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Chen G, Yu D, Yang Y, Li X, Wang X, Sun D, Lu Y, Ke R, Zhang G, Cui J, Feng S. Adaptive expansion of ERVK solo-LTRs is associated with Passeriformes speciation events. Nat Commun 2024; 15:3151. [PMID: 38605055 PMCID: PMC11009239 DOI: 10.1038/s41467-024-47501-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
Endogenous retroviruses (ERVs) are ancient retroviral remnants integrated in host genomes, and commonly deleted through unequal homologous recombination, leaving solitary long terminal repeats (solo-LTRs). This study, analysing the genomes of 362 bird species and their reptilian and mammalian outgroups, reveals an unusually higher level of solo-LTRs formation in birds, indicating evolutionary forces might have purged ERVs during evolution. Strikingly in the order Passeriformes, and especially the parvorder Passerida, endogenous retrovirus K (ERVK) solo-LTRs showed bursts of formation and recurrent accumulations coinciding with speciation events over past 22 million years. Moreover, our results indicate that the ongoing expansion of ERVK solo-LTRs in these bird species, marked by high transcriptional activity of ERVK retroviral genes in reproductive organs, caused variation of solo-LTRs between individual zebra finches. We experimentally demonstrated that cis-regulatory activity of recently evolved ERVK solo-LTRs may significantly increase the expression level of ITGA2 in the brain of zebra finches compared to chickens. These findings suggest that ERVK solo-LTRs expansion may introduce novel genomic sequences acting as cis-regulatory elements and contribute to adaptive evolution. Overall, our results underscore that the residual sequences of ancient retroviruses could influence the adaptive diversification of species by regulating host gene expression.
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Affiliation(s)
- Guangji Chen
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China
- BGI Research, Wuhan, China
| | - Dan Yu
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China
- Center for Genomic Research, International Institutes of Medicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yu Yang
- School of Medicine, Huaqiao University, Xiamen, Fujian, 361021, China
| | - Xiang Li
- CAS Key Laboratory of Molecular Virology & Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Xiaojing Wang
- CAS Key Laboratory of Molecular Virology & Immunology, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Shanghai, China
| | - Danyang Sun
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China
- Center for Genomic Research, International Institutes of Medicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Yanlin Lu
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China
- Center for Genomic Research, International Institutes of Medicine, The Fourth Affiliated Hospital, Zhejiang University School of Medicine, Yiwu, Zhejiang, China
| | - Rongqin Ke
- School of Medicine, Huaqiao University, Xiamen, Fujian, 361021, China
| | - Guojie Zhang
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China
- Innovation Center of Yangtze River Delta, Zhejiang University, Jiashan, China
| | - Jie Cui
- Department of Infectious Diseases, National Medical Center for Infectious Diseases, Huashan Hospital, Institute of Infection and Health Research, Fudan University, Shanghai, China.
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, China.
- Shanghai Sci-Tech Inno Center for Infection & Immunity, Shanghai, 200052, China.
- Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, Huashan Hospital, Fudan University, Shanghai, China.
| | - Shaohong Feng
- Center for Evolutionary & Organismal Biology, Liangzhu Laboratory, Zhejiang University School of Medicine, Hangzhou, China.
- Innovation Center of Yangtze River Delta, Zhejiang University, Jiashan, China.
- Department of General Surgery of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China.
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2
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Coley AK, Lu C, Pankaj A, Emmett MJ, Lang ER, Song Y, Xu KH, Xu N, Patel BK, Chougule A, Nieman LT, Aryee MJ, Ferrone CR, Deshpande V, Franses JW, Ting DT. Dysregulated Repeat Element Viral-like Immune Response in Hepatocellular Carcinoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.04.570014. [PMID: 38105940 PMCID: PMC10723373 DOI: 10.1101/2023.12.04.570014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Purpose Dysregulation of viral-like repeat RNAs are a common feature across many malignancies that are linked with immunological response, but the characterization of these in hepatocellular carcinoma (HCC) is understudied. In this study, we performed RNA in situ hybridization (RNA-ISH) of different repeat RNAs, immunohistochemistry (IHC) for immune cell subpopulations, and spatial transcriptomics to understand the relationship of HCC repeat expression, immune response, and clinical outcomes. Experimental Design RNA-ISH for LINE1, HERV-K, HERV-H, and HSATII repeats and IHC for T-cell, Treg, B-cell, macrophage, and immune checkpoint markers were performed on 43 resected HCC specimens. Spatial transcriptomics on tumor and vessel regions of interest was performed on 28 specimens from the same cohort. Results High HERV-K and high LINE1 expression were both associated with worse overall survival. There was a positive correlation between LINE1 expression and FOXP3 T-regulatory cells (r = 0.51 p < 0.001) as well as expression of the TIM3 immune checkpoint (r = 0.34, p = 0.03). Spatial transcriptomic profiling of HERV-K high and LINE-1 high tumors identified elevated expression of multiple genes previously associated with epithelial mesenchymal transition, cellular proliferation, and worse overall prognosis in HCC including SSX1, MAGEC2, and SPINK1. Conclusion Repeat RNAs may serve as useful prognostic biomarkers in HCC and may also serve as novel therapeutic targets. Additional study is needed to understand the mechanisms by which repeat RNAs impact HCC tumorigenesis.
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Affiliation(s)
- Avril K. Coley
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
- Department of Surgery, Massachusetts General Hospital Harvard Medical School; Boston, MA, USA
| | - Chenyue Lu
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
- Health Sciences and Technology Program; Cambridge, MA, USA
| | - Amaya Pankaj
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Matthew J. Emmett
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School; Boston, MA, USA
| | - Evan R. Lang
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Yuhui Song
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Katherine H. Xu
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Nova Xu
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Bidish K. Patel
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Abhijit Chougule
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Linda T. Nieman
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
| | - Martin J. Aryee
- Department of Biostatistics, Harvard T.H. Chan School of Public Health; Boston, MA, USA
- Department of Data Sciences, Dana-Farber Cancer Institute; Boston, MA, USA
- Broad Institute of Harvard and MIT; Cambridge, MA, USA
| | | | - Vikram Deshpande
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School; Boston, MA, USA
| | - Joseph W. Franses
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School; Boston, MA, USA
- Health Sciences and Technology Program; Cambridge, MA, USA
- Section of Hematology-Oncology, Department of Medicine, University of Chicago; Chicago, IL, USA
| | - David T. Ting
- Mass General Cancer Center, Harvard Medical School; Charlestown, MA, USA
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School; Boston, MA, USA
- Health Sciences and Technology Program; Cambridge, MA, USA
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3
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Costa B, Vale N. Exploring HERV-K (HML-2) Influence in Cancer and Prospects for Therapeutic Interventions. Int J Mol Sci 2023; 24:14631. [PMID: 37834078 PMCID: PMC10572383 DOI: 10.3390/ijms241914631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/19/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
This review investigates the intricate role of human endogenous retroviruses (HERVs) in cancer development and progression, explicitly focusing on HERV-K (HML-2). This paper sheds light on the latest research advancements and potential treatment strategies by examining the historical context of HERVs and their involvement in critical biological processes such as embryonic development, immune response, and disease progression. This review covers computational modeling for drug-target binding assessment, systems biology modeling for simulating HERV-K viral cargo dynamics, and using antiviral drugs to combat HERV-induced diseases. The findings presented in this review contribute to our understanding of HERV-mediated disease mechanisms and provide insights into future therapeutic approaches. They emphasize why HERV-K holds significant promise as a biomarker and a target.
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Affiliation(s)
- Bárbara Costa
- OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal
| | - Nuno Vale
- OncoPharma Research Group, Center for Health Technology and Services Research (CINTESIS), Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal;
- CINTESIS@RISE, Faculty of Medicine, University of Porto, Alameda Professor Hernâni Monteiro, 4200-319 Porto, Portugal
- Department of Community Medicine, Information and Health Decision Sciences (MEDCIDS), Faculty of Medicine, University of Porto, Rua Doutor Plácido da Costa, s/n, 4200-450 Porto, Portugal
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Wang D, Gomes MT, Mo Y, Prohaska CC, Zhang L, Chelvanambi S, Clauss MA, Zhang D, Machado RF, Gao M, Bai Y. Human Endogenous Retrovirus, SARS-CoV-2, and HIV Promote PAH via Inflammation and Growth Stimulation. Int J Mol Sci 2023; 24:7472. [PMID: 37108634 PMCID: PMC10138839 DOI: 10.3390/ijms24087472] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease characterized by the progressive elevation of pulmonary arterial pressures. It is becoming increasingly apparent that inflammation contributes to the pathogenesis and progression of PAH. Several viruses are known to cause PAH, such as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human endogenous retrovirus K(HERV-K), and human immunodeficiency virus (HIV), in part due to acute and chronic inflammation. In this review, we discuss the connections between HERV-K, HIV, SARS-CoV-2, and PAH, to stimulate research regarding new therapeutic options and provide new targets for the treatment of the disease.
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Affiliation(s)
- Desheng Wang
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Marta T. Gomes
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Yanfei Mo
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Clare C. Prohaska
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Lu Zhang
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Sarvesh Chelvanambi
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Matthias A. Clauss
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Dongfang Zhang
- Department of Pharmacognosy, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Roberto F. Machado
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Mingqi Gao
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Yang Bai
- Department of Clinical Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
- Division of Pulmonary, Critical Care, Sleep, and Occupational Medicine, Department of Medicine, Indiana University, Indianapolis, IN 46202, USA
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5
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Hosseiniporgham S, Sechi LA. Anti-HERV-K Drugs and Vaccines, Possible Therapies against Tumors. Vaccines (Basel) 2023; 11:vaccines11040751. [PMID: 37112663 PMCID: PMC10144246 DOI: 10.3390/vaccines11040751] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 03/20/2023] [Accepted: 03/21/2023] [Indexed: 03/31/2023] Open
Abstract
The footprint of human endogenous retroviruses (HERV), specifically HERV-K, has been found in malignancies, such as melanoma, teratocarcinoma, osteosarcoma, breast cancer, lymphoma, and ovary and prostate cancers. HERV-K is characterized as the most biologically active HERV due to possession of open reading frames (ORF) for all Gag, Pol, and Env genes, which enables it to be more infective and obstructive towards specific cell lines and other exogenous viruses, respectively. Some factors might contribute to carcinogenicity and at least one of them has been recognized in various tumors, including overexpression/methylation of long interspersed nuclear element 1 (LINE-1), HERV-K Gag, and Env genes themselves plus their transcripts and protein products, and HERV-K reverse transcriptase (RT). Therapies effective for HERV-K-associated tumors mostly target invasive autoimmune responses or growth of tumors through suppression of HERV-K Gag or Env protein and RT. To design new therapeutic options, more studies are needed to better understand whether HERV-K and its products (Gag/Env transcripts and HERV-K proteins/RT) are the initiators of tumor formation or just the disorder’s developers. Accordingly, this review aims to present evidence that highlights the association between HERV-K and tumorigenicity and introduces some of the available or potential therapies against HERV-K-induced tumors.
