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O'Donnell JS, Jaberolansar N, Chappell KJ. Human T-lymphotropic virus type 1 and antiretroviral therapy: practical considerations for pre-exposure and post-exposure prophylaxis, transmission prevention, and mitigation of severe disease. THE LANCET. MICROBE 2024; 5:e400-e408. [PMID: 38246188 DOI: 10.1016/s2666-5247(23)00359-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/17/2023] [Accepted: 10/24/2023] [Indexed: 01/23/2024]
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus associated with substantial risk of secondary (often life-threatening) disease for the estimated 10 million to 20 million people infected globally. Despite a clear need, no HTLV-1-specific vaccine or antiretroviral therapy has been developed to date. Instead, existing public and primary health-care interventions inadequately focus on infection prevention and management of secondary diseases. In this Personal View, we discuss the evidence that exists to support the sensitivity of HTLV-1 to antiretroviral therapies approved by the US Food and Drug Administration for the treatment of HIV-1, how this sensitivity is affected by clinically relevant virological and immunological features, and additional practical considerations for the use of antiretroviral therapies in the context of HTLV-1.
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Affiliation(s)
- Jake S O'Donnell
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia; The Australian Institute for Biotechnology and Nanotechnology, The University of Queensland, St Lucia, QLD, Australia.
| | - Noushin Jaberolansar
- The Australian Institute for Biotechnology and Nanotechnology, The University of Queensland, St Lucia, QLD, Australia
| | - Keith J Chappell
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia; The Australian Institute for Biotechnology and Nanotechnology, The University of Queensland, St Lucia, QLD, Australia; Australian Infectious Disease Research Centre, The University of Queensland, St Lucia, QLD, Australia
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2
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Tu JJ, King E, Maksimova V, Smith S, Macias R, Cheng X, Vegesna T, Yu L, Ratner L, Green PL, Niewiesk S, Richner JM, Panfil AR. An HTLV-1 envelope mRNA vaccine is immunogenic and protective in New Zealand rabbits. J Virol 2024; 98:e0162323. [PMID: 38193692 PMCID: PMC10883802 DOI: 10.1128/jvi.01623-23] [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: 10/17/2023] [Accepted: 12/07/2023] [Indexed: 01/10/2024] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus responsible for adult T-cell leukemia/lymphoma, a severe and fatal CD4+ T-cell malignancy. Additionally, HTLV-1 can lead to a chronic progressive neurodegenerative disease known as HTLV-1-associated myelopathy/tropical spastic paraparesis. Unfortunately, the prognosis for HTLV-1-related diseases is generally poor, and effective treatment options are limited. In this study, we designed and synthesized a codon optimized HTLV-1 envelope (Env) mRNA encapsulated in a lipid nanoparticle (LNP) and evaluated its efficacy as a vaccine candidate in an established rabbit model of HTLV-1 infection and persistence. Immunization regimens included a prime/boost protocol using Env mRNA-LNP or control green fluorescent protein (GFP) mRNA-LNP. After immunization, rabbits were challenged by intravenous injection with irradiated HTLV-1 producing cells. Three rabbits were partially protected and three rabbits were completely protected against HTLV-1 challenge. These rabbits were then rechallenged 15 weeks later, and two rabbits maintained sterilizing immunity. In Env mRNA-LNP immunized rabbits, proviral load and viral gene expression were significantly lower. After viral challenge in the Env mRNA-LNP vaccinated rabbits, an increase in both CD4+/IFN-γ+ and CD8+/IFN-γ+ T-cells was detected when stimulating with overlapping Env peptides. Env mRNA-LNP elicited a detectable anti-Env antibody response after prime/boost vaccination in all animals and significantly higher levels of neutralizing antibody activity. Neutralizing antibody activity was correlated with a reduction in proviral load. These findings hold promise for the development of preventive strategies and therapeutic interventions against HTLV-1 infection and its associated diseases.IMPORTANCEmRNA vaccine technology has proven to be a viable approach for effectively triggering immune responses that protect against or limit viral infections and disease. In our study, we synthesized a codon optimized human T-cell leukemia virus type 1 (HTLV-1) envelope (Env) mRNA that can be delivered in a lipid nanoparticle (LNP) vaccine approach. The HTLV-1 Env mRNA-LNP produced protective immune responses against viral challenge in a preclinical rabbit model. HTLV-1 is primarily transmitted through direct cell-to-cell contact, and the protection offered by mRNA vaccines in our rabbit model could have significant implications for optimizing the development of other viral vaccine candidates. This is particularly important in addressing the challenge of enhancing protection against infections that rely on cell-to-cell transmission.
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Affiliation(s)
- Joshua J. Tu
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Emily King
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Victoria Maksimova
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Susan Smith
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Ramon Macias
- Cellular and Molecular Biology Graduate Program, The Ohio State University, Columbus, Ohio, USA
| | - Xiaogang Cheng
- Department of Medicine, Washington University, St. Louis, Missouri, USA
| | - Tanmayee Vegesna
- Department of Microbiology and Immunology, University of Illinois-Chicago, Chicago, Illinois, USA
| | - Lianbo Yu
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, USA
| | - Lee Ratner
- Department of Medicine, Washington University, St. Louis, Missouri, USA
| | - Patrick L. Green
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
- Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Stefan Niewiesk
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
- Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
| | - Justin M. Richner
- Department of Microbiology and Immunology, University of Illinois-Chicago, Chicago, Illinois, USA
| | - Amanda R. Panfil
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, USA
- Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio, USA
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Aristodemou AEN, Rueda DS, Taylor GP, Bangham CRM. The transcriptome of HTLV-1-infected primary cells following reactivation reveals changes to host gene expression central to the proviral life cycle. PLoS Pathog 2023; 19:e1011494. [PMID: 37523412 PMCID: PMC10431621 DOI: 10.1371/journal.ppat.1011494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 08/16/2023] [Accepted: 06/19/2023] [Indexed: 08/02/2023] Open
Abstract
Infections by Human T cell Leukaemia Virus type 1 (HTLV-1) persist for the lifetime of the host by integrating into the genome of CD4+ T cells. Proviral gene expression is essential for proviral survival and the maintenance of the proviral load, through the pro-proliferative changes it induces in infected cells. Despite their role in HTLV-1 infection and a persistent cytotoxic T lymphocyte response raised against the virus, proviral transcripts from the sense-strand are rarely detected in fresh cells extracted from the peripheral blood, and have recently been found to be expressed intermittently by a small subset of cells at a given time. Ex vivo culture of infected cells prompts synchronised proviral expression in infected cells from peripheral blood, allowing the study of factors involved in reactivation in primary cells. Here, we used bulk RNA-seq to examine the host transcriptome over six days in vitro, following proviral reactivation in primary peripheral CD4+ T cells isolated from subjects with non-malignant HTLV-1 infection. Infected cells displayed a conserved response to reactivation, characterised by discrete stages of gene expression, cell division and subsequently horizontal transmission of the virus. We observed widespread changes in Polycomb gene expression following reactivation, including an increase in PRC2 transcript levels and diverse changes in the expression of PRC1 components. We hypothesize that these transcriptional changes constitute a negative feedback loop that maintains proviral latency by re-deposition of H2AK119ub1 following the end of proviral expression. Using RNAi, we found that certain deubiquitinases, BAP1, USP14 and OTUD5 each promote proviral transcription. These data demonstrate the detailed trajectory of HTLV-1 proviral reactivation in primary HTLV-1-carrier lymphocytes and the impact on the host cell.
