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Chisca M, Larouche JD, Xing Q, Kassiotis G. Antibodies against endogenous retroviruses. Immunol Rev 2024. [PMID: 39152687 DOI: 10.1111/imr.13378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2024]
Abstract
The human genome harbors hundreds of thousands of integrations of ancient retroviruses, amassed over millions of years of evolution. To reduce further amplification in the genome, the host prevents transcription of these now endogenous retroviruses (ERVs) through epigenetic repression and, with evolutionary time, ERVs are incapacitated by accumulating mutations and deletions. However, several members of recently endogenized ERV groups still retain the capacity to produce viral RNA, retroviral proteins, and higher order structures, including virions. The retention of viral characteristics, combined with the reversible nature of epigenetic repression, particularly as seen in cancer, allow for immunologically unanticipated ERV expression, perceived by the adaptive immune system as a genuine retroviral infection, to which it has to respond. Accordingly, antibodies reactive with ERV antigens have been detected in diverse disorders and, occasionally, in healthy individuals. Although they are part of self, the retroviral legacy of ERV antigens, and association with and, possibly, causation of disease states may set them apart from typical self-antigens. Consequently, the pathogenic or, indeed, host-protective capacity of antibodies targeting ERV antigens is likely to be context-dependent. Here, we review the immunogenicity of typical ERV proteins, with emphasis on the antibody response and its potential disease implications.
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Affiliation(s)
- Mihaela Chisca
- Retroviral Immunology Laboratory, The Francis Crick Institute, London, UK
| | | | - Qi Xing
- Retroviral Immunology Laboratory, The Francis Crick Institute, London, UK
| | - George Kassiotis
- Retroviral Immunology Laboratory, The Francis Crick Institute, London, UK
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
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2
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Bo M, Manetti R, Biggio ML, Sechi LA. The Humoral Immune Response against Human Endogenous Retroviruses in Celiac Disease: A Case-Control Study. Biomedicines 2024; 12:1811. [PMID: 39200275 PMCID: PMC11351412 DOI: 10.3390/biomedicines12081811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 07/30/2024] [Accepted: 08/07/2024] [Indexed: 09/02/2024] Open
Abstract
BACKGROUND Celiac disease (CD) is an immune-mediated disease characterized by disruptions of the small intestine. Factors such as viral and bacterial infections can trigger CD. Recently, the reactivation of Human Endogenous Retroviruses (HERVs) has also been implicated, but little is known about their specific role in patients with celiac disease. METHODS The purpose of this study is to explore the humoral immune response mounted against epitopes derived from the envelope portion of three families of HERVs (HERV-K, HERV-H, and HERV-W) in CD patients. Reactivity against the HERV-K, HERV-H, and HERV-W env-su peptides was tested by indirect ELISAs in plasma of 40 patients with celiac disease and 41 age-matched healthy subjects (HCs). RESULTS HERV-K, HERV-H, and HERV-W env-su peptides triggered different antibody responses in CD patients compared to HCs, with a stronger reactivity (p = 0.0001). CONCLUSIONS Present results show, for the first time, that epitopes of HERV-K, HERV-H, and HERV-W are more recognized in patients with CD. Taking into consideration their proinflammatory and autoimmune features, this might suggest that HERVs may contribute to the development of CD or its exacerbation in genetically predisposed subjects. Finally, to elucidate the interplay between gut inflammation and HERVs during the inflammatory process, further studies are required. Those investigations should focus on the expression levels of HERVs and their relationship with the immune response, specifically examining anti-transglutaminase 2 (TG2) antibody levels under both gluten-free and gluten-containing dietary conditions.
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Affiliation(s)
- Marco Bo
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Sassari, Viale San Pietro 43b, 07100 Sassari, Italy;
- Struttura Complessa Microbiologia e Virologia, Azienda Ospedaliera Universitaria Sassari, 07100 Sassari, Italy
| | - Roberto Manetti
- Department of Medicine, Surgery and Pharmacology, University of Sassari, 07100 Sassari, Italy; (R.M.)
| | - Maria Luigia Biggio
- Department of Medicine, Surgery and Pharmacology, University of Sassari, 07100 Sassari, Italy; (R.M.)
| | - Leonardo A. Sechi
- Department of Biomedical Sciences, Section of Microbiology and Virology, University of Sassari, Viale San Pietro 43b, 07100 Sassari, Italy;
- Struttura Complessa Microbiologia e Virologia, Azienda Ospedaliera Universitaria Sassari, 07100 Sassari, Italy
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3
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Dai YD, Du W, Wang Y, Hu WY. A Targeted Deep Sequencing Method to Quantify Endogenous Retrovirus Gag Sequence Variants and Open Reading Frames Expressed in Nonobese Diabetic Mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2024; 213:15-22. [PMID: 38738929 DOI: 10.4049/jimmunol.2300660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 04/22/2024] [Indexed: 05/14/2024]
Abstract
Endogenous retroviruses (ERVs) are involved in autoimmune diseases such as type 1 diabetes (T1D). ERV gene products homologous to murine leukemia retroviruses are expressed in the pancreatic islets of NOD mice, a model of T1D. One ERV gene, Gag, with partial or complete open reading frames (ORFs), is detected in the islets, and it contains many sequence variants. An amplicon deep sequencing analysis was established by targeting a conserved region within the Gag gene to compare NOD with T1D-resistant mice or different ages of prediabetic NOD mice. We observed that the numbers of different Gag variants and ORFs are linked to T1D susceptibility. More importantly, these numbers change during the course of diabetes development and can be quantified to calculate the levels of disease progression. Sequence alignment analysis led to identification of additional markers, including nucleotide mismatching and amino acid consensus at specific positions that can distinguish the early and late stages, before diabetes onset. Therefore, the expression of sequence variants and ORFs of ERV genes, particularly Gag, can be quantified as biomarkers to estimate T1D susceptibility and disease progression.
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Affiliation(s)
- Yang D Dai
- Biomedical Research Institute of Southern California, Oceanside, CA
- HERV Laboratory, San Diego, CA
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4
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Mantovani F, Kitsou K, Magiorkinis G. HERVs: Expression Control Mechanisms and Interactions in Diseases and Human Immunodeficiency Virus Infection. Genes (Basel) 2024; 15:192. [PMID: 38397182 PMCID: PMC10888493 DOI: 10.3390/genes15020192] [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: 12/22/2023] [Revised: 01/24/2024] [Accepted: 01/27/2024] [Indexed: 02/25/2024] Open
Abstract
Human endogenous retroviruses (HERVs) are the result of retroviral infections acquired millions of years ago; nowadays, they compose around 8% of human DNA. Multiple mechanisms have been employed for endogenous retroviral deactivation, rendering replication and retrotransposition defective, while some of them have been co-opted to serve host evolutionary advantages. A pleiad of mechanisms retains the delicate balance of HERV expression in modern humans. Thus, epigenetic modifications, such as DNA and histone methylation, acetylation, deamination, chromatin remodeling, and even post-transcriptional control are recruited. In this review, we aim to summarize the main HERV silencing pathways, revisit paradigms of human disease with a HERV component, and emphasize the human immunodeficiency virus (HIV) and HERV interactions during HIV infection.
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Affiliation(s)
| | | | - Gkikas Magiorkinis
- Department of Hygiene, Epidemiology and Medical Statistics, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece; (F.M.); (K.K.)
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5
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Laine A, Wang X, Ni K, Smith SEB, Najjar R, Whitmore LS, Yacoub M, Bays A, Gale M, Mustelin T. Expression of Envelope Protein Encoded by Endogenous Retrovirus K102 in Rheumatoid Arthritis Neutrophils. Microorganisms 2023; 11:1310. [PMID: 37317284 PMCID: PMC10223813 DOI: 10.3390/microorganisms11051310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/13/2023] [Accepted: 05/14/2023] [Indexed: 06/16/2023] Open
Abstract
Many patients suffering from autoimmune diseases have autoantibodies against proteins encoded by genomic retroelements, suggesting that normal epigenetic silencing is insufficient to prevent the production of the encoded proteins for which immune tolerance appears to be limited. One such protein is the transmembrane envelope (Env) protein encoded by human endogenous retrovirus K (HERV-K). We reported recently that patients with rheumatoid arthritis (RA) have IgG autoantibodies that recognize Env. Here, we use RNA sequencing of RA neutrophils to analyze HERV-K expression and find that only two loci with an intact open-reading frame for Env, HERV-K102, and K108 are expressed, but only the former is increased in RA. In contrast, other immune cells express more K108 than K102. Patient autoantibodies recognized endogenously expressed Env in breast cancer cells and in RA neutrophils but not healthy controls. A monoclonal anti-Env antibody also detected Env on the surface of RA neutrophils but very little on the surface of other immune cells. We conclude that HERV-K102 is the locus that produces Env detectable on the surface of neutrophils in RA. The low levels of HERV-K108 transcripts may contribute only marginally to cell surface Env on neutrophils or other immune cells in some patients.
