1
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Collin V, Flamand L. [The importance of telomeres in human herpesvirus-6A/B infections]. Med Sci (Paris) 2022; 38:168-176. [PMID: 35179471 DOI: 10.1051/medsci/2022008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Herpesviruses are undisputed masters of disguise. The ability to become invisible to the immune system effectors is a complex process resting on a variety of stealth approaches. Among these, human herpesviruses-6A and -6B (HHV-6A/B) have developed the unique ability to integrate their genome within the ends of chromosomes allowing viral persistence in the absence of viral protein expression. This aptitude, unique to HHV-6A/B among human herpesviruses, requires close interactions between the telomeric regions of chromosomes and the viral genome. In this review article, the biology of telomeres and the mechanisms responsible for viral integration are discussed. In closing, the possible biological consequences of HHV-6A/B integration into chromosomal DNA are discussed.
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Affiliation(s)
- Vanessa Collin
- Axe des maladies infectieuses et immunitaires, Centre de recherche du CHU de Québec - Université Laval, Québec, 2705 boulevard Laurier, Québec, Canada
| | - Louis Flamand
- Axe des maladies infectieuses et immunitaires, Centre de recherche du CHU de Québec - Université Laval, Québec, 2705 boulevard Laurier, Québec, Canada - Département de microbiologie, maladies infectieuses et immunologie, Faculté de médecine, Université Laval, Québec, 2705 boulevard Laurier, Québec, Canada
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2
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Kumaran U, Gaonkar S, Chaudhuri M, Sheriff AK, Rao N, Raja M, Shenoi A. Chromosomally integrated human herpes virus 6A-associated myocarditis in a neonate treated with artesunate. J Paediatr Child Health 2021; 57:1998-2000. [PMID: 33624360 DOI: 10.1111/jpc.15391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/20/2021] [Accepted: 01/29/2021] [Indexed: 12/29/2022]
Affiliation(s)
- Uthaya Kumaran
- Department of Pediatrics, Cloudnine Hospital, Bangalore, India
| | - Seema Gaonkar
- Department of Pediatrics, Cloudnine Hospital, Bangalore, India
| | | | - Ajmeer K Sheriff
- 3i Molecular Solutions and Healthcare Services Pvt Ltd, Bangalore, India
| | - Nilesh Rao
- Department of Pediatrics, Cloudnine Hospital, Bangalore, India
| | - Malathi Raja
- Department of Pediatrics, Cloudnine Hospital, Bangalore, India
| | - Arvind Shenoi
- Department of Pediatrics, Cloudnine Hospital, Bangalore, India
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3
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Aswad A, Aimola G, Wight D, Roychoudhury P, Zimmermann C, Hill J, Lassner D, Xie H, Huang ML, Parrish NF, Schultheiss HP, Venturini C, Lager S, Smith GCS, Charnock-Jones DS, Breuer J, Greninger AL, Kaufer BB. Evolutionary History of Endogenous Human Herpesvirus 6 Reflects Human Migration out of Africa. Mol Biol Evol 2021; 38:96-107. [PMID: 32722766 PMCID: PMC7782865 DOI: 10.1093/molbev/msaa190] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human herpesvirus 6A and 6B (HHV-6) can integrate into the germline, and as a result, ∼70 million people harbor the genome of one of these viruses in every cell of their body. Until now, it has been largely unknown if 1) these integrations are ancient, 2) if they still occur, and 3) whether circulating virus strains differ from integrated ones. Here, we used next-generation sequencing and mining of public human genome data sets to generate the largest and most diverse collection of circulating and integrated HHV-6 genomes studied to date. In genomes of geographically dispersed, only distantly related people, we identified clades of integrated viruses that originated from a single ancestral event, confirming this with fluorescent in situ hybridization to directly observe the integration locus. In contrast to HHV-6B, circulating and integrated HHV-6A sequences form distinct clades, arguing against ongoing integration of circulating HHV-6A or “reactivation” of integrated HHV-6A. Taken together, our study provides the first comprehensive picture of the evolution of HHV-6, and reveals that integration of heritable HHV-6 has occurred since the time of, if not before, human migrations out of Africa.
