1
|
Rizvi I, Hisamuddin M, Malik A, Khan RH. Identification of mungbean yellow mosaic India virus (MYMIV) Rep interacting partners using phage display and influence of Arabidopsis thaliana MCM3 on geminivirus DNA replication. J Biomol Struct Dyn 2022; 40:10507-10517. [PMID: 34121621 DOI: 10.1080/07391102.2021.1935319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Geminiviruses consist of a single-stranded DNA genome that replicates by a rolling circle (RCR) and recombination-dependent (RDR) modes of replication. The AC1 or Rep is the indispensable viral protein required for the RCR mode of replication. Since these viruses encode only a few proteins, they depend on several host factors for replication, transcription, and other physiological processes. To get insights into the repertoire of host factors influencing the replication of geminiviruses, we performed phage display experiments which led to the identification of putative mungbean yellow mosaic India virus (MYMIV) Rep interacting host proteins. These proteins might directly or indirectly participate in geminivirus biology. MCM3 was one of the Rep-interacting partners obtained in the phage display results. Using bimolecular fluorescence complementation (BiFC), the interaction of the MYMIV Rep with Arabidopsis thaliana MCM3 (AtMCM3) was confirmed. We report the involvement of AtMCM3 in the replication of MYMIV DNA through an ex vivo system. The physiological relevance of the interaction between AtMCM3 and MYMIV Rep is reflected by yeast replication assay.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Irum Rizvi
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India.,International Centre for Genetic Engineering and Biotechnology, New Delhi, India
| | - Malik Hisamuddin
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| | - Ajamaluddin Malik
- Department of Biochemistry, King Saud University, Riyadh, Saudi Arabia
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, India
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Rushing AW, Rushing B, Hoang K, Sanders SV, Péloponèse JM, Polakowski N, Lemasson I. HTLV-1 basic leucine zipper factor protects cells from oxidative stress by upregulating expression of Heme Oxygenase I. PLoS Pathog 2019; 15:e1007922. [PMID: 31251786 PMCID: PMC6623464 DOI: 10.1371/journal.ppat.1007922] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/11/2019] [Accepted: 06/18/2019] [Indexed: 12/18/2022] Open
Abstract
Adult T-cell Leukemia (ATL) is a lymphoproliferative disease of CD4+ T-cells infected with Human T-cell Leukemia Virus type I (HTLV-1). With the exception of allogeneic hematopoietic stem cell transplantation, there are no effective treatments to cure ATL, and ATL cells often acquire resistance to conventional chemotherapeutic agents. Accumulating evidence shows that development and maintenance of ATL requires key contributions from the viral protein, HTLV-1 basic leucine zipper factor (HBZ). In this study we found that HBZ activates expression of Heme Oxygenase 1 (HMOX-1), a component of the oxidative stress response that functions to detoxify free heme. Transcription of HMOX1 and other antioxidant genes is regulated by the small Mafs. These cellular basic leucine zipper (bZIP) factors control transcription by forming homo- or heterodimers among themselves or with other cellular bZIP factors that then bind Maf responsive elements (MAREs) in promoters or enhancers of antioxidant genes. Our data support a model in which HBZ activates HMOX1 transcription by forming heterodimers with the small Mafs that bind MAREs located in an upstream enhancer region. Consistent with this model, we found that HMOX-1 is upregulated in HTLV-1-transformed T-cell lines and confers these cells with resistance to heme-induced cytotoxicity. In this context, HBZ-mediated activation of HMOX-1 expression may contribute to resistance of ATL cells to certain chemotherapeutic agents. We also provide evidence that HBZ counteracts oxidative stress caused by two other HTLV-1-encoded proteins, Tax and p13. Tax induces oxidative stress as a byproduct of driving mitotic expansion of infected cells, and p13 is believed to induce oxidative stress to eliminate infected cells that have become transformed. Therefore, in this context, HBZ-mediated activation of HMOX-1 expression may facilitate transformation. Overall, this study characterizes a novel function of HBZ that may support the development and maintenance of ATL.
