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Komaroff AL, Pellett PE, Jacobson S. Human Herpesviruses 6A and 6B in Brain Diseases: Association versus Causation. Clin Microbiol Rev 2020; 34:e00143-20. [PMID: 33177186 PMCID: PMC7667666 DOI: 10.1128/cmr.00143-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Human herpesvirus 6A (HHV-6A) and human herpesvirus 6B (HHV-6B), collectively termed HHV-6A/B, are neurotropic viruses that permanently infect most humans from an early age. Although most people infected with these viruses appear to suffer no ill effects, the viruses are a well-established cause of encephalitis in immunocompromised patients. In this review, we summarize the evidence that the viruses may also be one trigger for febrile seizures (including febrile status epilepticus) in immunocompetent infants and children, mesial temporal lobe epilepsy, multiple sclerosis (MS), and, possibly, Alzheimer's disease. We propose criteria for linking ubiquitous infectious agents capable of producing lifelong infection to any neurologic disease, and then we examine to what extent these criteria have been met for these viruses and these diseases.
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Affiliation(s)
- Anthony L Komaroff
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Philip E Pellett
- Department of Microbiology and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Steven Jacobson
- Virology/Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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2
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Amini R, Karampoor S, Zahednasab H, Keyvani H, Gheiasian M, Jalilian FA. Serum levels of matrix metalloproteinase-2, -9, and vitamin D in patients with multiple sclerosis with or without herpesvirus-6 seropositivity. Braz J Infect Dis 2020; 24:144-149. [PMID: 32243867 PMCID: PMC9392051 DOI: 10.1016/j.bjid.2020.02.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 02/10/2020] [Accepted: 02/24/2020] [Indexed: 12/17/2022] Open
Affiliation(s)
- Razieh Amini
- Hamadan University of Medical Sciences, Faculty of Medicine, Department of Molecular Medicine and Genetics, Hamadan, Iran
| | - Sajad Karampoor
- Iran University of Medical Sciences, School of Medicine, Department of Virology, Tehran, Iran.
| | - Hamid Zahednasab
- University of Tehran, Institute of Biochemistry and Biophysics, Tehran, Iran
| | - Hossein Keyvani
- Iran University of Medical Sciences, School of Medicine, Department of Virology, Tehran, Iran
| | - Masoud Gheiasian
- Hamadan University of Medical Sciences, Faculty of Medicine, Department of Neurology, Hamadan, Iran
| | - Farid Azizi Jalilian
- Hamadan University of Medical Sciences, Faculty of Medicine Hamadan, Department of Medical Virology, Hamadan, Iran.
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3
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Engdahl E, Gustafsson R, Huang J, Biström M, Lima Bomfim I, Stridh P, Khademi M, Brenner N, Butt J, Michel A, Jons D, Hortlund M, Alonso-Magdalena L, Hedström AK, Flamand L, Ihira M, Yoshikawa T, Andersen O, Hillert J, Alfredsson L, Waterboer T, Sundström P, Olsson T, Kockum I, Fogdell-Hahn A. Increased Serological Response Against Human Herpesvirus 6A Is Associated With Risk for Multiple Sclerosis. Front Immunol 2019; 10:2715. [PMID: 32038605 PMCID: PMC6988796 DOI: 10.3389/fimmu.2019.02715] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 11/05/2019] [Indexed: 11/26/2022] Open
Abstract
Human herpesvirus (HHV)-6A or HHV-6B involvement in multiple sclerosis (MS) etiology has remained controversial mainly due to the lack of serological methods that can distinguish the two viruses. A novel multiplex serological assay measuring IgG reactivity against the immediate-early protein 1 from HHV-6A (IE1A) and HHV-6B (IE1B) was used in a MS cohort (8,742 persons with MS and 7,215 matched controls), and a pre-MS cohort (478 individuals and 476 matched controls) to investigate this further. The IgG response against IE1A was positively associated with MS (OR = 1.55, p = 9 × 10-22), and increased risk of future MS (OR = 2.22, p = 2 × 10-5). An interaction was observed between IE1A and Epstein-Barr virus (EBV) antibody responses for MS risk (attributable proportion = 0.24, p = 6 × 10-6). In contrast, the IgG response against IE1B was negatively associated with MS (OR = 0.74, p = 6 × 10-11). The association did not differ between MS subtypes or vary with severity of disease. The genetic control of HHV-6A/B antibody responses were located to the Human Leukocyte Antigen (HLA) region and the strongest association for IE1A was the DRB1*13:01-DQA1*01:03-DQB1*06:03 haplotype while the main association for IE1B was DRB1*13:02-DQA1*01:02-DQB1*06:04. In conclusion a role for HHV-6A in MS etiology is supported by an increased serological response against HHV-6A IE1 protein, an interaction with EBV, and an association to HLA genes.
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Affiliation(s)
- Elin Engdahl
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Rasmus Gustafsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Jesse Huang
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Martin Biström
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Izaura Lima Bomfim
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Pernilla Stridh
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Mohsen Khademi
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Nicole Brenner
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Julia Butt
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Angelika Michel
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Daniel Jons
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Maria Hortlund
- Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Anna Karin Hedström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Louis Flamand
- Department of Microbiology, Infectious Disease and Immunology, Laval University, Quebec City, QC, Canada
| | - Masaru Ihira
- Clinical Engineering Technology, Fujita Health University School of Medical Sciences, Toyoake, Japan
| | - Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Japan
| | - Oluf Andersen
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Jan Hillert
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Lars Alfredsson
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden
| | - Tim Waterboer
- Infections and Cancer Epidemiology, German Cancer Research Center (Deutsches Krebsforschungszentrum), Heidelberg, Germany
| | - Peter Sundström
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - Tomas Olsson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Ingrid Kockum
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
| | - Anna Fogdell-Hahn
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Stockholm, Sweden
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Reiss CS. Virus-Induced Demyelination: The Case for Virus(es) in Multiple Sclerosis. NEUROTROPIC VIRAL INFECTIONS 2016. [PMCID: PMC7122906 DOI: 10.1007/978-3-319-33189-8_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Multiple Sclerosis (MS) is the most common demyelinating disease of man with over 400,000 cases in the United States and over 2.5 million cases worldwide. There are over 64,000 citations in Pubmed dating back as far as 1887. Much has been learned over the past 129 years with a recent burst in therapeutic options (mostly anti-inflammatory) with newer medications in development that are neuroprotective and/or neuroreparative. However, with all these advancements the cause of MS remains elusive. There is a clear interplay of genetic, immunologic, and environmental factors that influences both the development and progression of this disorder. This chapter will give a brief overview of the history and pathogenesis of MS with attention to how host immune responses in genetically susceptible individuals contribute to the MS disease process. In addition, we will explore the role of infectious agents in MS as potential “triggers” of disease. Models of virus-induced demyelination will be discussed, with an emphasis on the recent interest in human herpesviruses and the role they may play in MS disease pathogenesis. Although we remain circumspect as to the role of any microbial pathogen in MS, we suggest that only through well-controlled serological, cellular immune, molecular, and animal studies we will be able to identify candidate agents. Ultimately, clinical interventional trials that either target a specific pathogen or class of pathogens will be required to make definitive links between the suspected agent and MS.
