechnology, South China University of Technology, Guangzhou, 510006, China
| | - Yan-Wei Li
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China.
| | - Xue-Ming Dan
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, China.
| |
Collapse
|
14
|
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.
Collapse
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.
| |
Collapse
|
15
|
Development of an ORF45-Derived Peptide To Inhibit the Sustained RSK Activation and Lytic Replication of Kaposi's Sarcoma-Associated Herpesvirus. J Virol 2019; 93:JVI.02154-18. [PMID: 30842327 DOI: 10.1128/jvi.02154-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 02/27/2019] [Indexed: 01/03/2023] Open
Abstract
The lytic replication of Kaposi's sarcoma-associated herpesvirus (KSHV) requires sustained extracellular signal-regulated kinase (ERK)-p90 ribosomal S6 kinase (RSK) activation, which is induced by an immediate early (IE) gene-encoded tegument protein called ORF45, to promote the late transcription and translation of viral lytic genes. An ORF45-null or single-point F66A mutation in ORF45 abolishes ORF45-RSK interaction and sustained ERK-RSK activation during lytic reactivation and subsequently results in a significant decrease in late lytic gene expression and virion production, indicating that ORF45-mediated RSK activation plays a critical role in KSHV lytic replication. Here, we demonstrate that a short ORF45-derived peptide in the RSK-binding region is sufficient for disrupting ORF45-RSK interaction, consequently suppressing lytic gene expression and virion production. We designed a nontoxic cell-permeable peptide derived from ORF45, TAT-10F10, which is composed of the ORF45 56 to 76 amino acid (aa) region and the HIV Tat protein transduction domain, and this peptide markedly inhibits KSHV lytic replication in iSLK.219 and BCBL1 cells. Importantly, this peptide enhances the inhibitory effect of rapamycin on KSHV-infected cells and decreases spontaneous and hypoxia-induced lytic replication in KSHV-positive lymphoma cells. These findings suggest that a small peptide that disrupts ORF45-RSK interaction might be a promising agent for controlling KSHV lytic infection and pathogenesis.IMPORTANCE ORF45-induced RSK activation plays an essential role in KSHV lytic replication, and ORF45-null or ORF45 F66A mutagenesis that abolishes sustained RSK activation and RSK inhibitors significantly decreases lytic replication, indicating that the ORF45-RSK association is a unique target for KSHV-related diseases. However, the side effects, low affinity, and poor efficacy of RSK modulators limit their clinical application. In this study, we developed a nontoxic cell-permeable ORF45-derived peptide from the RSK-binding region to disrupt ORF45-RSK associations and block ORF45-induced RSK activation without interfering with S6K1 activation. This peptide effectively suppresses spontaneous, hypoxia-induced, or chemically induced KSHV lytic replication and enhances the inhibitory effect of rapamycin on lytic replication and sensitivity to rapamycin in lytic KSHV-infected cells. Our results reveal that the ORF45-RSK signaling axis and KSHV lytic replication can be effectively targeted by a short peptide and provide a specific approach for treating KSHV lytic and persistent infection.
Collapse
|
16
|
Hussein HAM, Alfhili MA, Pakala P, Simon S, Hussain J, McCubrey JA, Akula SM. miRNAs and their roles in KSHV pathogenesis. Virus Res 2019; 266:15-24. [PMID: 30951791 DOI: 10.1016/j.virusres.2019.03.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 03/26/2019] [Accepted: 03/26/2019] [Indexed: 12/12/2022]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiological agent of Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), and multicentric Castleman Disease (MCD). Recent mechanistic advances have discerned the importance of microRNAs in the virus-host relationship. KSHV has two modes of replication: lytic and latent phase. KSHV entry into permissive cells, establishment of infection, and maintenance of latency are contingent upon successful modulation of the host miRNA transcriptome. Apart from host cell miRNAs, KSHV also encodes viral miRNAs. Among various cellular and molecular targets, miRNAs are appearing to be key players in regulating viral pathogenesis. Therefore, the use of miRNAs as novel therapeutics has gained considerable attention as of late. This innovative approach relies on either mimicking miRNA species by identical oligonucleotides, or selective silencing of miRNA with specific oligonucleotide inhibitors. Here, we provide an overview of KSHV pathogenesis at the molecular level with special emphasis on the various roles miRNAs play during virus infection.
Collapse
Affiliation(s)
- Hosni A M Hussein
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States; Faculty of Science, Al Azhar University, Assiut Branch, Assiut 71524, Egypt
| | - Mohammad A Alfhili
- Department of Medicine (Division of Hematology/Oncology), Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States; Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia
| | - Pranaya Pakala
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Sandra Simon
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Jaffer Hussain
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - James A McCubrey
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States
| | - Shaw M Akula
- Department of Microbiology & Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, United States.
| |
Collapse
|
17
|
Hicks JA, Trakooljul N, Liu HC. Alterations in cellular and viral microRNA and cellular gene expression in Marek's disease virus-transformed T-cell lines treated with sodium butyrate. Poult Sci 2019; 98:642-652. [PMID: 30184155 DOI: 10.3382/ps/pey412] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/09/2018] [Indexed: 11/20/2022] Open
Abstract
A shared feature of herpesviruses is their ability to enter a latent state following an initially lytic infection. Marek's disease virus serotype 1 (MDV-1) is an oncogenic avian herpesvirus. Small RNA profiling studies have suggested that microRNAs (miRNAs) are involved in viral latency. Sodium butyrate treatment is known to induce herpesvirus reactivation. The present study was undertaken to determine transcriptome and miRNome changes induced by sodium butyrate in 2 MDV-transformed cell lines, RP2 and CU115. In the first 24 h post-treatment, microarray analysis of transcriptional changes in cell lines RP2 and CU115 identified 137 and 114 differentially expressed genes, respectively. Small RNA deep-sequencing analysis identified 17 cellular miRNAs that were differentially expressed. The expression of MDV-encoded miRNAs was also altered upon treatment. Many of the genes and miRNAs that are differentially expressed are involved in regulation of the cell cycle, mitosis, DNA metabolism, and lymphocyte differentiation.