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Affiliation(s)
- Amanda Laine
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Xiaoxing Wang
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Kathryn Ni
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Sarah E. B. Smith
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Rayan Najjar
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Leanne S. Whitmore
- Center for Innate Immunity and Infectious Disease, Department of Immunology, University of Washington, Seattle, WA 98195, USA
| | - Michael Yacoub
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Alison Bays
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Michael Gale
- Center for Innate Immunity and Infectious Disease, Department of Immunology, University of Washington, Seattle, WA 98195, USA
| | - Tomas Mustelin
- Division of Rheumatology, Department of Medicine, University of Washington, Seattle, WA 98195, USA
- Center for Innate Immunity and Infectious Disease, Department of Immunology, University of Washington, Seattle, WA 98195, USA
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6
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Alcazer V, Bonaventura P, Tonon L, Michel E, Mutez V, Fabres C, Chuvin N, Boulos R, Estornes Y, Maguer-Satta V, Geistlich K, Viari A, Metzeler KH, Hiddemann W, Batch AMN, Herold T, Caux C, Depil S. HERVs characterize normal and leukemia stem cells and represent a source of shared epitopes for cancer immunotherapy. Am J Hematol 2022; 97:1200-1214. [PMID: 35759575 PMCID: PMC9540360 DOI: 10.1002/ajh.26647] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/21/2022] [Accepted: 06/21/2022] [Indexed: 11/06/2022]
Abstract
Human endogenous retroviruses (HERVs) represent 8% of the human genome. The expression of HERVs and their immune impact have not been extensively studied in Acute Myeloid Leukemia (AML). In this study, we used a reference of 14,968 HERV functional units to provide a thorough analysis of HERV expression in normal and AML bone marrow cells. We show that the HERV retrotranscriptome accurately characterizes normal and leukemic cell subpopulations, including leukemia stem cells, in line with different epigenetic profiles. We then show that HERV expression delineates AML subtypes with different prognoses. We finally propose a method to select and prioritize CD8+ T cell epitopes derived from AML-specific HERVs and we show that lymphocytes infiltrating patient bone marrow at diagnosis contain naturally occurring CD8+ T cells against these HERV epitopes. We also provide in vitro data supporting the functionality of HERV-specific CD8+ T-cells against AML cells. These results show that HERVs represent an important source of genetic information that can help enhancing disease stratification or biomarker identification and an important reservoir of alternative tumor-specific T cell epitopes relevant for cancer immunotherapy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Vincent Alcazer
- Department of Hematology, Hospices Civils de Lyon, Lyon Sud Hospital, Pierre-Bénite, France.,Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France
| | - Paola Bonaventura
- Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Laurie Tonon
- Synergie Lyon Cancer Foundation, Gilles Thomas Bioinformatics Center, Centre Léon Bérard, Lyon, France
| | - Emilie Michel
- Ervaccine Technologies, Centre Leon Bérard, Lyon, France
| | - Virginie Mutez
- Ervaccine Technologies, Centre Leon Bérard, Lyon, France
| | - Clémentine Fabres
- Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Nicolas Chuvin
- Ervaccine Technologies, Centre Leon Bérard, Lyon, France
| | - Rasha Boulos
- Ervaccine Technologies, Centre Leon Bérard, Lyon, France
| | - Yann Estornes
- Ervaccine Technologies, Centre Leon Bérard, Lyon, France
| | | | - Kevin Geistlich
- Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France
| | - Alain Viari
- Synergie Lyon Cancer Foundation, Gilles Thomas Bioinformatics Center, Centre Léon Bérard, Lyon, France
| | - Klaus H Metzeler
- Laboratory for Leukemia Diagnostics, Department of Medicine III, University Hospital, LMU Munich, Munich, Germany.,Dept. of Hematology and Cell Therapy, University of Leipzig, Leipzig, Germany
| | - Wolfgang Hiddemann
- Laboratory for Leukemia Diagnostics, Department of Medicine III, University Hospital, LMU Munich, Munich, Germany
| | - Aarif M N Batch
- Institute of Medical Data Processing, Biometrics and Epidemiology (IBE), Faculty of Medicine, LMU Munich, Munich, Germany.,Data Integration for Future Medicine (DiFuture, www.difuture.de), LMU Munich, Munich, Germany
| | - Tobias Herold
- Laboratory for Leukemia Diagnostics, Department of Medicine III, University Hospital, LMU Munich, Munich, Germany
| | - Christophe Caux
- Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Stéphane Depil
- Cancer Research Center of Lyon, INSERM U1052 and CNRS UMR5286, Lyon, France.,Ervaccine Technologies, Centre Leon Bérard, Lyon, France.,Centre Léon Bérard, Lyon, France.,University Claude Bernard Lyon 1, Lyon, France
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7
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Liu X, Ding Y, Zheng X, Huang H, Shi L, Yang X, Wei J, Li Y, Kao W, Zhang F, Qian J. Small RNAs encoded by human endogenous retrovirus K overexpressed in PBMCs may contribute to the diagnosis and evaluation of systemic lupus erythematosus as novel biomarkers. Hum Mol Genet 2021; 31:1407-1416. [PMID: 34761271 DOI: 10.1093/hmg/ddab327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/09/2021] [Accepted: 11/03/2021] [Indexed: 11/13/2022] Open
Abstract
This study aimed to identify the genes and small RNAs (sRNAs) expressed by the human endogenous retrovirus K (HERV-K) HML2 and their associations with the immune process of systemic lupus erythematosus (SLE). RNA-Seq data including 99 SLE patients and 18 controls (GSE72420) was obtained from the Gene Expression Omnibus. Differentially expressed genes (DEGs) as well as HML2-DEGs between SLE patients and normal controls were identified. Five HML2-DEGs involved in immune-regulating function were identified using weighted gene co-expression network analysis (WGCNA). The associations between these genes and the proportions of immune cells were determined by CIBERSORT. Ten candidate HML2-encoded sRNAs were identified based on specific criteria, and three of them were further validated in SLE patients by qRT-PCR. The diagnostic values of these three sRNAs were evaluated in SLE and lupus nephritis (LN). This study suggested that HML2 genes and their encoded sRNAs might be involved in the immune regulation and progress of SLE. These potential sRNAs might function as regulatory molecules and diagnostic biomarkers of SLE and LN.
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Affiliation(s)
- Xinyi Liu
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Yanjun Ding
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Xiaoqiu Zheng
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - He Huang
- Department of Rheumatology and Immunology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, China
| | - Liyu Shi
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Xiaolan Yang
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Jing Wei
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Yang Li
- Department of Rheumatology and Immunology, The Second Affiliated Hospital of Harbin Medical University, Harbin, 150001, China
| | - Wenping Kao
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Fengmin Zhang
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
| | - Jun Qian
- Wu Lien-Teh Institute, Department of Microbiology, Harbin Medical University, Harbin, 150081, China.,Heilongjiang Provincial Key Laboratory of Infection and Immunity, Pathogen Biology, Harbin, 150081, China
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8
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Römer C. Viruses and Endogenous Retroviruses as Roots for Neuroinflammation and Neurodegenerative Diseases. Front Neurosci 2021; 15:648629. [PMID: 33776642 PMCID: PMC7994506 DOI: 10.3389/fnins.2021.648629] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Accepted: 02/05/2021] [Indexed: 12/15/2022] Open
Abstract
Many neurodegenerative diseases are associated with chronic inflammation in the brain and periphery giving rise to a continuous imbalance of immune processes. Next to inflammation markers, activation of transposable elements, including long intrespersed nuclear elements (LINE) elements and endogenous retroviruses (ERVs), has been identified during neurodegenerative disease progression and even correlated with the clinical severity of the disease. ERVs are remnants of viral infections in the human genome acquired during evolution. Upon activation, they produce transcripts and the phylogenetically youngest ones are still able to produce viral-like particles. In addition, ERVs can bind transcription factors and modulate immune response. Being between own and foreign, ERVs are reviewed in the context of viral infections of the central nervous system, in aging and neurodegenerative diseases. Moreover, this review tests the hypothesis that viral infection may be a trigger at the onset of neuroinflammation and that ERVs sustain the inflammatory imbalance by summarizing existing data of neurodegenerative diseases associated with viruses and/or ERVs.
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Affiliation(s)
- Christine Römer
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, The Berlin Institute for Medical Systems Biology, Berlin, Germany
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9
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Gröger V, Wieland L, Naumann M, Meinecke AC, Meinhardt B, Rossner S, Ihling C, Emmer A, Staege MS, Cynis H. Formation of HERV-K and HERV-Fc1 Envelope Family Members is Suppressed on Transcriptional and Translational Level. Int J Mol Sci 2020; 21:ijms21217855. [PMID: 33113941 PMCID: PMC7660216 DOI: 10.3390/ijms21217855] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/15/2020] [Accepted: 10/21/2020] [Indexed: 12/12/2022] Open
Abstract
The human genome comprises 8% sequences of retroviral origin, so-called human endogenous retroviruses (HERVs). Most of these proviral sequences are defective, but some possess open reading frames. They can lead to the formation of viral transcripts, when activated by intrinsic and extrinsic factors. HERVs are thought to play a pathological role in inflammatory diseases and cancer. Since the consequences of activated proviral sequences in the human body are largely unexplored, selected envelope proteins of human endogenous retroviruses associated with inflammatory diseases, namely HERV-K18, HERV-K113, and HERV-Fc1, were investigated in the present study. A formation of glycosylated envelope proteins was demonstrated in different mammalian cell lines. Nevertheless, protein maturation seemed to be incomplete as no transport to the plasma membrane was observed. Instead, the proteins remained in the ER where they induced the expression of genes involved in unfolded protein response, such as HSPA5 and sXBP1. Furthermore, low expression levels of native envelope proteins were increased by codon optimization. Cell-free expression systems showed that both the transcriptional and translational level is affected. By generating different codon-optimized variants of HERV-K113 envelope, the influence of single rare t-RNA pools in certain cell lines was demonstrated. The mRNA secondary structure also appears to play an important role in the translation of the tested viral envelope proteins. In summary, the formation of certain HERV proteins is basically possible. However, their complete maturation and thus full biologic activity seems to depend on additional factors that might be disease-specific and await elucidation in the future.
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Affiliation(s)
- Victoria Gröger
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Weinbergweg 22, 06120 Halle, Germany; (V.G.); (M.N.); (A.-C.M.)
| | - Lisa Wieland
- Department of Neurology, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany; (L.W.); (B.M.); (A.E.)
- Department of Surgical and Conservative Pediatrics and Adolescent Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany
| | - Marcel Naumann
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Weinbergweg 22, 06120 Halle, Germany; (V.G.); (M.N.); (A.-C.M.)
| | - Ann-Christin Meinecke
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Weinbergweg 22, 06120 Halle, Germany; (V.G.); (M.N.); (A.-C.M.)
| | - Beate Meinhardt
- Department of Neurology, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany; (L.W.); (B.M.); (A.E.)
