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Bhaduri-McIntosh S, Rousseau BA. KAP1/TRIM28 - antiviral and proviral protagonist of herpesvirus biology. Trends Microbiol 2024:S0966-842X(24)00138-0. [PMID: 38871562 DOI: 10.1016/j.tim.2024.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 05/19/2024] [Accepted: 05/21/2024] [Indexed: 06/15/2024]
Abstract
Dysregulation of the constitutive heterochromatin machinery (HCM) that silences pericentromeric regions and endogenous retroviral elements in the human genome has consequences for aging and cancer. By recruiting epigenetic regulators, Krüppel-associated box (KRAB)-associated protein 1 (KAP1/TRIM28/TIF1β) is integral to the function of the HCM. Epigenetically silencing DNA genomes of incoming herpesviruses to enforce latency, KAP1 and HCM also serve in an antiviral capacity. In addition to gene silencing, newer reports highlight KAP1's ability to directly activate cellular gene transcription. Here, we discuss the many facets of KAP1, including recent findings that unexpectedly connect KAP1 to the inflammasome, reveal KAP1 cleavage as a novel mode of regulation, and argue for a pro-herpesviral KAP1 function that ensures transition from transcription to replication of the herpesvirus genome.
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Affiliation(s)
- Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, USA; Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA.
| | - Beth A Rousseau
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL, USA
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2
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Rauch DA, Ramos PV, Khanfar M, Harding J, Joseph A, Griffith O, Griffith M, Ratner L. Single-Cell Transcriptomic Analysis of Kaposi Sarcoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.01.592010. [PMID: 38746135 PMCID: PMC11092626 DOI: 10.1101/2024.05.01.592010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Kaposi Sarcoma (KS) is a complex tumor caused by KS-associated herpesvirus 8 (KSHV). Histological analysis reveals a mixture of "spindle cells", vascular-like spaces, extravasated erythrocytes, and immune cells. In order to elucidate the infected and uninfected cell types in KS tumors, we examined skin and blood samples from twelve subjects by single cell RNA sequence analyses. Two populations of KSHV-infected cells were identified, one of which represented a proliferative fraction of lymphatic endothelial cells, and the second represented an angiogenic population of vascular endothelial tip cells. Both infected clusters contained cells expressing lytic and latent KSHV genes. Novel cellular biomarkers were identified in the KSHV infected cells, including the sodium channel SCN9A. The number of KSHV positive tumor cells was found to be in the 6% range in HIV-associated KS, correlated inversely with tumor-infiltrating immune cells, and was reduced in biopsies from HIV-negative individuals. T-cell receptor clones were expanded in KS tumors and blood, although in differing magnitudes. Changes in cellular composition in KS tumors were identified in subjects treated with antiretroviral therapy alone, or immunotherapy. These studies demonstrate the feasibility of single cell analyses to identify prognostic and predictive biomarkers. Author Summary Kaposi sarcoma (KS) is a malignancy caused by the KS-associated herpesvirus (KSHV) that causes skin lesions, and may also be found in lymph nodes, lungs, gastrointestinal tract, and other organs in immunosuppressed individuals more commonly than immunocompetent subjects. The current study examined gene expression in single cells from the tumor and blood of these subjects, and identified the characteristics of the complex mixtures of cells in the tumor. This method also identified differences in KSHV gene expression in different cell types and associated cellular genes expressed in KSHV infected cells. In addition, changes in the cellular composition could be elucidated with therapeutic interventions.
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3
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Roy A, Ghosh A. Epigenetic Restriction Factors (eRFs) in Virus Infection. Viruses 2024; 16:183. [PMID: 38399958 PMCID: PMC10892949 DOI: 10.3390/v16020183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 01/23/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
The ongoing arms race between viruses and their hosts is constantly evolving. One of the ways in which cells defend themselves against invading viruses is by using restriction factors (RFs), which are cell-intrinsic antiviral mechanisms that block viral replication and transcription. Recent research has identified a specific group of RFs that belong to the cellular epigenetic machinery and are able to restrict the gene expression of certain viruses. These RFs can be referred to as epigenetic restriction factors or eRFs. In this review, eRFs have been classified into two categories. The first category includes eRFs that target viral chromatin. So far, the identified eRFs in this category include the PML-NBs, the KRAB/KAP1 complex, IFI16, and the HUSH complex. The second category includes eRFs that target viral RNA or, more specifically, the viral epitranscriptome. These epitranscriptomic eRFs have been further classified into two types: those that edit RNA bases-adenosine deaminase acting on RNA (ADAR) and pseudouridine synthases (PUS), and those that covalently modify viral RNA-the N6-methyladenosine (m6A) writers, readers, and erasers. We delve into the molecular machinery of eRFs, their role in limiting various viruses, and the mechanisms by which viruses have evolved to counteract them. We also examine the crosstalk between different eRFs, including the common effectors that connect them. Finally, we explore the potential for new discoveries in the realm of epigenetic networks that restrict viral gene expression, as well as the future research directions in this area.
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Affiliation(s)
- Arunava Roy
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA;
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4
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Daskou M, Fotooh Abadi L, Gain C, Wong M, Sharma E, Kombe Kombe AJ, Nanduri R, Kelesidis T. The Role of the NRF2 Pathway in the Pathogenesis of Viral Respiratory Infections. Pathogens 2023; 13:39. [PMID: 38251346 PMCID: PMC10819673 DOI: 10.3390/pathogens13010039] [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: 12/05/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
In humans, acute and chronic respiratory infections caused by viruses are associated with considerable morbidity and mortality. Respiratory viruses infect airway epithelial cells and induce oxidative stress, yet the exact pathogenesis remains unclear. Oxidative stress activates the transcription factor NRF2, which plays a key role in alleviating redox-induced cellular injury. The transcriptional activation of NRF2 has been reported to affect both viral replication and associated inflammation pathways. There is complex bidirectional crosstalk between virus replication and the NRF2 pathway because virus replication directly or indirectly regulates NRF2 expression, and NRF2 activation can reversely hamper viral replication and viral spread across cells and tissues. In this review, we discuss the complex role of the NRF2 pathway in the regulation of the pathogenesis of the main respiratory viruses, including coronaviruses, influenza viruses, respiratory syncytial virus (RSV), and rhinoviruses. We also summarize the scientific evidence regarding the effects of the known NRF2 agonists that can be utilized to alter the NRF2 pathway.
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Affiliation(s)
- Maria Daskou
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Leila Fotooh Abadi
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (L.F.A.); (R.N.)
| | - Chandrima Gain
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Michael Wong
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Eashan Sharma
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Arnaud John Kombe Kombe
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (L.F.A.); (R.N.)
| | - Ravikanth Nanduri
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (L.F.A.); (R.N.)
| | - Theodoros Kelesidis
- Department of Medicine, Division of Infectious Diseases, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
- Department of Internal Medicine, Division of Infectious Diseases and Geographic Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (L.F.A.); (R.N.)
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5
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Xu H, Akinyemi IA, Haley J, McIntosh MT, Bhaduri-McIntosh S. ATM, KAP1 and the Epstein-Barr virus polymerase processivity factor direct traffic at the intersection of transcription and replication. Nucleic Acids Res 2023; 51:11104-11122. [PMID: 37852757 PMCID: PMC10639065 DOI: 10.1093/nar/gkad823] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/09/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
The timing of transcription and replication must be carefully regulated for heavily-transcribed genomes of double-stranded DNA viruses: transcription of immediate early/early genes must decline as replication ramps up from the same genome-ensuring efficient and timely replication of viral genomes followed by their packaging by structural proteins. To understand how the prototypic DNA virus Epstein-Barr virus tackles the logistical challenge of switching from transcription to DNA replication, we examined the proteome at viral replication forks. Specifically, to transition from transcription, the viral DNA polymerase-processivity factor EA-D is SUMOylated by the epigenetic regulator and E3 SUMO-ligase KAP1/TRIM28. KAP1's SUMO2-ligase function is triggered by phosphorylation via the PI3K-related kinase ATM and the RNA polymerase II-associated helicase RECQ5 at the transcription machinery. SUMO2-EA-D then recruits the histone loader CAF1 and the methyltransferase SETDB1 to silence the parental genome via H3K9 methylation, prioritizing replication. Thus, a key viral protein and host DNA repair, epigenetic and transcription-replication interference pathways orchestrate the handover from transcription-to-replication, a fundamental feature of DNA viruses.