Collapse
Affiliation(s)
- Julie A Hicks
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
| | - Nares Trakooljul
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
| | - Hsiao-Ching Liu
- Department of Animal Science, North Carolina State University, Raleigh, NC 27695, USA
| |
Collapse
|
18
|
Mo ZQ, Han R, Wang JL, Ni LY, Su YL, Lai XL, He ZC, Chen HP, Li YW, Sun HY, Luo XC, Dan XM. Characterization and functional analysis of grouper (Epinephelus coioides) MEK1 and MEK2. FISH & SHELLFISH IMMUNOLOGY 2019; 84:1090-1097. [PMID: 30419398 DOI: 10.1016/j.fsi.2018.11.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 11/02/2018] [Accepted: 11/05/2018] [Indexed: 06/09/2023]
Abstract
MEK dual-specificity protein kinases are a group of mitogen-activated protein kinase kinases, which act as an integration point by transferring extracellular signals to the nucleus. To investigate the function of MEK in teleost fish, we cloned MEK1 and MEK2 cDNA sequences from the orange-spotted grouper (Epinephelus coioides). EcMEK1 and EcMEK2 shared 80% amino acid identity with each other. EcMEK1 had 89-99% amino acid identity with teleosts or mammals, whereas EcMEK2 shared 85-97% amino acid identity. The exon structures of the grouper MEK1/2 genes were conserved with zebrafish and human MEK1/2. Tissue distribution analysis showed that EcMEK1 and EcMEK2 had a similar expression pattern in grouper tissues and was mainly transcribe in systemic immune organs. Both EcMEK1 and EcMEK2 were distributed throughout the cytoplasm of transfected GS or HEK293T cells. Overexpression of EcMEK1 or EcMEK2 activated Activator protein 1 dependent luciferase. The phosphorylation levels of EcMEK1/2 and EcERK1/2 were significantly increased in head kidney leukocytes by stimulation with PMA treatment. The grouper MEK1/2-ERK1/2 axis was activated in Cryptocaryon irritans infection and showed an enhanced phosphorylation after immunization.
Collapse
Affiliation(s)
- Ze-Quan Mo
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Rui Han
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Jiu-Le Wang
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Lu-Yun Ni
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Yu-Ling Su
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Xue-Li Lai
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Zhi-Chang He
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Hong-Ping Chen
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Yan-Wei Li
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Hong-Yan Sun
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Xiao-Chun Luo
- School of Bioscience and Biotechnology, South China University of Technology, Guangzhou, 510006, PR China.
| | - Xue-Ming Dan
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China.
| |
Collapse
|
19
|
Granato M, Gilardini Montani MS, Angiolillo C, D'Orazi G, Faggioni A, Cirone M. Cytotoxic Drugs Activate KSHV Lytic Cycle in Latently Infected PEL Cells by Inducing a Moderate ROS Increase Controlled by HSF1, NRF2 and p62/SQSTM1. Viruses 2018; 11:v11010008. [PMID: 30586869 PMCID: PMC6356381 DOI: 10.3390/v11010008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/17/2018] [Accepted: 12/21/2018] [Indexed: 12/26/2022] Open
Abstract
Previous studies have indicated that cytotoxic treatments may induce or not activate viral lytic cycle activation in cancer cells latently infected by Kaposi’s sarcoma-associated herpesvirus (KSHV). To investigate the molecular mechanisms responsible for such an effect, we compared two cytotoxic treatments able to induce the viral lytic cycle, named 12-O-tetradecanoylphorbol 13-acetate (TPA) (T) in combination with sodium butyrate (B) and bortezomib (BZ), with two cytotoxic treatments that did not activate this process, named metformin (MET) and quercetin (Q). Our results indicated that TB and bortezomib increased levels of oxygen reactive species (ROS) while metformin and quercetin reduced them. The finding that N-acetylcysteine (NAC), a reactive oxigen species (ROS) scavenger, counteracted K-bZIP expression induced by TB or bortezomib, confirmed that an ROS increase played a role in KSHV lytic cycle activation. Moreover, we found that TB and bortezomib up-regulated p62/Sequestosome1(p62/SQSTM1) protein, while metformin and quercetin down-regulated it. p62/SQSTM1 silencing or the inhibition of NF-E2-related factor 2 (NRF2) or Heat Shock Factor 1 (HSF1), that mediate p62/SQSTM1 transcription, also reduced KSHV lytic antigen expression induced by TB or bortezomib. Interestingly, such combination treatments further increased intracellular ROS and cytotoxicity induced by the single TB or bortezomib treatment, suggesting that NRF2, HSF1 and p62/SQSTM1 keep the ROS level under control, allowing primary effusion lymphoma (PEL) cells to continue to survive and KSHV to replicate.
Collapse
Affiliation(s)
- Marisa Granato
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Viale Regina Elena 324, 00161 Rome, Italy.
| | - Maria Saveria Gilardini Montani
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Viale Regina Elena 324, 00161 Rome, Italy.
| | - Camilla Angiolillo
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Viale Regina Elena 324, 00161 Rome, Italy.
| | - Gabriella D'Orazi
- Department of Research, Advanced Diagnostics, and Technological Innovation, Regina Elena National Cancer Institute, 00144 Rome, Italy.
- Department of Medical, Oral and Biotechnological Sciences, University "G. d'Annunzio", 66013 Chieti, Italy.
| | - Alberto Faggioni
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Viale Regina Elena 324, 00161 Rome, Italy.
| | - Mara Cirone
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy, Laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Viale Regina Elena 324, 00161 Rome, Italy.
| |
Collapse
|
20
|
Manners O, Murphy JC, Coleman A, Hughes DJ, Whitehouse A. Contribution of the KSHV and EBV lytic cycles to tumourigenesis. Curr Opin Virol 2018; 32:60-70. [PMID: 30268927 PMCID: PMC6259586 DOI: 10.1016/j.coviro.2018.08.014] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/24/2018] [Indexed: 12/21/2022]
Abstract
Kaposi's Sarcoma-associated herpesvirus (KSHV) and Epstein Barr virus (EBV) are the causative agents of several malignancies. Like all herpesviruses, KSHV and EBV undergo distinct latent and lytic replication programmes. The transition between these states allows the establishment of a lifelong persistent infection, dissemination to sites of disease and the spread to new hosts. Latency-associated viral proteins have been well characterised in transformation and tumourigenesis pathways; however, a number of studies have shown that abrogation of KSHV and EBV lytic gene expression impairs the oncogenesis of several cancers. Furthermore, several lytically expressed proteins have been functionally tethered to the angioproliferative and anti-apoptotic phenotypes of virus-infected cells. As a result, the investigation and therapeutic targeting of KSHV and EBV lytic cycles may be essential for the treatment of their associated malignancies.