Collapse
Affiliation(s)
- Amanda W. Rushing
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- * E-mail: (AWR); (IL)
| | - Blake Rushing
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Kimson Hoang
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Stephanie V. Sanders
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Jean-Marie Péloponèse
- Institut de Recherche en Infectiologie de Montpellier, Centre National de la Recherche Scientifique, Université de Montpellier, Montpellier, France
| | - Nicholas Polakowski
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Isabelle Lemasson
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
- * E-mail: (AWR); (IL)
| |
Collapse
|
4
|
Mori H, Tomiyasu T, Nishiyama K, Matsumoto M, Osawa Y, Okazaki K. L233P mutation in the bovine leukemia virus Tax protein depresses endothelial cell recruitment and tumorigenesis in athymic nude mice. Arch Virol 2019; 164:1343-1351. [DOI: 10.1007/s00705-019-04191-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 01/31/2019] [Indexed: 11/25/2022]
|
5
|
Zhu F, Qian X, Wang Z. Molecular characterization of minichromosome maintenance protein (MCM7) in Scylla paramamosain and its role in white spot syndrome virus and Vibrio alginolyticus infection. FISH & SHELLFISH IMMUNOLOGY 2018; 83:104-114. [PMID: 30205202 DOI: 10.1016/j.fsi.2018.09.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/03/2018] [Accepted: 09/07/2018] [Indexed: 06/08/2023]
Abstract
The minichromosome maintenance protein (MCM7) is a member of the MCM protein family which participates in the MCM complex by playing a role in the cell replication cycle and chromosome initiation in eukaryotes. The 2270 bp cDNA sequence of MCM7, including a 2127-bp open reading frame (ORF) encoding a 709-aa protein, was cloned from Scylla paramamosain using RT-PCR and RACE. Data showed that MCM7 was highly expressed in the digestive organ and hepatopancreas of S. paramamosain. Furthermore, MCM7 expression was down-regulated by infection with white spot syndrome virus (WSSV) or Vibrio alginolyticus. When MCM7 was knocked down, immune genes such as Janus kinase (JAK) and crustin antimicrobial peptide (CAP) were down-regulated, and C-type-lectin (CTL) was up-regulated in hemocytes. The mortality of WSSV-infected or V. alginolyticus-infected crabs was enhanced following MCM7 knockdown. It was demonstrated that MCM7 is very important in the progression of WSSV and V. alginolyticus infection. We also investigated the effect of MCM7 on apoptosis rate and phagocytic rate in S. paramamosain. MCM7 knockdown caused higher levels of apoptosis in the hemocytes of the control, WSSV, and V. alginolyticus groups. MCM7 knockdown influenced the activity of phenoloxidase (PO) and superoxide dismutase (SOD), and total hemocyte count (THC) after infection with WSSV or V. alginolyticus, which indicated that MCM7 plays a regulatory role in innate immunity of crabs. Thus, we conclude that MCM7 may participate in the anti-WSSV and V. alginolyticus immune response in crabs by regulating apoptosis and the activity of PO and SOD.
Collapse
Affiliation(s)
- Fei Zhu
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China.
| | - Xiyi Qian
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| | - Ziyan Wang
- College of Animal Science and Technology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| |
Collapse
|
6
|
Willems L, Hasegawa H, Accolla R, Bangham C, Bazarbachi A, Bertazzoni U, Carneiro-Proietti ABDF, Cheng H, Chieco-Bianchi L, Ciminale V, Coelho-Dos-Reis J, Esparza J, Gallo RC, Gessain A, Gotuzzo E, Hall W, Harford J, Hermine O, Jacobson S, Macchi B, Macpherson C, Mahieux R, Matsuoka M, Murphy E, Peloponese JM, Simon V, Tagaya Y, Taylor GP, Watanabe T, Yamano Y. Reducing the global burden of HTLV-1 infection: An agenda for research and action. Antiviral Res 2016; 137:41-48. [PMID: 27840202 DOI: 10.1016/j.antiviral.2016.10.015] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/29/2016] [Indexed: 12/27/2022]
Abstract
Even though an estimated 10-20 million people worldwide are infected with the oncogenic retrovirus, human T-lymphotropic virus type 1 (HTLV-1), its epidemiology is poorly understood, and little effort has been made to reduce its prevalence. In response to this situation, the Global Virus Network launched a taskforce in 2014 to develop new methods of prevention and treatment of HTLV-1 infection and promote basic research. HTLV-1 is the etiological agent of two life-threatening diseases, adult T-cell leukemia and HTLV-associated myelopathy/tropical spastic paraparesis, for which no effective therapy is currently available. Although the modes of transmission of HTLV-1 resemble those of the more familiar HIV-1, routine diagnostic methods are generally unavailable to support the prevention of new infections. In the present article, the Taskforce proposes a series of actions to expand epidemiological studies; increase research on mechanisms of HTLV-1 persistence, replication and pathogenesis; discover effective treatments; and develop prophylactic and therapeutic vaccines.
