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Coinfection of Dermal Fibroblasts by Human Cytomegalovirus and Human Herpesvirus 6 Can Boost the Expression of Fibrosis-Associated MicroRNAs. Microorganisms 2023; 11:microorganisms11020412. [PMID: 36838377 PMCID: PMC9958881 DOI: 10.3390/microorganisms11020412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/01/2023] [Accepted: 02/04/2023] [Indexed: 02/10/2023] Open
Abstract
Tissue fibrosis can affect every type of tissue or organ, often leading to organ malfunction; however, the mechanisms involved in this process are not yet clarified. A role has been hypothesized for Human Cytomegalovirus (HCMV) and Human Herpesvirus 6 (HHV-6) infections as triggers of systemic sclerosis (SSc), a severe autoimmune disease causing progressive tissue fibrosis, since both viruses and antiviral immune responses toward them have been detected in patients. Moreover, HCMV or HHV-6A infection was reported to increase the expression of fibrosis-associated transcriptional factors and miRNAs in human dermal fibroblasts. However, it is unlikely that they have separate effects in the infected host, as both viruses are highly prevalent in the human population. Thus, our study aimed to investigate, by quantitative real-time PCR microarray, the impact of HCMV/HHV-6A coinfection on the expression of pro-fibrotic miRNAs in coinfected cells, compared to the effect of single viruses. The results showed a possible synergistic effect of the two viruses on pro-fibrotic miRNA expression, thus suggesting that HCMV and HHV-6 may enhance each other and cooperate at inducing enhanced miRNA-driven fibrosis. These data may also suggest a possible use of virus-induced miRNAs as novel diagnostic or prognostic biomarkers for SSc and its clinical treatment.
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Hogestyn JM, Salois G, Xie L, Apa C, Youngyunpipatkul J, Pröschel C, Mayer-Pröschel M. Expression of the human herpesvirus 6A latency-associated transcript U94A impairs cytoskeletal functions in human neural cells. Mol Cell Neurosci 2022; 123:103770. [PMID: 36055520 PMCID: PMC10124163 DOI: 10.1016/j.mcn.2022.103770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/12/2022] [Accepted: 08/20/2022] [Indexed: 12/30/2022] Open
Abstract
Many neurodegenerative diseases have a multifactorial etiology and variable course of progression that cannot be explained by current models. Neurotropic viruses have long been suggested to play a role in these diseases, although their exact contributions remain unclear. Human herpesvirus 6A (HHV-6A) is one of the most common viruses detected in the adult brain, and has been clinically associated with multiple sclerosis (MS), and, more recently, Alzheimer's disease (AD). HHV-6A is a ubiquitous viral pathogen capable of infecting glia and neurons. Primary infection in childhood is followed by the induction of latency, characterized by expression of the U94A viral transcript in the absence of viral replication. Here we examine the effects of U94A on cells of the central nervous system. We found that U94A expression inhibits the migration and impairs cytoplasmic maturation of human oligodendrocyte precursor cells (OPCs) without affecting their viability, a phenotype that may contribute to the failure of remyelination seen in many patients with MS. A subsequent proteomics analysis of U94A expression OPCs revealed altered expression of genes involved in tubulin associated cytoskeletal regulation. As HHV-6A seems to significantly be associated with early AD pathology, we extended our initially analysis of the impact of U94A on human derived neurons. We found that U94A expression inhibits neurite outgrowth of primary human cortical neurons and impairs synapse maturation. Based on these data we suggest that U94A expression by latent HHV-6A in glial cells and neurons renders them susceptible to dysfunction and degeneration. Therefore, latent viral infections of the brain represent a unique pathological risk factor that may contribute to disease processes.
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Affiliation(s)
- Jessica M Hogestyn
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA; Department of Neuroscience, School of Medicine and Dentistry, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Garrick Salois
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA; Department of Neuroscience, School of Medicine and Dentistry, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Li Xie
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Connor Apa
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA; Stem cell and Regenerative Medicine Institute, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Justin Youngyunpipatkul
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Christoph Pröschel
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA; Stem cell and Regenerative Medicine Institute, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA
| | - Margot Mayer-Pröschel
- Department of Biomedical Genetics, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA; Department of Neuroscience, School of Medicine and Dentistry, 601 Elmwood Avenue, Box 633, University of Rochester, Rochester, NY 14642, USA,.
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3
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Wang JQ, Yang HY, Shao X, Jiang XY, Li JM. Latent, Early or Late Human Herpes Virus-6B Expression in Adult Mesial Temporal Lobe Epilepsy: Association of Virus Life Cycle with Inflammatory Cytokines in Brain Tissue and Cerebral Spinal Fluid. Neuroscience 2022; 504:21-32. [PMID: 36067950 DOI: 10.1016/j.neuroscience.2022.08.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/08/2022] [Accepted: 08/25/2022] [Indexed: 10/31/2022]
Abstract
BACKGROUND Human herpes virus-6B (HHV-6B) was suggested as an important etiologic factor of mesial temporal lobe epilepsy, while the mechanism is still unknown. Here, we aimed to analyze antigens representing latent, early and late HHV-6B infection and the association with inflammatory cytokines in brain tissue and cerebral spinal fluid (CSF) from MTLE patients with HHV-6B-positivity. METHODS Nested polymerase chain reaction (nPCR), real-time PCR, immunohistochemistry (ICH) and suspension bead array for cytokines were performed. RESULTS Nested polymerase chain reaction (nPCR) in brain tissue revealed HHV-6B DNA in 19 of 49 MTLE patients (39%) and 1 of 19 controls (5%) (P < 0.001), but not in CSF. ICH showed HHV-6B early antigen (P41) positivity in 3 patients (6%), late antigen (gp116/54/64) positivity in 5 patients (10%), latent antigen (U94) positivity in 8 patients (16%), and multiple antigen (early and late or/and latent) positivity in 9 patients (18%). None of these HHV-6B related proteins were found positive in control brain tissue. PCR revealed significant up-regulation of IL-1a, IL-2 and IL-7 mRNA levels in the brain tissue from MTLE patients expressing early antigens compared to those expressing late, latent, multiple antigens, negative antigens and the controls. Suspension bead array of the CSF confirmed significant up-regulation of IL-1a and IL-7 protein expression from MTLE patients expressing early antigens compared to the other groups. CONCLUSIONS Our finding suggests HHV-6B is a common etiologic agent of MTLE. Different virus life cycle may play an important modifying role in inflammatory biology that warrants further investigation. Though virus DNA is difficult detected in CSF, up-regulation of IL-1a and IL-7 in CSF indicates the two cytokines may be taken as indirect biomarker of HHV-6B infection.
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Affiliation(s)
- Jia-Qi Wang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Hong-Yu Yang
- University of Electronic Science and Technology of China Hospital, China
| | | | - Xin-Yue Jiang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Chengdu Second People's Hospital, Chengdu, Sichuan Province, China
| | - Jin-Mei Li
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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4
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Human Cytomegalovirus and Human Herpesvirus 6 Coinfection of Dermal Fibroblasts Enhances the Pro-Inflammatory Pathway Predisposing to Fibrosis: The Possible Impact on Systemic Sclerosis. Microorganisms 2022; 10:microorganisms10081600. [PMID: 36014018 PMCID: PMC9415275 DOI: 10.3390/microorganisms10081600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/02/2022] [Accepted: 08/06/2022] [Indexed: 11/16/2022] Open
Abstract
Systemic sclerosis (SSc) is a severe autoimmune disease likely triggered by genetic and environmental factors, including viral infections. Human cytomegalovirus (HCMV) and human herpesvirus 6A species (HHV-6A) have been associated with SSc, based on in vivo and in vitro evidence, but the data are still inconclusive. Furthermore, despite both viruses being highly prevalent in humans and able to exacerbate each other’s effects, no data are available on their joint effects. Hence, we aimed to study their simultaneous impact on the expression of cell factors correlated with fibrosis and apoptosis in in vitro coinfected fibroblasts, representing the main target cell type in SSc. The results, obtained by a microarray detecting 84 fibrosis/apoptosis-associated factors, indicated that coinfected cells underwent higher and more sustained expression of fibrosis-associated parameters compared with single-infected cells. Thus, the data, for the first time, suggest that HCMV and HHV-6A may cooperate in inducing alterations potentially leading to cell fibrosis, thus further supporting their joint role in SSc. However, further work is required to definitively answer whether β-herpesviruses are causally linked to the disease and to enable the possible use of targeted antiviral treatments to improve clinical outcomes.