Collapse
Affiliation(s)
- Oliver Manners
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - James C Murphy
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Alex Coleman
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - David J Hughes
- School of Biology, Biomolecular Sciences Building, University of St Andrews, Fife, KY16 9AJ, United Kingdom
| | - Adrian Whitehouse
- School of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom; Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom; Department of Biochemistry & Microbiology, Rhodes University, Grahamstown, 6140, South Africa.
| |
Collapse
|
21
|
Hopcraft SE, Pattenden SG, James LI, Frye S, Dittmer DP, Damania B. Chromatin remodeling controls Kaposi's sarcoma-associated herpesvirus reactivation from latency. PLoS Pathog 2018; 14:e1007267. [PMID: 30212584 PMCID: PMC6136816 DOI: 10.1371/journal.ppat.1007267] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 08/07/2018] [Indexed: 01/08/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the etiologic agent of three human malignancies, the endothelial cell cancer Kaposi's sarcoma, and two B cell cancers, Primary Effusion Lymphoma and multicentric Castleman's disease. KSHV has latent and lytic phases of the viral life cycle, and while both contribute to viral pathogenesis, lytic proteins contribute to KSHV-mediated oncogenesis. Reactivation from latency is driven by the KSHV lytic gene transactivator RTA, and RTA transcription is controlled by epigenetic modifications. To identify host chromatin-modifying proteins that are involved in the latent to lytic transition, we screened a panel of inhibitors that target epigenetic regulatory proteins for their ability to stimulate KSHV reactivation. We found several novel regulators of viral reactivation: an inhibitor of Bmi1, PTC-209, two additional histone deacetylase inhibitors, Romidepsin and Panobinostat, and the bromodomain inhibitor (+)-JQ1. All of these compounds stimulate lytic gene expression, viral genome replication, and release of infectious virions. Treatment with Romidepsin, Panobinostat, and PTC-209 induces histone modifications at the RTA promoter, and results in nucleosome depletion at this locus. Finally, silencing Bmi1 induces KSHV reactivation, indicating that Bmi1, a member of the Polycomb repressive complex 1, is critical for maintaining KSHV latency.
Collapse
Affiliation(s)
- Sharon E. Hopcraft
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Samantha G. Pattenden
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Lindsey I. James
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Stephen Frye
- Center for Integrative Chemical Biology and Drug Discovery, Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Dirk P. Dittmer
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center, Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America
| |
Collapse
|
22
|
Visochek L, Cohen-Armon M. PARP1-Erk synergism in proliferating cells. Oncotarget 2018; 9:29140-29145. [PMID: 30018741 PMCID: PMC6044375 DOI: 10.18632/oncotarget.25633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 05/31/2018] [Indexed: 01/04/2023] Open
Abstract
A synergism between PARP1 and phosphorylated Erk mediating IEG (immediate early gene) expression has been recently reported in cerebral neurons and cardiomyocytes. Stimulation induced PARP-Erk synergism was required for IEG expression underlying synaptic plasticity and long-term memory acquisition during learning. It was similarly required for cardiomyocytes development. Here, we identified this mechanism in Erk-induced gene expression promoting proliferation. This mechanism can be targeted in malignant cells.
Collapse
Affiliation(s)
- Leonid Visochek
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
| | - Malka Cohen-Armon
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv 69978, Israel
- Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv 69978, Israel
| |
Collapse
|
23
|
Hussein HAM, Okafor IB, Walker LR, Abdel-Raouf UM, Akula SM. Cellular and viral oncogenes: the key to unlocking unknowns of Kaposi's sarcoma-associated herpesvirus pathogenesis. Arch Virol 2018; 163:2633-2643. [PMID: 29936609 DOI: 10.1007/s00705-018-3918-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 06/08/2018] [Indexed: 02/06/2023]
Abstract
Oncogenic viruses carry an extensive arsenal of oncogenes for hijacking cellular pathways. Notably, variations in oncogenes among tumor-producing viruses give rise to different mechanisms for cellular transformation. Specifically, Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus able to infect and transform a variety of cell types. The oncogenicity of KSHV disseminates from the virus' ability to induce and encode a wide variety of both cellular and viral oncogenes. Such an array of cellular and viral oncogenes enables KSHV to induce the malignant phenotype of a KSHV-associated cancer. Evolutionarily, KSHV has acquired many oncogenic homologues capable of inducing cell proliferation, cell differentiation, cell survival, and immune evasion. Integration between inducing and encoding oncogenes plays a vital role in KSHV pathogenicity. KSHV is alleged to harbor the highest number of potential oncogenes by which a virus promotes cellular transformation and malignancy. Many KSHV inducing/encoding oncogenes are mainly expressed during the latent phase of KSHV infection, a period required for virus establishment of malignant cellular transformation. Elucidation of the exact mechanism(s) by which oncogenes promote KSHV pathogenicity would not only give rise to potential novel therapeutic targets/drugs but would also add to our understanding of cancer biology. The scope of this review is to examine the roles of the most important cellular and viral oncogenes involved in KSHV pathogenicity.
Collapse
Affiliation(s)
- Hosni A M Hussein
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA
| | - Ikenna B Okafor
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA
| | - Lia R Walker
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA
| | - Usama M Abdel-Raouf
- Faculty of Science, Al Azhar University, Assiut Branch, Assiut, 71524, Egypt
| | - Shaw M Akula
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, NC, 27834, USA.
| |
Collapse
|
24
|
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.
Collapse
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.
| |
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
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.
Collapse
|
27
|
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.
Collapse
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:
| |
Collapse
|
28
|
KSHV and the Role of Notch Receptor Dysregulation in Disease Progression. Pathogens 2017; 6:pathogens6030034. [PMID: 28777778 PMCID: PMC5617991 DOI: 10.3390/pathogens6030034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 12/17/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of two human cancers, Kaposi's Sarcoma (KS) and primary effusion lymphoma (PEL), and a lymphoproliferation, Multicentric Castleman's Disease (MCD). Progression to tumor development in KS is dependent upon the reactivation of the virus from its latent state. We, and others, have shown that the Replication and transcriptional activator (Rta) protein is the only viral gene product that is necessary and sufficient for viral reactivation. To induce the reactivation and transcription of viral genes, Rta forms a complex with the cellular DNA binding component of the canonical Notch signaling pathway, recombination signal binding protein for Jk (RBP-Jk). Formation of this Rta:RBP-Jk complex is necessary for viral reactivation to occur. Expression of activated Notch has been shown to be dysregulated in KSHV infected cells and to be necessary for cell growth and disease progression. Studies into the involvement of activated Notch in viral reactivation have yielded varied results. In this paper, we review the current literature regarding Notch dysregulation by KSHV and its role in viral infection and cellular pathogenesis.
