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Mohanty S, Harhaj EW. Mechanisms of Innate Immune Sensing of HTLV-1 and Viral Immune Evasion. Pathogens 2023; 12:pathogens12050735. [PMID: 37242405 DOI: 10.3390/pathogens12050735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Human T lymphotropic virus-1 (HTLV-1) was the first identified oncoretrovirus, which infects and establishes a persistent infection in approximately 10-20 million people worldwide. Although only ~5% of infected individuals develop pathologies such as adult T-cell leukemia/lymphoma (ATLL) or a neuroinflammatory disorder termed HTLV-1-asssociated myelopathy/tropical spastic paraparesis (HAM/TSP), asymptomatic carriers are more susceptible to opportunistic infections. Furthermore, ATLL patients are severely immunosuppressed and prone to other malignancies and other infections. The HTLV-1 replication cycle provides ligands, mainly nucleic acids (RNA, RNA/DNA intermediates, ssDNA intermediates, and dsDNA), that are sensed by different pattern recognition receptors (PRRs) to trigger immune responses. However, the mechanisms of innate immune detection and immune responses to HTLV-1 infection are not well understood. In this review, we highlight the functional roles of different immune sensors in recognizing HTLV-1 infection in multiple cell types and the antiviral roles of host restriction factors in limiting persistent infection of HTLV-1. We also provide a comprehensive overview of intricate strategies employed by HTLV-1 to subvert the host innate immune response that may contribute to the development of HTLV-1-associated diseases. A more detailed understanding of HTLV-1-host pathogen interactions may inform novel strategies for HTLV-1 antivirals, vaccines, and treatments for ATLL or HAM/TSP.
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Affiliation(s)
- Suchitra Mohanty
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, PA 17033, USA
| | - Edward W Harhaj
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, PA 17033, USA
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2
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Panda M, Kalita E, Rao A, Prajapati VK. Mechanism of cell cycle regulation and cell proliferation during human viral infection. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 135:497-525. [PMID: 37061340 DOI: 10.1016/bs.apcsb.2022.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Over the history of the coevolution of Host viral interaction, viruses have customized the host cellular machinery into their use for viral genome replication, causing effective infection and ultimately aiming for survival. They do so by inducing subversions to the host cellular pathways like cell cycle via dysregulation of important cell cycle checkpoints by viral encoded proteins, arresting the cell cycle machinery, blocking cytokinesis as well as targeting subnuclear bodies, thus ultimately disorienting the cell proliferation. Both DNA and RNA viruses have been active participants in such manipulation resulting in serious outcomes of cancer. They achieve this by employing different mechanisms-Protein-protein interaction, protein-phosphorylation, degradation, redistribution, viral homolog, and viral regulation of APC at different stages of cell cycle events. Several DNA viruses cause the quiescent staged cells to undergo cell cycle which increases nucleotide pools logistically significantly persuading viral replication whereas few other viruses arrest a particular stage of cell cycle. This allows the latter group to sustain the infection which allows them to escape host immune response and support viral multiplication. Mechanical study of signaling such viral mediated pathways could give insight into understanding the etiology of tumorigenesis and progression. Overall this chapter highlights the possible strategies employed by DNA/RNA viral families which impact the normal cell cycle but facilitate viral infected cell replication. Such information could contribute to comprehending viral infection-associated disorders to further depth.
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Affiliation(s)
- Mamta Panda
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Elora Kalita
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Abhishek Rao
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India
| | - Vijay Kumar Prajapati
- Department of Biochemistry, School of Life Sciences, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, India; Department of Biochemistry, School of Biological Sciences, Central University of Punjab, Bathinda, Punjab, India.
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3
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Li HL, Cheng Y, Zhou ZW, Long HZ, Luo HY, Wen DD, Cheng L, Gao LC. Isoliensinine induces cervical cancer cell cycle arrest and apoptosis by inhibiting the AKT/GSK3α pathway. Oncol Lett 2021; 23:8. [PMID: 34820007 PMCID: PMC8607237 DOI: 10.3892/ol.2021.13126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 10/20/2021] [Indexed: 12/26/2022] Open
Abstract
Isoliensinine is a bis-benzylisoquinoline alkaloid that can be isolated from the lotus Nelumbo nucifera Gaertn. It has been reported to exert a variety of anti-cancer properties. In the present study, the potential effects of isoliensinine on cervical cancer Siha, HeLa, Caski and C33A cell lines were investigated by using Cell Counting Kit-8 (CCK-8), flow cytometry, western blotting and reverse transcription-PCR (RT-PCR) to measure cell proliferation, the cell cycle and apoptosis, in addition to elucidating the underlying molecular mechanism. Protein levels of p21, CDK2, Cyclin E, Mcl-1, cleaved Caspase-9, AKT, phosphorylated-AKT, glycogen synthase kinase (Gsk)3α, PTEN, and mRNA levels of p21, p15, p27, CDK2, CDK4, Cyclin E, Cyclin D, Gsk3α, Gsk3β and PTEN were measured. Molecular docking assays were used to calculate the strength of binding of isoliensinine to AKT using AutoDock 4.0. Isoliensinine was found to induce cell cycle arrest at the G0/G1 phase by upregulating p21 expression and downregulating CDK2 and cyclin E in cervical cancer cells. In addition, in previous research, isoliensinine promoted cell apoptosis by downregulating myeloid-cell leukemia 1 expression and activating caspase-9. Upstream, isoliensinine significantly downregulated AKT (S473) phosphorylation and GSK3α expression in a dose- and time-dependent manner. The AKT inhibitor AKTi-1/2 enhanced the function of isoliensinine on cell cycle arrest and apoptosis through the AKT/GSK3α pathway. AutoDock analysis showed that isoliensinine can bind to the AKT protein. These findings suggest that isoliensinine can induce cervical cancer cell cycle arrest and apoptosis by inhibiting the AKT/GSK3α pathway, which represents a novel strategy for the treatment of cervical cancer.