Collapse
Affiliation(s)
- Luc Willems
- University of Liege, Belgium; Chairs of the HTLV Taskforce of the Global Virus Network, USA.
| | - Hideki Hasegawa
- National Institute of Infectious Diseases, Tokyo, Japan; Chairs of the HTLV Taskforce of the Global Virus Network, USA
| | | | | | | | | | | | - Hua Cheng
- Institute of Human Virology, Baltimore, USA
| | | | | | | | | | | | | | - Eduardo Gotuzzo
- Tropical Medical Institute Alexander von Humboldt, Lima, Peru
| | - William Hall
- Centre for Research in Infectious Disease, Dublin, Ireland
| | | | | | - Steven Jacobson
- National Institute of Neurological Disorders and Stroke, NIH, Bethesda, USA
| | | | | | | | | | | | | | - Viviana Simon
- Icahn School of Medicine at Mount Sinai, New York, USA
| | | | | | | | | |
Collapse
|
7
|
Activation of the DNA Damage Response by RNA Viruses. Biomolecules 2016; 6:2. [PMID: 26751489 PMCID: PMC4808796 DOI: 10.3390/biom6010002] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 11/17/2015] [Accepted: 11/24/2015] [Indexed: 12/11/2022] Open
Abstract
RNA viruses are a genetically diverse group of pathogens that are responsible for some of the most prevalent and lethal human diseases. Numerous viruses introduce DNA damage and genetic instability in host cells during their lifecycles and some species also manipulate components of the DNA damage response (DDR), a complex and sophisticated series of cellular pathways that have evolved to detect and repair DNA lesions. Activation and manipulation of the DDR by DNA viruses has been extensively studied. It is apparent, however, that many RNA viruses can also induce significant DNA damage, even in cases where viral replication takes place exclusively in the cytoplasm. DNA damage can contribute to the pathogenesis of RNA viruses through the triggering of apoptosis, stimulation of inflammatory immune responses and the introduction of deleterious mutations that can increase the risk of tumorigenesis. In addition, activation of DDR pathways can contribute positively to replication of viral RNA genomes. Elucidation of the interactions between RNA viruses and the DDR has provided important insights into modulation of host cell functions by these pathogens. This review summarises the current literature regarding activation and manipulation of the DDR by several medically important RNA viruses.
Collapse
|
8
|
Bangham CRM, Ratner L. How does HTLV-1 cause adult T-cell leukaemia/lymphoma (ATL)? Curr Opin Virol 2015; 14:93-100. [PMID: 26414684 PMCID: PMC4772697 DOI: 10.1016/j.coviro.2015.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 09/09/2015] [Accepted: 09/09/2015] [Indexed: 11/21/2022]
Abstract
A typical person infected with the retrovirus human T-lymphotropic virus type 1 (HTLV-1) carries tens of thousands of clones of HTLV-1-infected T lymphocytes, each clone distinguished by a unique integration site of the provirus in the host genome. However, only 5% of infected people develop the malignant disease adult T cell leukaemia/lymphoma, usually more than 50 years after becoming infected. We review the host and viral factors that cause this aggressive disease.
Collapse
Affiliation(s)
- Charles R M Bangham
- Section of Virology, Department of Medicine, Imperial College, London W2 1PG, UK.
| | - Lee Ratner
- Medical Oncology Section, Hematology-Oncology Faculty, Washington University School of Medicine, St Louis, WA, USA
| |
Collapse
|
9
|
Nicot C. HTLV-I Tax-Mediated Inactivation of Cell Cycle Checkpoints and DNA Repair Pathways Contribute to Cellular Transformation: "A Random Mutagenesis Model". ACTA ACUST UNITED AC 2015; 2. [PMID: 26835512 DOI: 10.13188/2377-9292.1000009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To achieve cellular transformation, most oncogenic retroviruses use transduction by proto-oncogene capture or insertional mutagenesis, whereby provirus integration disrupts expression of tumor suppressors or proto-oncogenes. In contrast, the Human T-cell leukemia virus type 1 (HTLV-I) has been classified in a separate class referred to as "transactivating retroviruses". Current views suggest that the viral encoded Tax protein transactivates expression of cellular genes leading to deregulated growth and transformation. However, if Tax-mediated transactivation was indeed sufficient for cellular transformation, a fairly high frequency of infected cells would eventually become transformed. In contrast, the frequency of transformation by HTLV-I is very low, likely less than 5%. This review will discuss the current understanding and recent discoveries highlighting critical functions of Tax in cellular transformation. HTLV-I Tax carries out essential functions in order to override cell cycle checkpoints and deregulate cellular division. In addition, Tax expression is associated with increased DNA damage and genome instability. Since Tax can inhibit multiple DNA repair pathways and stimulate unfaithful DNA repair or bypass checkpoints, these processes allow accumulation of genetic mutations in the host genome. Given this, a "Random Mutagenesis" transformation model seems more suitable to characterize the oncogenic activities of HTLV-I.