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Affiliation(s)
- Carol Shoshkes Reiss
- Departments of Biology and Neural Science, New York University, New York, New York USA
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Hon GM, Erasmus RT, Matsha TE. Mini review article. Human herpesvirus-6 and the etiology of multiple sclerosis: a literature review. ASIAN BIOMED 2014. [DOI: 10.5372/1905-7415.0803.294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Abstract
Background: There is no consensus in the literature on the role of human herpes virus-6 (HHV-6) in multiple sclerosis (MS) onset or progression.
Objective: We evaluated a possible role for HHV-6 in MS onset and progression.
Methods: We conducted a literature search of PubMed and Google scholar with the following search terms: (“multiple sclerosis” OR “MS”) and (“Human Herpes Virus-6” OR “HHV-6”).
Results: A total 21 publications were retrieved, of which 19 case-control studies were included. A further 25 articles were retrieved for background information.
Conclusion: There was insufficient evidence to support a role of HHV-6 in MS onset and progression.
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Affiliation(s)
- Gloudina M. Hon
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, Bellville 7530, South Africa
| | - Rajiv T. Erasmus
- Division of Chemical Pathology, University of Stellenbosch, Tygerberg 7505, South Africa
| | - Tandi E. Matsha
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, Bellville 7530, South Africa
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6
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Engdahl E, Gustafsson R, Ramanujam R, Sundqvist E, Olsson T, Hillert J, Alfredsson L, Kockum I, Fogdell-Hahn A. HLA-A∗02, gender and tobacco smoking, but not multiple sclerosis, affects the IgG antibody response against human herpesvirus 6. Hum Immunol 2014; 75:524-30. [DOI: 10.1016/j.humimm.2014.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 12/03/2013] [Accepted: 03/11/2014] [Indexed: 01/16/2023]
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Hon GM, Erasmus RT, Matsha T. Low prevalence of human herpesvirus-6 and varicella zoster virus in blood of multiple sclerosis patients, irrespective of inflammatory status or disease progression. J Clin Neurosci 2014; 21:1437-40. [PMID: 24534629 DOI: 10.1016/j.jocn.2013.10.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/25/2013] [Accepted: 10/21/2013] [Indexed: 10/25/2022]
Abstract
Herpesviruses, including human herpesvirus-6 and varicella zoster virus, have been implicated in the disease aetiology of multiple sclerosis. These viruses are capable of reactivation, reminiscent of the relapsing-remitting nature of multiple sclerosis. However, viral DNA has also been reported present in healthy controls, often at similar prevalence rates. This study aimed to determine whether prevalence could be associated with different stages of activity of the disease as well as the inflammatory status of the patients. Polymerase chain reaction assays were used to screen for human herpesvirus-6 and varicella zoster virus DNA in blood from 31 Caucasian patients with multiple sclerosis and 30 healthy age, sex and race matched control subjects. The patients were screened for inflammation using C-reactive protein as a marker and were also categorized according to their remitting/relapsing status. Results were positive for human herpesvirus-6 in blood from only one patient (3.2%) and human herpesvirus-6 DNA was not present in any control subjects. Varicella zoster virus was not detected in either the patients or control subjects. Similar to some other studies we saw an absence or very low viral positivity in blood from both patients and controls. These findings were irrespective of relapse episodes, increased inflammatory status or duration of the disease. Results therefore do not support a causative role for either human herpesvirus-6 or varicella zoster virus in the disease aetiology of multiple sclerosis, but rather that prevalence in patients may be linked to that of the general population.
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Affiliation(s)
- Gloudina M Hon
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7530, Cape Town, South Africa.
| | - Rajiv T Erasmus
- Division of Chemical Pathology, University of Stellenbosch, Tygerberg Campus, Tygerberg, South Africa
| | - Tandi Matsha
- Department of Bio-Medical Sciences, Faculty of Health and Wellness Science, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7530, Cape Town, South Africa
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8
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Affiliation(s)
- Joshua A Hill
- Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA.
| | - Nagagopal Venna
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
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9
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HHV-6 and Multiple Sclerosis. HUMAN HERPESVIRUSES HHV-6A, HHV-6B & HHV-7 2014. [PMCID: PMC7152315 DOI: 10.1016/b978-0-444-62703-2.00007-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease affecting the central nervous system, thought to be an autoimmune disease mediated by autoreactive lymphocytes. The pathogenesis of MS is multifactorial and is thought to be triggered by multiple environmental factors in genetically susceptible individuals. Viruses have long been postulated as potential environmental triggers in MS, and there is increasing evidence of a link between viruses and MS. Some of the most compelling data have been found in human herpesvirus 6 (HHV-6) research. HHV-6 is a ubiquitous, neurotropic herpesvirus; HHV-6 DNA has been found in MS plaques compared to healthy brain tissue. Studies have also shown that MS patients have higher viral titers and higher DNA detection in serum and CSF compared to controls, and that the virus seems to be more actively replicating in MS patients. Potential mechanisms for HHV-6 leading to autoimmunity include molecular mimicry, bystander activation, and epitope spreading, among others.
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Virtanen JO, Jacobson S. Viruses and multiple sclerosis. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2012; 11:528-44. [PMID: 22583435 DOI: 10.2174/187152712801661220] [Citation(s) in RCA: 116] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 04/13/2012] [Accepted: 04/20/2012] [Indexed: 11/22/2022]
Abstract
Multiple sclerosis (MS) is a heterogeneous disease that develops as an interplay between the immune system and environmental stimuli in genetically susceptible individuals. There is increasing evidence that viruses may play a role in MS pathogenesis acting as these environmental triggers. However, it is not known if any single virus is causal, or rather several viruses can act as triggers in disease development. Here, we review the association of different viruses to MS with an emphasis on two herpesviruses, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6). These two agents have generated the most impact during recent years as possible co-factors in MS disease development. The strongest argument for association of EBV with MS comes from the link between symptomatic infectious mononucleosis and MS and from seroepidemiological studies. In contrast to EBV, HHV-6 has been found significantly more often in MS plaques than in MS normal appearing white matter or non-MS brains and HHV-6 re-activation has been reported during MS clinical relapses. In this review we also suggest new strategies, including the development of new infectious animal models of MS and antiviral MS clinical trials, to elucidate roles of different viruses in the pathogenesis of this disease. Furthermore, we introduce the idea of using unbiased sequence-independent pathogen discovery methodologies, such as next generation sequencing, to study MS brain tissue or body fluids for detection of known viral sequences or potential novel viral agents.