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Affiliation(s)
- Huanzhou Xu
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
| | - Ibukun A Akinyemi
- Child Health Research Institute, Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
| | - John Haley
- Department of Pathology and Stony Brook Proteomics Center, Stony Brook University, Stony Brook, NY 11794, USA
| | - Michael T McIntosh
- Child Health Research Institute, Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
| | - Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL 32610, USA
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6
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Arena A, Di Crosta M, Gonnella R, Zarrella R, Romeo MA, Benedetti R, Gilardini Montani MS, Santarelli R, D'Orazi G, Cirone M. NFE2L2 and STAT3 Converge on Common Targets to Promote Survival of Primary Lymphoma Cells. Int J Mol Sci 2023; 24:11598. [PMID: 37511362 PMCID: PMC10380615 DOI: 10.3390/ijms241411598] [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: 06/28/2023] [Revised: 07/07/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
NFE2L2 and STAT3 are key pro-survival molecules, and thus, their targeting may represent a promising anti-cancer strategy. In this study, we found that a positive feedback loop occurred between them and provided evidence that their concomitant inhibition efficiently impaired the survival of PEL cells, a rare, aggressive B cell lymphoma associated with the gammaherpesvirus KSHV and often also EBV. At the molecular level, we found that NFE2L2 and STAT3 converged in the regulation of several pro-survival molecules and in the activation of processes essential for the adaption of lymphoma cells to stress. Among those, STAT3 and NFE2L2 promoted the activation of pathways such as MAPK3/1 and MTOR that positively regulate protein synthesis, sustained the antioxidant response, expression of molecules such as MYC, BIRC5, CCND1, and HSP, and allowed DDR execution. The findings of this study suggest that the concomitant inhibition of NFE2L2 and STAT3 may be considered a therapeutic option for the treatment of this lymphoma that poorly responds to chemotherapies.
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Affiliation(s)
- Andrea Arena
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Michele Di Crosta
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Roberta Gonnella
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Roberta Zarrella
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Maria Anele Romeo
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Rossella Benedetti
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | | | - Roberta Santarelli
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
| | - Gabriella D'Orazi
- Department of Neurosciences, Imaging and Clinical Sciences, University "G. D'Annunzio", 66013 Chieti, Italy
| | - Mara Cirone
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
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7
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Schulz TF, Freise A, Stein SC. Kaposi sarcoma-associated herpesvirus latency-associated nuclear antigen: more than a key mediator of viral persistence. Curr Opin Virol 2023; 61:101336. [PMID: 37331160 DOI: 10.1016/j.coviro.2023.101336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 05/03/2023] [Accepted: 05/22/2023] [Indexed: 06/20/2023]
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus-8, is an oncogenic herpesvirus. Its latency-associated nuclear antigen (LANA) is essential for the persistence of KSHV in latently infected cells. LANA mediates replication of the latent viral genome during the S phase of a dividing cell and partitions episomes to daughter cells by attaching them to mitotic chromosomes. It also mediates the establishment of latency in newly infected cells through epigenetic mechanisms and suppresses the activation of the productive replication cycle. Furthermore, LANA promotes the proliferation of infected cell by acting as a transcriptional regulator and by modulating the cellular proteome through the recruitment of several cellular ubiquitin ligases. Finally, LANA interferes with the innate and adaptive immune system to facilitate the immune escape of infected cells.
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Affiliation(s)
- Thomas F Schulz
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany; German Center for Infection Research, Hannover-Braunschweig Site, Germany.
| | - Anika Freise
- Institute of Virology, Hannover Medical School, Germany
| | - Saskia C Stein
- Institute of Virology, Hannover Medical School, Germany; Cluster of Excellence 2155 RESIST, Germany
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8
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Huang B, Shi M, Pang A, Tan B, Xie S. Effects of Fishmeal Replacement by Clostridium Autoethanogenum Protein Meal on Cholesterol Bile Acid Metabolism, Antioxidant Capacity, Hepatic and Intestinal Health of Pearl Gentian Grouper ( Epinephelus Fuscoguttatus ♀ × Epinephelus Lanceolatus ♂). Animals (Basel) 2023; 13:ani13061090. [PMID: 36978631 PMCID: PMC10044235 DOI: 10.3390/ani13061090] [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: 01/20/2023] [Revised: 03/07/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023] Open
Abstract
In this study, we present data from an eight-week growth trial with pearl gentian grouper fed either a reference diet (FM) with a fishmeal level of 50%, or test diet wherein 15% (CAP15), 30% (CAP30), 45% (CAP45), and 60% (CAP60) fishmeal was replaced by Clostridium autoethanogenum protein meal (CAP). Results showed that the weight gain and daily feed intake ratio of CAP60 were significantly lower than the FM group. In the serum, compared to the FM group, the content of malondialdehyde (MDA), the activities of alanine aminotransferase in CAP60 and CAP45 groups, and acid phosphatase in the CAP60 group were significantly higher, while the content of total cholesterol in CAP60 and CAP45 groups was significantly lower. In the liver, compared to the control group, the content of MDA in the CAP60 group was significantly higher. 3-hydroxy-3-methylglutaryl coenzyme A reductase in CAP30 to CAP60 groups and farnesoid X receptor in CAP60 were significantly upregulated. In distal intestines, the activities of trypsin and superoxide dismutase of CAP30 to CAP60 groups were significantly lower than the FM group. In conclusion, for pearl gentian grouper, CAP could replace up to 45% of the fishmeal in the feed, while a 60% replacement level will affect cholesterol bile acid metabolism and health.
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Affiliation(s)
- Bocheng Huang
- Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
| | - Menglin Shi
- Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
| | - Aobo Pang
- Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
| | - Beiping Tan
- Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
- Aquatic Animals Precision Nutrition and High-Efficiency Feed Engineering Research Centre of Guangdong Province, Zhanjiang 524088, China
- Key Laboratory of Aquatic, Livestock and Poultry Feed Science and Technology in South China, Ministry of Agriculture, Zhanjiang 524088, China
| | - Shiwei Xie
- Laboratory of Aquatic Animal Nutrition and Feed, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China
- Aquatic Animals Precision Nutrition and High-Efficiency Feed Engineering Research Centre of Guangdong Province, Zhanjiang 524088, China
- Key Laboratory of Aquatic, Livestock and Poultry Feed Science and Technology in South China, Ministry of Agriculture, Zhanjiang 524088, China
- Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, Zhanjiang 524088, China
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9
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Preparation and characterization of magnetic PEG-PEI-PLA-PEI-PEG/FeO4-PCL/DNA micelles for gene delivery into MCF-7 cells. J Drug Deliv Sci Technol 2022. [DOI: 10.1016/j.jddst.2022.104016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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MicroRNA let-7 and viral infections: focus on mechanisms of action. Cell Mol Biol Lett 2022; 27:14. [PMID: 35164678 PMCID: PMC8853298 DOI: 10.1186/s11658-022-00317-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/26/2022] [Indexed: 02/06/2023] Open
Abstract
MicroRNAs (miRNAs) are fundamental post-transcriptional modulators of several critical cellular processes, a number of which are involved in host defense mechanisms. In particular, miRNA let-7 functions as an essential regulator of the function and differentiation of both innate and adaptive immune cells. Let-7 is involved in several human diseases, including cancer and viral infections. Several viral infections have found ways to dysregulate the expression of miRNAs. Extracellular vesicles (EV) are membrane-bound lipid structures released from many types of human cells that can transport proteins, lipids, mRNAs, and miRNAs, including let-7. After their release, EVs are taken up by the recipient cells and their contents released into the cytoplasm. Let-7-loaded EVs have been suggested to affect cellular pathways and biological targets in the recipient cells, and can modulate viral replication, the host antiviral response, and the action of cancer-related viruses. In the present review, we summarize the available knowledge concerning the expression of let-7 family members, functions, target genes, and mechanistic involvement in viral pathogenesis and host defense. This may provide insight into the development of new therapeutic strategies to manage viral infections.
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Wang Y, Ma G, Wang XF, Na L, Guo X, Zhang J, Liu C, Du C, Qi T, Lin Y, Wang X. Keap1 recognizes EIAV early accessory protein Rev to promote antiviral defense. PLoS Pathog 2022; 18:e1009986. [PMID: 35139135 PMCID: PMC8863222 DOI: 10.1371/journal.ppat.1009986] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/22/2022] [Accepted: 01/13/2022] [Indexed: 12/17/2022] Open
Abstract
The Nrf2/Keap1 axis plays a complex role in viral susceptibility, virus-associated inflammation and immune regulation in host cells. However, whether or how the Nrf2/Keap1 axis is involved in the interactions between equine lentiviruses and their hosts remains unclear. Here, we demonstrate that the Nrf2/Keap1 axis was activated during EIAV infection. Mechanistically, EIAV-Rev competitively binds to Keap1 and releases Nrf2 from Keap1-mediated repression, leading to the accumulation of Nrf2 in the nucleus and promoting Nrf2 responsive genes transcription. Subsequently, we demonstrated that the Nrf2/Keap1 axis represses EIAV replication via two independent molecular mechanisms: directly increasing antioxidant enzymes to promote effective cellular resistance against EIAV infection, and repression of Rev-mediated RNA transport through direct interaction between Keap1 and Rev. Together, these data suggest that activation of the Nrf2/Keap1 axis mediates a passive defensive response to combat EIAV infection. The Nrf2/Keap1 axis could be a potential target for developing strategies for combating EIAV infection.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Guanqin Ma
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xue-Feng Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Lei Na
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xing Guo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Jiaqi Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Cong Liu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Cheng Du
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Ting Qi
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Yuezhi Lin
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Xiaojun Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
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12
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Sandhu PK, Damania B. The regulation of KSHV lytic reactivation by viral and cellular factors. Curr Opin Virol 2022; 52:39-47. [PMID: 34872030 PMCID: PMC8844089 DOI: 10.1016/j.coviro.2021.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 11/03/2021] [Indexed: 02/03/2023]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic herpesvirus that exhibits two distinct phases of infection in the host-latent and lytic. The quiescent latent phase is defined by limited expression of a subset of viral proteins and microRNAs, and an absence of virus production. KSHV periodically reactivates from latency to undergo active lytic replication, leading to production of new infectious virions. This switch from the latent to the lytic phase requires the viral protein regulator of transcription activator (RTA). RTA, along with other virally encoded proteins, is aided by host factors to facilitate this transition. Herein, we highlight the key host proteins that are involved in mediating RTA activation and KSHV lytic replication and discuss the cellular processes in which they function. We will also focus on the modulation of viral reactivation by the innate immune system, and how KSHV influences key immune signaling pathways to aid its own lifecycle.
