101
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Blackadar CB. Historical review of the causes of cancer. World J Clin Oncol 2016; 7:54-86. [PMID: 26862491 PMCID: PMC4734938 DOI: 10.5306/wjco.v7.i1.54] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/31/2015] [Accepted: 11/24/2015] [Indexed: 02/06/2023] Open
Abstract
In the early 1900s, numerous seminal publications reported that high rates of cancer occurred in certain occupations. During this period, work with infectious agents produced only meager results which seemed irrelevant to humans. Then in the 1980s ground breaking evidence began to emerge that a variety of viruses also cause cancer in humans. There is now sufficient evidence of carcinogenicity in humans for human T-cell lymphotrophic virus, human immunodeficiency virus, hepatitis B virus, hepatitis C virus, human papillomavirus, Epstein-Barr virus, and human herpes virus 8 according to the International Agency for Research on Cancer (IARC). Many other causes of cancer have also been identified by the IARC, which include: Sunlight, tobacco, pharmaceuticals, hormones, alcohol, parasites, fungi, bacteria, salted fish, wood dust, and herbs. The World Cancer Research Fund and the American Institute for Cancer Research have determined additional causes of cancer, which include beta carotene, red meat, processed meats, low fibre diets, not breast feeding, obesity, increased adult height and sedentary lifestyles. In brief, a historical review of the discoveries of the causes of human cancer is presented with extended discussions of the difficulties encountered in identifying viral causes of cancer.
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102
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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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103
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Wu HL, Léon EJ, Wallace LT, Nimiyongskul FA, Buechler MB, Newman LP, Castrovinci PA, Paul Johnson R, Gifford RJ, Brad Jones R, Sacha JB. Identification and spontaneous immune targeting of an endogenous retrovirus K envelope protein in the Indian rhesus macaque model of human disease. Retrovirology 2016; 13:6. [PMID: 26767784 PMCID: PMC4714462 DOI: 10.1186/s12977-016-0238-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 01/05/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections that have invaded the germ line of both humans and non-human primates. Most ERVs are functionally crippled by deletions, mutations, and hypermethylation, leading to the view that they are inert genomic fossils. However, some ERVs can produce mRNA transcripts, functional viral proteins, and even non-infectious virus particles during certain developmental and pathological processes. While there have been reports of ERV-specific immunity associated with ERV activity in humans, adaptive immune responses to ERV-encoded gene products remain poorly defined and have not been investigated in the physiologically relevant non-human primate model of human disease. FINDINGS Here, we identified the rhesus macaque equivalent of the biologically active human ERV-K (HML-2), simian ERV-K (SERV-K1), which retains intact open reading frames for both Gag and Env on chromosome 12 in the macaque genome. From macaque cells we isolated a spliced mRNA product encoding SERV-K1 Env, which possesses all the structural features of a canonical, functional retroviral Envelope protein. Furthermore, we identified rare, but robust T cell responses as well as frequent antibody responses targeting SERV-K1 Env in rhesus macaques. CONCLUSIONS These data demonstrate that SERV-K1 retains biological activity sufficient to induce cellular and humoral immune responses in rhesus macaques. As ERV-K is the youngest and most active ERV family in the human genome, the identification and characterization of the simian orthologue in rhesus macaques provides a highly relevant animal model in which to study the role of ERV-K in developmental and disease states.
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Affiliation(s)
- Helen L Wu
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, USA.
| | - Enrique J Léon
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, USA. .,Oregon National Primate Research Center, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR, 97007, USA.
| | - Lyle T Wallace
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Francesca A Nimiyongskul
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Matthew B Buechler
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Laura P Newman
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - Philip A Castrovinci
- Department of Pathology and Laboratory Medicine, University of Wisconsin-Madison, Madison, WI, USA.
| | - R Paul Johnson
- Yerkes National Primate Research Center, Emory University, Atlanta, GA, USA.
| | - Robert J Gifford
- MRC-University of Glasgow Centre for Virus Research, Glasgow, UK.
| | - R Brad Jones
- Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington DC, USA.
| | - Jonah B Sacha
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, USA. .,Oregon National Primate Research Center, Oregon Health and Science University, 505 NW 185th Avenue, Beaverton, OR, 97007, USA.
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104
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Determination of Sequences Required for Human Endogenous Retrovirus K Transduction and Its Recognition by Foreign Retroviral Virions. J Virol 2015; 90:3243-6. [PMID: 26719267 DOI: 10.1128/jvi.02731-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 12/16/2015] [Indexed: 11/20/2022] Open
Abstract
Sequences necessary for transduction of human endogenous retrovirus (HERV)-Kcon, a consensus of the HERV-K(HML-2) family, were analyzed and found to reside in the leader/gag region. They act in an orientation-dependent way and consist of at least two sites working together. Having defined these sequences, we exploited this information to produce a simple system to investigate to what extent virions of HERV-Kcon, murine leukemia virus, and HIV-1 have the ability to transduce each other's genomes, leading to potential contamination of gene therapy vectors.
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105
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Goering W, Schmitt K, Dostert M, Schaal H, Deenen R, Mayer J, Schulz WA. Human endogenous retrovirus HERV-K(HML-2) activity in prostate cancer is dominated by a few loci. Prostate 2015; 75:1958-71. [PMID: 26384005 DOI: 10.1002/pros.23095] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 09/02/2015] [Indexed: 11/11/2022]
Abstract
BACKGROUND Increased expression of human endogenous retroviruses, especially HERV-K(HML-2) proviruses, has recently been associated with prostate carcinoma progression. In particular, a HML-2 locus in chromosome 22q11.23 (H22q) is upregulated in many cases. We therefore aimed at delineating the extent and repertoire of HML-2 transcription in prostate cancer tissues and cell lines and to define the transcription pattern and biological effects of H22q. METHODS Sanger and high throughput amplicon sequencing was used to define the repertoire of expressed HML-2 in a selected set of samples. qRT-PCR was used to quantify expression of selected proviruses in an extended set of prostate cancer tissues. Transcription factor binding sites (TFBS) were compared bioinformatically using the Transfac database. Expression of H22q was further characterized by siRNA-mediated knockdown, 5' RACE mapping of transcriptional start sites (TSS) and identification of splice sites. Functional effects of H22q knockdown were investigated by viability and apoptosis assays. RESULTS In addition to H22q, a limited number of other proviruses were found expressed by sequencing. Of these, provirus ERVK-5 and to a lesser degree ERVK-15 were frequently upregulated in prostate cancer. In contrast, expression of ERVK-24, predominant in germ cell tumors, was not detectable in prostatic tissues. While HML-2 LTRs contain binding sites for the androgen receptor and cofactors, no consistent differences in transcription factor binding sites were found between expressed and non-expressed proviruses. The H22q locus contains two 5'-LTRs of which the upstream LTR is predominantly used in prostatic cells, with an imprecise TSS. Splicing of H22q transcripts is complex, generating, among others, a transcript with an Np9-like ORF. Knockdown of H22q did not significantly affect proliferation or apoptosis of prostate cancer cells. CONCLUSIONS Our findings further underline that HML-2 expression is commonly highly tissue-specific. In prostate cancer, a limited number of loci become activated, especially H22q and ERVK-5. As expressed and non-expressed proviruses do not differ significantly in TFBS, tissue- and tumor-specific expression may be governed primarily by chromatin context. Overexpression of HML-2 H22q is more likely consequence than cause of prostate cancer progression.
