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Fajami Z, Akbarin MM, Rafatpanah H, Ramezani S, Rahimi H, Rezaee SA. Assessment of Bcl-xL, TAX, and HBZ Gene Expression in Adult T cell Leukemia/Lymphoma Patients. AIDS Res Hum Retroviruses 2024; 40:141-147. [PMID: 37565279 DOI: 10.1089/aid.2023.0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023] Open
Abstract
Adult T cell leukemia/lymphoma is a malignancy with a poor prognosis caused by human T lymphocyte virus type 1 (HTLV-1) infection. Tax and HBZ are two major viral proteins that may be involved in oncogenesis by disrupting apoptosis. Because Bcl-xL plays an integral role in the anti-apoptotic pathway, this study examines the interaction between host apoptosis and oncoproteins. We investigated 37 HTLV-1-infected individuals, including 18 asymptomatic and 19 adult T cell leukemia/lymphoma (ATLL) subjects. mRNA was extracted and converted to cDNA from peripheral blood mononuclear cells, and then gene expression was determined using TaqMan q-PCR. Moreover, the HTLV-1 proviral load (PVL) was also measured using a commercial absolute quantification kit (Novin Gene, Iran). Data analysis revealed that the mean of TAX, HBZ, and PVL was significantly higher among the study groups (ATLL and carrier groups p = .003, p = .000, and p = .002 respectively). There was no statistical difference in Bcl-xL gene expression between the study groups (p = .323). It is proposed that this anti-apoptotic pathway may not be directly involved in the development of ATLL lymphoma. Bcl-xL, TAX, HBZ gene expression, and PVL can be utilized as prognostic markers.
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Affiliation(s)
- Zahra Fajami
- Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Mehdi Akbarin
- Inflammation and Inflammatory Diseases Research Centre, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Houshang Rafatpanah
- Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Samaneh Ramezani
- Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Rahimi
- Department of Hematology, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyed Abdolrahim Rezaee
- Department of Modern Sciences and Technologies, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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2
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Marino-Merlo F, Grelli S, Mastino A, Lai M, Ferrari P, Nicolini A, Pistello M, Macchi B. Human T-Cell Leukemia Virus Type 1 Oncogenesis between Active Expression and Latency: A Possible Source for the Development of Therapeutic Targets. Int J Mol Sci 2023; 24:14807. [PMID: 37834255 PMCID: PMC10572738 DOI: 10.3390/ijms241914807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 09/16/2023] [Accepted: 09/28/2023] [Indexed: 10/15/2023] Open
Abstract
The human T-cell leukemia virus type 1 (HTLV-1) is the only known human oncogenic retrovirus. HTLV-1 can cause a type of cancer called adult T-cell leukemia/lymphoma (ATL). The virus is transmitted through the body fluids of infected individuals, primarily breast milk, blood, and semen. At least 5-10 million people in the world are infected with HTLV-1. In addition to ATL, HTLV-1 infection can also cause HTLV-I-associated myelopathy (HAM/TSP). ATL is characterized by a low viral expression and poor prognosis. The oncogenic mechanism triggered by HTLV-1 is extremely complex and the molecular pathways are not fully understood. However, viral regulatory proteins Tax and HTLV-1 bZIP factor (HBZ) have been shown to play key roles in the transformation of HTLV-1-infected T cells. Moreover, several studies have shown that the final fate of HTLV-1-infected transformed Tcell clones is the result of a complex interplay of HTLV-1 oncogenic protein expression with cellular transcription factors that subvert the cell cycle and disrupt regulated cell death, thereby exerting their transforming effects. This review provides updated information on the mechanisms underlying the transforming action of HTLV-1 and highlights potential therapeutic targets to combat ATL.
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Affiliation(s)
- Francesca Marino-Merlo
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, 98166 Messina, Italy;
| | - Sandro Grelli
- Department of Experimental Medicine, University of Rome “Tor Vergata”, 00133 Rome, Italy;
| | - Antonio Mastino
- The Institute of Translational Pharmacology, CNR, 00133 Rome, Italy;
| | - Michele Lai
- Retrovirus Center and Virology Section, Department of Translational Research, University of Pisa, 56100 Pisa, Italy; (M.L.); (M.P.)
| | - Paola Ferrari
- Unit of Oncology, Department of Medical and Oncological Area, Azienda Ospedaliera—Universitaria Pisana, 56125 Pisa, Italy;
| | - Andrea Nicolini
- Department of Oncology, Transplantations and New Technologies in Medicine, University of Pisa, 56126 Pisa, Italy
| | - Mauro Pistello
- Retrovirus Center and Virology Section, Department of Translational Research, University of Pisa, 56100 Pisa, Italy; (M.L.); (M.P.)
| | - Beatrice Macchi
- Department of Chemical Science and Technology, University of Rome “Tor Vergata”, 00133 Rome, Italy;
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3
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Polakowski N, Sarker MAK, Hoang K, Boateng G, Rushing AW, Kendle W, Pique C, Green PL, Panfil AR, Lemasson I. HBZ upregulates myoferlin expression to facilitate HTLV-1 infection. PLoS Pathog 2023; 19:e1011202. [PMID: 36827461 PMCID: PMC9994761 DOI: 10.1371/journal.ppat.1011202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/08/2023] [Accepted: 02/10/2023] [Indexed: 02/26/2023] Open
Abstract
The complex retrovirus, human T-cell leukemia virus type 1 (HTLV-1), primarily infects CD4+ T-cells in vivo. Infectious spread within this cell population requires direct contact between virally-infected and target cells. The HTLV-1 accessory protein, HBZ, was recently shown to enhance HTLV-1 infection by activating intracellular adhesion molecule 1 (ICAM-1) expression, which promotes binding of infected cells to target cells and facilitates formation of a virological synapse. In this study we show that HBZ additionally enhances HTLV-1 infection by activating expression of myoferlin (MyoF), which functions in membrane fusion and repair and vesicle transport. Results from ChIP assays and quantitative reverse transcriptase PCR indicate that HBZ forms a complex with c-Jun or JunB at two enhancer sites within the MYOF gene and activates transcription through recruitment of the coactivator p300/CBP. In HTLV-1-infected T-cells, specific inhibition of MyoF using the drug, WJ460, or shRNA-mediated knockdown of MyoF reduced infection efficiency. This effect was associated with a decrease in cell adhesion and an intracellular reduction in the abundance of HTLV-1 envelope (Env) surface unit (SU) and transmembrane domain (TM). Lysosomal protease inhibitors partially restored SU levels in WJ460-treated cells, and SU localization to LAMP-2 sites was increased by MyoF knockdown, suggesting that MyoF restricts SU trafficking to lysosomes for degradation. Consistent with these effects, less SU was associated with cell-free virus particles. Together, these data suggest that MyoF contributes to HTLV-1 infection through modulation of Env trafficking and cell adhesion.
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Affiliation(s)
- Nicholas Polakowski
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
| | - Md Abu Kawsar Sarker
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
| | - Kimson Hoang
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
| | - Georgina Boateng
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
| | - Amanda W. Rushing
- Catawba College, Department of Biology, Salisbury, North Carolina, United States of America
| | - Wesley Kendle
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
| | - Claudine Pique
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS, UMR8104, Paris, France
- Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Patrick L. Green
- Center for Retrovirus Research and Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Amanda R. Panfil
- Center for Retrovirus Research and Department of Veterinary Biosciences, College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Isabelle Lemasson
- Brody School of Medicine, Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, United States of America
- * E-mail:
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Shallak M, Alberio T, Fasano M, Monti M, Iacobucci I, Ladet J, Mortreux F, Accolla RS, Forlani G. The endogenous HBZ interactome in ATL leukemic cells reveals an unprecedented complexity of host interacting partners involved in RNA splicing. Front Immunol 2022; 13:939863. [PMID: 35979358 PMCID: PMC9376625 DOI: 10.3389/fimmu.2022.939863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Adult T-cell leukemia/lymphoma (ATL) is a T-cell lymphoproliferative neoplasm caused by the human T-cell leukemia virus type 1 (HTLV-1). Two viral proteins, Tax-1 and HBZ play important roles in HTLV-1 infectivity and in HTLV-1-associated pathologies by altering key pathways of cell homeostasis. However, the molecular mechanisms through which the two viral proteins, particularly HBZ, induce and/or sustain the oncogenic process are still largely elusive. Previous results suggested that HBZ interaction with nuclear factors may alter cell cycle and cell proliferation. To have a more complete picture of the HBZ interactions, we investigated in detail the endogenous HBZ interactome in leukemic cells by immunoprecipitating the HBZ-interacting complexes of ATL-2 leukemic cells, followed by tandem mass spectrometry analyses. RNA seq analysis was performed to decipher the differential gene expression and splicing modifications related to HTLV-1. Here we compared ATL-2 with MOLT-4, a non HTLV-1 derived leukemic T cell line and further compared with HBZ-induced modifications in an isogenic system composed by Jurkat T cells and stably HBZ transfected Jurkat derivatives. The endogenous HBZ interactome of ATL-2 cells identified 249 interactors covering three main clusters corresponding to protein families mainly involved in mRNA splicing, nonsense-mediated RNA decay (NMD) and JAK-STAT signaling pathway. Here we analyzed in detail the cluster involved in RNA splicing. RNAseq analysis showed that HBZ specifically altered the transcription of many genes, including crucial oncogenes, by affecting different splicing events. Consistently, the two RNA helicases, members of the RNA splicing family, DDX5 and its paralog DDX17, recently shown to be involved in alternative splicing of cellular genes after NF-κB activation by HTLV-1 Tax-1, interacted and partially co-localized with HBZ. For the first time, a complete picture of the endogenous HBZ interactome was elucidated. The wide interaction of HBZ with molecules involved in RNA splicing and the subsequent transcriptome alteration strongly suggests an unprecedented complex role of the viral oncogene in the establishment of the leukemic state.
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Affiliation(s)
- Mariam Shallak
- Laboratories of General Pathology and Immunology “Giovanna Tosi”, Department of Medicine and Surgery, University of Insubria, Varese, Italy
| | - Tiziana Alberio
- Laboratory of Biochemistry and Functional Proteomics, Department of Science and High Technology, University of Insubria, Busto Arsizio, Italy
| | - Mauro Fasano
- Laboratory of Biochemistry and Functional Proteomics, Department of Science and High Technology, University of Insubria, Busto Arsizio, Italy
| | - Maria Monti
- Department of Chemical Sciences, University Federico II of Naples, Naples, Italy
- CEINGE Advanced Biotechnologies, Naples, Italy
| | - Ilaria Iacobucci
- Department of Chemical Sciences, University Federico II of Naples, Naples, Italy
- CEINGE Advanced Biotechnologies, Naples, Italy
| | - Julien Ladet
- Laboratory of Biology and Modeling of the Cell, CNRS UMR 5239, INSERM U1210, University of Lyon, Lyon, France
| | - Franck Mortreux
- Laboratory of Biology and Modeling of the Cell, CNRS UMR 5239, INSERM U1210, University of Lyon, Lyon, France
- *Correspondence: Franck Mortreux, ; Roberto S. Accolla, ; Greta Forlani,
| | - Roberto S. Accolla
- Laboratories of General Pathology and Immunology “Giovanna Tosi”, Department of Medicine and Surgery, University of Insubria, Varese, Italy
- *Correspondence: Franck Mortreux, ; Roberto S. Accolla, ; Greta Forlani,
| | - Greta Forlani
- Laboratories of General Pathology and Immunology “Giovanna Tosi”, Department of Medicine and Surgery, University of Insubria, Varese, Italy
- *Correspondence: Franck Mortreux, ; Roberto S. Accolla, ; Greta Forlani,
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El Hajj H, Bazarbachi A. Interplay between innate immunity and the viral oncoproteins Tax and HBZ in the pathogenesis and therapeutic response of HTLV-1 associated adult T cell leukemia. Front Immunol 2022; 13:957535. [PMID: 35935975 PMCID: PMC9352851 DOI: 10.3389/fimmu.2022.957535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 06/27/2022] [Indexed: 11/24/2022] Open
Abstract
The Human T-cell Leukemia virus type 1 (HTLV-1) causes an array of pathologies, the most aggressive of which is adult T-cell leukemia (ATL), a fatal blood malignancy with dismal prognosis. The progression of these diseases is partly ascribed to the failure of the immune system in controlling the spread of virally infected cells. HTLV-1 infected subjects, whether asymptomatic carriers or symptomatic patients are prone to opportunistic infections. An increasing body of literature emphasizes the interplay between HTLV-1, its associated pathologies, and the pivotal role of the host innate and adoptive immune system, in shaping the progression of HTLV-1 associated diseases and their response to therapy. In this review, we will describe the modalities adopted by the malignant ATL cells to subvert the host innate immune response with emphasis on the role of the two viral oncoproteins Tax and HBZ in this process. We will also provide a comprehensive overview on the function of innate immunity in the therapeutic response to chemotherapy, anti-viral or targeted therapies in the pre-clinical and clinical settings.