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Affiliation(s)
- Praneet Kaur Sandhu
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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13
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Di C, Zheng G, Zhang Y, Tong E, Ren Y, Hong Y, Song Y, Chen R, Tan X, Yang L. RTA and LANA Competitively Regulate let-7a/RBPJ Signal to Control KSHV Replication. Front Microbiol 2022; 12:804215. [PMID: 35069510 PMCID: PMC8777081 DOI: 10.3389/fmicb.2021.804215] [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: 10/29/2021] [Accepted: 12/03/2021] [Indexed: 11/13/2022] Open
Abstract
The recombination signal binding protein for immunoglobulin kappa J region (RBPJ) has a dual effect on Kaposi's sarcoma-associated herpesvirus (KSHV) replication. RBPJ interaction with replication and transcription activator (RTA) is essential for lytic replication, while the interaction with latency-associated nuclear antigen (LANA) facilitates latent infection. Furthermore, our previous study found that LANA decreased RBPJ through upregulating miRNA let-7a. However, it is unclear whether RTA regulates the expression of RBPJ. Here, we show RTA increases RBPJ by decreasing let-7a. During KSHV replication, the RBPJ expression level was positively correlated with the RTA expression level and negatively correlated with the LANA expression level. The let-7a expression level was inverse to RBPJ. Knockdown of RBPJ inhibited the self-activation of RTA promoter and LANA promoter and weakened LANA's inhibition of RTA promoter. Collectively, these findings indicate that RTA and LANA compete for let-7a/RBPJ signal to control the KSHV replication. Regulating the RBPJ expression level by RTA and LANA plays an important role during KSHV replication.
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Affiliation(s)
- Chunhong Di
- Affiliated Hospital, Hangzhou Normal University, Hangzhou, China.,School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Guoxia Zheng
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yunheng Zhang
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Enyu Tong
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yanli Ren
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yu Hong
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Yang Song
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Rong Chen
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Xiaohua Tan
- School of Public Health, Hangzhou Normal University, Hangzhou, China
| | - Lei Yang
- School of Public Health, Hangzhou Normal University, Hangzhou, China
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NRF2 in Viral Infection. Antioxidants (Basel) 2021; 10:antiox10091491. [PMID: 34573123 PMCID: PMC8472116 DOI: 10.3390/antiox10091491] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/15/2021] [Accepted: 09/16/2021] [Indexed: 12/29/2022] Open
Abstract
The transcription factor NRF2 is central to redox homeostasis in animal cells and is a well-known driver of chemoresistance in many types of cancer. Recently, new roles have been ascribed to NRF2 which include regulation of antiviral interferon responses and inflammation. In addition, NRF2 is emerging as an important factor in antiviral immunity through interferon-independent mechanisms. In the review, we give an overview of the scientific progress on the involvement and importance of NRF2 in the context of viral infection.
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Inflammasome, the Constitutive Heterochromatin Machinery, and Replication of an Oncogenic Herpesvirus. Viruses 2021; 13:v13050846. [PMID: 34066537 PMCID: PMC8148530 DOI: 10.3390/v13050846] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 05/01/2021] [Accepted: 05/03/2021] [Indexed: 02/07/2023] Open
Abstract
The success of long-term host–virus partnerships is predicated on the ability of the host to limit the destructive potential of the virus and the virus’s skill in manipulating its host to persist undetected yet replicate efficiently when needed. By mastering such skills, herpesviruses persist silently in their hosts, though perturbations in this host–virus equilibrium can result in disease. The heterochromatin machinery that tightly regulates endogenous retroviral elements and pericentromeric repeats also silences invading genomes of alpha-, beta-, and gammaherpesviruses. That said, how these viruses disrupt this constitutive heterochromatin machinery to replicate and spread, particularly in response to disparate lytic triggers, is unclear. Here, we review how the cancer-causing gammaherpesvirus Epstein–Barr virus (EBV) uses the inflammasome as a security system to alert itself of threats to its cellular home as well as to flip the virus-encoded lytic switch, allowing it to replicate and escape in response to a variety of lytic triggers. EBV provides the first example of an infectious agent able to actively exploit the inflammasome to spark its replication. Revealing an unexpected link between the inflammasome and the epigenome, this further brings insights into how the heterochromatin machinery uses differential strategies to maintain the integrity of the cellular genome whilst guarding against invading pathogens. These recent insights into EBV biology and host–viral epigenetic regulation ultimately point to the NLRP3 inflammasome as an attractive target to thwart herpesvirus reactivation.
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Freeborn RA, Rockwell CE. The role of Nrf2 in autoimmunity and infectious disease: Therapeutic possibilities. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2021; 91:61-110. [PMID: 34099113 DOI: 10.1016/bs.apha.2020.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Nrf2 is a cytoprotective transcription factor which is involved in ameliorating oxidative stress and toxic insults. Recently, an immunomodulatory role for Nrf2 has gained appreciation as it has been shown to protect cells and hosts alike in a variety of immune and inflammatory disorders. However, Nrf2 utilizes numerous distinct pathways to elicit its immunomodulatory effects. In this review, we summarize the literature discussing the roles of Nrf2 in autoimmunity and infectious diseases with a goal of understanding the potential to therapeutically target Nrf2.
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Affiliation(s)
- Robert A Freeborn
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States
| | - Cheryl E Rockwell
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, United States; Institute for Integrative Toxicology, Michigan State University, East Lansing, MI, United States; Cell and Molecular Biology Program, Michigan State University, East Lansing, MI, United States.
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Kaposi's Sarcoma-Associated Herpesvirus LANA Modulates the Stability of the E3 Ubiquitin Ligase RLIM. J Virol 2020; 94:JVI.01578-19. [PMID: 31801865 DOI: 10.1128/jvi.01578-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 11/26/2019] [Indexed: 11/20/2022] Open
Abstract
The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded latency-associated nuclear antigen (LANA) protein functions in latently infected cells as an essential participant in KSHV genome replication and as a driver of dysregulated cell growth. In a previous study, we have identified LANA-interacting proteins using a protein array screen. Here, we explore the effect of LANA on the stability and activity of RLIM (RING finger LIM-domain-interacting protein, encoded by the RNF12 gene), a novel LANA-interacting protein identified in that protein screen. RLIM is an E3 ubiquitin ligase that leads to the ubiquitination and degradation of several transcription regulators, such as LMO2, LMO4, LHX2, LHX3, LDB1, and the telomeric protein TRF1. Expression of LANA leads to downregulation of RLIM protein levels. This LANA-mediated RLIM degradation is blocked in the presence of the proteasome inhibitor, MG132. Therefore, the interaction between LANA and RLIM could be detected in coimmunoprecipitation assay only in the presence of MG132 to prevent RLIM degradation. A RING finger mutant RLIM is resistant to LANA-mediated degradation, suggesting that LANA promotes RLIM autoubiquitination. Interestingly, we found that LANA enhanced the degradation of some RLIM substrates, such as LDB1 and LMO2, and prevented RLIM-mediated degradation of others, such as LHX3 and TRF1. We also show that transcription regulation by RLIM substrates is modulated by LANA. RLIM substrates are assembled into multiprotein transcription regulator complexes that regulate the expression of many cellular genes. Therefore, our study identified another way KSHV can modulate cellular gene expression.IMPORTANCE E3 ubiquitin ligases mark their substrates for degradation and therefore control the cellular abundance of their substrates. RLIM is an E3 ubiquitin ligase that leads to the ubiquitination and degradation of several transcription regulators, such as LMO2, LMO4, LHX2, LHX3, LDB1, and the telomeric protein TRF1. Here, we show that the Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded LANA protein enhances the ubiquitin ligase activity of RLIM, leading to enhanced RLIM autoubiquitination and degradation. Interestingly, LANA enhanced the degradation of some RLIM substrates, such as LDB1 and LMO2, and prevented RLIM-mediated degradation of others, such as LHX3 and TRF1. In agreement with protein stability of RLIM substrates, we found that LANA modulates transcription by LHX3-LDB1 complex and suggest additional ways LANA can modulate cellular gene expression. Our study adds another way a viral protein can regulate cellular protein stability, by enhancing the autoubiquitination and degradation of an E3 ubiquitin ligase.