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6
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Kristensen MK, Christensen T. Regulation of the expression of human endogenous retroviruses: elements in fetal development and a possible role in the development of cancer and neurological diseases. APMIS 2021; 129:241-253. [PMID: 33683784 DOI: 10.1111/apm.13130] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/03/2021] [Indexed: 12/14/2022]
Abstract
Human endogenous retroviruses (HERVs) are remnants of ancient retroviral germline infections. Most HERV sequences are silenced in somatic cells, but interest is emerging on the involvement of HERV derived transcripts and proteins in human physiology and disease. A HERV-W encoded protein, syncytin-1, has been co-opted into fetal physiology, where it plays a role in trophoblast formation. Altered HERV transcription and expression of HERV derived proteins are associated with various cancer types and neurological diseases such as multiple sclerosis (MS). The implication of HERVs as potential mediators of both health and disease suggests important roles of regulatory mechanisms and alterations of these in physiological and pathological processes. The regulation of HERV sequences is mediated by a wide variety of mechanisms, and the focus of this review is on selected aspects of these, including epigenetic mechanisms such as CpG methylation and histone modifications of the HP1-H3K9me axis, viral transactivation events, and regulatory perspectives of transient stimuli in the microenvironment. Increasing knowledge of the regulation of HERV sequences will not only contribute to the understanding of complex pathogeneses, but also may pinpoint potential targets for better diagnosis and treatment in complex diseases as MS.
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7
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Sznarkowska A, Mikac S, Pilch M. MHC Class I Regulation: The Origin Perspective. Cancers (Basel) 2020; 12:cancers12051155. [PMID: 32375397 PMCID: PMC7281430 DOI: 10.3390/cancers12051155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/27/2020] [Accepted: 05/03/2020] [Indexed: 12/11/2022] Open
Abstract
Viral-derived elements and non-coding RNAs that build up “junk DNA” allow for flexible and context-dependent gene expression. They are extremely dense in the MHC region, accounting for flexible expression of the MHC I, II, and III genes and adjusting the level of immune response to the environmental stimuli. This review brings forward the viral-mediated aspects of the origin and evolution of adaptive immunity and aims to link this perspective with the MHC class I regulation. The complex regulatory network behind MHC expression is largely controlled by virus-derived elements, both as binding sites for immune transcription factors and as sources of regulatory non-coding RNAs. These regulatory RNAs are imbalanced in cancer and associate with different tumor types, making them promising targets for diagnostic and therapeutic interventions.
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8
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Chan SM, Sapir T, Park SS, Rual JF, Contreras-Galindo R, Reiner O, Markovitz DM. The HERV-K accessory protein Np9 controls viability and migration of teratocarcinoma cells. PLoS One 2019; 14:e0212970. [PMID: 30818388 PMCID: PMC6394991 DOI: 10.1371/journal.pone.0212970] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/12/2019] [Indexed: 11/19/2022] Open
Abstract
Human endogenous retroviruses are remnants of ancient germline infections that make up approximately 8% of the modern human genome. The HERV-K (HML-2) family is one of the most recent entrants into the human germline, these viruses appear to be transcriptionally active, and HERV-K viral like particles (VLPs) are found in cell lines from a number of human malignancies. HERV-K VLPs were first found to be produced in teratocarcinoma cell lines, and since then teratocarcinoma has been thought of as the classical model for HERV-Ks, with the NCCIT teratocarcinoma cell line particularly known to produce VLPs. Treatment for teratocarcinoma has progressed since its discovery, with improved prognosis for patients. Since the introduction of platinum based therapy, first year survival has greatly improved even with disseminated disease; however, it is estimated that 20% to 30% of patients present with metastatic germ cell tumor relapse following initial treatments. Also, the toxicity associated with the use of chemotherapeutic agents used to treat germ cell tumors is still a major concern. In this study, we show that the depletion of the HERV-K accessory protein Np9 increases the sensitivity of NCCIT teratocarcinoma cells to bleomycin and cisplatin. While decreasing the expression of Np9 had only a modest effect on the baseline viability of the cells, the reduced expression of Np9 increased the sensitivity of the teratocarcinoma cells to environmental (serum starvation) and chemical (chemotherapeutic) stresses. Np9 is also essential to the migration of NCCIT teratocarcinoma cells: in a wound closure assay, reduced expression of Np9 resulted in cells migrating into the wound at a slower rate, whereas reintroduction of Np9 resulted in NCCIT cells migrating back into the wound in a manner similar to the control. These findings support the implication that the HERV-K accessory protein Np9 has oncogenic potential.
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Affiliation(s)
- Susana M. Chan
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Tamar Sapir
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Sung-Soo Park
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jean-François Rual
- Department of Pathology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Rafael Contreras-Galindo
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Orly Reiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - David M. Markovitz
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
- Division of Infectious Diseases, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States of America
- Graduate Program in Immunology, University of Michigan, Ann Arbor, Michigan, United States of America
- Cancer Biology Program, University of Michigan, Ann Arbor, Michigan, United States of America
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9
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Trizzino M, Kapusta A, Brown CD. Transposable elements generate regulatory novelty in a tissue-specific fashion. BMC Genomics 2018; 19:468. [PMID: 29914366 PMCID: PMC6006921 DOI: 10.1186/s12864-018-4850-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 06/01/2018] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Transposable elements (TE) are an important source of evolutionary novelty in gene regulation. However, the mechanisms by which TEs contribute to gene expression are largely uncharacterized. RESULTS Here, we leverage Roadmap and GTEx data to investigate the association of TEs with active and repressed chromatin in 24 tissues. We find 112 human TE families enriched in active regions of the genome across tissues. Short Interspersed Nuclear Elements (SINEs) and DNA transposons are the most frequently enriched classes, while Long Terminal Repeat Retrotransposons (LTRs) are often enriched in a tissue-specific manner. We report across-tissue variability in TE enrichment in active regions. Genes with consistent expression across tissues are less likely to be associated with TE insertions. TE presence in repressed regions similarly follows tissue-specific patterns. Moreover, different TE classes correlate with different repressive marks: LTRs and Long Interspersed Nuclear Elements (LINEs) are overrepresented in regions marked by H3K9me3, while the other TEs are more likely to overlap regions with H3K27me3. Young TEs are typically enriched in repressed regions and depleted in active regions. We detect multiple instances of TEs that are enriched in tissue-specific active regulatory regions. Such TEs contain binding sites for transcription factors that are master regulators for the given tissue. These TEs are enriched in intronic enhancers, and their tissue-specific enrichment correlates with tissue-specific variations in the expression of the nearest genes. CONCLUSIONS We provide an integrated overview of the contribution of TEs to human gene regulation. Expanding previous analyses, we demonstrate that TEs can potentially contribute to the turnover of regulatory sequences in a tissue-specific fashion.
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Affiliation(s)
- Marco Trizzino
- Gene Expression and Regulation Program, The Wistar Institute, Philadelphia, PA, USA. .,Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA.
| | - Aurélie Kapusta
- Department of Human Genetics, University of Utah, Salt Lake City, UT, USA.,USTAR, Center for Genetic Discovery, Salt Lake City, UT, USA
| | - Christopher D Brown
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA. .,Institute for Biomedical Informatics, University of Pennsylvania, Philadelphia, PA, USA.
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10
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Ward MC, Zhao S, Luo K, Pavlovic BJ, Karimi MM, Stephens M, Gilad Y. Silencing of transposable elements may not be a major driver of regulatory evolution in primate iPSCs. eLife 2018; 7:33084. [PMID: 29648536 PMCID: PMC5943035 DOI: 10.7554/elife.33084] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Accepted: 04/11/2018] [Indexed: 12/16/2022] Open
Abstract
Transposable elements (TEs) comprise almost half of primate genomes and their aberrant regulation can result in deleterious effects. In pluripotent stem cells, rapidly evolving KRAB-ZNF genes target TEs for silencing by H3K9me3. To investigate the evolution of TE silencing, we performed H3K9me3 ChIP-seq experiments in induced pluripotent stem cells from 10 human and 7 chimpanzee individuals. We identified four million orthologous TEs and found the SVA and ERV families to be marked most frequently by H3K9me3. We found little evidence of inter-species differences in TE silencing, with as many as 82% of putatively silenced TEs marked at similar levels in humans and chimpanzees. TEs that are preferentially silenced in one species are a similar age to those silenced in both species and are not more likely to be associated with expression divergence of nearby orthologous genes. Our data suggest limited species-specificity of TE silencing across 6 million years of primate evolution.
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Affiliation(s)
- Michelle C Ward
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Medicine, University of Chicago, Chicago, United States
| | - Siming Zhao
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Kaixuan Luo
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Bryan J Pavlovic
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Mohammad M Karimi
- MRC London Institute of Medical Sciences, Imperial College, London, United Kingdom
| | - Matthew Stephens
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Statistics, University of Chicago, Chicago, United States
| | - Yoav Gilad
- Department of Human Genetics, University of Chicago, Chicago, United States.,Department of Medicine, University of Chicago, Chicago, United States
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11
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Susceptibility of Human Endogenous Retrovirus Type K to Reverse Transcriptase Inhibitors. J Virol 2017; 91:JVI.01309-17. [PMID: 28931682 DOI: 10.1128/jvi.01309-17] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/14/2017] [Indexed: 12/13/2022] Open
Abstract
Human endogenous retroviruses (HERVs) make up 8% of the human genome. The HERV type K (HERV-K) HML-2 (HK2) family contains proviruses that are the most recent entrants into the human germ line and are transcriptionally active. In HIV-1 infection and cancer, HK2 genes produce retroviral particles that appear to be infectious, yet the replication capacity of these viruses and potential pathogenicity has been difficult to ascertain. In this report, we screened the efficacy of commercially available reverse transcriptase inhibitors (RTIs) at inhibiting the enzymatic activity of HK2 RT and HK2 genomic replication. Interestingly, only one provirus, K103, was found to encode a functional RT among those examined. Several nucleoside analogue RTIs (NRTIs) blocked K103 RT activity and consistently inhibited the replication of HK2 genomes. The NRTIs zidovudine (AZT), stavudine (d4T), didanosine (ddI), and lamivudine (3TC), and the nucleotide RTI inhibitor tenofovir (TDF), show efficacy in blocking K103 RT. HIV-1-specific nonnucleoside RTIs (NNRTIs), protease inhibitors (PIs), and integrase inhibitors (IIs) did not affect HK2, except for the NNRTI etravirine (ETV). The inhibition of HK2 infectivity by NRTIs appears to take place at either the reverse transcription step of the viral genome prior to HK2 viral particle formation and/or in the infected cells. Inhibition of HK2 by these drugs will be useful in suppressing HK2 infectivity if these viruses prove to be pathogenic in cancer, neurological disorders, or other diseases associated with HK2. The present studies also elucidate a key aspect of the life cycle of HK2, specifically addressing how they do, and/or did, replicate.IMPORTANCE Endogenous retroviruses are relics of ancestral virus infections in the human genome. The most recent of these infections was caused by HK2. While HK2 often remains silent in the genome, this group of viruses is activated in HIV-1-infected and cancer cells. Recent evidence suggests that these viruses are infectious, and the potential exists for HK2 to contribute to disease. We show that HK2, and specifically the enzyme that mediates virus replication, can be inhibited by a panel of drugs that are commercially available. We show that several drugs block HK2 with different efficacies. The inhibition of HK2 replication by antiretroviral drugs appears to occur in the virus itself as well as after infection of cells. Therefore, these drugs might prove to be an effective treatment by suppressing HK2 infectivity in diseases where these viruses have been implicated, such as cancer and neurological syndromes.