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Affiliation(s)
- Wolfgang Goering
- Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Katja Schmitt
- Institute of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Melanie Dostert
- Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Heiner Schaal
- Institute of Virology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - René Deenen
- GTL, Biomedical Research Center, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jens Mayer
- Institute of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany
| | - Wolfgang A Schulz
- Department of Urology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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106
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Fava P, Bergallo M, Astrua C, Brizio M, Galliano I, Montanari P, Tovo PA, Novelli M, Savoia P, Quaglino P, Fierro MT. Human Endogenous Retrovirus Expression in Primary Cutaneous T-Cell Lymphomas. Dermatology 2015; 232:38-43. [DOI: 10.1159/000438669] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 07/12/2015] [Indexed: 11/19/2022] Open
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107
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Nadeau MJ, Manghera M, Douville RN. Inside the Envelope: Endogenous Retrovirus-K Env as a Biomarker and Therapeutic Target. Front Microbiol 2015; 6:1244. [PMID: 26617584 PMCID: PMC4643131 DOI: 10.3389/fmicb.2015.01244] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/26/2015] [Indexed: 11/27/2022] Open
Abstract
Due to multiple ancestral human retroviral germ cell infections, the modern human genome is strewn with relics of these infections, termed endogenous retroviruses (ERVs). ERV expression has been silenced due to negative selective pressures and genetic phenomena such as mutations and epigenetic silencing. Nonetheless, select ERVs have retained the capacity to be damaging to their host when reawakened. Much of the current research on the ERVK Env protein strongly suggests a causal or contributive role in the pathogenesis of various cancers, autoimmune and infectious diseases. Additionally, there is a small body of research suggesting that ERVK Env has been domesticated for use in placental development, akin to the ERVW syncytin. Though much is left to ascertain, the innate immune response to ERVK Env expression has been partially characterized and appears to be due to a region located in the transmembrane domain of the Env protein. In this review, we aim to highlight ERVK Env as a biomarker for inflammatory conditions and explore its use as a future therapeutic target for cancers, HIV infection and neurological disease.
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Affiliation(s)
- Marie-Josée Nadeau
- Douville Lab, Department of Biology, University of Winnipeg Winnipeg, MB, Canada
| | - Mamneet Manghera
- Douville Lab, Department of Biology, University of Winnipeg Winnipeg, MB, Canada ; Department of Immunology, University of Manitoba Winnipeg, MB, Canada
| | - Renée N Douville
- Douville Lab, Department of Biology, University of Winnipeg Winnipeg, MB, Canada ; Department of Immunology, University of Manitoba Winnipeg, MB, Canada
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108
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Suntsova M, Garazha A, Ivanova A, Kaminsky D, Zhavoronkov A, Buzdin A. Molecular functions of human endogenous retroviruses in health and disease. Cell Mol Life Sci 2015; 72:3653-75. [PMID: 26082181 PMCID: PMC11113533 DOI: 10.1007/s00018-015-1947-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 12/13/2022]
Abstract
Human endogenous retroviruses (HERVs) and related genetic elements form 504 distinct families and occupy ~8% of human genome. Recent success of high-throughput experimental technologies facilitated understanding functional impact of HERVs for molecular machinery of human cells. HERVs encode active retroviral proteins, which may exert important physiological functions in the body, but also may be involved in the progression of cancer and numerous human autoimmune, neurological and infectious diseases. The spectrum of related malignancies includes, but not limits to, multiple sclerosis, psoriasis, lupus, schizophrenia, multiple cancer types and HIV. In addition, HERVs regulate expression of the neighboring host genes and modify genomic regulatory landscape, e.g., by providing regulatory modules like transcription factor binding sites (TFBS). Indeed, recent bioinformatic profiling identified ~110,000 regulatory active HERV elements, which formed at least ~320,000 human TFBS. These and other peculiarities of HERVs might have played an important role in human evolution and speciation. In this paper, we focus on the current progress in understanding of normal and pathological molecular niches of HERVs, on their implications in human evolution, normal physiology and disease. We also review the available databases dealing with various aspects of HERV genetics.
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Affiliation(s)
- Maria Suntsova
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Laboratory of Bioinformatics, D. Rogachyov Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117198, Russia.
| | - Andrew Garazha
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Laboratory of Bioinformatics, D. Rogachyov Federal Research Center of Pediatric Hematology, Oncology and Immunology, Moscow, 117198, Russia.
| | - Alena Ivanova
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
| | - Dmitry Kaminsky
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
| | - Alex Zhavoronkov
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
- Department of Translational and Regenerative Medicine, Moscow Institute of Physics and Technology, 9 Institutskiy per., Dolgoprudny, Moscow, 141700, Russia.
| | - Anton Buzdin
- Group for Genomic Regulation of Cell Signaling Systems, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, 117997, Russia.
- Pathway Pharmaceuticals, Wan Chai, Hong Kong, Hong Kong SAR.
- National Research Centre "Kurchatov Institute", Centre for Convergence of Nano-, Bio-, Information and Cognitive Sciences and Technologies, 1, Akademika Kurchatova sq., Moscow, 123182, Russia.
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Abstract
This review explores the incessant evolutionary interaction and co-development between immune system evolution and somatic evolution, to put it into context with the short, over 60-year, detailed human study of this extraordinary protective system. Over millions of years, the evolutionary development of the immune system in most species has been continuously shaped by environmental interactions between microbes, and aberrant somatic cells, including malignant cells. Not only has evolution occurred in somatic cells to adapt to environmental pressures for survival purposes, but the immune system and its function has been successively shaped by those same evolving somatic cells and microorganisms through continuous adaptive symbiotic processes of progressive simultaneous immunological and somatic change to provide what we observe today. Indeed, the immune system as an environmental influence has also shaped somatic and microbial evolution. Although the immune system is tuned to primarily controlling microbiological challenges for combatting infection, it can also remove damaged and aberrant cells, including cancer cells to induce long-term cures. Our knowledge of how this occurs is just emerging. Here we consider the connections between immunity, infection and cancer, by searching back in time hundreds of millions of years to when multi-cellular organisms first began. We are gradually appreciating that the immune system has evolved into a truly brilliant and efficient protective mechanism, the importance of which we are just beginning to now comprehend. Understanding these aspects will likely lead to more effective cancer and other therapies.