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Affiliation(s)
- Amr Aswad
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Giulia Aimola
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Darren Wight
- Institut für Virologie, Freie Universität Berlin, Berlin, Germany
| | - Pavitra Roychoudhury
- Department of Laboratory Medicine, University of Washington, Seattle, WA.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Centre, Seattle, WA
| | | | - Joshua Hill
- Department of Laboratory Medicine, University of Washington, Seattle, WA.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Centre, Seattle, WA.,Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Dirk Lassner
- HighTech Center, Vinmec Hospital, Hanoi, Vietnam.,Institut Kardiale Diagnostik und Therapie, Berlin, Germany
| | - Hong Xie
- Department of Laboratory Medicine, University of Washington, Seattle, WA.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Centre, Seattle, WA
| | - Meei-Li Huang
- Department of Laboratory Medicine, University of Washington, Seattle, WA.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Centre, Seattle, WA
| | - Nicholas F Parrish
- Genome Immunobiology RIKEN Hakubi Research Team, RIKEN Cluster for Pioneering Research, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | | | - Cristina Venturini
- Division of Infection and Immunity, UCL Research Department of Infection, UCL, London, United Kingdom
| | - Susanne Lager
- Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.,Department of Obstetrics and Gynaecology, Cambridge University, United Kingdom
| | - Gordon C S Smith
- Department of Obstetrics and Gynaecology, Cambridge University, United Kingdom
| | | | - Judith Breuer
- Division of Infection and Immunity, UCL Research Department of Infection, UCL, London, United Kingdom
| | - Alexander L Greninger
- Department of Laboratory Medicine, University of Washington, Seattle, WA.,Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Centre, Seattle, WA
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4
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Forni D, Cagliani R, Clerici M, Pozzoli U, Sironi M. Evolutionary analysis of exogenous and integrated HHV-6A/HHV-6B populations. Virus Evol 2020; 6:veaa035. [PMID: 32551136 PMCID: PMC7293831 DOI: 10.1093/ve/veaa035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Human betaherpesviruses 6A and 6B (HHV-6A and HHV-6B) are highly prevalent in human populations. The genomes of these viruses can be stably integrated at the telomeres of human chromosomes and be vertically transmitted (inherited chromosomally integrated HHV-6A/HHV-6B, iciHHV-6A/iciHHV-6B). We reconstructed the population structures of HHV-6A and HHV-6B, showing that HHV-6A diverged less than HHV-6B genomes from the projected common ancestral population. Thus, HHV-6B genomes experienced stronger drift, as also supported by calculation of nucleotide diversity and Tajima's D. Analysis of ancestry proportions indicated that HHV-6A exogenous viruses and iciHHV-6A derived most of their genomes from distinct ancestral sources. Conversely, ancestry proportions were similar in exogenous HHV-6B viruses and iciHHV-6B. In line with previous indications, this suggests the distinct exogenous viral populations that originated iciHHV-6B in subjects with European and Asian ancestry are still causing infections in the corresponding geographic areas. Notably, for both iciHHV-6A and iciHHV-6B, we found that European and American sequences tend to have high proportions of ancestry from viral populations that experienced considerable drift, suggesting that they underwent one or more bottlenecks followed by population expansion. Finally, analysis of HHV-6B exogenous viruses sampled in Japan indicated that proportions of ancestry components of most of these viruses are different from the majority of those sampled in the USA. More generally, we show that, in both viral species, both integrated and exogenous viral genomes have different ancestry components, partially depending on geographic location. It would be extremely important to determine whether such differences account for the diversity of HHV-6A/HHV-6B-associated clinical symptoms and epidemiology. Also, the sequencing of additional exogenous and integrated viral genomes will be instrumental to confirm and expand our conclusions, which are based on a relatively small number of genomes, sequenced with variable quality, and with unequal sampling in terms of geographic origin.