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Affiliation(s)
- Hiba El Hajj
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - 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
- *Correspondence: Ali Bazarbachi,
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6
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Accolla RS. The Road to HTLV-1-Induced Leukemia by Following the Subcellular Localization of HTLV-1-Encoded HBZ Protein. Front Immunol 2022; 13:940131. [PMID: 35812456 PMCID: PMC9259882 DOI: 10.3389/fimmu.2022.940131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
Human T cell leukemia virus-1 (HTLV-1) is the causative agent of a severe cancer of the lymphoid lineage that develops in 3-5% of infected individuals after many years. HTLV-1 infection may also induce a serious inflammatory pathology of the nervous system designated HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Two virus-encoded proteins, the viral transactivator Tax-1 and the HTLV-1 basic leucine-zipper factor HBZ, are strongly involved in the oncogenic process. Tax-1 is involved in initial phases of the oncogenic process. Conversely, HBZ seems to be involved in maintenance of the neoplastic state as witnessed by the generation of leukemic/lymphomatous phenotype in HBZ transgenic mice and the persistent expression of HBZ in all phases of the oncogenic process. Nevertheless, the intimate molecular and cellular mechanism mediated by the two viral proteins, particularly HBZ, in oncogenesis still remain elusive. An important step toward the complete comprehension of HBZ-associated oncogenicity is the clarification of the anatomical correlates of HBZ during the various phases of HTLV-1 infection to development of HTLV-1-associated inflammatory pathology and ultimately to the establishment of leukemia. In this review, I will summarize recent studies that have established for the first time a temporal and unidirectional expression of HBZ, beginning with an exclusive cytoplasmic localization in infected asymptomatic individuals and in HAM/TSP patients and ending to a progressive cytoplasmic-to-nuclear transition in leukemic cells. These results are framed within the present knowledge of HTLV-1 infection and the future lines of research that may shed new light on the complex mechanism of HTLV-1- mediated oncogenesis.
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Abstract
Exogenous retroviruses such as human immunodeficiency virus type 1 (HIV-1), human T-cell leukemia virus type 1 (HTLV-1) and bovine leukemia virus (BLV) can cause various diseases including immunodeficiency, inflammatory diseases and hematologic malignancies. These retroviruses persistently infect their hosts. Therefore, they need to evade host immune surveillance. One way in which these viruses might avoid immune detection is to utilize functional RNAs, rather than proteins, for certain activities, because RNAs are not recognized by the host immune system. HTLV-1 encodes the HTLV-1 bZIP factor (HBZ) gene in the antisense strand of the provirus. The HBZ protein is constantly expressed in HTLV-1 carriers and patients with adult T-cell leukemia-lymphoma, and it plays critical roles in pathogenesis. However, HBZ not only encodes this protein, but also functions as mRNA. Thus, HBZ gene mRNA is bifunctional. HIV-1 and BLV also encode long non-coding RNAs as antisense transcripts. In this review, we reshape our current understanding of how these antisense transcripts function and how they influence disease pathogenesis.
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Rein A. Stephen Oroszlan and Retroviral Proteins. Viruses 2022; 14:v14020290. [PMID: 35215882 PMCID: PMC8878580 DOI: 10.3390/v14020290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 12/04/2022] Open
Affiliation(s)
- Alan Rein
- HIV Dynamics and Replication Program, National Cancer Institute, Frederick, MD 21702, USA
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Nakamura H, Tsukamoto M, Nagasawa Y, Kitamura N, Shimizu T, Kawakami A, Nagata K, Takei M. Does HTLV-1 Infection Show Phenotypes Found in Sjögren's Syndrome? Viruses 2022; 14:v14010100. [PMID: 35062304 PMCID: PMC8780498 DOI: 10.3390/v14010100] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/04/2022] [Accepted: 01/05/2022] [Indexed: 12/17/2022] Open
Abstract
Viruses are a possible cause for Sjögren’s syndrome (SS) as an environmental factor related to SS onset, which exhibits exocrine gland dysfunction and the emergence of autoantibodies. Although retroviruses may exhibit lymphocytic infiltration into exocrine glands, human T-cell leukemia virus type 1 (HTLV-1) has been postulated to be a causative agent for SS. Transgenic mice with HTLV-1 genes showed sialadenitis resembling SS, but their phenotypic symptoms differed based on the adopted region of HTLV-1 genes. The dominance of tax gene differed in labial salivary glands (LSGs) of SS patients with HTLV 1-associated myelopathy (HAM) and adult T-cell leukemia. Although HTLV-1 was transmitted to salivary gland epithelial cells (SGECs) by a biofilm-like structure, no viral synapse formation was observed. After infection to SGECs derived from SS patients, adhesion molecules and migration factors were time-dependently released from infected SGECs. The frequency of the appearance of autoantibodies including anti-Ro/SS-A, La/SS-B antibodies in SS patients complicated with HAM is unknown; the observation of less frequent ectopic germinal center formation in HTLV-1-seropositive SS patients was a breakthrough. In addition, HTLV-1 infected cells inhibited B-lymphocyte activating factor or C-X-C motif chemokine 13 through direct contact with established follicular dendritic cell-like cells. These findings show that HTLV-1 is directly involved in the pathogenesis of SS.
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Affiliation(s)
- Hideki Nakamura
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
- Correspondence: ; Tel.: +81-3-3972-8111 (ext. 2400); Fax: +81-3-3972-2893
| | - Masako Tsukamoto
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
| | - Yosuke Nagasawa
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
| | - Noboru Kitamura
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
| | - Toshimasa Shimizu
- Division of Advanced Preventive Medical Sciences, Department of Immunology and Rheumatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan; (T.S.); (A.K.)
| | - Atsushi Kawakami
- Division of Advanced Preventive Medical Sciences, Department of Immunology and Rheumatology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8501, Japan; (T.S.); (A.K.)
| | - Kinya Nagata
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
| | - Masami Takei
- Division of Hematology and Rheumatology, Department of Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan; (M.T.); (Y.N.); (N.K.); (K.N.); (M.T.)
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10
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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11
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Londhe R, Kulkarni S. HTLV-2 Encoded Antisense Protein APH-2 Suppresses HIV-1 Replication. Viruses 2021; 13:v13081432. [PMID: 34452297 PMCID: PMC8402832 DOI: 10.3390/v13081432] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/12/2021] [Accepted: 07/14/2021] [Indexed: 01/31/2023] Open
Abstract
Antisense protein of Human T-cell Leukemia Virus Type 2 (HTLV-2), also called APH-2, negatively regulates the HTLV-2 and helps the virus to maintain latency via scheming the transcription. Despite the remarkable occurrence of HTLV-2/HIV-1 co-infection, the role of APH-2 influencing HIV-1 replication kinetics is poorly understood and needs investigation. In this study, we investigated the plausible role of APH-2 regulating HIV-1 replication. Herein, we report that the overexpression of APH-2 not only hampered the release of HIV-1 pNL4.3 from 293T cells in a dose-dependent manner but also affected the cellular gag expression. A similar and consistent effect of APH-2 overexpression was also observed in case of HIV-1 gag expression vector HXB2 pGag-EGFP. APH-2 overexpression also inhibited the ability of HIV-1 Tat to transactivate the HIV-1 LTR-driven expression of luciferase. Furthermore, the introduction of mutations in the IXXLL motif at the N-terminal domain of APH-2 reverted the inhibitory effect on HIV-1 Tat-mediated transcription, suggesting the possible role of this motif towards the downregulation of Tat-mediated transactivation. Overall, these findings indicate that the HTLV-2 APH-2 may affect the HIV-1 replication at multiple levels by (a) inhibiting the Tat-mediated transactivation and (b) hampering the virus release by affecting the cellular gag expression.
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Affiliation(s)
- Rajkumar Londhe
- Division of Virology, ICMR-National AIDS Research Institute, Pune 411026, Maharashtra, India;
- Savitribai Phule Pune University, Pune 411007, Maharashtra, India
| | - Smita Kulkarni
- Division of Virology, ICMR-National AIDS Research Institute, Pune 411026, Maharashtra, India;
- Savitribai Phule Pune University, Pune 411007, Maharashtra, India
- Correspondence:
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12
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Jaguva Vasudevan AA, Becker D, Luedde T, Gohlke H, Münk C. Foamy Viruses, Bet, and APOBEC3 Restriction. Viruses 2021; 13:504. [PMID: 33803830 PMCID: PMC8003144 DOI: 10.3390/v13030504] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/10/2021] [Accepted: 03/16/2021] [Indexed: 01/24/2023] Open
Abstract
Non-human primates (NHP) are an important source of viruses that can spillover to humans and, after adaptation, spread through the host population. Whereas HIV-1 and HTLV-1 emerged as retroviral pathogens in humans, a unique class of retroviruses called foamy viruses (FV) with zoonotic potential are occasionally detected in bushmeat hunters or zookeepers. Various FVs are endemic in numerous mammalian natural hosts, such as primates, felines, bovines, and equines, and other animals, but not in humans. They are apathogenic, and significant differences exist between the viral life cycles of FV and other retroviruses. Importantly, FVs replicate in the presence of many well-defined retroviral restriction factors such as TRIM5α, BST2 (Tetherin), MX2, and APOBEC3 (A3). While the interaction of A3s with HIV-1 is well studied, the escape mechanisms of FVs from restriction by A3 is much less explored. Here we review the current knowledge of FV biology, host restriction factors, and FV-host interactions with an emphasis on the consequences of FV regulatory protein Bet binding to A3s and outline crucial open questions for future studies.
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Affiliation(s)
- Ananda Ayyappan Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Daniel Becker
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (D.B.); (H.G.)
| | - Tom Luedde
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (D.B.); (H.G.)