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Affiliation(s)
- Jussi Oskari Virtanen
- Viral Immunology Section, Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Hwang T, Atluri G, Xie M, Dey S, Hong C, Kumar V, Kuang R. Co-clustering phenome-genome for phenotype classification and disease gene discovery. Nucleic Acids Res 2012; 40:e146. [PMID: 22735708 PMCID: PMC3479160 DOI: 10.1093/nar/gks615] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Understanding the categorization of human diseases is critical for reliably identifying disease causal genes. Recently, genome-wide studies of abnormal chromosomal locations related to diseases have mapped >2000 phenotype–gene relations, which provide valuable information for classifying diseases and identifying candidate genes as drug targets. In this article, a regularized non-negative matrix tri-factorization (R-NMTF) algorithm is introduced to co-cluster phenotypes and genes, and simultaneously detect associations between the detected phenotype clusters and gene clusters. The R-NMTF algorithm factorizes the phenotype–gene association matrix under the prior knowledge from phenotype similarity network and protein–protein interaction network, supervised by the label information from known disease classes and biological pathways. In the experiments on disease phenotype–gene associations in OMIM and KEGG disease pathways, R-NMTF significantly improved the classification of disease phenotypes and disease pathway genes compared with support vector machines and Label Propagation in cross-validation on the annotated phenotypes and genes. The newly predicted phenotypes in each disease class are highly consistent with human phenotype ontology annotations. The roles of the new member genes in the disease pathways are examined and validated in the protein–protein interaction subnetworks. Extensive literature review also confirmed many new members of the disease classes and pathways as well as the predicted associations between disease phenotype classes and pathways.
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Affiliation(s)
- TaeHyun Hwang
- Bioinformatics core at Masonic Cancer Center, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA
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Voumvourakis KI, Kitsos DK, Tsiodras S, Petrikkos G, Stamboulis E. Human herpesvirus 6 infection as a trigger of multiple sclerosis. Mayo Clin Proc 2010; 85:1023-30. [PMID: 20926836 PMCID: PMC2966366 DOI: 10.4065/mcp.2010.0350] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We systematically reviewed the existing evidence to determine whether a relationship exists between infection with human herpesvirus 6 (HHV-6) and multiple sclerosis (MS) and, if so, to define the strength of that relationship. The following terms were used in searches of the Entrez-PubMed database (1966-2009): human herpes virus 6, HHV 6, demyelination, multiple sclerosis, pathogenesis, diagnosis, serology, cerebrospinal fluid, IgG antibodies, IgM antibodies, PCR, and lymphoproliferative techniques. Study quality was assessed using the criteria proposed by Moore and Wolfson and by the classification criteria used by the Canadian Task Force on the Periodic Health Examination. Studies were categorized both by experimental technique and by quality (high [A], intermediate [B], and low [C]) as determined by the Moore and Wolfson criteria. Overall, 25 (41%) of 61 studies, 15 (60%) of which were classified as A quality, reached a statistically significant result. According to the Canadian Task Force classification, all studies were categorized as evidence of quality II-1. Limitations of the available experimental techniques and perspectives for future research are discussed. The current review supports the need for further, objective, evidence-based examination of the relationship between HHV-6 infection and multiple sclerosis.
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Affiliation(s)
- Konstantine I Voumvourakis
- 2nd Department of Neurology, Attikon University Hospital, University of Athens Medical School, Athens, Greece.
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13
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Lipid autoreactivity in multiple sclerosis. Med Hypotheses 2009; 74:433-42. [PMID: 19932569 DOI: 10.1016/j.mehy.2009.10.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2009] [Accepted: 10/08/2009] [Indexed: 01/20/2023]
Abstract
Lipids comprise over 70% of the myelin sheath but have been largely underinvestigated as autoantigens in multiple sclerosis (MS). This paper cites evidence for the involvement of lipid autoreactivity in MS and details how self lipid cross-reactivity may also contribute to the development of type 1 diabetes and autoimmune thyroid disorders (both of which have been associated with MS). A further analysis of myelin chemistry suggests several mechanisms by which infection may contribute to etiology and trigger lipid autoreactivity via molecular mimicry. This analysis may aid the development of new therapies for autoimmune diseases.
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Kuusisto H, Hyöty H, Kares S, Kinnunen E, Elovaara I. Human herpes virus 6 and multiple sclerosis: a Finnish twin study. Mult Scler 2007; 14:54-8. [PMID: 17893113 DOI: 10.1177/1352458507080063] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To investigate the possible association of human herpes virus 6- (HHV6) infection and multiple sclerosis (MS). BACKGROUND Despite intensive investigations of genetic and environmental factors, the etiopathogenesis of MS remains unknown. HHV6 is a possible candidate in that it is neurotropic, able to induce demyelination and become latent and be reactivated. We had access to The Finnish National Twin Cohort, which provided a unique opportunity to study the association between HHV6 and MS in genetically homogenous patients. METHODS Thirty-four serum samples from 17 MS twin pairs and 12 cerebrospinal fluid (CSF) samples from six MS twin pairs were tested by PCR specific for HHV6. Immunoglobulin (Ig) G and M response against HHV6 in serum and CSF were analysed using ELISA method. The samples were collected during a remission of the disease. RESULTS No HHV6 DNA was found in any serum (n=34) or CSF (n=12) samples. Eighty-eight percent of the twins with MS and 86% of the healthy twin siblings were positive for IgG in serum. One twin with MS was also positive for IgM in serum, whereas none of the healthy twins was IgM positive. All CSF samples were negative for IgG and IgM in both groups. CONCLUSIONS During a clinical remission of MS the detection of antibodies against HHV6 in CSF and HHV6 DNA in serum, CSF supernatant or CSF leukocytes is unlikely. However, the results do not exclude a possibility of HHV6 reactivation during MS exacerbation or acute HHV6 infection being one of the triggering agents in development of MS long before its clinical manifestation.
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Affiliation(s)
- H Kuusisto
- Department of Neurology, University Hospital of Tampere, Tampere, Finland.
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15
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Meeuwsen S, Persoon-Deen C, Bsibsi M, Bajramovic JJ, Ravid R, De Bolle L, van Noort JM. Modulation of the cytokine network in human adult astrocytes by human herpesvirus-6A. J Neuroimmunol 2005; 164:37-47. [PMID: 15904975 DOI: 10.1016/j.jneuroim.2005.03.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Revised: 03/16/2005] [Accepted: 03/16/2005] [Indexed: 11/27/2022]
Abstract
Human herpesvirus-6A (HHV-6A) is a common pathogen whose role in CNS disorders including multiple sclerosis remains controversial. To understand how HHV-6A could influence inflammatory pathways in the CNS, we infected cultured human adult astrocytes and examined the expression of 268 cytokines, chemokines, growth factors and their receptors by gene profiling. HHV-6 infection alone had little effect on the astrocyte gene profile but strongly altered the astrocyte response to proinflammatory cytokines. Under those conditions astrocytes express higher levels of anti-inflammatory mediators including IL-10 and IL-11, chemotactic factors, growth factors and factors controlling type I interferon production. Our data suggest that HHV-6 itself does not evoke a pro-inflammatory response in astrocytes but rather triggers immune modulatory factors in the face of inflammation.