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Ferri C, Arcangeletti MC, Caselli E, Zakrzewska K, Maccari C, Calderaro A, D'Accolti M, Soffritti I, Arvia R, Sighinolfi G, Artoni E, Giuggioli D. Insights into the knowledge of complex diseases: Environmental infectious/toxic agents as potential etiopathogenetic factors of systemic sclerosis. J Autoimmun 2021; 124:102727. [PMID: 34601207 DOI: 10.1016/j.jaut.2021.102727] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/16/2021] [Accepted: 09/17/2021] [Indexed: 12/14/2022]
Abstract
Systemic sclerosis (SSc) is a connective tissue disease secondary to three cardinal pathological features: immune-system alterations, diffuse microangiopathy, and fibrosis involving the skin and internal organs. The etiology of SSc remains quite obscure; it may encompass multiple host genetic and environmental -infectious/chemical-factors. The present review focused on the potential role of environmental agents in the etiopathogenesis of SSc based on epidemiological, clinical, and laboratory investigations previously published in the world literature. Among infectious agents, some viruses that may persist and reactivate in infected individuals, namely human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and parvovirus B19 (B19V), and retroviruses have been proposed as potential causative agents of SSc. These viruses share a number of biological activities and consequent pathological alterations, such as endothelial dysfunction and/or fibroblast activation. Moreover, the acute worsening of pre-existing interstitial lung involvement observed in SSc patients with symptomatic SARS-CoV-2 infection might suggest a potential role of this virus in the overall disease outcome. A variety of chemical/occupational agents might be regarded as putative etiological factors of SSc. In this setting, the SSc complicating silica dust exposure represents one of the most promising models of study. Considering the complexity of SSc pathogenesis, none of suggested causative factors may explain the appearance of the whole SSc; it is likely that the disease is the result of a multifactorial and multistep pathogenetic process. A variable combination of potential etiological factors may modulate the appearance of different clinical phenotypes detectable in individual scleroderma patients. The in-deep investigations on the SSc etiopathogenesis may provide useful insights in the broad field of human diseases characterized by diffuse microangiopathy or altered fibrogenesis.
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Affiliation(s)
- Clodoveo Ferri
- Rheumatology Unit, Medical School, University of Modena and Reggio E, University-Hospital Policlinico of Modena, Modena, Italy; Rheumatology Unit, Casa di Cura Madonna dello Scoglio, Cotronei (KR), Italy.
| | | | - Elisabetta Caselli
- Section of Microbiology, Department of Chemical, Pharmaceutical and Agricultural Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Krystyna Zakrzewska
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Clara Maccari
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Adriana Calderaro
- Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - Maria D'Accolti
- Section of Microbiology, Department of Chemical, Pharmaceutical and Agricultural Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Irene Soffritti
- Section of Microbiology, Department of Chemical, Pharmaceutical and Agricultural Sciences and LTTA, University of Ferrara, Ferrara, Italy
| | - Rosaria Arvia
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Gianluca Sighinolfi
- Rheumatology Unit, Medical School, University of Modena and Reggio E, University-Hospital Policlinico of Modena, Modena, Italy.
| | - Erica Artoni
- Rheumatology Unit, Medical School, University of Modena and Reggio E, University-Hospital Policlinico of Modena, Modena, Italy
| | - Dilia Giuggioli
- Rheumatology Unit, Medical School, University of Modena and Reggio E, University-Hospital Policlinico of Modena, Modena, Italy
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Modulation of microRNome by Human Cytomegalovirus and Human Herpesvirus 6 Infection in Human Dermal Fibroblasts: Possible Significance in the Induction of Fibrosis in Systemic Sclerosis. Cells 2021; 10:cells10051060. [PMID: 33946985 PMCID: PMC8146000 DOI: 10.3390/cells10051060] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 02/07/2023] Open
Abstract
Human cytomegalovirus (HCMV) and Human herpesvirus 6 (HHV-6) have been reportedly suggested as triggers of the onset and/or progression of systemic sclerosis (SSc), a severe autoimmune disorder characterized by multi-organ fibrosis. The etiology and pathogenesis of SSc are still largely unknown but virological and immunological observations support a role for these beta-herpesviruses, and we recently observed a direct impact of HCMV and HHV-6 infection on the expression of cell factors associated with fibrosis at the cell level. Since miRNA expression has been found profoundly deregulated at the tissue level, here we aimed to investigate the impact on cell microRNome (miRNome) of HCMV and HHV-6 infection in in vitro infected primary human dermal fibroblasts, which represent one of the main SSc target cells. The analysis, performed by Taqman arrays detecting and quantifying 754 microRNAs (miRNAs), showed that both herpesviruses significantly modulated miRNA expression in infected cells, with evident early and late effects and deep modulation (>10 fold) of >40 miRNAs at each time post infection, including those previously recognized for their key function in fibrosis. The correlation between these in vitro results with in vivo observations is strongly suggestive of a role of HCMV and/or HHV-6 in the multistep pathogenesis of fibrosis in SSc and in the induction of fibrosis-signaling pathways finally leading to tissue fibrosis. The identification of specific miRNAs may open the way to their use as biomarkers for SSc diagnosis, assessment of disease progression and possible antifibrotic therapies.
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The U94 Gene of Human Herpesvirus 6: A Narrative Review of Its Role and Potential Functions. Cells 2020; 9:cells9122608. [PMID: 33291793 PMCID: PMC7762089 DOI: 10.3390/cells9122608] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 12/02/2020] [Accepted: 12/02/2020] [Indexed: 12/11/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) is a β-herpesvirus that is highly prevalent in the human population. HHV-6 comprises two recognized species (HHV-6A and HHV-6B). Despite different cell tropism and disease association, HHV-6A/B show high genome homology and harbor the conserved U94 gene, which is limited to HHV-6 and absent in all the other human herpesviruses. U94 has key functions in the virus life cycle and associated diseases, having demonstrated or putative roles in virus replication, integration, and reactivation. During natural infection, U94 elicits an immune response, and the prevalence and extent of the anti-U94 response are associated with specific diseases. Notably, U94 can entirely reproduce some virus effects at the cell level, including inhibition of cell migration, induction of cytokines and HLA-G expression, and angiogenesis inhibition, supporting a direct U94 role in the development of HHV-6-associated diseases. Moreover, specific U94 properties, such as the ability to modulate angiogenesis pathways, have been exploited to counteract cancer development. Here, we review the information available on this key HHV-6 gene, highlighting its potential uses.
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8
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Impact of Human Cytomegalovirus and Human Herpesvirus 6 Infection on the Expression of Factors Associated with Cell Fibrosis and Apoptosis: Clues for Implication in Systemic Sclerosis Development. Int J Mol Sci 2020; 21:ijms21176397. [PMID: 32899126 PMCID: PMC7504027 DOI: 10.3390/ijms21176397] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/26/2020] [Accepted: 08/31/2020] [Indexed: 02/07/2023] Open
Abstract
Systemic sclerosis (SSc) is a severe autoimmune disorder characterized by vasculopathy and multi-organ fibrosis; its etiology and pathogenesis are still largely unknown. Herpesvirus infections, particularly by human cytomegalovirus (HCMV) and human herpesvirus 6 (HHV-6), have been suggested among triggers of the disease based on virological and immunological observations. However, the direct impact of HCMV and/or HHV-6 infection on cell fibrosis and apoptosis at the cell microenvironment level has not yet been clarified. Thus, this study aimed to investigate the effects of HCMV and HHV-6 infection on the induction of pro-fibrosis or pro-apoptosis conditions in primary human dermal fibroblasts, one of the relevant SSc target cells. The analysis, performed by microarray in in vitro HCMV- or HHV-6-infected vs. uninfected cells, using specific panels for the detection of the main cellular factors associated with fibrosis or apoptosis, showed that both viruses significantly modified the expression of at least 30 pro-fibrotic and 20 pro-apoptotic factors. Notably, several recognized pro-fibrotic factors were highly induced, and most of them were reported to be involved in vivo in the multifactorial and multistep pathogenic process of SSc, thus suggesting a potential role of both HCMV and HHV-6.