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Affiliation(s)
- Hong-Li Li
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,School of Life Science, Hunan University of Science and Technology, Xiangtan, Hunan 411201, P.R. China
| | - Yan Cheng
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research Affiliated to School of Pharmacy, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Zi-Wei Zhou
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research Affiliated to School of Pharmacy, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Hui-Zhi Long
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research Affiliated to School of Pharmacy, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Hong-Yu Luo
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research Affiliated to School of Pharmacy, University of South China, Hengyang, Hunan 421001, P.R. China
| | - Dan-Dan Wen
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China
| | - Lin Cheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Li-Chen Gao
- Department of Pharmacy, Cancer Institute, Phase I Clinical Trial Centre, Changsha Central Hospital Affiliated to University of South China, School of Pharmacy, University of South China, Changsha, Hunan 410000, P.R. China.,Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research Affiliated to School of Pharmacy, University of South China, Hengyang, Hunan 421001, P.R. China
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4
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Dai X, Hakizimana O, Zhang X, Kaushik AC, Zhang J. Orchestrated efforts on host network hijacking: Processes governing virus replication. Virulence 2021; 11:183-198. [PMID: 32050846 PMCID: PMC7051146 DOI: 10.1080/21505594.2020.1726594] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
With the high pervasiveness of viral diseases, the battle against viruses has never ceased. Here we discuss five cellular processes, namely "autophagy", "programmed cell death", "immune response", "cell cycle alteration", and "lipid metabolic reprogramming", that considerably guide viral replication after host infection in an orchestrated manner. On viral infection, "autophagy" and "programmed cell death" are two dynamically synchronized cell survival programs; "immune response" is a cell defense program typically suppressed by viruses; "cell cycle alteration" and "lipid metabolic reprogramming" are two altered cell housekeeping programs tunable in both directions. We emphasize on their functionalities in modulating viral replication, strategies viruses have evolved to tune these processes for their benefit, and how these processes orchestrate and govern cell fate upon viral infection. Understanding how viruses hijack host networks has both academic and industrial values in providing insights toward therapeutic strategy design for viral disease control, offering useful information in applications that aim to use viral vectors to improve human health such as gene therapy, and providing guidelines to maximize viral particle yield for improved vaccine production at a reduced cost.
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Affiliation(s)
- Xiaofeng Dai
- The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | | | - Xuanhao Zhang
- Wuxi School of Medicine, Jiangnan University, Wuxi, China
| | - Aman Chandra Kaushik
- School of Life Sciences and Biotechnology, Shanghai JiaoTong University, Shanghai, China
| | - Jianying Zhang
- Henan Academy of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, Henan, China.,Department of Biological Sciences, University of Texas at El Paso, EI Paso, TX, USA
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5
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Levy D, Ferreira MCMR, Reichert CO, de Almeida LV, Brocardo G, Lage LAPC, Culler HF, Nukui Y, Bydlowski SP, Pereira J. Cell Cycle Changes, DNA Ploidy, and PTTG1 Gene Expression in HTLV-1 Patients. Front Microbiol 2020; 11:1778. [PMID: 32793179 PMCID: PMC7393187 DOI: 10.3389/fmicb.2020.01778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 07/07/2020] [Indexed: 11/13/2022] Open
Abstract
Human T-cell lymphotropic virus type-1 (HTLV-1) is a pathogenic retrovirus that is associated with adult T-cell leukemia/lymphoma (ATL). Genetic instability is the hallmark of ATL. Cell cycle progression is needed for virus particle reproduction. HTLV-1 encoded Tax protein ultimately disrupts the mitotic spindle checkpoint, leading to incorrect chromosome segregation, resulting in aneuploidy. Cell cycle abnormalities have been described in T cells transfected with HTLV-1 virus in vitro, but not in HTLV-1 asymptomatic carriers. PTTG1 and HTLV-1 viral protein Tax exhibit a cooperative transforming activity. Overexpressed PTTG1 results in chromosome instability and aneuploidy, which has been suggested as a mechanism underlying PTTG1 transforming activity. Here we aimed to investigate cell cycle, DNA ploidy and PTTG1 mRNA expression in CD4+ and CD8+ T cells in healthy subjects (HS), HTLV-1 asymptomatic carriers and ATL patients. We have identified that HTLV-1 asymptomatic carriers have shown DNA aneuploidy and cell cycle arrest at cell cycle phase G0/G1 in CD4+ T cells. CD8+ T cells of HTLV-1 asymptomatic carriers also demonstrated DNA aneuploidy but without alteration in cell cycle. In ATL, CD4+ and CD8+ T cells present a higher number of cells in cell cycle S-phase and PTTG1 overexpression. These studies provide insight into malignant transformation of HTLV-1 asymptomatic carriers to ATL patients.
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Affiliation(s)
- Debora Levy
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), School of Medicine, Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
| | - Mari Cleia M R Ferreira
- Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Cadiele O Reichert
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), School of Medicine, Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
| | - Lis Vilela de Almeida
- Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Graciela Brocardo
- Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Luis Alberto P C Lage
- Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Hebert F Culler
- Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Youko Nukui
- Pro-Sangue Foundation, Department of Hematology, Hemotherapy and Cell Therapy, School of Medicine, University of São Paulo, São Paulo, Brazil
| | - Sergio P Bydlowski
- Lipids, Oxidation and Cell Biology Team, Laboratory of Immunology (LIM19), School of Medicine, Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
| | - Juliana Pereira
- Laboratory of Medical Investigation on Pathogenesis and Targeted Therapy in Onco-Immuno-Hematology (LIM-31), School of Medicine, University of São Paulo, São Paulo, Brazil
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6
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Tavakolian S, Goudarzi H, Faghihloo E. Cyclin-dependent kinases and CDK inhibitors in virus-associated cancers. Infect Agent Cancer 2020; 15:27. [PMID: 32377232 PMCID: PMC7195796 DOI: 10.1186/s13027-020-00295-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/24/2020] [Indexed: 12/11/2022] Open
Abstract
The role of several risk factors, such as pollution, consumption of alcohol, age, sex and obesity in cancer progression is undeniable. Human malignancies are mainly characterized by deregulation of cyclin-dependent kinases (CDK) and cyclin inhibitor kinases (CIK) activities. Viruses express some onco-proteins which could interfere with CDK and CIKs function, and induce some signals to replicate their genome into host's cells. By reviewing some studies about the function of CDK and CIKs in cells infected with oncoviruses, such as HPV, HTLV, HERV, EBV, KSHV, HBV and HCV, we reviewed the mechanisms of different onco-proteins which could deregulate the cell cycle proteins.