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Affiliation(s)
- Brendon J Coventry
- Discipline of Surgery, Royal Adelaide Hospital, University of Adelaide, Adelaide, South Australia, 5000, Australia
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Unit, University of Adelaide, Adelaide, South Australia, 5005, Australia.,Institute of Evolutionary Medicine, The University of Zurich, 8057 Zurich, Switzerland
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110
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Abstract
This review explores the incessant evolutionary interaction and co-development between immune system evolution and somatic evolution, to put it into context with the short, over 60-year, detailed human study of this extraordinary protective system. Over millions of years, the evolutionary development of the immune system in most species has been continuously shaped by environmental interactions between microbes, and aberrant somatic cells, including malignant cells. Not only has evolution occurred in somatic cells to adapt to environmental pressures for survival purposes, but the immune system and its function has been successively shaped by those same evolving somatic cells and microorganisms through continuous adaptive symbiotic processes of progressive simultaneous immunological and somatic change to provide what we observe today. Indeed, the immune system as an environmental influence has also shaped somatic and microbial evolution. Although the immune system is tuned to primarily controlling microbiological challenges for combatting infection, it can also remove damaged and aberrant cells, including cancer cells to induce long-term cures. Our knowledge of how this occurs is just emerging. Here we consider the connections between immunity, infection and cancer, by searching back in time hundreds of millions of years to when multi-cellular organisms first began. We are gradually appreciating that the immune system has evolved into a truly brilliant and efficient protective mechanism, the importance of which we are just beginning to now comprehend. Understanding these aspects will likely lead to more effective cancer and other therapies.
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Affiliation(s)
- Brendon J Coventry
- Discipline of Surgery, Royal Adelaide Hospital, University of Adelaide, Adelaide, South Australia, 5000, Australia
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Unit, University of Adelaide, Adelaide, South Australia, 5005, Australia.,Institute of Evolutionary Medicine, The University of Zurich, 8057 Zurich, Switzerland
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111
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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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112
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Zhou F, Krishnamurthy J, Wei Y, Li M, Hunt K, Johanning GL, Cooper LJ, Wang-Johanning F. Chimeric antigen receptor T cells targeting HERV-K inhibit breast cancer and its metastasis through downregulation of Ras. Oncoimmunology 2015; 4:e1047582. [PMID: 26451325 DOI: 10.1080/2162402x.2015.1047582] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/27/2015] [Accepted: 04/29/2015] [Indexed: 12/15/2022] Open
Abstract
We have previously reported that human endogenous retrovirus-K (HERV-K) envelope (env) protein is a tumor-associated antigen (TAA) for cancer vaccines, and that its antibodies (mAbs) possess antitumor activity against cancer. In this study, a chimeric antigen receptor (CAR) specific for HERV-K env protein (K-CAR) was generated using anti-HERV-K mAb. K-CAR T cells from peripheral blood mononuclear cells (PBMCs) of 9 breast cancer (BC) patients and 12 normal donors were able to inhibit growth of, and to exhibit significant cytotoxicity toward, BC cells but not MCF-10A normal breast cells. The antitumor effects in cancer cells were significantly reduced when control T cells were used, or the expression of HERV-K was knocked down by an shRNA. Secretion of multiple cytokines, including IFNγ, TNF-α, and IL-2, was significantly enhanced in culture media of BC cells treated with K-CARs. Significantly reduced tumor growth and tumor weight was observed in xenograft models bearing MDA-MB-231 or MDA-MB-435.eB1 BC cells. Importantly, the K-CAR prevented tumor metastasis to other organs. Furthermore, downregulation of HERV-K expression in tumors of mice treated with K-CAR correlated with upregulation of p53 and downregulation of MDM2 and p-ERK. Importantly, the expression of HERV-K env protein in metastatic tumor tissues treated with K-CAR T cells correlated with the expression of Ras. Our results indicate that HERV-K env protein is an oncoprotein and may play an important role in tumorigenesis related to p53 and Ras signaling pathways. Anti-HERV-K treatment, including K-CAR treatment, shows potential for immunotherapy of BC.
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Affiliation(s)
- Fuling Zhou
- Department of Veterinary Sciences; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Viral Oncology Program; SRI International ; Menlo Park, CA USA ; Department of Clinical Hematology; Second Affiliated Hospital; School of Medicine; Xi'an Jiaotong University ; Xi'an, Shannxi, China
| | - Janani Krishnamurthy
- Division of Pediatrics; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Graduate School of Biomedical Sciences ; Houston, TX USA
| | - Yongchang Wei
- Department of Veterinary Sciences; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Viral Oncology Program; SRI International ; Menlo Park, CA USA ; Department of Clinical Oncology, First Affiliated Hospital; School of Medicine; Xi'an Jiaotong University , Xi'an, Shannxi, China
| | - Ming Li
- Department of Veterinary Sciences; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Viral Oncology Program; SRI International ; Menlo Park, CA USA ; Graduate School of Biomedical Sciences ; Houston, TX USA
| | - Kelly Hunt
- Department of Surgical Oncology; University of Texas MD Anderson Cancer Center ; Houston, TX USA
| | - Gary L Johanning
- Department of Veterinary Sciences; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Viral Oncology Program; SRI International ; Menlo Park, CA USA ; Graduate School of Biomedical Sciences ; Houston, TX USA
| | - Laurence Jn Cooper
- Division of Pediatrics; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Graduate School of Biomedical Sciences ; Houston, TX USA
| | - Feng Wang-Johanning
- Department of Veterinary Sciences; University of Texas MD Anderson Cancer Center ; Houston, TX USA ; Viral Oncology Program; SRI International ; Menlo Park, CA USA ; Graduate School of Biomedical Sciences ; Houston, TX USA ; Department of Immunology; University of Texas MD Anderson Cancer Center ; Houston, TX USA
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Macfarlane CM, Badge RM. Genome-wide amplification of proviral sequences reveals new polymorphic HERV-K(HML-2) proviruses in humans and chimpanzees that are absent from genome assemblies. Retrovirology 2015; 12:35. [PMID: 25927962 PMCID: PMC4422153 DOI: 10.1186/s12977-015-0162-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To date, the human population census of proviruses of the Betaretrovirus-like human endogenous retroviral (HERV-K) (HML-2) family has been compiled from a limited number of complete genomes, making it certain that rare polymorphic loci are under-represented and are yet to be described. RESULTS Here we describe a suppression PCR-based method called genome-wide amplification of proviral sequences (GAPS) that selectively amplifies DNA fragments containing the termini of HERV-K(HML-2) proviral sequences and their flanking genomic sequences. We analysed the HERV-K(HML-2) proviral content of 101 unrelated humans, 4 common chimpanzees and three centre d'etude du polymorphisme humain (CEPH) pedigrees (44 individuals). The technique isolated HERV-K(HML-2) proviruses that had integrated in the genomes of the great apes throughout their divergence and included evolutionarily young elements still unfixed for presence/absence. CONCLUSIONS By examining the HERV-K(HML-2) proviral content of 145 humans we detected a new insertionally polymorphic Type I HERV-K(HML-2) provirus. We also observed provirus versus solo long terminal repeat (LTR) polymorphism within humans at a previously unreported, but ancient, locus. Finally, we report two novel chimpanzee specific proviruses, one of which is dimorphic for a provirus versus solo LTR. Thus GAPS enables the isolation of uncharacterised HERV-K(HML-2) proviral sequences and provides a direct means to assess inter-individual genetic variation associated with HERV-K(HML-2) proviruses.