Collapse
|
29
|
Aneja KK, Yuan Y. Reactivation and Lytic Replication of Kaposi's Sarcoma-Associated Herpesvirus: An Update. Front Microbiol 2017; 8:613. [PMID: 28473805 PMCID: PMC5397509 DOI: 10.3389/fmicb.2017.00613] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/27/2017] [Indexed: 12/30/2022] Open
Abstract
The life cycle of Kaposi’s sarcoma-associated herpesvirus (KSHV) consists of two phases, latent and lytic. The virus establishes latency as a strategy for avoiding host immune surveillance and fusing symbiotically with the host for lifetime persistent infection. However, latency can be disrupted and KSHV is reactivated for entry into the lytic replication. Viral lytic replication is crucial for efficient dissemination from its long-term reservoir to the sites of disease and for the spread of the virus to new hosts. The balance of these two phases in the KSHV life cycle is important for both the virus and the host and control of the switch between these two phases is extremely complex. Various environmental factors such as oxidative stress, hypoxia, and certain chemicals have been shown to switch KSHV from latency to lytic reactivation. Immunosuppression, unbalanced inflammatory cytokines, and other viral co-infections also lead to the reactivation of KSHV. This review article summarizes the current understanding of the initiation and regulation of KSHV reactivation and the mechanisms underlying the process of viral lytic replication. In particular, the central role of an immediate-early gene product RTA in KSHV reactivation has been extensively investigated. These studies revealed multiple layers of regulation in activation of RTA as well as the multifunctional roles of RTA in the lytic replication cascade. Epigenetic regulation is known as a critical layer of control for the switch of KSHV between latency and lytic replication. The viral non-coding RNA, PAN, was demonstrated to play a central role in the epigenetic regulation by serving as a guide RNA that brought chromatin remodeling enzymes to the promoters of RTA and other lytic genes. In addition, a novel dimension of regulation by microPeptides emerged and has been shown to regulate RTA expression at the protein level. Overall, extensive investigation of KSHV reactivation and lytic replication has revealed a sophisticated regulation network that controls the important events in KSHV life cycle.
Collapse
Affiliation(s)
- Kawalpreet K Aneja
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, PhiladelphiaPA, USA
| | - Yan Yuan
- Department of Microbiology, University of Pennsylvania School of Dental Medicine, PhiladelphiaPA, USA
| |
Collapse
|
30
|
Chloroquine inhibits lytic replication of Kaposi's sarcoma-associated herpesvirus by disrupting mTOR and p38-MAPK activation. Antiviral Res 2016; 133:223-33. [PMID: 27521848 DOI: 10.1016/j.antiviral.2016.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/19/2022]
Abstract
Lytic infection is essential for the persistent infection and pathogenesis of Kaposi's sarcoma-associated herpesvirus (KSHV), and inhibiting KSHV lytic replication may effectively prevent the occurrence of KSHV-related diseases. Chloroquine (CQ), a well-known antimalarial drug and autophagy inhibitor, exerts broad-spectrum antiviral effects and shows anti-cancer therapeutic potential. However, the ability of CQ and its derivatives to control infection of oncogenic γ-herpesvirus remains undefined. Here we reveal that CQ suppresses KSHV lytic gene expression and virion production, and shows cytotoxicity toward KSHV lytically infected B cells at clinically acceptable doses. CQ suppresses mTOR and p38-MAPK pathway activation during KSHV lytic replication but not latent infection. Furthermore, CQ blocks Epstein-Barr virus (EBV) lytic replication via a distinct mechanism that is invoked to block virion production but does not affect viral gene expression. These results suggest that CQ is an effective antiviral drug against KSHV lytic infection. Our findings indicate that CQ treatment should be considered for controlling KSHV-related diseases, particularly for primary use in co-infection of KSHV with malaria.
Collapse
|
31
|
Kim Y, Cha S, Seo T. Activation of the phosphatidylinositol 3-kinase/Akt pathway by viral interferon regulatory factor 2 of Kaposi's sarcoma-associated herpesvirus. Biochem Biophys Res Commun 2016; 470:650-656. [DOI: 10.1016/j.bbrc.2016.01.087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 01/14/2016] [Indexed: 12/22/2022]
|
32
|
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.
Collapse
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:
| |
Collapse
|
33
|
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.
Collapse
|
34
|
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.
Collapse
|
35
|
Gonnella R, Granato M, Farina A, Santarelli R, Faggioni A, Cirone M. PKC theta and p38 MAPK activate the EBV lytic cycle through autophagy induction. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1586-95. [PMID: 25827954 DOI: 10.1016/j.bbamcr.2015.03.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/17/2015] [Accepted: 03/20/2015] [Indexed: 01/14/2023]
Abstract
PKC activation by combining TPA with sodium butyrate (T/B) represents the most effective and widely used strategy to induce the Epstein-Barr virus (EBV) lytic cycle. The results obtained in this study show that novel PKCθ is involved in such process and that it acts through the activation of p38 MAPK and autophagy induction. Autophagy, a mechanism of cellular defense in stressful conditions, is manipulated by EBV to enhance viral replication. Besides promoting the EBV lytic cycle, the activation of p38 and autophagy resulted in a pro-survival effect, as indicated by p38 or ATG5 knocking down experiments. However, this pro-survival role was counteracted by a pro-death activity of PKCθ, due to the dephosphorylation of AKT. In conclusion, this study reports, for the first time, that T/B activates a PKCθ-p38 MAPK axis in EBV infected B cells, that promotes the viral lytic cycle and cell survival and dephosphorylates AKT, balancing cell life and cell death.
Collapse
Affiliation(s)
- Roberta Gonnella
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy
| | - Marisa Granato
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy
| | - Antonella Farina
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy
| | - Roberta Santarelli
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy
| | - Alberto Faggioni
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy.
| | - Mara Cirone
- Department of Experimental Medicine, "Sapienza" University of Rome, Italy.
| |
Collapse
|
36
|
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.