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Affiliation(s)
- Aris E. N. Aristodemou
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - David S. Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, United Kingdom
| | - Graham P. Taylor
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Charles R. M. Bangham
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, United Kingdom
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Maksimova V, Wilkie T, Smith S, Phelps C, Melvin C, Yu L, Niewiesk S, Green PL, Panfil AR. HTLV-1 Hbz protein, but not hbz mRNA secondary structure, is critical for viral persistence and disease development. PLoS Pathog 2023; 19:e1011459. [PMID: 37327244 DOI: 10.1371/journal.ppat.1011459] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 06/05/2023] [Indexed: 06/18/2023] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic cause of adult T-cell leukemia/lymphoma (ATL) and encodes a viral oncoprotein (Hbz) that is consistently expressed in asymptomatic carriers and ATL patients, suggesting its importance in the development and maintenance of HTLV-1 leukemic cells. Our previous work found Hbz protein is dispensable for virus-mediated T-cell immortalization but enhances viral persistence. We and others have also shown that hbz mRNA promotes T-cell proliferation. In our current studies, we evaluated the role of hbz mRNA on HTLV-1-mediated immortalization in vitro as well as in vivo persistence and disease development. We generated mutant proviral clones to examine the individual contributions of hbz mRNA, hbz mRNA secondary structure (stem-loop), and Hbz protein. Wild-type (WT) and all mutant viruses produced virions and immortalized T-cells in vitro. Viral persistence and disease development were also evaluated in vivo by infection of a rabbit model and humanized immune system (HIS) mice, respectively. Proviral load and sense and antisense viral gene expression were significantly lower in rabbits infected with mutant viruses lacking Hbz protein compared to WT or virus with an altered hbz mRNA stem-loop (M3 mutant). HIS mice infected with Hbz protein-deficient viruses showed significantly increased survival times compared to animals infected with WT or M3 mutant virus. Altered hbz mRNA secondary structure, or loss of hbz mRNA or protein, has no significant effect on T-cell immortalization induced by HTLV-1 in vitro; however, the Hbz protein plays a critical role in establishing viral persistence and leukemogenesis in vivo.
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Affiliation(s)
- Victoria Maksimova
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Tasha Wilkie
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Susan Smith
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Cameron Phelps
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Corrine Melvin
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Lianbo Yu
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Stefan Niewiesk
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Patrick L Green
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
- Comprehensive Cancer Center and Solove Research Institute, The Ohio State University, Columbus, Ohio, United States
| | - Amanda R Panfil
- Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
- Comprehensive Cancer Center and Solove Research Institute, The Ohio State University, Columbus, Ohio, United States
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Bangham CRM. HTLV-1 persistence and the oncogenesis of adult T-cell leukemia/lymphoma. Blood 2023; 141:2299-2306. [PMID: 36800643 PMCID: PMC10646791 DOI: 10.1182/blood.2022019332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/19/2023] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1), also known as human T-lymphotropic virus type 1, causes the aggressive malignancy known as adult T-cell leukemia/lymphoma (ATL) in 5% of infected people and a chronic progressive inflammatory disease of the central nervous system, HTLV-1-associated myelopathy, in ∼0.3% to 4% of them, varying between regions where it is endemic. Reliable treatments are lacking for both conditions, although there have been promising recent advances in the prevention and treatment of ATL. Because ATL typically develops after several decades of infection, it is necessary to understand how the virus persists in the host despite a strong immune response, and how this persistence results in oncogenesis.
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Hleihel R, Skayneh H, de Thé H, Hermine O, Bazarbachi A. Primary cells from patients with adult T cell leukemia/lymphoma depend on HTLV-1 Tax expression for NF-κB activation and survival. Blood Cancer J 2023; 13:67. [PMID: 37137914 PMCID: PMC10156663 DOI: 10.1038/s41408-023-00841-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/13/2023] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
Adult T cell leukemia/lymphoma (ATL) is an aggressive malignancy secondary to chronic infection with human T cell leukemia virus type 1 (HTLV-1). The viral oncoprotein Tax initiates T cell transformation through activation of critical cellular pathways, including NF-κB. Unexpectedly, Tax protein is not detectable in most ATL cells, in contrast to the HTLV-1 HBZ protein which antagonizes Tax effects. Here, we demonstrate that primary ATL cells from patients with acute or chronic ATL express very low levels of Tax mRNA and protein. Critically, survival of these primary ATL cells is dependent on continued Tax expression. Mechanistically, Tax extinction results in reversal of NF-κB activation, P53/PML activation and apoptosis. Tax drives interleukin-10 (IL-10) expression and recombinant IL-10 rescues the survival of tax-depleted primary ATL cells. These results demonstrate the critical role of continued Tax and IL-10 expression for the survival of primary ATL cells, highlighting their relevance as therapeutic targets.
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Affiliation(s)
- Rita Hleihel
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Hala Skayneh
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Hugues de Thé
- INSERM UMR 944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Université Paris-Cité, Hôpital St. Louis 1, Paris, France
- Service d'Hématologie, Assistance Publique, Hôpital St. Louis 1, Paris, France
- College de France, PSL research University, Paris, France
| | - Olivier Hermine
- Institut Imagine-INSERM U1163, Necker Hospital, University of Paris, Paris, France
- Department of Hematology, Necker Hospital, University of Paris, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Ali Bazarbachi
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
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Ramanayake S, Moulding DA, Tanaka Y, Singh A, Bangham CRM. Dynamics and consequences of the HTLV-1 proviral plus-strand burst. PLoS Pathog 2022; 18:e1010774. [PMID: 36441826 PMCID: PMC9731428 DOI: 10.1371/journal.ppat.1010774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 12/08/2022] [Accepted: 11/15/2022] [Indexed: 11/30/2022] Open
Abstract
Expression of the transcriptional transactivator protein Tax, encoded on the proviral plus-strand of human T-cell leukaemia virus type 1 (HTLV-1), is crucial for the replication of the virus, but Tax-expressing cells are rarely detected in fresh blood ex vivo. The dynamics and consequences of the proviral plus-strand transcriptional burst remain insufficiently characterised. We combined time-lapse live-cell imaging, single-cell tracking and mathematical modelling to study the dynamics of Tax expression at single-cell resolution in two naturally-infected, non-malignant T-cell clones transduced with a short-lived enhanced green fluorescent protein (d2EGFP) Tax reporter system. Five different patterns of Tax expression were observed during the 30-hour observation period; the distribution of these patterns differed between the two clones. The mean duration of Tax expression in the two clones was 94 and 417 hours respectively, estimated from mathematical modelling of the experimental data. Tax expression was associated with a transient slowing in cell-cycle progression and proliferation, increased apoptosis, and enhanced activation of the DNA damage response pathways. Longer-term follow-up (14 days) revealed an increase in the proportion of proliferating cells and a decrease in the fraction of apoptotic cells as the cells ceased Tax expression, resulting in a greater net expansion of the initially Tax-positive population. Time-lapse live-cell imaging showed enhanced cell-to-cell adhesion among Tax-expressing cells, and decreased cell motility of Tax-expressing cells at the single-cell level. The results demonstrate the within-clone and between-clone heterogeneity in the dynamics and patterns of HTLV-1 plus-strand transcriptional bursts and the balance of positive and negative consequences of the burst for the host cell.