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Affiliation(s)
- Catriona M Macfarlane
- Department of Genetics, University of Leicester, University Road, Leicester, LE1 7RH, UK.
| | - Richard M Badge
- Department of Genetics, University of Leicester, University Road, Leicester, LE1 7RH, UK.
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Intrinsic retroviral reactivation in human preimplantation embryos and pluripotent cells. Nature 2015; 522:221-5. [PMID: 25896322 PMCID: PMC4503379 DOI: 10.1038/nature14308] [Citation(s) in RCA: 414] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 02/10/2015] [Indexed: 02/07/2023]
Abstract
Endogenous retroviruses (ERVs) are remnants of ancient retroviral infections, which comprise nearly 8% of the human genome1. The most recently acquired human ERV is HERV-K (HML-2), which repeatedly infected the primate lineage both before and after the divergence of humans and chimpanzees2,3. Unlike most other human ERVs, HERV-K retained multiple copies of intact open reading frames (ORFs) encoding retroviral proteins4. However, HERV-K is transcriptionally silenced by the host with exception of certain pathological contexts, such as germ cell tumors, melanoma, or HIV infection5–7. Here we demonstrate that DNA hypomethylation at LTR elements representing the most recent genomic integrations, together with transactivation by OCT4, synergistically facilitate HERV-K expression. Consequently, HERV-K is transcribed during normal human embryogenesis beginning with embryonic genome activation (EGA) at the 8-cell stage, continuing through the emergence of epiblast cells in pre-implantation blastocysts, and ceasing during hESC derivation from blastocyst outgrowths. Remarkably, HERV-K viral-like particles and Gag proteins are detected in human blastocysts, indicating that early human development proceeds in the presence of retroviral products. We further show that overexpression of one such product, HERV-K accessory protein Rec, in a pluripotent cell line is sufficient to increase IFITM1 levels on the cell surface and inhibit viral infection, suggesting at least one mechanism through which HERV-K can induce viral restriction pathways in early embryonic cells. Moreover, Rec directly binds a subset of cellular RNAs and modulates their ribosome occupancy, arguing that complex interactions between retroviral proteins and host factors can fine-tune regulatory properties of early human development.
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115
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Sokol M, Jessen KM, Pedersen FS. Human endogenous retroviruses sustain complex and cooperative regulation of gene-containing loci and unannotated megabase-sized regions. Retrovirology 2015; 12:32. [PMID: 25927889 PMCID: PMC4422309 DOI: 10.1186/s12977-015-0161-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/30/2015] [Indexed: 12/19/2022] Open
Abstract
Background Evidence suggests that some human endogenous retroviruses and endogenous retrovirus-like repeats (here collectively ERVs) regulate the expression of neighboring genes in normal and disease states; e.g. the human globin locus is regulated by an ERV9 that coordinates long-range gene switching during hematopoiesis and activates also intergenic transcripts. While complex transcription regulation is associated with integration of certain exogenous retroviruses, comparable regulation sustained by ERVs is less understood. Findings We analyzed ERV transcription using ERV9 consensus sequences and publically available RNA-sequencing, chromatin immunoprecipitation with sequencing (ChIP-seq) and cap analysis gene expression (CAGE) data from ENCODE. We discovered previously undescribed and advanced transcription regulation mechanisms in several human reference cell lines. We show that regulation by ERVs involves long-ranging activations including complex RNA splicing patterns, and transcription of large unannotated regions ranging in size from several hundred kb to around 1 Mb. Moreover, regulation was found to be cooperatively sustained in some loci by multiple ERVs and also non-LTR repeats. Conclusion Our analyses show that endogenous retroviruses sustain advanced transcription regulation in human cell lines, which shows similarities to complex insertional mutagenesis effects exerted by exogenous retroviruses. By exposing previously undescribed regulation effects, this study should prove useful for understanding fundamental transcription mechanisms resulting from evolutionary acquisition of retroviral sequence in the human genome. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0161-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martin Sokol
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
| | - Karen Margrethe Jessen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
| | - Finn Skou Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, DK-8000, Denmark.
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Kim WJ, Wittner BS, Amzallag A, Brannigan BW, Ting DT, Ramaswamy S, Maheswaran S, Haber DA. The WTX Tumor Suppressor Interacts with the Transcriptional Corepressor TRIM28. J Biol Chem 2015; 290:14381-90. [PMID: 25882849 DOI: 10.1074/jbc.m114.631945] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 02/05/2023] Open
Abstract
WTX encodes a tumor suppressor implicated in the pediatric kidney cancer Wilms tumor and in mesenchymal differentiation with potentially distinct functions in the cytoplasm, at the plasma membrane, and in the nucleus. Although modulating components of the WNT signaling pathway is a proposed function for cytoplasmic and membrane-bound WTX, its nuclear properties are not well understood. Here we report that the transcriptional corepressor TRIM28 is the major binding partner for nuclear WTX. WTX interacted with the coiled coil domain of TRIM28 required for its binding to Krüppel-associated box domains of transcription factors and for its chromatin recruitment through its own coiled coil and proline-rich domains. Knockdown of endogenous WTX reduced the recruitment of TRIM28 to a chromatinized reporter sequence and its ability to repress a target transcript. In mouse embryonic stem cells where TRIM28 plays a major role in repressing endogenous retroviruses and long interspersed elements, knockdown of either TRIM28 or WTX combined with single molecule RNA sequencing revealed a highly significant shared set of differentially regulated transcripts, including derepression of non-coding repetitive sequences and their neighboring protein encoding genes (p < 1e-20). In mesenchymal precursor cells, depletion of WTX and TRIM28 resulted in analogous β-catenin-independent defects in adipogenic and osteogenic differentiation, and knockdown of WTX reduced TRIM28 binding to Pparγ promoter. Together, the physical and functional interaction between WTX and TRIM28 suggests that the nuclear fraction of WTX plays a role in epigenetic silencing, an effect that may contribute to its function as a regulator of cellular differentiation and tumorigenesis.
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Affiliation(s)
- Woo Jae Kim
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Ben S Wittner
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Arnaud Amzallag
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - Brian W Brannigan
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and
| | - David T Ting
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and From the Departments of Medicine and
| | - Sridhar Ramaswamy
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and From the Departments of Medicine and
| | - Shyamala Maheswaran
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and Surgery
| | - Daniel A Haber
- Massachusetts General Hospital Cancer Center and Harvard Medical School, Charlestown, Massachusetts 02129 and From the Departments of Medicine and Howard Hughes Medical Institute, Chevy Chase, Maryland 20815
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117
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Doucet AJ, Droc G, Siol O, Audoux J, Gilbert N. U6 snRNA Pseudogenes: Markers of Retrotransposition Dynamics in Mammals. Mol Biol Evol 2015; 32:1815-32. [PMID: 25761766 PMCID: PMC4476161 DOI: 10.1093/molbev/msv062] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Transposable elements comprise more than 45% of the human genome and long interspersed nuclear element 1 (LINE-1 or L1) is the only autonomous mobile element remaining active. Since its identification, it has been proposed that L1 contributes to the mobilization and amplification of other cellular RNAs and more recently, experimental demonstrations of this function has been described for many transcripts such as Alu, a nonautonomous mobile element, cellular mRNAs, or small noncoding RNAs. Detailed examination of the mobilization of various cellular RNAs revealed distinct pathways by which they could be recruited during retrotransposition; template choice or template switching. Here, by analyzing genomic structures and retrotransposition signatures associated with small nuclear RNA (snRNA) sequences, we identified distinct recruiting steps during the L1 retrotransposition cycle for the formation of snRNA-processed pseudogenes. Interestingly, some of the identified recruiting steps take place in the nucleus. Moreover, after comparison to other vertebrate genomes, we established that snRNA amplification by template switching is common to many LINE families from several LINE clades. Finally, we suggest that U6 snRNA copies can serve as markers of L1 retrotransposition dynamics in mammalian genomes.