- John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre & Institute of Biological Information Processing (IBI-7: Structural Biochemistry), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany;
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13
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Akkouche A, Moodad S, Hleihel R, Skayneh H, Chambeyron S, El Hajj H, Bazarbachi A. In vivo antagonistic role of the Human T-Cell Leukemia Virus Type 1 regulatory proteins Tax and HBZ. PLoS Pathog 2021; 17:e1009219. [PMID: 33471856 PMCID: PMC7817025 DOI: 10.1371/journal.ppat.1009219] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/04/2020] [Indexed: 12/30/2022] Open
Abstract
Adult T cell leukemia (ATL) is an aggressive malignancy secondary to chronic infection by the human T-cell leukemia virus type 1 (HTLV-1) infection. Two viral proteins, Tax and HBZ, play central roles in ATL leukemogenesis. Tax expression transforms T cells in vitro and induces ATL-like disease in mice. Tax also induces a rough eye phenotype and increases hemocyte count in Drosophila melanogaster, indicative of transformation. Among multiple functions, Tax modulates the expression of the enhancer of zeste homolog 2 (EZH2), a methyltransferase of the Polycomb Repressive Complex 2 (PRC2), leading to H3K27me3-dependent reprogramming of around half of cellular genes. HBZ is a negative regulator of Tax-mediated viral transcription. HBZ effects on epigenetic signatures are underexplored. Here, we established an hbz transgenic fly model, and demonstrated that, unlike Tax, which induces NF-κB activation and enhanced PRC2 activity creating an activation loop, HBZ neither induces transformation nor NF-κB activation in vivo. However, overexpression of Tax or HBZ increases the PRC2 activity and both proteins directly interact with PRC2 complex core components. Importantly, overexpression of HBZ in tax transgenic flies prevents Tax-induced NF-κB or PRC2 activation and totally rescues Tax-induced transformation and senescence. Our results establish the in vivo antagonistic effect of HBZ on Tax-induced transformation and cellular effects. This study helps understanding long-term HTLV-1 persistence and cellular transformation and opens perspectives for new therapeutic strategies targeting the epigenetic machinery in ATL. Adult T cell leukemia-lymphoma is an aggressive hematological malignancy, caused by the retroviral infection with HTLV-1. Tax and HBZ play critical roles in leukemia development. Tax activates the NF-κB pathway and modulates the epigenetic machinery to induce cellular proliferation and malignant transformation. We generated hbz or tax/hbz transgenic fly models and explored the phenotypes and epigenetic changes in vivo. Unlike Tax, HBZ expression failed to activate NF-κB or to induce transformation or senescence in vivo, yet activated PRC2 core components resulting in subsequent epigenetic changes. HBZ expression in tax Tg flies inhibits Tax-induced NF-κB or PRC2 activation, resulting in inhibition of malignant cellular proliferation and its consequent senescence. Our study proves the antagonistic effect of HBZ on Tax-induced transformation in vivo, providing further understanding on ATL pathogenesis.
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Affiliation(s)
- Abdou Akkouche
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut, Lebanon
| | - Sara Moodad
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut, Lebanon
| | - Rita Hleihel
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, 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, American University of Beirut, Beirut, Lebanon
| | - Séverine Chambeyron
- Institute of Human Genetics, CNRS, UMR 9002, Montpellier University, Montpellier, France
| | - Hiba El Hajj
- Department of Experimental Pathology, Immunology and Microbiology, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- * E-mail: (HEH); (AB)
| | - Ali Bazarbachi
- Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut, Lebanon
- * E-mail: (HEH); (AB)
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14
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Zhang Z, Perković M, Gu Q, Balakrishnan K, Sangwiman A, Häussinger D, Lindemann D, Münk C. HIV-2 Vif and foamy virus Bet antagonize APOBEC3B by different mechanisms. Virology 2020; 554:17-27. [PMID: 33333348 DOI: 10.1016/j.virol.2020.11.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 11/13/2020] [Accepted: 11/17/2020] [Indexed: 11/17/2022]
Abstract
The family of human APOBEC3 (A3) restriction factors is formed by seven different proteins, A3A-D and A3F-H. Among these A3s, A3B harbors strong restriction activity against several retroviruses, such as SIV, and MLV. How lentiviruses and other retroviruses, prevalent in many primate species, counteract A3B is poorly understood. In this study, we found that A3B strongly inhibited SIVmac and HIV-2 infectivity, which was antagonized by their Vif proteins. Both SIVmac and HIV-2 Vifs diminished the protein level of A3B in viral producer cells, and hindered A3B incorporation into viral particles. We observed that HIV-2 Vif binds A3B and induces its degradation by assembly of an A3-Vif-CUL5-ElonginB/C E3-ligase complex. A3B and HIV-2 Vif localize and interact in the nucleus. In addition, we also found that the accessory protein Bet of prototype foamy virus (PFV) significantly antagonized the anti-SIVmac activity of A3B. Like Vif, Bet prevented the incorporation of A3B into viral particles. However, in contrast to Vif Bet did not induce the degradation of A3B. Rather, Bet binds A3B to block formation of high molecular weight A3B complexes and induces A3B cytoplasmic trapping. In summary, these findings indicate that A3B is recognized by diverse retroviruses and counteracted by virus-specific pathways that could be targeted to inhibit A3B mutating activity in cancers.
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Affiliation(s)
- Zeli Zhang
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Mario Perković
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Qinyong Gu
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Kannan Balakrishnan
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Anucha Sangwiman
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Dirk Lindemann
- Institute of Virology, Medical Faculty "Carl Gustav Carus", Technische Universität Dresden, 01307, Dresden, Germany; CRTD/DFG-Center for Regenerative Therapies, Technische Universität Dresden, 01307, Dresden, Germany
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
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15
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Abstract
The unique structural flexibility of intrinsically disordered proteins (IDPs) is central to their diverse functions in cellular processes. Protein-protein interactions involving IDPs are frequently transient and dynamic in nature. Nuclear magnetic resonance (NMR) spectroscopy is an especially powerful tool for characterizing the structural propensities, dynamics, and interactions of IDPs. Here we describe applications of the Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiment in combination with NMR titrations to characterize the kinetics and mechanisms of interactions between intrinsically disordered proteins and their targets. We illustrate the method with reference to interactions between the activation domain of the human T-cell leukemia virus type-I (HTLV-1) basic leucine zipper protein (HBZ) and its cellular binding partner, the KIX domain of the transcriptional coactivator CBP.
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Affiliation(s)
- Ke Yang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Munehito Arai
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
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16
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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] [What about the content of this article? (0)] [Affiliation(s)] [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.
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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)
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17
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Mozhgani SH, Jahantigh HR, Rafatpanah H, Valizadeh N, Mohammadi A, Basharkhah S, Rezaee SA. Interferon Lambda Family along with HTLV-1 Proviral Load, Tax, and HBZ Implicated in the Pathogenesis of Myelopathy/Tropical Spastic Paraparesis. NEURODEGENER DIS 2018; 18:150-155. [PMID: 29990995 DOI: 10.1159/000490058] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 05/08/2018] [Indexed: 11/19/2022] Open
Abstract
HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic neuroinflammatory disease related to human T lymphotropic virus type 1 (HTLV-1) infection. Interferon type III (IFN-λ), which includes IL28, IL29, and IL28R, and affects the outcome of viral infections, might be complicated in the progression of HAM/TSP. Here, we investigated the host-virus interactions in the manifestation of HAM/TSP, using IL28B, IL29, IL28R, HTLV-1 Tax, HTLV-1 basic leucine zipper factor (HBZ), and proviral load (PVL). The study groups consisted of 20 patients with HAM/TSP, 20 asymptomatic HTLV-1 carriers (ACs), and 20 healthy controls (HCs). The means of PVL, Tax, and HBZ gene expressions in the HAM/TSP group (p = 0.004, 0.006, and < 0.0001, respectively) were significantly higher than in the AC group. The comparison of IL28B, IL29, and IL28R expression in the HAM/TSP, AC, and HC groups revealed no significant difference between the first 2, but lower concentrations in the HCs (IL28B: p = 0.03, 0.01; IL29: p = 0.07, 0.01; and IL28R: p < 0.0001, respectively). In the HAM/TSP group, correlations were seen between Tax and HBZ (R = 0.61, p = 0.004) and between Tax and IL29 (R = 0.45, p = 0.04). Negative correlations were observed between Tax and IL28B (R = -0.49, p = 0.02) and between HBZ and IL28R (R = -0.43, p = 0.06). In the ACs, an inverse correlation was found between Tax and IL28B (R = -0.42, p = 0.06). These findings suggest that IL29, IL28B, and IL28R interfere in the infection of HAM/TSP, mainly via Tax activation.
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Affiliation(s)
- Sayed-Hamidreza Mozhgani
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
- Department of Microbiology, School of Medicine, Alborz University of Medical Sciences, Karaj, Iran
| | - Hamid Reza Jahantigh
- Immunology Research Center, Inflammation and Inflammatory Diseases Division, Mashhad University of Medical Sciences, Mashhad, Iran
- Student Research Committee, Faculty of Medicine, Mashhad University of Medical Science, Mashhad, Iran
| | - Houshang Rafatpanah
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Narges Valizadeh
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Asadollah Mohammadi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Samira Basharkhah
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Seyed Abdolrahim Rezaee
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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18
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Hutchison T, Malu A, Yapindi L, Bergeson R, Peck K, Romeo M, Harrod C, Pope J, Smitherman L, Gwinn W, Ratner L, Yates C, Harrod R. The TP53-Induced Glycolysis and Apoptosis Regulator mediates cooperation between HTLV-1 p30 II and the retroviral oncoproteins Tax and HBZ and is highly expressed in an in vivo xenograft model of HTLV-1-induced lymphoma. Virology 2018; 520:39-58. [PMID: 29777913 DOI: 10.1016/j.virol.2018.05.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/08/2018] [Accepted: 05/10/2018] [Indexed: 12/28/2022]
Abstract
The human T-cell leukemia virus type-1 (HTLV-1) is an oncoretrovirus that infects and transforms CD4+ T-cells and causes adult T-cell leukemia/lymphoma (ATLL) -an aggressive lymphoproliferative disease that is highly refractive to most anticancer therapies. The HTLV-1 proviral genome encodes several regulatory products within a conserved 3' nucleotide sequence, known as pX; however, it remains unclear how these factors might cooperate or dynamically interact in virus-infected cells. Here we demonstrate that the HTLV-1 latency-maintenance factor p30II induces the TP53-induced glycolysis and apoptosis regulator (TIGAR) and counters the oxidative stress, mitochondrial damage, and cytotoxicity caused by the viral oncoproteins Tax and HBZ. The p30II protein cooperates with Tax and HBZ and enhances their oncogenic potential in colony transformation/foci-formation assays. Further, we have shown that TIGAR is highly expressed in HTLV-1-induced tumors associated with oncogene dysregulation and increased angiogenesis in an in vivo xenograft model of HTLV-1-induced T-cell lymphoma. These findings provide the first evidence that p30II likely collaborates as an ancillary factor for the major oncoproteins Tax and HBZ during retroviral carcinogenesis.
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Affiliation(s)
- Tetiana Hutchison
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Aditi Malu
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Laçin Yapindi
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Rachel Bergeson
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Kendra Peck
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Megan Romeo
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Carolyn Harrod
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Jordan Pope
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Louisa Smitherman
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Wesleigh Gwinn
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States
| | - Lee Ratner
- Departments of Medicine and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, United States
| | - Courtney Yates
- Laboratory Animal Resource Center, Southern Methodist University, Dallas, TX 75275, United States
| | - Robert Harrod
- Laboratory of Molecular Virology, Department of Biological Sciences, and The Dedman College Center for Drug Discovery, Design & Delivery, Southern Methodist University, 6501 Airline Drive, 334-DLS, Dallas, TX 75275-0376, United States.
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19
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Nakamura H, Hasegawa H, Sasaki D, Takatani A, Shimizu T, Kurushima S, Horai Y, Nakashima Y, Nakamura T, Fukuoka J, Kawakami A. Detection of human T lymphotropic virus type-I bZIP factor and tax in the salivary glands of Sjögren's syndrome patients. Clin Exp Rheumatol 2018; 36 Suppl 112:51-60. [PMID: 29600938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 02/12/2018] [Indexed: 06/08/2023]
Abstract
OBJECTIVES To detect HTLV-I bZIP factor (HBZ), tax and relevant molecules in labial salivary glands (LSGs) from patients with Sjögren's syndrome (SS). METHODS The expressions of HBZ and tax in T cell lines and LSGs were analysed by in situ hybridization (ISH) or real time PCR. The expressions of forkhead box P3 (Foxp3) and p65 in immunohistochemistry were quantified. RESULTS After specificity of ISH probes was determined in 5 T cell lines, in LSGs from an adult T-cell leukemia (ATL) patient and 3 HTLV-I-associated myelopathy (HAM)-SS patients, both HBZ and tax signals were detected in infiltrating mononuclear cells (MNCs) and ducts, and HBZ and tax were dominantly expressed in MNCs of ATL and HAM-SS, respectively. HBZ was dominantly observed in LSGs from 8 HTLV-I asymptomatic carrier (AC)-SS patients; faint expression of HBZ was observed in LSGs from 5 HTLV-I-seronegative SS patients. No cell adhesion molecule 1(CADM1) expressed in LSGs from the ATL patient. Although Foxp3 expression was observed in LSG MNCs of all of the SS patients, the ATL patient's expression was significantly greater than that of the AC-SS (p<0.01) and HTLV-I-seronegative SS (p<0.01) patients. The Foxp3 expression was similar in ATL and HAMSS, but significantly higher in HAM-SS than AC-SS (p<0.05). p65 was expressed in LSG MNC nuclei from all SS patients and co-expressed with Foxp3. The expressions of Foxp3 in ducts differed according to HTLV-I infection. CONCLUSIONS These results suggest that HBZ-mediated Foxp3 expression is partly associated with the pathogenesis of HTLV-I-seropositive SS.