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Affiliation(s)
- Diego Forni
- Bioinformatics, Scientific Institute IRCCS E. MEDEA, 23842 Bosisio Parini, Lecco, Italy
| | - Rachele Cagliani
- Bioinformatics, Scientific Institute IRCCS E. MEDEA, 23842 Bosisio Parini, Lecco, Italy
| | - Mario Clerici
- Department of Physiopathology and Transplantation, University of Milan, 20090 Milan, Italy.,IRCCS Fondazione Don Carlo Gnocchi, 20148 Milan, Italy
| | - Uberto Pozzoli
- Bioinformatics, Scientific Institute IRCCS E. MEDEA, 23842 Bosisio Parini, Lecco, Italy
| | - Manuela Sironi
- Bioinformatics, Scientific Institute IRCCS E. MEDEA, 23842 Bosisio Parini, Lecco, Italy
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5
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Forni D, Cagliani R, Clerici M, Pozzoli U, Sironi M. A complex evolutionary relationship between HHV-6A and HHV-6B. Virus Evol 2019; 5:vez043. [PMID: 31649826 PMCID: PMC6800887 DOI: 10.1093/ve/vez043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Human betaherpesviruses 6A and 6B (HHV-6A and HHV-6B) are highly prevalent in human populations. The genomes of these viruses can be stably integrated at the telomeres of human chromosomes and be vertically transmitted (inherited chromosomally integrated HHV-6, iciHHV6). We reconstructed the population structure of HHV-6 and we show that HHV-6A genomes diverged less than HHV-6B genomes from the ancestral common HHV-6A/B population. Analysis of ancestry proportions indicated that HHV-6A exogenous viruses and iciHHV-6A derived most of their genomes from distinct ancestral sources. Conversely, exogenous viral and iciHHV-6B populations were similar in terms of ancestry components, with no evident geographic structuring. Most HHV-6B genomes sampled to date derive from viral populations that experienced considerable drift. However, a population of HHV-6 exogenous viruses, currently classified as HHV-6B and sampled in New York state, formed a separate cluster (NY cluster) and harbored a considerable portion of HHV-6A-like ancestry. Recombination detection methods identified these viruses as interspecies recombinants, but phylogenetic reconstruction indicated that the recombination signals are due to shared ancestry. In analogy to iciHHV-6A, NY cluster viruses have high nucleotide diversity and constant population size. We propose that HHV-6A sequences and the NY cluster population diverged from an ancestral HHV-6A-like population. A relatively recent bottleneck of the NY (or a related) population with subsequent expansion originated most HHV-6B genomes currently sampled. Our findings indicate that the distinction between HHV-6A and -6B is not as clear-cut as previously thought. More generally, epidemiological and clinical surveys would benefit from taking HHV-6 genetic diversity into account.
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Affiliation(s)
- Diego Forni
- Bioinformatics, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
- Corresponding author: E-mail:
| | - Rachele Cagliani
- Bioinformatics, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Mario Clerici
- Department of Physiopathology and Transplantation, University of Milan, Milan, Italy
- IRCCS Fondazione Don Carlo Gnocchi, Milan, Italy
| | - Uberto Pozzoli
- Bioinformatics, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Manuela Sironi
- Bioinformatics, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
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6
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Pontejo SM, Murphy PM. Chemokines encoded by herpesviruses. J Leukoc Biol 2017; 102:1199-1217. [PMID: 28848041 DOI: 10.1189/jlb.4ru0417-145rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 12/15/2022] Open
Abstract
Viruses use diverse strategies to elude the immune system, including copying and repurposing host cytokine and cytokine receptor genes. For herpesviruses, the chemokine system of chemotactic cytokines and receptors is a common source of copied genes. Here, we review the current state of knowledge about herpesvirus-encoded chemokines and discuss their possible roles in viral pathogenesis, as well as their clinical potential as novel anti-inflammatory agents or targets for new antiviral strategies.