Collapse
Affiliation(s)
- Christophe Nicot
- Department of Pathology and Laboratory Medicine, Center for Viral Oncology, University of Kansas Medical Center, USA
| |
Collapse
|
10
|
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that causes cancer (Adult T cell Leukemia, ATL) and a spectrum of inflammatory diseases (mainly HTLV-associated myelopathy—tropical spastic paraparesis, HAM/TSP). Since virions are particularly unstable, HTLV-1 transmission primarily occurs by transfer of a cell carrying an integrated provirus. After transcription, the viral genomic RNA undergoes reverse transcription and integration into the chromosomal DNA of a cell from the newly infected host. The virus then replicates by either one of two modes: (i) an infectious cycle by virus budding and infection of new targets and (ii) mitotic division of cells harboring an integrated provirus. HTLV-1 replication initiates a series of mechanisms in the host including antiviral immunity and checkpoint control of cell proliferation. HTLV-1 has elaborated strategies to counteract these defense mechanisms allowing continuous persistence in humans.
Collapse
|
11
|
Tumor Suppressor Inactivation in the Pathogenesis of Adult T-Cell Leukemia. JOURNAL OF ONCOLOGY 2015; 2015:183590. [PMID: 26170835 PMCID: PMC4478360 DOI: 10.1155/2015/183590] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/24/2015] [Indexed: 12/12/2022]
Abstract
Tumor suppressor functions are essential to control cellular proliferation, to activate the apoptosis or senescence pathway to eliminate unwanted cells, to link DNA damage signals to cell cycle arrest checkpoints, to activate appropriate DNA repair pathways, and to prevent the loss of adhesion to inhibit initiation of metastases. Therefore, tumor suppressor genes are indispensable to maintaining genetic and genomic integrity. Consequently, inactivation of tumor suppressors by somatic mutations or epigenetic mechanisms is frequently associated with tumor initiation and development. In contrast, reactivation of tumor suppressor functions can effectively reverse the transformed phenotype and lead to cell cycle arrest or death of cancerous cells and be used as a therapeutic strategy. Adult T-cell leukemia/lymphoma (ATLL) is an aggressive lymphoproliferative disease associated with infection of CD4 T cells by the Human T-cell Leukemia Virus Type 1 (HTLV-I). HTLV-I-associated T-cell transformation is the result of a multistep oncogenic process in which the virus initially induces chronic T-cell proliferation and alters cellular pathways resulting in the accumulation of genetic defects and the deregulated growth of virally infected cells. This review will focus on the current knowledge of the genetic and epigenetic mechanisms regulating the inactivation of tumor suppressors in the pathogenesis of HTLV-I.
Collapse
|
12
|
Discovery and characterization of auxiliary proteins encoded by type 3 simian T-cell lymphotropic viruses. J Virol 2014; 89:931-51. [PMID: 25355890 DOI: 10.1128/jvi.02150-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 encode auxiliary proteins that play important roles in viral replication, viral latency, and immune escape. The presence of auxiliary protein-encoding open reading frames (ORFs) in HTLV-3, the latest HTLV to be discovered, is unknown. Simian T-cell lymphotropic virus type 3 (STLV-3) is almost identical to HTLV-3. Given the lack of HTLV-3-infected cell lines, we took advantage of STLV-3-infected cells and of an STLV-3 molecular clone to search for the presence of auxiliary transcripts. Using reverse transcriptase PCR (RT-PCR), we first uncovered the presence of three unknown viral mRNAs encoding putative proteins of 5, 8, and 9 kDa and confirmed the presence of the previously reported RorfII transcript. The existence of these viral mRNAs was confirmed by using splice site-specific RT-PCR with ex vivo samples. We showed that p5 is distributed throughout the cell and does not colocalize with a specific organelle. The p9 localization is similar to that of HTLV-1 p12 and induced a strong decrease in the calreticulin signal, similarly to HTLV-1 p12. Although p8, RorfII, and Rex-3 share an N-terminal sequence that is predicted to contain a nucleolar localization signal (NoLS), only p8 is found in the nucleolus. The p8 location in the nucleolus is linked to a bipartite NoLS. p8 and, to a lesser extent, p9 repressed viral expression but did not alter Rex-3-dependent mRNA export. Using a transformation assay, we finally showed that none of the STLV-3 auxiliary proteins had the ability to induce colony formation, while both Tax-3 and antisense protein of HTLV-3 (APH-3) promoted cellular transformation. Altogether, these results complete the characterization of the newly described primate T-lymphotropic virus type 3 (PTLV-3). IMPORTANCE Together with their simian counterparts, HTLVs form the primate T-lymphotropic viruses. HTLVs arose from interspecies transmission between nonhuman primates and humans. HTLV-1 and HTLV-2 encode auxiliary proteins that play important roles in viral replication, viral latency, and immune escape. The presence of ORFs encoding auxiliary proteins in HTLV-3 or STLV-3 genomes was unknown. Using in silico analyses, ex vivo samples, or in vitro experiments, we have uncovered the presence of 3 previously unknown viral mRNAs encoding putative proteins and confirmed the presence of a previously reported viral transcript. We characterized the intracellular localization of the four proteins. We showed that two of these proteins repress viral expression but that none of them have the ability to induce colony formation. However, both Tax and the antisense protein APH-3 promote cell transformation. Our results allowed us to characterize 4 new retroviral proteins for the first time.