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Affiliation(s)
- Shaian Tavakolian
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Goudarzi
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ebrahim Faghihloo
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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7
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Moles R, Sarkis S, Galli V, Omsland M, Purcell DFJ, Yurick D, Khoury G, Pise-Masison CA, Franchini G. p30 protein: a critical regulator of HTLV-1 viral latency and host immunity. Retrovirology 2019; 16:42. [PMID: 31852501 PMCID: PMC6921414 DOI: 10.1186/s12977-019-0501-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/29/2019] [Indexed: 12/24/2022] Open
Abstract
The extraordinarily high prevalence of HTLV-1 subtype C (HTLV-1C) in some isolated indigenous communities in Oceania and the severity of the health conditions associated with the virus impress the great need for basic and translational research to prevent and treat HTLV-1 infection. The genome of the virus’s most common subtype, HTLV-1A, encodes structural, enzymatic, and regulatory proteins that contribute to viral persistence and pathogenesis. Among these is the p30 protein encoded by the doubly spliced Tax-orf II mRNA, a nuclear/nucleolar protein with both transcriptional and post-transcriptional activity. The p30 protein inhibits the productive replication cycle via nuclear retention of the mRNA that encodes for both the viral transcriptional trans-activator Tax, and the Rex proteins that regulate the transport of incompletely spliced viral mRNA to the cytoplasm. In myeloid cells, p30 inhibits the PU-1 transcription factor that regulates interferon expression and is a critical mediator of innate and adaptive immunity. Furthermore, p30 alters gene expression, cell cycle progression, and DNA damage responses in T-cells, raising the hypothesis that p30 may directly contribute to T cell transformation. By fine-tuning viral expression while also inhibiting host innate responses, p30 is likely essential for viral infection and persistence. This concept is supported by the finding that macaques, a natural host for the closely genetically related simian T-cell leukemia virus 1 (STLV-1), exposed to an HTLV-1 knockout for p30 expression by a single point mutation do not became infected unless reversion and selection of the wild type HTLV-1 genotype occurs. All together, these data suggest that inhibition of p30 may help to curb and eventually eradicate viral infection by exposing infected cells to an effective host immune response.
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Affiliation(s)
- Ramona Moles
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Sarkis Sarkis
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Veronica Galli
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maria Omsland
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Damian F J Purcell
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, VIC, Australia
| | - David Yurick
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, VIC, Australia
| | - Georges Khoury
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Parkville, VIC, Australia
| | - Cynthia A Pise-Masison
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Genoveffa Franchini
- Animal Models and Retroviral Vaccines Section, Vaccine Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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8
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Harrod R. Silencers of HTLV-1 and HTLV-2: the pX-encoded latency-maintenance factors. Retrovirology 2019; 16:25. [PMID: 31492165 PMCID: PMC6731619 DOI: 10.1186/s12977-019-0487-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 08/30/2019] [Indexed: 11/10/2022] Open
Abstract
Of the members of the primate T cell lymphotropic virus (PTLV) family, only the human T-cell leukemia virus type-1 (HTLV-1) causes disease in humans—as the etiological agent of adult T-cell leukemia/lymphoma (ATLL), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other auto-inflammatory disorders. Despite having significant genomic organizational and structural similarities, the closely related human T-cell lymphotropic virus type-2 (HTLV-2) is considered apathogenic and has been linked with benign lymphoproliferation and mild neurological symptoms in certain infected patients. The silencing of proviral gene expression and maintenance of latency are central for the establishment of persistent infections in vivo. The conserved pX sequences of HTLV-1 and HTLV-2 encode several ancillary factors which have been shown to negatively regulate proviral gene expression, while simultaneously activating host cellular proliferative and pro-survival pathways. In particular, the ORF-II proteins, HTLV-1 p30II and HTLV-2 p28II, suppress Tax-dependent transactivation from the viral promoter—whereas p30II also inhibits PU.1-mediated inflammatory-signaling, differentially augments the expression of p53-regulated metabolic/pro-survival genes, and induces lymphoproliferation which could promote mitotic proviral replication. The ubiquitinated form of the HTLV-1 p13II protein localizes to nuclear speckles and interferes with recruitment of the p300 coactivator by the viral transactivator Tax. Further, the antisense-encoded HTLV-1 HBZ and HTLV-2 APH-2 proteins and mRNAs negatively regulate Tax-dependent proviral gene expression and activate inflammatory signaling associated with enhanced T-cell lymphoproliferation. This review will summarize our current understanding of the pX latency-maintenance factors of HTLV-1 and HTLV-2 and discuss how these products may contribute to the differences in pathogenicity between the human PTLVs.
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Affiliation(s)
- 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, USA.
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9
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Martinez MP, Al-Saleem J, Green PL. Comparative virology of HTLV-1 and HTLV-2. Retrovirology 2019; 16:21. [PMID: 31391116 PMCID: PMC6686503 DOI: 10.1186/s12977-019-0483-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 08/01/2019] [Indexed: 12/22/2022] Open
Abstract
Human T cell leukemia virus type 1 (HTLV-1) was the first discovered human retrovirus and the etiologic agent of adult T-cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. Shortly after the discovery of HTLV-1, human T-cell leukemia virus type 2 (HTLV-2) was isolated from a patient with hairy cell leukemia. Despite possession of similar structural features to HTLV-1, HTLV-2 has not been definitively associated with lymphoproliferative disease. Since their discovery, studies have been performed with the goal of highlighting the differences between HTLV-1 and HTLV-2. A better understanding of these differences will shed light on the specific pathogenic mechanisms of HTLV-1 and lead to novel therapeutic targets. This review will compare and contrast the two oldest human retroviruses with regards to epidemiology, genomic structure, gene products, and pathobiology.