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9
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Weidner-Glunde M, Kruminis-Kaszkiel E, Savanagouder M. Herpesviral Latency-Common Themes. Pathogens 2020; 9:E125. [PMID: 32075270 PMCID: PMC7167855 DOI: 10.3390/pathogens9020125] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 02/09/2020] [Accepted: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
Latency establishment is the hallmark feature of herpesviruses, a group of viruses, of which nine are known to infect humans. They have co-evolved alongside their hosts, and mastered manipulation of cellular pathways and tweaking various processes to their advantage. As a result, they are very well adapted to persistence. The members of the three subfamilies belonging to the family Herpesviridae differ with regard to cell tropism, target cells for the latent reservoir, and characteristics of the infection. The mechanisms governing the latent state also seem quite different. Our knowledge about latency is most complete for the gammaherpesviruses due to previously missing adequate latency models for the alpha and beta-herpesviruses. Nevertheless, with advances in cell biology and the availability of appropriate cell-culture and animal models, the common features of the latency in the different subfamilies began to emerge. Three criteria have been set forth to define latency and differentiate it from persistent or abortive infection: 1) persistence of the viral genome, 2) limited viral gene expression with no viral particle production, and 3) the ability to reactivate to a lytic cycle. This review discusses these criteria for each of the subfamilies and highlights the common strategies adopted by herpesviruses to establish latency.
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Affiliation(s)
- Magdalena Weidner-Glunde
- Department of Reproductive Immunology and Pathology, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Tuwima Str. 10, 10-748 Olsztyn, Poland; (E.K.-K.); (M.S.)
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10
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Current understanding of human herpesvirus 6 (HHV-6) chromosomal integration. Antiviral Res 2020; 176:104720. [PMID: 32044155 DOI: 10.1016/j.antiviral.2020.104720] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/21/2020] [Accepted: 01/23/2020] [Indexed: 12/12/2022]
Abstract
Human herpesvirus 6A (HHV-6A) and 6B (HHV-6B) are members of the genus Roseolovirus in the Betaherpesvirinae subfamily. HHV-6B infects humans in the first years of life, has a seroprevalence of more than 90% and causes Roseola Infantum, but less is known about HHV-6A. While most other herpesviruses maintain their latent genome as a circular episome, HHV-6A and HHV-6B (HHV-6A/B) have been shown to integrate their genome into the telomeres of infected cells. HHV-6A/B can also integrate into the chromosomes of germ cells, resulting in individuals carrying a copy of the virus genome in every nucleated cell of their bodies. This review highlights our current understanding of HHV-6A/B integration and reactivation as well as aspects that should be addressed in the future of this relatively young research area. It forms part of an online symposium on the prevention and therapy of DNA virus infections, dedicated to the memory of Mark Prichard.
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Caselli E, Soffritti I, D’Accolti M, Bortolotti D, Rizzo R, Sighinolfi G, Giuggioli D, Ferri C. HHV-6A Infection and Systemic Sclerosis: Clues of a Possible Association. Microorganisms 2019; 8:microorganisms8010039. [PMID: 31878218 PMCID: PMC7022325 DOI: 10.3390/microorganisms8010039] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022] Open
Abstract
Systemic sclerosis (SSc) is an autoimmune disease characterized by vasculopathy, excessive extracellular matrix deposition, and fibrosis of the skin and internal organs. Several infectious agents, including human herpesvirus-6 (HHV-6), have been suggested as possible triggering factors, but a direct association is still missing. We characterized 26 SSc patients for the presence of HHV-6 in tissues and blood, the anti-HHV-6 response, HLA-G plasma levels, and KIR typing. Given the prominent role of endothelial cells (EC) in SSc pathogenesis, along with HHV-6 tropism for EC, we also investigated the expression of pro-fibrosis factors in HHV-6 infected EC. Results showed the presence of HHV-6A in skin biopsies, and an increased virus load was associated with disease severity and poor natural killer (NK) response against the virus, particularly in subjects exhibiting a KIR2 phenotype. HLA-G plasma levels were significantly higher in HHV-6A/B-KIR2 positive SSc patients and in vitro HHV-6A infection-induced pro-fibrosis factors expression in EC, supporting its role in the development of the fibrosing process. Our data suggest an association between virus infection/reactivation and disease, opening the way to future studies to understand the mechanisms by which HHV-6A might contribute to the multifactorial pathogenesis of SSc.
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Affiliation(s)
- Elisabetta Caselli
- Section of Microbiology and Medical Genetics, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy
- Correspondence: ; Tel.: +39-0532-455387
| | - Irene Soffritti
- Section of Microbiology and Medical Genetics, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Maria D’Accolti
- Section of Microbiology and Medical Genetics, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Daria Bortolotti
- Section of Microbiology and Medical Genetics, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Roberta Rizzo
- Section of Microbiology and Medical Genetics, Department of Chemical and Pharmaceutical Sciences, University of Ferrara, 44121 Ferrara, Italy
| | - Gianluca Sighinolfi
- Rheumatology Unit, Medical School, University of Modena and Reggio Emilia, University-Hospital Policlinico of Modena, 41121 Modena, Italy
| | - Dilia Giuggioli
- Rheumatology Unit, Medical School, University of Modena and Reggio Emilia, University-Hospital Policlinico of Modena, 41121 Modena, Italy
| | - Clodoveo Ferri
- Rheumatology Unit, Medical School, University of Modena and Reggio Emilia, University-Hospital Policlinico of Modena, 41121 Modena, Italy
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12
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Caccuri F, Sommariva M, Marsico S, Giordano F, Zani A, Giacomini A, Fraefel C, Balsari A, Caruso A. Inhibition of DNA Repair Mechanisms and Induction of Apoptosis in Triple Negative Breast Cancer Cells Expressing the Human Herpesvirus 6 U94. Cancers (Basel) 2019; 11:cancers11071006. [PMID: 31323788 PMCID: PMC6679437 DOI: 10.3390/cancers11071006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/01/2019] [Accepted: 07/11/2019] [Indexed: 12/18/2022] Open
Abstract
Triple-negative breast cancer (TNBC) accounts for 15–20% of all breast cancers. In spite of initial good response to chemotherapy, the prognosis of TNBC remains poor and no effective specific targeted therapy is readily available. Recently, we demonstrated the ability of U94, the latency gene of human herpes virus 6 (HHV-6), to interfere with proliferation and with crucial steps of the metastatic cascade by using MDA-MB 231 TNBC breast cancer cell line. U94 expression was also associated with a partial mesenchymal-to-epithelial transition (MET) of cells, which displayed a less aggressive phenotype. In this study, we show the ability of U94 to exert its anticancer activity on three different TNBC cell lines by inhibiting DNA damage repair genes, cell cycle and eventually leading to cell death following activation of the intrinsic apoptotic pathway. Interestingly, we found that U94 acted synergistically with DNA-damaging drugs. Overall, we provide evidence that U94 is able to combat tumor cells with different mechanisms, thus attesting for the great potential of this molecule as a multi-target drug in cancer therapy.
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Affiliation(s)
- Francesca Caccuri
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy
| | - Michele Sommariva
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan 20133, Italy
| | - Stefania Marsico
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza 87036, Italy
| | - Francesca Giordano
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Arcavacata di Rende, Cosenza 87036, Italy
| | - Alberto Zani
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy
| | - Arianna Giacomini
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy
| | - Cornel Fraefel
- Institute of Virology, University of Zurich, Zurich 8057, Switzerland
| | - Andrea Balsari
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan 20133, Italy
| | - Arnaldo Caruso
- Department of Molecular and Translational Medicine, University of Brescia, Brescia 25123, Italy.