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Affiliation(s)
- Sonja Meeuwsen
- Division Biomedical Research, TNO Prevention and Health, P.O. Box 2215, 2301 CE Leiden, The Netherlands
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Friedman JE, Zabriskie JB, Plank C, Ablashi D, Whitman J, Shahan B, Edgell R, Shieh M, Rapalino O, Zimmerman R, Sheng D. A randomized clinical trial of valacyclovir in multiple sclerosis. Mult Scler 2005; 11:286-95. [PMID: 15957509 DOI: 10.1191/1352458505ms1185oa] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVE The human Herpesvirus type-6 (HHV-6) has been implicated in multiple sclerosis (MS). Valacyclovir is an antiviral agent with an excellent safety profile. A two-year placebo-controlled, double-blind study was conducted to (1) ascertain if high-dose, prolonged treatment with valacyclovir would be safe and (2) observe if valacyclovir would delay the progression of MS clinically or by magnetic resonance imaging (MRI). DESIGN/METHODS Fifty-eight patients were stratified as to severity and randomly assigned to receive valacyclovir (3000 mg/day) or placebo for a period of two years. Patients were followed clinically over the two-year period by means of the Expanded Disability Status Scale (EDSS), the Ambulation Index (AI) and brain MRI scans. Patients underwent routine lab studies every three months. Patients continued on the medication for two years unless they had a sustained progression or repeated exacerbations. RESULTS No patient discontinued the study due to side effects or toxicity. In Relative Ranking of Progression, time to first attack, attack rate, and time to withdrawal there were trends (but not statistically significant) toward drug effect over placebo in the Severe clinical category. MRI evaluation showed no significant drug effect. CONCLUSIONS Although not statistically significant, positive trends were detected for acyclovir by clinical measures, but not by MRI.
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Affiliation(s)
- J E Friedman
- Department of Neurology, New York University School of Medicine, NY, NY 10010, USA.
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Rotola A, Merlotti I, Caniatti L, Caselli E, Granieri E, Tola MR, Di Luca D, Cassai E. Human herpesvirus 6 infects the central nervous system of multiple sclerosis patients in the early stages of the disease. Mult Scler 2005; 10:348-54. [PMID: 15327028 DOI: 10.1191/1352458504ms1045oa] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The presence and the replicative state of human herpesvirus 6 (HHV-6) were evaluated in clinical samples from multiple sclerosis (MS) patients at the first time of MS diagnosis. HHV-6 variant B was present in peripheral blood mononuclear cells of 5/32 (15%) patients, but persisted with a latent infection. Viral sequences were present also in cerebrospinal fluid (CSF), both free in the liquid (7/32, 22%) and latent in the cellular fraction (3/32, 9%), as shown by analysis of viral transcription. In these cases, variant A was detected. HHV-6 DNA sequences present in the CSF were associated to mature viral particles. In fact, in vitro infectious assays of CSF showed the presence of replication-competent virions. These results show that about 20% of MS patients have active foci of HHV-6 variant A infection in the early stages of the disease and suggest that viral replication takes place within the central nervous system.
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Affiliation(s)
- A Rotola
- Section of Microbiology, Department of Experimental and Diagnostic Medicine, University of Ferrara, Italy
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18
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De Bolle L, Naesens L, De Clercq E. Update on human herpesvirus 6 biology, clinical features, and therapy. Clin Microbiol Rev 2005; 18:217-45. [PMID: 15653828 PMCID: PMC544175 DOI: 10.1128/cmr.18.1.217-245.2005] [Citation(s) in RCA: 341] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) is a betaherpesvirus that is closely related to human cytomegalovirus. It was discovered in 1986, and HHV-6 literature has expanded considerably in the past 10 years. We here present an up-to-date and complete overview of the recent developments concerning HHV-6 biological features, clinical associations, and therapeutic approaches. HHV-6 gene expression regulation and gene products have been systematically characterized, and the multiple interactions between HHV-6 and the host immune system have been explored. Moreover, the discovery of the cellular receptor for HHV-6, CD46, has shed a new light on HHV-6 cell tropism. Furthermore, the in vitro interactions between HHV-6 and other viruses, particularly human immunodeficiency virus, and their relevance for the in vivo situation are discussed, as well as the transactivating capacities of several HHV-6 proteins. The insight into the clinical spectrum of HHV-6 is still evolving and, apart from being recognized as a major pathogen in transplant recipients (as exemplified by the rising number of prospective clinical studies), its role in central nervous system disease has become increasingly apparent. Finally, we present an overview of therapeutic options for HHV-6 therapy (including modes of action and resistance mechanisms).
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Affiliation(s)
- Leen De Bolle
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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19
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Burgoon MP, Gilden DH, Owens GP. B cells in multiple sclerosis. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2004; 9:786-96. [PMID: 14766408 PMCID: PMC3291127 DOI: 10.2741/1278] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The most common laboratory abnormality in multiple sclerosis (MS) is an increased amount of cerebrospinal fluid IgG and the presence of oligoclonal bands. Despite studies of the humoral response that suggest the involvement of an infectious agent or autoantigen in disease, the major targets of the oligoclonal response are still unknown. Identification of these targets will reveal valuable insights into the cause and pathogenesis of MS and is likely to lead to effective treatment.
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Affiliation(s)
- Mark P Burgoon
- Department of Neurology, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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20
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Soldan SS, Jacobson S. Infection and Multiple Sclerosis. INFECTION AND AUTOIMMUNITY 2004. [PMCID: PMC7152275 DOI: 10.1016/b978-044451271-0.50044-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Kong H, Baerbig Q, Duncan L, Shepel N, Mayne M. Human herpesvirus type 6 indirectly enhances oligodendrocyte cell death. J Neurovirol 2003; 9:539-50. [PMID: 13129768 DOI: 10.1080/13550280390241241] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Accumulating evidence suggests that human herpesvirus type 6 (HHV-6) plays a pathogenic role in diseases of the central nervous system including multiple sclerosis (MS). Recent studies have indicated that HHV-6 DNA is detected with high frequency in MS lesions compared to normal-appearing white matter, implicating a role for HHV-6 in MS pathogenesis. It appears that T cells, which infiltrate into the brain in MS patients, and resident oligodendrocytes harbor HHV-6 virus in MS lesions. Because T cells infected with HHV-6 have elevated proinflammatory gene expression, we hypothesized that HHV-6 could be indirectly cytotoxic to glial cells, including oligodendrocytes. Supernatants from SupT1 cells infected with HHV-6 variant A (GS or U1102) or variant B (Z29) significantly reduced MO3.1 cell proliferation by 75% +/- 10%, 78% +/- 8% or 51% +/- 9%, respectively. HHV-6 viral supernatants (GS or U1102 or Z29) significantly increased MO3.1 or primary human oligodendrocyte precursor cells (OPCs) cell death, whereas primary human fetal astrocytes were not affected. Removal of HHV-6 virions or proteins by trypsin treatment from culture supernatants did not reverse the loss in oligodendrocyte proliferation or viability. Supernatants from HHV-6 GS or U1102 cultures were significantly more cytotoxic to MO3.1 cells or OPCs compared to supernatants from T cells infected with Z29. Dying oligodendrocytes did not have an apoptotic-like phenotype and toxicity was not inhibited by general inhibitor of apoptosis, ZVAD. Further, oligodendrocytes had minimal caspase-3 activation even in the presence of staurosporine, suggesting that cell death followed caspase-independent pathways. These results indicate that HHV-6 is indirectly cytotoxic to oligodendrocytes and that cell death is driven primarily by caspase-independent pathways.