- Department of Surgical and Conservative Pediatrics and Adolescent Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany
| | - Steffen Rossner
- Paul Flechsig Institute for Brain Research, Leipzig University, Liebigstraße 19, 04103 Leipzig, Germany;
| | - Christian Ihling
- Department of Pharmaceutical Chemistry & Bioanalytics, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, Kurt-Mothes-Str. 3a, 06120 Halle, Germany;
| | - Alexander Emmer
- Department of Neurology, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany; (L.W.); (B.M.); (A.E.)
| | - Martin S. Staege
- Department of Surgical and Conservative Pediatrics and Adolescent Medicine, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06097 Halle, Germany
- Correspondence: (M.S.S.); (H.C.); Tel.: +49-345-5577280 (M.S.S.); +49-345-13142835 (H.C.); Fax: +49-345-5577275 (M.S.S.); +49-345-13142801 (H.C.)
| | - Holger Cynis
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Weinbergweg 22, 06120 Halle, Germany; (V.G.); (M.N.); (A.-C.M.)
- Correspondence: (M.S.S.); (H.C.); Tel.: +49-345-5577280 (M.S.S.); +49-345-13142835 (H.C.); Fax: +49-345-5577275 (M.S.S.); +49-345-13142801 (H.C.)
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10
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Panova V, Attig J, Young GR, Stoye JP, Kassiotis G. Antibody-induced internalisation of retroviral envelope glycoproteins is a signal initiation event. PLoS Pathog 2020; 16:e1008605. [PMID: 32453763 PMCID: PMC7274472 DOI: 10.1371/journal.ppat.1008605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/05/2020] [Accepted: 05/05/2020] [Indexed: 12/31/2022] Open
Abstract
As obligate parasites, viruses highjack, modify and repurpose the cellular machinery for their own replication. Viral proteins have, therefore, evolved biological functions, such as signalling potential, that alter host cell physiology in ways that are still incompletely understood. Retroviral envelope glycoproteins interact with several host proteins, extracellularly with their cellular receptor and anti-envelope antibodies, and intracellularly with proteins of the cytoskeleton or sorting, endocytosis and recirculation pathways. Here, we examined the impact of endogenous retroviral envelope glycoprotein expression and interaction with host proteins, particularly antibodies, on the cell, independently of retroviral infection. We found that in the commonly used C57BL/6 substrains of mice, where murine leukaemia virus (MLV) envelope glycoproteins are expressed by several endogenous MLV proviruses, the highest expressed MLV envelope glycoprotein is under the control of an immune-responsive cellular promoter, thus linking MLV envelope glycoprotein expression with immune activation. We further showed that antibody ligation induces extensive internalisation from the plasma membrane into endocytic compartments of MLV envelope glycoproteins, which are not normally subject to constitutive endocytosis. Importantly, antibody binding and internalisation of MLV envelope glycoproteins initiates signalling cascades in envelope-expressing murine lymphocytic cell lines, leading to cellular activation. Similar effects were observed by MLV envelope glycoprotein ligation by its cellular receptor mCAT-1, and by overexpression in human lymphocytic cells, where it required an intact tyrosine-based YXXΦ motif in the envelope glycoprotein cytoplasmic tail. Together, these results suggest that signalling potential is a general property of retroviral envelope glycoproteins and, therefore, a target for intervention. The outcome of viral infection depends on the balance between host immunity and the ability of the virus to avoid, evade or subvert it. The envelope glycoproteins of diverse viruses, including retroviruses, are displayed on the surface of virions and of infected cells and thus constitute the major target of the host antibody response. Antibody responses are elicited not only against infectious viruses we acquire during our life-history, but also against the numerous retroviral envelopes encoded by our genome and acquired during our species’ life-history. In turn, viruses have evolved ways to reduce exposure of their envelope glycoproteins to the host immune system, including constitutive endocytosis or antibody-induced internalisation. Using murine leukaemia viruses as models of infectious and endogenous retroviruses, we show that antibody binding to retroviral envelopes induces extensive internalisation of the envelope-antibody complex and initiates signalling cascades, ultimately leading to transcriptional activation of envelope glycoprotein-expressing lymphocytes. We further show that expression of endogenous retroviral envelopes is coupled to physiological lymphocyte activation, integrating them with the immune response. These findings reveal an unexpected layer of interaction between the host antibody response and retroviral envelope glycoproteins, which could be considered immune receptors.
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Affiliation(s)
- Veera Panova
- Retroviral Immunology, The Francis Crick Institute, United Kingdom
| | - Jan Attig
- Retroviral Immunology, The Francis Crick Institute, United Kingdom
| | - George R. Young
- Retrovirus-Host Interactions, The Francis Crick Institute, London, United Kingdom
| | - Jonathan P. Stoye
- Retrovirus-Host Interactions, The Francis Crick Institute, London, United Kingdom
- Department of Medicine, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - George Kassiotis
- Retroviral Immunology, The Francis Crick Institute, United Kingdom
- Department of Medicine, Faculty of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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11
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Dai YD, Dias P, Margosiak A, Marquardt K, Bashratyan R, Hu WY, Haskins K, Evans LH. Endogenous retrovirus Gag antigen and its gene variants are unique autoantigens expressed in the pancreatic islets of non-obese diabetic mice. Immunol Lett 2020; 223:62-70. [PMID: 32335144 DOI: 10.1016/j.imlet.2020.04.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/09/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
Endogenous retrovirus (ERV) are remnants of ancient retroviruses that have been incorporated into the genome and evidence suggests that they may play a role in the etiology of T1D. We previously identified a murine leukemia retrovirus-like ERV whose Env and Gag antigens are involved in autoimmune responses in non-obese diabetic (NOD) mice. In this study, we show that the Gag antigen is present in the islet stromal cells. Although Gag gene transcripts were present, Gag protein was not detected in diabetes-resistant mice. Cloning and sequencing analysis of individual Gag genes revealed that NOD islets express Gag gene variants with complete open-reading frames (ORFs), in contrast to the diabetes-resistant mice, whose islet Gag gene transcripts are mostly non-ORFs. Importantly, the ORFs obtained from the NOD islets are extremely heterogenous, coding for various mutants that are absence in the genome. We further show that Gag antigens are stimulatory for autoreactive T cells and identified one islet-expressing Gag variant that contains an altered peptide ligand capable of inducing IFN-gamma release by the T cells. The data highlight a unique retrovirus-like factor in the islets of the NOD mouse strain, which may participate in key events triggering autoimmunity and T1D.
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Affiliation(s)
- Yang D Dai
- Biomedical Research Institute of Southern California, Oceanside, CA, USA; Department of Immunology, Scripps Research, San Diego, CA, USA.
| | - Peter Dias
- Biomedical Research Institute of Southern California, Oceanside, CA, USA
| | - Amanda Margosiak
- Biomedical Research Institute of Southern California, Oceanside, CA, USA
| | | | | | | | - Kathryn Haskins
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Denver, CO, USA
| | - Leonard H Evans
- Laboratory of Persistent Viral Diseases, National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
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12
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Canli T. A model of human endogenous retrovirus (HERV) activation in mental health and illness. Med Hypotheses 2019; 133:109404. [PMID: 31557593 DOI: 10.1016/j.mehy.2019.109404] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/18/2019] [Indexed: 01/04/2023]
Abstract
Despite strong evidence for the heritability of major depressive disorder (MDD), efforts to identify causal genes have been disappointing. Furthermore, although there is strong support for life stress as a major predictor of MDD, there are also considerable individual differences in susceptibility and resilience that remain poorly understood. Efforts to identify specific gene-by-environment risk factors produced results that were initially encouraging, but that were not supported by later large-scale studies. Here I propose a novel mechanism that could address the "missing heritability" of MDD, the role of environmental risk factors, and individual differences in susceptibility and resilience. This mechanism focuses on a class of transposable elements, Human Endogenous Retroviruses (HERVs), which make up approximately 8% of the human genome as the result of ancient retroviral infections that entered mammalian germ lines throughout the course of evolution. My primary hypothesis is that exposure to either exogenous viruses or traumatic experiences can activate HERVs in the brain to cause depressive (and possibly other psychiatric) symptoms. My secondary hypothesis is that individual differences in vulnerability or resilience result from the balance of activated HERVs with pathogenic versus protective functions in the brain. Future research can test these hypotheses by analysis of postmortem human brain tissue from donors with known viral or trauma histories; animal studies manipulating HERV expression; cell culture studies examining regulatory mechanisms of HERV expression; and from brain imaging studies of individuals with known HERV-expression. Such research may reveal novel functions of HERVs in neural tissue and may lead to a new generation of psychiatric interventions designed to target aberrant HERV activation.
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MESH Headings
- Animals
- Brain/virology
- Cells, Cultured
- Cytokines/physiology
- Depressive Disorder, Major/etiology
- Depressive Disorder, Major/genetics
- Depressive Disorder, Major/immunology
- Depressive Disorder, Major/virology
- Disease Models, Animal
- Endogenous Retroviruses/genetics
- Endogenous Retroviruses/physiology
- Environmental Exposure
- Epigenesis, Genetic
- Gene Expression Regulation, Viral
- Gene-Environment Interaction
- Genes, Viral
- Humans
- Intercellular Signaling Peptides and Proteins/physiology
- Mice, Transgenic
- Models, Biological
- Models, Psychological
- Schizophrenia/pathology
- Schizophrenia/virology
- Stress, Psychological
- Terminal Repeat Sequences/genetics
- Virus Activation
- Virus Diseases/complications
- Virus Diseases/psychology
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Affiliation(s)
- Turhan Canli
- Departments of Psychology and Psychiatry, Stony Brook University, Stony Brook, NY 11794-2500, USA.