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Human Herpesvirus 6A and 6B inhibit in vitro angiogenesis by induction of Human Leukocyte Antigen G. Sci Rep 2018; 8:17683. [PMID: 30523283 PMCID: PMC6283866 DOI: 10.1038/s41598-018-36146-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/09/2018] [Indexed: 11/08/2022] Open
Abstract
We have previously reported that human herpesvirus 6 (HHV-6) infection of endothelial cells (ECs) induces the loss of angiogenic properties, through the expression of HHV-6 U94, possibly associated to the release of a soluble mediator. It is also known that the soluble isoform of HLA-G exhibits an anti-angiogenic function, important in implantation, transplantation and neoplastic development. In this study, we analyzed the expression of HLA-G in HHV-6 infected ECs, showing that both HHV-6A and HHV-6B infection induce a potent up-modulation of HLA-G, including both membrane and soluble isoforms. Interestingly, HHV-6A and HHV-6B induced different isoforms of HLA-G. The virus-induced increase of HLA-G was likely due to the expression of the U94 viral gene, that by itself was able to reproduce the effect of whole virus. The effect of U94 was mediated by human transcription factor ATF3, that induced HLA-G activation by recognizing a consensus sequence on its promoter. Virus-induced inhibition of ECs angiogenic ability directly correlated to HLA-G expression and release, and the addition of anti-HLA-G antibody restored the angiogenic properties of HHV6-infected ECs. The induction of HLA-G expression in ECs might represent an important mediator of HHV-6 induced effects.
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Gu B, Li L, Li M, Wang J, Zhang G, Yao K, Wang S. U94/rep of human herpesvirus 6 inhibits proliferation, invasion, and angiogenesis of glioma. Cancer Manag Res 2018; 10:5991-6001. [PMID: 30538548 PMCID: PMC6254986 DOI: 10.2147/cmar.s177777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose We previously found the involvement of human herpesvirus 6 (HHV-6) infection in the pathogenesis of glioma. U94/rep, encoded by HHV-6, has been identified to play a vital role in viral gene expression and latency. Recent studies have shown its inhibition of angiogenesis and tumorigenesis in endothelial cells and prostate cancer cell line PC3, respectively. Here, we aimed to investigate the role of U94/rep in the development and progression of glioma. Patients and methods Patients and methods A total of 20 glioma tissues with positive HHV-6 infection were used for detection of U94/rep. MTT, soft agar, propidium iodide staining, wound healing, Transwell, and chick embryo chorioallantoic membrane assays were applied for evaluation of glioma cells’ proliferation, colony formation, cell cycle, migration, invasion, and angiogenesis, respectively. Results U94/rep transcripts could be detected in 11 out of 20 glioma tissues with positive HHV-6 infection. Furthermore, MTT and soft agar assays revealed that overexpression of U94/rep inhibited glioma cell proliferation and colony formation, which may be attributed to the cell cycle arrest at S phase induced by U94/rep. Further analysis demonstrated that U94/rep inhibited glioma cells’ migration and invasion and ex vivo angiogenesis. Reduced expression of proangiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, and type IV collagenases, MMP-2 and MMP-9, was detected in cells overexpressing U94/rep. These decreased factors may undermine glioma cell migration, invasion, and angiogenesis. Conclusion Our results demonstrated that U94/rep could inhibit malignant phenotypes of glioma cells, indicating that it is a potential target for therapeutic intervention.
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Affiliation(s)
- Bin Gu
- Department of Neurosurgery, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Lingyun Li
- Department of Developmental Genetics, Nanjing Medical University, Nanjing, China
| | - Meng Li
- Department of Neurosurgery, Suqian First Hospital, Suqian, China
| | - Jinfeng Wang
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, China
| | - Guofeng Zhang
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, China
| | - Kun Yao
- Department of Microbiology and Immunology, Nanjing Medical University, Nanjing, China
| | - Shizhi Wang
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China,
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Rizzo R, Soffritti I, D'Accolti M, Bortolotti D, Di Luca D, Caselli E. HHV-6A/6B Infection of NK Cells Modulates the Expression of miRNAs and Transcription Factors Potentially Associated to Impaired NK Activity. Front Microbiol 2017; 8:2143. [PMID: 29163428 PMCID: PMC5671584 DOI: 10.3389/fmicb.2017.02143] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/19/2017] [Indexed: 12/15/2022] Open
Abstract
Natural killer (NK) cells have a critical role in controlling virus infections, and viruses have evolved several mechanisms to escape NK cell functions. In particular, Human herpesvirus 6 (HHV-6) is associated with diseases characterized by immune dysregulation and has been reported to infect NK cells. We recently found that HHV-6 in vitro infection of human thyroid follicular epithelial cells and T-lymphocytes modulates several miRNAs associated with alterations in immune response. Since miRNAs are key regulators of many immune pathways, including NK cell functions, we aimed to study the impact of HHV-6A and -6B in vitro infection on the intracellular mediators correlated to NK cell function. To this purpose, a human NK cell line (NK-92) was infected in vitro with HHV-6A or 6B and analyzed for alterations in the expression of miRNAs and transcription factors. The results showed that both viruses establish lytic replication in NK-92 cells, as shown by the presence of viral DNA, expression of lytic transcripts and antigens, and by the induction of an evident cytopathic effect. Notably, both viruses, although with species-specific differences, induced significant modifications in miRNA expression of miRNAs known for their role in NK cell development, maturation and effector functions (miR-146, miR-155, miR-181, miR-223), and on at least 13 miRNAs with recognized role in inflammation and autoimmunity. Also the expression of transcription factors was significantly modified by HHV-6A/6B infection, with an early increase of ATF3, JUN and FOXA2 by both species, whereas HHV-6A specifically induced a 15-fold decrease of POU2AF1, and HHV-6B an increase of FOXO1 and a decrease of ESR1. Overall, our data show that HHV-6A and -6B infections have a remarkable effect on the expression of miRNAs and transcription factors, which might be important in the induction of NK cell function impairment, virus escape strategies and related pathologies.
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Affiliation(s)
- Roberta Rizzo
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Irene Soffritti
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Maria D'Accolti
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Daria Bortolotti
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Dario Di Luca
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Elisabetta Caselli
- Section of Microbiology and Medical Genetics, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
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16
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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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17
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HHV-6A in vitro infection of thyrocytes and T cells alters the expression of miRNA associated to autoimmune thyroiditis. Virol J 2017; 14:3. [PMID: 28081700 PMCID: PMC5234148 DOI: 10.1186/s12985-016-0672-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/15/2016] [Indexed: 11/10/2022] Open
Abstract
Background Human herpesviruses have been hypothesized as environmental triggers in the development of autoimmune thyroid diseases (AITD), and in particular active human herpesvirus 6A (HHV-6A) infection was detected in thyrocytes of Hashimoto’s thyroiditis (HT) patients, who also show specific anti-viral immune responses. On the other hand, AITD patients display modulation of specific miRNAs in thyroid tissue and blood. We wanted to ascertain whether HHV-6A infection might be correlated to the miRNA dysregulation observed in AITD. Methods Human thyroid and T-cell lines were infected in vitro with HHV-6A,-6B or −7, and analysed for miRNAs expression, either by microarray or by specific RT-PCR assays detecting miRNAs associated with AITD in vivo. Results HHV-6A infection, but not -6B or −7 infections, induced a decrease in miR-155_2 expression and an increase in miR-1238 expression in thyrocytes, as well as an increase in the expression levels of several autoimmunity-associated miRNAs in T lymphocytes, including miR-16_1, miR34a, miR-130a, miR-143_1, miR-202, miR-301b, miR-302c, miR-449b, miR-451_1, and miR-1238_2. Conclusions HHV-6A infection modulates miRNAs expression in the cell types involved in the development of AITD. Notably, our in vitro findings correlate with what observed in AITD patients, further supporting the association between HHV-6A infection and AITD development. Moreover, these effects are 6A-specific, emphasizing the differences between the two HHV-6 virus species, and suggesting diverse virus mechanisms of action and therapeutic approaches.
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18
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Abstract
Viruses are notorious for rapidly exchanging genetic information between close relatives and with the host cells they infect. This exchange has profound effects on the nature and rapidity of virus and host evolution. Recombination between dsDNA viruses is common, as is genetic exchange between dsDNA viruses or retroviruses and host genomes. Recombination between RNA virus genomes is also well known. In contrast, genetic exchange across viral kingdoms, for instance between nonretroviral RNA viruses or ssDNA viruses and host genomes or between RNA and DNA viruses, was previously thought to be practically nonexistent. However, there is now growing evidence for both RNA and ssDNA viruses recombining with host dsDNA genomes and, more surprisingly, RNA virus genes recombining with ssDNA virus genomes. Mechanisms are still unclear, but this deep recombination greatly expands the breadth of virus evolution and confounds virus taxonomy.