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Affiliation(s)
- Hong Kong
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada
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22
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Swanborg RH, Whittum-Hudson JA, Hudson AP. Infectious agents and multiple sclerosis--are Chlamydia pneumoniae and human herpes virus 6 involved? J Neuroimmunol 2003; 136:1-8. [PMID: 12620637 DOI: 10.1016/s0165-5728(02)00465-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A good deal of evidence suggests an infectious component in the development of multiple sclerosis (MS) and, to date, some 20 bacteria and viruses have been associated with the disease. Recent independent sets of studies have implicated the respiratory bacterium Chlamydia pneumoniae and human herpes virus 6 (HHV-6) in the pathogenesis of MS. However, as is the case for essentially all earlier microbial associations, experimental evidence linking either this bacterium or this virus to MS is equivocal. We review the published reports concerning involvement of C. pneumoniae and HHV-6 in MS, and data relating to possession of the APOE epsilon 4 allele, which some studies indicate might influence how these or other pathogens affect disease genesis. Based on the large set of inconsistent observations available and given important new information regarding the neuropathology of MS, we contend that no conclusion is possible at this point regarding the potential role of either C. pneumoniae or HHV-6 in MS. We therefore propose future studies that should clarify whether, and if so how, these and other organisms function in the pathogenesis of this disease.
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Affiliation(s)
- Robert H Swanborg
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Gordon H. Scott Hall, 540 East Canfield Avenue, Detroit, MI 48201, USA
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23
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Fogdell-Hahn A, Soldan SS, Jacobson S. Association of chronic progressive neurological disease and ubiquitous viral agents: lessons from human herpesvirus 6 and multiple sclerosis. Mol Psychiatry 2003; 7 Suppl 2:S29-31. [PMID: 12142941 DOI: 10.1038/sj.mp.4001172] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- A Fogdell-Hahn
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke/NIH, 9000 Rockville Pike, Building 10, Room 5B-16, Bethesda, MD 20892, USA
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24
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Tejada-Simon MV, Zang YCQ, Hong J, Rivera VM, Zhang JZ. Cross-reactivity with myelin basic protein and human herpesvirus-6 in multiple sclerosis. Ann Neurol 2003; 53:189-97. [PMID: 12557285 DOI: 10.1002/ana.10425] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Viral infections are though to play an important role in the pathogenesis of multiple sclerosis (MS) potentially through molecular mimicry. An identical sequence was found in both myelin basic protein (MBP, residues 96-102), a candidate autoantigen for MS, and human herpesvirus-6 (HHV-6 U24, residues 4-10) that is a suspected viral agent associated with MS. In this study, we showed that greater than 50% of T cells recognizing MBP(93-105) cross-reacted with and could be activated by a synthetic peptide corresponding to residues 1 to 13 of HHV-6 U24 in MS patients. The estimated precursor frequency of these cross-reactive T cells recognizing both peptides, MBP(93-105) and HHV-6 (U24)(1-13), was significantly elevated in MS patients compared with that in healthy controls. These cross-reactive CD4+ T cells represented the same Th1 phenotype as that of monospecific T cells recognizing MBP(93-105). There were increased antibody titers for both peptide HHV-6 (U24)(1-13) and peptide MBP(93-105) in the same patients with MS compared with those in healthy controls, suggesting B-cell sensitization to the antigens in MS patients. The study provides important evidence in the understanding of the potential role of HHV-6 infection/reactivation in the activation of autoimmune reactivity to MBP and its implication in the pathogenesis of MS.
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Affiliation(s)
- Maria V Tejada-Simon
- Multiple Sclerosis Research Unit, Department of Neurology and Baylor Multiple Sclerosis Center, Baylor College of Medicine, Houston, TX 77030, USA
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25
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Swanborg RH, Whittum-Hudson JA, Hudson AP. Human herpesvirus 6 and Chlamydia pneumoniae as etiologic agents in multiple sclerosis - a critical review. Microbes Infect 2002; 4:1327-33. [PMID: 12443897 DOI: 10.1016/s1286-4579(02)00009-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Multiple sclerosis (MS) is thought by many investigators to have an infectious component, and several microorganisms have been associated with the disease during the last three decades. Recent studies have implicated both human herpesvirus 6 (HHV-6) and the obligate intracellular bacterium Chlamydia pneumoniae in the etiology of MS. As with earlier studies of other potential agents, however, evidence linking either of these organisms to the disease is equivocal. In this article, we review data for and against involvement of HHV-6 and C. pneumoniae in MS, as well as evidence concerning auxiliary factors, such as possession of the APOE epsilon4 allele, which may influence the role of these organisms in pathogenesis. Further, we suggest several lines of investigation that should clarify whether either or both pathogens are associated meaningfully with this disease.
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Affiliation(s)
- Robert H Swanborg
- Department Immunology, Wayne State University School of Medicine, Detroit, MI 48201, USA
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26
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Caselli E, Boni M, Bracci A, Rotola A, Cermelli C, Castellazzi M, Di Luca D, Cassai E. Detection of antibodies directed against human herpesvirus 6 U94/REP in sera of patients affected by multiple sclerosis. J Clin Microbiol 2002; 40:4131-7. [PMID: 12409386 PMCID: PMC139661 DOI: 10.1128/jcm.40.11.4131-4137.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association between human herpesvirus 6 (HHV-6) and multiple sclerosis (MS) is controversial. In fact, it is difficult to establish a causative role of HHV-6, due to the high prevalence of latently infected individuals in the healthy population. Therefore, the presence of virus sequences in tissue biopsy does not support a viral role, and serological assays do not show significant differences between MS patients and control populations. The only viral gene expressed during latency is U94/rep. Therefore, we have developed a serological assay for the detection of antibodies specifically directed against U94/REP protein. Different populations were analyzed by enzyme-linked immunosorbent assay, including healthy controls, MS patients, and subjects with diseases unrelated to HHV-6 infection, including other neurological diseases. The results show statistically significant differences (P > 0.01) between MS patients and control groups, both in antibody prevalence (87 and 43.9%, respectively) and in geometric mean titer (1:515 and 1:190, respectively). The detection of antibodies specific for HHV-6 U94/REP shows that the immune system is exposed to this antigen during natural infection. The higher prevalence and higher titers of antibodies to U94/REP suggest that MS patients and control groups might experience different exposures to HHV-6.