Collapse
|
37
|
Downregulation of IRF4 induces lytic reactivation of KSHV in primary effusion lymphoma cells. Virology 2014; 458-459:4-10. [PMID: 24928034 DOI: 10.1016/j.virol.2014.04.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 01/07/2014] [Accepted: 04/13/2014] [Indexed: 01/24/2023]
Abstract
Primary effusion lymphoma (PEL), associated with the latent infection by KSHV, constitutively expresses interferon-regulatory factor 4 (IRF4). We recently showed that IRF4 differentially regulates expression of cellular interferon-stimulated genes (ISGs) and viral genes (Forero et al., 2013). Here, using inducible IRF4 knockdown, we demonstrate that IRF4 silencing results in enhanced transcription of KSHV replication transactivator RTA. As a result viral transcription is increased leading to virus reactivation. Taken together, our results show that IRF4 helps maintain the balance between latency and KSHV reactivation in PEL cells.
Collapse
|
38
|
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.
Collapse
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
| |
Collapse
|
39
|
Systematic analysis of a xenograft mice model for KSHV+ primary effusion lymphoma (PEL). PLoS One 2014; 9:e90349. [PMID: 24587336 PMCID: PMC3938717 DOI: 10.1371/journal.pone.0090349] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 01/28/2014] [Indexed: 11/19/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus is the causative agent of primary effusion lymphoma (PEL), which arises preferentially in the setting of infection with human immunodeficiency virus (HIV). Even with standard cytotoxic chemotherapy, PEL continues to cause high mortality rates, requiring the development of novel therapeutic strategies. PEL xenograft models employing immunodeficient mice have been used to study the in vivo effects of a variety of therapeutic approaches. However, it remains unclear whether these xenograft models entirely reflect clinical presentations of KSHV(+) PEL, especially given the recent description of extracavitary solid tumor variants arising in patients. In addition, effusion and solid tumor cells propagated in vivo exhibit unique biology, differing from one another or from their parental cell lines propagated through in vitro culture. Therefore, we used a KSHV(+) PEL/BCBL-1 xenograft model involving non-obese diabetic/severe-combined immunodeficient (NOD/SCID) mice, and compared characteristics of effusion and solid tumors with their parent cell culture-derived counterparts. Our results indicate that although this xenograft model can be used for study of effusion and solid lymphoma observed in patients, tumor cells in vivo display unique features to those passed in vitro, including viral lytic gene expression profile, rate of solid tumor development, the host proteins and the complex of tumor microenvironment. These items should be carefully considered when the xenograft model is used for testing novel therapeutic strategies against KSHV-related lymphoma.
Collapse
|
40
|
Arias C, Weisburd B, Stern-Ginossar N, Mercier A, Madrid AS, Bellare P, Holdorf M, Weissman JS, Ganem D. KSHV 2.0: a comprehensive annotation of the Kaposi's sarcoma-associated herpesvirus genome using next-generation sequencing reveals novel genomic and functional features. PLoS Pathog 2014; 10:e1003847. [PMID: 24453964 PMCID: PMC3894221 DOI: 10.1371/journal.ppat.1003847] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 10/20/2013] [Indexed: 01/08/2023] Open
Abstract
Productive herpesvirus infection requires a profound, time-controlled remodeling of the viral transcriptome and proteome. To gain insights into the genomic architecture and gene expression control in Kaposi's sarcoma-associated herpesvirus (KSHV), we performed a systematic genome-wide survey of viral transcriptional and translational activity throughout the lytic cycle. Using mRNA-sequencing and ribosome profiling, we found that transcripts encoding lytic genes are promptly bound by ribosomes upon lytic reactivation, suggesting their regulation is mainly transcriptional. Our approach also uncovered new genomic features such as ribosome occupancy of viral non-coding RNAs, numerous upstream and small open reading frames (ORFs), and unusual strategies to expand the virus coding repertoire that include alternative splicing, dynamic viral mRNA editing, and the use of alternative translation initiation codons. Furthermore, we provide a refined and expanded annotation of transcription start sites, polyadenylation sites, splice junctions, and initiation/termination codons of known and new viral features in the KSHV genomic space which we have termed KSHV 2.0. Our results represent a comprehensive genome-scale image of gene regulation during lytic KSHV infection that substantially expands our understanding of the genomic architecture and coding capacity of the virus. Kaposi's sarcoma-associated herpesvirus (KSHV) is a cancer-causing agent in immunocompromised patients that establishes long-lasting infections in its hosts. Initially described in 1994 and extensively studied ever since, KSHV molecular biology is understood in broad outline, but many detailed questions are still to be resolved. After almost two decades, specific aspects pertaining to the organization of the KSHV genome as well as the fate of the viral transcripts during the productive stages of infection remain unexplored. Here we use a systematic genome-wide approach to investigate changes in gene and protein expression during the productive stage of infection known as the lytic cycle. We found that the viral genome has a large coding capacity, capable of generating at least 45% more products than initially anticipated by bioinformatic analyses alone, and that it uses multiple strategies to expand its coding capacity well beyond what is determined solely by the DNA sequence of its genome. We also provide an expanded and highly detailed annotation of known and new genomic features in KSHV. We have termed this new architectural and functional annotation KSHV 2.0. Our results indicate that viral genomes are more complex than anticipated, and that they are subject to tight mechanisms of regulation to ensure correct gene expression.