Collapse
|
13
|
Chaib-Mezrag H, Lemaçon D, Fontaine H, Bellon M, Bai XT, Drac M, Coquelle A, Nicot C. Tax impairs DNA replication forks and increases DNA breaks in specific oncogenic genome regions. Mol Cancer 2014; 13:205. [PMID: 25185513 PMCID: PMC4168069 DOI: 10.1186/1476-4598-13-205] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 08/26/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Human T-cell leukemia virus type 1 (HTLV-I) is a human retrovirus associated with adult T-cell leukemia (ATL), an aggressive CD4 T-cell proliferative disease with dismal prognosis. The long latency preceding the development of the disease and the low incidence suggests that the virus itself is not sufficient for transformation and that genetic defects are required to create a permissive environment for leukemia. In fact, ATL cells are characterized by profound genetic modifications including structural and numerical chromosome alterations. RESULTS In this study we used molecular combing techniques to study the effect of the oncoprotein Tax on DNA replication. We found that replication forks have difficulties replicating complex DNA, fork progression is slower, and they pause or stall more frequently in the presence of Tax expression. Our results also show that Tax-associated replication defects are partially compensated by an increase in the firing of back-up origins. Consistent with these effects of Tax on DNA replication, an increase in double strand DNA breaks (DDSB) was seen in Tax expressing cells. Tax-mediated increases in DDSBs were associated with the ability of Tax to activate NF-kB and to stimulate intracellular nitric oxide production. We also demonstrated a reduced expression of human translesion synthesis (TLS) DNA polymerases Pol-H and Pol-K in HTLV-I-transformed T cells and ATL cells. This was associated with an increase in DNA breaks induced by Tax at specific genome regions, such as the c-Myc and the Bcl-2 major breakpoints. Consistent with the notion that the non-homologous end joining (NHEJ) pathway is hyperactive in HTLV-I-transformed cells, we found that inhibition of the NHEJ pathway induces significant killing of HTLV-I transformed cells and patient-derived leukemic ATL cells. CONCLUSION Our results suggest that, replication problems increase genetic instability in HTLV-I-transformed cells. As a result, abuse of NHEJ and a defective homologous repair (HR) DNA repair pathway can be targeted as a new therapeutic approach for the treatment of adult T-cell leukemia.
Collapse
Affiliation(s)
- Hassiba Chaib-Mezrag
- />Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 USA
| | - Delphine Lemaçon
- />IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298 France
- />INSERM, U896, Montpellier, F-34298 France
- />Université Montpellier 1, Montpellier, F-34298 France
- />Institut régional du Cancer Montpellier, Montpellier, F-34298 France
| | - Hélène Fontaine
- />IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298 France
- />INSERM, U896, Montpellier, F-34298 France
- />Université Montpellier 1, Montpellier, F-34298 France
- />Institut régional du Cancer Montpellier, Montpellier, F-34298 France
| | - Marcia Bellon
- />Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 USA
| | - Xue Tao Bai
- />Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 USA
| | - Marjorie Drac
- />DNA Combing Facility, Institut de Génétique Moléculaire, CNRS UMR5535 & BioCampus Montpellier (UMS3426), 1919 route de Mende, Montpellier cedex 5, 34293 France
| | - Arnaud Coquelle
- />IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier, F-34298 France
- />INSERM, U896, Montpellier, F-34298 France
- />Université Montpellier 1, Montpellier, F-34298 France
- />Institut régional du Cancer Montpellier, Montpellier, F-34298 France
| | - Christophe Nicot
- />Department of Pathology and Laboratory Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160 USA
| |
Collapse
|
14
|
Gutiérrez G, Rodríguez SM, de Brogniez A, Gillet N, Golime R, Burny A, Jaworski JP, Alvarez I, Vagnoni L, Trono K, Willems L. Vaccination against δ-retroviruses: the bovine leukemia virus paradigm. Viruses 2014; 6:2416-27. [PMID: 24956179 PMCID: PMC4074934 DOI: 10.3390/v6062416] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 02/07/2023] Open
Abstract
Bovine leukemia virus (BLV) and human T-lymphotropic virus type 1 (HTLV-1) are closely related δ-retroviruses that induce hematological diseases. HTLV-1 infects about 15 million people worldwide, mainly in subtropical areas. HTLV-1 induces a wide spectrum of diseases (e.g., HTLV-associated myelopathy/tropical spastic paraparesis) and leukemia/lymphoma (adult T-cell leukemia). Bovine leukemia virus is a major pathogen of cattle, causing important economic losses due to a reduction in production, export limitations and lymphoma-associated death. In the absence of satisfactory treatment for these diseases and besides the prevention of transmission, the best option to reduce the prevalence of δ-retroviruses is vaccination. Here, we provide an overview of the different vaccination strategies in the BLV model and outline key parameters required for vaccine efficacy.