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Blinov VM, Zverev VV, Krasnov GS, Filatov FP, Shargunov AV. Viral component of the human genome. Mol Biol 2017; 51:205-215. [PMID: 32214476 PMCID: PMC7089383 DOI: 10.1134/s0026893317020066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Revised: 04/27/2016] [Indexed: 12/17/2022]
Abstract
Relationships between viruses and their human host are traditionally described from the point of view taking into consideration hosts as victims of viral aggression, which results in infectious diseases. However, these relations are in fact two-sided and involve modifications of both the virus and host genomes. Mutations that accumulate in the populations of viruses and hosts may provide them advantages such as the ability to overcome defense barriers of host cells or to create more efficient barriers to deal with the attack of the viral agent. One of the most common ways of reinforcing anti-viral barriers is the horizontal transfer of viral genes into the host genome. Within the host genome, these genes may be modified and extensively expressed to compete with viral copies and inhibit the synthesis of their products or modulate their functions in other ways. This review summarizes the available data on the horizontal gene transfer between viral and human genomes and discusses related problems.
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Affiliation(s)
- V M Blinov
- 1Mechnikov Research Institute of Vaccines and Sera, Moscow, 105064 Russia
| | - V V Zverev
- 1Mechnikov Research Institute of Vaccines and Sera, Moscow, 105064 Russia
| | - G S Krasnov
- 1Mechnikov Research Institute of Vaccines and Sera, Moscow, 105064 Russia.,2Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 111911 Russia.,3Orekhovich Research Institute of Biomedical Chemistry, Moscow, 119121 Russia
| | - F P Filatov
- 1Mechnikov Research Institute of Vaccines and Sera, Moscow, 105064 Russia.,Gamaleya Research Center of Epidemiology and Microbiology, Moscow, 123098 Russia
| | - A V Shargunov
- 1Mechnikov Research Institute of Vaccines and Sera, Moscow, 105064 Russia
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Laska MJ, Troldborg A, Hauge EM, Bahrami S, Stengaard-Pedersen K. Human Endogenous Retroviral Genetic Element With Immunosuppressive Activity in Both Human Autoimmune Diseases and Experimental Arthritis. Arthritis Rheumatol 2017; 69:398-409. [DOI: 10.1002/art.39867] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 09/01/2016] [Indexed: 11/05/2022]
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Göke J, Ng HH. CTRL+INSERT: retrotransposons and their contribution to regulation and innovation of the transcriptome. EMBO Rep 2016; 17:1131-44. [PMID: 27402545 DOI: 10.15252/embr.201642743] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 06/20/2016] [Indexed: 12/25/2022] Open
Abstract
The human genome contains millions of fragments from retrotransposons-highly repetitive DNA sequences that were once able to "copy and paste" themselves to other regions in the genome. However, the majority of retrotransposons have lost this capacity through acquisition of mutations or through endogenous silencing mechanisms. Without this imminent threat of transposition, retrotransposons have the potential to act as a major source of genomic innovation. Indeed, large numbers of retrotransposons have been found to be active in specific contexts: as gene regulatory elements and promoters for protein-coding genes or long noncoding RNAs, among others. In this review, we summarise recent findings about retrotransposons, with implications in gene expression regulation, the expansion of gene isoform diversity and the generation of long noncoding RNAs. We highlight key examples that demonstrate their role in cellular identity and their versatility as markers of cell states, and we discuss how their dysregulation may contribute to the formation of and possibly therapeutic response in human cancers.
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Affiliation(s)
- Jonathan Göke
- Computational and Systems Biology, Genome Institute of Singapore, Singapore
| | - Huck Hui Ng
- Gene Regulation Laboratory, Genome Institute of Singapore, Singapore Department of Biochemistry, National University of Singapore, Singapore Department of Biological Sciences, National University of Singapore, Singapore School of Biological Sciences, Nanyang Technological University, Singapore
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15
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A survey of endogenous retrovirus (ERV) sequences in the vicinity of multiple sclerosis (MS)-associated single nucleotide polymorphisms (SNPs). Mol Biol Rep 2016; 43:827-36. [PMID: 27169423 DOI: 10.1007/s11033-016-4004-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 05/04/2016] [Indexed: 12/18/2022]
Abstract
Although multiple sclerosis (MS) is one of the most common central nervous system diseases in young adults, little is known about its etiology. Several human endogenous retroviruses (ERVs) are considered to play a role in MS. We are interested in which ERVs can be identified in the vicinity of MS associated genetic marker to find potential initiators of MS. We analysed the chromosomal regions surrounding 58 single nucleotide polymorphisms (SNPs) that are associated with MS identified in one of the last major genome wide association studies. We scanned these regions for putative endogenous retrovirus sequences with large open reading frames (ORFs). We observed that more retrovirus-related putative ORFs exist in the relatively close vicinity of SNP marker indices in multiple sclerosis compared to control SNPs. We found very high homologies to HERV-K, HCML-ARV, XMRV, Galidia ERV, HERV-H/env62 and XMRV-like mouse endogenous retrovirus mERV-XL. The associated genes (CYP27B1, CD6, CD58, MPV17L2, IL12RB1, CXCR5, PTGER4, TAGAP, TYK2, ICAM3, CD86, GALC, GPR65 as well as the HLA DRB1*1501) are mainly involved in the immune system, but also in vitamin D regulation. The most frequently detected ERV sequences are related to the multiple sclerosis-associated retrovirus, the human immunodeficiency virus 1, HERV-K, and the Simian foamy virus. Our data shows that there is a relation between MS associated SNPs and the number of retroviral elements compared to control. Our data identifies new ERV sequences that have not been associated with MS, so far.
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16
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Christensen T. Human endogenous retroviruses in neurologic disease. APMIS 2016; 124:116-26. [DOI: 10.1111/apm.12486] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 10/26/2015] [Indexed: 12/13/2022]
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Haase K, Mösch A, Frishman D. Differential expression analysis of human endogenous retroviruses based on ENCODE RNA-seq data. BMC Med Genomics 2015; 8:71. [PMID: 26530187 PMCID: PMC4632268 DOI: 10.1186/s12920-015-0146-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 10/28/2015] [Indexed: 11/24/2022] Open
Abstract
Background Human endogenous retroviruses (HERVs) are flanked by long terminal repeats (LTRs), which possess promoter activity and can therefore influence the expression of neighboring genes. HERV involvement in different types of cancer has already been thoroughly documented. However, so far there has been no systematic study of HERV expression patterns in a multitude of cell types in health and disease. In particular, the publication of the comprehensive ENCODE dataset has already facilitated many gene expression studies, but none so far focusing exclusively on HERVs. Results We present a comprehensive differential analysis of HERV expression based on ENCODE Tier 1 and Tier 2 RNA-seq data produced by Cold Spring Harbor Laboratories and the California Institute of Technology. This analysis was conducted for individual HERV loci and for entire HERV families in twelve different cell lines, of which six correspond to the normal condition and the other six represent cancer cell types. Although the principal component analysis revealed that the two groups of cells show distinguishable expression patterns, we were not able to link these differences to one or multiple particular HERV families. Two samples exhibit expression patterns, which are not similar to the corresponding cell lines of the other producing lab. Instead they show signs of cancer formation and expression of the pluripotency marker HERVH, despite being classified as a normal cell line and a differentiated cell, respectively. Conclusions Our study demonstrates that ENCODE data are generally comparable between the different contributing labs and that the analysis of HERV elements can provide novel insights into differentiation and disease state of a cell that are easily overlooked when focusing on protein-coding genes. Our findings hint at a change in HERV expression during cancerogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12920-015-0146-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kerstin Haase
- Department of Genome Oriented Bioinformatics, Wissenschaftszentrum Weihenstephan, TU München, Maximus-von-Imhof-Forum 3, Freising, 85354, Germany.
| | - Anja Mösch
- Department of Genome Oriented Bioinformatics, Wissenschaftszentrum Weihenstephan, TU München, Maximus-von-Imhof-Forum 3, Freising, 85354, Germany.
| | - Dmitrij Frishman
- Department of Genome Oriented Bioinformatics, Wissenschaftszentrum Weihenstephan, TU München, Maximus-von-Imhof-Forum 3, Freising, 85354, Germany. .,Helmholtz Center Munich - German Research Center for Environmental Health (GmbH), Institute of Bioinformatics and Systems Biology, Ingolstädter Landstraße 1, Neuherberg, 85764, Germany. .,St Petersburg State Polytechnical University, St. Petersburg, 195251, Russia.
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Contreras-Galindo R, Kaplan MH, Dube D, Gonzalez-Hernandez MJ, Chan S, Meng F, Dai M, Omenn GS, Gitlin SD, Markovitz DM. Human Endogenous Retrovirus Type K (HERV-K) Particles Package and Transmit HERV-K-Related Sequences. J Virol 2015; 89:7187-201. [PMID: 25926654 PMCID: PMC4473553 DOI: 10.1128/jvi.00544-15] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/25/2015] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Human endogenous retroviruses (HERV) make up 8% of the human genome. While the youngest of these retroviruses, HERV-K(HML-2), termed HK2, is able to code for all viral proteins and produce virus-like particles, it is not known if these virus particles package and transmit HK2-related sequences. Here, we analyzed the capacity of HK2 for packaging and transmitting HK2 sequences. We created an HK2 probe, termed Bogota, which can be packaged into HK2 viruses, and transfected it into cells that make HK2 particles. Supernatants of the transfected cells, which contained HK2 viral particles, then were added to target cells, and the transmissibility of the HK2 Bogota reporter was tracked by G418 resistance. Our studies revealed that contemporary HK2 virions produced by some teratocarcinoma and breast cancer cell lines, as well as by peripheral blood lymphocytes from lymphoma patients, can package HK2 Bogota probes, and these viruses transmitted these probes to other cells. After transmission, HK2 Bogota transcripts undergo reverse transcription, a step impaired by antiretroviral agents or by introduction of mutations into the probe sequences required for reverse transcription. HK2 viruses were more efficiently transmitted in the presence of HK2 Rec or HIV-1 Tat and Vif. Transmitted Bogota probes formed episomes but did not integrate into the cellular genome. Resistance to integration might explain the relatively low number of HK2 insertions that were acquired during the last 25 million years of evolution. Whether transient transmission of modern HK2 sequences, which encode two putative oncoproteins, can lead to disease remains to be studied. IMPORTANCE Retroviruses invaded the genome of human ancestors over the course of millions of years, yet these viruses generally have been inactivated during evolution, with only remnants of these infectious sequences remaining in the human genome. One of these viruses, termed HK2, still is capable of producing virus particles, although these particles have been regarded as being noninfectious. Using a genetic probe derived from HK2, we have discovered that HK2 viruses produced in modern humans can package HK2 sequences and transmit them to various other cells. Furthermore, the genetic sequences packaged in HK2 undergo reverse transcription. The transmitted probe circularized in the cell and failed to integrate into the cellular genome. These findings suggest that modern HK2 viruses can package viral RNA and transmit it to other cells. Contrary to previous views, we provide evidence of an extracellular viral phase of modern HK2 viruses. We have no evidence of sustained, spreading infection.