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Affiliation(s)
- Hideki Nakamura
- Department of Immunology and Rheumatology, Unit of Advanced Medical Sciences, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan.
| | - Hiroo Hasegawa
- Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Daisuke Sasaki
- Department of Laboratory Medicine, Nagasaki University Hospital, Nagasaki, Japan
| | - Ayuko Takatani
- Department of Immunology and Rheumatology, Unit of Advanced Medical Sciences, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Toshimasa Shimizu
- Department of Immunology and Rheumatology, Unit of Advanced Medical Sciences, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Shota Kurushima
- Department of Immunology and Rheumatology, Unit of Advanced Medical Sciences, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Yoshiro Horai
- Clinical Research Centre, National Hospital Organization Nagasaki Medical Centre, Nagasaki, Japan
| | - Yoshikazu Nakashima
- Department of Immunology and Rheumatology, Sasebo City General Hospital, Nagasaki, Japan
| | - Tatsufumi Nakamura
- Department of Social Work, Faculty of Human and Social Studies, Nagasaki International University, Nagasaki, Japan
| | - Junya Fukuoka
- Department of Pathology, Nagasaki University Hospital, Nagasaki, Japan
| | - Atsushi Kawakami
- Department of Immunology and Rheumatology, Unit of Advanced Medical Sciences, Division of Advanced Preventive Medical Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
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20
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Abstract
Post-translational modifications (PTMs) are chemical alterations to individual amino acids that alter a protein's conformation, stability, and/or function. Several pathogenic viruses have been shown to encode proteins with PTMs, including human T-cell leukemia virus type 1 (HTLV-1) Tax and Rex regulatory proteins. HTLV-1 basic leucine zipper protein (HBZ) was hypothesized to feature PTMs due to its functional activities and interactions with cellular transcription factors and acetyltransferases. Here, we describe the approach used to identify, via mass spectrometry, the PTMs of HBZ. In addition, we describe methods to determine the functional relevance of the identified PTMs.
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Affiliation(s)
- Jacob Al-Saleem
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, 43210, USA
| | - Mamuka Kvaratskhelia
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA
- College of Pharmacy, The Ohio State University, Columbus, OH, 43210, USA
| | - Patrick L Green
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, 43210, USA.
- Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, 43210, USA.
- Compreshensive Cancer Center and Solove Research Institute, The Ohio State University, Columbus, OH, 43210, USA.
- Department of Molecular Virology, Immunology, and Medical Genetics, The Ohio State University, 127N Veterinary Medicine Academic Building, 1900 Coffey Rd, Columbus, OH, 43210, USA.
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21
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Giam CZ, Semmes OJ. HTLV-1 Infection and Adult T-Cell Leukemia/Lymphoma-A Tale of Two Proteins: Tax and HBZ. Viruses 2016; 8:v8060161. [PMID: 27322308 PMCID: PMC4926181 DOI: 10.3390/v8060161] [Citation(s) in RCA: 99] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/31/2016] [Accepted: 06/01/2016] [Indexed: 12/19/2022] Open
Abstract
HTLV-1 (Human T-cell lymphotropic virus type 1) is a complex human delta retrovirus that currently infects 10–20 million people worldwide. While HTLV-1 infection is generally asymptomatic, 3%–5% of infected individuals develop a highly malignant and intractable T-cell neoplasm known as adult T-cell leukemia/lymphoma (ATL) decades after infection. How HTLV-1 infection progresses to ATL is not well understood. Two viral regulatory proteins, Tax and HTLV-1 basic zipper protein (HBZ), encoded by the sense and antisense viral transcripts, respectively, are thought to play indispensable roles in the oncogenic process of ATL. This review focuses on the roles of Tax and HBZ in viral replication, persistence, and oncogenesis. Special emphasis is directed towards recent literature on the mechanisms of action of these two proteins and the roles of Tax and HBZ in influencing the outcomes of HTLV-1 infection including senescence induction, viral latency and persistence, genome instability, cell proliferation, and ATL development. Attempts are made to integrate results from cell-based studies of HTLV-1 infection and studies of HTLV-1 proviral integration site preference, clonality, and clonal expansion based on high throughput DNA sequencing. Recent data showing that Tax hijacks key mediators of DNA double-strand break repair signaling—the ubiquitin E3 ligase, ring finger protein 8 (RNF8) and the ubiquitin E2 conjugating enzyme (UBC13)—to activate the canonical nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) and other signaling pathways will be discussed. A perspective on how the Tax-RNF8 signaling axis might impact genomic instability and how Tax may collaborate with HBZ to drive oncogenesis is provided.
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Affiliation(s)
- Chou-Zen Giam
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
| | - Oliver John Semmes
- Department of Microbiology and Molecular Cell Biology, The Leroy T. Canoles Jr Cancer Research Center, Eastern Virginia Medical School, Norfolk, VA 23501, USA.
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22
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Wu W, Cheng W, Chen M, Xu L, Zhao T. [HTLV-1 bZIP Factor (HBZ): Roles in HTLV-1 Oncogenesis]. Bing Du Xue Bao 2016; 32:235-242. [PMID: 27396170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus demonstrated to be associated with human disease. Infection by the HTLV-1 can cause T-cell leukemia (ATL) in adults. HTLV-1 bZIP factor (HBZ) is a viral protein encoded by the minus strand of the HTLV-1 provirus. Among the regulatory and accessory genes of HTLV-1, HBZ is the only gene that remains intact and which is expressed consistently in all patients with ATL. Moreover, HBZ has a critical role in the leukemogenesis of ATL. Here, we review the function of HBZ in the oncogenesis of HTLV-1 and its molecular mechanism of action.
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23
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Abstract
Human T-cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL) and chronic inflammatory diseases. HTLV-1 bZIP factor (HBZ) is transcribed as an antisense transcript of the HTLV-1 provirus. Among the HTLV-1-encoded viral genes, HBZ is the only gene that is constitutively expressed in all ATL cases. Recent studies have demonstrated that HBZ plays an essential role in oncogenesis by regulating viral transcription and modulating multiple host factors, as well as cellular signaling pathways, that contribute to the development and continued growth of cancer. In this article, I summarize the current knowledge of the oncogenic function of HBZ in cell proliferation, apoptosis, T-cell differentiation, immune escape, and HTLV-1 pathogenesis.
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Affiliation(s)
- Tiejun Zhao
- College of Chemistry and Life Sciences, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, China.
- Key Lab of Wildlife Biotechnology and Conservation and Utilization of Zhejiang Province, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, China.
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24
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Abstract
Despite the inability of HIV-1 to infect neurons, over half of the HIV-1-infected population in the USA suffers from neurocognitive dysfunction. HIV-infected immune cells in the periphery enter the central nervous system by causing a breach in the blood-brain barrier. The damage to the neurons is mediated by viral and host toxic products released by activated and infected immune and glial cells. To evaluate the toxicity of any viral isolate, viral protein, or host inflammatory protein, we describe a protocol to assess the neuronal apoptosis and synaptic compromise in primary cultures of human neurons and astrocytes.
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Affiliation(s)
- Vasudev R Rao
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, 10461, USA
| | - Eliseo A Eugenin
- Public Health Research Institute (PHRI), Rutgers The State University of New Jersey, Newark, NJ, USA
- Department of Microbiology and Molecular Genetics, Rutgers The State University of New Jersey, Newark, NJ, USA
| | - Vinayaka R Prasad
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY, 10461, USA.
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25
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Skalka AM(A, Andrake MD, Katz RA. Successes and challenges with retroviral enzymes. Postepy Biochem 2016; 62:280-285. [PMID: 28132482 PMCID: PMC6177231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
Collaborations between the Wlodawer and Skalka laboratories have covered a period of almost 30 years. During that time our groups have co-authored 18 publications, including several much cited journal articles, book chapters, and scholarly reviews. It has therefore been most rewarding for us to share enthusiasm, insights, and expertise with our Frederick colleagues over the years, and also to enjoy lasting friendships.
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Affiliation(s)
- Anna Marie (Ann) Skalka
- Fox Chase Cancer Center, Institute for Cancer Research, Temple University Health System, Philadelphia PA, USA.
| | - Mark D. Andrake
- Fox Chase Cancer Center, Institute for Cancer Research, Temple University Health System, Philadelphia PA, USA.
| | - Richard A. Katz
- Fox Chase Cancer Center, Institute for Cancer Research, Temple University Health System, Philadelphia PA, USA.
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26
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Zheng L, Du Z, Lin C, Mao Q, Wu K, Wu J, Wei T, Wu Z, Xie L. Rice stripe tenuivirus p2 may recruit or manipulate nucleolar functions through an interaction with fibrillarin to promote virus systemic movement. Mol Plant Pathol 2015; 16:921-30. [PMID: 25431002 PMCID: PMC6638460 DOI: 10.1111/mpp.12220] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Rice stripe virus (RSV) is the type species of the genus Tenuivirus and represents a major viral pathogen affecting rice production in East Asia. In this study, RSV p2 was fused to yellow fluorescent protein (p2-YFP) and expressed in epidermal cells of Nicotiana benthamiana. p2-YFP fluorescence was found to move to the nucleolus initially, but to leave the nucleolus for the cytoplasm forming numerous distinct bright spots there at later time points. A bimolecular fluorescence complementation (BiFC) assay showed that p2 interacted with fibrillarin and that the interaction occurred in the nucleus. Both the nucleolar localization and cytoplasmic distribution of p2-YFP fluorescence were affected in fibrillarin-silenced N. benthamiana. Fibrillarin depletion abolished the systemic movement of RSV, but not that of Tobacco mosaic virus (TMV) and Potato virus X (PVX). A Tobacco rattle virus (TRV)-based virus-induced gene silencing (VIGS) method was used to diminish RSV NS2 (encoding p2) or NS3 (encoding p3) during RSV infection. Silencing of NS3 alleviated symptom severity and reduced RSV accumulation, but had no obvious effects on virus movement and the timing of symptom development. However, silencing of NS2 abolished the systemic movement of RSV. The possibility that RSV p2 may recruit or manipulate nucleolar functions to promote virus systemic infection is discussed.