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Affiliation(s)
- Sergio M Pontejo
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Philip M Murphy
- Laboratory of Molecular Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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7
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Collin V, Flamand L. HHV-6A/B Integration and the Pathogenesis Associated with the Reactivation of Chromosomally Integrated HHV-6A/B. Viruses 2017; 9:E160. [PMID: 28672870 PMCID: PMC5537652 DOI: 10.3390/v9070160] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 01/03/2023] Open
Abstract
Unlike other human herpesviruses, human herpesvirus 6A and 6B (HHV-6A/B) infection can lead to integration of the viral genome in human chromosomes. When integration occurs in germinal cells, the integrated HHV-6A/B genome can be transmitted to 50% of descendants. Such individuals, carrying one copy of the HHV-6A/B genome in every cell, are referred to as having inherited chromosomally-integrated HHV-6A/B (iciHHV-6) and represent approximately 1% of the world's population. Interestingly, HHV-6A/B integrate their genomes in a specific region of the chromosomes known as telomeres. Telomeres are located at chromosomes' ends and play essential roles in chromosomal stability and the long-term proliferative potential of cells. Considering that the integrated HHV-6A/B genome is mostly intact without any gross rearrangements or deletions, integration is likely used for viral maintenance into host cells. Knowing the roles played by telomeres in cellular homeostasis, viral integration in such structure is not likely to be without consequences. At present, the mechanisms and factors involved in HHV-6A/B integration remain poorly defined. In this review, we detail the potential biological and medical impacts of HHV-6A/B integration as well as the possible chromosomal integration and viral excision processes.
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Affiliation(s)
- Vanessa Collin
- Division of Infectious and Immune Diseases, CHU de Quebec Research Center-Laval University, Québec, QC G1V 4G2, Canada.
| | - Louis Flamand
- Division of Infectious and Immune Diseases, CHU de Quebec Research Center-Laval University, Québec, QC G1V 4G2, Canada.
- Department of Microbiology, Infectious Disease and Immunology, Faculty of Medicine, Laval University, Québec, QC G1V 0A6, Canada.
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8
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Tweedy J, Spyrou MA, Pearson M, Lassner D, Kuhl U, Gompels UA. Complete Genome Sequence of Germline Chromosomally Integrated Human Herpesvirus 6A and Analyses Integration Sites Define a New Human Endogenous Virus with Potential to Reactivate as an Emerging Infection. Viruses 2016; 8:v8010019. [PMID: 26784220 PMCID: PMC4728579 DOI: 10.3390/v8010019] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/25/2015] [Accepted: 12/01/2015] [Indexed: 12/23/2022] Open
Abstract
Human herpesvirus-6A and B (HHV-6A, HHV-6B) have recently defined endogenous genomes, resulting from integration into the germline: chromosomally-integrated “CiHHV-6A/B”. These affect approximately 1.0% of human populations, giving potential for virus gene expression in every cell. We previously showed that CiHHV-6A was more divergent than CiHHV-6B by examining four genes in 44 European CiHHV-6A/B cardiac/haematology patients. There was evidence for gene expression/reactivation, implying functional non-defective genomes. To further define the relationship between HHV-6A and CiHHV-6A we used next-generation sequencing to characterize genomes from three CiHHV-6A cardiac patients. Comparisons to known exogenous HHV-6A showed CiHHV-6A genomes formed a separate clade; including all 85 non-interrupted genes and necessary cis-acting signals for reactivation as infectious virus. Greater single nucleotide polymorphism (SNP) density was defined in 16 genes and the direct repeats (DR) terminal regions. Using these SNPs, deep sequencing analyses demonstrated superinfection with exogenous HHV-6A in two of the CiHHV-6A patients with recurrent cardiac disease. Characterisation of the integration sites in twelve patients identified the human chromosome 17p subtelomere as a prevalent site, which had specific repeat structures and phylogenetically related CiHHV-6A coding sequences indicating common ancestral origins. Overall CiHHV-6A genomes were similar, but distinct from known exogenous HHV-6A virus, and have the capacity to reactivate as emerging virus infections.
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Affiliation(s)
- Joshua Tweedy
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, University of London, London WC1E 7HT, UK.
| | - Maria Alexandra Spyrou
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, University of London, London WC1E 7HT, UK.
| | - Max Pearson
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, University of London, London WC1E 7HT, UK.
| | - Dirk Lassner
- Institute of Cardiac diagnostics (IKDT), Charite University, D-12203 Berlin, Germany.
| | - Uwe Kuhl
- Institute of Cardiac diagnostics (IKDT), Charite University, D-12203 Berlin, Germany.
| | - Ursula A Gompels
- Department of Pathogen Molecular Biology, London School of Hygiene & Tropical Medicine, University of London, London WC1E 7HT, UK.
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