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18
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Kays JS, Yamamoto BK. Evaluation of Microglia/Macrophage Cells from Rat Striatum and Prefrontal Cortex Reveals Differential Expression of Inflammatory-Related mRNA after Methamphetamine. Brain Sci 2019; 9:brainsci9120340. [PMID: 31775383 PMCID: PMC6955783 DOI: 10.3390/brainsci9120340] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/19/2019] [Accepted: 11/20/2019] [Indexed: 12/19/2022] Open
Abstract
RNA sequencing (RNAseq) can be a powerful tool in the identification of transcriptional changes after drug treatment. RNAseq was utilized to determine expression changes in Fluorescence-activated cell sorted (FACS) CD11b/c+ cells from the striatum (STR) and prefrontal cortex (PFC) of male Sprague-Dawley rats after a methamphetamine (METH) binge dosing regimen. Resident microglia and infiltrating macrophages were collected 2 h or 3 days after drug administration. Gene expression changes indicated there was an increase toward an overall pro-inflammatory state, or M1 polarization, along with what appears to be a subset of cells that differentiated toward the anti-inflammatory M2 polarization. In general, there were significantly more mRNA expression changes in the STR than the PFC and more at 2 h post-binge METH than at 3 days post-binge METH. Additionally, Ingenuity® Pathway Analysis along with details of RNA expression changes revealed cyclo-oxygenase 2 (COX2)-driven prostaglandin (PG) E2 synthesis, glutamine uptake, and the Nuclear factor erythroid2-related factor 2 (NRF2) canonical pathway in microglia were associated with the binge administration regimen of METH.
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19
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HACE1, an E3 Ubiquitin Protein Ligase, Mitigates Kaposi's Sarcoma-Associated Herpesvirus Infection-Induced Oxidative Stress by Promoting Nrf2 Activity. J Virol 2019; 93:JVI.01812-18. [PMID: 30787155 DOI: 10.1128/jvi.01812-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 02/12/2019] [Indexed: 12/14/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV)-induced activation of nuclear factor erythroid 2-related factor 2 (Nrf2) is essential for both the expression of viral genes (latency) and modulation of the host antioxidant machinery. Reactive oxygen species (ROS) are also regulated by the ubiquitously expressed HACE1 protein (HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1), which targets the Rac1 protein for proteasomal degradation, and this blocks the generation of ROS by Rac1-dependent NADPH oxidases. In this study, we examined the role of HACE1 in KSHV infection. Elevated levels of HACE1 expression were observed in de novo KSHV-infected endothelial cells, KSHV latently infected TIVE-LTC and PEL cells, and Kaposi's sarcoma skin lesion cells. The increased HACE1 expression in the infected cells was mediated by KSHV latent protein kaposin A. HACE1 knockdown resulted in high Rac1 and Nox 1 (NADPH oxidase 1) activity, increased ROS (oxidative stress), increased cell death, and decreased KSHV gene expression. Loss of HACE1 impaired KSHV infection-induced phosphoinositide 3-kinase (PI3-K), protein kinase C-ζ (PKC-ζ), extracellular signal-regulated kinase 1/2 (ERK1/2), NF-κB, and Nrf2 activation and nuclear translocation of Nrf2, and it reduced the expression of Nrf2 target genes responsible for balancing the oxidative stress. In the absence of HACE1, glutamine uptake increased in the cells to cope with the KSHV-induced oxidative stress. These findings reveal for the first time that HACE1 plays roles during viral infection-induced oxidative stress and demonstrate that HACE1 facilitates resistance to KSHV infection-induced oxidative stress by promoting Nrf2 activity. Our studies suggest that HACE1 could be a potential target to induce cell death in KSHV-infected cells and to manage KSHV infections.IMPORTANCE ROS play important roles in several cellular processes, and increased ROS cause several adverse effects. KSHV infection of endothelial cells induces ROS, which facilitate virus entry by amplifying the infection-induced host cell signaling cascade, which, in turn, induces the nuclear translocation of phospho-Nrf2 protein to regulate the expression of antioxidative genes and viral genes. The present study demonstrates that KSHV infection induces the E3 ligase HACE1 protein to regulate KSHV-induced oxidative stress by promoting the activation of Nrf2 and nuclear translocation. Absence of HACE1 results in increased ROS and cellular death and reduced nuclear Nrf2, antioxidant, and viral gene expression. Together, these studies suggest that HACE1 can be a potential target to induce cell death in KSHV-infected cells.
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20
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Butnaru M, Gaglia MM. Transcriptional and post-transcriptional regulation of viral gene expression in the gamma-herpesvirus Kaposi's sarcoma-associated herpesvirus. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019; 5:219-228. [PMID: 30854283 DOI: 10.1007/s40588-018-0102-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Purpose of review Kaposi's sarcoma-associated herpesvirus (KSHV), the etiological agent of the AIDS-associated tumor Kaposi's sarcoma, is a complex virus that expresses ~90 proteins in a regulated temporal cascade during its replication cycle. Although KSHV relies on cellular machinery for gene expression, it also uses specialized regulators to control nearly every step of the process. In this review we discuss the current understanding of KSHV gene regulation. Recent findings High-throughput sequencing and a new robust system to mutate KSHV have paved the way for comprehensive studies of KSHV gene expression, leading to the characterization of new viral factors that control late gene expression and post-transcriptional steps of gene regulation. They have also revealed key aspects of chromatin-based control of gene expression in the latent and lytic cycle. Summary The combination of mutant analysis and high-throughput sequencing will continue to expand our model of KSHV gene regulation and point to potential new targets for anti-KSHV drugs.
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Affiliation(s)
- Matthew Butnaru
- Graduate Program in Biochemistry, Sackler School of Biomedical Sciences, Tufts University, Boston, MA, USA
- Department of Molecular Biology and Microbiology, School of Medicine, Tufts University, Boston, MA, USA
| | - Marta M Gaglia
- Department of Molecular Biology and Microbiology, School of Medicine, Tufts University, Boston, MA, USA
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21
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Qi Y, Zheng G, Di C, Zhang J, Wang X, Hong Y, Song Y, Chen R, Yang Y, Yan Y, Xu L, Tan X, Yang L. Latency-associated nuclear antigen inhibits lytic replication of Kaposi's sarcoma-associated herpesvirus by regulating let-7a/RBPJ signaling. Virology 2019; 531:69-78. [PMID: 30856484 DOI: 10.1016/j.virol.2019.02.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/27/2019] [Accepted: 02/27/2019] [Indexed: 10/27/2022]
Abstract
Latency-associated nuclear antigen (LANA) is the key factor in the establishment and maintenance of latency of Kaposi's sarcoma-associated herpesvirus (KSHV). A cellular protein, recombination signal binding protein for immunoglobulin kappa J region (RBPJ), is essential for the lytic reactivation of KSHV. However, whether RBPJ expression is regulated by KSHV is not clear. Here, we show that LANA upregulates let-7a and its primary transcripts in parallel with its reduction of RBPJ expression. An increase in notch intracellular domain (NICD) and the downregulation of NF-κB and LIN28B contribute to the upregulation of let-7a by LANA. Let-7a represses RBPJ expression by directly binding the 3' untranslated region of RBPJ. Let-7a overexpression or RBPJ knockdown led to a dose- and time-dependent inhibition of lytic reactivation of KSHV. Collectively, these findings support a model wherein LANA inhibits the lytic replication of KSHV by regulating let-7a/RBPJ signaling.
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Affiliation(s)
- Yan Qi
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Guoxia Zheng
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Chunhong Di
- Affiliated Hospital, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Jinxia Zhang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Xiaobo Wang
- Affiliated Hospital, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Yu Hong
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Yang Song
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Rong Chen
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Yi Yang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Yutao Yan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Liangwen Xu
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China
| | - Xiaohua Tan
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
| | - Lei Yang
- School of Medicine, Hangzhou Normal University, Hangzhou, Zhejiang, People's Republic of China.
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22
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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.
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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.