Collapse
Affiliation(s)
- Carolina Arias
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
- * E-mail:
| | - Ben Weisburd
- Novartis Vaccines and Diagnostics, Bioinformatics, Emeryville, California, United States of America
| | - Noam Stern-Ginossar
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Alexandre Mercier
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
| | - Alexis S. Madrid
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
| | - Priya Bellare
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
| | - Meghan Holdorf
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
| | - Jonathan S. Weissman
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, United States of America
| | - Don Ganem
- Novartis Institute for Biomedical Research, Department of Infectious Diseases, Emeryville, California, United States of America
| |
Collapse
|
41
|
Wakao K, Watanabe T, Takadama T, Ui S, Shigemi Z, Kagawa H, Higashi C, Ohga R, Taira T, Fujimuro M. Sangivamycin induces apoptosis by suppressing Erk signaling in primary effusion lymphoma cells. Biochem Biophys Res Commun 2014; 444:135-40. [PMID: 24434142 DOI: 10.1016/j.bbrc.2014.01.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 01/08/2014] [Indexed: 01/24/2023]
Abstract
Sangivamycin, a structural analog of adenosine and antibiotic exhibiting antitumor and antivirus activities, inhibits protein kinase C and the synthesis of both DNA and RNA. Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi's sarcoma-associated herpesvirus (KSHV) in immunosuppressed patients and HIV-infected homosexual males. PEL cells are derived from post-germinal center B cells, and are infected with KSHV. Herein, we asked if sangivamycin might be useful to treat PEL. We found that sangivamycin killed PEL cells, and we explored the underlying mechanism. Sangivamycin treatment drastically decreased the viability of PEL cell lines compared to KSHV-uninfected B lymphoma cell lines. Sangivamycin induced the apoptosis of PEL cells by activating caspase-7 and -9. Further, sangivamycin suppressed the phosphorylation of Erk1/2 and Akt, thus inhibiting activation of the proteins. Inhibitors of Akt and MEK suppressed the proliferation of PEL cells compared to KSHV-uninfected cells. It is known that activation of Erk and Akt signaling inhibits apoptosis and promotes proliferation in PEL cells. Our data therefore suggest that sangivamycin induces apoptosis by inhibiting Erk and Akt signaling in such cells. We next investigated whether sangivamycin, in combination with an HSP90 inhibitor geldanamycin (GA) or valproate (valproic acid), potentiated the cytotoxic effects of the latter drugs on PEL cells. Compared to treatment with GA or valproate alone, the addition of sangivamycin enhanced cytotoxic activity. Our data thus indicate that sangivamycin may find clinical utility as a novel anti-cancer agent targeting PEL.
Collapse
Affiliation(s)
- Kazufumi Wakao
- Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511, Japan
| | - Tadashi Watanabe
- Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412, Japan
| | - Tadatoshi Takadama
- Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511, Japan
| | - Sadaharu Ui
- Department of Biotechnology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Kofu-shi 400-8511, Japan
| | - Zenpei Shigemi
- Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412, Japan
| | - Hiroki Kagawa
- Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412, Japan
| | - Chizuka Higashi
- Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898, Japan
| | - Rie Ohga
- Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898, Japan
| | - Takahiro Taira
- Department of Molecular Cell Biology, Faculty of Medicine, University of Yamanashi, Chuoh-shi 409-3898, Japan
| | - Masahiro Fujimuro
- Department of Cell Biology, Kyoto Pharmaceutical University, Misasagi-Shichonocho 1, Yamashinaku, Kyoto 607-8412, Japan.
| |
Collapse
|
42
|
Analysis of Kaposi's sarcoma-associated herpesvirus latent replication using a real-time polymerase chain reaction technique. J Virol Methods 2013; 193:660-6. [DOI: 10.1016/j.jviromet.2013.07.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 07/29/2013] [Accepted: 07/31/2013] [Indexed: 11/19/2022]
|
43
|
Role of human herpesvirus 8 interleukin-6-activated gp130 signal transducer in primary effusion lymphoma cell growth and viability. J Virol 2013; 87:10816-27. [PMID: 23903842 DOI: 10.1128/jvi.02047-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human herpesvirus 8 (HHV-8) infection is associated with Kaposi's sarcoma, primary effusion lymphoma (PEL), and multicentric Castleman's disease. HHV-8-encoded viral interleukin-6 (vIL-6) is believed to contribute to pathogenesis via proproliferative, antiapoptotic, and proangiogenic activities. In PEL cells, vIL-6 is produced in functional amounts during viral latency and promotes the growth of these cells, mediating its activity from the endoplasmic reticulum (ER), where it is predominantly localized. This vIL-6 activity is dependent, in part, on its interaction with a splice variant of vitamin K epoxide reductase complex subunit 1 (VKORC1), termed VKORC1 variant 2 (VKORC1v2). Here we report that the IL-6 signal transducer, gp130, which can support vIL-6 signaling from the ER, is also required for optimal PEL cell growth and viability. Levels of activated extracellular regulated kinases (ERKs) 1 and 2 and signal transducer and activator of transcription 1 (STAT1) and STAT3, phosphorylated following gp130 stimulation, were reduced in gp130-depleted BCBL-1 and BC-1 cells. Diminished STAT activation was also detected in JSC-1 and BC-3 cells. Effects of gp130 depletion on growth could be mimicked by short hairpin RNA targeting of ERKs 1 and 2 or by depletion of STAT3. Finally, inhibition of vIL-6-gp130 association specifically within the ER compartment suppressed cell proliferation and viability, mirroring the effects of gp130 depletion. Combined, these data demonstrate that gp130, in addition to VKORC1v2, is essential for normal PEL cell growth and survival and that ER-localized vIL-6-gp130 interactions are critical for these activities. Targeting of intracellular vIL-6-gp130 interactions could potentially provide a means of PEL therapy.
Collapse
|
44
|
Conant KL, Kaleeba JAR. Dangerous liaisons: molecular basis for a syndemic relationship between Kaposi's sarcoma and P. falciparum malaria. Front Microbiol 2013; 4:35. [PMID: 23487416 PMCID: PMC3594938 DOI: 10.3389/fmicb.2013.00035] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Accepted: 02/07/2013] [Indexed: 11/13/2022] Open
Abstract
The most severe manifestations of malaria (caused by Plasmodium falciparum) occur as a direct result of parasitemia following invasion of erythrocytes by post-liver blood-stage merozoites, and during subsequent cyto-adherence of infected erythrocytes to the vascular endothelium. However, the disproportionate epidemiologic clustering of severe malaria with aggressive forms of endemic diseases such as Kaposi's sarcoma (KS), a neoplasm that is etiologically linked to infection with KS-associated herpesvirus (KSHV), underscores the significance of previously unexplored co-pathogenetic interactions that have the potential to modify the overall disease burden in co-infected individuals. Based on recent studies of the mechanisms that P. falciparum and KSHV have evolved to interact with their mutual human host, several new perspectives are emerging that highlight a surprising convergence of biological themes potentially underlying their associated co-morbidities. Against this background, ongoing studies are rapidly constructing a fascinating new paradigm in which the major host receptors that control parasite invasion (Basigin/CD147) and cyto-adherence (CD36) are, surprisingly, also important targets for exploitation by KSHV. In this article, we consider the major pathobiological implications of the co-option of Basigin/CD147 and CD36 signaling pathways by both P. falciparum and KSHV, not only as essential host factors for parasite persistence but also as important mediators of the pro-angiogenic phenotype within the virus-infected endothelial microenvironment. Consequently, the triangulation of interactions between P. falciparum, KSHV, and their mutual human host articulates a syndemic relationship that points to a conceptual framework for prevalence of aggressive forms of KS in malaria-endemic areas, with implications for the possibility of dual-use therapies against these debilitating infections in resource-limited parts of the world.