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Affiliation(s)
- Kenneth M Stedman
- Biology Department and Center for Life in Extreme Environments, Portland State University, Portland, Oregon 97207;
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19
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Acute human herpesvirus-6A infection of human mesothelial cells modulates HLA molecules. Arch Virol 2015; 160:2141-9. [PMID: 26085284 DOI: 10.1007/s00705-015-2490-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
Human herpesvirus 6A (HHV-6A) causes ubiquitous infections and has been associated with several diseases in immunosuppressed and immune dysregulated individuals. Although considered a lymphotropic virus, HHV-6A has the potential to infect many cell types, inducing important alterations in the infected cell. In our search for additional potential targets for HHV-6A infection, we analyzed the susceptibility of human mesothelial cells to viral infection. HHV-6A infection was performed and analyzed on primary human mesothelial cells isolated from serous cavity fluid, infected in vitro with a cell-free HHV-6A inoculum. The results demonstrated that mesothelial cells are susceptible to in vitro HHV-6A infection, and more importantly, that the virus induces an alteration of HLA expression on the cell surface, inducing HLA class II and HLA-G de novo expression. Since mesothelial cells play a pivotal role in many processes, including inflammation and antigen presentation, we speculate that, in vivo, this virus-induced perturbation might be correlated to alterations in mesothelium functions.
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Trempe F, Gravel A, Dubuc I, Wallaschek N, Collin V, Gilbert-Girard S, Morissette G, Kaufer BB, Flamand L. Characterization of human herpesvirus 6A/B U94 as ATPase, helicase, exonuclease and DNA-binding proteins. Nucleic Acids Res 2015; 43:6084-98. [PMID: 25999342 PMCID: PMC4499131 DOI: 10.1093/nar/gkv503] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/04/2015] [Indexed: 02/02/2023] Open
Abstract
Human herpesvirus-6A (HHV-6A) and HHV-6B integrate their genomes into the telomeres of human chromosomes, however, the mechanisms leading to integration remain unknown. HHV-6A/B encode a protein that has been proposed to be involved in integration termed U94, an ortholog of adeno-associated virus type 2 (AAV-2) Rep68 integrase. In this report, we addressed whether purified recombinant maltose-binding protein (MBP)-U94 fusion proteins of HHV-6A/B possess biological functions compatible with viral integration. We could demonstrate that MBP-U94 efficiently binds both dsDNA and ssDNA containing telomeric repeats using gel shift assay and surface plasmon resonance. MBP-U94 is also able to hydrolyze adenosine triphosphate (ATP) to ADP, providing the energy for further catalytic activities. In addition, U94 displays a 3′ to 5′ exonuclease activity on dsDNA with a preference for 3′-recessed ends. Once the DNA strand reaches 8–10 nt in length, the enzyme dissociates it from the complementary strand. Lastly, MBP-U94 compromises the integrity of a synthetic telomeric D-loop through exonuclease attack at the 3′ end of the invading strand. The preferential DNA binding of MBP-U94 to telomeric sequences, its ability to hydrolyze ATP and its exonuclease/helicase activities suggest that U94 possesses all functions required for HHV-6A/B chromosomal integration.
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Affiliation(s)
- Frédéric Trempe
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Annie Gravel
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Isabelle Dubuc
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Nina Wallaschek
- Institut für Virologie, Freie Universität Berlin, Berlin 14163, Germany
| | - Vanessa Collin
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Shella Gilbert-Girard
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Guillaume Morissette
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada
| | - Benedikt B Kaufer
- Institut für Virologie, Freie Universität Berlin, Berlin 14163, Germany
| | - Louis Flamand
- Division of Infectious Disease and Immunity, CHU de Québec Research Center, Quebec city, Quebec G1V 4G2, Canada Department of microbiology, infectious disease and immunology, Faculty of Medicine, Université Laval, Quebec city, Québec,G1V 0A6 Canada
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21
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Rizzo R, Zatelli MC, Rotola A, Cassai E, Degli Uberti E, Di Luca D, Caselli E. Increase in Peripheral CD3-CD56brightCD16- Natural Killer Cells in Hashimoto's Thyroiditis Associated with HHV-6 Infection. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 897:113-20. [PMID: 26566646 DOI: 10.1007/5584_2015_5010] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Hashimoto's thyroiditis (HT) is a very common autoimmune disease of the thyroid. In addition to genetic background, several viruses, including herpesviruses, have been suggested to play a role as possible environmental triggers of disease, but conclusive data are still lacking. Previous results showed that HT patients have an increased cellular immune response directed against the HHV-6 U94 protein and increased NK activity directed against HHV-6 infected thyrocytes.In this study, we characterized the antiviral antibody response and the NK cells activity and subtype in HHV-6 infected HT patients. The results showed that HT subjects have increased prevalence and titer of anti-U94 antibodies and a higher amount of CD3-CD56(bright)CD16(-)NK cell percentages compared to controls. Furthermore, the cell activation of CD3(-)CD56(bright) NK cells in HT patients significantly correlates with TPO and Tg Ab levels.The results suggest that HHV-6 might contribute to HT development, increasing NK cell secretion of inflammatory cytokines that could sustain the persistence of an inflammatory status in HT patients.
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Affiliation(s)
- Roberta Rizzo
- Department of Medical Sciences - Section of Microbiology and Medical Genetics, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy
| | - Maria Chiara Zatelli
- Section of Endocrinology and Internal Medicine, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Antonella Rotola
- Department of Medical Sciences - Section of Microbiology and Medical Genetics, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy
| | - Enzo Cassai
- Department of Medical Sciences - Section of Microbiology and Medical Genetics, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy
| | - Ettore Degli Uberti
- Section of Endocrinology and Internal Medicine, Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Dario Di Luca
- Department of Medical Sciences - Section of Microbiology and Medical Genetics, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy.
| | - Elisabetta Caselli
- Department of Medical Sciences - Section of Microbiology and Medical Genetics, University of Ferrara, Via Luigi Borsari, 46, 44121, Ferrara, Italy
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22
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Krug LT, Pellett PE. Roseolovirus molecular biology: recent advances. Curr Opin Virol 2014; 9:170-7. [PMID: 25437229 PMCID: PMC4753783 DOI: 10.1016/j.coviro.2014.10.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 10/16/2014] [Indexed: 12/29/2022]
Abstract
Human herpesviruses 6A, 6B, and 7 (HHV-6A, HHV-6B, and HHV-7) are classified within the roseolovirus genus of the betaherpesvirus subfamily. Most humans likely harbor at least two of these large DNA viruses, and 1% of humans harbor germline chromosomally integrated (ci) HHV-6A or HHV-6B genomes. Differences at the genetic level manifest as distinct biologic properties during infection and disease. We provide a brief synopsis of roseolovirus replication and highlight the unique properties of their lifecycle and what is known about the viral gene products that mediate these functions. In the nearly 30 years since their discovery, we have only begun to unlock the molecular strategies these highly evolved pathogens employ to establish and maintain chronic infections in humans.
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Affiliation(s)
- Laurie T Krug
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, NY 11794, United States
| | - Philip E Pellett
- Department of Immunology and Microbiology, Wayne State University, Detroit, MI 48201, United States.
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23
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Tweedy J, Spyrou MA, Hubacek P, Kuhl U, Lassner D, Gompels UA. Analyses of germline, chromosomally integrated human herpesvirus 6A and B genomes indicate emergent infection and new inflammatory mediators. J Gen Virol 2014; 96:370-389. [PMID: 25355130 DOI: 10.1099/vir.0.068536-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Human herpesvirus-6A (HHV-6A) is rarer than HHV-6B in many infant populations. However, they are similarly prevalent as germline, chromosomally integrated genomes (ciHHV-6A/B). This integrated form affects 0.1-1 % of the human population, where potentially virus gene expression could be in every cell, although virus relationships and health effects are not clear. In a Czech/German patient cohort ciHHV-6A was more common and diverse than ciHHV-6B. Quantitative PCR, nucleotide sequencing and telomeric integration site amplification characterized ciHHV-6 in 44 German myocarditis/cardiomyopathy and Czech malignancy/inflammatory disease (MI) patients plus donors. Comparisons were made to sequences from global virus reference strains, and blood DNA from childhood-infections from Zambia (HHV-6A mainly) and Japan (HHV-6B). The MI cohort were 86 % (18/21) ciHHV-6A, the cardiac cohort 65 % (13/20) ciHHV-6B, suggesting different disease links. Reactivation was supported by findings of 1) recombination between ciHHV-6A and HHV-6B genes in 20 % (4/21) of the MI cohort; 2) expression in a patient subset, of early/late transcripts from the inflammatory mediator genes chemokine receptor U51 and chemokine U83, both identical to ciHHV-6A DNA sequences; and 3) superinfection shown by deep sequencing identifying minor virus-variants only in ciHHV-6A, which expressed transcripts, indicating virus infection reactivates latent ciHHV-6A. Half the MI cohort had more than two copies per cell, median 5.2, indicative of reactivation. Remarkably, the integrated genomes encoded the secreted-active form of virus chemokines, rare in virus from childhood-infections. This shows integrated virus genomes can contribute new human genes with links to inflammatory pathology and supports ciHHV-6A reactivation as a source for emergent infection.