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Affiliation(s)
- Saumya Ramanayake
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Dale A. Moulding
- Light Microscopy Core Facility, Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Yuetsu Tanaka
- Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Abhyudai Singh
- Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware, United States of America
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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Schnell AP, Kohrt S, Aristodemou A, Taylor GP, Bangham CRM, Thoma-Kress AK. HDAC inhibitors Panobinostat and Romidepsin enhance tax transcription in HTLV-1-infected cell lines and freshly isolated patients’ T-cells. Front Immunol 2022; 13:978800. [PMID: 36052071 PMCID: PMC9424546 DOI: 10.3389/fimmu.2022.978800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
The viral transactivator Tax plays a key role in HTLV-1 reactivation and de novo infection. Previous approaches focused on the histone deacetylase inhibitor (HDACi) Valproate as a latency-reversing agent to boost Tax expression and expose infected cells to the host’s immune response. However, following treatment with Valproate proviral load decreases in patients with HAM/TSP were only transient. Here, we hypothesize that other compounds, including more potent and selective HDACi, might prove superior to Valproate in manipulating Tax expression. Thus, a panel of HDACi (Vorinostat/SAHA/Zolinza, Panobinostat/LBH589/Farydak, Belinostat/PXD101/Beleodaq, Valproate, Entinostat/MS-275, Romidepsin/FK228/Istodax, and MC1568) was selected and tested for toxicity and potency in enhancing Tax expression. The impact of the compounds was evaluated in different model systems, including transiently transfected T-cells, chronically HTLV-1-infected T-cell lines, and freshly isolated PBMCs from HTLV-1 carriers ex vivo. We identified the pan-HDACi Panobinostat and class I HDACi Romidepsin as particularly potent agents at raising Tax expression. qRT-PCR analysis revealed that these inhibitors considerably boost tax and Tax-target gene transcription. However, despite this significant increase in tax transcription and histone acetylation, protein levels of Tax were only moderately enhanced. In conclusion, these data demonstrate the ability of Panobinostat and Romidepsin to manipulate Tax expression and provide a foundation for further research into eliminating latently infected cells. These findings also contribute to a better understanding of conditions limiting transcription and translation of viral gene products.
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Affiliation(s)
- Annika P. Schnell
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Stephan Kohrt
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Aris Aristodemou
- Section of Immunology of Infection, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Graham P. Taylor
- Section of Virology, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Charles R. M. Bangham
- Section of Immunology of Infection, Department of Infectious Disease, Imperial College London, London, United Kingdom
| | - Andrea K. Thoma-Kress
- Institute of Clinical and Molecular Virology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- *Correspondence: Andrea K. Thoma-Kress,
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Carcone A, Journo C, Dutartre H. Is the HTLV-1 Retrovirus Targeted by Host Restriction Factors? Viruses 2022; 14:v14081611. [PMID: 35893677 PMCID: PMC9332716 DOI: 10.3390/v14081611] [Citation(s) in RCA: 2] [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: 06/01/2022] [Revised: 07/18/2022] [Accepted: 07/19/2022] [Indexed: 02/04/2023] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1), the etiological agent of adult T cell leukemia/lymphoma (ATLL) and of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), was identified a few years before Human Immunodeficiency Virus (HIV). However, forty years later, our comprehension of HTLV-1 immune detection and the host immune responses to HTLV-1 is far more limited than for HIV. In addition to innate and adaptive immune responses that rely on specialized cells of the immune system, host cells may also express a range of antiviral factors that inhibit viral replication at different stages of the cycle, in a cell-autonomous manner. Multiple antiviral factors allowing such an intrinsic immunity have been primarily and extensively described in the context HIV infection. Here, we provide an overview of whether known HIV restriction factors might act on HTLV-1 replication. Interestingly, many of them do not exert any antiviral activity against HTLV-1, and we discuss viral replication cycle specificities that could account for these differences. Finally, we highlight future research directions that could help to identify antiviral factors specific to HTLV-1.
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Kiik H, Ramanayake S, Miura M, Tanaka Y, Melamed A, Bangham CRM. Time-course of host cell transcription during the HTLV-1 transcriptional burst. PLoS Pathog 2022; 18:e1010387. [PMID: 35576236 PMCID: PMC9135347 DOI: 10.1371/journal.ppat.1010387] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/26/2022] [Accepted: 04/22/2022] [Indexed: 12/30/2022] Open
Abstract
The human T-cell leukemia virus type 1 (HTLV-1) transactivator protein Tax has pleiotropic functions in the host cell affecting cell-cycle regulation, DNA damage response pathways and apoptosis. These actions of Tax have been implicated in the persistence and pathogenesis of HTLV-1-infected cells. It is now known that tax expression occurs in transcriptional bursts of the proviral plus-strand, but the effects of the burst on host transcription are not fully understood. We carried out RNA sequencing of two naturally-infected T-cell clones transduced with a Tax-responsive Timer protein, which undergoes a time-dependent shift in fluorescence emission, to study transcriptional changes during successive phases of the HTLV-1 plus-strand burst. We found that the transcriptional regulation of genes involved in the NF-κB pathway, cell-cycle regulation, DNA damage response and apoptosis inhibition were immediate effects accompanying the plus-strand burst, and are limited to the duration of the burst. The results distinguish between the immediate and delayed effects of HTLV-1 reactivation on host transcription, and between clone-specific effects and those observed in both clones. The major transcriptional changes in the infected host T-cells observed here, including NF-κB, are transient, suggesting that these pathways are not persistently activated at high levels in HTLV-1-infected cells. The two clones diverged strongly in their expression of genes regulating the cell cycle. Up-regulation of senescence markers was a delayed effect of the proviral plus-strand burst and the up-regulation of some pro-apoptotic genes outlasted the burst. We found that activation of the aryl hydrocarbon receptor (AhR) pathway enhanced and prolonged the proviral burst, but did not increase the rate of reactivation. Our results also suggest that sustained plus-strand expression is detrimental to the survival of infected cells.
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Affiliation(s)
- Helen Kiik
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Saumya Ramanayake
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Michi Miura
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Yuetsu Tanaka
- Department of Infectious Disease and Immunology, Okinawa-Asia Research Center of Medical Science, Faculty of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Anat Melamed
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Charles R. M. Bangham
- Department of Infectious Diseases, Faculty of Medicine, Imperial College London, London, United Kingdom
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NF-κB-Induced R-Loops and Genomic Instability in HTLV-1-Infected and Adult T-Cell Leukemia Cells. Viruses 2022; 14:v14050877. [PMID: 35632619 PMCID: PMC9147355 DOI: 10.3390/v14050877] [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: 03/24/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 02/04/2023] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a human delta retrovirus that causes adult T-cell leukemia/lymphoma (ATL) in 3–5% of the infected population after decades of clinical latency. HTLV-1 Tax is a potent activator of IKK/NF-κB and a clastogen. While NF-κB activities are associated with cell survival and proliferation, constitutive NF-κB activation (NF-κB hyperactivation) by Tax leads to senescence and oncogenesis. Until recently, the mechanisms underlying the DNA damage and senescence induced by Tax and NF-κB were unknown. Current data indicate that NF-κB hyperactivation by Tax causes the accumulation of a nucleic acid structure known as an R-loop. R-loop excision by the transcription-coupled nucleotide excision repair (TC-NER) endonucleases, Xeroderma pigmentosum F (XPF), and XPG, in turn, promotes DNA double-strand breaks (DSBs). NF-κB blockade prevents Tax-induced R-loop accumulation, DNA damage, and senescence. In the same vein, the silencing of XPF and XPG mitigates Tax senescence, while deficiency in either or both frequently occurs in ATL of all types. ATL cells maintain constitutively active NF-κB, accumulate R-loops, and resist Tax-induced senescence. These results suggest that ATL cells must have acquired adaptive changes to prevent senescence and benefit from the survival and proliferation advantages conferred by Tax and NF-κB. In this review, the roles of R-loops in Tax- and NF-κB-induced DNA DSBs, senescence, and ATL development, and the epigenetic and genetic alterations that arise in ATL to reduce R-loop-associated DNA damage and avert senescence will be discussed.