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Affiliation(s)
| | - Mark H Kaplan
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Derek Dube
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Marta J Gonzalez-Hernandez
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Programs in Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - Susana Chan
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Fan Meng
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Manhong Dai
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Gilbert S Omenn
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Scott D Gitlin
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Comprehensive Cancer Center, University of Michigan, Ann Arbor, Michigan, USA Veteran Affairs Health System, Ann Arbor, Michigan, USA
| | - David M Markovitz
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Programs in Immunology, University of Michigan, Ann Arbor, Michigan, USA Programs in Cancer Biology, University of Michigan, Ann Arbor, Michigan, USA Programs in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan, USA
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19
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Zahn J, Kaplan MH, Fischer S, Dai M, Meng F, Saha AK, Cervantes P, Chan SM, Dube D, Omenn GS, Markovitz DM, Contreras-Galindo R. Expansion of a novel endogenous retrovirus throughout the pericentromeres of modern humans. Genome Biol 2015; 16:74. [PMID: 25886262 PMCID: PMC4425911 DOI: 10.1186/s13059-015-0641-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 03/23/2015] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Approximately 8% of the human genome consists of sequences of retroviral origin, a result of ancestral infections of the germ line over millions of years of evolution. The most recent of these infections is attributed to members of the human endogenous retrovirus type-K (HERV-K) (HML-2) family. We recently reported that a previously undetected, large group of HERV-K (HML-2) proviruses, which are descendants of the ancestral K111 infection, are spread throughout human centromeres. RESULTS Studying the genomes of certain cell lines and the DNA of healthy individuals that seemingly lack K111, we discover new HERV-K (HML-2) members hidden in pericentromeres of several human chromosomes. All are related through a common ancestor, termed K222, which is a virus that infected the germ line approximately 25 million years ago. K222 exists as a single copy in the genomes of baboons and high order primates, but not New World monkeys, suggesting that progenitor K222 infected the primate germ line after the split between New and Old World monkeys. K222 exists in modern humans at multiple loci spread across the pericentromeres of nine chromosomes, indicating it was amplified during the evolution of modern humans. CONCLUSIONS Copying of K222 may have occurred through recombination of the pericentromeres of different chromosomes during human evolution. Evidence of recombination between K111 and K222 suggests that these retroviral sequences have been templates for frequent cross-over events during the process of centromere recombination in humans.
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Affiliation(s)
- Joseph Zahn
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Mark H Kaplan
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Sabrina Fischer
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Manhong Dai
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Fan Meng
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, 48109, USA.
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Anjan Kumar Saha
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Patrick Cervantes
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Susana M Chan
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Derek Dube
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Gilbert S Omenn
- Departments of Computational Medicine and Bioinformatics, Internal Medicine, and Human Genetics, and School of Public Health, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - David M Markovitz
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, MI, 48109-5640, USA.
| | - Rafael Contreras-Galindo
- Department of Internal Medicine, Division of Infectious Diseases and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Department of Internal Medicine, Division of Infectious Diseases, University of Michigan, Ann Arbor, MI, 48109-5640, USA.
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Diminished humoral responses against and reduced gene expression levels of human endogenous retrovirus-K (HERV-K) in psoriasis. J Transl Med 2014; 12:256. [PMID: 25224121 PMCID: PMC4174287 DOI: 10.1186/s12967-014-0256-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 09/05/2014] [Indexed: 11/15/2022] Open
Abstract
Background Psoriasis is a multifactorial, chronic disease of skin affecting 2-3% of the world’s population. Genetic studies of psoriasis have identified a number of susceptibility genes that are involved in anti-viral immunity. Furthermore, physiological studies have also found an increase in anti-viral proteins in psoriatic skin. These findings suggest the presence of an anti-viral state in psoriatic skin. However, the triggers for this anti-viral cascade and its consequences for host immunity are not known. Endogenous retroviruses have previously been described in many autoimmune diseases including psoriasis. Methods In the present study we examined the humoral immune response against human endogenous retrovirus-K (HERV-K) proteins and the cutaneous expression levels of multiple HERV-K genes in psoriasis patients and healthy controls. Results In psoriatic sera we observed a significant decrease in IgM response against three HERV-K proteins: Env surface unit (SU), Env transmembrane protein (TM), and Gag capsid (CA) in comparison to sera obtained from blood bank healthy controls. A decrease in IgG response was also observed against CA. Furthermore, using quantitative RT-PCR we observed a decrease in the expression of HERV-K Env, Gag, Pol and Rec as well as ERV-9 genes in lesional psoriatic skin as compared to healthy skin. Conclusions Together, our results suggest that the pro-inflammatory, anti-viral state in psoriasis is associated with diminished expression of HERV-K gene transcripts and a concomitant decrease in humoral responses to HERV-K. Our results indicate that a simple model where continuous, minimally changing HERV-K expression serves as an antigenic trigger in psoriasis might not be correct and further studies are needed to decipher the possible relationship between psoriasis and HERVs. Electronic supplementary material The online version of this article (doi:10.1186/s12967-014-0256-4) contains supplementary material, which is available to authorized users.
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21
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Gonzalez-Hernandez MJ, Cavalcoli JD, Sartor MA, Contreras-Galindo R, Meng F, Dai M, Dube D, Saha AK, Gitlin SD, Omenn GS, Kaplan MH, Markovitz DM. Regulation of the human endogenous retrovirus K (HML-2) transcriptome by the HIV-1 Tat protein. J Virol 2014; 88:8924-35. [PMID: 24872592 PMCID: PMC4136263 DOI: 10.1128/jvi.00556-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 05/22/2014] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Approximately 8% of the human genome is made up of endogenous retroviral sequences. As the HIV-1 Tat protein activates the overall expression of the human endogenous retrovirus type K (HERV-K) (HML-2), we used next-generation sequencing to determine which of the 91 currently annotated HERV-K (HML-2) proviruses are regulated by Tat. Transcriptome sequencing of total RNA isolated from Tat- and vehicle-treated peripheral blood lymphocytes from a healthy donor showed that Tat significantly activates expression of 26 unique HERV-K (HML-2) proviruses, silences 12, and does not significantly alter the expression of the remaining proviruses. Quantitative reverse transcription-PCR validation of the sequencing data was performed on Tat-treated PBLs of seven donors using provirus-specific primers and corroborated the results with a substantial degree of quantitative similarity. IMPORTANCE The expression of HERV-K (HML-2) is tightly regulated but becomes markedly increased following infection with HIV-1, in part due to the HIV-1 Tat protein. The findings reported here demonstrate the complexity of the genome-wide regulation of HERV-K (HML-2) expression by Tat. This work also demonstrates that although HERV-K (HML-2) proviruses in the human genome are highly similar in terms of DNA sequence, modulation of the expression of specific proviruses in a given biological situation can be ascertained using next-generation sequencing and bioinformatics analysis.
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Affiliation(s)
- Marta J Gonzalez-Hernandez
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Program in Immunology, University of Michigan, Ann Arbor, Michigan, USA
| | - James D Cavalcoli
- Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA
| | - Maureen A Sartor
- Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA Department of Biostatistics, University of Michigan, Ann Arbor, Michigan, USA School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Fan Meng
- Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Manhong Dai
- Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan, USA
| | - Derek Dube
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Anjan K Saha
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Scott D Gitlin
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Department of Veterans Affairs, University of Michigan, Ann Arbor, Michigan, USA
| | - Gilbert S Omenn
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Michigan, USA School of Public Health, University of Michigan, Ann Arbor, Michigan, USA National Center for Integrative Biomedical Informatics, University of Michigan, Ann Arbor, Michigan, USA Department of Human Genetics, University of Michigan, Ann Arbor, Michigan, USA
| | - Mark H Kaplan
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - David M Markovitz
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, USA Program in Immunology, University of Michigan, Ann Arbor, Michigan, USA Program in Cancer Biology, University of Michigan, Ann Arbor, Michigan, USA Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan, USA
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Reis BS, Jungbluth AA, Frosina D, Holz M, Ritter E, Nakayama E, Ishida T, Obata Y, Carver B, Scher H, Scardino PT, Slovin S, Subudhi SK, Reuter VE, Savage C, Allison JP, Melamed J, Jäger E, Ritter G, Old LJ, Gnjatic S. Prostate cancer progression correlates with increased humoral immune response to a human endogenous retrovirus GAG protein. Clin Cancer Res 2013; 19:6112-25. [PMID: 24081977 DOI: 10.1158/1078-0432.ccr-12-3580] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Human endogenous retroviruses (HERV) encode 8% of the human genome. While HERVs may play a role in autoimmune and neoplastic disease, no mechanistic association has yet been established. We studied the expression and immunogenicity of a HERV-K GAG protein encoded on chromosome 22q11.23 in relation to the clinical course of prostate cancer. EXPERIMENTAL DESIGN In vitro expression of GAG-HERV-K was analyzed in panels of normal and malignant tissues, microarrays, and cell lines, and effects of demethylation and androgen stimulation were evaluated. Patient sera were analyzed for seroreactivity to GAG-HERV-K and other self-antigens by ELISA and seromics (protein array profiling). RESULTS GAG-HERV-K expression was most frequent in prostate tissues and regulated both by demethylation of the promoter region and by androgen stimulation. Serum screening revealed that antibodies to GAG-HERV-K are found in a subset of patients with prostate cancer (33 of 483, 6.8%) but rarely in male healthy donors (1 of 55, 1.8%). Autoantibodies to GAG-HERV-K occurred more frequently in patients with advanced prostate cancer (29 of 191 in stage III-IV, 21.0%) than in early prostate cancer (4 of 292 in stages I-II, 1.4%). Presence of GAG-HERV-K serum antibody was correlated with worse survival of patients with prostate cancer, with a trend for faster biochemical recurrence in patients with antibodies to GAG-HERV-K. CONCLUSIONS Preferential expression of GAG-HERV-K ch22q11.23 in prostate cancer tissue and increased frequency of autoantibodies observed in patients with advanced prostate cancer make this protein one of the first bona fide retroviral cancer antigens in humans, with potential as a biomarker for progression and biochemical recurrence rate of prostate cancer. Clin Cancer Res; 19(22); 6112-25. ©2013 AACR.
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Affiliation(s)
- Bernardo Sgarbi Reis
- Authors' Affiliations: Ludwig Institute for Cancer Research, New York Branch at Memorial Sloan-Kettering Cancer Center; Departments of Surgery, Medicine, Pathology, Biostatistics, and Immunology, Memorial Sloan-Kettering Cancer Center; NYU Langone Medical Center, New York; Department of Immunology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama; RIKEN Bioresource Center, Tsukuba, Ibaraki, Japan; and Klinik für Onkologie und Hämatologie, Krankenhaus Nordwest, Frankfurt, Germany
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Contreras-Galindo R, Kaplan MH, He S, Contreras-Galindo AC, Gonzalez-Hernandez MJ, Kappes F, Dube D, Chan SM, Robinson D, Meng F, Dai M, Gitlin SD, Chinnaiyan AM, Omenn GS, Markovitz DM. HIV infection reveals widespread expansion of novel centromeric human endogenous retroviruses. Genome Res 2013; 23:1505-13. [PMID: 23657884 PMCID: PMC3759726 DOI: 10.1101/gr.144303.112] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 04/30/2013] [Indexed: 12/17/2022]
Abstract
Human endogenous retroviruses (HERVs) make up 8% of the human genome. The HERV-K (HML-2) family is the most recent group of these viruses to have inserted into the genome, and we have detected the activation of HERV-K (HML-2) proviruses in the blood of patients with HIV-1 infection. We report that HIV-1 infection activates expression of a novel HERV-K (HML-2) provirus, termed K111, present in multiple copies in the centromeres of chromosomes throughout the human genome yet not annotated in the most recent human genome assembly. Infection with HIV-1 or stimulation with the HIV-1 Tat protein leads to the activation of K111 proviruses. K111 is present as a single copy in the genome of the chimpanzee, yet K111 is not found in the genomes of other primates. Remarkably, K111 proviruses appear in the genomes of the extinct Neanderthal and Denisovan, while modern humans have at least 100 K111 proviruses spread across the centromeres of 15 chromosomes. Our studies suggest that the progenitor K111 integrated before the Homo-Pan divergence and expanded in copy number during the evolution of hominins, perhaps by recombination. The expansion of K111 provides sequence evidence suggesting that recombination between the centromeres of various chromosomes took place during the evolution of humans. K111 proviruses show significant sequence variations in each individual centromere, which may serve as markers in future efforts to annotate human centromere sequences. Further, this work is an example of the potential to discover previously unknown genomic sequences through the analysis of nucleic acids found in the blood of patients.