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Affiliation(s)
- J Tweedy
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, University of London, London, UK
| | - M A Spyrou
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, University of London, London, UK
| | - P Hubacek
- Department of Medical Microbiology and Department of Paediatric Haematology and Oncology, 2nd Medical Faculty of Charles University and Motol University Hospital, Prague, Czech Republic
| | - U Kuhl
- Department of Cardiology and Pneumology, Charité-University Medicine Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - D Lassner
- Institute of Cardiac Diagnostics and Therapy (IKDT), Berlin, Germany
| | - U A Gompels
- Pathogen Molecular Biology Department, London School of Hygiene and Tropical Medicine, University of London, London, UK
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24
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Kaufer BB, Flamand L. Chromosomally integrated HHV-6: impact on virus, cell and organismal biology. Curr Opin Virol 2014; 9:111-8. [PMID: 25462442 DOI: 10.1016/j.coviro.2014.09.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 09/24/2014] [Accepted: 09/25/2014] [Indexed: 11/16/2022]
Abstract
HHV-6 integrates its genome into telomeres of human chromosomes. Integration can occur in somatic cells or gametes, the latter leading to individuals harboring the HHV-6 genome in every cell. This condition is transmitted to descendants and referred to as inherited chromosomally integrated human herpesvirus 6 (iciHHV-6). Although integration can occur in different chromosomes, it invariably takes place in the telomere region. This integration mechanism represents a way to maintain the virus genome during latency, which is so far unique amongst human herpesviruses. Recent work provides evidence that the integrated HHV-6 genome can be mobilized from the host chromosome, resulting in the onset of disease. Details on required structural determinants, putative integration mechanisms and biological and medical consequences of iciHHV-6 are discussed.
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Affiliation(s)
| | - Louis Flamand
- Division of Infectious and Immune Diseases, CHU de Quebec, Research Center and Department of Microbiology-Infectious Diseases and Immunology, Université Laval, Quebec, Canada.
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25
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Zinn E, Vandenberghe LH. Adeno-associated virus: fit to serve. Curr Opin Virol 2014; 8:90-7. [PMID: 25128609 PMCID: PMC4195847 DOI: 10.1016/j.coviro.2014.07.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 07/21/2014] [Accepted: 07/24/2014] [Indexed: 12/20/2022]
Abstract
Adeno-associated virus (AAV) is a helper-dependent parvovirus which has not been linked with human disease. This aspect, in combination with its broad cell and tissue tropism, and limited viral host response has made it an attractive vector system for gene therapy. The viral protein capsid, the primary interface with the host, is the main determinant for these phenotypes, is highly variable, and is most subject to pressures during replication. Here, we explore the evolutionary path of AAV and other parvoviruses in respect to these phenotypes, as well as directed evolution and engineering strategies that have exploited the lessons learned from natural selection in order to address remaining limitations of AAV as a therapeutic gene transfer platform.
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Affiliation(s)
- Eric Zinn
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, United States
| | - Luk H Vandenberghe
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, United States.
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26
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Genomic organization and molecular characterization of porcine cytomegalovirus. Virology 2014; 460-461:165-72. [DOI: 10.1016/j.virol.2014.05.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 10/17/2013] [Accepted: 05/07/2014] [Indexed: 11/22/2022]
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27
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Osterrieder N, Wallaschek N, Kaufer BB. Herpesvirus Genome Integration into Telomeric Repeats of Host Cell Chromosomes. Annu Rev Virol 2014; 1:215-35. [PMID: 26958721 DOI: 10.1146/annurev-virology-031413-085422] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is well known that numerous viruses integrate their genetic material into host cell chromosomes. Human herpesvirus 6 (HHV-6) and oncogenic Marek's disease virus (MDV) have been shown to integrate their genomes into host telomeres of latently infected cells. This is unusual for herpesviruses as most maintain their genomes as circular episomes during the quiescent stage of infection. The genomic DNA of HHV-6, MDV, and several other herpesviruses harbors telomeric repeats (TMRs) that are identical to host telomere sequences (TTAGGG). At least in the case of MDV, viral TMRs facilitate integration into host telomeres. Integration of HHV-6 occurs not only in lymphocytes but also in the germline of some individuals, allowing vertical virus transmission. Although the molecular mechanism of telomere integration is poorly understood, the presence of TMRs in a number of herpesviruses suggests it is their default program for genome maintenance during latency and also allows efficient reactivation.
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Affiliation(s)
| | - Nina Wallaschek
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; ,
| | - Benedikt B Kaufer
- Institut für Virologie, Freie Universität Berlin, 14163 Berlin, Germany; ,
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Human herpesvirus 6A infection in CD46 transgenic mice: viral persistence in the brain and increased production of proinflammatory chemokines via Toll-like receptor 9. J Virol 2014; 88:5421-36. [PMID: 24574405 DOI: 10.1128/jvi.03763-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
UNLABELLED Human herpesvirus 6 (HHV-6) is widely spread in the human population and has been associated with several neuroinflammatory diseases, including multiple sclerosis. To develop a small-animal model of HHV-6 infection, we analyzed the susceptibility of several lines of transgenic mice expressing human CD46, identified as a receptor for HHV-6. We showed that HHV-6A (GS) infection results in the expression of viral transcripts in primary brain glial cultures from CD46-expressing mice, while HHV-6B (Z29) infection was inefficient. HHV-6A DNA persisted for up to 9 months in the brain of CD46-expressing mice but not in the nontransgenic littermates, whereas HHV-6B DNA levels decreased rapidly after infection in all mice. Persistence in the brain was observed with infectious but not heat-inactivated HHV-6A. Immunohistological studies revealed the presence of infiltrating lymphocytes in periventricular areas of the brain of HHV-6A-infected mice. Furthermore, HHV-6A stimulated the production of a panel of proinflammatory chemokines in primary brain glial cultures, including CCL2, CCL5, and CXCL10, and induced the expression of CCL5 in the brains of HHV-6A-infected mice. HHV-6A-induced production of chemokines in the primary glial cultures was dependent on the stimulation of toll-like receptor 9 (TLR9). Finally, HHV-6A induced signaling through human TLR9 as well, extending observations from the murine model to human infection. Altogether, this study presents a first murine model for HHV-6A-induced brain infection and suggests a role for TLR9 in the HHV-6A-initiated production of proinflammatory chemokines in the brain, opening novel perspectives for the study of virus-associated neuropathology. IMPORTANCE HHV-6 infection has been related to neuroinflammatory diseases; however, the lack of a suitable small-animal infection model has considerably hampered further studies of HHV-6-induced neuropathogenesis. In this study, we have characterized a new model for HHV-6 infection in mice expressing the human CD46 protein. Infection of CD46 transgenic mice with HHV-6A resulted in long-term persistence of viral DNA in the brains of infected animals and was followed by lymphocyte infiltration and upregulation of the CCL5 chemokine in the absence of clinical signs of disease. The secretion of a panel of chemokines was increased after infection in primary murine brain glial cultures, and the HHV-6-induced chemokine expression was inhibited when TLR9 signaling was blocked. These results describe the first murine model for HHV-6A-induced brain infection and suggest the importance of the TLR9 pathway in HHV-6A-initiated neuroinflammation.