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12
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Clinical and Public Health Implications of Human T-Lymphotropic Virus Type 1 Infection. Clin Microbiol Rev 2022; 35:e0007821. [PMID: 35195446 PMCID: PMC8941934 DOI: 10.1128/cmr.00078-21] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Human T-lymphotropic virus type 1 (HTLV-1) is estimated to affect 5 to 10 million people globally and can cause severe and potentially fatal disease, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The burden of HTLV-1 infection appears to be geographically concentrated, with high prevalence in discrete regions and populations. While most high-income countries have introduced HTLV-1 screening of blood donations, few other public health measures have been implemented to prevent infection or its consequences. Recent advocacy from concerned researchers, clinicians, and community members has emphasized the potential for improved prevention and management of HTLV-1 infection. Despite all that has been learned in the 4 decades following the discovery of HTLV-1, gaps in knowledge across clinical and public health aspects persist, impeding optimal control and prevention, as well as the development of policies and guidelines. Awareness of HTLV-1 among health care providers, communities, and affected individuals remains limited, even in countries of endemicity. This review provides a comprehensive overview on HTLV-1 epidemiology and on clinical and public health and highlights key areas for further research and collaboration to advance the health of people with and at risk of HTLV-1 infection.
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13
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Miura M, Naito T, Saito M. Current Perspectives in Human T-Cell Leukemia Virus Type 1 Infection and Its Associated Diseases. Front Med (Lausanne) 2022; 9:867478. [PMID: 35463007 PMCID: PMC9024061 DOI: 10.3389/fmed.2022.867478] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/15/2022] [Indexed: 11/25/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a replication-competent human retrovirus associated with two distinct types of diseases: a malignancy of mature CD4+ T cells called adult T-cell leukemia-lymphoma (ATL) and a chronic inflammatory central nervous system disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It was the first human retrovirus ever associated with a human cancer. Although most HTLV-1-infected individuals remain asymptomatic for life, a subpopulation develops ATL or HAM/TSP. Although the factors that cause these different manifestations of HTLV-1 infection are not fully understood, accumulating evidence suggests that the complex virus-host interactions, as well as the host immune response against HTLV-1 infection, appear to regulate the development of HTLV-1-associated diseases. This review outlines and discusses the current understanding, ongoing developments, and future perspectives of HTLV-1 research.
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14
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Gallo RC, Tagaya Y. Reflections on Some of the Exceptional Features of HTLV-1 and HTLV-1 Research: A Perspective. Front Immunol 2022; 13:859654. [PMID: 35432297 PMCID: PMC9010860 DOI: 10.3389/fimmu.2022.859654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 02/28/2022] [Indexed: 11/22/2022] Open
Abstract
The report is not a review or a summary. In a manner, it is a perspective but an unusual one. It looks back to the years my colleagues and I (RG) began preparing for human retroviruses (beginning in 1970), how they evolved, and attempts to bring to light or simply to emphasize many exceptional characteristics of a retrovirus known as HTLV-1 and some fortuitous coincidences, with emphasis on the needs of the field. These events cover over one half a century. We have had many reviews on HTLV-1 disease, epidemiology, and basic aspects of its replication, genome, gene functions, structure, and pathogenesis, though continued updates are needed. However, some of its truly exceptional features have not been highlighted, or at least not in a comprehensive manner. This article attempts to do so.
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Affiliation(s)
- Robert C. Gallo
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Robert C. Gallo,
| | - Yutaka Tagaya
- Cell Biology Lab, Division of Virology, Pathogenesis and Cancer, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD, United States
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15
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Maksimova V, Panfil AR. Human T-Cell Leukemia Virus Type 1 Envelope Protein: Post-Entry Roles in Viral Pathogenesis. Viruses 2022; 14:v14010138. [PMID: 35062342 PMCID: PMC8778545 DOI: 10.3390/v14010138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 11/16/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that is the causative infectious agent of adult T-cell leukemia/lymphoma (ATL), an aggressive and fatal CD4+ T-cell malignancy, and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a chronic neurological disease. Disease progression in infected individuals is the result of HTLV-1-driven clonal expansion of CD4+ T-cells and is generally associated with the activities of the viral oncoproteins Tax and Hbz. A closely related virus, HTLV-2, exhibits similar genomic features and the capacity to transform T-cells, but is non-pathogenic. In vitro, HTLV-1 primarily immortalizes or transforms CD4+ T-cells, while HTLV-2 displays a transformation tropism for CD8+ T-cells. This distinct tropism is recapitulated in infected people. Through comparative studies, the genetic determinant for this divergent tropism of HTLV-1/2 has been mapped to the viral envelope (Env). In this review, we explore the emerging roles for Env beyond initial viral entry and examine current perspectives on its contributions to HTLV-1-mediated disease development.
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Affiliation(s)
- Victoria Maksimova
- Biomedical Sciences Graduate Program, Center for Retrovirus Research, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA;
| | - Amanda R. Panfil
- Center for Retrovirus Research, Comprehensive Cancer Center and Solove Research Institute, Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
- Correspondence:
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16
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Maksimova V, Smith S, Seth J, Phelps C, Niewiesk S, Satou Y, Green P, Panfil AR. HTLV-1 intragenic viral enhancer influences immortalization phenotype in vitro, but is dispensable for persistence and disease development in animal models. Front Immunol 2022; 13:954077. [PMID: 35958554 PMCID: PMC9359075 DOI: 10.3389/fimmu.2022.954077] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is the causative infectious agent of adult T-cell leukemia/lymphoma (ATL) and chronic neurological disease. The disparity between silenced sense transcription versus constitutively active antisense (Hbz) transcription from the integrated provirus is not fully understood. The presence of an internal viral enhancer has recently been discovered in the Tax gene near the 3' long terminal repeat (LTR) of HTLV-1. In vitro, this enhancer has been shown to bind SRF and ELK-1 host transcription factors, maintain chromatin openness and viral gene transcription, and induce aberrant host gene transcription near viral integration sites. However, the function of the viral enhancer in the context of early HTLV-1 infection events remains unknown. In this study, we generated a mutant Enhancer virus (mEnhancer) and evaluated its effects on HTLV-1-mediated in vitro immortalization, establishment of persistent infection with an in vivo rabbit model, and disease development in a humanized immune system (HIS) mouse model. The mEnhancer virus was able to establish persistent infection in rabbits, and there were no significant differences in proviral load or HTLV-1-specific antibody responses over a 25-week study. However, rabbits infected with the mEnhancer virus had significantly decreased sense and antisense viral gene expression at 12-weeks post-infection. HIS mice infected with wt or mEnhancer virus showed similar disease progression, proviral load, and viral gene expression. While mEnhancer virus was able to sufficiently immortalize primary T-lymphocytes in cell culture, the immortalized cells had an altered phenotype (CD8+ T-cells), decreased proviral load, decreased sense and anti-sense gene expression, and altered cell cycle progression compared to HTLV-1.wt immortalized cells (CD4+ T-cells). These results suggest that the HTLV-1 enhancer element alone does not determine persistence or disease development but plays a pivotal role in regulating viral gene expression.