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Affiliation(s)
- Michael P Martinez
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, USA.,Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Jacob Al-Saleem
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, USA.,Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA
| | - Patrick L Green
- Center for Retrovirus Research, The Ohio State University, Columbus, OH, USA. .,Department of Veterinary Biosciences, The Ohio State University, Columbus, OH, USA. .,Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.
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10
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Namdev P, Lyngdoh DL, Dar HY, Chaurasiya SK, Srivastava R, Tripathi T, Anupam R. Intrinsically Disordered Human T Lymphotropic Virus Type 1 p30 Protein: Experimental and Computational Evidence. AIDS Res Hum Retroviruses 2019; 35:477-487. [PMID: 30618266 DOI: 10.1089/aid.2018.0196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Human T lymphotropic virus type 1 (HTLV-1) causes adult T cell leukemia and lymphoma and other neuroinflammatory diseases. The pX region of HTLV-1 genome encodes an accessory protein p30 that is required for viral persistence and spread in the host. p30 regulates viral gene expression at the transcription level by competing with Tax for p300 binding and at posttranscriptional level by nuclear retention of tax/rex messenger RNA (mRNA). In addition, p30 modulates the host cellular environment by binding to various host proteins such as ATM, REGγ, and PRMT5. However, the low expression levels of p30 has been a major hurdle in studying its structure-function relationship in the context of HTLV-1 pathobiology, which is most likely due to its intrinsically disordered nature. To investigate the unstable nature of p30, flow cytometric analysis of p30-GFP fusion protein expressed in Escherichia coli was conducted and bioinformatics analysis of p30 was performed. The bacterial cells were green fluorescent protein (GFP) positive, indicating that p30-GFP was in the soluble fraction. Induction, particularly at higher temperature, reduced the expression of p30-GFP. Moreover, p30-GFP was detected exclusively in insoluble fraction upon cell lysis, suggesting its unstable and disordered nature. The bioinformatics analysis of p30 protein sequence and amino acid content revealed that p30 has highly disordered regions from amino acids 75-155 and 197-241. Furthermore, p30 has regions for macromolecular interactions that could stabilize it and these regions coincide with the unstable regions. Collectively, the study indicates that HTLV-1 p30 is an intrinsically disordered protein.
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Affiliation(s)
- Priyanka Namdev
- Department of Biotechnology, Dr. Harisingh Gour University, Sagar, India
| | - Denzelle Lee Lyngdoh
- Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North Eastern Hill University, Shillong, India
| | - Hamid Y. Dar
- Department of Zoology, Dr. Harisingh Gour University, Sagar, India
| | - Shivendra K. Chaurasiya
- Host-Pathogen Interaction and Signal Transduction Laboratory, Department of Microbiology, Dr. Harisingh Gour University, Sagar, India
| | | | - Timir Tripathi
- Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North Eastern Hill University, Shillong, India
| | - Rajaneesh Anupam
- Department of Biotechnology, Dr. Harisingh Gour University, Sagar, India
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11
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Fan Y, Sanyal S, Bruzzone R. Breaking Bad: How Viruses Subvert the Cell Cycle. Front Cell Infect Microbiol 2018; 8:396. [PMID: 30510918 PMCID: PMC6252338 DOI: 10.3389/fcimb.2018.00396] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 10/22/2018] [Indexed: 01/10/2023] Open
Abstract
Interactions between the host and viruses during the course of their co-evolution have not only shaped cellular function and the immune system, but also the counter measures employed by viruses. Relatively small genomes and high replication rates allow viruses to accumulate mutations and continuously present the host with new challenges. It is therefore, no surprise that they either escape detection or modulate host physiology, often by redirecting normal cellular pathways to their own advantage. Viruses utilize a diverse array of strategies and molecular targets to subvert host cellular processes, while evading detection. These include cell-cycle regulation, major histocompatibility complex-restricted antigen presentation, intracellular protein transport, apoptosis, cytokine-mediated signaling, and humoral immune responses. Moreover, viruses routinely manipulate the host cell cycle to create a favorable environment for replication, largely by deregulating cell cycle checkpoints. This review focuses on our current understanding of the molecular aspects of cell cycle regulation that are often targeted by viruses. Further study of their interactions should provide fundamental insights into cell cycle regulation and improve our ability to exploit these viruses.
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Affiliation(s)
- Ying Fan
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Sumana Sanyal
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,LKS Faculty of Medicine, School of Biomedical Sciences, The University of Hong Kong, Hong Kong, Hong Kong
| | - Roberto Bruzzone
- HKU-Pasteur Research Pole, LKS Faculty of Medicine, School of Public Health, The University of Hong Kong, Hong Kong, Hong Kong.,Department of Cell Biology and Infection, Institut Pasteur, Paris, France
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12
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Liu Y, Qi H, E M, Shi P, Zhang Q, Li S, Wang Y, Cao Y, Chen Y, Ba L, Gao J, Huang W, Sun H. Transient receptor potential vanilloid-3 (TRPV3) activation plays a central role in cardiac fibrosis induced by pressure overload in rats via TGF-β1 pathway. Naunyn Schmiedebergs Arch Pharmacol 2017; 391:131-143. [DOI: 10.1007/s00210-017-1443-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2017] [Accepted: 11/27/2017] [Indexed: 01/01/2023]
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13
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Nicot C. HTLV-I Tax-Mediated Inactivation of Cell Cycle Checkpoints and DNA Repair Pathways Contribute to Cellular Transformation: "A Random Mutagenesis Model". ACTA ACUST UNITED AC 2015; 2. [PMID: 26835512 DOI: 10.13188/2377-9292.1000009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To achieve cellular transformation, most oncogenic retroviruses use transduction by proto-oncogene capture or insertional mutagenesis, whereby provirus integration disrupts expression of tumor suppressors or proto-oncogenes. In contrast, the Human T-cell leukemia virus type 1 (HTLV-I) has been classified in a separate class referred to as "transactivating retroviruses". Current views suggest that the viral encoded Tax protein transactivates expression of cellular genes leading to deregulated growth and transformation. However, if Tax-mediated transactivation was indeed sufficient for cellular transformation, a fairly high frequency of infected cells would eventually become transformed. In contrast, the frequency of transformation by HTLV-I is very low, likely less than 5%. This review will discuss the current understanding and recent discoveries highlighting critical functions of Tax in cellular transformation. HTLV-I Tax carries out essential functions in order to override cell cycle checkpoints and deregulate cellular division. In addition, Tax expression is associated with increased DNA damage and genome instability. Since Tax can inhibit multiple DNA repair pathways and stimulate unfaithful DNA repair or bypass checkpoints, these processes allow accumulation of genetic mutations in the host genome. Given this, a "Random Mutagenesis" transformation model seems more suitable to characterize the oncogenic activities of HTLV-I.