Collapse
Affiliation(s)
| | - Johnan A. R. Kaleeba
- Department of Microbiology and Immunology, Uniformed Services University of the Health SciencesBethesda, MD, USA
| |
Collapse
|
45
|
Distinct roles for extracellular signal-regulated kinase 1 (ERK1) and ERK2 in the structure and production of a primate gammaherpesvirus. J Virol 2012; 86:9721-36. [PMID: 22740395 DOI: 10.1128/jvi.00695-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
During their progression from intranuclear capsids to mature trilaminar virions, herpesviruses incorporate an extensive array of viral as well as a smaller subset of cellular proteins. Our laboratory previously reported that rhesus monkey rhadinovirus (RRV), a close homolog of the human pathogen Kaposi's sarcoma-associated herpesvirus (KSHV), is comprised of at least 33 different virally encoded proteins. In the current study, we found that RRV infection activated the extracellular signal-regulated kinase (ERK) pathway and nascent virions preferentially incorporated the activated form of ERK2 (pERK2) into the tegument. This was evident even in the face of greatly diminished stores of intracellular ERK2, suggesting a clear bias toward the incorporation of pERK2 into the RRV particle. Similar to earlier findings with KSHV, activation of ERK was essential for the production of lytic viral proteins and virions. Knockdown of intracellular ERK, however, failed to inhibit virus production, likely due to maintenance of residual pools of intracellular pERK2. Paradoxically, selective knockdown of ERK1 enhanced virion production nearly 5-fold and viral titers more than 10-fold. These data are the first to implicate ERK1 as a negative regulator of lytic replication in a herpesvirus and the first to demonstrate the incorporation of an activated signaling molecule within a herpesvirus. Together, the results further our understanding of how herpesviruses interact with host cells during infection and demonstrate how this family of viruses can exploit cellular signal transduction pathways to modulate their own replication.
Collapse
|
46
|
Dyson OF, Walker LR, Whitehouse A, Cook PP, Akula SM. Resveratrol inhibits KSHV reactivation by lowering the levels of cellular EGR-1. PLoS One 2012; 7:e33364. [PMID: 22428032 PMCID: PMC3299779 DOI: 10.1371/journal.pone.0033364] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 02/12/2012] [Indexed: 12/22/2022] Open
Abstract
In the field of herpesvirus research, the exact molecular mechanism by which such viruses reactivate from latency remains elusive. Kaposi's sarcoma-associated herpesvirus (KSHV) primarily exists in a latent state, while only 1–3% of cells support lytic infection at any specific time. KSHV reactivation from latency is an exceedingly intricate process mediated by the integration of viral and cellular factors. Previously, our lab has described early growth response-1 (Egr-1) as an essential component for the KSHV reactivation process via its ability to mediate transcription of KSHV ORF50, the gene encoding for replication and transcription activator (RTA), a viral component known to control the switch from latent to lytic infection. In here, electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) experiments revealed that Egr-1 binds KSHV ORF50 promoter (ORF50P) in at least two different GC-rich binding domains. Expression profiles of cellular egr-1 and KSHV-encoded ORF50 follow a similar pattern during de novo KSHV infection. Over-expressing Egr-1, a signaling component downstream of Raf>MEK>ERK1/2, in KSHV-infected cells activates KSHV lytic replication. Through performing more physiologically relevant experiments, we analyzed the effect of a dietary supplement containing resveratrol on KSHV-infected cells. Our results, for the first time, demonstrate resveratrol to act in lowering ERK1/2 activity and expression of Egr-1 in KSHV-infected cells, resulting in the suppression of virus reactivation from latency. Taken together, these findings will undoubtedly contribute to future studies on not only combating KSHV related disease conditions, but also on other herpesviruses-induced pathogenesis.
Collapse
Affiliation(s)
- Ossie F. Dyson
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Lia R. Walker
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Adrian Whitehouse
- Faculty of Biological Sciences, Institute of Molecular and Cellular Biology, University of Leeds, Leeds, United Kingdom
| | - Paul P. Cook
- Department of Internal Medicine, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Shaw M. Akula
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
47
|
Tiled microarray identification of novel viral transcript structures and distinct transcriptional profiles during two modes of productive murine gammaherpesvirus 68 infection. J Virol 2012; 86:4340-57. [PMID: 22318145 DOI: 10.1128/jvi.05892-11] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
We applied a custom tiled microarray to examine murine gammaherpesvirus 68 (MHV68) polyadenylated transcript expression in a time course of de novo infection of fibroblast cells and following phorbol ester-mediated reactivation from a latently infected B cell line. During de novo infection, all open reading frames (ORFs) were transcribed and clustered into four major temporal groups that were overlapping yet distinct from clusters based on the phorbol ester-stimulated B cell reactivation time course. High-density transcript analysis at 2-h intervals during de novo infection mapped gene boundaries with a 20-nucleotide resolution, including a previously undefined ORF73 transcript and the MHV68 ORF63 homolog of Kaposi's sarcoma-associated herpesvirus vNLRP1. ORF6 transcript initiation was mapped by tiled array and confirmed by 5' rapid amplification of cDNA ends. The ∼1.3-kb region upstream of ORF6 was responsive to lytic infection and MHV68 RTA, identifying a novel RTA-responsive promoter. Transcription in intergenic regions consistent with the previously defined expressed genomic regions was detected during both types of productive infection. We conclude that the MHV68 transcriptome is dynamic and distinct during de novo fibroblast infection and upon phorbol ester-stimulated B cell reactivation, highlighting the need to evaluate further transcript structure and the context-dependent molecular events that govern viral gene expression during chronic infection.