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Prusty BK, Siegl C, Hauck P, Hain J, Korhonen SJ, Hiltunen-Back E, Puolakkainen M, Rudel T. Chlamydia trachomatis infection induces replication of latent HHV-6. PLoS One 2013; 8:e61400. [PMID: 23620749 PMCID: PMC3631192 DOI: 10.1371/journal.pone.0061400] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
Human herpesvirus-6 (HHV-6) exists in latent form either as a nuclear episome or integrated into human chromosomes in more than 90% of healthy individuals without causing clinical symptoms. Immunosuppression and stress conditions can reactivate HHV-6 replication, associated with clinical complications and even death. We have previously shown that co-infection of Chlamydia trachomatis and HHV-6 promotes chlamydial persistence and increases viral uptake in an in vitro cell culture model. Here we investigated C. trachomatis-induced HHV-6 activation in cell lines and fresh blood samples from patients having Chromosomally integrated HHV-6 (CiHHV-6). We observed activation of latent HHV-6 DNA replication in CiHHV-6 cell lines and fresh blood cells without formation of viral particles. Interestingly, we detected HHV-6 DNA in blood as well as cervical swabs from C. trachomatis-infected women. Low virus titers correlated with high C. trachomatis load and vice versa, demonstrating a potentially significant interaction of these pathogens in blood cells and in the cervix of infected patients. Our data suggest a thus far underestimated interference of HHV-6 and C. trachomatis with a likely impact on the disease outcome as consequence of co-infection.
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Affiliation(s)
- Bhupesh K. Prusty
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Christine Siegl
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Petra Hauck
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
| | - Johannes Hain
- Institute of Mathematics, Chair of Mathematics VIII (Statistics), University of Würzburg, Würzburg, Germany
| | - Suvi J. Korhonen
- Haartman Institute, Department of Virology, University of Helsinki, Helsinki, Finland
| | - Eija Hiltunen-Back
- Clinic of Venereal Diseases, Skin and Allergy Hospital, Helsinki University Central Hospital, Helsinki, Finland
- Department of Infectious Disease Surveillance and Control, National Institute of Health and Welfare, Helsinki, Finland
| | - Mirja Puolakkainen
- Haartman Institute, Department of Virology, University of Helsinki, Helsinki, Finland
- Helsinki University Central Hospital, Laboratory Division (HUSLAB), Department of Virology and Immunology, Helsinki, Finland
| | - Thomas Rudel
- Biocenter, Chair of Microbiology, University of Würzburg, Würzburg, Germany
- * E-mail:
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Caselli E, Zatelli MC, Rizzo R, Benedetti S, Martorelli D, Trasforini G, Cassai E, degli Uberti EC, Di Luca D, Dolcetti R. Virologic and immunologic evidence supporting an association between HHV-6 and Hashimoto's thyroiditis. PLoS Pathog 2012; 8:e1002951. [PMID: 23055929 PMCID: PMC3464215 DOI: 10.1371/journal.ppat.1002951] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/22/2012] [Indexed: 12/13/2022] Open
Abstract
Hashimoto's thyroiditis (HT) is the most common of all thyroid diseases and is characterized by abundant lymphocyte infiltrate and thyroid impairment, caused by various cell- and antibody-mediated immune processes. Viral infections have been suggested as possible environmental triggers, but conclusive data are not available. We analyzed the presence and transcriptional state of human herpesvirus 6 (HHV-6) in thyroid fine needle aspirates (FNA) and peripheral blood mononuclear cells (PBMCs) from 34 HT patients and 28 controls, showing that HHV-6 DNA prevalence (82% vs. 10%, p≤0.001) and viral load were significantly increased in FNA from HT patients, and thyrocytes from HT FNA displayed a 100-fold higher HHV-6 DNA load compared to infiltrating lymphocytes. In addition, while HHV-6 was strictly latent in positive samples from controls, a low grade acute infection was detected in HT samples. HHV-6 variant characterization was carried out in 10 HT FNA samples, determining that all specimens harbored HHV-6 Variant A. The tropism of HHV-6 for thyroid cells was verified by infection of Nthy-ori3-1, a thyroid follicular epithelial cell line, showing that thyrocytes are permissive to HHV-6 replication, which induces de novo expression of HLA class II antigens. Furthermore, HHV-6-infected Nthy-ori3-1 cells become targets for NK-mediated killing, NK cells from HT patients show a significantly more efficient killing of HHV-6 infected thyroid cells than healthy controls, and HT patients have increased T-cell responses to HHV-6 U94 protein, associated to viral latency. These observations suggest a potential role for HHV-6 (possibly variant A) in the development or triggering of HT. Hashimoto's thyroiditis (HT) is a very common autoimmune disease of the thyroid. In addition to genetic background, several viruses, including herpesviruses, have been suggested to play a role as possible environmental triggers of disease, but conclusive data are still lacking. The anecdotal presence of human herpesvirus 6 (HHV-6) in HT specimens prompted us to study a possible association between HHV-6 and HT. Our analysis of fine needle thyroid aspirates and blood from HT patients and controls shows that HHV-6 prevalence and load are highly increased in HT patients. Furthermore, HT-derived thyrocytes harbor active virus, whereas HHV-6 is strictly latent in the few virus-positive controls. We also report that HHV-6 infects thyroid cells, inducing de novo expression of HLA-II surface antigens. Consequently, thyrocytes might behave as antigen presenting cells. Interestingly, immune cells from HT patients kill HHV-6-infected thyrocytes more efficiently than controls. Also, HT patients, but not controls, have specific T-cell responses to HHV-6 U94 protein. It is difficult to prove etiologic links between viral infections and diseases, especially in the case of a ubiquitous agent such as HHV -6. Nevertheless, our findings indicate that HHV-6 might contribute to HT development, and argue for a pathogenic association between HHV-6 and HT.
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Affiliation(s)
- Elisabetta Caselli
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Ferrara, Italy.
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A novel bat herpesvirus encodes homologues of major histocompatibility complex classes I and II, C-type lectin, and a unique family of immune-related genes. J Virol 2012; 86:8014-30. [PMID: 22623774 DOI: 10.1128/jvi.00723-12] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Herpesviruses or herpesviral sequences have been identified in various bat species. Here, we report the isolation, cell tropism, and complete genome sequence of a novel betaherpesvirus from the bat Miniopterus schreibersii (MsHV). In primary cell culture, MsHV causes cytopathic effects (CPE) and reaches peak virus production 2 weeks after infection. MsHV was found to infect and replicate less efficiently in a feline kidney cell, CRFK, and failed to replicate in 13 other cell lines tested. Sequencing of the MsHV genome using the 454 system, with a 224-fold coverage, revealed a genome size of 222,870 bp. The genome was extensively analyzed in comparison to those of related viruses. Of the 190 predicted open reading frames (ORFs), 40 were identified as herpesvirus core genes. Among 93 proteins with identifiable homologues in tree shrew herpesvirus (THV), human cytomegalovirus (HCMV), or rat cytomegalovirus (RCMV), most had highest sequence identities with THV counterparts. However, the MsHV genome organization is colinear with that of RCMV rather than that of THV. The following unique features were discovered in the MsHV genome. One predicted protein, B125, is similar to human herpesvirus 6 (HHV-6) U94, a homologue of the parvovirus Rep protein. For the unique ORFs, 7 are predicted to encode major histocompatibility complex (MHC)-related proteins, 2 to encode MHC class I homologues, and 3 to encode MHC class II homologues; 4 encode the homologues of C-type lectin- or natural killer cell lectin-like receptors;, and the products of a unique gene family, the b149 family, of 16 members, have no significant sequence identity with known proteins but exhibit immunoglobulin-like beta-sandwich domains revealed by three-dimensional (3D) structural prediction. To our knowledge, MsHV is the first virus genome known to encode MHC class II homologues.
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Arbuckle JH, Medveczky PG. The molecular biology of human herpesvirus-6 latency and telomere integration. Microbes Infect 2011; 13:731-41. [PMID: 21458587 DOI: 10.1016/j.micinf.2011.03.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 03/23/2011] [Indexed: 01/09/2023]
Abstract
The genomes of herpesviruses establish latency as a circular episome. However, Human herpesvirus-6 (HHV-6) has been shown to specifically integrate into the telomeres of chromosomes during latency and vertically transmit through the germ-line. This review will focus on the telomere integration of HHV-6, the potential viral and cellular genes that mediate integration, and the clinical impact on the host.