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Affiliation(s)
- Elisabetta Caselli
- Section of Microbiology, Department of Experimental and Diagnostic Medicine. Section of Neurology, Department of Medical Surgical, Communication and Behavioral Sciences, University of Ferrara, Ferrara, Italy
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27
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Cirone M, Cuomo L, Zompetta C, Ruggieri S, Frati L, Faggioni A, Ragona G. Human herpesvirus 6 and multiple sclerosis: a study of T cell cross-reactivity to viral and myelin basic protein antigens. J Med Virol 2002; 68:268-72. [PMID: 12210418 PMCID: PMC7167112 DOI: 10.1002/jmv.10190] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2002] [Indexed: 11/10/2022]
Abstract
Several reports have suggested an association of human herpesvirus 6 (HHV-6) with multiple sclerosis. Autoreactive T lymphocytes directed against myelin components seem to contribute to the pathogenesis of the disease. It has been suggested that molecular mimicry between viral and self-antigens might be one of the mechanisms that determine the onset of several autoimmune diseases. Following this hypothesis, the purpose of the present study was to evaluate if HHV-6 could play a role in activating T cells capable of cross-reaction with an important myelin component, the myelin basic protein. T cell lines were established from 22 multiple sclerosis patients and from 16 healthy controls, and their capability to react to both virus and myelin basic protein antigens was compared. The analysis of T cell cross-reactivity in patients and controls did not show significant differences in the HHV-6 ability to activate myelin basic protein-reactive T cells. Similarly, the evaluation of the humoral immune response to HHV-6 in patients and controls did not mirror any abnormality in the HHV-6 status in multiple sclerosis patients. Therefore, although the findings of activity in vitro of T cell lines with dual specificity are consistent with the hypothesis of molecular mimicry, the lack of differences in cross-reactivity between patients and controls do not support molecular mimicry as an important mechanism in the physiopathology of this disease.
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Affiliation(s)
- Mara Cirone
- Dipartimento di Medicina Sperimentale e Patologia, Università “La Sapienza,” Roma, Italy
| | - Laura Cuomo
- Istituto Neurologico Mediterraneo “Neuromed,” Pozzilli, Italy
| | - Claudia Zompetta
- Dipartimento di Medicina Sperimentale e Patologia, Università “La Sapienza,” Roma, Italy
| | - Stefano Ruggieri
- Istituto Neurologico Mediterraneo “Neuromed,” Pozzilli, Italy
- Dipartimento di Neuroscienze, Università “La Sapienza,” Roma, Italy
| | - Luigi Frati
- Dipartimento di Medicina Sperimentale e Patologia, Università “La Sapienza,” Roma, Italy
- Istituto Neurologico Mediterraneo “Neuromed,” Pozzilli, Italy
| | - Alberto Faggioni
- Dipartimento di Medicina Sperimentale e Patologia, Università “La Sapienza,” Roma, Italy
| | - Giuseppe Ragona
- Dipartimento di Medicina Sperimentale e Patologia, Università “La Sapienza,” Roma, Italy
- Istituto Neurologico Mediterraneo “Neuromed,” Pozzilli, Italy
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28
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Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Significant progress has been made in our understanding of the etiology of MS. MS is widely believed to be an autoimmune disease that results from aberrant immune responses to CNS antigens. T cells are considered to be crucial in orchestrating an immunopathological cascade that results in damage to the myelin sheath. This review summarizes the currently available data supporting the idea that myelin reactive T cells are actively involved in the immunopathogenesis of MS. Some of the therapeutic strategies for MS are discussed with a focus on immunotherapies that aim to specifically target the myelin reactive T cells.
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Affiliation(s)
- Niels Hellings
- Biomedical Research Institute, Limburg University Center, School for Life Sciences, Transnational University Diepenbeek, Belgium
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29
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Nielsen L, Vestergaard BF. A mu-capture immunoassay for detection of human herpes virus-6 (HHV-6) IgM antibodies in human serum. J Clin Virol 2002; 25:145-54. [PMID: 12367648 DOI: 10.1016/s1386-6532(01)00256-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Human herpes virus-6 (HHV-6) was first isolated in 1986. It has been shown to cause exanthema subitum and has been associated with various other diseases. HHV-6 infection is widespread, and more than 90% of the population have antibodies against HHV-6 at the age of 2 years. Once acquired, the virus remains latent in the body. This makes it difficult to draw any conclusions about a causal relationship between the demonstration of HHV-6 and a specific disease. OBJECTIVES This work was to develop a mu-capture HHV-6 IgM enzyme linked immuno sorbent assay (ELISA) for use in routine diagnosis and for wide scale patient population analysis. STUDY DESIGN A mu-capture HHV-6 IgM ELISA was established. A total of 682 sera consisting of 585 sera from Danish blood donors and 97 sera from patients with autoimmune antibodies were analysed in the HHV-6 IGM ELISA. One hundred and ninety-two sera had earlier been analysed for total HHV-6 antibody content in a competitive ELISA, 94 sera were analysed for cytomegalovirus (CMV) IgM and 57 sera for Epstein Barr virus (EBV) antibodies, using different ELISA assays. The results for 12 primary infections with HHV-6 are also reported. RESULTS A HHV-6 IgM optical density (OD)-ratio was calculated according to a constant positive control. An empirical cut off of 0.5 HHV-6 IgM OD-ratio was chosen (with regard to the 10 HHV-6 seroconverters), which resulted in a specificity of 97.5% of the HHV-6 IgM ELISA. Two of the three donor sera with HHV-6 IgM OD-ratios more than 1.05 had total HHV-6 antibody titers significantly above the group with IgM OD-ratios below 0.7 consisting with HHV-6 reactivation. There was no cross reactions to EBV or CMV IgM positive sera. CONCLUSION The HHV-6 IgM ELISA seems valid to diagnose primary HHV-6 infection in particular in combination with the HHV-6 total antibody assay.
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Affiliation(s)
- Lene Nielsen
- Department of Virology, Statens Seruminstitut, Artillerivej 5, DK 2300, Copenhagen S, Denmark.
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30
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Abstract
OBJECTIVES To systematically review the published evidence for a relationship between human herpes virus 6 (HHV-6) and multiple sclerosis (MS). MATERIALS AND METHODS The medical literature was searched using MEDLINE and the Cochrane database. Retrieved studies are presented according to the experimental technique(s) used. The studies are rated for quality using a priori defined criteria. RESULTS Twenty-eight studies were retrieved. A total of 12 different experimental techniques were used. Four of these techniques provided evidence for a relationship between HHV-6 and MS, but none were able to show a causative relationship. CONCLUSIONS The available literature provides some support for a relationship between HHV-6 and MS. The limitations of the available studies and directions for future research are discussed.