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Affiliation(s)
- Christophe Nicot
- Department of Pathology and Laboratory Medicine, Center for Viral Oncology, University of Kansas Medical Center, USA
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14
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Bai XT, Nicot C. miR-28-3p is a cellular restriction factor that inhibits human T cell leukemia virus, type 1 (HTLV-1) replication and virus infection. J Biol Chem 2015; 290:5381-90. [PMID: 25568327 DOI: 10.1074/jbc.m114.626325] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human T cell leukemia virus, type 1 (HTLV-1) replication and spread are controlled by different viral and cellular factors. Although several anti-HIV cellular microRNAs have been described, such a regulation for HTLV-1 has not been reported. In this study, we found that miR-28-3p inhibits HTLV-1 virus expression and its replication by targeting a specific site within the genomic gag/pol viral mRNA. Because miR-28-3p is highly expressed in resting T cells, which are resistant to HTLV-1 infection, we investigated a potential protective role of miR-28-3p against de novo HTLV-1 infection. To this end, we developed a new sensitive and quantitative assay on the basis of the detection of products of reverse transcription. We demonstrate that miR-28-3p does not prevent virus receptor interaction or virus entry but, instead, induces a post-entry block at the reverse transcription level. In addition, we found that HTLV-1, subtype 1A isolates corresponding to the Japanese strain ATK-1 present a natural, single-nucleotide polymorphism within the miR-28-3p target site. As a result of this polymorphism, the ATK-1 virus sequence was not inhibited by miR-28. Interestingly, genetic studies on the transmission of the virus has shown that the ATK-1 strain, which carries a Thr-to-Cys transition mutation, is transmitted efficiently between spouses, suggesting that miR-28 may play an important role in HTLV-1 transmission.
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Affiliation(s)
- Xue Tao Bai
- From the University of Kansas Medical Center, Department of Pathology and Laboratory Medicine and Center for Viral Oncology, Kansas City, Kansas 66160
| | - Christophe Nicot
- From the University of Kansas Medical Center, Department of Pathology and Laboratory Medicine and Center for Viral Oncology, Kansas City, Kansas 66160
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15
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Yang Y, Ma B, Li L, Jin Y, Ben W, Zhang D, Jiang K, Feng S, Huang L, Zheng J. CDK2 and CDK4 play important roles in promoting the proliferation of SKOV3 ovarian carcinoma cells induced by tumor-associated macrophages. Oncol Rep 2014; 31:2759-68. [PMID: 24700371 DOI: 10.3892/or.2014.3127] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/13/2014] [Indexed: 11/06/2022] Open
Abstract
A large quantity of M2-polarized tumor-associated macrophages (TAMs) is present in the tissue, ascitic fluid and peritoneum of ovarian cancer patients. A thorough understanding of the roles of M2-TAM in the development of ovarian cancer may provide new insight into the treatment of this disease. The rapid advancement of omics techniques presents a great challenge to biologists to extract meaningful biological information from vast pools of data. In the present study, using microarray method, we identified 996 genes in SKOV3 ovarian carcinoma cells that underwent expression level changes under the influence of TAMs. Subsequently, based on the protein-protein interactions network and the differentially expressed genes, a network showing the influence of TAMs on SKOV3 cells was constructed. The resulting network was analyzed with CFinder software and four modules were found; these modules were further analyzed using David software to perform functional annotations. It was found that module I was mainly related to tumorigenesis and cell cycle. Hence, 31 genes in module I were analyzed with Cytoscape software to generate a gene-function network, which revealed that four gene proteins (E2F1, RB1, CDK2 and CDK4) were functional. Based on literature review, we postulated that CDK2 and CDK4 were key players in the network. In the subsequent molecular experiments, western blot analysis and kinase activity detection demonstrated that TAMs can significantly boost the expression levels and activities of CDK2 and CDK4 in SKOV3 cells. With 3H-TdR incorporation and flow cytometry assay, the proliferation and cell cycle distribution of SKOV3 cells were detected in the absence or presence of CDK2 and CDK4 inhibitors and the results confirmed that the two kinases played a key role in TAM cells enhancing SKOV3 cell proliferation by promoting G0/G1 to S transition. In the present study, we identified the specific changes in the gene expression profile of SKOV3 cells under the influence of TAMs and explored a method for analyzing the gene expression profile data. The results may aid in the design of subsequent molecular experiments.
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Affiliation(s)
- Yang Yang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Biao Ma
- Department of General Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Ling Li
- School of Computing, University of Kent, Canterbury, Kent, CT2 7NF, UK
| | - Ye Jin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Wei Ben
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Dandan Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Keping Jiang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Shujun Feng
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Lu Huang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Jianhua Zheng
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
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16
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Abstract
To replicate their genomes in cells and generate new progeny, viruses typically require factors provided by the cells that they have infected. Subversion of the cellular machinery that controls replication of the infected host cell is a common activity of many viruses. Viruses employ different strategies to deregulate cell cycle checkpoint controls and modulate cell proliferation pathways. A number of DNA and RNA viruses encode proteins that target critical cell cycle regulators to achieve cellular conditions that are beneficial for viral replication. Many DNA viruses induce quiescent cells to enter the cell cycle; this is thought to increase pools of deoxynucleotides and thus, facilitate viral replication. In contrast, some viruses can arrest cells in a particular phase of the cell cycle that is favorable for replication of the specific virus. Cell cycle arrest may inhibit early cell death of infected cells, allow the cells to evade immune defenses, or help promote virus assembly. Although beneficial for the viral life cycle, virus-mediated alterations in normal cell cycle control mechanisms could have detrimental effects on cellular physiology and may ultimately contribute to pathologies associated with the viral infection, including cell transformation and cancer progression and maintenance. In this chapter, we summarize various strategies employed by DNA and RNA viruses to modulate the replication cycle of the virus-infected cell. When known, we describe how these virus-associated effects influence replication of the virus and contribute to diseases associated with infection by that specific virus.