Collapse
|
48
|
Saji C, Higashi C, Niinaka Y, Yamada K, Noguchi K, Fujimuro M. Proteasome inhibitors induce apoptosis and reduce viral replication in primary effusion lymphoma cells. Biochem Biophys Res Commun 2011; 415:573-8. [PMID: 22074820 DOI: 10.1016/j.bbrc.2011.10.107] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Accepted: 10/25/2011] [Indexed: 11/29/2022]
Abstract
Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by Kaposi's sarcoma-associated herpesvirus (KSHV). This study provides evidence that proteasomal activity is required for both survival of PEL cells stably harboring the KSHV genome and viral replication of KSHV. We evaluated the cytotoxic effects of proteasome inhibitors on PEL cells. The proteasome inhibitors MG132, lactacystin, and proteasome inhibitor I dramatically inhibited cell proliferation and induced apoptosis of PEL cells through the accumulation of p21 and p27. Furthermore, proteasome inhibitors induced the stabilization of NF-κB inhibitory molecule (IκBα) and suppressed the transcriptional activity of NF-κB in PEL cells. The NF-κB specific inhibitor BAY11-7082 also induced apoptosis in PEL cells. The constitutive activation of NF-κB signaling is essential for the survival and growth of B cell lymphoma cells, including PEL cells. NF-κB signaling is upregulated by proteasome-dependent degradation of IκBα. The suppression of NF-κB signaling by proteasome inhibitors may contribute to the induction of apoptosis in PEL cells. In addition, proteasome activity is required for KSHV replication in KSHV latently infected PEL cells. MG132 reduced the production of progeny virus from PEL cells at low concentrations, which do not affect PEL cell growth. These findings suggest that proteasome inhibitors may represent a novel strategy for the treatment of KSHV infection and KSHV-associated lymphomas.
Collapse
Affiliation(s)
- Chiaki Saji
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan
| | | | | | | | | | | |
Collapse
|
49
|
Qin D, Feng N, Fan W, Ma X, Yan Q, Lv Z, Zeng Y, Zhu J, Lu C. Activation of PI3K/AKT and ERK MAPK signal pathways is required for the induction of lytic cycle replication of Kaposi's sarcoma-associated herpesvirus by herpes simplex virus type 1. BMC Microbiol 2011; 11:240. [PMID: 22032493 PMCID: PMC3215226 DOI: 10.1186/1471-2180-11-240] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 10/27/2011] [Indexed: 12/14/2022] Open
Abstract
Background Kaposi's sarcoma-associated herpesvirus (KSHV) is causally linked to several acquired immunodeficiency syndrome-related malignancies, including Kaposi's sarcoma (KS), primary effusion lymphoma (PEL) and a subset of multicentric Castleman's disease. Regulation of viral lytic replication is critical to the initiation and progression of KS. Recently, we reported that herpes simplex virus type 1 (HSV-1) was an important cofactor that activated lytic cycle replication of KSHV. Here, we further investigated the possible signal pathways involved in HSV-1-induced reactivation of KSHV. Results By transfecting a series of dominant negative mutants and protein expressing constructs and using pharmacologic inhibitors, we found that either Janus kinase 1 (JAK1)/signal transducer and activator of transcription 3 (STAT3) or JAK1/STAT6 signaling failed to regulate HSV-1-induced KSHV replication. However, HSV-1 infection of BCBL-1 cells activated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB, also called AKT) pathway and inactivated phosphatase and tensin homologue deleted on chromosome ten (PTEN) and glycogen synthase kinase-3β (GSK-3β). PTEN/PI3K/AKT/GSK-3β pathway was found to be involved in HSV-1-induced KSHV reactivation. Additionally, extracellular signal-regulated protein kinase (ERK) mitogen-activated protein kinase (MAPK) pathway also partially contributed to HSV-1-induced KSHV replication. Conclusions HSV-1 infection stimulated PI3K/AKT and ERK MAPK signaling pathways that in turn contributed to KSHV reactivation, which provided further insights into the molecular mechanism controlling KSHV lytic replication, particularly in the context of HSV-1 and KSHV co-infection.
Collapse
Affiliation(s)
- Di Qin
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, 140 Hanzhong Road, Nanjing 210029, PR China
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Kuang E, Fu B, Liang Q, Myoung J, Zhu F. Phosphorylation of eukaryotic translation initiation factor 4B (EIF4B) by open reading frame 45/p90 ribosomal S6 kinase (ORF45/RSK) signaling axis facilitates protein translation during Kaposi sarcoma-associated herpesvirus (KSHV) lytic replication. J Biol Chem 2011; 286:41171-41182. [PMID: 21994950 DOI: 10.1074/jbc.m111.280982] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Open reading frame 45 (ORF45) of Kaposi sarcoma-associated herpesvirus (KSHV) causes sustained activation of p90 ribosomal S6 kinase (RSK), which is crucial for KSHV lytic replication, but the exact functional roles remain to be determined. To characterize the biological consequence of persistent RSK activation by ORF45, we screened known cellular substrates of RSK. We found that ORF45 induced phosphorylation of eukaryotic translation initiation factor 4B (eIF4B), increased its assembly into translation initiation complex, and subsequently facilitated protein translation. The ORF45/RSK-mediated eIF4B phosphorylation was distinguishable from that caused by the canonical AKT/mammalian target of rapamycin/ribosomal S6 kinase and MEK/ERK/RSK pathways because it was resistant to both rapamycin (an mammalian target of rapamycin inhibitor) and U1026 (an MEK inhibitor). The rapamycin and U1026 doubly insensitive eIF4B phosphorylation was induced during KSHV reactivation but was abolished if either ORF45 or RSK1/2 were ablated by siRNA, a pattern that is correlated with reduced lytic gene expression as we observed previously. Ectopic expression of eIF4B but not its phosphorylation-deficient mutant form increased KSHV lytic gene expression and production of progeny viruses. Together, these results indicated that ORF45/RSK axis-induced eIF4B phosphorylation is involved in translational regulation and is required for optimal KSHV lytic replication.
Collapse
Affiliation(s)
- Ersheng Kuang
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306-4370
| | - Bishi Fu
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306-4370
| | - Qiming Liang
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306-4370
| | - Jinjong Myoung
- Novartis Institutes for Biomedical Research, Emeryville, California 94608-2916
| | - Fanxiu Zhu
- Department of Biological Science, The Florida State University, Tallahassee, Florida 32306-4370.
| |
Collapse
|