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Affiliation(s)
- Luping Zheng
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenguo Du
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, GAAS, Guangzhou, 510640, China
| | - Chen Lin
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Bayuquan Entry-Exit Inspection and Quarantine Bureau, Yingkou, 115007, China
| | - Qianzhuo Mao
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Kangcheng Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianguo Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Taiyun Wei
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zujian Wu
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Lianhui Xie
- Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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27
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Boostani R, Vakili R, Hosseiny SS, Shoeibi A, Fazeli B, Etemadi MM, Sabet F, Valizade N, Rezaee SA. Triple Therapy with Prednisolone, Pegylated Interferon and Sodium Valproate Improves Clinical Outcome and Reduces Human T-Cell Leukemia Virus Type 1 (HTLV-1) Proviral Load, Tax and HBZ mRNA Expression in Patients with HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis. Neurotherapeutics 2015; 12:887-95. [PMID: 26174324 PMCID: PMC4604181 DOI: 10.1007/s13311-015-0369-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Considering that there is no effective treatment for human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis, this study aimed to assess the impact of triple combination therapy-interferon-α, valproic acid, and prednisolone-on clinical outcomes, main HTLV-1 viral factors, and host anti-HTLV-1 antibody response. HTLV-1 proviral load (PVL), and HBZ and Tax mRNA expression levels were measured in peripheral blood mononuclear cells of 13 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis before and after treatment with 180 μg pegylated interferon once a week, 10-20 mg/kg/day sodium valproate, and 5 mg/day prednisolone for 25 weeks using a TaqMan real-time polymerase chain reaction assay. Furthermore, anti-HTLV-1 titer, Osame Motor Disability Score, Ashworth spasticity scale, and urinary symptoms (through standard questionnaire and clinical monitoring) were assessed in patients before and after the treatment. HTLV-1 PVL and HBZ expression significantly decreased after the treatment [PVL from 1443 ± 282 to 660 ± 137 copies/10(4) peripheral blood mononuclear cells (p = 0.01); and HBZ from 8.0 ± 1.5 to 3.0 ± 0.66 (p < 0.01)]. Tax mRNA expression decreased after the treatment from 2.26 ± 0.45 to 1.44 ± 0.64, but this reduction was not statistically significant (p = 0.10). Furthermore, anti-HTLV-1 titer reduced dramatically after the treatment, from 3123 ± 395 to 815 ± 239 (p < 0.01). Clinical signs and symptoms, according to Osame Motor Disability Score and Ashworth score, improved significantly (both p < 0.01). Urinary symptoms and sensory disturbances with lower back pain were reduced, though not to a statistically significant degree. Although signs and symptoms of spasticity were improved, frequent urination and urinary incontinence were not significantly affected by the triple therapy. The results provide new insight into the complicated conditions underlying HTLV-1-associated diseases.
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Affiliation(s)
- Reza Boostani
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Rosita Vakili
- Center of Pathological and Medical Diagnostic Services, Iranian Academic Center for Education, Culture & Research (ACECR), Mashhad Branch, Mashhad, Iran
| | - Samane Sadat Hosseiny
- Department of Biology, Science and Research Branch, Islamic Azad University, Kurdistan, Iran
| | - Ali Shoeibi
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Bahare Fazeli
- Inflammation and Inflammatory Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohammad Mehdi Etemadi
- Department of Neurology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | - Narges Valizade
- Inflammation and Inflammatory Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Seyed Abdolrahim Rezaee
- Inflammation and Inflammatory Diseases Research Center, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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28
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Han B, Shi XL, Zhang Y, Gu ZZ, Yuan XW, Ren HZ, Qiu Y, Ding YT. No transmission of porcine endogenous retrovirus in an acute liver failure model treated by a novel hybrid bioartificial liver containing porcine hepatocytes. Hepatobiliary Pancreat Dis Int 2015; 14:492-501. [PMID: 26459725 DOI: 10.1016/s1499-3872(15)60401-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND A novel hybrid bioartificial liver (HBAL) was constructed using an anionic resin adsorption column and a multi-layer flat-plate bioreactor containing porcine hepatocytes co-cultured with bone marrow mesenchymal stem cells (MSCs). This study aimed to evaluate the microbiological safety of the HBAL by detecting the transmission of porcine endogenous retroviruses (PERVs) into canines with acute liver failure (ALF) undergoing HBAL. METHODS Eight dogs with ALF received a 6-hour HBAL treatment on the first day after the modeling by D-galactosamine administration. The plasma in the HBAL and the whole blood in the dogs were collected for PERV detection at regular intervals until one year later when the dogs were sacrificed to retrieve the tissues of several organs for immunohistochemistry and Western blotting for the investigation of PERV capsid protein gag p30 in the tissue. Furthermore, HEK293 cells were incubated to determine the in vitro infectivity. RESULTS PERV RNA and reverse transcriptase activity were observed in the plasma of circuit 3, suggesting that PERV particles released in circuit 3. No positive PERV RNA and reverse transcriptase activity were detected in other plasma. No HEK293 cells were infected by the plasma in vitro. In addition, all PERV-related analyses in peripheral blood mononuclear cells and tissues were negative. CONCLUSION No transmission of PERVs into ALF canines suggested a reliable microbiological safety of HBAL based on porcine hepatocytes.
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Affiliation(s)
- Bing Han
- Department of Hepatobiliary Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008, China.
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29
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Postler TS, Bixby JG, Desrosiers RC, Yuste E. Systematic analysis of intracellular trafficking motifs located within the cytoplasmic domain of simian immunodeficiency virus glycoprotein gp41. PLoS One 2014; 9:e114753. [PMID: 25479017 PMCID: PMC4257708 DOI: 10.1371/journal.pone.0114753] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/13/2014] [Indexed: 12/19/2022] Open
Abstract
Previous studies have shown that truncation of the cytoplasmic-domain sequences of the simian immunodeficiency virus (SIV) envelope glycoprotein (Env) just prior to a potential intracellular-trafficking signal of the sequence YIHF can strongly increase Env protein expression on the cell surface, Env incorporation into virions and, at least in some contexts, virion infectivity. Here, all 12 potential intracellular-trafficking motifs (YXXΦ or LL/LI/IL) in the gp41 cytoplasmic domain (gp41CD) of SIVmac239 were analyzed by systematic mutagenesis. One single and 7 sequential combination mutants in this cytoplasmic domain were characterized. Cell-surface levels of Env were not significantly affected by any of the mutations. Most combination mutations resulted in moderate 3- to 8-fold increases in Env incorporation into virions. However, mutation of all 12 potential sites actually decreased Env incorporation into virions. Variant forms with 11 or 12 mutated sites exhibited 3-fold lower levels of inherent infectivity, while none of the other single or combination mutations that were studied significantly affected the inherent infectivity of SIVmac239. These minor effects of mutations in trafficking motifs form a stark contrast to the strong increases in cell-surface expression and Env incorporation which have previously been reported for large truncations of gp41CD. Surprisingly, mutation of potential trafficking motifs in gp41CD of SIVmac316, which differs by only one residue from gp41CD of SIVmac239, effectively recapitulated the increases in Env incorporation into virions observed with gp41CD truncations. Our results indicate that increases in Env surface expression and virion incorporation associated with truncation of SIVmac239 gp41CD are not fully explained by loss of consensus trafficking motifs.
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Affiliation(s)
- Thomas S. Postler
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, United States of America
| | - Jacqueline G. Bixby
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, United States of America
| | - Ronald C. Desrosiers
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, United States of America
| | - Eloísa Yuste
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, United States of America
- * E-mail:
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30
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Ma QL, Yu M, Luo D, Tan J, Qiao WT. [Identification of prototype foamy virus Bel1 nuclear localization signal and its corresponding importins]. Bing Du Xue Bao 2014; 30:346-352. [PMID: 25272585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Bel1, a transactivator of prototype foamy virus (PFV), plays pivotal roles in the replication of PFV. Previous studies have shown that Bel1 bears a nuclear localization signal (NLS), but its amino acid sequence remains unclear and the corresponding importins have not been identified. In this report, we inserted various fragments of Bel1 into an EGFP-GST fusion protein and investigated their subcellular localization by fluorescence microscopy. We found that the 215PRQKRPR221 fragment could direct nuclear localization, which accords with the consensus sequence K(K/R)X(K/R) of monopartite NLS. Point mutation experiments revealed that K218, R219, and R221 are essential for the nuclear localization of Bel1. The results of the GST-pulldown showed that the Bel1 fragment with residues 215-223, which bears the NLS, interacts with KPNA1, KPNA6, and KPNA7. This result suggests that KPNA1, KPNA6, and KPNA7 maybe involved in Bel1 nuclear translocation.
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31
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Esnault C, Cornelis G, Heidmann O, Heidmann T. Differential evolutionary fate of an ancestral primate endogenous retrovirus envelope gene, the EnvV syncytin, captured for a function in placentation. PLoS Genet 2013; 9:e1003400. [PMID: 23555306 PMCID: PMC3610889 DOI: 10.1371/journal.pgen.1003400] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 02/06/2013] [Indexed: 01/25/2023] Open
Abstract
Syncytins are envelope genes of retroviral origin that have been co-opted for a role in placentation. They promote cell–cell fusion and are involved in the formation of a syncytium layer—the syncytiotrophoblast—at the materno-fetal interface. They were captured independently in eutherian mammals, and knockout mice demonstrated that they are absolutely required for placenta formation and embryo survival. Here we provide evidence that these “necessary” genes acquired “by chance” have a definite lifetime with diverse fates depending on the animal lineage, being both gained and lost in the course of evolution. Analysis of a retroviral envelope gene, the envV gene, present in primate genomes and belonging to the endogenous retrovirus type V (ERV-V) provirus, shows that this captured gene, which entered the primate lineage >45 million years ago, behaves as a syncytin in Old World monkeys, but lost its canonical fusogenic activity in other primate lineages, including humans. In the Old World monkeys, we show—by in situ analyses and ex vivo assays—that envV is both specifically expressed at the level of the placental syncytiotrophoblast and fusogenic, and that it further displays signs of purifying selection based on analysis of non-synonymous to synonymous substitution rates. We further show that purifying selection still operates in the primate lineages where the gene is no longer fusogenic, indicating that degeneracy of this ancestral syncytin is a slow, lineage-dependent, and multi-step process, in which the fusogenic activity would be the first canonical property of this retroviral envelope gene to be lost. Syncytins are “new” genes encoding the envelope protein of captured endogenous retroviral elements. Their unambiguous status of “cellular gene” was recently demonstrated by knocking them out in genetically modified mice, showing their absolute requirement for placenta formation and embryo survival, via formation by cell–cell fusion of the feto-maternal syncytium interface. These genes are remarkable, as they are “necessary” for a basic function in placental mammals and yet they were acquired “by chance” on multiple occasions and independently in diverse mammalian species. We proposed that syncytins have been pivotal for the emergence of animals with a placenta from those laying eggs via the capture of a founding retroviral env gene, then subsequently replaced in the diverse mammalian lineages upon successive and independent germline infections by new retroviruses and co-optation of their env gene, each new gene providing its host with a positive selective advantage. This hypothesis would account for the diversity of the captured syncytins that can be currently found, concomitant with the diversity of placental architectures. A consequence of this paradigm is that evidence for “decaying syncytins” in eutherian mammals should exist, and this is precisely what we sought—and found—in this study.