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Affiliation(s)
- Aurélien J Doucet
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institute for Research on Cancer and Aging, Nice (IRCAN), INSERM, U1081, CNRS UMR 7284, Nice, France
| | - Gaëtan Droc
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), UMR AGAP, Montpellier, France
| | - Oliver Siol
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France
| | - Jérôme Audoux
- Institute for Regenerative Medicine and Biotherapy, INSERM, U1183, Montpellier, France
| | - Nicolas Gilbert
- Institut de Génétique Humaine, CNRS, UPR 1142, Montpellier, France Institute for Regenerative Medicine and Biotherapy, INSERM, U1183, Montpellier, France
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Schmitt K, Heyne K, Roemer K, Meese E, Mayer J. HERV-K(HML-2) rec and np9 transcripts not restricted to disease but present in many normal human tissues. Mob DNA 2015; 6:4. [PMID: 25750667 PMCID: PMC4351823 DOI: 10.1186/s13100-015-0035-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/12/2015] [Indexed: 01/03/2023] Open
Abstract
Background Human endogenous retroviruses of the HERV-K(HML-2) group have been associated with the development of tumor diseases. Various HERV-K(HML-2) loci encode retrovirus-like proteins, and expression of such proteins is upregulated in certain tumor types. HERV-K(HML-2)-encoded Rec and Np9 proteins interact with functionally important cellular proteins and may contribute to tumor development. Though, the biological role of HERV-K(HML-2) transcription and encoded proteins in health and disease is less understood. We therefore investigated transcription specifically of HERV-K(HML-2) rec and np9 mRNAs in a panel of normal human tissues. Results We obtained evidence for rec and np9 mRNA being present in all examined 16 normal tissue types. A total of 18 different HERV-K(HML-2) loci were identified as generating rec or np9 mRNA, among them loci not present in the human reference genome and several of the loci harboring open reading frames for Rec or Np9 proteins. Our analysis identified additional alternative splicing events of HERV-K(HML-2) transcripts, some of them encoding variant Rec/Np9 proteins. We also identified a second HERV-K(HML-2) locus formed by L1-mediated retrotransposition that is likewise transcribed in various human tissues. Conclusions HERV-K(HML-2) rec and np9 transcripts from different HERV-K(HML-2) loci appear to be present in various normal human tissues. It is conceivable that Rec and Np9 proteins and variants of those proteins are part of the proteome of normal human tissues and thus various cell types. Transcription of HERV-K(HML-2) may thus also have functional relevance in normal human cell physiology. Electronic supplementary material The online version of this article (doi:10.1186/s13100-015-0035-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Katja Schmitt
- Institute of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, University of Saarland, 66424 Homburg/Saar, Germany ; Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, K703, Elisabeth Kuhn Street, Frankfurt/Main, 65926 Germany
| | - Kristina Heyne
- José Carreras Research Center, Medical Faculty, University of Saarland, 66424 Homburg/Saar, Germany
| | - Klaus Roemer
- José Carreras Research Center, Medical Faculty, University of Saarland, 66424 Homburg/Saar, Germany
| | - Eckart Meese
- Institute of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, University of Saarland, 66424 Homburg/Saar, Germany
| | - Jens Mayer
- Institute of Human Genetics, Center of Human and Molecular Biology, Medical Faculty, University of Saarland, 66424 Homburg/Saar, Germany ; Center of Human and Molecular Biology, University of Saarland, 66424 Homburg/Saar, Germany
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119
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Differential expression of HERV-K (HML-2) proviruses in cells and virions of the teratocarcinoma cell line Tera-1. Viruses 2015; 7:939-68. [PMID: 25746218 PMCID: PMC4379556 DOI: 10.3390/v7030939] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 02/09/2015] [Accepted: 02/19/2015] [Indexed: 01/12/2023] Open
Abstract
Human endogenous retrovirus (HERV-K (HML-2)) proviruses are among the few endogenous retroviral elements in the human genome that retain coding sequence. HML-2 expression has been widely associated with human disease states, including different types of cancers as well as with HIV-1 infection. Understanding of the potential impact of this expression requires that it be annotated at the proviral level. Here, we utilized the high throughput capabilities of next-generation sequencing to profile HML-2 expression at the level of individual proviruses and secreted virions in the teratocarcinoma cell line Tera-1. We identified well-defined expression patterns, with transcripts emanating primarily from two proviruses located on chromosome 22, only one of which was efficiently packaged. Interestingly, there was a preference for transcripts of recently integrated proviruses, over those from other highly expressed but older elements, to be packaged into virions. We also assessed the promoter competence of the 5’ long terminal repeats (LTRs) of expressed proviruses via a luciferase assay following transfection of Tera-1 cells. Consistent with the RNASeq results, we found that the activity of most LTRs corresponded to their transcript levels.
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120
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The effect of life history on retroviral genome invasions. PLoS One 2015; 10:e0117442. [PMID: 25692467 PMCID: PMC4333357 DOI: 10.1371/journal.pone.0117442] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 12/23/2014] [Indexed: 11/20/2022] Open
Abstract
Endogenous retroviruses (ERV), or the remnants of past retroviral infections that are no longer active, are found in the genomes of most vertebrates, typically constituting approximately 10% of the genome. In some vertebrates, particularly in shorter-lived species like rodents, it is not unusual to find active endogenous retroviruses. In longer-lived species, including humans where substantial effort has been invested in searching for active ERVs, it is unusual to find them; to date none have been found in humans. Presumably the chance of detecting an active ERV infection is a function of the length of an ERV epidemic. Intuitively, given that ERVs or signatures of past ERV infections are passed from parents to offspring, we might expect to detect more active ERVs in species with longer generation times, as it should take more years for an infection to run its course in longer than in shorter lived species. This means the observation of more active ERV infections in shorter compared to longer-lived species is paradoxical. We explore this paradox using a modeling approach to investigate factors that influence ERV epidemic length. Our simple epidemiological model may explain why we find evidence of active ERV infections in shorter rather than longer-lived species.