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Affiliation(s)
- Rafael Contreras-Galindo
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Mark H. Kaplan
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Shirley He
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Angie C. Contreras-Galindo
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Marta J. Gonzalez-Hernandez
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Ferdinand Kappes
- Institute of Biochemistry and Molecular Biology, Medical School, RWTH Aachen University, 52074 Aachen, Germany
| | - Derek Dube
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Susana M. Chan
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Dan Robinson
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
- Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
| | - Fan Meng
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Psychiatry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Manhong Dai
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Scott D. Gitlin
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
- Veteran Affairs Health System, Ann Arbor, Michigan 48105, USA
| | - Arul M. Chinnaiyan
- Michigan Center for Translational Pathology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
- Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
- Howard Hughes Medical Institute
| | - Gilbert S. Omenn
- Departments of Computational Medicine and Bioinformatics, Internal Medicine, and Human Genetics, and School of Public Health, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - David M. Markovitz
- Department of Internal Medicine, and Programs in Immunology, Cancer Biology, and Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Comprehensive Cancer Center, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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24
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Yu HL, Zhao ZK, Zhu F. The role of human endogenous retroviral long terminal repeat sequences in human cancer (Review). Int J Mol Med 2013; 32:755-62. [PMID: 23900638 DOI: 10.3892/ijmm.2013.1460] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2013] [Accepted: 05/30/2013] [Indexed: 11/06/2022] Open
Abstract
Human endogenous retrovirus (HERV) and solitary long terminal repeats (LTRs) constitute 8% of the human genome. Although most HERV genes are partially deleted and not intact, HERV LTRs comprise features including promoters, enhancers, selective splicer sites and polyadenylation sites in order to regulate the expression of neighboring genes. Owing to the genetic instability of LTRs, their wide distributions along human chromosomes are not only non-random, but are also correlated with gene density. Considerable evidence indicates that HERV LTRs regulate the expression of their adjacent viral and cellular genes in placental development and tumorigenesis. However, the regulatory mechanism of HERV LTRs on the expression of its neighboring cancer-associated genes in human cancers remains to be elucidated. Insertional mutagenesis, recombination and polymorphism are three principal factors of LTR that contribute to its genetic instability. Moreover, genetic instability, hypomethylation, transactivation and the antisense transcript of LTRs enhance the activity of LTRs and regulate the expression of their adjacent genes in human cancers. Therefore, in the present review, we examined the mechanism of HERV LTRs in tumorigenesis in combination with the structure and function of LTRs.
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Affiliation(s)
- Hong-Lian Yu
- Department of Medical Microbiology, School of Medicine, Wuhan University, Wuhan, Hubei 430071, PR China
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25
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Wilming LG, Hart EA, Coggill PC, Horton R, Gilbert JGR, Clee C, Jones M, Lloyd C, Palmer S, Sims S, Whitehead S, Wiley D, Beck S, Harrow JL. Sequencing and comparative analysis of the gorilla MHC genomic sequence. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2013; 2013:bat011. [PMID: 23589541 PMCID: PMC3626023 DOI: 10.1093/database/bat011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Major histocompatibility complex (MHC) genes play a critical role in vertebrate immune response and because the MHC is linked to a significant number of auto-immune and other diseases it is of great medical interest. Here we describe the clone-based sequencing and subsequent annotation of the MHC region of the gorilla genome. Because the MHC is subject to extensive variation, both structural and sequence-wise, it is not readily amenable to study in whole genome shotgun sequence such as the recently published gorilla genome. The variation of the MHC also makes it of evolutionary interest and therefore we analyse the sequence in the context of human and chimpanzee. In our comparisons with human and re-annotated chimpanzee MHC sequence we find that gorilla has a trimodular RCCX cluster, versus the reference human bimodular cluster, and additional copies of Class I (pseudo)genes between Gogo-K and Gogo-A (the orthologues of HLA-K and -A). We also find that Gogo-H (and Patr-H) is coding versus the HLA-H pseudogene and, conversely, there is a Gogo-DQB2 pseudogene versus the HLA-DQB2 coding gene. Our analysis, which is freely available through the VEGA genome browser, provides the research community with a comprehensive dataset for comparative and evolutionary research of the MHC.
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Affiliation(s)
- Laurens G Wilming
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire CB10 1HH, UK
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26
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The viral oncogene Np9 acts as a critical molecular switch for co-activating β-catenin, ERK, Akt and Notch1 and promoting the growth of human leukemia stem/progenitor cells. Leukemia 2013; 27:1469-78. [PMID: 23307033 DOI: 10.1038/leu.2013.8] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 12/22/2012] [Accepted: 01/03/2013] [Indexed: 12/22/2022]
Abstract
HERV-K (human endogenous retrovirus type K) type 1-encoded Np9 is a tumor-specific biomarker, but its oncogenic role and targets in human leukemia remain elusive. We first identified Np9 as a potent viral oncogene in human leukemia. Silencing of Np9 inhibited the growth of myeloid and lymphoblastic leukemic cells, whereas expression of Np9 significantly promoted the growth of leukemia cells in vitro and in vivo. Np9 not only activated ERK, AKT and Notch1 pathways but also upregulated β-catenin essential for survival of leukemia stem cells. In human leukemia, Np9 protein level in leukemia patients was substantially higher than that in normal donors (56% vs 4.5%). Moreover, Np9 protein level was correlated with the number of leukemia stem/progenitor cells but not detected in normal CD34(+) hematopoietic stem cells. In addition, Np9-positive samples highly expressed leukemia-specific pol-env polyprotein, env and transmembrane proteins as well as viral particles. Thus, the viral oncogene Np9 is a critical molecular switch of multiple signaling pathways regulating the growth of leukemia stem/progenitor cells. These findings open a new perspective to understand the etiology of human common leukemia and provide a novel target for treating leukemia.
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27
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Betaretroviral envelope subunits are noncovalently associated and restricted to the mammalian class. J Virol 2012; 87:1937-46. [PMID: 23221553 DOI: 10.1128/jvi.01442-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The structure of the transmembrane subunit (TM) of the retroviral envelope glycoprotein (Env) is highly conserved among most retrovirus genera and includes a pair of cysteines that forms an intramolecular disulfide loop within the ectodomain. Alpha-, gamma-, and deltaretroviruses have a third cysteine, adjacent to the loop, which forms a disulfide bond between TM and the surface subunit (SU) of Env, while lentiviruses, which have noncovalently associated subunits, lack this third cysteine. The Betaretrovirus genus includes Jaagsiekte sheep retrovirus (JSRV) and mouse mammary tumor virus (MMTV), as well as many endogenous retroviruses. Envelope subunit association had not been characterized in the betaretroviruses, but lack of a third cysteine in the TM ectodomain suggested noncovalently associated subunits. We tested the Env proteins of JSRV and MMTV, as well as human endogenous retrovirus K (HERV-K)108--a betaretrovirus-like human endogenous retrovirus--for intersubunit bonding and found that, as in the lentiviruses, the Env subunits lack an intersubunit disulfide bond. Since these results suggest that the number of cysteines in the TM loop region readily distinguishes between covalent and noncovalent structure, we surveyed endogenous retroviral TM sequences in the genomes of vertebrates represented in public databases and found that (i) retroviruses with noncovalently associated subunits have been present during all of anthropoid evolution and (ii) the noncovalent env motif is limited to mammals, while the covalent type is found among five vertebrate classes. We discuss implications of these findings for retroviral evolution, cross-species transmissions, and recombination events involving the env gene.
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28
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Ormsby CE, Sengupta D, Tandon R, Deeks SG, Martin JN, Jones RB, Ostrowski MA, Garrison KE, Vázquez-Pérez JA, Reyes-Terán G, Nixon DF. Human endogenous retrovirus expression is inversely associated with chronic immune activation in HIV-1 infection. PLoS One 2012; 7:e41021. [PMID: 22879884 PMCID: PMC3413683 DOI: 10.1371/journal.pone.0041021] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 06/16/2012] [Indexed: 01/06/2023] Open
Abstract
Human endogenous retroviruses (HERV) are remnants of ancestral retroviral infections integrated into the germ line, and constitute approximately 8% of the genome. Several autoimmune disorders, malignancies, and infectious diseases such as HIV-1 are associated with higher HERV expression. The degree to which HERV expression in vivo results in persistent inflammation is not known. We studied the association of immune activation and HERV-K expression in 20 subjects with chronic, untreated progressive HIV-1 infection and 10 HIV-1 negative controls. The mean HERV-K gag and env RNA expression level in the HIV-1 infected cohort was higher than in the control group (p = 0.0003), and was negatively correlated with the frequency of activated CD38+HLA-DR+CD4+ T cells (Rho = -0.61; p = 0.01) and activated CD38+HLA-DR+CD8+ T cells (Rho = -0.51; p = 0.03). Although HIV-infected persons had higher levels of HERV-K RNA expression (as expected), the level of RNA expression was negatively associated with level of T cell activation. The mechanism for this unexpected association remains to be defined.
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Affiliation(s)
- Christopher E Ormsby
- Center for Research in Infectious Diseases, National Institute of Respiratory Diseases, Mexico City, Federal District, Mexico.
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29
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Biochemical analysis of the complex between the tetrameric export adapter protein Rec of HERV-K/HML-2 and the responsive RNA element RcRE pck30. J Virol 2012; 86:9079-87. [PMID: 22696641 DOI: 10.1128/jvi.00121-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The RNA export adaptor protein Rec, encoded for by the human endogenous retrovirus HERV-K/HML-2 elements, binds to the Rec responsive element (RcRE) located in the 3' untranslated region of HERV-K/HML-2 transcripts. Binding allows the nucleocytoplasmic export of unspliced viral RNA, thereby overcoming host restriction. Chemical probing of the secondary structure of the RcRE corroborated the theory that the RcRE forms a complex folded structure with seven stem-loop regions. Laser-induced liquid beam ion desorption mass spectrometry revealed that Rec forms stable tetramers, which are further stabilized upon RNA binding. The RNA protein complex consists of three Rec tetramers, which bind to multiple sites on the RcRE-preferentially to purine-rich motifs-which represent several low-affinity binding sites. Mutated RcREs, with one to three purine-rich motifs deleted, were still bound and exported by Rec, indicating that the complex folded structure of the RcRE is important for Rec binding. This suggests a binding model where up to three Rec tetramers bind to the complex folded structure of the RcRE and the binding seems to be tightened by recognition of the purine-rich motifs.