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Affiliation(s)
- Jesse H Arbuckle
- Department of Molecular Medicine, University of South Florida College of Medicine, 12901 Bruce B Downs Blvd, Tampa, FL 33612, USA
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Abstract
Herpesviruses are members of a diverse family of viruses that colonize all vertebrates from fish to mammals. Although more than one hundred herpesviruses exist, all are nearly identical architecturally, with a genome consisting of a linear double-stranded DNA molecule (100 to 225 kbp) protected by an icosahedral capsid made up of 162 hollow-centered capsomeres, a tegument surrounding the nucleocapsid, and a viral envelope derived from host membranes. Upon infection, the linear viral DNA is delivered to the nucleus, where it circularizes to form the viral episome. Depending on several factors, the viral cycle can proceed either to a productive infection or to a state of latency. In either case, the viral genetic information is maintained as extrachromosomal circular DNA. Interestingly, however, certain oncogenic herpesviruses such as Marek's disease virus and Epstein-Barr virus can be found integrated at low frequencies in the host's chromosomes. These findings have mostly been viewed as anecdotal and considered exceptions rather than properties of herpesviruses. In recent years, the consistent and rather frequent detection (in approximately 1% of the human population) of human herpesvirus 6 (HHV-6) viral DNA integrated into human chromosomes has spurred renewed interest in our understanding of how these viruses infect, replicate, and propagate themselves. In this review, we provide a historical perspective on chromosomal integration by herpesviruses and present the current state of knowledge on integration by HHV-6 with the possible clinical implications associated with viral integration.
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U94 of human herpesvirus 6 inhibits in vitro angiogenesis and lymphangiogenesis. Proc Natl Acad Sci U S A 2009; 106:20446-51. [PMID: 19918067 DOI: 10.1073/pnas.0905535106] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) is a lymphotropic virus, but recent observations showed that also vascular endothelial cells (ECs) are susceptible to infection, both in vivo and in vitro. The observation that lymph nodes are a site of viral persistence suggests that lymphatic ECs (LECs) might be even more relevant for HHV-6 biology than vascular ECs. Here, we provide evidence that HHV-6 can infect LECs in vitro and establish a latent infection. Thus HHV-6 infection induces the loss of angiogenic properties both in LECs and in vascular ECs, as shown by the inability to form capillary-like structures and to seal wound scratches. The antiangiogenic effects observed in infected cells are associated to the expression of HHV-6 U94/rep, a latency-associated gene. In fact, transfection of U94/rep or addition of recombinant U94/REP protein to ECs inhibits the formation of in vitro capillary-like structures, reduces migration of ECs, and blocks angiogenesis, rendering rat aortic rings insensitive to VEGF-induced vasculogenetic activity. The ability of U94/rep to block different angiogenetic steps may lead to approaches in the potential control of the proliferation of blood and lymphatic vessels.
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Caselli E, Galvan M, Santoni F, Alvarez S, de Lera AR, Ivanova D, Gronemeyer H, Caruso A, Guidoboni M, Cassai E, Dolcetti R, Di Luca D. Retinoic Acid Analogues Inhibit Human Herpesvirus 8 Replication. Antivir Ther 2008. [DOI: 10.1177/135965350801300205] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Retinoids have a pronounced antiviral effect against several viruses. In this study we aimed to investigate the effect of retinoids on human herpesvirus 8 (HHV-8). Methods A panel of retinoic acid compounds were tested for their antiviral activity against HHV-8 in human umbilical vascular endothelial cells (HUVECs) and in a human epithelial cell line. The presence, transcription and antigen expression of HHV-8 in infected cells – in the presence or absence of retinoic acid compounds – were evaluated by PCR, reverse transcriptase PCR and immunofluorescence assays; HHV-8 viral load was determined by real-time quantitative PCR. Angiogenesis induced by HHV-8 was also assessed using Cultrex® basement membrane extract. Results The compounds tested specifically inhibited viral promoters, during the early and late phases of infection in both cell systems tested, and resulted in up to 100fold reduction of viral titre and release of progeny virus. The inhibition of viral replication induced by retinoids in endothelial cells, the primary target of HHV-8-driven transformation in Kaposi's Sarcoma, prevented endothelial cells from developing spindle morphology and in vitro tube formation, characteristic changes associated with HHV-8 infection and transformation. Conclusions We show that retinoids inhibit HHV-8 replication and identify new retinoid compounds with a strong antiviral effect. Selective retinoids, particularly those with retinoic acid receptor agonist activity, may be good candidates for the development of antiviral drugs.
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Affiliation(s)
- Elisabetta Caselli
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
| | - Monica Galvan
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
| | - Fabio Santoni
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
| | - Susana Alvarez
- Departamento de Química Orgànica, Universidade de Vigo, Spain
| | - Angel R de Lera
- Departamento de Química Orgànica, Universidade de Vigo, Spain
| | - Diana Ivanova
- Departamento de Química Orgànica, Universidade de Vigo, Spain
- Department of Cancer Biology, IGBMC, Strasbourg, France
| | | | - Arnaldo Caruso
- Section of Microbiology, Department of Experimental and Applied Medicine, University of Brescia, Italy
| | - Massimo Guidoboni
- Immunovirology and Biotherapy Unit, CRO – IRCCS, National Cancer Institute, Aviano, Italy
- Present address: Division of Medical Oncology and Immunotherapy, Department of Oncology, University Hospital of Siena, Istituto Toscano Tumori, Siena, Italy
| | - Enzo Cassai
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
| | - Riccardo Dolcetti
- Immunovirology and Biotherapy Unit, CRO – IRCCS, National Cancer Institute, Aviano, Italy
| | - Dario Di Luca
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
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Goodrum F, Reeves M, Sinclair J, High K, Shenk T. Human cytomegalovirus sequences expressed in latently infected individuals promote a latent infection in vitro. Blood 2007; 110:937-45. [PMID: 17440050 PMCID: PMC1924770 DOI: 10.1182/blood-2007-01-070078] [Citation(s) in RCA: 193] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Accepted: 04/05/2007] [Indexed: 01/20/2023] Open
Abstract
Latency enables human cytomegalovirus (HCMV) to persist in the hematopoietic cells of infected individuals indefinitely and prevents clearance of the pathogen. Despite its critical importance to the viral infectious cycle, viral mechanisms that contribute to latency have not been identified. We compared the ability of low-passage clinical and laboratory-adapted strains of HCMV to establish a latent infection in primary human CD34(+) cells. The low-passage strains, Toledo and FIX, established an infection with the hallmarks of latency, whereas the laboratory strains, AD169 and Towne, replicated producing progeny virus. We hypothesized that ULb' region of the genome, which is unique to low-passage strains, may encode a latency-promoting activity. We created and analyzed recombinant viruses lacking segments or individual open reading frames (ORFs) in the ULb' region. One 5-kb segment, and more specifically the UL138 ORF, was required for HCMV to establish and/or maintain a latent infection in hematopoietic progenitor cells infected in vitro. This is the first functional demonstration of a virus-coded sequence required for HCMV latency. Importantly, UL138 RNA was expressed in CD34(+) cells and monocytes from HCMV-seropositive, healthy individuals. UL138 might be a target for antivirals against latent virus.
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Affiliation(s)
- Felicia Goodrum
- Department of Immunobiology, BIO5 Institute, University of Arizona, Tucson, AZ 85711, USA.
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Abstract
Since its isolation more than 20 years ago, human herpesvirus (HHV)-6 has been considered an opportunistic pathogen whose infection and/or reactivation is associated with diseases such as roseola, organ transplant anomalies and central nervous system disorders. The lack of relevant animal models, standardized diagnostic reagents and specific anti-HHV-6 drugs has impaired our ability to prove a causal relationship between the presence of this virus and the development of many diseases. Unless such models and reagents are developed and clinical trials performed, speculations on the role for this virus in various pathologies will continue to grow. In this review, recent biological, clinical and epidemiological research advances in the HHV-6 field as well as that of its closest relative, HHV-7, will be presented. Additionally, priority research areas that will help move the field forward are discussed.
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Affiliation(s)
- Andru Tomoiu
- Laboratory of Virology, Rheumatology & Immunology Research Center, CHUQ Research Center & Faculty of Medicine, Laval University, Quebec, Canada
| | - Louis Flamand
- Laboratory of Virology, Rheumatology & Immunology Research Center, CHUQ Research Center & Faculty of Medicine, Laval University, Quebec, Canada
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