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13
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Greenig M. HERVs, immunity, and autoimmunity: understanding the connection. PeerJ 2019; 7:e6711. [PMID: 30984482 PMCID: PMC6452852 DOI: 10.7717/peerj.6711] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 02/28/2019] [Indexed: 12/30/2022] Open
Abstract
Since their discovery in the 1960s, further investigation into endogenous retroviruses (ERVs) has challenged the conventional view of viral sequences as exclusively parasitic elements. Once presumed to be a group of passive genetic relics, it is becoming increasingly clear that this view of ERVs, while generally accurate, is incorrect in many specific cases. Research has identified ERV genes that appear to be co-opted by their mammalian hosts, but the biological function of ERV elements in humans remains a controversial subject. One area that has attracted some attention in this domain is the role of co-opted ERV elements in mammalian immune systems. The relationship between ERVs and human autoimmune diseases has also been investigated, but has historically been treated as a separate topic. This review will summarize the current evidence concerning the phenotypic significance of ERVs, both in the healthy immune system and in manifestations of autoimmunity. Furthermore, it will evaluate the relationship between these fields of study, and propose previously-unexplored molecular mechanisms through which human endogenous retroviruses might contribute to certain autoimmune pathologies. Investigation into these novel mechanisms could further our understanding of the molecular basis of autoimmune disease, and may one day provide new targets for treatment.
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Affiliation(s)
- Matthew Greenig
- Department of Life Sciences, Imperial College London, London, United Kingdom
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14
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Barth M, Gröger V, Cynis H, Staege MS. Identification of human endogenous retrovirus transcripts in Hodgkin Lymphoma cells. Mol Biol Rep 2019; 46:1885-1893. [PMID: 30707417 DOI: 10.1007/s11033-019-04640-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 01/23/2019] [Indexed: 11/24/2022]
Abstract
During the last decades, the prognosis for patients with Hodgkin Lymphoma (HL) has been steadily improved. Nevertheless, new and less toxic therapy strategies have to be developed especially for patients with advanced disease. The activation of human endogenous retroviruses (HERV) is suspected to occur in HL and therefore, HERV might represent interesting target structures. In order to identify transcribed HERV of the HERV-H and HERV-K families in HL we used a reverse transcription-polymerase chain reaction based cloning approach. In addition to unspliced HERV-H and HERV-K transcripts, we detected spliced HERV-K transcripts that matched genomic sequences with the expected splicing-donor and splicing-acceptor sites. Of particular interest was the expression of HERV-K18 related transcripts at the CD48 locus. Our data indicate transcriptional activity of several HERV loci in HL cells.
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Affiliation(s)
- Marie Barth
- University Clinic and Outpatient Clinic for Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany
| | - Victoria Gröger
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120, Halle, Germany
| | - Holger Cynis
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, 06120, Halle, Germany
| | - Martin Sebastian Staege
- University Clinic and Outpatient Clinic for Pediatrics I, Martin Luther University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany.
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15
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Grandi N, Tramontano E. HERV Envelope Proteins: Physiological Role and Pathogenic Potential in Cancer and Autoimmunity. Front Microbiol 2018; 9:462. [PMID: 29593697 PMCID: PMC5861771 DOI: 10.3389/fmicb.2018.00462] [Citation(s) in RCA: 145] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/27/2018] [Indexed: 12/29/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are relics of ancient infections accounting for about the 8% of our genome. Despite their persistence in human DNA led to the accumulation of mutations, HERVs are still contributing to the human transcriptome, and a growing number of findings suggests that their expression products may have a role in various diseases. Among HERV products, the envelope proteins (Env) are currently highly investigated for their pathogenic properties, which could likely be participating to several disorders with complex etiology, particularly in the contexts of autoimmunity and cancer. In fact, HERV Env proteins have been shown, on the one side, to trigger both innate and adaptive immunity, prompting inflammatory, cytotoxic and apoptotic reactions; and, on the other side, to prevent the immune response activation, presenting immunosuppressive properties and acting as immune downregulators. In addition, HERV Env proteins have been shown to induce abnormal cell-cell fusion, possibly contributing to tumor development and metastasizing processes. Remarkably, even highly defective HERV env genes and alternative env splicing variants can provide further mechanisms of pathogenesis. A well-known example is the HERV-K(HML2) env gene that, depending on the presence or the absence of a 292-bp deletion, can originate two proteins of different length (Np9 and Rec) proposed to have oncogenic properties. The understanding of their involvement in complex pathological disorders made HERV Env proteins potential targets for therapeutic interventions. Of note, a monoclonal antibody directed against a HERV-W Env is currently under clinical trial as therapeutic approach for multiple sclerosis, representing the first HERV-based treatment. The present review will focus on the current knowledge of the HERV Env expression, summarizing its role in human physiology and its possible pathogenic effects in various cancer and autoimmune disorders. It moreover analyzes HERV Env possible exploitation for the development of innovative therapeutic strategies.
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Affiliation(s)
- Nicole Grandi
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
| | - Enzo Tramontano
- Laboratory of Molecular Virology, Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy
- Istituto di Ricerca Genetica e Biomedica, Consiglio Nazionale delle Ricerche, Cagliari, Italy
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16
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Gröger V, Cynis H. Human Endogenous Retroviruses and Their Putative Role in the Development of Autoimmune Disorders Such as Multiple Sclerosis. Front Microbiol 2018; 9:265. [PMID: 29515547 PMCID: PMC5826199 DOI: 10.3389/fmicb.2018.00265] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 02/05/2018] [Indexed: 12/13/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are remnants of retroviral germ line infections of human ancestors and make up ~8% of the human genome. Under physiological conditions, these elements are frequently inactive or non-functional due to deactivating mutations and epigenetic control. However, they can be reactivated under certain pathological conditions and produce viral transcripts and proteins. Several disorders, like multiple sclerosis or amyotrophic lateral sclerosis are associated with increased HERV expression. Although their detailed contribution to individual diseases has yet to be elucidated, an increasing number of studies in vitro and in vivo suggest HERVs as potent modulators of the immune system. They are able to affect the transcription of other immune-related genes, interact with pattern recognition receptors, and influence the positive and negative selection of developing thymocytes. Interestingly, HERV envelope proteins can both stimulate and suppress immune responses based on different mechanisms. In the light of HERV proteins becoming an emerging drug target for autoimmune-related disorders and cancer, we will provide an overview on recent findings of the complex interactions between HERVs and the human immune system with a focus on autoimmunity.
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Affiliation(s)
| | - Holger Cynis
- Department of Drug Design and Target Validation, Fraunhofer Institute for Cell Therapy and Immunology, Halle, Germany
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17
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de Mulder M, SenGupta D, Deeks SG, Martin JN, Pilcher CD, Hecht FM, Sacha JB, Nixon DF, Michaud HA. Anti-HERV-K (HML-2) capsid antibody responses in HIV elite controllers. Retrovirology 2017; 14:41. [PMID: 28830571 PMCID: PMC5568399 DOI: 10.1186/s12977-017-0365-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/13/2017] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Human endogenous retroviruses (HERVs) comprise approximately 8% of the human genome and while the majority are transcriptionally silent, the most recently integrated HERV, HERV-K (HML-2), remains active. During HIV infection, HERV-K (HML-2) specific mRNA transcripts and viral proteins can be detected. In this study, we aimed to understand the antibody response against HERV-K (HML-2) Gag in the context of HIV-1 infection. RESULTS We developed an ELISA assay using either recombinant protein or 164 redundant "15mer" HERV-K (HML-2) Gag peptides to test sera for antibody reactivity. We identified a total of eight potential HERV-K (HML-2) Gag immunogenic domains: two on the matrix (peptides 16 and 31), one on p15 (peptide 85), three on the capsid (peptides 81, 97 and 117), one on the nucleocapsid (peptide 137) and one on the QP1 protein (peptide 157). Four epitopes (peptides 16, 31, 85 and 137) were highly immunogenic. No significant differences in antibody responses were found between HIV infected participants (n = 40) and uninfected donors (n = 40) for 6 out of the 8 epitopes tested. The antibody response against nucleocapsid (peptide 137) was significantly lower (p < 0.001), and the response to QP1 (peptide 157) significantly higher (p < 0.05) in HIV-infected adults compared to uninfected individuals. Among those with HIV infection, the level of response against p15 protein (peptide 85) was significantly lower in untreated individuals controlling HIV ("elite" controllers) compared to untreated non-controllers (p < 0.05) and uninfected donors (p < 0.05). In contrast, the response against the capsid protein (epitopes 81 and 117) was significantly higher in controllers compared to uninfected donors (p < 0.001 and <0.05 respectively) and non-controllers (p < 0.01 and <0.05). Peripheral blood mononuclear cells (PBMCs) from study participants were tested for responses against HERV-K (HML-2) capsid recombinant peptide in gamma interferon (IFN-γ) enzyme immunospot (Elispot) assays. We found that the HERV-K (HML-2) Gag antibody and T cell response by Elispot were significantly correlated. CONCLUSIONS HIV elite controllers had a strong cellular and antibody response against HERV-K (HML-2) Gag directed mainly against the Capsid region. Collectively, these data suggest that anti-HERV-K (HML-2) antibodies targeting capsid could have an immunoprotective effect in HIV infection.