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121
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Transcriptional activity of human endogenous retroviruses in human peripheral blood mononuclear cells. BIOMED RESEARCH INTERNATIONAL 2015; 2015:164529. [PMID: 25734056 PMCID: PMC4334862 DOI: 10.1155/2015/164529] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/30/2014] [Accepted: 01/10/2015] [Indexed: 01/09/2023]
Abstract
Human endogenous retroviruses (HERVs) have been implicated in human physiology and in human pathology. A better knowledge of the retroviral transcriptional activity in the general population and during the life span would greatly help the debate on its pathologic potential. The transcriptional activity of four HERV families (H, K, W, and E) was assessed, by qualitative and quantitative PCR, in PBMCs from 261 individuals aged from 1 to 80 years. Our results show that HERV-H, HERV-K, and HERV-W, but not HERV-E, are transcriptionally active in the test population already in the early childhood. In addition, the transcriptional levels of HERV-H, HERV-K, and HERV-W change significantly during the life span, albeit with distinct patterns. Our results, reinforce the hypothesis of a physiological correlation between HERVs activity and the different stages of life in humans. Studies aiming at identifying the factors, which are responsible for these changes during the individual's life, are still needed. Although the observed phenomena are presumably subjected to great variability, the basal transcriptional activity of each individual, also depending on the different ages of life, must be carefully considered in all the studies involving HERVs as causative agents of disease.
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122
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Mensaert K, Van Criekinge W, Thas O, Schuuring E, Steenbergen RDM, Wisman GBA, De Meyer T. Mining for viral fragments in methylation enriched sequencing data. Front Genet 2015; 6:16. [PMID: 25699076 PMCID: PMC4316777 DOI: 10.3389/fgene.2015.00016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Accepted: 01/13/2015] [Indexed: 12/26/2022] Open
Abstract
Most next generation sequencing experiments generate more data than is usable for the experimental set up. For example, methyl-CpG binding domain (MBD) affinity purification based sequencing is often used for DNA-methylation profiling, but up to 30% of the sequenced fragments cannot be mapped uniquely to the reference genome. Here we present and evaluate a methodology for the identification of viruses in these otherwise unused paired-end MBD-seq data. Viral detection is accomplished by mapping non-reference alignable reads to a comprehensive set of viral genomes. As viruses play an important role in epigenetics and cancer development, 92 (pre)malignant and benign samples, originating from two different collections of cervical samples and related cell lines, were used in this study. These samples include primary carcinomas (n = 22), low- and high-grade cervical intraepithelial neoplasia (CIN1 and CIN2/3 - n = 2/n = 30) and normal tissue (n = 20), as well as control samples (n = 17). Viruses that were detected include phages, adenoviruses, herpesviridae and HPV. HPV, which causes virtually all cervical cancers, was identified in 95% of the carcinomas, 100% of the CIN2/3 samples, both CIN1 samples and in 55% of the normal samples. Comparing the amount of mapped fragments on HPV for each HPV-infected sample yielded a significant difference between normal samples and carcinomas or CIN2/3 samples (adjusted p-values resp. <10(-5), <10(-5)), reflecting different viral loads and/or methylation degrees in non-normal samples. Fragments originating from different HPV types could be distinguished and were independently validated by PCR-based assays in 71% of the detections. In conclusion, although limited by the a priori knowledge of viral reference genome sequences, the proposed methodology can provide a first confined but substantial insight into the presence, concentration and types of methylated viral sequences in MBD-seq data at low additional cost.
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Affiliation(s)
- Klaas Mensaert
- Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University Ghent, Belgium
| | - Wim Van Criekinge
- Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University Ghent, Belgium ; Department of Pathology, VU University Medical Center Amsterdam, Netherlands
| | - Olivier Thas
- Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University Ghent, Belgium
| | - Ed Schuuring
- Department of Pathology, Cancer Research Center Groningen, University of Groningen, University Medical Center Groningen Groningen, Netherlands
| | | | - G Bea A Wisman
- Department of Gynecologic Oncology, Cancer Research Center Groningen, University of Groningen, University Medical Center Groningen Groningen, Netherlands
| | - Tim De Meyer
- Department of Mathematical Modeling, Statistics and Bioinformatics, Ghent University Ghent, Belgium
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ERVK polyprotein processing and reverse transcriptase expression in human cell line models of neurological disease. Viruses 2015; 7:320-32. [PMID: 25609305 PMCID: PMC4306841 DOI: 10.3390/v7010320] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/02/2014] [Accepted: 01/12/2015] [Indexed: 12/03/2022] Open
Abstract
Enhanced expression of the reverse transcriptase (RT) protein encoded by human endogenous retrovirus-K (ERVK) is a promising biomarker for several inflammatory and neurological diseases. However, unlike RT enzymes encoded by exogenous retroviruses, little work has been done to identify ERVK RT isoforms, their expression patterns, and cellular localization. Using Western blot, we showcase the ERVK gag-pro-pol polyprotein processing leading to the production of several ERVK RT isoforms in human neuronal (ReNcell CX) and astrocytic (SVGA) models of neuroinflammatory disease. Since the pro-inflammatory cytokine IFNγ plays a key role in the pathology of several ERVK-associated neurological diseases, we sought to determine if IFNγ can drive ERVK RT expression. IFNγ signalling markedly enhanced ERVK polyprotein and RT expression in both human astrocytes and neurons. RT isoforms were expressed in a cell-type specific pattern and the RT-RNase H form was significantly increased with IFNγ treatment. Fluorescent imaging revealed distinct cytoplasmic, perinuclear and nuclear ERVK RT staining patterns upon IFNγ stimulation of astrocytes and neurons. These findings indicate that ERVK expression is inducible under inflammatory conditions such as IFNγ exposure—and thus, these newly established in vitro models may be useful in exploring ERVK biology in the context of neuroinflammatory disease.
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Nelson P, Rylance P, Roden D, Trela M, Tugnet N. Viruses as potential pathogenic agents in systemic lupus erythematosus. Lupus 2014; 23:596-605. [PMID: 24763543 DOI: 10.1177/0961203314531637] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Genetic and environmental factors appear to contribute to the pathogenesis of systemic lupus erythematosus (SLE). Viral infections have been reported to be associated with the disease. A number of exogenous viruses have been linked to the pathogenesis of SLE, of which Epstein-Barr virus (EBV) has the most evidence of an aetiological candidate. In addition, human endogenous retroviruses (HERV), HRES-1, ERV-3, HERV-E 4-1, HERV-K10 and HERV-K18 have also been implicated in SLE. HERVs are incorporated into human DNA, and thus can be inherited. HERVs may trigger an autoimmune reaction through molecular mimicry, since homology of amino acid sequences between HERV proteins and SLE autoantigens has been demonstrated. These viruses can also be influenced by oestrogen, DNA hypomethylation, and ultraviolet light (UVB) exposure which have been shown to enhance HERV activation or expression. Viral infection, or other environmental factors, could induce defective apoptosis, resulting in loss of immune tolerance. Further studies in SLE and other autoimmune diseases are needed to elucidate the contribution of both exogenous and endogenous viruses in the development of autoimmunity. If key peptide sequences could be identified as molecular mimics between viruses and autoantigens, then this might offer the possibility of the development of blocking peptides or antibodies as therapeutic agents in SLE and other autoimmune conditions.