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Affiliation(s)
- Cécile Esnault
- Unité des Rétrovirus Endogènes et Éléments Rétroïdes des Eucaryotes Supérieurs, Unité Mixte de Recherche 8122, Centre National de la Recherche Scientifique, Institut Gustave Roussy, Villejuif, France
- Université Paris-Sud, Orsay, France
| | - Guillaume Cornelis
- Unité des Rétrovirus Endogènes et Éléments Rétroïdes des Eucaryotes Supérieurs, Unité Mixte de Recherche 8122, Centre National de la Recherche Scientifique, Institut Gustave Roussy, Villejuif, France
- Université Paris-Sud, Orsay, France
- Université Paris Diderot, Paris Sorbonne Cité, Paris, France
| | - Odile Heidmann
- Unité des Rétrovirus Endogènes et Éléments Rétroïdes des Eucaryotes Supérieurs, Unité Mixte de Recherche 8122, Centre National de la Recherche Scientifique, Institut Gustave Roussy, Villejuif, France
- Université Paris-Sud, Orsay, France
| | - Thierry Heidmann
- Unité des Rétrovirus Endogènes et Éléments Rétroïdes des Eucaryotes Supérieurs, Unité Mixte de Recherche 8122, Centre National de la Recherche Scientifique, Institut Gustave Roussy, Villejuif, France
- Université Paris-Sud, Orsay, France
- * E-mail:
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Cordeil S, Nguyen XN, Berger G, Durand S, Ainouze M, Cimarelli A. Evidence for a different susceptibility of primate lentiviruses to type I interferons. J Virol 2013; 87:2587-96. [PMID: 23255800 PMCID: PMC3571359 DOI: 10.1128/jvi.02553-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 12/10/2012] [Indexed: 12/11/2022] Open
Abstract
Type I interferons induce a complex transcriptional program that leads to a generalized antiviral response against a large panel of viruses, including human immunodeficiency virus type 1 (HIV-1). However, despite the fact that interferons negatively regulate HIV-1 ex vivo, a chronic interferon state is linked to the progression of AIDS and to robust viral replication, rather than protection, in vivo. To explain this apparent contradiction, we hypothesized that HIV-1 may have evolved a partial resistance to interferon, and to test this hypothesis, we analyzed the effects of alpha interferon (IFN-α) on the infectivity of HIV-1, human immunodeficiency virus type 2 (HIV-2), and rhesus monkey simian immunodeficiency virus (SIVmac). The results we obtained indicate that HIV-1 is more resistant to an IFN-α-induced response than are HIV-2 and SIVmac. Our data indicate that the accumulation of viral DNA is more compromised following the infection of IFN-α-treated cells with HIV-2 and SIVmac than with HIV-1. This defect correlates with a faster destabilization of HIV-2 viral nucleoprotein complexes (VNCs), suggesting a link between VNC destabilization and impaired viral DNA (vDNA) accumulation. The differential susceptibilities to IFN-α of the primate lentiviruses tested here do not map to the capsid protein (CA), excluding de facto a role for human tripartite motif protein isoform 5 alpha (Trim5α) in this restriction; this also suggests that an additional restriction mechanism differentially affects primate lentivirus infection. The different behaviors of HIV-1 and HIV-2 with respect to IFN-α responses may account at least in part for the differences in pathogenesis observed between these two virus types.
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Abstract
Discovering network motifs could provide a significant insight into systems biology. Interestingly, many biological networks have been found to have a high degree of symmetry (automorphism), which is inherent in biological network topologies. The symmetry due to the large number of basic symmetric subgraphs (BSSs) causes a certain redundant calculation in discovering network motifs. Therefore, we compress all basic symmetric subgraphs before extracting compressed subgraphs and propose an efficient decompression algorithm to decompress all compressed subgraphs without loss of any information. In contrast to previous approaches, the novel Symmetry Compression method for Motif Detection, named as SCMD, eliminates most redundant calculations caused by widespread symmetry of biological networks. We use SCMD to improve three notable exact algorithms and two efficient sampling algorithms. Results of all exact algorithms with SCMD are the same as those of the original algorithms, since SCMD is a lossless method. The sampling results show that the use of SCMD almost does not affect the quality of sampling results. For highly symmetric networks, we find that SCMD used in both exact and sampling algorithms can help get a remarkable speedup. Furthermore, SCMD enables us to find larger motifs in biological networks with notable symmetry than previously possible.
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Affiliation(s)
- Jianxin Wang
- School of Information Engineering and Science, Central South University, Computer Building, Changsha, Hunan, P.R. China.
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Padilla-Parra S, Marin M, Kondo N, Melikyan GB. Synchronized retrovirus fusion in cells expressing alternative receptor isoforms releases the viral core into distinct sub-cellular compartments. PLoS Pathog 2012; 8:e1002694. [PMID: 22589725 PMCID: PMC3349758 DOI: 10.1371/journal.ppat.1002694] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/27/2012] [Indexed: 12/02/2022] Open
Abstract
Disparate enveloped viruses initiate infection by fusing with endosomes. However, the highly diverse and dynamic nature of endosomes impairs mechanistic studies of fusion and identification of sub-cellular sites supporting the nucleocapsid release. We took advantage of the extreme stability of avian retrovirus-receptor complexes at neutral pH and of acid-dependence of virus-endosome fusion to isolate the latter step from preceding asynchronous internalization/trafficking steps. Viruses were trapped within endosomes in the presence of NH4Cl. Removal of NH4Cl resulted in a quick and uniform acidification of all subcellular compartments, thereby initiating synchronous viral fusion. Single virus imaging demonstrated that fusion was initiated within seconds after acidification and often culminated in the release of the viral core from an endosome. Comparative studies of cells expressing either the transmembrane or GPI-anchored receptor isoform revealed that the transmembrane receptor delivered the virus to more fusion-permissive compartments. Thus the identity of endosomal compartments, in addition to their acidity, appears to modulate viral fusion. A more striking manifestation of the virus delivery to distinct compartments in the presence of NH4Cl was the viral core release into the cytosol of cells expressing the transmembrane receptor and into endosomes of cells expressing the GPI-anchored isoform. In the latter cells, the newly released cores exhibited restricted mobility and were exposed to a more acidic environment than the cytoplasm. These cores appear to enter into the cytosol after an additional slow temperature-dependent step. We conclude that the NH4Cl block traps the virus within intralumenal vesicles of late endosomes in cells expressing the GPI-anchored receptor. Viruses surrounded by more than one endosomal membrane release their core into the cytoplasm in two steps – fusion with an intralumenal vesicle followed by a yet unknown temperature-dependent step that liberates the core from late endosomes. Endosomal trafficking and regulation of retrovirus fusion is poorly understood, due in part to heterogeneity of viral particles and their asynchronous entry into an endocytic pathway. Here, we used an avian retrovirus that enters host cells in a receptor- and low pH-dependent manner. This feature allowed capturing the virus in intracellular compartments through raising the endosomal pH. Virus fusion was synchronously initiated upon permitting endosome acidification and visualized in real-time by single particle imaging. We found that different receptor isoforms directed virus into distinct sub-cellular compartments supporting quick release of the viral core. Through tracking individual sub-viral particles released from endosomes, we found that the full length receptor mediated core delivery into the cytoplasm. By contrast, fusion mediated by the GPI-anchored receptor released the core into another endosomal compartment, from which the core entered the cytosol through an additional temperature-dependent step. These findings demonstrate different permissiveness of endosomal compartments to viral fusion and the existence of a post-fusion step leading to the cytosolic release of cores and initiation of infection.
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Affiliation(s)
- Sergi Padilla-Parra
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
| | - Mariana Marin
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
| | - Naoyuki Kondo
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
| | - Gregory B. Melikyan
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia, United States of America
- Children's Healthcare of Atlanta, Atlanta, Georgia, United States of America
- * E-mail:
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35
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Gao Y, Sun Y, Li Z, Liu QM, Liu WH, He XH. [The research progress of foamy virus Bet protein]. Bing Du Xue Bao 2012; 28:285-290. [PMID: 22764533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Foamy virus can establish lifelong persistent infection in mammal hosts without inducing diseases. Such special characteristic stimulates the interests of researchers. As reported, the accessory protein Bet of foamy virus could regulate the gene expression and infection cycle of foamy virus and take part in the generation of chronic viral infection. And also, Bet might prevent the host cellular defense factor APO-BEC3 from interfering the replication of virus and play a role in maintaining viral persistent infection. In order to elucidate the roles of Bet in the foamy virus replication and infection, this review summarized the research progress of Bet protein reported in recent years.
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Affiliation(s)
- Yuan Gao
- College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
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Lamb D, Schüttelkopf AW, van Aalten DMF, Brighty DW. Charge-surrounded pockets and electrostatic interactions with small ions modulate the activity of retroviral fusion proteins. PLoS Pathog 2011; 7:e1001268. [PMID: 21304939 PMCID: PMC3033372 DOI: 10.1371/journal.ppat.1001268] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 12/31/2010] [Indexed: 11/25/2022] Open
Abstract
Refolding of viral class-1 membrane fusion proteins from a native state to a trimer-of-hairpins structure promotes entry of viruses into cells. Here we present the structure of the bovine leukaemia virus transmembrane glycoprotein (TM) and identify a group of asparagine residues at the membrane-distal end of the trimer-of-hairpins that is strikingly conserved among divergent viruses. These asparagines are not essential for surface display of pre-fusogenic envelope. Instead, substitution of these residues dramatically disrupts membrane fusion. Our data indicate that, through electrostatic interactions with a chloride ion, the asparagine residues promote assembly and profoundly stabilize the fusion-active structures that are required for viral envelope-mediated membrane fusion. Moreover, the BLV TM structure also reveals a charge-surrounded hydrophobic pocket on the central coiled coil and interactions with basic residues that cluster around this pocket are critical to membrane fusion and form a target for peptide inhibitors of envelope function. Charge-surrounded pockets and electrostatic interactions with small ions are common among class-1 fusion proteins, suggesting that small molecules that specifically target such motifs should prevent assembly of the trimer-of-hairpins and be of value as therapeutic inhibitors of viral entry. Human T-cell leukaemia virus types-1 (HTLV-1) and bovine leukaemia virus (BLV) are divergent blood borne viruses that cause hematological malignancies in humans and cattle respectively. In common with other enveloped viruses, infection of cells by HTLV-1 and BLV is dependent on the membrane fusion properties of the viral envelope glycoproteins. Here we have solved the crystal structure of the BLV transmembrane glycoprotein, and, through a functional and comparative analysis with HTLV-1, we have identified features that are critical to fusion protein function. In particular, we demonstrate that electrostatic interactions with small ions dramatically stabilize the assembly and fusion-associated forms of the BLV TM, but are not required for the cell surface display of native pre-fusogenic envelope. Moreover, we show that charged residues that border a deep hydrophobic pocket contribute directly to appropriate folding of fusion-active envelope and are critical to membrane fusion. Importantly, the charged residues that border the pocket are key features that determine the specificity and activity of peptide inhibitors of envelope function. Our study demonstrates that charge-surrounded pockets and electrostatic interactions with small ions are significant leitmotifs of diverse class-1 fusion proteins and that these elements represent ideal targets for novel small-molecule inhibitors of viral entry.
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Affiliation(s)
- Daniel Lamb
- The Biomedical Research Institute, College of Medicine, Ninewells Hospital, The University of Dundee, Dundee, United Kingdom
| | - Alexander W. Schüttelkopf
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Daan M. F. van Aalten
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - David W. Brighty
- The Biomedical Research Institute, College of Medicine, Ninewells Hospital, The University of Dundee, Dundee, United Kingdom
- * E-mail:
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Elrouby N, Bureau TE. Bs1, a new chimeric gene formed by retrotransposon-mediated exon shuffling in maize. Plant Physiol 2010; 153:1413-24. [PMID: 20488894 PMCID: PMC2899935 DOI: 10.1104/pp.110.157420] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 05/16/2010] [Indexed: 05/19/2023]
Abstract
Transposons are major components of all eukaryotic genomes. Although traditionally regarded as causes of detrimental mutations, recent evidence suggests that transposons may play a role in host gene diversification and evolution. For example, host gene transduction by retroelements has been suggested to be both common and to have the potential to create new chimeric genes by the shuffling of existing sequences. We have previously shown that the maize (Zea mays subsp. mays) retrotransposon Bs1 has transduced sequences from three different host genes. Here, we provide evidence that these transduction events led to the generation of a chimeric new gene that is both transcribed and translated. Expression of Bs1 is tightly controlled and occurs during a narrow developmental window in early ear development. Although all Bs1-associated transduction events took place before Zea speciation, a full uninterrupted open reading frame encoding the BS1 protein may have arisen in domesticated maize or in the diverse populations of its progenitor Z. mays subsp. parviglumis. We discuss potential functions based on domain conservation and evidence for functional constraints between the transduced sequences and their host gene counterparts.
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Affiliation(s)
- Nabil Elrouby
- Department of Biology, McGill University, Montreal, Quebec, Canada.