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Affiliation(s)
- F G A Moore
- Department of Nurology, McGill University, Montereal, Quebec, Canada.
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31
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Tejada-Simon MV, Zang YCQ, Hong J, Rivera VM, Killian JM, Zhang JZ. Detection of viral DNA and immune responses to the human herpesvirus 6 101-kilodalton virion protein in patients with multiple sclerosis and in controls. J Virol 2002; 76:6147-54. [PMID: 12021348 PMCID: PMC136216 DOI: 10.1128/jvi.76.12.6147-6154.2002] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Accepted: 03/19/2002] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6 (HHV-6), a latent lymphotropic and neurotropic virus, has been suspected as an etiologic agent in multiple sclerosis (MS). The study was undertaken to correlate virologic evidence for HHV-6 activity with the state of host immunity to HHV-6 in MS patients and control subjects. The study revealed that cell-free DNA of HHV-6 was detected more frequently in both serum and cerebrospinal fluid of MS patients than in those of control subjects. T cells recognizing the recombinant 101-kDa protein (101K) corresponding to the major immunoreactive region unique to HHV-6 occurred at significantly lower precursor frequency in MS patients than in control subjects. The resulting HHV-6-specific T-cell lines obtained from MS patients exhibited skewed cytokine profiles characterized by the inability to produce interleukin-4 (IL-4) and IL-10. The decreased T-cell responses to HHV-6 and the altered cytokine profile were consistent with significantly declined serum immunoglobulin G (IgG) titers for HHV-6 of MS patients compared to those of control subjects. In contrast, elevated serum IgM titers for HHV-6 were detected in the majority of MS patients, which may reflect frequent exposure of B cells to HHV-6. The findings suggest that the decreased immune responses to HHV-6 may be responsible for ineffective clearance of HHV-6 in MS patients.
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Affiliation(s)
- Maria V Tejada-Simon
- Multiple Sclerosis Research Unit, Department of Neurology and Baylor-Methodist Multiple Sclerosis Center, Baylor College of Medicine, Houston, Texas 77030, USA
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32
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Berti R, Brennan MB, Soldan SS, Ohayon JM, Casareto L, McFarland HF, Jacobson S. Increased detection of serum HHV-6 DNA sequences during multiple sclerosis (MS) exacerbations and correlation with parameters of MS disease progression. J Neurovirol 2002; 8:250-6. [PMID: 12053279 DOI: 10.1080/13550280290049615-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In recent years, human herpesvirus 6 (HHV-6) has been investigated as a possible causative agent for MS. To determine if the detection of HHV-6 DNA in the serum of MS patients correlates with clinical parameters of MS disease progression, a total of 215 serum samples was obtained from 59 MS patients followed prospectively for a 5-month period. These samples were analyzed for the presence of HHV-6 DNA by nested PCR and compared in parallel to MS disease activity. HHV-6 DNA was amplified in 22% (4/18) of samples obtained during a period of clinical exacerbation. Significantly fewer (P = 0.008) sera, 5.6% (11/197), obtained from MS patients during clinical remission tested positive for the presence of HHV-6 DNA. This work demonstrates that the detection of serum HHV-6 DNA is significantly correlated with clinical exacerbations in MS. Moreover, the findings presented in this study have confirmed previous reports supporting an association between MS and HHV-6 and suggest a role for this human herpesvirus in the pathogenesis of MS.
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Affiliation(s)
- Rossana Berti
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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33
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White AR, Dutton NS, Cook RD. Isolation and growth of a cytopathic agent from multiple sclerosis brain tissue. J Neurovirol 2002; 8:111-21. [PMID: 11935463 DOI: 10.1080/13550280290049543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Although many studies support a role for viruses in multiple sclerosis (MS) etiopathology, no specific agent has been consistently associated with significant numbers of MS patients without concomitant detection in non-MS controls. Previous studies have shown the presence of viral-like structures in MS plaques, although the specificity of these structures for MS has been questioned. The present study describes the use of polyclonal antisera against feline and human brain-derived cytopathic agents and immunoaffinity chromatography to purify and partially characterize possible virus-like structures from MS brain tissue. Chromatography eluates from 4 MS brains contained pleomorphic particles up to 350 nm in diameter and tubular/filamentous-like structures approximately 10-18 nm in thickness. Inoculation of primary rat glial cell cultures with chromatography eluates from MS brain tissue resulted in a reproducible pattern of cytopathic effects in the form of multinucleation in cells identified immunocytochemically as oligodendrocytes. Antisera raised against the feline and MS-derived cytopathic agents were used to successfully immunolabel infected oligodendrocyte-like cells and syncytia and to detect a 66,000 M(r) protein on Western blots of inoculated cultures or concentrated MS brain eluates. Similar structures, cytopathic effects (CPE) and protein expression were not observed in eluates from 5 control brains or in cultures inoculated with control brain eluates. These studies demonstrate that cytopathic, virus-like structures can be isolated from MS brain tissue using antisera raised against a cytopathic agent rescued from demyelinating brain lesions in cats. The identity of this agent and its possible role in MS aetio-pathology remains unknown.
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Affiliation(s)
- Anthony R White
- Veterinary and Biomedical Sciences, Murdoch University, Western Australia.
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34
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Enbom M. Multiple sclerosis and Kaposi's sarcoma--chronic diseases associated with new human herpesviruses? SCANDINAVIAN JOURNAL OF INFECTIOUS DISEASES 2002; 33:648-58. [PMID: 11669221 DOI: 10.1080/00365540110027015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Two diseases that for many years have been suspected to be of viral origin are multiple sclerosis (MS) and Kaposi's sarcoma (KS). With the use of a new technique called representational difference analysis both these diseases have recently been associated with new lymphotropic herpesviruses, i.e. human herpesviruses (HHV) 6 and 8. HHV-6 is a ubiquitous virus and the etiological agent of exanthema subitum. Viral neuroinvasion occurs frequently in primary HHV-6 infection, and meningitis, encephalitis and demyelination have been described as rare complications. A relation with MS has been suggested for HHV-6, as the virus has been detected in MS plaques in the brain. Data from different studies are, however, conflicting and a definitive role for HHV-6 in MS pathogenesis has not been established. HHV-8 is believed to be the causative agent of KS, and is also associated with some rare hematological malignancies. The viral genome contains several potential oncogenes that are believed to have been picked up from the human genome during evolution. The role of HHV-8 in healthy, immunocompetent individuals is however uncertain. In conclusion, the full spectrum of human diseases associated with these new viruses is not yet understood, and rapid developments in molecular biology will continue to shed new light on the interactions between herpesviruses and their hosts.