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Affiliation(s)
- P Nelson
- 1Molecular Immunology Research Group, Research Institute in Healthcare Science, University of Wolverhampton, UK
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Antonelli G. From ‘purging’ to ‘endogenization’ of the HIV genome: a new approach to HIV eradication? Clin Microbiol Infect 2014; 20:1278-9. [DOI: 10.1111/1469-0691.12808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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126
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Nogueira MADS, Gavioli CFB, Pereira NZ, de Carvalho GC, Domingues R, Aoki V, Sato MN. Human endogenous retrovirus expression is inversely related with the up-regulation of interferon-inducible genes in the skin of patients with lichen planus. Arch Dermatol Res 2014; 307:259-64. [PMID: 25384438 DOI: 10.1007/s00403-014-1524-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 10/15/2014] [Accepted: 11/04/2014] [Indexed: 12/11/2022]
Abstract
Lichen planus (LP) is a common inflammatory skin disease of unknown etiology. Reports of a common transactivation of quiescent human endogenous retroviruses (HERVs) support the connection of viruses to the disease. HERVs are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancer and autoimmune diseases. We explored the transcriptional activity of HERV sequences as well as the antiviral restriction factor and interferon-inducible genes in the skin from LP patients and healthy control (HC) donors. The study included 13 skin biopsies from patients with LP and 12 controls. Real-time PCR assay identified significant decrease in the HERV-K gag and env mRNA expression levels in LP subjects, when compared to control group. The expressions of HERV-K18 and HERV-W env were also inhibited in the skin of LP patients. We observed a strong correlation between HERV-K gag with other HERV sequences, regardless the down-modulation of transcripts levels in LP group. In contrast, a significant up-regulation of the cytidine deaminase APOBEC 3G (apolipoprotein B mRNA-editing), and the GTPase MxA (Myxovirus resistance A) mRNA expression level was identified in the LP skin specimens. Other transcript expressions, such as the master regulator of type I interferon-dependent immune responses, STING (stimulator of interferon genes) and IRF-7 (interferon regulatory factor 7), IFN-β and the inflammassome NALP3, had increased levels in LP, when compared to HC group. Our study suggests that interferon-inducible factors, in addition to their role in innate immunity against exogenous pathogens, contribute to the immune control of HERVs. Evaluation of the balance between HERV and interferon-inducible factor expression could possibly contribute to surveillance of inflammatory/malignant status of skin diseases.
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127
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Bhardwaj N, Coffin JM. Endogenous retroviruses and human cancer: is there anything to the rumors? Cell Host Microbe 2014; 15:255-9. [PMID: 24629332 DOI: 10.1016/j.chom.2014.02.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Xenotropic murine leukemia virus-related virus (XMRV) infection was incorrectly associated with prostate cancer and chronic fatigue syndrome (CFS) in recent years. In this forum, we discuss the story of XMRV and how we can apply lessons learned here to inform the debate surrounding cancers associated with human endogenous retroviruses (HERVs).
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Affiliation(s)
- Neeru Bhardwaj
- Department of Molecular Biology and Microbiology, Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA
| | - John M Coffin
- Department of Molecular Biology and Microbiology, Graduate Program in Molecular Microbiology, Sackler School of Graduate Biomedical Sciences, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA.
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128
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The HERV-K human endogenous retrovirus envelope protein antagonizes Tetherin antiviral activity. J Virol 2014; 88:13626-37. [PMID: 25210194 DOI: 10.1128/jvi.02234-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Endogenous retroviruses are the remnants of past retroviral infections that are scattered within mammalian genomes. In humans, most of these elements are old degenerate sequences that have lost their coding properties. The HERV-K(HML2) family is an exception: it recently amplified in the human genome and corresponds to the most active proviruses, with some intact open reading frames and the potential to encode viral particles. Here, using a reconstructed consensus element, we show that HERV-K(HML2) proviruses are able to inhibit Tetherin, a cellular restriction factor that is active against most enveloped viruses and acts by keeping the viral particles attached to the cell surface. More precisely, we identify the Envelope protein (Env) as the viral effector active against Tetherin. Through immunoprecipitation experiments, we show that the recognition of Tetherin is mediated by the surface subunit of Env. Similar to Ebola glycoprotein, HERV-K(HML2) Env does not mediate Tetherin degradation or cell surface removal; therefore, it uses a yet-undescribed mechanism to inactivate Tetherin. We also assessed all natural complete alleles of endogenous HERV-K(HML2) Env described to date for their ability to inhibit Tetherin and found that two of them (out of six) can block Tetherin restriction. However, due to their recent amplification, HERV-K(HML2) elements are extremely polymorphic in the human population, and it is likely that individuals will not all possess the same anti-Tetherin potential. Because of Tetherin's role as a restriction factor capable of inducing innate immune responses, this could have functional consequences for individual responses to infection. IMPORTANCE Tetherin, a cellular protein initially characterized for its role against HIV-1, has been proven to counteract numerous enveloped viruses. It blocks the release of viral particles from producer cells, keeping them tethered to the cell surface. Several viruses have developed strategies to inhibit Tetherin activity, allowing them to efficiently infect and replicate in their host. Here, we show that human HERV-K(HML2) elements, the remnants of an ancient retroviral infection, possess an anti-Tetherin activity which is mediated by the envelope protein. It is likely that this activity was an important factor that contributed to the recent, human-specific amplification of this family of elements. Also, due to their recent amplification, HERV-K(HML2) elements are highly polymorphic in the human population. Since Tetherin is a mediator of innate immunity, interindividual variations among HERV-K(HML2) Env genes may result in differences in immune responses to infection.
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129
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Distinct isoform of FABP7 revealed by screening for retroelement-activated genes in diffuse large B-cell lymphoma. Proc Natl Acad Sci U S A 2014; 111:E3534-43. [PMID: 25114248 DOI: 10.1073/pnas.1405507111] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Remnants of ancient transposable elements (TEs) are abundant in mammalian genomes. These sequences harbor multiple regulatory motifs and hence are capable of influencing expression of host genes. In response to environmental changes, TEs are known to be released from epigenetic repression and to become transcriptionally active. Such activation could also lead to lineage-inappropriate activation of oncogenes, as one study described in Hodgkin lymphoma. However, little further evidence for this mechanism in other cancers has been reported. Here, we reanalyzed whole transcriptome data from a large cohort of patients with diffuse large B-cell lymphoma (DLBCL) compared with normal B-cell centroblasts to detect genes ectopically expressed through activation of TE promoters. We have identified 98 such TE-gene chimeric transcripts that were exclusively expressed in primary DLBCL cases and confirmed several in DLBCL-derived cell lines. We further characterized a TE-gene chimeric transcript involving a fatty acid-binding protein gene (LTR2-FABP7), normally expressed in brain, that was ectopically expressed in a subset of DLBCL patients through the use of an endogenous retroviral LTR promoter of the LTR2 family. The LTR2-FABP7 chimeric transcript encodes a novel chimeric isoform of the protein with characteristics distinct from native FABP7. In vitro studies reveal a dependency for DLBCL cell line proliferation and growth on LTR2-FABP7 chimeric protein expression. Taken together, these data demonstrate the significance of TEs as regulators of aberrant gene expression in cancer and suggest that LTR2-FABP7 may contribute to the pathogenesis of DLBCL in a subgroup of patients.