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Affiliation(s)
- Miguel de Mulder
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Ross Hall 604, 2300 Eye St. NW, Washington, DC 20037 USA
| | - Devi SenGupta
- Gilead Sciences Inc., Foster City, CA USA
- Division of Experimental Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Steven G. Deeks
- HIV/AIDS Program, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Jeffrey N. Martin
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA USA
| | - Christopher D. Pilcher
- HIV/AIDS Program, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Frederick M. Hecht
- HIV/AIDS Program, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Jonah B. Sacha
- Division of Pathobiology and Immunology, Oregon Health and Science University, Portland, CA USA
| | - Douglas F. Nixon
- Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Ross Hall 604, 2300 Eye St. NW, Washington, DC 20037 USA
- Division of Experimental Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
| | - Henri-Alexandre Michaud
- Division of Experimental Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA USA
- Equipe Immunité et Cancer, Institut de Recherche en Cancérlogie de Montpellier, Montpellier, France
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18
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Kim HJ, Moon BI, Lee JW, Kim SC, Kim HJ. Age-related reduction of antibody response against the human endogenous retrovirus K envelope in women. Oncotarget 2017; 7:17327-37. [PMID: 26872058 PMCID: PMC4951215 DOI: 10.18632/oncotarget.7307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/29/2016] [Indexed: 01/14/2023] Open
Abstract
In the present study, the correlation between the antibody response against human endogenous retrovirus K (HERV-K) envelope and human age was investigated. Antibody levels were compared in groups in their 20s (n = 25), 30s (n = 39), 40s (n = 68), 50s (n = 32), and 60s and over (n = 25), which included healthy individuals and breast cancer and/or cervical cancer patients. It appeared that both IgM and IgG responses against the HERV-K envelope fell with increasing age. There were no differences in anti-HERV-K envelope antibody levels between healthy individuals and cancer patients. Therefore, our results indicated that the anti-HERV-K antibody levels cannot be considered as cancer-specific marker. Also, IgG1 appeared to be the predominant subtype in the reduction of the IgG response by age. Receiver operating characteristic curves of anti-HERV-K envelope IgM levels indicated that the groups of people in their 20s or 30s could be distinguished from those in their 40s, 50s or 60s and over with satisfactory sensitivity and specificity. These findings indicate that the serum antibody level of HERV-K envelope is a critical parameter reflecting person's age.
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Affiliation(s)
- Hyoung Jin Kim
- Laboratory of Virology, College of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul 06974, South Korea
| | - Byung-In Moon
- Breast and Thyroid Cancer Center, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Jun Woo Lee
- Breast and Thyroid Cancer Center, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Seung Cheol Kim
- Department of Obstetrics and Gynecology, Ewha Womans University College of Medicine, Yangcheon-Gu, Seoul 07985, South Korea
| | - Hong-Jin Kim
- Laboratory of Virology, College of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul 06974, South Korea
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19
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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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20
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Perzova R, Graziano E, Sanghi S, Welch C, Benz P, Abbott L, Lalone D, Glaser J, Loughran T, Sheremata W, Poiesz BJ. Increased seroreactivity to human T cell lymphoma/leukemia virus-related endogenous sequence-1 Gag peptides in patients with human T cell lymphoma/leukemia virus myelopathy. AIDS Res Hum Retroviruses 2015; 31:242-9. [PMID: 25295378 DOI: 10.1089/aid.2014.0171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previously, we had shown that although only 8% of patients with large granular lymphocytic leukemia (LGLL) were infected with human T cell lymphoma/leukemia virus (HTLV)-2, almost half had antibodies to HTLV Gag and Env peptides. Herein, we investigated whether this could be due to cross-reactive antibodies to two homologous peptides in the Gag protein of the endogenous retrovirus HTLV-related endogenous sequence-1 (HRES-1). In addition, we had previously shown that patients with HTLV neurodegenerative diseases had increased seroreactivity to homologous HERV-K10 endogenous retrovirus peptides. Hence, in this study we also examined whether these patients had increased seroreactivity to the aforementioned HRES-1 Gag peptides. Sera from 100 volunteer blood donors (VBD), 53 patients with LGLL, 74 subjects with HTLV-1 or 2 infection (58 nonmyelopathy and 16 myelopathy), and 83 patients with multiple sclerosis (MS) were evaluated. The HTLV-positive myelopathy (HAM) patients had a statistically increased prevalence of antibodies to both HRES-1 Gag peptides (81%) vs. the VBD (0%), LGLL patients (13%), and MS patients (1%), and the HTLV-positive nonmyelopathy subjects (21%). The data suggest that cross-reactivity to HRES-1 peptides could be involved in the pathogenesis of HAM. The difference between the VBD and LGLL patients was also statistically significant, also suggesting a possible association in a minority of patients.
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Affiliation(s)
- Raisa Perzova
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Elliot Graziano
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Swathi Sanghi
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Caitlin Welch
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Patricia Benz
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Lynn Abbott
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Danielle Lalone
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
| | - Jordan Glaser
- Division of Infectious Diseases, Department of Medicine, Staten Island Hospital, New York, New York
| | - Thomas Loughran
- Emily Couric Clinical Cancer Center, Charlottesville, Virginia
| | | | - Bernard J. Poiesz
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, New York
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21
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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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22
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Nelson PN, Roden D, Nevill A, Freimanis GL, Trela M, Ejtehadi HD, Bowman S, Axford J, Veitch AM, Tugnet N, Rylance PB. Rheumatoid Arthritis is Associated with IgG Antibodies to Human Endogenous Retrovirus Gag Matrix: A Potential Pathogenic Mechanism of Disease? J Rheumatol 2014; 41:1952-60. [DOI: 10.3899/jrheum.130502] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Objective.Human endogenous retrovirus (HERV)-K10 has been implicated in the etiology and pathogenesis of rheumatoid arthritis (RA). A secondary immune response to this virus might suggest an antigen-driven response in patients. The Gag region of HERV-K10 could provide a key epitope important for immunological reactivity. We investigated the presence of IgG antibodies to this region and assessed its significance in RA.Methods.We determined an antigenic peptide on the matrix segment of HERV-K10 and developed an ELISA system to detect IgG antibodies in patients with RA and controls. The presence of antibodies to the matrix peptide (denoted as MAG1: RIGKELKQAGRKGNI) was correlated with patient details.Results.On screening patients’ serum, we found a significantly higher mean IgG antibody response to MAG1 in 30 patients with RA as compared to 23 patients with inflammatory bowel disease (p = 0.003), 29 patients with osteoarthritis (p = 0.001), and 43 healthy individuals (p = 0.002). Reactivity was not observed to a control peptide possessing a nonhomologous amino acid sequence. On evaluating clinical details with serological activity, no correlation with disease duration (p = 0.128), sex (p = 0.768), or rheumatoid factor status (p = 0.576) was found.Conclusion.A significantly elevated IgG antibody response to an HERV-K10 Gag matrix peptide was observed in patients with RA, suggesting that the exposure of HERV-K10 may cause a secondary, antigenic driven immune response in RA.
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Downey RF, Sullivan FJ, Wang-Johanning F, Ambs S, Giles FJ, Glynn SA. Human endogenous retrovirus K and cancer: Innocent bystander or tumorigenic accomplice? Int J Cancer 2014; 137:1249-57. [PMID: 24890612 PMCID: PMC6264888 DOI: 10.1002/ijc.29003] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 05/02/2014] [Accepted: 05/09/2014] [Indexed: 12/20/2022]
Abstract
Harbored as relics of ancient germline infections, human endogenous retroviruses (HERVs) now constitute up to 8% of our genome. A proportion of this sequence has been co-opted for molecular and cellular processes, beneficial to human physiology, such as the fusogenic activity of the envelope protein, a vital component of placentogenesis. However, the discovery of high levels of HERV-K mRNA and protein and even virions in a wide array of cancers has revealed that HERV-K may be playing a more sinister role–a role as an etiological agent in cancer itself. Whether the presence of this retroviral material is simply an epiphenomenon, or an actual causative factor, is a hotly debated topic. This review will summarize the current state of knowledge regarding HERV-K and cancer and attempt to outline the potential mechanisms by which HERV-K could be involved in the onset and promotion of carcinogenesis.
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Affiliation(s)
- Ronan F Downey
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland
| | - Francis J Sullivan
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland.,Department of Radiation Oncology, Galway University Hospitals, Galway, Ireland
| | | | - Stefan Ambs
- Laboratory of Human Carcinogenesis, National Cancer Institute, Bethesda, MD
| | - Francis J Giles
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland.,HRB Clinical Research Facilities Galway & Dublin, National University of Ireland Galway and Trinity College Dublin, Galway, Ireland
| | - Sharon A Glynn
- Prostate Cancer Institute, National University of Ireland Galway, Galway, Ireland
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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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Perzova R, Graziano E, Sanghi S, Welch C, Benz P, Abbott L, Lalone D, Glaser J, Loughran T, Sheremata W, Poiesz BJ. Increased seroreactivity to HERV-K10 peptides in patients with HTLV myelopathy. Virol J 2013; 10:360. [PMID: 24365054 PMCID: PMC3878045 DOI: 10.1186/1743-422x-10-360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/16/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Previously, we had shown that persons infected with human T-cell lymphoma leukemia virus 1 or 2 (HTLV-1 or 2) had an increased prevalence of antibodies to a peptide in the Pol protein of the retrovirus HERV-K10, homologous to a peptide in HTLV gp21 envelope protein. The prevalence rate was higher in those with myelopathy vs. non-myelopathy. We have now extended our observations to a cohort restricted to North America in whom the diagnosis of HTLV myelopathy was rigorously confirmed to also test for reactivity to another HERV-K10 peptide homologous to the HTLV p24 Gag protein. METHODS Sera from 100 volunteer blood donors (VBD), 53 patients with large granular lymphocytic leukemia (LGLL), 74 subjects with HTLV-1 or 2 infection (58 non-myelopathy and 16 myelopathy) and 83 patients with multiple sclerosis (MS) were evaluated in ELISA assays using the above peptides. RESULTS The HTLV myelopathy patients had a statistically significant increased prevalence of antibodies to both HERV-K10 peptides (87.5%) vs. the VBD (0%), LGLL patients (0%), MS patients (4.8%), and the HTLV positive non-myelopathy subjects (5.2%). CONCLUSION The data suggest that immuno-cross-reactivity to HERV-K10 peptides and/or transactivation of HERV-K10 expression by the HTLV Tax protein may be involved in the pathogenesis of HTLV-associated myelopathy/tropical spastic paraparesis and spastic ataxia.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Bernard J Poiesz
- Department of Medicine, Division of Hematology/Oncology, State University of New York, Upstate Medical University, Syracuse, NY 13210, USA.