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Gilardini Montani MS, Santarelli R, Granato M, Gonnella R, Torrisi MR, Faggioni A, Cirone M. EBV reduces autophagy, intracellular ROS and mitochondria to impair monocyte survival and differentiation. Autophagy 2018; 15:652-667. [PMID: 30324853 DOI: 10.1080/15548627.2018.1536530] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
EBV has been reported to impair monocyte in vitro differentiation into dendritic cells (DCs) and reduce cell survival. In this study, we added another layer of knowledge to this topic and showed that these effects correlated with macroautophagy/autophagy, ROS and mitochondrial biogenesis reduction. Of note, autophagy and ROS, although strongly interconnected, have been separately reported to be induced by CSF2/GM-CSF (colony stimulating factor 2) and required for CSF2-IL4-driven monocyte in vitro differentiation into DCs. We show that EBV infects monocytes and initiates a feedback loop in which, by inhibiting autophagy, reduces ROS and through ROS reduction negatively influences autophagy. Mechanistically, autophagy reduction correlated with the downregulation of RAB7 and ATG5 expression and STAT3 activation, leading to the accumulation of SQSTM1/p62. The latter activated the SQSTM1-KEAP1- NFE2L2 axis and upregulated the anti-oxidant response, reducing ROS and further inhibiting autophagy. ROS decrease correlated also with the reduction of mitochondria, the main source of intracellular ROS, achieved by the downregulation of NRF1 and TFAM, mitochondrial biogenesis transcription factors. Interestingly, mitochondria supply membranes and ATP required for autophagy execution, thus their reduction may further reduce autophagy in EBV-infected monocytes. In conclusion, this study shows for the first time that the interconnected reduction of autophagy, intracellular ROS and mitochondria mediated by EBV switches monocyte differentiation into apoptosis, giving new insights into the mechanisms through which this virus reduces immune surveillance. Abbreviations: ACTB: actin beta; ATG5: autophagy related 5; BAF: bafilomycin A1; BECN1: beclin 1; CAT: catalase; CSF2: colony stimulating factor 2; CT: control; CYCS (cytochrome C: somatic); DCs: dendritic cells; EBV: Epstein-Barr virus; GSR: glutathione-disulfide reductase; KEAP1: kelch like ECH associated protein 1; IL4: interleukin 4; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MET: metformin; NAC: N-acetylcysteine; NFE2L2/NRF2 nuclear factor: erythroid 2 like 2; NRF1 (nuclear respiratory factor 1); clPARP1: cleaved poly(ADP-ribose) polymerase; Rapa: Rapamycin; ROS: reactive oxygen species; SQSTM1/p62: sequestosome 1; TFAM: (transcription factor A: mitochondrial); TUBA1A: tubulin alpha 1a.
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Affiliation(s)
- M S Gilardini Montani
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
| | - R Santarelli
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
| | - M Granato
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
| | - R Gonnella
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
| | - M R Torrisi
- b Department of Clinical and Molecular Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Italy.,c Sant'Andrea University Hospital , Azienda Ospedaliera Sant'Andrea , Rome , Italy
| | - A Faggioni
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
| | - M Cirone
- a Department of Experimental Medicine , Sapienza University of Rome, laboratory affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti , Rome , Italy
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KRAB-ZFP Repressors Enforce Quiescence of Oncogenic Human Herpesviruses. J Virol 2018; 92:JVI.00298-18. [PMID: 29695433 DOI: 10.1128/jvi.00298-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/21/2018] [Indexed: 12/15/2022] Open
Abstract
Cancer-causing herpesviruses infect nearly every human and persist indefinitely in B lymphocytes in a quiescent state known as latency. A hallmark of this quiescence or latency is the presence of extrachromosomal viral genomes with highly restricted expression of viral genes. Silencing of viral genes ensures both immune evasion by the virus and limited pathology to the host, yet how multiple genes on multiple copies of viral genomes are simultaneously silenced is a mystery. In a unifying theme, we report that both cancer-causing human herpesviruses, despite having evolved independently, are silenced through the activities of two members of the Krüppel-associated box (KRAB) domain-zinc finger protein (ZFP) (KRAB-ZFP) epigenetic silencing family, revealing a novel STAT3-KRAB-ZFP axis of virus latency. This dual-edged antiviral strategy restricts the destructive ability of the lytic phase while promoting the cancer-causing latent phase. These findings also unveil roles for KRAB-ZFPs in silencing of multicopy foreign genomes with the promise of evicting herpesviruses to kill viral cancers bearing clonal viral episomes.IMPORTANCE Despite robust immune responses, cancer-causing viruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) persist for life. This persistence is accomplished partly through a stealth mechanism that keeps extrachromosomal viral genomes quiescent. Quiescence, or latency, ensures that not every cell harboring viral genomes is killed directly through lytic activation or indirectly via the immune response, thereby evicting virus from host. For the host, quiescence limits pathology. Thus, both virus and host benefit from quiescence, yet how quiescence is maintained through silencing of a large set of viral genes on multiple viral genomes is not well understood. Our studies reveal that members of a gene-silencing family, the KRAB-ZFPs, promote quiescence of both cancer-causing human viruses through simultaneous silencing of multiple genes on multicopy extrachromosomal viral genomes.
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25
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Ramezani A, Nahad MP, Faghihloo E. The role of Nrf2 transcription factor in viral infection. J Cell Biochem 2018; 119:6366-6382. [DOI: 10.1002/jcb.26897] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 03/28/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Ali Ramezani
- Virology DepartmentSchool of MedicineAhvaz Jundishapur University of Medical SciencesAhvazIran
- Hepatitis Research CenterBirjand University of Medical SciencesBirjandIran
| | - Mehdi Parsa Nahad
- Virology DepartmentSchool of MedicineAhvaz Jundishapur University of Medical SciencesAhvazIran
| | - Ebrahim Faghihloo
- Department of MicrobiologySchool of MedicineShahid Beheshti University of Medical SciencesTehranIran
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26
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Lv DW, Zhang K, Li R. Interferon regulatory factor 8 regulates caspase-1 expression to facilitate Epstein-Barr virus reactivation in response to B cell receptor stimulation and chemical induction. PLoS Pathog 2018; 14:e1006868. [PMID: 29357389 PMCID: PMC5794192 DOI: 10.1371/journal.ppat.1006868] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/01/2018] [Accepted: 01/09/2018] [Indexed: 12/30/2022] Open
Abstract
Interferon regulatory factor 8 (IRF8), also known as interferon consensus sequence-binding protein (ICSBP), is a transcription factor of the IRF family. IRF8 plays a key role in normal B cell differentiation, a cellular process that is intrinsically associated with Epstein-Barr virus (EBV) reactivation. However, whether IRF8 regulates EBV lytic replication remains unknown. In this study, we utilized a CRISPR/Cas9 genomic editing approach to deplete IRF8 and found that IRF8 depletion dramatically inhibits the reactivation of EBV upon lytic induction. We demonstrated that IRF8 depletion suppresses the expression of a group of genes involved in apoptosis and thus inhibits apoptosis induction upon lytic induction by B cell receptor (BCR) stimulation or chemical induction. The protein levels of caspase-1, caspase-3 and caspase-8 all dramatically decreased in IRF8-depleted cells, which led to reduced caspase activation and the stabilization of KAP1, PAX5 and DNMT3A upon BCR stimulation. Interestingly, caspase inhibition blocked the degradation of KAP1, PAX5 and DNMT3A, suppressed EBV lytic gene expression and viral DNA replication upon lytic induction, suggesting that the reduced caspase expression in IRF8-depleted cells contributes to the suppression of EBV lytic replication. We further demonstrated that IRF8 directly regulates CASP1 (caspase-1) gene expression through targeting its gene promoter and knockdown of caspase-1 abrogates EBV reactivation upon lytic induction, partially through the stabilization of KAP1. Together our study suggested that, by modulating the activation of caspases and the subsequent cleavage of KAP1 upon lytic induction, IRF8 plays a critical role in EBV lytic reactivation. Infection with Epstein-Barr virus (EBV) is closely associated with human cancers of both B cell and epithelial cell origin. The EBV life cycle is tightly regulated by both viral and cellular factors. Here, we demonstrate that interferon regulatory factor 8 (IRF8) is required for EBV lytic replication. Mechanistically, IRF8 directly regulates caspase-1 expression and hence caspase activation upon B cell receptor (BCR) stimulation and chemical induction, which leads to the cleavage and de-stabilization of several host factors suppressing lytic replication, including KAP1. Caspase-1 depletion blocks EBV reactivation while KAP1 depletion facilitates reactivation in caspase-1 depleted cells. These results together establish a IRF8/caspase-1/KAP1 axis important for EBV reactivation.