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Affiliation(s)
- Victoria Maksimova
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Susan Smith
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Jaideep Seth
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Cameron Phelps
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Stefan Niewiesk
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Yorifumi Satou
- Division of Genomics and Transcriptomics, Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Patrick L. Green
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
- Comprehensive Cancer Center and Solove Research Institute, The Ohio State University, Columbus, OH, United States
| | - Amanda R. Panfil
- Department of Veterinary Biosciences, Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
- Comprehensive Cancer Center and Solove Research Institute, The Ohio State University, Columbus, OH, United States
- *Correspondence: Amanda R. Panfil,
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17
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Hiyoshi M, Takahashi N, Eltalkhawy YM, Noyori O, Lotfi S, Panaampon J, Okada S, Tanaka Y, Ueno T, Fujisawa JI, Sato Y, Suzuki T, Hasegawa H, Tokunaga M, Satou Y, Yasunaga JI, Matsuoka M, Utsunomiya A, Suzu S. M-Sec induced by HTLV-1 mediates an efficient viral transmission. PLoS Pathog 2021; 17:e1010126. [PMID: 34843591 PMCID: PMC8659635 DOI: 10.1371/journal.ppat.1010126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/09/2021] [Accepted: 11/17/2021] [Indexed: 11/19/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) infects target cells primarily through cell-to-cell routes. Here, we provide evidence that cellular protein M-Sec plays a critical role in this process. When purified and briefly cultured, CD4+ T cells of HTLV-1 carriers, but not of HTLV-1- individuals, expressed M-Sec. The viral protein Tax was revealed to mediate M-Sec induction. Knockdown or pharmacological inhibition of M-Sec reduced viral infection in multiple co-culture conditions. Furthermore, M-Sec knockdown reduced the number of proviral copies in the tissues of a mouse model of HTLV-1 infection. Phenotypically, M-Sec knockdown or inhibition reduced not only plasma membrane protrusions and migratory activity of cells, but also large clusters of Gag, a viral structural protein required for the formation of viral particles. Taken together, these results suggest that M-Sec induced by Tax mediates an efficient cell-to-cell viral infection, which is likely due to enhanced membrane protrusions, cell migration, and the clustering of Gag. In the present study, we identified the cellular protein M-Sec as a host factor necessary for de novo infection of human T-cell leukemia virus type 1 (HTLV-1), the causative retrovirus of an aggressive blood cancer known as adult T-cell leukemia/lymphoma. The inhibition or knockdown of M-Sec in infected cells resulted in a reduced viral infection in several culture models and a mouse model. We recently demonstrated a similar role of M-Sec in macrophages infected with another human retrovirus HIV-1, but it has been generally thought that M-Sec is not related to HTLV-1 infection because of the lack of its expression in CD4+ T cells, the major target of HTLV-1. In this study, we revealed that CD4+ T cells of HTLV-1 asymptomatic carriers, but not those of HTLV-1- individuals, expressed M-Sec, and that the viral protein Tax mediated the induction of M-Sec. Thus, M-Sec is a new and useful tool for further understanding the process of HTLV-1 transmission.
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Affiliation(s)
- Masateru Hiyoshi
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Tokyo, Japan
- * E-mail: (MH); (SS)
| | - Naofumi Takahashi
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Youssef M. Eltalkhawy
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Osamu Noyori
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Sameh Lotfi
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Jutatip Panaampon
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Seiji Okada
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Yuetsu Tanaka
- School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Takaharu Ueno
- Department of Microbiology, Kansai Medical University, Osaka, Japan
| | | | - Yuko Sato
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Tadaki Suzuki
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hideki Hasegawa
- Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan
| | - Masahito Tokunaga
- Department of Hematology, Imamura General Hospital, Kagoshima, Japan
| | - Yorifumi Satou
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
| | - Jun-ichirou Yasunaga
- Department of Hematology, Rheumatology and Infectious Diseases, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Masao Matsuoka
- Department of Hematology, Rheumatology and Infectious Diseases, Kumamoto University School of Medicine, Kumamoto, Japan
| | - Atae Utsunomiya
- Department of Hematology, Imamura General Hospital, Kagoshima, Japan
- Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Shinya Suzu
- Joint Research Center for Human Retrovirus Infection, Kumamoto University, Kumamoto, Japan
- * E-mail: (MH); (SS)
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18
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Vandermeulen C, O’Grady T, Wayet J, Galvan B, Maseko S, Cherkaoui M, Desbuleux A, Coppin G, Olivet J, Ben Ameur L, Kataoka K, Ogawa S, Hermine O, Marcais A, Thiry M, Mortreux F, Calderwood MA, Van Weyenbergh J, Peloponese JM, Charloteaux B, Van den Broeke A, Hill DE, Vidal M, Dequiedt F, Twizere JC. The HTLV-1 viral oncoproteins Tax and HBZ reprogram the cellular mRNA splicing landscape. PLoS Pathog 2021; 17:e1009919. [PMID: 34543356 PMCID: PMC8483338 DOI: 10.1371/journal.ppat.1009919] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/30/2021] [Accepted: 08/27/2021] [Indexed: 12/12/2022] Open
Abstract
Viral infections are known to hijack the transcription and translation of the host cell. However, the extent to which viral proteins coordinate these perturbations remains unclear. Here we used a model system, the human T-cell leukemia virus type 1 (HTLV-1), and systematically analyzed the transcriptome and interactome of key effectors oncoviral proteins Tax and HBZ. We showed that Tax and HBZ target distinct but also common transcription factors. Unexpectedly, we also uncovered a large set of interactions with RNA-binding proteins, including the U2 auxiliary factor large subunit (U2AF2), a key cellular regulator of pre-mRNA splicing. We discovered that Tax and HBZ perturb the splicing landscape by altering cassette exons in opposing manners, with Tax inducing exon inclusion while HBZ induces exon exclusion. Among Tax- and HBZ-dependent splicing changes, we identify events that are also altered in Adult T cell leukemia/lymphoma (ATLL) samples from two independent patient cohorts, and in well-known cancer census genes. Our interactome mapping approach, applicable to other viral oncogenes, has identified spliceosome perturbation as a novel mechanism coordinated by Tax and HBZ to reprogram the transcriptome. Tax and HBZ are two viral regulatory proteins encoded by the human T-cell leukemia virus type 1 (HTLV-1) via sense and antisense transcripts, respectively. Both proteins are known to drive oncogenic processes that culminate in a T-cell neoplasm, known as Adult T cell leukemia/lymphoma (ATLL). We measured the effects of Tax and HBZ on host gene expression pathway by analyzing the interactome with cellular transcriptional and post-transcriptional regulators, and the transcriptome and mRNA splicing of cell lines expressing either Tax or HBZ. We compared our results with data obtained from independent cohorts of Japanese and Afro-Caribbean patients, and identified common splicing changes that might represent clinically useful biomarkers for ATLL. Finally, we provide evidence that the viral protein Tax can reprogram initial steps of the T-cell transcriptome diversification by hijacking the U2AF complex, a key cellular regulator of pre-mRNA splicing.