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Magiorkinis G, Belshaw R, Katzourakis A. 'There and back again': revisiting the pathophysiological roles of human endogenous retroviruses in the post-genomic era. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120504. [PMID: 23938753 PMCID: PMC3758188 DOI: 10.1098/rstb.2012.0504] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Almost 8% of the human genome comprises endogenous retroviruses (ERVs). While they have been shown to cause specific pathologies in animals, such as cancer, their association with disease in humans remains controversial. The limited evidence is partly due to the physical and bioethical restrictions surrounding the study of transposons in humans, coupled with the major experimental and bioinformatics challenges surrounding the association of ERVs with disease in general. Two biotechnological landmarks of the past decade provide us with unprecedented research artillery: (i) the ultra-fine sequencing of the human genome and (ii) the emergence of high-throughput sequencing technologies. Here, we critically assemble research about potential pathologies of ERVs in humans. We argue that the time is right to revisit the long-standing questions of human ERV pathogenesis within a robust and carefully structured framework that makes full use of genomic sequence data. We also pose two thought-provoking research questions on potential pathophysiological roles of ERVs with respect to immune escape and regulation.
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Tugnet N, Rylance P, Roden D, Trela M, Nelson P. Human Endogenous Retroviruses (HERVs) and Autoimmune Rheumatic Disease: Is There a Link? Open Rheumatol J 2013; 7:13-21. [PMID: 23750183 PMCID: PMC3636489 DOI: 10.2174/1874312901307010013] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/14/2013] [Accepted: 01/16/2013] [Indexed: 12/25/2022] Open
Abstract
Autoimmune rheumatic diseases, such as RA and SLE, are caused by genetic, hormonal and environmental factors. Human Endogenous Retroviruses (HERVs) may be triggers of autoimmune rheumatic disease. HERVs are fossil viruses that began to be integrated into the human genome some 30-40 million years ago and now make up 8% of the genome. Evidence suggests HERVs may cause RA and SLE, among other rheumatic diseases. The key mechanisms by which HERVS are postulated to cause disease include molecular mimicry and immune dysregulation. Identification of HERVs in RA and SLE could lead to novel treatments for these chronic conditions. This review summarises the evidence for HERVs as contributors to autoimmune rheumatic disease and the clinical implications and mechanisms of pathogenesis are discussed.
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Affiliation(s)
- Nicola Tugnet
- Department of Rheumatology, Royal Wolverhampton Hospitals NHS Trust, Wolverhampton, UK
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Expression of human endogenous retrovirus type K (HML-2) is activated by the Tat protein of HIV-1. J Virol 2012; 86:7790-805. [PMID: 22593154 DOI: 10.1128/jvi.07215-11] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human endogenous retroviruses (HERVs) make up 8% of the human genome. The expression of HERV-K (HML-2), the family of HERVs that most recently entered the genome, is tightly regulated but becomes markedly increased after infection with HIV-1. To better understand the mechanisms involved in this activation, we explored the role of the HIV-1 Tat protein in inducing the expression of these endogenous retroviral genes. Administration of recombinant HIV-1 Tat protein caused a 13-fold increase in HERV-K (HML-2) gag RNA transcripts in Jurkat T cells and a 10-fold increase in primary lymphocytes, and the expression of the HERV-K (HML-2) rec and np9 oncogenes was also markedly increased. This activation was seen especially in lymphocytes and monocytic cells, the natural hosts for HIV-1 infection. Luciferase reporter gene assays demonstrated that the effect of Tat on HERV-K (HML-2) expression occurred at the level of the transcriptional promoter. The transcription factors NF-κB and NF-AT contribute to the Tat-induced activation of the promoter, as shown by chromatin immunoprecipitation assays, mutational analysis of the HERV-K (HML-2) long terminal repeat, and treatments with agents that inhibit NF-κB or NF-AT activation. These studies demonstrate that HIV-1 Tat plays an important role in activating expression of HERV-K (HML-2) in the setting of HIV-1 infection.
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Balada E, Vilardell-Tarrés M, Ordi-Ros J. Implication of Human Endogenous Retroviruses in the Development of Autoimmune Diseases. Int Rev Immunol 2010; 29:351-70. [DOI: 10.3109/08830185.2010.485333] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Buzdin AA. [Functional analysis of retroviral endogenous inserts in the human genome evolution]. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2010; 36:38-46. [PMID: 20386577 DOI: 10.1134/s1068162010010048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Retroelements, mobile elements produced in DNA by reverse transcription, comprise about 40% of the human genome. A small part of these elements appeared in the genome quite recently after the divergence of humans and chimpanzees had occurred. Evolutionarily young retroelements are represented by the members of four groups, SVA, Alu, L1, and the endogenous HERV-K (HML-2) virus. These retroelements could play a functional role in the course of the molecular evolution of human DNA. We comprehensively studied the contribution of human-specific endogenous viruses (hsERV) to the structural modifications and regulation of the human genome. We found that hsERV presented in 134 copies occupied about 330 000 bp of human DNA. They added to genomic sequences the copies of 50 functional retroviral genes as well as 134 potential promoters and enhancers, 50% of which are located in the regions adjacent to known genes, and 22% in gene introns. At least 67% of these elements are human-specific promoters in vivo. hsERV viruses regulate the activity of known protein-encoding genes by means of RNA interference, function as enhancers, and provide new polyadenylation signals for mRNA.
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Thomas A, Perzova R, Abbott L, Benz P, Poiesz MJ, Dube S, Loughran T, Ferrer J, Sheremata W, Glaser J, Leon-Ponte M, Poiesz BJ. LGL leukemia and HTLV. AIDS Res Hum Retroviruses 2010; 26:33-40. [PMID: 20047475 DOI: 10.1089/aid.2009.0124] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Samples were obtained from 53 large granular lymphocytic leukemia (LGLL) patients and 10,000 volunteer blood donors (VBD). Sera were screened in an HTLV-1 enzyme immunoassay (EIA) and further analyzed in peptide-specific Western blots (WB). DNAs were analyzed by HTLV-1, -2, -3, and -4-specific PCR. Forty four percent of LGLL patients vs. 0.12 % of VBD had anti-HTLV antibodies via EIA (p < 0.001). WB and PCR revealed that four LGLL patients (7.5%) vs. one VBD patient (0.01%) were infected with HTLV-2 (p < 0.001), suggesting an HTLV-2 etiology in a minority of cases. No LGLL patient was positive for HTLV-1, -3, or -4, whereas only one EIA-positive VBD was positive for HTLV-1 and none for HTLV-3 or -4. The HTLV EIA-positive, PCR-negative LGLL patients' sera reacted to epitopes within HTLV p24 gag and gp21 env. Other then the PTLV/BLV viruses, human endogenous retroviral element HERV K10 was the only sequence homologous to these two HTLV peptides, raising the possibility of cross-reactivity. Although three LGLL patients (5.7%) vs. none of 110 VBD patients tested positive for antibodies to the homologous HERV K10 peptide (p = 0.03), the significance of the anti-HTLV seroreactivity observed in many LGLL patients remains unclear. Interestingly, out of 36 HTLV-1-positive control subjects, 3 (8%) (p = 0.014) were positive for antibodies to HERV K10; all three had myelopathy. Out of 64 HTLV-2-positive control subjects 16 (25%) (p = <0.001) were positive for HERV K10 antibodies, and 4 (6%) of these had myelopathy. Out of 22 subjects with either HTLV-1 or -2 myelopathy, 7 (31.8%) were positive for HERV K10 antibodies, and out of 72 HTLV-infected subjects without myelopathy, 12 (16.7%) were positive for anti-HERV K10 antibodies (p = 0.11). The prevalence of anti-HERV K10 antibodies in these populations and the clinical implications thereof need to be pursued further.
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Affiliation(s)
- Anish Thomas
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
| | - Raisa Perzova
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
| | - Lynn Abbott
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
| | - Patricia Benz
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
| | - Michael J. Poiesz
- Department of Medicine, New York University Medical Center, New York, New York 13210
| | - Syamalima Dube
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
| | - Thomas Loughran
- Penn State Cancer Institute, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania 17103
| | - Jorge Ferrer
- Comparative Leukemia and Retroviruses Unit, New Bolton Center University of Pennsylvania, Kennett Square, Pennsylvania 19348
| | | | - Jordan Glaser
- Division of Infectious Disease, Department of Medicine, Staten Island Hospital, New York, New York 10305
| | - Matilde Leon-Ponte
- Robarts Research Institute, University of Western Ontario, London, Ontario, Canada
| | - Bernard J. Poiesz
- Division of Hematology/Oncology, Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13202
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Blank M, Shoenfeld Y, Perl A. Cross-talk of the environment with the host genome and the immune system through endogenous retroviruses in systemic lupus erythematosus. Lupus 2009; 18:1136-43. [DOI: 10.1177/0961203309345728] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Environmental factors are capable of triggering the expression of human endogenous retroviruses and induce an autoimmune response. Infection can promote the expression of human endogenous retroviruses by molecular mimicry or by functional mimicry. There are additional mechanisms which may control the expression of human endogenous retroviruses, such as epigenetic status of the genome (hypomethylation, histone deacetylation). Ultraviolet exposure, chemicals/drugs, injury/stress, hormones, all as a single cause or in a concert, may modulate the involvement of human endogenous retroviruses in pathogenic processes. In the current review we summarize the current knowledge on infections, molecular mimicry, cross-reactivity and epigenetics contribution for trigger human endogenous retroviruses expression and pathogenesis in lupus patients. Lupus (2009) 18, 1136—1143.