Collapse
Affiliation(s)
- Gerónimo Gutiérrez
- Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA, C.C. 1712, Castelar, Argentina.
| | - Sabrina M Rodríguez
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Alix de Brogniez
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Nicolas Gillet
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Ramarao Golime
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Arsène Burny
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| | - Juan-Pablo Jaworski
- Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA, C.C. 1712, Castelar, Argentina.
| | - Irene Alvarez
- Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA, C.C. 1712, Castelar, Argentina.
| | - Lucas Vagnoni
- Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA, C.C. 1712, Castelar, Argentina.
| | - Karina Trono
- Instituto de Virología, Centro de Investigaciones en Ciencias Veterinarias y Agronómicas, INTA, C.C. 1712, Castelar, Argentina.
| | - Luc Willems
- Molecular and Cellular Epigenetics (GIGA) and Molecular Biology (Gembloux Agro-Bio Tech), University of Liège (ULg), 4000 Liège, Belgium.
| |
Collapse
|
15
|
Inoue E, Matsumura K, Soma N, Hirasawa S, Wakimoto M, Arakaki Y, Yoshida T, Osawa Y, Okazaki K. L233P mutation of the Tax protein strongly correlated with leukemogenicity of bovine leukemia virus. Vet Microbiol 2013; 167:364-71. [PMID: 24139177 DOI: 10.1016/j.vetmic.2013.09.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 09/11/2013] [Accepted: 09/17/2013] [Indexed: 10/26/2022]
Abstract
The bovine leukemia virus (BLV) Tax protein is believed to play a crucial role in leukemogenesis by the virus. BLV usually causes asymptomatic infections in cattle, but only one-third develop persistent lymphocytosis that rarely progress after a long incubation period to lymphoid tumors, namely enzootic bovine leucosis (EBL). In the present study, we demonstrated that the BLV tax genes could be divided into two alleles and developed multiplex PCR detecting an L233P mutation of the Tax protein. Then, in order to define the relationship between the Tax protein and leukemogenicity, we examined 360 tumor samples randomly collected from dairy or breeding cattle in Japan, of which Tax proteins were categorized, for age at the time of diagnosis of EBL. The ages of 288 animals (80.0%) associated with L233-Tax and those of 70 animals (19.4%) with P233-Tax individually followed log-normal distributions. Only the two earliest cases (0.6%) with L233-Tax disobeyed the log-normal distribution. These findings suggest that the animals affected by EBL were infected with the virus at a particular point in life, probably less than a few months after birth. Median age of those with P233-Tax was 22 months older than that with L233-Tax and geometric means exhibited a significant difference (P<0.01). It is also quite unlikely that viruses carrying the particular Tax protein infect older cattle. Here, we conclude that BLV could be divided into two categories on the basis of amino acid at position 233 of the Tax protein, which strongly correlated with leukemogenicity.
Collapse
Affiliation(s)
- Emi Inoue
- Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido 061-0293, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Lodewick J, Sampaio C, Boxus M, Rinaldi AS, Coulonval K, Willems L, Roger PP, Bex F. Acetylation at lysine 346 controls the transforming activity of the HTLV-1 Tax oncoprotein in the Rat-1 fibroblast model. Retrovirology 2013; 10:75. [PMID: 23880157 PMCID: PMC3734113 DOI: 10.1186/1742-4690-10-75] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 07/18/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Transformation by the Tax oncoprotein of the human T cell leukemia virus type 1 (HTLV-1) is governed by actions on cellular regulatory signals, including modulation of specific cellular gene expression via activation of signaling pathways, acceleration of cell cycle progression via stimulation of cyclin-dependent kinase activity leading to retinoblastoma protein (pRb) hyperphosphorylation and perturbation of survival signals. These actions control early steps in T cell transformation and development of Adult T cell leukemia (ATL), an aggressive malignancy of HTLV-1 infected T lymphocytes. Post-translational modifications of Tax by phosphorylation, ubiquitination, sumoylation and acetylation have been implicated in Tax-mediated activation of the NF-κB pathway, a key function associated with Tax transforming potential. RESULTS In this study, we demonstrate that acetylation at lysine K(346) in the carboxy-terminal domain of Tax is modulated in the Tax nuclear bodies by the acetyltransferase p300 and the deacetylases HDAC5/7 and controls phosphorylation of the tumor suppressor pRb by Tax-cyclin D3-CDK4-p21(CIP) complexes. This property correlates with the inability of the acetylation deficient K(346)R mutant, but not the acetylation mimetic K(346)Q mutant, to promote anchorage-independent growth of Rat-1 fibroblasts. By contrast, acetylation at lysine K(346) had no effects on the ability of Tax carboxy-terminal PDZ-binding domain to interact with the tumor suppressor hDLG. CONCLUSIONS The identification of the acetyltransferase p300 and the deacetylase HDAC7 as enzymes modulating Tax acetylation points to new therapeutic targets for the treatment of HTLV-1 infected patients at risk of developing ATL.