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Affiliation(s)
- Eishi Noguchi
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania USA
| | - Mariana C. Gadaleta
- Dept of Biochemistry & Molecular Biology, Drexel University College of Medicine, Philadelphia, USA
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17
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Anupam R, Doueiri R, Green PL. The need to accessorize: molecular roles of HTLV-1 p30 and HTLV-2 p28 accessory proteins in the viral life cycle. Front Microbiol 2013; 4:275. [PMID: 24062732 PMCID: PMC3774995 DOI: 10.3389/fmicb.2013.00275] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/24/2013] [Indexed: 11/25/2022] Open
Abstract
Extensive studies of human T-cell leukemia virus (HTLV)-1 and HTLV-2 over the last three decades have provided detailed knowledge on viral transformation, host–viral interactions and pathogenesis. HTLV-1 is the etiological agent of adult T cell leukemia and multiple neurodegenerative and inflammatory diseases while HTLV-2 disease association remains elusive, with few infected individuals displaying neurodegenerative diseases similar to HTLV-1. The HTLV group of oncoretroviruses has a genome that encodes structural and enzymatic proteins Gag, Pro, and Env, regulatory proteins Tax and Rex, and several accessory proteins from the pX region. Of these proteins, HTLV-1 p30 and HTLV-2 p28 are encoded by the open reading frame II of the pX region. Like most other accessory proteins, p30 and p28 are dispensable for in vitro viral replication and transformation but are required for efficient viral replication and persistence in vivo. Both p30 and p28 regulate viral gene expression at the post-transcriptional level whereas p30 can also function at the transcriptional level. Recently, several reports have implicated p30 and p28 in multiple cellular processes, which provide novel insight into HTLV spread and survival and ultimately pathogenesis. In this review we summarize and compare what is known about p30 and p28, highlighting their roles in viral replication and viral pathogenesis.
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Affiliation(s)
- Rajaneesh Anupam
- Center for Retrovirus Research, The Ohio State University Columbus, OH, USA ; Department of Veterinary Biosciences, The Ohio State University Columbus, OH, USA
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18
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Liu Q, Liu X, Gao J, Shi X, Hu X, Wang S, Luo Y. Overexpression of DOC-1R inhibits cell cycle G1/S transition by repressing CDK2 expression and activation. Int J Biol Sci 2013; 9:541-9. [PMID: 23781148 PMCID: PMC3683939 DOI: 10.7150/ijbs.5763] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2012] [Accepted: 05/31/2013] [Indexed: 01/01/2023] Open
Abstract
DOC-1R (deleted in oral cancer-1 related) is a novel putative tumor suppressor. This study investigated DOC-1R antitumor activity and the underlying molecular mechanisms. Cell phenotypes were assessed using flow cytometry, BrdU incorporation and CDK2 kinase assays in DOC-1R overexpressing HeLa cells. In addition, RT-PCR and Western blot assays were used to detect underlying molecular changes in these cells. The interaction between DOC-1R and CDK2 proteins was assayed by GST pull-down and immunoprecipitation-Western blot assays. The data showed that DOC-1R overexpression inhibited G1/S phase transition, DNA replication and suppressed CDK2 activity. Molecularly, DOC-1R inhibited CDK2 expression at the mRNA and protein levels, and there were decreased levels of G1-phase cyclins (cyclin D1 and E) and elevated levels of p21, p27, and p53 proteins. Meanwhile, DOC-1R associated with CDK2 and inhibited CDK2 activation by obstructing its association with cyclin E and A. In conclusion, the antitumor effects of DOC-1R may be mediated by negatively regulating G1 phase progression and G1/S transition through inhibiting CDK2 expression and activation.
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Affiliation(s)
| | | | | | | | | | | | - Yang Luo
- The Research Center for Medical Genomics, MOH Key Laboratory of Cell Biology and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China
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19
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Bai XT, Nicot C. Overview on HTLV-1 p12, p8, p30, p13: accomplices in persistent infection and viral pathogenesis. Front Microbiol 2012; 3:400. [PMID: 23248621 PMCID: PMC3518833 DOI: 10.3389/fmicb.2012.00400] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Indexed: 12/29/2022] Open
Abstract
The human T-lymphotropic virus type-1 (HTLV-1) is etiologically linked to adult T cell leukemia/lymphoma and tropical spastic paraparesis/HTLV-1-associated myelopathy. While the role of Tax and Rex in viral replication and pathogenesis has been extensively studied, recent evidence suggests that additional viral proteins are essential for the virus life cycle in vivo. In this review, we will summarize possible molecular mechanisms evoked in the literature to explain how p12, p8, p30, and p13 facilitate persistent viral infection of the host. We will explore several stratagems used by HTLV-1 accessory genes to escape immune surveillance, to establish latency, and to deregulate cell cycle and apoptosis to participate in virus-mediated cellular transformation.