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Affiliation(s)
- M. Blank
- Center for Autoimmune Diseases, an Department of Medicine 'B', Sheba Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Hashomer, Israel,
| | - Y. Shoenfeld
- Center for Autoimmune Diseases, an Department of Medicine 'B', Sheba Medical Center, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Hashomer, Israel, Incumbent of the Laura Schwarz-Kip Chair for Research of Autoimmune Diseases, Tel-Aviv University, Israel
| | - A. Perl
- Division of Rheumatology, Department of Medicine, State University of New York Upstate Medical University, Syracuse, NY, USA
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Reynier F, Verjat T, Turrel F, Imbert PE, Marotte H, Mougin B, Miossec P. Increase in human endogenous retrovirus HERV-K (HML-2) viral load in active rheumatoid arthritis. Scand J Immunol 2009; 70:295-9. [PMID: 19703019 DOI: 10.1111/j.1365-3083.2009.02271.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: 11/30/2022]
Abstract
To study the viral loads of human endogenous retrovirus HERV-K (HML-2) type 1 and type 2 in rheumatoid arthritis (RA), we measured the viral loads of HERV-K (HML-2) type 1 and type 2 using nucleic acid sequence-based amplification (NASBA) technology. We analyzed plasma samples from RA patients (n = 79) and healthy volunteers (HV, n = 46) and synovial fluid samples from RA (n = 10) and osteoarthritis (OA, n = 10) patients. HERV-K type 1 and type 2 viruses were detected and quantified for the majority of plasma and synovial fluid samples from RA patients. HERV-K type 1 and type 2 viral loads were significantly elevated in RA patients compared with HV in plasma (P < 0.0001) and from RA patients compared with OA patients in synovial fluid (type 1: P = 0.0007; type 2: P = 0.023). Moreover, an association was observed between the HERV-K type 1 viral load in plasma and the disease activity in RA patients (RA patients with low activity versus high activity P = 0.0129; RA patients with intermediate activity versus high activity P = 0.037). Our findings showed that HERV-K (HML-2) viral load can be detected in plasma samples from RA patients, with higher levels observed for those with active disease. There was an association of HERV-K type 1 levels with the disease activity.
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Affiliation(s)
- F Reynier
- Joint Unit Hospices Civils de Lyon - bioMérieux, and Department of Immunology and Rheumatology, Immunogenomics and inflammation research Unit EA 4130, University of Lyon, Lyon, France
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Abstract
The capacity to integrate into the chromosomal DNA of germ-line cells has endowed retroviruses with the potential to be vertically transmitted from generation to generation and eventually become fixed in the genomes of the entire population. This has been independently accomplished by several ancient retroviruses that invaded the genomes of our early and more recent primate and hominoid ancestors. Some of the inherited elements then proliferated in the genome, resulting in a number of lineages with complex phylogenetic patterns. Although the vast majority of chromosomally integrated retroelements have suffered inactivating mutations and deletions, a significant impact on various aspects of human biology has been recently revealed and evidence for the present activity of at least one human endogenous retrovirus family continues to accumulate.
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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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Guilhou JJ, Molès JP. New Hypotheses in the Genetics of Psoriasis and Other ‘Complex’ Diseases. Dermatology 2008; 216:87-92. [DOI: 10.1159/000111504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Accepted: 07/18/2007] [Indexed: 12/30/2022] Open
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Abstract
Endogenous retroviruses (ERVs) integrated into human genome after cross-species infectious events millions of years ago. Few of the ERVs retain the basic structure of the integrated proviral form of infectious retroviruses. Human endogenous retroviruses (HERVs) represent a key molecular link between the host genome and infectious viral particles. They constitute a large reservoir of viral genes that could be activated by various factors such as mutations or carcinogenic chemical exposures and so forth. Endogenous retroviruses are transmitted genetically in a Mendelian fashion through the germline as proviral DNA. Expression pattern of HERVs can influence the outcome of their presence in many forms, which can be either beneficial or detrimental to the host. ERVs have been reported to play a role in both human physiology and human pathology. Along with their expression in many disease conditions, they have also been reported to be expressed on normal peripheral blood lymphocytes, salivary glands and keratinocytes.
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Affiliation(s)
- Sunit Kumar Singh
- Center for Cellular and Molecular Biology, Section of Infectious Diseases, Hyderabad, India.
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Moyes D, Griffiths DJ, Venables PJ. Insertional polymorphisms: a new lease of life for endogenous retroviruses in human disease. Trends Genet 2007; 23:326-33. [PMID: 17524519 DOI: 10.1016/j.tig.2007.05.004] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 04/16/2007] [Accepted: 05/11/2007] [Indexed: 10/23/2022]
Abstract
Human endogenous retroviruses (HERVs) result from ancestral infection by infectious viruses over millions of years of primate evolution. Some are transcriptionally active, express proteins and therefore have the potential to cause disease. Here we review the controversial attempts to link them with cancer and autoimmunity. The main difficulty is that most HERVs investigated to date are present at the same locus in 100% of the population. However, a new class of insertionally polymorphic HERV-K family members, present in a minority of individuals, has recently been described. We propose that insertionally polymorphic HERVs could be novel genetic risk factors and hence provide a new lease of life for research into HERVs and disease.
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Affiliation(s)
- David Moyes
- The Kennedy Institute of Rheumatology, Imperial College London, London, UK
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Abstract
Molecular epidemiologic proof that HERVs and other retroelements are involved in autoimmunity or other disorders is complicated by their large numbers in the human genome. As discussed, most HERVs are no longer functional or active because of the accumulation of mutations, frameshifts, and deletions. Detection or quantification of HERV transcripts that may be pathologically involved in a particular autoimmune disease thus is often compromised by the presence in great excess of related, but nonfunctional, RNA. This phenomenon should not deter active work in the field, although it will require development of improved methods to discriminate accurately between closely related RNA transcripts. Development of improved immunologic methods to precisely identify epitopes on autoantigens or rare self-reactive T-cell clones may further implicate HERVs and the other repetitive elements in regulation of the immune system in health and disease.
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Affiliation(s)
- Ines Colmegna
- Section of Rheumatology, Department of Medicine, Louisiana State University Health Sciences Center, 2020 Gravier Street, New Orleans, LA 70112, USA
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Schulz WA, Steinhoff C, Florl AR. Methylation of endogenous human retroelements in health and disease. Curr Top Microbiol Immunol 2006; 310:211-50. [PMID: 16909913 DOI: 10.1007/3-540-31181-5_11] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Retroelements constitute approximately 45% of the human genome. Long interspersed nuclear element (LINE) autonomous retrotransposons are predominantly represented by LINE-1, nonautonomous small interspersed nuclear elements (SINEs) are primarily represented by ALUs, and LTR retrotransposons by several families of human endogenous retroviruses (HERVs). The vast majority of LINE and HERV elements are densely methylated in normal somatic cells and contained in inactive chromatin. Methylation and chromatin structure together ensure a stable equilibrium between retroelements and their host. Hypomethylation and expression in developing germ cells opens a "window of opportunity" for retrotransposition and recombination that contribute to human evolution, but also inherited disease. In somatic cells, the presence of retroelements may be exploited to organize the genome into active and inactive regions, to separate domains and functional regions within one chromatin domain, to suppress transcriptional noise, and to regulate transcript stability. Retroelements, particularly ALUs, may also fulfill physiological roles during responses to stress and infections. Reactivation and hypomethylation of LINEs and HERVs may be important in the pathophysiology of cancer and various autoimmune diseases, contributing to chromosomal instability and chronically aberrant immune responses. The emerging insights into the pathophysiological importance of endogenous retroelements accentuate the gaps in our knowledge of how these elements are controlled in normal developing and mature cells.
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Affiliation(s)
- W A Schulz
- Urologische Klinik, Heinrich Heine Universität, Düsseldorf, Germany.
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Humer J, Waltenberger A, Grassauer A, Kurz M, Valencak J, Rapberger R, Hahn S, Löwer R, Wolff K, Bergmann M, Muster T, Mayer B, Pehamberger H. Identification of a Melanoma Marker Derived from Melanoma-Associated Endogenous Retroviruses. Cancer Res 2006; 66:1658-63. [PMID: 16452225 DOI: 10.1158/0008-5472.can-05-2452] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We previously described the expression of melanoma-associated endogenous retrovirus (MERV) proteins and viral particles in human melanomas and metastases. The objective of the present study was to determine whether a humoral immune response to MERV proteins occurs in melanoma. Candidate B-cell epitopes on MERV proteins were predicted using bioinformatic screening. The reactivity of MERV peptides corresponding to the predicted epitopes with antibodies prevalent in sera of melanoma patients was analyzed. An immunodominant peptide located in the env protein of MERV was identified. Subsequent analyzes using 81 samples from stage I to stage IV melanoma patients and 95 sera from healthy subjects revealed statistically significant differences in seroprevalence of antibodies in melanoma sera samples when compared with reference samples from healthy subjects. The prevalence of anti-MERV antibodies in melanoma patient sera was confirmed by immunofluorescence on env-transfected cells. These data indicate the potential of this candidate peptide as target for diagnosis and immunotherapy.
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Affiliation(s)
- Johannes Humer
- Department of Dermatology, Division of General Dermatology, Green Hills Biotechnology GmbH, Gersthoferstrasse 29-31, 1180 Vienna, Austria
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Nelson PN, Astley SJ, Roden D, Waldron E, Baig K, Caforio ALP, Koutedakis Y, Perera S, Spry C. Characterization of Anti-Myosin Monoclonal Antibodies. Hybridoma (Larchmt) 2005; 24:314-8. [PMID: 16332199 DOI: 10.1089/hyb.2005.24.314] [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: 11/13/2022]
Abstract
The characterization of monoclonal antibodies (MAbs) with regard to reactivity and specificity is important for the successful application as a molecular probe and/or diagnostic reagent. Furthermore, it is recognized that some monoclonal reagents perform well in some assay systems but not others. In this study, the reactivity profiles of two anti-myosin MAbs (H1 and DH2, raised against human cardiac myosin) were evaluated in enzyme-linked immunosorbent assay (ELISA), slot-blotting, and immunocytochemistry. Both antibodies performed well in slot-blotting against myosin heavy chain preparations from cardiac and skeletal muscle and from non-human sources. In general, MAb H1 demonstrated strong to moderate reactivity in all assay systems, whilst MAb DH2 faired poorly in ELISA. MAb H1 also showed reactivity to synthetic peptides of myosin, one of which possessed a motif (ERRDA, single amino acid code) that was found in other human and nonhuman myosin protein sequences that could explain its cross-reactive profile. Intriguingly, this motif was found on viral and other pathogenic agents associated with myocarditis. Hence, it is speculated that this region could give some credence to the mechanism of molecular mimicry associated with some cardiac diseases. Overall, MAb H1 may serve as a useful probe of myosin structure.