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30
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Denner J, Tönjes RR. Infection barriers to successful xenotransplantation focusing on porcine endogenous retroviruses. Clin Microbiol Rev 2012; 25:318-43. [PMID: 22491774 PMCID: PMC3346299 DOI: 10.1128/cmr.05011-11] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Xenotransplantation may be a solution to overcome the shortage of organs for the treatment of patients with organ failure, but it may be associated with the transmission of porcine microorganisms and the development of xenozoonoses. Whereas most microorganisms may be eliminated by pathogen-free breeding of the donor animals, porcine endogenous retroviruses (PERVs) cannot be eliminated, since these are integrated into the genomes of all pigs. Human-tropic PERV-A and -B are present in all pigs and are able to infect human cells. Infection of ecotropic PERV-C is limited to pig cells. PERVs may adapt to host cells by varying the number of LTR-binding transcription factor binding sites. Like all retroviruses, they may induce tumors and/or immunodeficiencies. To date, all experimental, preclinical, and clinical xenotransplantations using pig cells, tissues, and organs have not shown transmission of PERV. Highly sensitive and specific methods have been developed to analyze the PERV status of donor pigs and to monitor recipients for PERV infection. Strategies have been developed to prevent PERV transmission, including selection of PERV-C-negative, low-producer pigs, generation of an effective vaccine, selection of effective antiretrovirals, and generation of animals transgenic for a PERV-specific short hairpin RNA inhibiting PERV expression by RNA interference.
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31
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Villarreal LP. The source of self: genetic parasites and the origin of adaptive immunity. Ann N Y Acad Sci 2009; 1178:194-232. [PMID: 19845639 DOI: 10.1111/j.1749-6632.2009.05020.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Stable colonization of the host by viruses (genetic parasites) can alter the systems of host identity and provide immunity against related viruses. To attain the needed stability, some viruses of prokaryotes (P1 phage) use a strategy called an addiction module. The linked protective and destructive gene functions of an addiction module insures both virus persistence but will also destroy cells that interrupt this module and thereby prevent infection by competitors. Previously, I have generalized this concept to also include persistent and lytic states of virus infection, which can be considered as a virus addiction module. Such states often involve defective viruses. In this report, I examine the origin of the adaptive immune system from the perspective of a virus addiction module. The likely role of both endogenous and exogenous retroviruses, DNA viruses, and their defective elements is considered in the origin of all the basal components of adaptive immunity (T-cell receptor, RAG-mediated gene rearrangement, clonal lymphocyte proliferation, antigen surface presentation, apoptosis, and education of immune cells). It is concluded that colonization by viruses and their defectives provides a more coherent explanation for the origin of adaptive immunity.
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Affiliation(s)
- Luis P Villarreal
- Center for Virus Research, Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, USA.
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32
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Singh S, Kaye S, Gore ME, McClure MO, Bunker CB. The role of human endogenous retroviruses in melanoma. Br J Dermatol 2009; 161:1225-31. [PMID: 19785608 DOI: 10.1111/j.1365-2133.2009.09415.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sequencing of the human genome has established that our DNA harbours many endogenous retrovirus (ERV) sequences, remnants of ancestral exogenous retroviral infections fixed in the germline DNA. In recent years, human ERVs (HERVs) have been implicated in melanomagenesis. Retrovirus-like particles and the expression of HERV mRNA and proteins have been demonstrated in melanoma tissue. In addition, antibodies to HERV proteins have been observed in patients with melanoma. In vitro and mouse models have provided fascinating insights into the potential mechanisms of HERVs in melanomagenesis. This review considers the evidence associating HERVs with melanoma.
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Affiliation(s)
- S Singh
- Department of Dermatology, Chelsea and Westminster Hospital, Imperial College Faculty of Medicine, London, U.K.
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33
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Human endogenous retrovirus K (HML-2) elements in the plasma of people with lymphoma and breast cancer. J Virol 2008; 82:9329-36. [PMID: 18632860 DOI: 10.1128/jvi.00646-08] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Actively replicating endogenous retroviruses entered the human genome millions of years ago and became a stable part of the inherited genetic material. They subsequently acquired multiple mutations, leading to the assumption that these viruses no longer replicate. However, certain human tumor cell lines have been shown to release endogenous retroviral particles. Here we show that RNA from human endogenous retrovirus K (HERV-K) (HML-2), a relatively recent entrant into the human genome, can be found in very high titers in the plasma of patients with lymphomas and breast cancer as measured by either reverse transcriptase PCR or nucleic acid sequence-based amplification. Further, these titers drop dramatically with cancer treatment. We also demonstrate the presence of reverse transcriptase and viral RNA in plasma fractions that contain both immature and correctly processed HERV-K (HML-2) Gag and envelope proteins. Finally, using immunoelectron microscopy, we show the presence of HERV-K (HML-2) virus-like particles in the plasma of lymphoma patients. Taken together, these findings demonstrate that elements of the endogenous retrovirus HERV-K (HML-2) can be found in the blood of modern-day humans with certain cancers.
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34
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Voisset C, Weiss RA, Griffiths DJ. Human RNA "rumor" viruses: the search for novel human retroviruses in chronic disease. Microbiol Mol Biol Rev 2008; 72:157-96, table of contents. [PMID: 18322038 PMCID: PMC2268285 DOI: 10.1128/mmbr.00033-07] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Retroviruses are an important group of pathogens that cause a variety of diseases in humans and animals. Four human retroviruses are currently known, including human immunodeficiency virus type 1, which causes AIDS, and human T-lymphotropic virus type 1, which causes cancer and inflammatory disease. For many years, there have been sporadic reports of additional human retroviral infections, particularly in cancer and other chronic diseases. Unfortunately, many of these putative viruses remain unproven and controversial, and some retrovirologists have dismissed them as merely "human rumor viruses." Work in this field was last reviewed in depth in 1984, and since then, the molecular techniques available for identifying and characterizing retroviruses have improved enormously in sensitivity. The advent of PCR in particular has dramatically enhanced our ability to detect novel viral sequences in human tissues. However, DNA amplification techniques have also increased the potential for false-positive detection due to contamination. In addition, the presence of many families of human endogenous retroviruses (HERVs) within our DNA can obstruct attempts to identify and validate novel human retroviruses. Here, we aim to bring together the data on "novel" retroviral infections in humans by critically examining the evidence for those putative viruses that have been linked with disease and the likelihood that they represent genuine human infections. We provide a background to the field and a discussion of potential confounding factors along with some technical guidelines. In addition, some of the difficulties associated with obtaining formal proof of causation for common or ubiquitous agents such as HERVs are discussed.
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Affiliation(s)
- Cécile Voisset
- CNRS-UMR8161, Institut de Biologie de Lille et Institut Pasteur de Lille, Lille, France
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35
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Lee YN, Bieniasz PD. Reconstitution of an infectious human endogenous retrovirus. PLoS Pathog 2007; 3:e10. [PMID: 17257061 PMCID: PMC1781480 DOI: 10.1371/journal.ppat.0030010] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 12/13/2006] [Indexed: 12/29/2022] Open
Abstract
The human genome represents a fossil record of ancient retroviruses that once replicated in the ancestors of contemporary humans. Indeed, approximately 8% of human DNA is composed of sequences that are recognizably retroviral. Despite occasional reports associating human endogenous retrovirus (HERV) expression with human disease, almost all HERV genomes contain obviously inactivating mutations, and none are thought to be capable of replication. Nonetheless, one family of HERVs, namely HERV-K(HML-2), may have replicated in human ancestors less than 1 million years ago. By deriving a consensus sequence, we reconstructed a proviral clone (HERV-KCON) that likely resembles the progenitor of HERV-K(HML-2) variants that entered the human genome within the last few million years. We show that HERV-KCON Gag and protease proteins mediate efficient assembly and processing into retrovirus-like particles. Moreover, reporter genes inserted into the HERV-KCON genome and packaged into HERV-K particles are capable of infectious transfer and stable integration in a manner that requires reverse transcription. Additionally, we show that HERV-KCON Env is capable of pseudotyping HIV-1 particles and mediating entry into human and nonhuman cell lines. Furthermore, we show that HERV-KCON is resistant to inhibition by the human retrovirus restriction factors tripartite motif 5α and apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like (APOBEC) 3G but is inhibited by APOBEC 3F. Overall, the resurrection of this extinct infectious agent in a functional form from molecular fossils should enable studies of the molecular virology and pathogenic potential of this ancient human retrovirus. Retrovirus genomes integrate into the genomes of host cells. If the target cells of a particular retrovirus include germ-line cells, e.g., sperm or egg cells, then retroviral genomes can be inherited like cellular genes. So-called “endogenous” retroviruses have accumulated throughout evolution in the genomes of many organisms, including humans. While all known endogenous retroviruses of modern humans are unable to replicate as retroviruses, the human genome represents a fossil record of ancient retroviruses that once infected our ancestors. In this study, a collection of “dead” endogenous retroviral genomes in modern human DNA was used to deduce the approximate sequence of an ancestral retrovirus, human endogenous retrovirus (HERV)-K, that is now thought to be extinct. A pseudo-ancestral HERV-K DNA sequence was synthesized and used to produce viral proteins and RNA that could reconstitute the HERV-K replication cycle. Thus, the replication and biology of a once-extinct retrovirus can now be studied in the laboratory. Interestingly, reconstituted HERV-K replication experiments, and comparison of the reconstituted HERV-K DNA sequence with the dead HERV-Ks in modern human DNA, suggests that HERV-K may have been extinguished in humans in part by host defenses that induce mutation of retroviral DNA and that the reconstitution of the pseudo-ancestral HERV-K reversed these changes.
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Affiliation(s)
- Young Nam Lee
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York, United States of America
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, United States of America
| | - Paul D Bieniasz
- Aaron Diamond AIDS Research Center, The Rockefeller University, New York, New York, United States of America
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, United States of America
- * To whom correspondence should be addressed. E-mail:
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36
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Wang-Johanning F, Liu J, Rycaj K, Huang M, Tsai K, Rosen DG, Chen DT, Lu DW, Barnhart KF, Johanning GL. Expression of multiple human endogenous retrovirus surface envelope proteins in ovarian cancer. Int J Cancer 2007; 120:81-90. [PMID: 17013901 DOI: 10.1002/ijc.22256] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Individual classes of human endogenous retrovirus (HERV) genes and proteins are expressed in cancer, but expression of more than one type of HERV is rare. We report here the expression of multiple HERV genes and proteins in ovarian cell lines and tissues. Expression of HERV-K env mRNA was greater in ovarian epithelial tumors than in normal ovarian tissues (N = 254). The expression of this protein on the surface and in the cytoplasm of ovarian cancer cells was confirmed using anti-HERV-K specific antibody by flow cytometric analysis. The frequency of expression of HERV-K env protein in multitissue microarrays (N = 641) was determined by immunohistochemistry and a significant correlation with tumor histotype was found. A significantly increased expression of HERV-K was observed in tumors with low malignant potential and low grade, relative to expression in normal ovarian tissues. The increase in expression of HERV-K env protein took place in a stepwise fashion in serous papillary adenocarcinoma. Interestingly, we found that other classes of HERV env mRNAs, including ERV3 and HERV-E, are expressed in the same ovarian cancer tissues that expressed HERV-K. Furthermore, anti-HERV antibodies including anti-ERV3 (30%), anti-HERV-E (40%) and anti-HERV-K (55%) were detected in patients with ovarian cancer, but not in normal female controls. HERV env proteins are frequently transcribed and translated in ovarian epithelial tumors, and multiple HERV families are detectable in ovarian cancer. HERV env proteins, and especially those expressed on the cell surface, may serve as novel tumor targets for detection, diagnosis and immunotherapy of ovarian cancer.