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Affiliation(s)
- Dong-Wen Lv
- Department of Oral and Craniofacial Molecular Biology and Philips Institute for Oral Health Research, School of Dentistry, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kun Zhang
- Department of Oral and Craniofacial Molecular Biology and Philips Institute for Oral Health Research, School of Dentistry, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Renfeng Li
- Department of Oral and Craniofacial Molecular Biology and Philips Institute for Oral Health Research, School of Dentistry, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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Abstract
Viral latency can be considered a metastable, nonproductive infection state that is capable of subsequent reactivation to repeat the infection cycle. Viral latent infections have numerous associated pathologies, including cancer, birth defects, neuropathy, cardiovascular disease, chronic inflammation, and immunological dysfunctions. The mechanisms controlling the establishment, maintenance, and reactivation from latency are complex and diversified among virus families, species, and strains. Yet, as examined in this review, common properties of latent viral infections can be defined. Eradicating latent virus has become an important but elusive challenge and will require a more complete understanding of the mechanisms controlling these processes.
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Effects of the NEDD8-Activating Enzyme Inhibitor MLN4924 on Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus. J Virol 2017; 91:JVI.00505-17. [PMID: 28701396 PMCID: PMC5599746 DOI: 10.1128/jvi.00505-17] [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: 03/28/2017] [Accepted: 06/30/2017] [Indexed: 12/12/2022] Open
Abstract
The switch of Kaposi's sarcoma-associated herpesvirus (KSHV) from latency to lytic replication is a key event for viral dissemination and pathogenesis. MLN4924, a novel neddylation inhibitor, reportedly causes the onset of KSHV reactivation but impairs later phases of the viral lytic program in infected cells. Thus far, the molecular mechanism involved in the modulation of the KSHV lytic cycle by MLN4924 is not yet fully understood. Here, we confirmed that treatment of different KSHV-infected primary effusion lymphoma (PEL) cell lines with MLN4924 substantially induces viral lytic protein expression. Due to the key role of the virally encoded ORF50 protein in the latent-to-lytic switch, we investigated its transcriptional regulation by MLN4924. We found that MLN4924 activates the ORF50 promoter (ORF50p) in KSHV-positive cells (but not in KSHV-negative cells), and the RBP-Jκ-binding elements within the promoter are critically required for MLN4924 responsiveness. In KSHV-negative cells, reactivation of the ORF50 promoter by MLN4924 requires the presence of the latency-associated nuclear antigen (LANA). Under such a condition, LANA acts as a repressor to block the ORF50p activity, whereas MLN4924 treatment relieves LANA-mediated repression. Importantly, we showed that LANA is a neddylated protein and can be deneddylated by MLN4924. On the other hand, we revealed that MLN4924 exhibits concentration-dependent biphasic effects on 12-O-tetradecanoylphorbol-13-acetate (TPA)- or sodium butyrate (SB)-induced viral reactivation in PEL cell lines. In other words, low concentrations of MLN4924 promote activation of TPA- or SB-mediated viral reactivation, whereas high concentrations of MLN4924, conversely, inhibit the progression of TPA- or SB-mediated viral lytic program.IMPORTANCE MLN4924 is a neddylation (NEDD8 modification) inhibitor, which currently acts as an anti-cancer drug in clinical trials. Although MLN4924 has been reported to trigger KSHV reactivation, many aspects regarding the action of MLN4924 in regulating the KSHV lytic cycle are not fully understood. Since the KSHV ORF50 protein is the key regulator of viral lytic reactivation, we focus on its transcriptional regulation by MLN4924. We here show that activation of the ORF50 gene by MLN4924 involves the relief of LANA-mediated transcriptional repression. Importantly, we find that LANA is a neddylated protein. To our knowledge, this is the first report showing that neddylation occurs in viral proteins. Additionally, we provide evidence that different concentrations of MLN4924 have opposite effects on TPA-mediated or SB-mediated KSHV lytic cycle activation. Therefore, in clinical application, we propose that MLN4924 needs to be used with caution in combination therapy to treat KSHV-positive subjects.
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Wang Y, Li J, Huang Y, Dai X, Liu Y, Liu Z, Wang Y, Wang N, Zhang P. Tripartite motif-containing 28 bridges endothelial inflammation and angiogenic activity by retaining expression of TNFR-1 and -2 and VEGFR2 in endothelial cells. FASEB J 2017; 31:2026-2036. [PMID: 28159803 DOI: 10.1096/fj.201600988rr] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 01/17/2017] [Indexed: 11/11/2022]
Abstract
Angiogenesis and inflammation are regarded as important factors in the pathogenesis of chronic inflammation, cancer, and wound healing. Recent studies have supported prior evidence that common signaling pathways are involved in angiogenesis and inflammatory responses; however, key factors controlling both processes remain unclear. Although tripartite motif-containing (TRIM)-28 is known to have an immunosuppressive role in immune cells, its expression level and role in endothelial cells (ECs) are still unclear. In this study, we investigated the role of TRIM28 in inflammatory responses and angiogenic activity of ECs for the first time. We showed that TRIM28 is the most abundant TRIM family member and is localized in nuclei of ECs. Small interfering RNA-mediated knockdown of TRIM28 strikingly suppressed expression of TNF receptor (TNFR)-1 and -2, decreased TNF-α-induced phosphorylation of IKKα/β and IκBα and degradation of IκBα and nuclear translocation of p65, and suppressed basal level and TNF-α-induced expression of chemokines and adhesion molecules, including VCAM-1, IL-6, ICAM-1, E-selectin, and monocyte chemoattractant protein (MCP)-1. Unexpectedly, IL-8 was potentiated by TRIM28 knockdown in ECs in an NF-κB-inducing kinase-dependent manner. Meanwhile, knockdown of TRIM28 inhibited expression of VEGF receptor 2 and suppressed VEGF-induced proliferation and tube formation by ECs. Finally, knockdown of TRIM28 suppressed recruitment of ECs in vivo in a murine synthetic basement membrane model. In summary, we found that TRIM28 acts as a central factor in controlling endothelial inflammatory responses and angiogenic activities by retaining expression of TNFR-1 and -2 and VEGF receptor 2 in ECs.-Wang, Y., Li, J., Huang Y., Dai, X., Liu, Y., Liu, Z., Wang, Y., Wang, N., Zhang, P. Tripartite motif-containing 28 bridges endothelial inflammation and angiogenic activity by retaining expression of TNFR1 and -2 and VEGFR2 in endothelial cells.
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Affiliation(s)
- Yinfang Wang
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jinping Li
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yitong Huang
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Xiuqin Dai
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Youbin Liu
- Department of Cardiovascular Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Zongjun Liu
- Department of Cardiovascular Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ying Wang
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Jacksonville, Florida, USA; and
| | - Nanping Wang
- The Advanced Institute for Medical Sciences, Dalian Medical University, Dalian, China
| | - Peng Zhang
- Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China;
- Department of Cardiovascular Medicine, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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Knipe DM, Raja P, Lee J. Viral gene products actively promote latent infection by epigenetic silencing mechanisms. Curr Opin Virol 2017; 23:68-74. [PMID: 28415052 DOI: 10.1016/j.coviro.2017.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/06/2017] [Accepted: 03/16/2017] [Indexed: 12/15/2022]
Abstract
Many viruses undergo an acute infection in the host organism and then are cleared by the ensuing host immune response, but other viruses establish a persistent infection involving a latent infection or a chronic infection. Latent infection by the herpesviruses or human immunodeficiency virus involves epigenetic silencing of the DNA genome or proviral genome, respectively. Latent infection was previously thought to be a default pathway resulting from infection of a nonpermissive cell, but recent studies have shown that viral gene products can promote epigenetic silencing and latent infection. This review will summarize the viral gene products that have been shown to promote epigenetic silencing of the genomes and their potential for therapeutics to target these viral gene products and disrupt or lock in latent infection.
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Affiliation(s)
- David M Knipe
- Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, United States.
| | - Priya Raja
- Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, United States
| | - Jennifer Lee
- Department of Microbiology and Immunobiology, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, United States
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31
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Gandhi J, Khera L, Gaur N, Paul C, Kaul R. Role of Modulator of Inflammation Cyclooxygenase-2 in Gammaherpesvirus Mediated Tumorigenesis. Front Microbiol 2017; 8:538. [PMID: 28400769 PMCID: PMC5368278 DOI: 10.3389/fmicb.2017.00538] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 03/14/2017] [Indexed: 12/25/2022] Open
Abstract
Chronic inflammation is recognized as a threat factor for cancer progression. Release of inflammatory molecules generates microenvironment which is highly favorable for development of tumor, cancer progression and metastasis. In cases of latent viral infections, generation of such a microenvironment is one of the major predisposing factors related to virus mediated tumorigenesis. Among various inflammatory mediators implicated in pathological process associated with cancer, the cyclooxygenase (COX) and its downstream effector molecules are of greater significance. Though the role of infectious agents in causing inflammation leading to transformation of cells has been more or less well established, however, the mechanism by which inflammation in itself modulates the events in life cycle of infectious agent is not very much clear. This is specifically important for gammaherpesviruses infections where viral life cycle is characterized by prolonged periods of latency when the virus remains hidden, immunologically undetectable and expresses only a very limited set of genes. Therefore, it is important to understand the mechanisms for role of inflammation in virus life cycle and tumorigenesis. This review is an attempt to summarize the latest findings highlighting the significance of COX-2 and its downstream signaling effectors role in life cycle events of gammaherpesviruses leading to progression of cancer.