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Affiliation(s)
- Charlotte Vandermeulen
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Laboratory of Gene Expression and Cancer, GIGA Institute, University of Liege, Liege, Belgium
| | - Tina O’Grady
- Laboratory of Gene Expression and Cancer, GIGA Institute, University of Liege, Liege, Belgium
| | - Jerome Wayet
- Unit of Animal Genomics, GIGA, Université de Liège (ULiège), Liège, Belgium
| | - Bartimee Galvan
- Laboratory of Gene Expression and Cancer, GIGA Institute, University of Liege, Liege, Belgium
| | - Sibusiso Maseko
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
| | - Majid Cherkaoui
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
| | - Alice Desbuleux
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Georges Coppin
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Julien Olivet
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Lamya Ben Ameur
- Laboratory of Biology and Modeling of the Cell, CNRS UMR 5239, INSERM U1210, University of Lyon, Lyon, France
| | - Keisuke Kataoka
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Olivier Hermine
- Service Hématologie Adultes, Assistance Publique-Hôpitaux de Paris, Hôpital Necker Enfants Malades, Université de Paris, Laboratoire d’onco-hématologie, Institut Necker-Enfants Malades, INSERM U1151, Université de Paris, Paris, France
| | - Ambroise Marcais
- Service Hématologie Adultes, Assistance Publique-Hôpitaux de Paris, Hôpital Necker Enfants Malades, Université de Paris, Laboratoire d’onco-hématologie, Institut Necker-Enfants Malades, INSERM U1151, Université de Paris, Paris, France
| | - Marc Thiry
- Unit of Cell and Tissue Biology, GIGA Institute, University of Liege, Liege, Belgium
| | - Franck Mortreux
- Laboratory of Biology and Modeling of the Cell, CNRS UMR 5239, INSERM U1210, University of Lyon, Lyon, France
| | - Michael A. Calderwood
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
| | - Johan Van Weyenbergh
- Laboratory of Clinical and Epidemiological Virology, Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Catholic University of Leuven, Leuven, Belgium
| | | | - Benoit Charloteaux
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Human Genetics, CHU of Liege, University of Liege, Liege, Belgium
| | - Anne Van den Broeke
- Unit of Animal Genomics, GIGA, Université de Liège (ULiège), Liège, Belgium
- Laboratory of Experimental Hematology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Brussels, Belgium
- * E-mail: (AVdB); (DEH); (MV); (FD); (J-CT)
| | - David E. Hill
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- * E-mail: (AVdB); (DEH); (MV); (FD); (J-CT)
| | - Marc Vidal
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (AVdB); (DEH); (MV); (FD); (J-CT)
| | - Franck Dequiedt
- Laboratory of Gene Expression and Cancer, GIGA Institute, University of Liege, Liege, Belgium
- * E-mail: (AVdB); (DEH); (MV); (FD); (J-CT)
| | - Jean-Claude Twizere
- Laboratory of Viral Interactomes, GIGA Institute, University of Liege, Liege, Belgium
- Center for Cancer Systems Biology (CCSB), Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- * E-mail: (AVdB); (DEH); (MV); (FD); (J-CT)
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19
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Schnell AP, Kohrt S, Thoma-Kress AK. Latency Reversing Agents: Kick and Kill of HTLV-1? Int J Mol Sci 2021; 22:ijms22115545. [PMID: 34073995 PMCID: PMC8197370 DOI: 10.3390/ijms22115545] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 05/19/2021] [Accepted: 05/20/2021] [Indexed: 12/14/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1), the cause of adult T-cell leukemia/lymphoma (ATLL), is a retrovirus, which integrates into the host genome and persistently infects CD4+ T-cells. Virus propagation is stimulated by (1) clonal expansion of infected cells and (2) de novo infection. Viral gene expression is induced by the transactivator protein Tax, which recruits host factors like positive transcription elongation factor b (P-TEFb) to the viral promoter. Since HTLV-1 gene expression is repressed in vivo by viral, cellular, and epigenetic mechanisms in late phases of infection, HTLV-1 avoids an efficient CD8+ cytotoxic T-cell (CTL) response directed against the immunodominant viral Tax antigen. Hence, therapeutic strategies using latency reversing agents (LRAs) sought to transiently activate viral gene expression and antigen presentation of Tax to enhance CTL responses towards HTLV-1, and thus, to expose the latent HTLV-1 reservoir to immune destruction. Here, we review strategies that aimed at enhancing Tax expression and Tax-specific CTL responses to interfere with HTLV-1 latency. Further, we provide an overview of LRAs including (1) histone deacetylase inhibitors (HDACi) and (2) activators of P-TEFb, that have mainly been studied in context of human immunodeficiency virus (HIV), but which may also be powerful in the context of HTLV-1.
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20
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Liu J, Hansen D, Eck E, Kim YJ, Turner M, Alamos S, Garcia HG. Real-time single-cell characterization of the eukaryotic transcription cycle reveals correlations between RNA initiation, elongation, and cleavage. PLoS Comput Biol 2021; 17:e1008999. [PMID: 34003867 PMCID: PMC8162642 DOI: 10.1371/journal.pcbi.1008999] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 05/28/2021] [Accepted: 04/23/2021] [Indexed: 12/23/2022] Open
Abstract
The eukaryotic transcription cycle consists of three main steps: initiation, elongation, and cleavage of the nascent RNA transcript. Although each of these steps can be regulated as well as coupled with each other, their in vivo dissection has remained challenging because available experimental readouts lack sufficient spatiotemporal resolution to separate the contributions from each of these steps. Here, we describe a novel application of Bayesian inference techniques to simultaneously infer the effective parameters of the transcription cycle in real time and at the single-cell level using a two-color MS2/PP7 reporter gene and the developing fruit fly embryo as a case study. Our method enables detailed investigations into cell-to-cell variability in transcription-cycle parameters as well as single-cell correlations between these parameters. These measurements, combined with theoretical modeling, suggest a substantial variability in the elongation rate of individual RNA polymerase molecules. We further illustrate the power of this technique by uncovering a novel mechanistic connection between RNA polymerase density and nascent RNA cleavage efficiency. Thus, our approach makes it possible to shed light on the regulatory mechanisms in play during each step of the transcription cycle in individual, living cells at high spatiotemporal resolution.