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MESH Headings
- Adenocarcinoma, Clear Cell/metabolism
- Adenocarcinoma, Clear Cell/virology
- Adenocarcinoma, Mucinous/metabolism
- Adenocarcinoma, Mucinous/virology
- Adult
- Aged
- Aged, 80 and over
- Amino Acid Sequence
- Base Sequence
- Carcinoma, Endometrioid/metabolism
- Carcinoma, Endometrioid/virology
- Case-Control Studies
- Cystadenocarcinoma, Serous/metabolism
- Cystadenocarcinoma, Serous/virology
- Endogenous Retroviruses/genetics
- Endogenous Retroviruses/immunology
- Endogenous Retroviruses/metabolism
- Enzyme-Linked Immunosorbent Assay
- Female
- Flow Cytometry
- Fluorescent Antibody Technique
- Gene Products, env/genetics
- Gene Products, env/metabolism
- Gene Products, env/physiology
- Humans
- Immunoenzyme Techniques
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Middle Aged
- Molecular Sequence Data
- Ovarian Neoplasms/metabolism
- Ovarian Neoplasms/virology
- Ovary/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tissue Array Analysis
- Tumor Cells, Cultured
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Affiliation(s)
- Feng Wang-Johanning
- Department of Veterinary Sciences and Michale E. Keeling Center for Comparative Medicine and Research, University of Texas MD Anderson Cancer Center, Houston, TX 78602, USA.
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Mayer J, Stuhr T, Reus K, Maldener E, Kitova M, Asmus F, Meese E. Haplotype analysis of the human endogenous retrovirus locus HERV-K(HML-2.HOM) and its evolutionary implications. J Mol Evol 2005; 61:706-15. [PMID: 16211423 DOI: 10.1007/s00239-005-0066-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Accepted: 06/16/2005] [Indexed: 10/25/2022]
Abstract
We and others recently identified an almost-intact human endogenous retrovirus (HERV), termed HERV-K(HML-2.HOM), that is usually organized as a tandem provirus. Studies on HERV proviral loci commonly rely on the analysis of single alleles being taken as representative for a locus. We investigated the frequency of HERV-K(HML-2.HOM) single and tandem alleles in various human populations. Our analysis revealed that another HERV-K(HML-2) locus, the so-called HERV-K(II) provirus, is also present as a tandem provirus allele in the human population. Proviral tandem formations were identified in various nonhuman primate species. We furthermore examined single nucleotide polymorphisms (SNPs) within the HERV-K(HML-2.HOM) proviral gag, prt, and pol genes, which all result in nonsense mutations. We identified four proviral haplotypes displaying different combinations of gag, prt, and pol SNPs. Haplotypes harboring completely intact proviral genes were not found. For the left provirus of the tandem arrangement a haplotype displaying intact gag and prt genes and a mutated pol was found in about two-thirds of individuals from different ethnogeographic origins. The same haplotype was always found in the right provirus. The various haplotypes point toward multiple recombination events between HERV-K(HML-2.HOM) proviruses. Based on these findings we derive a model for the evolution of the proviral locus since germ line integration.
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Affiliation(s)
- Jens Mayer
- Department of Human Genetics, Bulding 60, Medical Faculty, University of Saarland, 66421 Homburg, Germany.
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38
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Szabo S, Haislip AM, Garry RF. Of mice, cats, and men: Is human breast cancer a Zoonosis? Microsc Res Tech 2005; 68:197-208. [PMID: 16276516 DOI: 10.1002/jemt.20232] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mouse mammary tumor virus (MMTV), a member of the betaretroviridae, is the most common cause of breast cancer (BC) in mice. MMTV is transmitted in mice both in the germline as endogenous proviruses and exogenously as infectious virions. Here, we review a variety of evidence accumulated for six decades that has suggested that a human homologue of MMTV may exist. The findings include recent studies from several independent laboratories that have detected sequences very closely related to MMTV in DNA isolated from human BC tumors. Other laboratories, however, have failed to detect the MMTV-related sequences in human DNA samples, and conclusive evidence for a human mammary tumor virus has been elusive. We also reviewed additional studies, suggesting that betaretroviruses are present in a much wider range of species than previously known, including rodents, felines, and primates. The observation that a subset of cats may be infected with a close homologue of MMTV may be of epidemiological significance for human BC. Cats may become infected by MMTV from mice, and in turn may transmit the virus to humans, possibly after selection for variants with an expanded host range.
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Affiliation(s)
- Sara Szabo
- Department of Pathology, Children's Hospital, New Orleans, Louisiana 70118, USA.
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39
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Misseri Y, Cerutti M, Devauchelle G, Bucheton A, Terzian C. Analysis of the Drosophila gypsy endogenous retrovirus envelope glycoprotein. J Gen Virol 2004; 85:3325-3331. [PMID: 15483247 DOI: 10.1099/vir.0.79911-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
gypsy is the only endogenous retrovirus of Drosophila whose infectious properties have been reported. Previous studies have shown an unexpected relationship between the gene encoding the putative envelope glycoprotein (Env) of gypsy and genes encoding the fusion protein of several baculoviruses. The fact that fusion proteins mediate membrane fusion suggests that Env of insect retroviruses might also have fusogenic properties. The results reported here indicate that gypsy Env mediates cell-to-cell fusion. Cleavage of the Env precursor was also studied; it is shown that this polypeptide is cleaved at a furin-like cleavage site. This is the first report that the env-like gene of insect retroviruses encodes a fusion protein.
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Affiliation(s)
- Yolande Misseri
- Institut de Génétique Humaine CNRS, 141 rue de la cardonille, 34396 Montpellier cedex 5, France
| | - Martine Cerutti
- Laboratoire de Pathologie Comparée, 30380 Saint Christol les Ales, France
| | - Gérard Devauchelle
- Laboratoire de Pathologie Comparée, 30380 Saint Christol les Ales, France
| | - Alain Bucheton
- Institut de Génétique Humaine CNRS, 141 rue de la cardonille, 34396 Montpellier cedex 5, France
| | - Christophe Terzian
- Ecole Pratique des Hautes Etudes - UMR 7625, Université Paris 6, cc237, 7 quai Saint Bernard, 75252 Paris cedex 05, France
- Institut de Génétique Humaine CNRS, 141 rue de la cardonille, 34396 Montpellier cedex 5, France
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40
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Mayer J, Ehlhardt S, Seifert M, Sauter M, Müller-Lantzsch N, Mehraein Y, Zang KD, Meese E. Human endogenous retrovirus HERV-K(HML-2) proviruses with Rec protein coding capacity and transcriptional activity. Virology 2004; 322:190-8. [PMID: 15063128 DOI: 10.1016/j.virol.2004.01.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Revised: 01/09/2004] [Accepted: 01/26/2004] [Indexed: 11/17/2022]
Abstract
The human endogenous retrovirus family HERV-K(HML-2) encodes the so-called Rec protein that displays functional similarities to the HIV(REV) protein. The number of proviruses producing Rec protein was hitherto unknown. We therefore analyzed the human genome sequence data and determined seven HERV-K(HML-2) proviruses potentially capable of producing Rec both on the mRNA and the protein level. We analyzed Rec mRNA expression in the Tera-1 cell line and in synovial tissue, and in the expressed sequence tag (EST) database. Diagnostic nucleotides assigned transcriptionally active and Rec-encoding proviruses to human chromosomes 6, 7, 11, and 12. Differently spliced mRNAs were also identified. The various active proviruses encode almost identical Rec proteins. Our study contributes to the understanding of the biology of HERV-K(HML-2) Rec protein. Our study further demonstrates that minor sequence differences among proviruses allow assigning HERV transcripts to particular proviral loci. Extended studies will eventually yield a more complete image of HERV transcription, regulation, and biological significance in diverse human tissues.
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Affiliation(s)
- Jens Mayer
- Department of Human Genetics, Medical Faculty, University of Saarland, 66421 Homburg/Saar, Germany.
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Abstract
The plethora of genomic information gathered by the sequencing of the human and mouse genomes has paved the way for a new era of genetics. While in the past we focused mainly on the small percentage of DNA that codes for proteins, we can now concentrate on the remainder, i.e. the noncoding sequences that interrupt and separate genes. This portion of the genome is made up, in most part, of repetitive DNA sequences including DNA transposons, long terminal repeat (LTR) retrotransposons, LINEs (long interspersed nuclear elements) and SINEs (short interspersed nuclear elements). Some of these elements are transcriptionally active and can transpose or retrotranspose around the genome, resulting in insertional mutagenesis that can cause disease. In these cases, insertions have occurred in the coding sequence. However, recent evidence suggests that the main effect of these elements is their ability to influence transcription of neighbouring genes. The elements themselves contain promoters that can initiate transcription of flanking genomic DNA. Furthermore, they are susceptible to epigenetic silencing, which is often stochastic and incomplete, resulting in complex patterns of transcription. This review discusses some diseases in both human and mouse that are caused by these repetitive elements.
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Affiliation(s)
- R Druker
- School of Molecular and Microbial Biosciences, University of Sydney, New South Wales, Australia
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Niebert M, Tönjes RR. Molecular cloning and functional characterization of infectious PERV and development of diagnostic tests. Curr Top Microbiol Immunol 2003; 278:217-37. [PMID: 12934946 DOI: 10.1007/978-3-642-55541-1_8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Pigs are the donor animals of choice for xenotransplantation (XTx) and xenogeneic cell therapy measurements. Most known porcine pathogens can be controlled by conventional means like vaccination, medication or specific pathogen-free breeding conditions. As pigs have co-evolved very closely with humans for a few millennia it is not very likely that even asymptomatic pathogens have escaped attention. Porcine endogenous retroviruses (PERV) are different from conventional pathogens as they are chromosomally fixed in every cell of the animal, hence PERV cannot be easily controlled. While PERV show no phenotype in the porcine host, recent data demonstrate that some polytropic proviruses can be activated by external stimuli and that those can productively infect human cells in vitro. In evaluation of the retrovirological safety of XTx, we determined the number of replication-competent PERV to be limited and to exhibit a heterogeneous distribution, therefore suggesting that they could be removed by conventional breeding. The transcriptional regulation of some PERV due to repetitive elements in their long terminal repeats enables their adaptation to new host cells. The diagnostic tools available, based on immunological and polymerase chain reaction techniques, were shown to be sensitive in both the animal and in vitro, but must still show their potential in human XTx recipients, where they are confronted with very low antigen expression and the phenomenon of microchimerism.