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Affiliation(s)
- Jaya Gandhi
- Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Lohit Khera
- Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Nivedita Gaur
- Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Catherine Paul
- Department of Microbiology, University of Delhi South Campus New Delhi, India
| | - Rajeev Kaul
- Department of Microbiology, University of Delhi South Campus New Delhi, India
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32
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Li X, Burton EM, Bhaduri-McIntosh S. Chloroquine triggers Epstein-Barr virus replication through phosphorylation of KAP1/TRIM28 in Burkitt lymphoma cells. PLoS Pathog 2017; 13:e1006249. [PMID: 28249048 PMCID: PMC5348047 DOI: 10.1371/journal.ppat.1006249] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 03/13/2017] [Accepted: 02/17/2017] [Indexed: 01/09/2023] Open
Abstract
Trials to reintroduce chloroquine into regions of Africa where P. falciparum has regained susceptibility to chloroquine are underway. However, there are long-standing concerns about whether chloroquine increases lytic-replication of Epstein-Barr virus (EBV), thereby contributing to the development of endemic Burkitt lymphoma. We report that chloroquine indeed drives EBV replication by linking the DNA repair machinery to chromatin remodeling-mediated transcriptional repression. Specifically, chloroquine utilizes ataxia telangiectasia mutated (ATM) to phosphorylate the universal transcriptional corepressor Krüppel-associated Box-associated protein 1/tripartite motif-containing protein 28 (KAP1/TRIM28) at serine 824 -a mechanism that typically facilitates repair of double-strand breaks in heterochromatin, to instead activate EBV. Notably, activation of ATM occurs in the absence of detectable DNA damage. These findings i) clarify chloroquine's effect on EBV replication, ii) should energize field investigations into the connection between chloroquine and endemic Burkitt lymphoma and iii) provide a unique context in which ATM modifies KAP1 to regulate persistence of a herpesvirus in humans.
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Affiliation(s)
- Xiaofan Li
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University School of Medicine, Stony Brook, NY, United States of America
| | - Eric M. Burton
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States of America
| | - Sumita Bhaduri-McIntosh
- Division of Infectious Diseases, Department of Pediatrics, Stony Brook University School of Medicine, Stony Brook, NY, United States of America
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY, United States of America
- * E-mail:
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Kumar B, Chandran B. KSHV Entry and Trafficking in Target Cells-Hijacking of Cell Signal Pathways, Actin and Membrane Dynamics. Viruses 2016; 8:v8110305. [PMID: 27854239 PMCID: PMC5127019 DOI: 10.3390/v8110305] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/24/2016] [Accepted: 11/03/2016] [Indexed: 01/27/2023] Open
Abstract
Kaposi's sarcoma associated herpesvirus (KSHV) is etiologically associated with human endothelial cell hyperplastic Kaposi's sarcoma and B-cell primary effusion lymphoma. KSHV infection of adherent endothelial and fibroblast cells are used as in vitro models for infection and KSHV enters these cells by host membrane bleb and actin mediated macropinocytosis or clathrin endocytosis pathways, respectively. Infection in endothelial and fibroblast cells is initiated by the interactions between multiple viral envelope glycoproteins and cell surface associated heparan sulfate (HS), integrins (α3β1, αVβ3 and αVβ5), and EphA2 receptor tyrosine kinase (EphA2R). This review summarizes the accumulated studies demonstrating that KSHV manipulates the host signal pathways to enter and traffic in the cytoplasm of the target cells, to deliver the viral genome into the nucleus, and initiate viral gene expression. KSHV interactions with the cell surface receptors is the key platform for the manipulations of host signal pathways which results in the simultaneous induction of FAK, Src, PI3-K, Rho-GTPase, ROS, Dia-2, PKC ζ, c-Cbl, CIB1, Crk, p130Cas and GEF-C3G signal and adaptor molecules that play critical roles in the modulation of membrane and actin dynamics, and in the various steps of the early stages of infection such as entry and trafficking towards the nucleus. The Endosomal Sorting Complexes Required for Transport (ESCRT) proteins are also recruited to assist in viral entry and trafficking. In addition, KSHV interactions with the cell surface receptors also induces the host transcription factors NF-κB, ERK1/2, and Nrf2 early during infection to initiate and modulate viral and host gene expression. Nuclear delivery of the viral dsDNA genome is immediately followed by the host innate responses such as the DNA damage response (DDR), inflammasome and interferon responses. Overall, these studies form the initial framework for further studies of simultaneous targeting of KSHV glycoproteins, host receptor, signal molecules and trafficking machinery that would lead into novel therapeutic methods to prevent KSHV infection of target cells and consequently the associated malignancies.
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Affiliation(s)
- Binod Kumar
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
| | - Bala Chandran
- H. M. Bligh Cancer Research Laboratories, Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL 60064, USA.
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Shao J, Huang J, Guo Y, Li L, Liu X, Chen X, Yuan J. Up-regulation of nuclear factor E2-related factor 2 (Nrf2) represses the replication of SVCV. FISH & SHELLFISH IMMUNOLOGY 2016; 58:474-482. [PMID: 27693327 DOI: 10.1016/j.fsi.2016.09.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 08/27/2016] [Accepted: 09/11/2016] [Indexed: 05/18/2023]
Abstract
Generation of reactive oxygen species (ROS) and failure to maintain an appropriate redox balance contribute to viral pathogenesis. Nuclear factor E2-related factor 2 (Nrf2) is an important transcription factor that plays a pivotal role in maintaining intracellular homoeostasis and coping with invasive pathogens by coordinately activating a series of cytoprotective genes. Previous studies indicated that the transcription and expression levels of Nrf2 were up-regulated in SVCV-infected EPC cells with the unknown mechanism(s). In this study, the interactions between the Nrf2-ARE signalling pathway and SVCV replication were investigated, which demonstrated that SVCV infection induced accumulation of ROS as well as protein carbonyl groups and 8-OHdG, accompanied by the up-regulation of Nrf2 and its downstream genes. At the same time, the activation of Nrf2 with D, l-sulforaphane (SFN) and CDDO-Me could repress the replication of SVCV, and knockdown of Nrf2 by siRNA could promote the replication of SVCV. Taken together, these observations indicate that the Nrf2-ARE signal pathway activates a passive defensive response upon SVCV infection. The conclusions presented here suggest that targeting the Nrf2 pathway has potential for combating SVCV infection.
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Affiliation(s)
- Junhui Shao
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
| | - Jiang Huang
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Yana Guo
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Lijuan Li
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
| | - Xueqin Liu
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
| | - Xiaoxuan Chen
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
| | - Junfa Yuan
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China; Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China; Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China.