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Affiliation(s)
- M Enbom
- Department of Virology, Swedish Institute for Infectious Disease Control, Solna
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35
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Abstract
A number of herpes- and poxviruses encode 7TM G-protein coupled receptors most of which clearly are derived from their host chemokine system as well as induce high expression of certain 7TM receptors in the infected cells. The receptors appear to be exploited by the virus for either immune evasion, cellular reprogramming, tissue targeting or for cell entry. Through their efficient evolutionary machinery and through in vivo selection performed directly on the human cellular and molecular targets, virus have been able to optimize the encoded receptors for distinct pharmacological profiles to help in various parts of the viral life cyclus. Most of the receptors encoded by human pathogenic virus are still orphan receptors, i.e. the endogenous ligand is unknown. In the few cases where it has been possible to characterize these receptors pharmacologically, they have been found to bind a broad spectrum of either CC chemokines, US28 from human cytomegalovirus, or CXC chemokines, ORF74 from human herpesvirus 8. Nevertheless, US28 has been specifically optimized for recognition of the membrane bound chemokine, fractalkine, conceivably involved in cell-cell transfer of virus; whereas ORF74 among the endogenous CXC chemokines has selected angiogenic chemokines as agonists and angiostatic/modulatory chemokines as inverse agonists. ORF74 possess substantial cell-transforming properties and signals with high constitutive activity through the phospholipase C and MAP kinase pathways. Interestingly, transgenic expression of this single gene in certain lymphocyte cell lineages leads to the development of lesions which are remarkably similar to Kaposi's sarcoma, a human herpesvirus 8 associated disease. Thus, this and other virally encoded 7TM receptors appear to be attractive future drug targets.
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Affiliation(s)
- M M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Pharmacology, Panum Institute, DK-2200, Denmark
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36
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Abstract
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system whose cause is still unknown. Many findings suggest an infectious etiology or, at least, that infectious agents in association with host genetic factors may play a role in the pathogenesis of this disease. Accumulating data, including animal models, human models of virus induced demyelination, epidemiologic, and laboratory findings, demonstrate that viruses and host genetic factors can interact to cause immune-mediated demyelination. While many viruses have been postulated as a possible cause of MS, to date, no "MS virus" has been definitively shown to be associated with this disease. Alternatively, ubiquitous viruses are being considered as the environmental "triggers" that have been postulated to be involved in the MS disease process. We will focus on recent studies with human herpesvirus 6 and MS as how a common virus may be associated with this disorder in a subset of infected individuals.
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Affiliation(s)
- C Cermelli
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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37
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Abstract
Multiple sclerosis (MS) is the most prevalent demyelinating disease of young adults, affecting an estimated 300,000 individuals in the United States alone. The majority of affected individuals have a relapsing–remitting course while a smaller subset has a more chronic–progressive presentation. Women are affected more often than men, a phenomenon associated with a number of auto-immune diseases. Although the etiology of MS is unknown, it is generally believed that genetic, immunologic, and environmental factors are involved. This chapter discusses these issues as they suggest that exogenous factors are associated with the pathogenesis of this disorder. Recently, the human herpes virus 6 (HHV-6) has received considerable attention as an infectious agent candidate that might be associated with the pathogenesis of MS. The chapter focuses on this agent and the data that support the role of this virus in MS disease pathogenesis. A model is proposed, whereby in genetically susceptible individuals, multiple viruses may trigger either a virus-specific or a cross-reactive auto-immune response that results in clinical MS. Epidemiologic evidence suggests that it is a multifactorial disease that develops as a result of host genetics, immune response, and environment.
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Affiliation(s)
- S S Soldan
- Viral Immunology Section, NIH/NINDS, Bethesda, Maryland 20892, USA
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38
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Knox KK, Brewer JH, Henry JM, Harrington DJ, Carrigan DR. Human herpesvirus 6 and multiple sclerosis: systemic active infections in patients with early disease. Clin Infect Dis 2000; 31:894-903. [PMID: 11049767 DOI: 10.1086/318141] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/1999] [Revised: 02/23/2000] [Indexed: 11/03/2022] Open
Abstract
By means of immunohistochemical staining, cells actively infected with human herpesvirus 6 (HHV-6) were found in central nervous system tissues from 8 (73%) of 11 patients with definite multiple sclerosis (MS). Interestingly, 17 (90%) of 19 tissue sections showing active demyelination were positive for HHV-6-infected cells compared with only 3 (13%) of 23 tissue sections free of active disease (P<.0001). Central nervous system tissues from 2 of 28 normal persons and patients with other inflammatory demyelinative diseases were positive for HHV-6-infected cells (P<.0001), and the 2 positive cases were diagnosed as having HHV-6 leukoencephalitis. By use of a rapid culture assay, blood samples from 22 (54%) of 41 patients with definite MS were found to contain active HHV-6 infections, compared with 0 of 61 normal controls (P<.0001). No significant difference was found between HHV-6 viremia-positive and HHV-6 viremia-negative MS patients with respect to type of disease (relapsing/remitting or progressive). In contrast, patients with active HHV-6 viremia were significantly younger and had shorter durations of disease than did HHV-6 viremia-negative patients.
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Affiliation(s)
- K K Knox
- Institute for Viral Pathogenesis, Milwaukee, WI 53226, USA.
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39
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Hunter SF, Hafler DA. Ubiquitous pathogens: links between infection and autoimmunity in MS? Neurology 2000; 55:164-5. [PMID: 10908883 DOI: 10.1212/wnl.55.2.164] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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40
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Abstract
Human herpesvirus 6 (HHV-6), a member of the beta-herpesvirinae subfamily, is highly seroprevalent, has a worldwide distribution, and infection usually occurs within the first two years of life. In this age group, HHV-6 causes febrile illness including exanthem subitum with seizures a recognised complication. The virus is predominantly T lymphotropic although it can infect a variety of cell types in vitro and CD46 has recently been identified as a cellular receptor. The virus persists in the host, with a latent state proposed in monocytes and bone marrow progenitor cells, and chronic infection in salivary glands. The virus is pathogenic in the post transplantation period and may be a cofactor in the progression of HIV disease. The virus has also been associated with multiple sclerosis (MS), with the virus detected in oligodendrocytes particularly in plaque regions. The role of HHV-6 in MS remains controversial and a more extensive understanding of its neurotropism and association with disease is required. Two variants of HHV-6 exist (A and B) and comparison of their complete nucleotide sequences shows the genomes to be colinear, with a high degree of homology. Variation in specific regions of the genome is more extensive and probably accounts for biological and pathological differences. Almost exclusively, variant B is associated with febrile illness in childhood and is the predominant variant detected in healthy individuals. The epidemiology of HHV-6A infection needs to be better defined, although it is significantly less prevalent. Biological, genetic, epidemiological and pathological findings suggest that the two variants are divergent.
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Affiliation(s)
- D A Clark
- Department of Virology, Royal Free and University College Medical School, London, UK
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