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Affiliation(s)
- Xue Tao Bai
- Department of Pathology and Laboratory Medicine, University of Kansas Medical Center Kansas City, KS, USA
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20
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Abstract
UNLABELLED The establishment of a latent reservoir by human tumor viruses is a vital step in initiating cellular transformation and represents a major shortcoming to current therapeutic strategies and the ability to eradicate virus-infected cells. Human T-cell leukemia virus type 1 (HTLV-1) establishes a lifelong infection and is linked to adult T-cell leukemia lymphoma (ATLL). Here, we demonstrate that HTLV-1 p30 recruits the cellular proteasome activator PA28γ onto the viral tax/rex mRNA to prevent its nuclear export and suppress virus replication. Interaction of p30 with a PA28γ retaining fully functional proteasome activity is required for p30's ability to repress HTLV-1. Consistently, HTLV-1 molecular clones replicate better and produce more virus particles in PA28γ-deficient cells. These results define a unique and novel role for the cellular factor PA28γ in the control of nuclear RNA trafficking and HTLV-1–induced latency. Importantly, knockdown of PA28γ expression in ATLL cells latently infected with HTLV-1 reactivates expression of viral tax/rex RNA and the Tax protein. Because Tax is the most immunogenic viral antigen and triggers strong CTL responses, our results suggest that PA28γ-targeted therapy may reactivate virus expression from latently infected cells and allow their eradication from the host. KEY POINTS PA28γ acts as a co-repressor of HTLV-1 p30 to suppress virus replication and is required for the maintenance of viral latency. HTLV-1 has evolved a unique function mediated by its posttranscriptional repressor p30, which is not found in HTLV-2.
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21
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Bidoia C. Human T-lymphotropic virus proteins and post-translational modification pathways. World J Virol 2012; 1:115-30. [PMID: 24175216 PMCID: PMC3782272 DOI: 10.5501/wjv.v1.i4.115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 06/04/2012] [Accepted: 07/13/2012] [Indexed: 02/05/2023] Open
Abstract
Cell life from the cell cycle to the signaling transduction and response to stimuli is finely tuned by protein post-translational modifications (PTMs). PTMs alter the conformation, the stability, the localization, and hence the pattern of interactions of the targeted protein. Cell pathways involve the activation of enzymes, like kinases, ligases and transferases, that, once activated, act on many proteins simultaneously, altering the state of the cell and triggering the processes they are involved in. Viruses enter a balanced system and hijack the cell, exploiting the potential of PTMs either to activate viral encoded proteins or to alter cellular pathways, with the ultimate consequence to perpetuate through their replication. Human T-lymphotropic virus type 1 (HTLV-1) is known to be highly oncogenic and associates with adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy/tropical spastic paraparesis and other inflammatory pathological conditions. HTLV-1 protein activity is controlled by PTMs and, in turn, viral activity is associated with the modulation of cellular pathways based on PTMs. More knowledge is acquired about the PTMs involved in the activation of its proteins, like Tax, Rex, p12, p13, p30, HTLV-I basic leucine zipper factor and Gag. However, more has to be understood at the biochemical level in order to counteract the associated fatal outcomes. This review will focus on known PTMs that directly modify HTLV-1 components and on enzymes whose activity is modulated by viral proteins.
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Affiliation(s)
- Carlo Bidoia
- Carlo Bidoia, Centre for Research in Infectious Diseases, School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4, Ireland
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22
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Doueiri R, Anupam R, Kvaratskhelia M, Green KB, Lairmore MD, Green PL. Comparative host protein interactions with HTLV-1 p30 and HTLV-2 p28: insights into difference in pathobiology of human retroviruses. Retrovirology 2012; 9:64. [PMID: 22876852 PMCID: PMC3464894 DOI: 10.1186/1742-4690-9-64] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 07/11/2012] [Indexed: 02/02/2023] Open
Abstract
Background Human T lymphotropic virus type-1 (HTLV-1) and type 2 (HTLV-2) are closely related human retroviruses, but have unique disease associations. HTLV-1 is the causative agent of an aggressive T-cell leukemia known as adult T-cell leukemia (ATL), HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other inflammatory diseases. HTLV-2 infection has not been clearly associated with any disease condition. Although both viruses can transform T cells in vitro, the HTLV-1 provirus is mainly detected in CD4+ T cells whereas HTLV-2 is mainly detected in CD8+ T cells of infected individuals. HTLV-1 and HTLV-2 encode accessory proteins p30 and p28, respectively, which share partial amino acid homology and are required for viral persistence in vivo. The goal of this study was to identify host proteins interacting with p30 and p28 in order to understand their role in pathogenesis. Results Affinity-tag purification coupled with mass spectrometric (MS) analyses revealed 42 and 22 potential interacting cellular partners of p30 and p28, respectively. Of these, only three cellular proteins, protein arginine methyltransferase 5 (PRMT5), hnRNP K and 60 S ribosomal protein L8 were detected in both p30 and p28 fractions. To validate the proteomic results, four interacting proteins were selected for further analyses using immunoblot assays. In full agreement with the MS analysis two cellular proteins REGγ and NEAF-interacting protein 30 (NIP30) selectively interacted with p30 and not with p28; heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) bound to p28 and not to p30; and PRMT5 interacted with both p30 and p28. Further studies demonstrated that reduced levels of PRMT5 resulted in decreased HTLV-2 viral gene expression whereas the viral gene expression of HTLV-1 was unchanged. Conclusion The comparisons of p30 and p28 host protein interaction proteome showed striking differences with some degree of overlap. PRMT5, one of the host proteins that interacted with both p30 and p28 differentially affected HTLV-1 and HTLV-2 viral gene expression suggesting that PRMT5 is involved at different stages of HTLV-1 and HTLV-2 biology. These findings suggest that distinct host protein interaction profiles of p30 and p28 could, in part, be responsible for differences in HTLV-1 and HTLV-2 pathobiology. This study provides new avenues of investigation into mechanisms of viral infection, tropism and persistence.