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Affiliation(s)
- Jonathan Liu
- Department of Physics, University of California at Berkeley, Berkeley, California, United States of America
| | - Donald Hansen
- Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, Heidelberg, Germany
| | - Elizabeth Eck
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California, United States of America
| | - Yang Joon Kim
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California, United States of America
| | - Meghan Turner
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California, United States of America
| | - Simon Alamos
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, California, United States of America
| | - Hernan G. Garcia
- Department of Physics, University of California at Berkeley, Berkeley, California, United States of America
- Biophysics Graduate Group, University of California at Berkeley, Berkeley, California, United States of America
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, California, United States of America
- Institute for Quantitative Biosciences-QB3, University of California at Berkeley, Berkeley, California, United States of America
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21
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Izaki M, Yasunaga JI, Nosaka K, Sugata K, Utsunomiya H, Suehiro Y, Shichijo T, Yamada A, Sugawara Y, Hibi T, Inomata Y, Akari H, Melamed A, Bangham C, Matsuoka M. In vivo dynamics and adaptation of HTLV-1-infected clones under different clinical conditions. PLoS Pathog 2021; 17:e1009271. [PMID: 33524072 PMCID: PMC7877780 DOI: 10.1371/journal.ppat.1009271] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 02/11/2021] [Accepted: 01/04/2021] [Indexed: 12/18/2022] Open
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) spreads through cell contact. Therefore, this virus persists and propagates within the host by two routes: clonal proliferation of infected cells and de novo infection. The proliferation is influenced by the host immune responses and expression of viral genes. However, the detailed mechanisms that control clonal expansion of infected cells remain to be elucidated. In this study, we show that newly infected clones were strongly suppressed, and then stable clones were selected, in a patient who was infected by live liver transplantation from a seropositive donor. Conversely, most HTLV-1+ clones persisted in patients who received hematopoietic stem cell transplantation from seropositive donors. To clarify the role of cell-mediated immunity in this clonal selection, we suppressed CD8+ or CD16+ cells in simian T-cell leukemia virus type 1 (STLV-1)-infected Japanese macaques. Decreasing CD8+ T cells had marginal effects on proviral load (PVL). However, the clonality of infected cells changed after depletion of CD8+ T cells. Consistent with this, PVL at 24 hours in vitro culture increased, suggesting that infected cells with higher proliferative ability increased. Analyses of provirus in a patient who received Tax-peptide pulsed dendritic cells indicate that enhanced anti-Tax immunity did not result in a decreased PVL although it inhibited recurrence of ATL. We postulate that in vivo selection, due to the immune response, cytopathic effects of HTLV-1 and intrinsic attributes of infected cells, results in the emergence of clones of HTLV-1-infected T cells that proliferate with minimized HTLV-1 antigen expression. HTLV-1 spreads in vivo through two routes: de novo infection and clonal proliferation of infected cells. Reverse transcriptase inhibitors and integrase inhibitors do not influence the PVL in HTLV-1-infected individuals, indicating that clonal proliferation is dominant to maintain and increase PVL in vivo in the chronic phase. It is assumed that the host immune responses are critical factors for clonal proliferation. We found that HTLV-1-infected clones dramatically changed during de novo infection whereas the clones in the chronic phase survived long-term after transplantation, indicating that HTLV-1-infected clones are selected for survival in vivo. Surprisingly, depletion of CD8+ cells had a small impact on PVL in a STLV-1 infected Japanese macaque, but modified the clonality of infected cells. The cells after depletion of CD8+ cells showed a higher proliferative activity during short-term in vitro culture. This study reveals that intrinsic attributes of selected clones contribute to clonal proliferation of infected cells.
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Affiliation(s)
- Mikiko Izaki
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Jun-ichirou Yasunaga
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Laboratory of Virus Control, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Kisato Nosaka
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kenji Sugata
- Laboratory of Virus Control, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Hayato Utsunomiya
- Department of Hematology, National Kyushu Cancer Center, Fukuoka, Japan
| | - Youko Suehiro
- Department of Hematology, National Kyushu Cancer Center, Fukuoka, Japan
| | - Takafumi Shichijo
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Asami Yamada
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yasuhiko Sugawara
- Department of Transplantation and Pediatric Surgery, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Taizo Hibi
- Department of Transplantation and Pediatric Surgery, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yukihiro Inomata
- Department of Transplantation and Pediatric Surgery, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hirofumi Akari
- Center for Human Evolution Modeling Research, Primate Research Institute, Kyoto University, Inuyama, Aichi, Japan
| | - Anat Melamed
- Section of Virology, Department of Medicine, Imperial College London, London, United Kingdom
| | - Charles Bangham
- Section of Virology, Department of Medicine, Imperial College London, London, United Kingdom
| | - Masao Matsuoka
- Department of Hematology, Rheumatology, and Infectious Diseases, Graduate School of Medical Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Laboratory of Virus Control, Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
- * E-mail:
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22
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Panfil AR, Green PL, Yoder KE. CRISPR Genome Editing Applied to the Pathogenic Retrovirus HTLV-1. Front Cell Infect Microbiol 2020; 10:580371. [PMID: 33425776 PMCID: PMC7785941 DOI: 10.3389/fcimb.2020.580371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 11/20/2020] [Indexed: 11/13/2022] Open
Abstract
CRISPR editing of retroviral proviruses has been limited to HIV-1. We propose human T-cell leukemia virus type 1 (HTLV-1) as an excellent model to advance CRISPR/Cas9 genome editing technologies against actively expressing and latent retroviral proviruses. HTLV-1 is a tumorigenic human retrovirus responsible for the development of both leukemia/lymphoma (ATL) and a neurological disease (HAM/TSP). The virus immortalizes and persists in CD4+ T lymphocytes that survive for the lifetime of the host. The most important drivers of HTLV-1-mediated transformation and proliferation are the tax and hbz viral genes. Tax, transcribed from the plus-sense or genome strand, is essential for de novo infection and cellular immortalization. Hbz, transcribed from the minus-strand, supports proliferation and survival of infected cells in both its protein and mRNA forms. Abrogating the function or expression of tax and/or hbz by genome editing and mutagenic double-strand break repair may disable HTLV-1-infected cell growth/survival and prevent immune modulatory effects and ultimately HTLV-1-associated disease. In addition, the HTLV-1 viral genome is highly conserved with remarkable sequence homogeneity, both within the same host and even among different HTLV isolates. This offers more focused guide RNA targeting. In addition, there are several well-established animal models for studying HTLV-1 infection in vivo as well as cell immortalization in vitro. Therefore, studies with HTLV-1 may provide a better basis to assess and advance in vivo genome editing against retroviral infections.
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Affiliation(s)
- Amanda R Panfil
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States.,Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Patrick L Green
- Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH, United States.,Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States
| | - Kristine E Yoder
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, United States.,Department of Cancer Biology and Genetics, College of Medicine, The Ohio State University, Columbus, OH, United States
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23
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Regulation of Expression and Latency in BLV and HTLV. Viruses 2020; 12:v12101079. [PMID: 32992917 PMCID: PMC7601775 DOI: 10.3390/v12101079] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/14/2022] Open
Abstract
Human T-lymphotrophic virus type 1 (HTLV-1) and Bovine leukemia virus (BLV) belong to the Deltaretrovirus genus. HTLV-1 is the etiologic agent of the highly aggressive and currently incurable cancer adult T-cell leukemia (ATL) and a neurological disease HTLV-1-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). BLV causes neoplastic proliferation of B cells in cattle: enzootic bovine leucosis (EBL). Despite the severity of these conditions, infection by HTLV-1 and BLV appear in most cases clinically asymptomatic. These viruses can undergo latency in their hosts. The silencing of proviral gene expression and maintenance of latency are central for the establishment of persistent infection, as well as for pathogenesis in vivo. In this review, we will present the mechanisms that control proviral activation and retroviral latency in deltaretroviruses, in comparison with other exogenous retroviruses. The 5′ long terminal repeats (5′-LTRs) play a main role in controlling viral gene expression. While the regulation of transcription initiation is a major mechanism of silencing, we discuss topics that include (i) the epigenetic control of the provirus, (ii) the cis-elements present in the LTR, (iii) enhancers with cell-type specific regulatory functions, (iv) the role of virally-encoded transactivator proteins, (v) the role of repressors in transcription and silencing, (vi) the effect of hormonal signaling, (vii) implications of LTR variability on transcription and latency, and (viii) the regulatory role of non-coding RNAs. Finally, we discuss how a better understanding of these mechanisms may allow for the development of more effective treatments against Deltaretroviruses.