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Wallace TA, Downey RF, Seufert CJ, Schetter A, Dorsey TH, Johnson CA, Goldman R, Loffredo CA, Yan P, Sullivan FJ, Giles FJ, Wang-Johanning F, Ambs S, Glynn SA. Elevated HERV-K mRNA expression in PBMC is associated with a prostate cancer diagnosis particularly in older men and smokers. Carcinogenesis 2014; 35:2074-83. [PMID: 24858205 DOI: 10.1093/carcin/bgu114] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Aberrant expression of subgroup k human endogenous retroviruses (HERV-K) has been observed in prostate cancer. This subgroup is unique because it encodes sequences in the human genome containing open reading frames for near intact retroviruses. We hypothesized that HERV-K reactivation could serve as a non-invasive early disease detection marker for prostate cancer. We evaluated HERV-K gag messenger RNA (mRNA) expression in blood samples of African-American and European-American men using a case-control design via quantitative real-time PCR. Additionally, we examined HERV-K envelope protein expression in prostate tumors by immunohistochemistry. HERV-K envelope protein was commonly upregulated in prostate tumors, but more so in tumors of African-American than European-American patients (61% versus 40%, P < 0.01). Examining HERV-K gag expression in peripheral blood mononuclear cells (PBMC) from 294 cases and 135 healthy men, we found that the abundance of HERV-K gag message was significantly higher in cases than controls and was associated with increased plasma interferon-γ. Men with gag expression in the highest quartile had >12-fold increased odds {odds ratio = 12.87 [95% confidence interval 6.3-26.25]} of being diagnosed with prostate cancer than those in the lowest quartile. Moreover, our results showed that HERV-K expression may perform better as a disease biomarker in older than younger men (whereas the sensitivity of prostate-specific antigen (PSA) testing decreases with age) and in men with a smoking history compared with never smokers. Combining non-invasive HERV-K testing with PSA testing may improve the efficacy of prostate cancer detection specifically among older men and smokers who tend to develop a more aggressive disease.
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Affiliation(s)
- Tiffany A Wallace
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA, Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA, Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Ronan F Downey
- Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland
| | - Caleb J Seufert
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA, Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA, Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Aaron Schetter
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA, Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA, Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Tiffany H Dorsey
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA, Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA, Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Carol A Johnson
- Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland
| | - Radoslav Goldman
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA
| | - Christopher A Loffredo
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA
| | - Peisha Yan
- Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Francis J Sullivan
- Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and
| | - Francis J Giles
- Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland
| | - Feng Wang-Johanning
- Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Stefan Ambs
- Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA, Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland, Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057-1465, USA, Department of Pathology and Laboratory Medicine, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA, Department of Radiation Oncology, Galway University Hospital, Galway, Ireland and Viral Oncology, Center for Cancer and Metabolism, Stanford Research Institute International, Menlo Park, CA 94025, USA
| | - Sharon A Glynn
- Prostate Cancer Institute, Biosciences Research Building, National University of Ireland Galway, Dangan, Corrib Village, Galway, Ireland,
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Mason MJ, Speake C, Gersuk VH, Nguyen QA, O'Brien KK, Odegard JM, Buckner JH, Greenbaum CJ, Chaussabel D, Nepom GT. Low HERV-K(C4) copy number is associated with type 1 diabetes. Diabetes 2014; 63:1789-95. [PMID: 24430436 DOI: 10.2337/db13-1382] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Complement component C4 (C4) is a highly variable complement pathway gene situated ∼500 kb from DRB1 and DQB1, the genes most strongly associated with many autoimmune diseases. Variations in C4 copy number (CN), length, and isotype create a highly diverse gene cluster in which insertion of an endogenous retrovirus in the ninth intron of C4, termed HERV-K(C4), is a notable component. We investigated the relationship between C4 variation/CN and type 1 diabetes. We found that individuals with type 1 diabetes have significantly fewer copies of HERV-K(C4) and that this effect is not solely due to linkage with known major histocompatibility complex class II susceptibility alleles. We show that HERV-K(C4) is a novel marker of type 1 diabetes that accounts for the disease association previously attributed to some key HLA-DQB1 alleles, raising the possibility that this retroviral insertion element contributes to functional protection against type 1 diabetes.
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Affiliation(s)
- Mike J Mason
- Systems Immunology, Benaroya Research Institute, Seattle, WA
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Katoh I. Impacts of endogenous retroviruses on tumorigenesis, immunity, stem cells, and research safety. Front Oncol 2014; 4:66. [PMID: 24744991 PMCID: PMC3978315 DOI: 10.3389/fonc.2014.00066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 03/19/2014] [Indexed: 12/01/2022] Open
Affiliation(s)
- Iyoko Katoh
- Molecular Biology, Center for Medical Education and Sciences, University of Yamanashi , Yamanashi , Japan
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Trans-activation, post-transcriptional maturation, and induction of antibodies to HERV-K (HML-2) envelope transmembrane protein in HIV-1 infection. Retrovirology 2014; 11:10. [PMID: 24472118 PMCID: PMC3907665 DOI: 10.1186/1742-4690-11-10] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 01/07/2014] [Indexed: 12/22/2022] Open
Abstract
Background Human Endogenous Retroviruses (HERVs) comprise about 8% of the human genome and have lost their ability to replicate or to produce infectious particles after having accumulated mutations over time. We assessed the kinetics of expression of HERV-K (HML-2) Envelope mRNA transcript and surface unit (SU) and transmembrane (TM) subunit proteins during HIV-1 infection. We also mapped the specificity of the humoral response to HERV-K (HML-2) Envelope protein in HIV-1 infected subjects at different stages of disease, and correlated the response with plasma viral load. Results We found that HIV-1 modified HERV-K (HML-2) Env mRNA expression, resulting in the expression of a fully N-glycosylated HERV-K (HML-2) envelope protein on the cell surface. Serological mapping of HERV-K (HML-2) envelope protein linear epitopes revealed two major immunogenic domains, one on SU and another on the ectodomain of TM. The titers of HERV-K (HML-2) TM antibodies were dramatically increased in HIV-1 infected subjects (p < 0.0001). HIV-1 infected adults who control HIV-1 in the absence of therapy (“elite” controllers) had a higher titer response against TM compared to antiretroviral-treated adults (p < 0.0001) and uninfected adults (p < 0.0001). Conclusions These data collectively suggest that HIV-1 infection induces fully glycosylated HERV-K (HML-2) envelope TM protein to which antibodies are induced. These anti-HERV-K (HML-2) TM antibodies are a potential marker of HIV-1 infection, and are at higher titer in elite controllers. HERV-K (HML-2) envelope TM protein may be a new therapeutic target in HIV-1 infection.
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