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Affiliation(s)
- Rami Doueiri
- Center for Retrovirus Research, The Ohio State University, Columbus, OH 43210, USA
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The transcription profile of Tax-3 is more similar to Tax-1 than Tax-2: insights into HTLV-3 potential leukemogenic properties. PLoS One 2012; 7:e41003. [PMID: 22911729 PMCID: PMC3401231 DOI: 10.1371/journal.pone.0041003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 06/15/2012] [Indexed: 11/19/2022] Open
Abstract
Human T-cell Lymphotropic Viruses type 1 (HTLV-1) is the etiological agent of Adult T-cell Leukemia/Lymphoma. Although associated with lymphocytosis, HTLV-2 infection is not associated with any malignant hematological disease. Similarly, no infection-related symptom has been detected in HTLV-3-infected individuals studied so far. Differences in individual Tax transcriptional activity might account for these distinct physiopathological outcomes. Tax-1 and Tax-3 possess a PDZ binding motif in their sequence. Interestingly, this motif, which is critical for Tax-1 transforming activity, is absent from Tax-2. We used the DNA microarray technology to analyze and compare the global gene expression profiles of different T- and non T-cell types expressing Tax-1, Tax-2 or Tax-3 viral transactivators. In a T-cell line, this analysis allowed us to identify 48 genes whose expression is commonly affected by all Tax proteins and are hence characteristic of the HTLV infection, independently of the virus type. Importantly, we also identified a subset of genes (n = 70) which are specifically up-regulated by Tax-1 and Tax-3, while Tax-1 and Tax-2 shared only 1 gene and Tax-2 and Tax-3 shared 8 genes. These results demonstrate that Tax-3 and Tax-1 are closely related in terms of cellular gene deregulation. Analysis of the molecular interactions existing between those Tax-1/Tax-3 deregulated genes then allowed us to highlight biological networks of genes characteristic of HTLV-1 and HTLV-3 infection. The majority of those up-regulated genes are functionally linked in biological processes characteristic of HTLV-1-infected T-cells expressing Tax such as regulation of transcription and apoptosis, activation of the NF-κB cascade, T-cell mediated immunity and induction of cell proliferation and differentiation. In conclusion, our results demonstrate for the first time that, in T- and non T-cells types, Tax-3 is a functional analogue of Tax-1 in terms of transcriptional activation and suggest that HTLV-3 might share pathogenic features with HTLV-1 in vivo.
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Nascimento R, Costa H, Parkhouse RME. Virus manipulation of cell cycle. PROTOPLASMA 2012; 249:519-528. [PMID: 21986922 DOI: 10.1007/s00709-011-0327-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 09/28/2011] [Indexed: 05/31/2023]
Abstract
Viruses depend on host cell resources for replication and access to those resources may be limited to a particular phase of the cell cycle. Thus manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment. For example, viruses capable of infecting nondividing cells induce S phase in order to activate the host DNA replication machinery and provide the nucleotide triphosphates necessary for viral DNA replication (Flemington in J Virol 75:4475-4481, 2001; Sullivan and Pipas in Microbiol Mol Biol Rev 66:179-202, 2002). Viruses have developed several strategies to subvert the cell cycle by association with cyclin and cyclin-dependent kinase complexes and molecules that regulate their activity. Viruses tend to act on cellular proteins involved in a network of interactions in a way that minimal protein-protein interactions lead to a major effect. The complex and interactive nature of intracellular signaling pathways controlling cell division affords many opportunities for virus manipulation strategies. Taking the maxim "Set a thief to catch a thief" as a counter strategy, however, provides us with the very same virus evasion strategies as "ready-made tools" for the development of novel antivirus therapeutics. The most obvious are attenuated virus vaccines with critical evasion genes deleted. Similarly, vaccines against viruses causing cancer are now being successfully developed. Finally, as viruses have been playing chess with our cell biology and immune responses for millions of years, the study of their evasion strategies will also undoubtedly reveal new control mechanisms and their corresponding cellular intracellular signaling pathways.
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Affiliation(s)
- R Nascimento
- Instituto Gulbenkian de Ciencia, Oeiras, Portugal.
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25
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Orf-I and orf-II-encoded proteins in HTLV-1 infection and persistence. Viruses 2011; 3:861-85. [PMID: 21994758 PMCID: PMC3185781 DOI: 10.3390/v3060861] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 05/25/2011] [Accepted: 05/26/2011] [Indexed: 01/10/2023] Open
Abstract
The 3′ end of the human T-cell leukemia/lymphoma virus type-1 (HTLV-1) genome contains four overlapping open reading frames (ORF) that encode regulatory proteins. Here, we review current knowledge of HTLV-1 orf-I and orf-II protein products. Singly spliced mRNA from orf-I encodes p12, which can be proteolytically cleaved to generate p8, while differential splicing of mRNA from orf-II results in production of p13 and p30. These proteins have been demonstrated to modulate transcription, apoptosis, host cell activation and proliferation, virus infectivity and transmission, and host immune responses. Though these proteins are not essential for virus replication in vitro, p8, p12, p13, and p30 have an important role in the establishment and maintenance of HTLV-1 infection in vivo.
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26
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Human T-lymphotropic type 1 virus p30 inhibits homologous recombination and favors unfaithful DNA repair. Blood 2011; 117:5897-906. [PMID: 21427292 DOI: 10.1182/blood-2010-08-304600] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Whereas oncogenic retroviruses are common in animals, human T-lymphotropic virus 1 (HTLV-1) is the only transmissible retrovirus associated with cancer in humans and is etiologically linked to adult T-cell leukemia. The leukemogenesis process is still largely unknown, but relies on extended survival and clonal expansion of infected cells, which in turn accumulate genetic defects. A common feature of human tumor viruses is their ability to stimulate proliferation and survival of infected pretumoral cells and then hide by establishing latency in cells that have acquired a transformed phenotype. Whereas disruption of the DNA repair is one of the major processes responsible for the accumulation of genomic abnormalities and carcinogenesis, the absence of DNA repair also poses the threat of cell-cycle arrest or apoptosis of virus-infected cells. This study describes how the HTLV-1 p30 viral protein inhibits conservative homologous recombination (HR) DNA repair by targeting the MRE11/RAD50/NBS1 complex and favors the error-prone nonhomologous-end-joining (NHEJ) DNA-repair pathway instead. As a result, HTLV-1 p30 may facilitate the accumulation of mutations in the host genome and the cumulative risk of transformation. Our results provide new insights into how human tumor viruses may manipulate cellular DNA-damage responses to promote cancer.
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