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Affiliation(s)
- M Niebert
- Paul-Ehrlich-Institut, Paul-Ehrlich-Strasse 51-59, 63225 Langen, Germany
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Nelson PN, Carnegie PR, Martin J, Davari Ejtehadi H, Hooley P, Roden D, Rowland-Jones S, Warren P, Astley J, Murray PG. Demystified. Human endogenous retroviruses. Mol Pathol 2003; 56:11-8. [PMID: 12560456 PMCID: PMC1187282 DOI: 10.1136/mp.56.1.11] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2002] [Indexed: 12/11/2022]
Abstract
Human endogenous retroviruses (HERVs) are a family of viruses within our genome with similarities to present day exogenous retroviruses. HERVs have been inherited by successive generations and it is possible that some have conferred biological benefits. However, several HERVs have been implicated in certain cancers and autoimmune diseases. This article demystifies these retroviruses by providing an insight into HERVs, their means of classification, and a synopsis of HERVs implicated in cancer and autoimmunity. Furthermore, the biological roles of HERVs are explored.
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Affiliation(s)
- P N Nelson
- School of Applied Sciences, Division of Biomedical Science and Biosciences, University of Wolverhampton, Wolverhampton WV1 1SB, UK.
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Beyer TD, Kolowos W, Dumitriu IE, Voll RE, Heyder P, Gaipl US, Kalden JR, Herrmann M. Apoptosis of the teratocarcinoma cell line Tera-1 leads to the cleavage of HERV-K10gag proteins by caspases and/or granzyme B. Scand J Immunol 2002; 56:303-9. [PMID: 12193232 DOI: 10.1046/j.1365-3083.2002.01139.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Redistribution, post-translational modifications and coclustering with viral antigens contribute to the immunogenicity of apoptotic cell-derived autoantigens. Almost all known targets of the humoral autoimmune response in systemic lupus erythematosus (SLE) are cleaved by caspases or granzyme B during apoptosis. Antibodies against retroviral proteins can frequently be detected in the sera of SLE patients without overt retroviral infections. These antibodies may represent cross-reactive antibodies or may have been induced by proteins encoded by endogenous retroviral sequences. We used Tera-1 cells that abundantly express a group-specific antigen of human endogenous retroviruses, HERV-K10gag polyprotein, to investigate its processing during apoptosis. Tera-1 cells induced to undergo apoptosis showed an altered HERV-K10gag processing compared with viable cells. In addition, granzyme B was able to cleave HERV-K10gag isolated from viable Tera-1 cells. Similar to nuclear autoantigens, endogenous retroviral proteins are cleaved during the execution phase of apoptosis. These post-translational modifications may result in the generation of T-cell neoepitopes or a changed epitope hierarchy of retroviral proteins. Therefore, immunogenicity of retroviral antigens in SLE patients may result from a similar mechanism as described for nuclear autoantigens.
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Affiliation(s)
- T D Beyer
- Institute of Clinical Immunology and Rheumatology, Department of Internal Medicine III, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Germany
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Andersson AC, Venables PJW, Tönjes RR, Scherer J, Eriksson L, Larsson E. Developmental expression of HERV-R (ERV3) and HERV-K in human tissue. Virology 2002; 297:220-5. [PMID: 12083821 DOI: 10.1006/viro.2002.1428] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human endogenous retroviruses (HERVs), ERV3 (HERV-R) and HERV-K, are both known to be transcriptionally active in human placenta. In the case of ERV3 there is also indirect evidence for its participation in cellular differentiation. In this study we examined the expression of ERV3 (HERV-R) and HERV-K in human normal fetal tissues by in situ hybridization. The highest level of ERV3 env expression was detected in primitive adrenal cortex. Elevated levels of expression were also found in the following developing tissues: kidneys (tubules), tongue, heart, liver, and central nervous system. Tissue-specific expression was found for HERV-K rec (former cORF) but not for pol/int transcripts. The highest rec expression was found in placenta and levels slightly higher than sense control were found in the rest of the tissues examined. Pol/Int was not possible to quantitate. It appears that ERV3 is expressed in an organ-specific way during embryogenesis and might suggest a possible role in the development and differentiation of human tissues.
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Herve CA, Lugli EB, Brand A, Griffiths DJ, Venables PJW. Autoantibodies to human endogenous retrovirus-K are frequently detected in health and disease and react with multiple epitopes. Clin Exp Immunol 2002; 128:75-82. [PMID: 11982593 PMCID: PMC1906363 DOI: 10.1046/j.1365-2249.2002.01735.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A number of studies have found increased levels of antibodies to human endogenous retroviruses (HERVs) in autoimmune rheumatic diseases. It is not clear whether this immune response is driven by the HERV itself or by cross-reactions with an exogenous virus or an autoantigen. To address this question, we examined the antibody response to the Env protein of two closely related members of the HERV-K family, HERV-K10 and IDDMK1,222. By immunoblotting of recombinant proteins, antibodies were found in 32-47% of 84 sera from patients with autoimmune rheumatic disease, and 29% of 35 normal controls. Epitope mapping with overlapping 15mers identified multiple reactive peptides on both antigens, with one (GKTCPKEIPKGSKNT) containing immunodominant epitope(s). By ELISA, the median titre of antibody to this peptide was significantly increased in 39 patients with SLE compared to 39 healthy controls and 86 patients with other rheumatic diseases (P < 0.003). We have shown that there is a high frequency of IgG antibodies to HERV-K env sequences in human sera, both in health and autoimmune rheumatic disease, and that the response is to multiple epitopes. This supports the hypothesis that the autoimmune response to HERV-K is antigen-driven and may be an early stage in the chain of events that leads to tolerance breakdown to other autoantigens.
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Affiliation(s)
- C A Herve
- Kennedy Institute of Rheumatology, London, UK.
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Misra A, Chosdol K, Sarkar C, Mahapatra AK, Sinha S. Alteration of a sequence with homology to human endogenous retrovirus (HERV-K) in primary human glioma: implications for viral repeat mediated rearrangement. Mutat Res 2001; 484:53-9. [PMID: 11733071 DOI: 10.1016/s0027-5107(01)00240-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We had earlier demonstrated that a comparison of DNA fingerprinting profiles of tumor and corresponding normal DNA from the same patient by random amplified polymorphic DNA (RAPD) analysis can readily demonstrate alterations in tumor DNA [Gene 206 (1998) 45 and J. Neuro Oncol. 48 (2000) 1]. These alterations could be used to identify changes in tumor DNA where the prior identity of the locus was not known. In this study, we report the identification, cloning and characterization of a RAPD amplified fragment which was lost in a glioma, a grade IV glioblastoma multiforme (GBM). Comparison of the RAPD profile of tumor and corresponding leucocyte DNA revealed several differences between the two. These included a band of 443 bases, which was demonstrated in the normal, but not in tumor DNA. On sequencing, this band was found to be homologous with a group of SINE sequences, which are probably derived from the human endogenous retrovirus-K (HERV-K). Homology search also reveals that HERV-K-derived sequences are interspersed, amongst others, in the tumor suppressor gene BRCA2 and the DNA repair gene XRCC1. Of particular interest is the inverted repeat pattern of HERV-derived sequences in the genes. While not demonstrating a cause effect relationship, this highlights the possible role of such virus-derived sequences in gene inactivation by recombination during tumorigenesis.
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Affiliation(s)
- A Misra
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, 110029, New Delhi, India
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48
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Kuhelj R, Rizzo CJ, Chang CH, Jadhav PK, Towler EM, Korant BD. Inhibition of human endogenous retrovirus-K10 protease in cell-free and cell-based assays. J Biol Chem 2001; 276:16674-82. [PMID: 11278433 DOI: 10.1074/jbc.m008763200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A full-length and C-terminally truncated version of human endogenous retrovirus (HERV)-K10 protease were expressed in Escherichia coli and purified to homogeneity. Both versions of the protease efficiently processed HERV-K10 Gag polyprotein substrate. HERV-K10 Gag was also cleaved by human immunodeficiency virus, type 1 (HIV-1) protease, although at different sites. To identify compounds that could inhibit protein processing dependent on the HERV-K10 protease, a series of cyclic ureas that had previously been shown to inhibit HIV-1 protease was tested. Several symmetric bisamides acted as very potent inhibitors of both the truncated and full-length form of HERV-K10 protease, in subnanomolar or nanomolar range, respectively. One of the cyclic ureas, SD146, can inhibit the processing of in vitro translated HERV-K10 Gag polyprotein substrate by HERV-K10 protease. In addition, in virus-like particles isolated from the teratocarcinoma cell line NCCIT, there is significant accumulation of Gag and Gag-Pol precursors upon treatment with SD146, suggesting the compound efficiently blocks HERV-K Gag processing in cells. This is the first report of an inhibitor able to block cell-associated processing of Gag polypeptides of an endogenous retrovirus.
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Affiliation(s)
- R Kuhelj
- Department of Virology, Experimental Station, DuPont Pharmaceuticals, Wilmington, Delaware 19880, USA
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49
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Voisset C, Tönjes RR, Breyton P, Mandrand B, Paranhos-Baccalà G. Specific detection of RT activity in culture supernantants of retrovirus-producing cells, using synthetic DNA as competitor in polymerase enhanced reverse transcriptase assay. J Virol Methods 2001; 94:187-93. [PMID: 11337053 DOI: 10.1016/s0166-0934(01)00255-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The polymerase enhanced reverse transcriptase (PERT) assay is a highly sensitive assay for the detection of reverse transcriptase (RT) activity in culture supernatants of retrovirus-producing cells. However, some cellular DNA-dependent DNA polymerases exhibit RT-like activities in this assay. A synthetic DNA competitor which suppresses the RT-like activities of cellular DNA-dependent DNA polymerases was used in a modified PERT assay technique for specific detection of RT activity in culture supernatants of retrovirus-producing cells. We determined the optimum condition of the assay and evaluated its specificity. This improved PERT assay is easy to perform and is able to detect minute amounts of purified RT, as well as RT in crude cell lysates and concentrated culture supernatants.
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Affiliation(s)
- C Voisset
- Unité Mixte de Recherche 2142 CNRS-bioMérieux, Ecole Normale Supérieure de Lyon, 46, allée d'Italie, 69364 Cedex 07, Lyon, France
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50
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Bieda K, Hoffmann A, Boller K. Phenotypic heterogeneity of human endogenous retrovirus particles produced by teratocarcinoma cell lines. J Gen Virol 2001; 82:591-596. [PMID: 11172100 DOI: 10.1099/0022-1317-82-3-591] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human endogenous retrovirus (HERV) sequences represent about 0.5% of the human genome. The only HERV known to express virus particles is human teratocarcinoma-derived virus (HTDV), which is now termed HTDV/HERV-K. Between 25 and 50 different copies of HERV-K are present in the human genome, three of which contain full-length genes for viral structural proteins. To determine whether genes of different HERV-K proviruses can be expressed, the morphologies and protein expression patterns of HTDV/HERV-K produced by various human teratocarcinoma cell lines were compared. Three different types of retrovirus-like particles were observed, showing differences in the presence of viral surface proteins and the existence of free mature virions. These distinct morphological features between virion types were in accordance with the results of immunoblotting analyses that revealed differences in the cleavage of a viral Gag protein precursor and the presence of a putative Env protein. These data suggest that different HERV-K proviruses are transcribed in human teratocarcinoma cell lines.
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Affiliation(s)
- Katrin Bieda
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany1
| | - Andreas Hoffmann
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany1
| | - Klaus Boller
- Paul-Ehrlich-Institut, Paul-Ehrlich-Straße 51-59, D-63225 Langen, Germany1
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