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35
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Moos WH, Pinkert CA, Irwin MH, Faller DV, Kodukula K, Glavas IP, Steliou K. Epigenetic Treatment of Persistent Viral Infections. Drug Dev Res 2016; 78:24-36. [PMID: 27761936 DOI: 10.1002/ddr.21366] [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] [Indexed: 12/25/2022]
Abstract
Preclinical Research Approximately 2,500 years ago, Hippocrates used the word herpes as a medical term to describe lesions that appeared to creep or crawl on the skin, advocating heat as a possible treatment. During the last 50 years, pharmaceutical research has made great strides, and therapeutic options have expanded to include small molecule antiviral agents, protease inhibitors, preventive vaccines for a handful of the papillomaviruses, and even cures for hepatitis C virus infections. However, effective treatments for persistent and recurrent viral infections, particularly the highly prevalent herpesviruses, continue to represent a significant unmet medical need, affecting the majority of the world's population. Exploring the population diversity of the human microbiome and the effects its compositional variances have on the immune system, health, and disease are the subjects of intense investigational research and study. Among the collection of viruses, bacteria, fungi, and single-cell eukaryotes that comprise the human microbiome, the virome has been grossly understudied relative to the influence it exerts on human pathophysiology, much as mitochondria have until recently failed to receive the attention they deserve, given their critical biomedical importance. Fortunately, cellular epigenetic machinery offers a wealth of druggable targets for therapeutic intervention in numerous disease indications, including those outlined above. With advances in synthetic biology, engineering our body's commensal microorganisms to seek out and destroy pathogenic species is clearly on the horizon. This is especially the case given recent breakthroughs in genetic manipulation with tools such as the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) gene-editing platforms. Tying these concepts together with our previous work on the microbiome and neurodegenerative and neuropsychiatric diseases, we suggest that, because mammalian cells respond to a viral infection by triggering a cascade of antiviral innate immune responses governed substantially by the cell's mitochondria, small molecule carnitinoids represent a new class of therapeutics with potential widespread utility against many infectious insults. Drug Dev Res 78 : 24-36, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Walter H Moos
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, California
| | - Carl A Pinkert
- Department of Biological Sciences, College of Arts and Sciences, The University of Alabama, Tuscaloosa, Alabama
| | - Michael H Irwin
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama
| | - Douglas V Faller
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts.,Boston University School of Medicine, Cancer Research Center, Boston, Massachusetts
| | | | - Ioannis P Glavas
- Department of Ophthalmology, New York University School of Medicine, New York
| | - Kosta Steliou
- Boston University School of Medicine, Cancer Research Center, Boston, Massachusetts.,PhenoMatriX, Boston, Massachusetts
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36
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Nuclear Innate Immune DNA Sensor IFI16 Is Degraded during Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus (KSHV): Role of IFI16 in Maintenance of KSHV Latency. J Virol 2016; 90:8822-41. [PMID: 27466416 PMCID: PMC5021400 DOI: 10.1128/jvi.01003-16] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/13/2016] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED IFI16 (interferon gamma-inducible protein 16) recognizes nuclear episomal herpesvirus (Kaposi's sarcoma-associated herpesvirus [KSHV], Epstein-Barr virus [EBV], and herpes simplex virus 1 [HSV-1]) genomes and induces the inflammasome and interferon beta responses. It also acts as a lytic replication restriction factor and inhibits viral DNA replication (human cytomegalovirus [HCMV] and human papillomavirus [HPV]) and transcription (HSV-1, HCMV, and HPV) through epigenetic modifications of the viral genomes. To date, the role of IFI16 in the biology of latent viruses is not known. Here, we demonstrate that knockdown of IFI16 in the latently KSHV-infected B-lymphoma BCBL-1 and BC-3 cell lines results in lytic reactivation and increases in levels of KSHV lytic transcripts, proteins, and viral genome replication. Similar results were also observed during KSHV lytic cycle induction in TREX-BCBL-1 cells with the doxycycline-inducible lytic cycle switch replication and transcription activator (RTA) gene. Overexpression of IFI16 reduced lytic gene induction by the chemical agent 12-O-tetradecoylphorbol-13-acetate (TPA). IFI16 protein levels were significantly reduced or absent in TPA- or doxycycline-induced cells expressing lytic KSHV proteins. IFI16 is polyubiquitinated and degraded via the proteasomal pathway. The degradation of IFI16 was absent in phosphonoacetic acid-treated cells, which blocks KSHV DNA replication and, consequently, late lytic gene expression. Chromatin immunoprecipitation assays of BCBL-1 and BC-3 cells demonstrated that IFI16 binds to KSHV gene promoters. Uninfected epithelial SLK and osteosarcoma U2OS cells transfected with KSHV luciferase promoter constructs confirmed that IFI16 functions as a transcriptional repressor. These results reveal that KSHV utilizes the innate immune nuclear DNA sensor IFI16 to maintain its latency and repression of lytic transcripts, and a late lytic KSHV gene product(s) targets IFI16 for degradation during lytic reactivation. IMPORTANCE Like all herpesviruses, latency is an integral part of the life cycle of Kaposi's sarcoma-associated herpesvirus (KSHV), an etiological agent for many human cancers. Herpesviruses utilize viral and host factors to successfully evade the host immune system to maintain latency. Reactivation is a complex event where the latent episomal viral genome springs back to active transcription of lytic cycle genes. Our studies reveal that KSHV has evolved to utilize the innate immune sensor IFI16 to keep lytic cycle transcription in dormancy. We demonstrate that IFI16 binds to the lytic gene promoter, acts as a transcriptional repressor, and thereby helps to maintain latency. We also discovered that during the late stage of lytic replication, KSHV selectively degrades IFI16, thus relieving transcriptional repression. This is the first report to demonstrate the role of IFI16 in latency maintenance of a herpesvirus, and further understanding will lead to the development of strategies to eliminate latent infection.
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Abstract
Kaposi’s sarcoma (KS)-associated herpesvirus (KSHV) is an oncogenic human herpesvirus. KSHV is associated with three cancers in the human population: KS, primary effusion lymphoma (PEL), and multicentric Castleman’s disease (MCD). KS is the leading cause of cancer in HIV-infected individuals. In this review, we discuss the most recent discoveries behind the mechanisms of KSHV latency maintenance and lytic replication. We also review current therapies for KSHV-associated cancers.
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Affiliation(s)
- Nathan J Dissinger
- Lineberger Comprehensive Cancer Center and Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Blossom Damania
- Lineberger Comprehensive Cancer Center and Department of Microbiology & Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Strahan R, Uppal T, Verma SC. Next-Generation Sequencing in the Understanding of Kaposi's Sarcoma-Associated Herpesvirus (KSHV) Biology. Viruses 2016; 8:92. [PMID: 27043613 PMCID: PMC4848587 DOI: 10.3390/v8040092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 03/21/2016] [Accepted: 03/23/2016] [Indexed: 12/16/2022] Open
Abstract
Non-Sanger-based novel nucleic acid sequencing techniques, referred to as Next-Generation Sequencing (NGS), provide a rapid, reliable, high-throughput, and massively parallel sequencing methodology that has improved our understanding of human cancers and cancer-related viruses. NGS has become a quintessential research tool for more effective characterization of complex viral and host genomes through its ever-expanding repertoire, which consists of whole-genome sequencing, whole-transcriptome sequencing, and whole-epigenome sequencing. These new NGS platforms provide a comprehensive and systematic genome-wide analysis of genomic sequences and a full transcriptional profile at a single nucleotide resolution. When combined, these techniques help unlock the function of novel genes and the related pathways that contribute to the overall viral pathogenesis. Ongoing research in the field of virology endeavors to identify the role of various underlying mechanisms that control the regulation of the herpesvirus biphasic lifecycle in order to discover potential therapeutic targets and treatment strategies. In this review, we have complied the most recent findings about the application of NGS in Kaposi’s sarcoma-associated herpesvirus (KSHV) biology, including identification of novel genomic features and whole-genome KSHV diversities, global gene regulatory network profiling for intricate transcriptome analyses, and surveying of epigenetic marks (DNA methylation, modified histones, and chromatin remodelers) during de novo, latent, and productive KSHV infections.
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Affiliation(s)
- Roxanne Strahan
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Timsy Uppal
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, 1664 N, Virginia Street, MS 320, Reno, NV 89557, USA.
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STAT3 Regulates Lytic Activation of Kaposi's Sarcoma-Associated Herpesvirus. J Virol 2015; 89:11347-55. [PMID: 26339061 DOI: 10.1128/jvi.02008-15] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 08/24/2015] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Lytic activation of Kaposi's sarcoma-associated herpesvirus (KSHV) from latency is a critical contributor to pathogenesis and progression of KSHV-mediated disease. Development of targeted treatment strategies and improvement of lytic-phase-directed oncolytic therapies, therefore, hinge on gaining a better understanding of latency-to-lytic-phase transition. A key observation in that regard, also common to other herpesviruses, is the partial permissiveness of latently infected cells to lytic-cycle-inducing agents. Here, we address the molecular basis of why only some KSHV-infected cells respond to lytic stimuli. Since cellular signal transducer and activator of transcription 3 (STAT3) is constitutively active in KSHV-associated cancers, KSHV activates STAT3, and STAT3 has been found to regulate lytic activation of Epstein-Barr virus (EBV)-infected cells, we asked if STAT3 contributes similarly to the life cycle of KSHV. We found that high levels of STAT3 correlate with the refractory state at the single-cell level under conditions of both spontaneous and induced lytic activation; importantly, STAT3 also regulates lytic susceptibility. Further, knockdown of STAT3 suppresses the cellular transcriptional corepressor Krüppel-associated box domain-associated protein 1 (KAP1; also known as TRIM28), and suppression of KAP1 activates lytic genes, including the viral lytic switch RTA, thereby linking STAT3 via KAP1 to regulation of the balance between lytic and latent cells. These findings, taken together with those from EBV-infected and, more recently, herpes simplex virus 1 (HSV-1)-infected cells, cement the contribution of host STAT3 to persistence of herpesviruses and simultaneously reveal an important lead to devise strategies to improve lytic-phase-directed therapies for herpesviruses. IMPORTANCE Lytic activation of the cancer-causing Kaposi's sarcoma-associated herpesvirus (KSHV) is vital to its life cycle and causation of disease. Like other herpesviruses, however, a substantial fraction of latently infected cells are resistant to lytic-phase-inducing stimuli. Investigating the molecular basis for this refractory state is essential for understanding how the virus persists and how it causes disease and to guide efforts to improve treatment of KSHV-mediated diseases. We found that, like two other herpesviruses, EBV and HSV-1, KSHV exploits the cellular transcription factor STAT3 to regulate the susceptibility of latently infected cells to lytic triggers. These findings highlight a common STAT3-centered strategy used by herpesviruses to maintain persistence in their hosts while also revealing a key molecule to pursue while devising methods to improve herpesvirus lytic-phase-directed therapies.
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