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Kataoka K, Koya J. Clinical application of genomic aberrations in adult T-cell leukemia/lymphoma. J Clin Exp Hematop 2020; 60:66-72. [PMID: 32779615 PMCID: PMC7596910 DOI: 10.3960/jslrt.20019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Adult T-cell leukemia/lymphoma (ATL) is an aggressive peripheral T-cell malignancy with a markedly poor prognosis. The low prevalence of ATL among human T-cell leukemia virus type-1 (HTLV-1) carriers and the long latency period before ATL onset suggest that additional genetic lesions are required for ATL leukemogenesis. Recently, a large-scale genetic analysis clarified the entire picture of genetic alterations, identified a number of novel driver genes, and delineated their characteristics. Frequent alterations are observed in the molecules belonging to T-cell receptor/NF-κB signaling and other T-cell-related pathways. A notable feature of the ATL genome is the predominance of gain-of-function alterations, including activating mutations in PLCG1, PRKCB, and CARD11. As many as one-fourth of all ATL cases harbor structural variations disrupting the 3'-untranslated region of the PD-L1 gene, leading to immune evasion of tumor cells. The frequency and pattern of these somatic alterations differ among clinical subtypes. Aggressive subtypes are associated with an increased burden of genetic alterations, and higher frequencies of TP53 and IRF4 mutations, PD-L1 amplifications, and CDKN2A deletions than indolent subtypes. In contrast, STAT3 mutations are more characteristic of indolent ATL. Furthermore, these subtypes are further classified into molecularly distinct subsets with a different prognosis by genetic alterations. We present an overview of the current understanding of somatic alterations in ATL, with specific focus on their utility in clinical settings. Furthermore, we highlight their genetic features by exploring their similarities and differences among peripheral T-cell lymphomas.
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Affiliation(s)
- Keisuke Kataoka
- Division of Molecular Oncology, National Cancer Center Research Institute, Tokyo, Japan
| | - Junji Koya
- Division of Molecular Oncology, National Cancer Center Research Institute, Tokyo, Japan
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25
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Yin Yang 1 is a potent activator of human T lymphotropic virus type 1 LTR-driven gene expression via RNA binding. Proc Natl Acad Sci U S A 2020; 117:18701-18710. [PMID: 32690679 DOI: 10.1073/pnas.2005726117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Yin Yang 1 (YY1) is a DNA-binding transcription factor that either activates or represses gene expression. YY1 has previously been implicated in the transcriptional silencing of many retroviruses by binding to DNA sequences in the U3 region of the viral long terminal repeat (LTR). We here show that YY1 overexpression leads to profound activation, rather than repression, of human T lymphotropic virus type 1 (HTLV-1) expression, while YY1 down-regulation reduces HTLV-1 expression. The YY1 responsive element mapped not to YY1 DNA-binding sites in the HTLV-1 LTR but to the R region. The HTLV-1 R sequence alone is sufficient to provide YY1 responsiveness to a nonresponsive promoter, but only in the sense orientation and only when included as part of the mRNA. YY1 binds to the R region of HTLV-1 RNA in vitro and in vivo, leading to increased transcription initiation and elongation. The findings indicate that YY1 is a potent transactivator of HTLV-1 gene expression acting via binding viral RNA, rather than DNA.
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26
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Hong W, Cheng W, Zheng T, Jiang N, Xu R. AHR is a tunable knob that controls HTLV-1 latency-reactivation switching. PLoS Pathog 2020; 16:e1008664. [PMID: 32678826 PMCID: PMC7367443 DOI: 10.1371/journal.ppat.1008664] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/28/2020] [Indexed: 12/20/2022] Open
Abstract
Establishing latent infection but retaining the capability to reactivate in certain circumstance is an ingenious tactic for retroviruses to persist in vivo while evading host immune surveillance. Many evidences indicate that Human T-cell leukemia virus type 1 (HTLV-1) is not completely silent in vivo. However, signals that trigger HTLV-1 latency-reactivation switching remain poorly understood. Here, we show that aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, plays a critical role in HTLV-1 plus-strand expression. Importantly, HTLV-1 reactivation could be tunably manipulated by modulating the level of AHR ligands. Mechanistically, activated AHR binds to HTLV-1 LTR dioxin response element (DRE) site (CACGCATAT) and drives plus-strand transcription. On the other hand, persistent activation of nuclear factor kappa B (NF-κB) pathway constitutes one key prerequisite for AHR overexpression in HTLV-1 infected T-cells, setting the stage for the advent of AHR signaling. Our findings suggest that HTLV-1 might achieve its reactivation in vivo when encountering environmental, dietary, microbial and metabolic cues that induce sufficient AHR signaling. HTLV-1 is considered largely latent in vivo because viral products were rarely detected in freshly isolated PBMCs of infected individuals. However, the existence of strong HTLV-1-specific immune response in most infected individuals suggests that the virus should not be completely silent in vivo. Since viral gene expression plays a critical role in cell transformation and de novo infection, a novel insight into where and how HTLV-1 achieves its reactivation in vivo is essential for developing new therapeutic approaches. AHR is a ligand-activated transcription factor that regulates intricate transcriptional programs in response to environmental, dietary, microbial and metabolic cues. It has been reported that AHR is constitutively overexpressed in HTLV-1-infected T-cells. Nevertheless, the functional role of AHR in HTLV-1 pathogenesis is still obscure. In this study, we show that activated AHR can directly bind to HTLV-1 LTR DRE site (CACGCATAT) and drive HTLV-1 plus-strand transcription. Importantly, HTLV-1 latency-reactivation-latency switching could be manipulated in MT-1 cells by adding and removing additional kynurenine (a well-known AHR ligand). Moreover, we explicate that the persistent NF-κB activation is critical for AHR overexpression in HTLV-1-infected T-cells. These results imply that constitutive AHR overexpression in infected T-cells endues HTLV-1 the potential to reactivate from latency when the level of AHR ligands reaches a certain threshold. Accordingly, we propose that HTLV-1 might achieve its reactivation in certain parts of the body that are prone to accumulate AHR ligands.
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Affiliation(s)
- Weihao Hong
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
| | - Wenzhao Cheng
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
| | - Tingjin Zheng
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
| | - Nan Jiang
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
| | - Ruian Xu
- School of Medicine, Huaqiao University, Quanzhou, China
- Fujian Provincial Key Laboratory of Molecular Medicine & Xiamen Key Lab of Marine and Gene Drugs, Xiamen, China
- Engineering Research Center of Molecular Medicine, Ministry of Education, Xiamen, China
- * E-mail:
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