Collapse
Affiliation(s)
- Julie Lodewick
- Institute for Microbiological Research J-M Wiame (IRMW), Laboratory of Microbiology, Université Libre de Bruxelles, 1, Avenue E, Gryson, Brussels, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Gillet N, Carpentier A, Barez PY, Willems L. WIP1 deficiency inhibits HTLV-1 Tax oncogenesis: novel therapeutic prospects for treatment of ATL? Retrovirology 2012; 9:115. [PMID: 23256570 PMCID: PMC3542286 DOI: 10.1186/1742-4690-9-115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 12/15/2012] [Indexed: 02/01/2023] Open
Abstract
Attenuation of p53 activity appears to be a major step in Human T-lymphotropic virus type 1 (HTLV-1) Tax transformation. However, p53 genomic mutations are late and rather infrequent events in HTLV-1 induced Adult T cell leukemia (ATL). The paper by Zane et al. shows that a mediator of p53 activity, Wild-type p53-induced phosphatase 1 (Wip1), contributes to Tax-induced oncogenesis in a mouse model. Wip1 may therefore be a novel target for therapeutic approaches.
Collapse
Affiliation(s)
- Nicolas Gillet
- Molecular and Cellular Epigenetics, GIGA, University of Liège, Liège, Belgium
| | | | | | | |
Collapse
|
18
|
Currer R, Van Duyne R, Jaworski E, Guendel I, Sampey G, Das R, Narayanan A, Kashanchi F. HTLV tax: a fascinating multifunctional co-regulator of viral and cellular pathways. Front Microbiol 2012; 3:406. [PMID: 23226145 PMCID: PMC3510432 DOI: 10.3389/fmicb.2012.00406] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Accepted: 11/12/2012] [Indexed: 12/18/2022] Open
Abstract
Human T-cell lymphotropic virus type 1 (HTLV-1) has been identified as the causative agent of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The virus infects between 15 and 20 million people worldwide of which approximately 2-5% develop ATL. The past 35 years of research have yielded significant insight into the pathogenesis of HTLV-1, including the molecular characterization of Tax, the viral transactivator, and oncoprotein. In spite of these efforts, the mechanisms of oncogenesis of this pleiotropic protein remain to be fully elucidated. In this review, we illustrate the multiple oncogenic roles of Tax by summarizing a recent body of literature that refines our understanding of cellular transformation. A focused range of topics are discussed in this review including Tax-mediated regulation of the viral promoter and other cellular pathways, particularly the connection of the NF-κB pathway to both post-translational modifications (PTMs) of Tax and subcellular localization. Specifically, recent research on polyubiquitination of Tax as it relates to the activation of the IkappaB kinase (IKK) complex is highlighted. Regulation of the cell cycle and DNA damage responses due to Tax are also discussed, including Tax interaction with minichromosome maintenance proteins and the role of Tax in chromatin remodeling. The recent identification of HTLV-3 has amplified the importance of the characterization of emerging viral pathogens. The challenge of the molecular determination of pathogenicity and malignant disease of this virus lies in the comparison of the viral transactivators of HTLV-1, -2, and -3 in terms of transformation and immortalization. Consequently, differences between the three proteins are currently being studied to determine what factors are required for the differences in tumorogenesis.
Collapse
Affiliation(s)
- Robert Currer
- National Center for Biodefense and Infectious Diseases, George Mason University Manassas, VA, USA
| | | | | | | | | | | | | | | |
Collapse
|
19
|
The cellular autophagy pathway modulates human T-cell leukemia virus type 1 replication. J Virol 2012; 87:1699-707. [PMID: 23175371 DOI: 10.1128/jvi.02147-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Autophagy, a general homeostatic process for degradation of cytosolic proteins or organelles, has been reported to modulate the replication of many viruses. The role of autophagy in human T-cell leukemia virus type 1 (HTLV-1) replication has, however, been uncharacterized. Here, we report that HTLV-1 infection increases the accumulation of autophagosomes and that this accumulation increases HTLV-1 production. We found that the HTLV-1 Tax protein increases cellular autophagosome accumulation by acting to block the fusion of autophagosomes to lysosomes, preventing the degradation of the former by the latter. Interestingly, the inhibition of cellular autophagosome-lysosome fusion using bafilomycin A increased the stability of the Tax protein, suggesting that cellular degradation of Tax occurs in part through autophagy. Our current findings indicate that by interrupting the cell's autophagic process, Tax exerts a positive feedback on its own stability.