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Jia B, Serra-Moreno R, Neidermyer W, Rahmberg A, Mackey J, Fofana IB, Johnson WE, Westmoreland S, Evans DT. Species-specific activity of SIV Nef and HIV-1 Vpu in overcoming restriction by tetherin/BST2. PLoS Pathog 2009; 5:e1000429. [PMID: 19436700 PMCID: PMC2673686 DOI: 10.1371/journal.ppat.1000429] [Citation(s) in RCA: 315] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 04/14/2009] [Indexed: 01/14/2023] Open
Abstract
Tetherin, also known as BST2, CD317 or HM1.24, was recently identified as an interferon-inducible host–cell factor that interferes with the detachment of virus particles from infected cells. HIV-1 overcomes this restriction by expressing an accessory protein, Vpu, which counteracts tetherin. Since lentiviruses of the SIVsmm/mac/HIV-2 lineage do not have a vpu gene, this activity has likely been assumed by other viral gene products. We found that deletion of the SIVmac239 nef gene significantly impaired virus release in cells expressing rhesus macaque tetherin. Virus release could be restored by expressing Nef in trans. However, Nef was unable to facilitate virus release in the presence of human tetherin. Conversely, Vpu enhanced virus release in the presence of human tetherin, but not in the presence of rhesus tetherin. In accordance with the species-specificity of Nef in mediating virus release, SIV Nef downregulated cell-surface expression of rhesus tetherin, but did not downregulate human tetherin. The specificity of SIV Nef for rhesus tetherin mapped to four amino acids in the cytoplasmic domain of the molecule that are missing from human tetherin, whereas the specificity of Vpu for human tetherin mapped to amino acid differences in the transmembrane domain. Nef alleles of SIVsmm, HIV-2 and HIV-1 were also able to rescue virus release in the presence of both rhesus macaque and sooty mangabey tetherin, but were generally ineffective against human tetherin. Thus, the ability of Nef to antagonize tetherin from these Old World primates appears to be conserved among the primate lentiviruses. These results identify Nef as the viral gene product of SIV that opposes restriction by tetherin in rhesus macaques and sooty mangabeys, and reveal species-specificity in the activities of both Nef and Vpu in overcoming tetherin in their respective hosts. Tetherin was recently identified as a host–cell factor that interferes with the detachment of virus particles from infected cells. HIV-1 overcomes the antiviral effects of tetherin by expressing Vpu, which mediates the degradation of tetherin. While tetherin has broad activity against diverse types of viruses, only a few of the primate AIDS viruses express Vpu. Simian immunodeficiency virus (SIV) does not have a vpu gene. Since SIV infection of the rhesus macaque is an important animal model for AIDS vaccine development, we set out to determine how SIV overcomes restriction by tetherin in this species. We found that the SIV Nef protein could counteract rhesus macaque tetherin, but not human tetherin. Conversely, the HIV-1 Vpu protein counteracted human tetherin, but not rhesus tetherin. The specificity of Nef for rhesus tetherin mapped to four amino acids in the cytoplasmic domain of the molecule that are missing from human tetherin, whereas the specificity of Vpu for human tetherin mapped to amino acid differences in the transmembrane domain. These observations identify a role for the SIV Nef protein in counteracting tetherin, and reveal species-specificity in the activities of both Nef and Vpu in overcoming tetherin in their respective hosts.
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Affiliation(s)
- Bin Jia
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Ruth Serra-Moreno
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - William Neidermyer
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Andrew Rahmberg
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - John Mackey
- Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Ismael Ben Fofana
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Welkin E. Johnson
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - Susan Westmoreland
- Department of Pathology, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
| | - David T. Evans
- Department of Microbiology and Molecular Genetics, Harvard Medical School, New England Primate Research Center, Southborough, Massachusetts, United States of America
- * E-mail:
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Gärtner K, Wiktorowicz T, Park J, Mergia A, Rethwilm A, Scheller C. Accuracy estimation of foamy virus genome copying. Retrovirology 2009; 6:32. [PMID: 19348676 PMCID: PMC2678077 DOI: 10.1186/1742-4690-6-32] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 04/06/2009] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Foamy viruses (FVs) are the most genetically stable viruses of the retrovirus family. This is in contrast to the in vitro error rate found for recombinant FV reverse transcriptase (RT). To investigate the accuracy of FV genome copying in vivo we analyzed the occurrence of mutations in HEK 293T cell culture after a single round of reverse transcription using a replication-deficient vector system. Furthermore, the frequency of FV recombination by template switching (TS) and the cross-packaging ability of different FV strains were analyzed. RESULTS We initially sequenced 90,000 nucleotides and detected 39 mutations, corresponding to an in vivo error rate of approximately 4 x 10-4 per site per replication cycle. Surprisingly, all mutations were transitions from G to A, suggesting that APOBEC3 activity is the driving force for the majority of mutations detected in our experimental system. In line with this, we detected a late but significant APOBEC3G and 3F mRNA by quantitative PCR in the cells. We then analyzed 170,000 additional nucleotides from experiments in which we co-transfected the APOBEC3-interfering foamy viral bet gene and observed a significant 50% drop in G to A mutations, indicating that APOBEC activity indeed contributes substantially to the foamy viral replication error rate in vivo. However, even in the presence of Bet, 35 out of 37 substitutions were G to A, suggesting that residual APOBEC activity accounted for most of the observed mutations. If we subtract these APOBEC-like mutations from the total number of mutations, we calculate a maximal intrinsic in vivo error rate of 1.1 x 10-5 per site per replication. In addition to the point mutations, we detected one 49 bp deletion within the analyzed 260000 nucleotides.Analysis of the recombination frequency of FV vector genomes revealed a 27% probability for a template switching (TS) event within a 1 kilobase (kb) region. This corresponds to a 98% probability that FVs undergo at least one additional TS event per replication cycle. We also show that a given FV particle is able to cross-transfer a heterologous FV genome, although at reduced efficiency than the homologous vector. CONCLUSION Our results indicate that the copying of the FV genome is more accurate than previously thought. On the other hand recombination among FV genomes appears to be a frequent event.
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Affiliation(s)
- Kathleen Gärtner
- Universität Würzburg, Institut für Virologie und Immunbiologie, Versbacher Str 7, 97078, Würzburg, Germany
| | - Tatiana Wiktorowicz
- Universität Würzburg, Institut für Virologie und Immunbiologie, Versbacher Str 7, 97078, Würzburg, Germany
| | - Jeonghae Park
- Department of Infectious Disease and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Ayalew Mergia
- Department of Infectious Disease and Pathology, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
| | - Axel Rethwilm
- Universität Würzburg, Institut für Virologie und Immunbiologie, Versbacher Str 7, 97078, Würzburg, Germany
| | - Carsten Scheller
- Universität Würzburg, Institut für Virologie und Immunbiologie, Versbacher Str 7, 97078, Würzburg, Germany
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Sinha-Datta U, Datta A, Ghorbel S, Dodon MD, Nicot C. Human T-cell lymphotrophic virus type I rex and p30 interactions govern the switch between virus latency and replication. J Biol Chem 2007; 282:14608-15. [PMID: 17360706 DOI: 10.1074/jbc.m611219200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human T-cell lymphotrophic virus type I Rex and p30 are both RNA binding regulatory proteins. Rex is a protein that interacts with a responsive element and stimulates nuclear export of incompletely spliced viral RNAs thereby increasing production of virus particles. In contrast, p30 is involved in the nuclear retention of the tax/rex mRNA leading to inhibition of virus expression and possible establishment of viral latency. How these two proteins, with apparent opposite functions, integrate in the viral replication cycle is unknown. Here, we demonstrate that Rex and p30 form ribonucleoprotein ternary complexes onto specific viral mRNA. Our results explain the selective nuclear retention of tax/rex but not other viral mRNAs by p30. Whereas p30 suppresses Rex expression, it did not affect Rex-mediated nuclear export of RNA containing the Rex response element. In contrast, Rex was able to counteract p30-mediated suppression of viral expression and restore cytoplasmic tax/rex mRNA and Tax protein expression. Together, our data demonstrate a complex regulatory mechanism of antagonizing post-transcriptional regulators evolved by human T-cell lymphotrophic virus type I to allow a vigilant control of viral gene expression.
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Affiliation(s)
- Uma Sinha-Datta
- Department of Microbiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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41
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Abstract
Retroviruses make a long and complex journey from outside the cell to the nucleus in the early stages of infection, and then an equally long journey back out again in the late stages of infection. Ongoing efforts are identifying an enormous array of cellular proteins that are used by the viruses in the course of their travels. These host factors are potential new targets for therapeutic intervention.
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Affiliation(s)
- Stephen P Goff
- Department of Biochemistry and Molecular Biophysics, Howard Hughes Medical Institute HHSC 1310c, College of Physicians and Surgeons, Columbia University, 701 West 168th Street, New York, New York 10032, USA.
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Younis I, Boris-Lawrie K, Green PL. Human T-cell leukemia virus open reading frame II encodes a posttranscriptional repressor that is recruited at the level of transcription. J Virol 2007; 80:181-91. [PMID: 16352542 PMCID: PMC1317543 DOI: 10.1128/jvi.80.1.181-191.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Human T-cell leukemia virus (HTLV) infection is a chronic, lifelong infection that is associated with the development of leukemia and neurological disease after a long latency period, and the mechanism by which the virus is able to evade host immune surveillance is elusive. Besides the structural and enzymatic proteins, HTLV encodes regulatory (Tax and Rex) and accessory (open reading frame I [ORF I] and ORF II) proteins. Tax activates viral and cellular transcription and promotes T-cell growth and malignant transformation. Rex acts posttranscriptionally to facilitate cytoplasmic expression of incompletely spliced viral mRNAs. Recently, we reported that the accessory gene products of HTLV-1 and HTLV-2 ORF II (p30II and p28II, respectively) are able to restrict viral replication. These proteins act as negative regulators of both Tax and Rex by binding to and retaining their mRNA in the nucleus, leading to reduced protein expression and virion production. Here, we show that p28II is recruited to the viral promoter in a Tax-dependent manner. After recruitment to the promoter, p28II or p30II then travels with the transcription elongation machinery until its target mRNA is synthesized. Experiments artificially directing these proteins to the promoter indicate that p28II, unlike HTLV-1 p30II, displays no transcriptional activity. Furthermore, the tethering of p28II directly to tax/rex mRNA resulted in repression of Tax function, which could be attributed to the ability of p28II to block TAP/p15-mediated enhancement of Tax expression. p28II-mediated reduction of viral replication in infected cells may permit survival of the cells by allowing escape from immune recognition, which is consistent with the critical role of HTLV accessory proteins in viral persistence in vivo.
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Affiliation(s)
- Ihab Younis
- Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Rd., Columbus, OH 43210, USA
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Bodem J, Kräusslich HG, Rethwilm A. Acetylation of the foamy virus transactivator Tas by PCAF augments promoter-binding affinity and virus transcription. J Gen Virol 2007; 88:259-263. [PMID: 17170459 DOI: 10.1099/vir.0.82169-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
It was shown recently that retrovirus transactivators interact with transcriptional coactivators, such as histone acetyltransferases (HATs). Foamy viruses (FVs) direct gene expression from the long terminal repeat and from an internal promoter. The activity of both promoters is strictly dependent on the DNA-binding transactivator Tas. Recently, it was shown that Tas interacts with the HATs p300 and PCAF. Based on these findings, it is demonstrated here that PCAF has the ability to acetylate Tas in vitro and in vivo. Tas acetylation resulted in enhanced DNA binding to the virus promoters. In vitro transcription reactions on non-chromatinized template showed that only acetylated Tas enhanced transcription significantly. These results demonstrate that acetylation of the FV transactivator Tas may be an effective means to regulate virus transcription.