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Affiliation(s)
- P N Nelson
- Molecular Immunology Research Group, Research Institute in Healthcare Science, School of Applied Sciences, University of Wolverhampton, Wolverhampton, United Kingdom.
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Taruscio D, Mantovani A. Factors regulating endogenous retroviral sequences in human and mouse. Cytogenet Genome Res 2005; 105:351-62. [PMID: 15237223 DOI: 10.1159/000078208] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2003] [Accepted: 12/23/2003] [Indexed: 11/19/2022] Open
Abstract
Endogenous retroviruses (ERVs) are stably integrated in the genome of vertebrates and inherited as Mendelian genes. The several human ERV (HERV) families and related elements represent up to 5-8% of the DNA of our species. ERVs may be involved in the regulation of adjacent genomic loci, especially promoting the tissue-specific expression of genes; some HERVs may have functional roles, e.g., coding for the placental fusogenic protein, syncytin. This paper reviews the growing evidence about factors that may modulate ERVs, including: cell and tissue types (with special attention to placenta and germ cells), processes related to differentiation and aging, cytokines, agents that disrupt cell functions (e.g., DNA hypomethylating agents) and steroids. Special attention is given to HERVs, due to their possible involvement in autoimmunity and reproduction, as well as altered expression in some cancer types; moreover, different HERV families may deserve specific attention, due to remarkable differences concerning, e.g., expression in tissues. A comparison with factors interacting with murine ERV-related sequences indicates that the mouse may be a useful model for studying some patterns of HERV regulation. Overall, the available evidence identifies the diverse, potential interactions with endogenous or exogenous factors as a promising field for investigating the roles of ERVs in physiology and disease.
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Affiliation(s)
- D Taruscio
- National Centre on Rare Diseases, Istituto Superiore di Sanità, Rome, Italy
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Christensen T. Association of human endogenous retroviruses with multiple sclerosis and possible interactions with herpes viruses. Rev Med Virol 2005; 15:179-211. [PMID: 15782388 DOI: 10.1002/rmv.465] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The hypothesis that human endogenous retroviruses (HERVs) play a role in autoimmune diseases is subject to increasing attention. HERVs represent both putative susceptibility genes and putative pathogenic viruses in the immune-mediated neurological disease multiple sclerosis (MS). Gammaretroviral HERV sequences are found in reverse transcriptase-positive virions produced by cultured mononuclear cells from MS patients, and they have been isolated from MS samples of plasma, serum and CSF, and characterised to some extent at the nucleotide, protein/enzyme, virion and immunogenic level. Two types of sequences, HERV-H and HERV-W, have been reported. No known HERV-H or HERV-W copy contains complete ORFs in all prerequisite genes, although several copies have coding potential, and several such sequences are specifically activated in MS, apparently resulting in the production of complete, competent virions. Increased antibody reactivity to specific Gammaretroviral HERV epitopes is found in MS serum and CSF, and cell-mediated immune responses have also been reported. Further, HERV-encoded proteins can have neuropathogenic effects. The activating factor(s) in the process resulting in protein or virion production may be members of the Herpesviridae. Several herpes viruses, such as HSV-1, VZV, EBV and HHV-6, have been associated with MS pathogenesis, and retroviruses and herpes viruses have complex interactions. The current understanding of HERVs, and specifically the investigations of HERV activation and expression in MS are the major subjects of this review, which also proposes to synergise the herpes and HERV findings, and presents several possible pathogenic mechanisms for HERVs in MS.
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Affiliation(s)
- Tove Christensen
- Institute of Medical Microbiology and Immunology, Bartholin Building, University of Aarhus, DK-8000 Aarhus C, Denmark.
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Nelson PN, Hooley P, Roden D, Davari Ejtehadi H, Rylance P, Warren P, Martin J, Murray PG. Human endogenous retroviruses: transposable elements with potential? Clin Exp Immunol 2004; 138:1-9. [PMID: 15373898 PMCID: PMC1809191 DOI: 10.1111/j.1365-2249.2004.02592.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/06/2004] [Indexed: 12/20/2022] Open
Abstract
Human endogenous retroviruses (HERVs) are a significant component of a wider family of retroelements that constitute part of the human genome. These viruses, perhaps representative of previous exogenous retroviral infection, have been integrated and passed through successive generations within the germ line. The retention of HERVs and isolated elements, such as long-terminal repeats, could have the potential to harm. In this review we describe HERVs within the context of the family of known transposable elements and survey these viruses in terms of superantigens and molecular mimics. It is entirely possible that these mechanisms provide the potential for undesired immune responses.
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Affiliation(s)
- P N Nelson
- Research Institute in Healthcare Science, University of Wolverhampton, UK.
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Bannert N, Kurth R. Retroelements and the human genome: new perspectives on an old relation. Proc Natl Acad Sci U S A 2004; 101 Suppl 2:14572-9. [PMID: 15310846 PMCID: PMC521986 DOI: 10.1073/pnas.0404838101] [Citation(s) in RCA: 371] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retroelements constitute a large portion of our genomes. One class of these elements, the human endogenous retroviruses (HERVs), is comprised of remnants of ancient exogenous retroviruses that have gained access to the germ line. After integration, most proviruses have been the subject of numerous amplifications and have suffered extensive deletions and mutations. Nevertheless, HERV-derived transcripts and proteins have been detected in healthy and diseased human tissues, and HERV-K, the youngest, most conserved family, is able to form virus-like particles. Although it is generally accepted that the integration of retroelements can cause significant harm by disrupting or disregulating essential genes, the role of HERV expression in the etiology of malignancies and autoimmune and neurologic diseases remains controversial. In recent years, striking evidence has accumulated indicating that some proviral sequences and HERV proteins might even serve the needs of the host and are therefore under positive selection. The remarkable progress in the analysis of host genomes has brought to light the significant impact of HERVs and other retroelements on genetic variation, genome evolution, and gene regulation.
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Wang SR, Chang JT, Lin MS, Chiang CY, Chang HY. Establishing the reactivity of monoclonal antibodies against porcine endogenous retrovirus envelope protein. Intervirology 2004; 47:93-101. [PMID: 15192273 DOI: 10.1159/000077832] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2003] [Accepted: 10/14/2003] [Indexed: 11/19/2022] Open
Abstract
Xenotransplantation of pig organs may be associated with a risk of transmission of microorganisms. Porcine endogenous retroviruses (PERV) are of particular concern since in vitro experiments have demonstrated that human cells are susceptible to such microorganisms. To monitor the transmission of PERV, highly sensitive and specific immunoassays must be developed for clinical surveillance. This report describes the production, preliminary characterization and application of a monoclonal antibody (mAb) against a recombinant PERV envelope (Env) protein. The generated mAb was tested using recombinant PERV Env protein expressed in Escherichia coli, purified PERV virus particles and human 293 cell line infected with PERV. PERV-translated proteins of 15, 70 and 85 kD were recognized specifically using PERV-8E10 mAb and Western blotting. No cross-reactivity was demonstrated with exogenous viral protein (HIV, HTLV and MuLV). Moreover, PERV-8E10 mAb can be applied to localize PERV proteins using an immunoperoxidase assay. This work reveals that recombinant PERV Env protein and mAb may be effective in detecting antibodies against PERV in xenotransplanted patients, or for butchers who have extensive contact with pigs.
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Affiliation(s)
- Shih-Rong Wang
- Division of Biotechnology, Animal Technology Institute Taiwan, Taiwan, ROC.
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Nelson PN, Westwood OMR, Soltys A, Jefferis R, Goodall M, Baumforth KRN, Frampton G, Tribbick G, Roden D, Hay FC. Characterisation of epitopes of pan-IgG/anti-G3m(u) and anti-Fc monoclonal antibodies. Immunol Lett 2003; 88:77-83. [PMID: 12853166 DOI: 10.1016/s0165-2478(03)00056-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The characterisation of monoclonal antibodies (MAbs) and their epitopes is important prior to their application as molecular probes. In this study, Western blotting using IgG1 Fc and pFc' fragments was employed to screen seven MAbs before pepscan analysis to determine their reactivity to potentially linear epitopes. MAbs PNF69C, PNF110A, X1A11 and MAbs WC2, G7C, JD312, 1A1 detected epitopes within the C(H)3 and C(H)2 domains, respectively. However, only four MAbs showed pepscan profiles that highlighted likely target residues. In particular, MAbs PNF69C and PNF110A that have previously been characterised with pan-IgG and anti-G3m(u) specificity, detected the peptide motif 338-KAKGQPR-344 which was located within the N-terminal region of the C(H)3 domain. Furthermore the majority of residues were present in all four IgG subclasses. Consequently the peptide identified was consistent with the pan-IgG nature of these antibodies. By using PCImdad, a molecular display programme, this sequence was visualised as surface accessible, located in the C(H)2/C(H)3 inter-domain region and proximal to the residue arginine(435). It is speculated that this residue may be important for phenotypic expression of G3m(u) and specificity of these reagents. Pepscan analysis of MAbs G7C and JD312 (both pan-IgG) highlighted the core peptide sequence 290-KPREE-294, which was present in the C(H)2 domain and was common to all four IgG subclasses. PCImdad also showed this region to be highly accessible and was consistent with previous bioinformatic and autoimmune analysis of IgG. Overall these MAbs may serve as useful anti-IgG or anti-G3m(u) reagents and probes of immunoglobulin structure.
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Affiliation(s)
- Paul N Nelson
- Molecular Immunology Research Group, Division of Biomedical Sciences, University of Wolverhampton, Wulfruna Street, Wolverhampton, WV1 1SB, UK.
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