Collapse
|
20
|
HTLV-I tax increases genetic instability by inducing DNA double strand breaks during DNA replication and switching repair to NHEJ. PLoS One 2012; 7:e42226. [PMID: 22916124 PMCID: PMC3423393 DOI: 10.1371/journal.pone.0042226] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 07/02/2012] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Appropriate responses to damaged DNA are indispensible for preserving genome stability and preventing cancer. Tumor viruses often target DNA repair machinery to achieve transformation. The Human T-cell leukemia virus type I (HTLV-I) is the only known transforming human retrovirus and the etiological agent of Adult T-cell Leukemia (ATLL). Although HTLV-I-transformed leukemic cells have numerous genetic lesions, the precise role of the viral tax gene in this process is not fully understood. RESULTS Our results show a novel function of HTLV-I oncoprotein Tax as an inducer of genomic DNA double strand breaks (DDSB) during DNA replication. We also found that Tax acts as a potent inhibitor of homologous recombination (HR) DNA repair through the activation of the NF-kB pathway. These results were confirmed using HTLV-I molecular clones expressing Tax at physiological levels in a natural context. We further found that HTLV-I- and Tax-transformed cells are not more susceptible to DNA damaging agents and repair DNA lesions at a rate similar to that of normal cells. Finally, we demonstrated that during S phase, Tax-associated DDSB are preferentially repaired using the error-prone non-homologous end joining (NHEJ) pathway. CONCLUSIONS This study provides new insights in Tax effects on DNA repair and genome instability. Although it may not be self sufficient, the creation of DNA breaks and subsequent abnormal use of the non-conservative NHEJ DNA repair during the S phase in HTLV-I-infected Tax-expressing cells may cooperate with other factors to increase genetic and genome instability and favor transformation.
Collapse
|
21
|
Boxus M, Willems L. How the DNA damage response determines the fate of HTLV-1 Tax-expressing cells. Retrovirology 2012; 9:2. [PMID: 22221708 PMCID: PMC3283471 DOI: 10.1186/1742-4690-9-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/05/2012] [Indexed: 11/10/2022] Open
Abstract
How the Human T lymphotropic virus type 1 (HTLV-1) Tax protein stimulates proliferation while triggering cell cycle arrest and senescence remains puzzling. There is also a debate about the ability of Tax to activate or inhibit the DNA damage response. Here, we comment on these different activities and propose a conceptual rationale for the apparently conflicting observations.
Collapse
Affiliation(s)
- Mathieu Boxus
- National Fund for Scientific Research, Gembloux Agro-Bio Tech and Interdisciplinary Cluster for Applied Genoproteomics (GIGA), University of Liège, Belgium
| | | |
Collapse
|
22
|
Martin F, Bangham CRM, Ciminale V, Lairmore MD, Murphy EL, Switzer WM, Mahieux R. Conference highlights of the 15th International Conference on Human Retrovirology: HTLV and related retroviruses, 4-8 June 2011, Leuven, Gembloux, Belgium. Retrovirology 2011; 8:86. [PMID: 22035054 PMCID: PMC3223150 DOI: 10.1186/1742-4690-8-86] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 10/28/2011] [Indexed: 12/27/2022] Open
Abstract
The June 2011 15th International Conference on Human Retrovirology: HTLV and Related Viruses marks approximately 30 years since the discovery of HTLV-1. As anticipated, a large number of abstracts were submitted and presented by scientists, new and old to the field of retrovirology, from all five continents. The aim of this review is to distribute the scientific highlights of the presentations as analysed and represented by experts in specific fields of epidemiology, clinical research, immunology, animal models, molecular and cellular biology, and virology.
Collapse
Affiliation(s)
- Fabiola Martin
- Centre for Immunology and Infection, Department of Biology, Hull and York Medical School, University of York, York, UK
| | - Charles RM Bangham
- Department of Immunology, Wright-Fleming Institute, Imperial College London, London, UK
| | - Vincenzo Ciminale
- Department of Oncology and Surgical Sciences and Istituto Oncologico Veneto-Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Padova, Italy
| | - Michael D Lairmore
- Department of Veterinary Biosciences; Centre for Retrovirus Research; and Comprehensive Cancer Centre, The Arthur James Cancer Hospital and Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Edward L Murphy
- University of California San Francisco and Blood Systems Research Institute, San Francisco, California, USA
| | - William M Switzer
- Laboratory Branch, Division of HIV/AIDS Prevention, National Centre for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centres for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Renaud Mahieux
- Retroviral Oncogenesis Laboratory, INSERM-U758 Human Virology, 69364 Lyon cedex 07, France
- Ecole Normale Supérieure de Lyon, 69364 Lyon cedex 07, France
| |
Collapse
|