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Affiliation(s)
- Jochen Bodem
- Institut für Virologie und Immunbiologie, Universität Würzburg, Germany
- Institut für Virologie, Universität Heidelberg, Germany
| | | | - Axel Rethwilm
- Institut für Virologie und Immunbiologie, Universität Würzburg, Germany
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Baydoun H, Duc-Dodon M, Lebrun S, Gazzolo L, Bex F. Regulation of the human T-cell leukemia virus gene expression depends on the localization of regulatory proteins Tax, Rex and p30II in specific nuclear subdomains. Gene 2007; 386:191-201. [PMID: 17071021 DOI: 10.1016/j.gene.2006.09.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Revised: 08/31/2006] [Accepted: 09/07/2006] [Indexed: 12/11/2022]
Abstract
The human T-cell leukemia virus HTLV-1 encodes regulatory proteins, Tax, Rex and p30(II), which are involved in the control of viral gene expression at the transcriptional and post-transcriptional levels. Tax localizes in unique nuclear bodies that contain components of the transcription and splicing complexes. In this work, we studied the relative intracellular localizations of Tax, Rex and p30(II). Run-on transcription assays and immunocytochemistry at light and electron microscopy levels indicated that the Tax nuclear bodies included both de novo transcribed RNA and the RNA polymerase II form that is phosphorylated on its carboxy-terminal domain whereas contacts with chromatin were observed at the periphery of these nuclear bodies. Rex first accumulated in nucleolar foci and then spread across the whole nucleus to display a diffuse and punctuate nucleoplasmic distribution. This distribution of Rex was observed in HTLV-1 transformed lymphocytes and in COS cells expressing the HTLV-1 provirus. Rex colocalized with the cellular export factor CRM-1 in the nucleolar foci as well as in the nucleoplasmic foci that did not overlap with Tax nuclear bodies but were found at the boundaries of the Tax bodies. In addition, we demonstrate that p30(II) interacts with Rex and colocalizes with the Rex/CRM-1 complexes in the nucleoli leading to their clearance from the nucleoplasm. Our results suggest that transcripts originating from Tax-induced activation of gene expression at the boundaries of the Tax bodies are transported out of the nucleus by nucleoplasmic Rex/CRM-1 complexes that are first assembled in nucleolar foci. In addition, p30(II) might exert its negative effect on viral RNA transport by preventing the release of the Rex/CRM-1 complexes from sequestration in nucleolar foci. These data support the idea that the transcriptional and post-transcriptional regulation of HTLV-1 gene expression depends on the concentration of select regulatory complexes at specific area of the nucleus.
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Affiliation(s)
- Hicham Baydoun
- Institute for Microbiological Research J-M Wiame and Laboratory of Microbiology, University of Brussels, Belgium
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Chen LM, Briones G, Donis RO, Galán JE. Optimization of the delivery of heterologous proteins by the Salmonella enterica serovar Typhimurium type III secretion system for vaccine development. Infect Immun 2006; 74:5826-33. [PMID: 16988261 PMCID: PMC1594939 DOI: 10.1128/iai.00375-06] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Type III protein secretion systems, which are organelles with the capacity to deliver bacterial proteins into host cells, have been adapted to deliver heterologous antigens for vaccine development. A limitation of these antigen delivery systems is that some proteins are not amenable to secretion through this pathway. We show here that proteins from the simian and human immunodeficiency viruses that are not permissive for secretion through a Salmonella enterica serovar Typhimurium type III secretion system can be modified to travel this secretion pathway by introduction of discrete mutations. Proteins optimized for secretion were presented more efficiently via the major histocompatibility complex class I pathway and were able to induce a better immune response.
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Affiliation(s)
- Li-Mei Chen
- Section of Microbial Pathogenesis, School of Medicine, Yale University, New Haven, CT 06536, USA
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Schröfelbauer B, Senger T, Manning G, Landau NR. Mutational alteration of human immunodeficiency virus type 1 Vif allows for functional interaction with nonhuman primate APOBEC3G. J Virol 2006; 80:5984-91. [PMID: 16731937 PMCID: PMC1472613 DOI: 10.1128/jvi.00388-06] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human APOBEC3F (hA3F) and APOBEC3G (hA3G) are antiretroviral cytidine deaminases that can be encapsidated during virus assembly to catalyze C-->U deamination of the viral reverse transcripts in the next round of infection. Lentiviruses such as human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) have evolved the accessory protein Vif to induce their degradation before packaging. HIV type 1 (HIV-1) Vif counteracts hA3G but not rhesus macaque APOBEC3G (rhA3G) or African green monkey (AGM) APOBEC3G (agmA3G) because of a failure to bind the nonhuman primate proteins. The species specificity of the interaction is controlled by amino acid 128, which is aspartate in hA3G and lysine in rhA3G. With the objective of overcoming this species restriction, mutations were introduced into HIV-1 Vif at amino acid positions that differed in charge between HIV-1 Vif and SIV Vif. The mutant proteins were tested for the ability to counteract hA3G, rhA3G, and agmA3G. Alteration of the conserved sequence at positions 14 to 17 from DRMR to SERQ, which is the sequence in AGM Vif, caused HIV-1 Vif to functionally interact with rhA3G and agmA3G. Mutation of three residues to the sequence SEMQ allowed interaction with rhA3G. SEMQ Vif also counteracted D128K mutant hA3G and wild-type hA3G. Introduction of the sequence into an infectious molecular HIV-1 clone allowed the virus to replicate productively in human cells that expressed rhA3G or hA3G. These findings provide insight into the interaction of Vif with A3G and are a step toward the development of a novel primate model for AIDS.
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Affiliation(s)
- Bärbel Schröfelbauer
- Infectious Disease Laboratory, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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Hamamoto S, Nishitsuji H, Amagasa T, Kannagi M, Masuda T. Identification of a novel human immunodeficiency virus type 1 integrase interactor, Gemin2, that facilitates efficient viral cDNA synthesis in vivo. J Virol 2006; 80:5670-7. [PMID: 16731905 PMCID: PMC1472599 DOI: 10.1128/jvi.02471-05] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Retroviral integrase (IN) catalyzes the integration of viral cDNA into a host chromosome. Additional roles have been suggested for IN, including uncoating, reverse transcription, and nuclear import of the human immunodeficiency virus type 1 (HIV-1) genome. However, the underlying mechanism is largely unknown. Here, using a yeast two-hybrid system, we identified a survival motor neuron (SMN)-interacting protein 1 (Gemin2) that binds to HIV-1 IN. Reduction of Gemin2 with small interfering RNA duplexes (siGemin2) dramatically reduced HIV-1 infection in human primary monocyte-derived macrophages and also reduced viral cDNA synthesis. In contrast, siGemin2 did not affect HIV-1 expression from the integrated proviral DNA. Although Gemin2 was undetectable in cell-free viral particles, coimmunoprecipitation experiments using FLAG-tagged Gemin2 strongly suggested that Gemin2 interacts with the incoming viral genome through IN. Further experiments reducing SMN or other SMN-interacting proteins suggested that Gemin2 might act on HIV-1 either alone or with unknown proteins to facilitate efficient viral cDNA synthesis soon after infection. Thus, we provide the evidence for a novel host protein that binds to HIV-1 IN and facilitates viral cDNA synthesis and subsequent steps that precede integration in vivo.
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Affiliation(s)
- Seiji Hamamoto
- Department of Immunotherapeutics, Tokyo Medical and Dental University, Tokyo 113-8519, Japan
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Michael B, Nair AM, Datta A, Hiraragi H, Ratner L, Lairmore MD. Histone acetyltransferase (HAT) activity of p300 modulates human T lymphotropic virus type 1 p30II-mediated repression of LTR transcriptional activity. Virology 2006; 354:225-39. [PMID: 16890266 PMCID: PMC3044896 DOI: 10.1016/j.virol.2006.07.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 02/22/2006] [Accepted: 07/05/2006] [Indexed: 01/28/2023]
Abstract
Human T-lymphotropic virus type-1 (HTLV-1) is a deltaretrovirus that causes adult T cell leukemia/lymphoma, and is implicated in a variety of lymphocyte-mediated inflammatory disorders. HTLV-1 provirus has regulatory and accessory genes in four pX open reading frames. HTLV-1 pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in virus replication or pathogenesis. We have demonstrated that pX ORF-II mutations block virus replication in vivo and that ORF-II encoded p30II, a nuclear-localizing protein that binds with CREB-binding protein (CBP)/p300, represses CREB and Tax responsive element (TRE)-mediated transcription. Herein, we have identified p30II motifs important for p300 binding and in regulating TRE-mediated transcription in the absence and presence of HTLV-1 provirus. Within amino acids 100-179 of p30II, a region important for repression of LTR-mediated transcription, we identified a single lysine residue at amino acid 106 (K3) that significantly modulates the ability of p30II to repress TRE-mediated transcription. Exogenous p300, in a dose-responsive manner, reverses p30II-dependent repression of TRE-mediated transcription, in the absence or presence of the provirus, In contrast to wild type p300, p300 HAT mutants (defective in histone acetyltransferase activity) only partially rescued p30(II)-mediated LTR repression. Deacetylation by histone deacetylase-1 (HDAC-1) enhanced p30II-mediated LTR repression, while inhibition of deacetylation by trichostatin A decreases p30(II)-mediated LTR repression. Collectively, our data indicate that HTLV-1 p30II modulates viral gene expression in a cooperative manner with p300-mediated acetylation.
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Affiliation(s)
- Bindhu Michael
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Amrithraj M. Nair
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Antara Datta
- The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Hajime Hiraragi
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
| | - Lee Ratner
- Department of Medicine, Pathology, and Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Michael D. Lairmore
- Center for Retrovirus Research and Department of Veterinary Biosciences, The Ohio State University, Columbus, OH 43210, USA
- Department of Molecular Virology, Immunology and Medical Genetics, The Ohio State University, Columbus, OH 43210, USA
- Comprehensive Cancer Center, The Arthur G. James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH 43210, USA
- Corresponding author. Department of Veterinary Biosciences, The Ohio State University, 1925 Coffey Road, Columbus, OH 43210, USA. Fax: +1 614 292 6473., (M.D. Lairmore)
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Datta A, Sinha-Datta U, Dhillon NK, Buch S, Nicot C. The HTLV-I p30 Interferes with TLR4 Signaling and Modulates the Release of Pro- and Anti-inflammatory Cytokines from Human Macrophages. J Biol Chem 2006; 281:23414-24. [PMID: 16785240 DOI: 10.1074/jbc.m600684200] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Whereas adaptive immunity has been extensively studied, very little is known about the innate immunity of the host to HTLV-I infection. HTLV-I-infected ATL patients have pronounced immunodeficiency associated with frequent opportunistic infections, and in these patients, concurrent infections with bacteria and/or parasites are known to increase risks of progression to ATL. The Toll-like receptor-4 (TLR4) activation in response to bacterial infection is essential for dendritic cell maturation and links the innate and adaptive immune responses. Recent reports indicate that TLR4 is targeted by viruses such as RSV, HCV, and MMTV. Here we report that HTLV-I has also evolved a protein that interferes with TLR4 signaling; p30 interacts with and inhibits the DNA binding and transcription activity of PU.1 resulting in the down-regulation of the TLR4 expression from the cell surface. Expression of p30 hampers the release of pro-inflammatory cytokines MCP-1, TNF-alpha, and IL-8 and stimulates release of anti-inflammatory IL-10 following stimulation of TLR4 in human macrophage. Finally, we found that p30 increases phosphorylation and inactivation of GSK3-beta a key step for IL-10 production. Our study suggests a novel function of p30, which may instigate immune tolerance by reducing activation of adaptive immunity in ATL patients.
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Affiliation(s)
- Abhik Datta
- Department of Microbiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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Abstract
The HIV and SIV gp41 ectodomains are extremely stable to chemical and thermal denaturation and the observed stability has been proposed to be an important thermodynamic driving force for gp41-mediated fusion of the viral and target cell membranes. The importance of the disulphide bond and surrounding residues within the HIV gp41 loop have been assayed by DSC studies of wild type and mutant HIV gp41. Based on the thermal transition temperature, the disulphide bond and surrounding residues do not contribute to the thermal stability of gp41 and thus do not contribute to gp41-mediated membrane fusion.
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Affiliation(s)
- Amy Jacobs
- Department of Biochemistry and Molecular Genetics,University of Illinois at Chicago, Chicago, IL 60607, USA
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