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Carpentier PA, Getts MT, Miller SD. Pro-inflammatory functions of astrocytes correlate with viral clearance and strain-dependent protection from TMEV-induced demyelinating disease. Virology 2008; 375:24-36. [PMID: 18289626 DOI: 10.1016/j.virol.2008.01.024] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2007] [Revised: 01/03/2008] [Accepted: 01/15/2008] [Indexed: 12/11/2022]
Abstract
Intracerebral infection of susceptible strains of mice, e.g. SJL/J, with Theiler's murine encephalomyelitis virus (TMEV) leads to a persistent CNS infection accompanied by development of a chronic-progressive inflammatory CNS autoimmune demyelinating disease which is clinically and pathologically similar to human multiple sclerosis. In contrast, resistant strains of mice, e.g. C57BL/6 (B6), effectively clear TMEV from the CNS and do not develop demyelinating disease. Although CD8(+) T cells are crucial for viral clearance in B6 mice, SJL mice also mount potent CD8(+) T cell responses against virus, thus the reason for the viral persistence in the CNS in these mice is unclear. Here, we examined innate anti-viral responses of CNS-resident astrocytes as a potential determinant of viral persistence and disease susceptibility. We demonstrate that B6 astrocytes produce significantly higher levels of cytokines, chemokines and adhesion molecules in response to TMEV infection, or stimulation with IFN-gamma and TNF-alpha or poly I:C than SJL mice. In addition, TMEV more effectively induces MHC I molecules on B6 astrocytes than SJL, corresponding with an increased ability to activate TMEV-specific CD8(+) T cells directly ex vivo. These results suggest that enhanced anti-viral responses of B6 astrocytes contribute to the ability of these mice to clear TMEV from the CNS and therefore to their resistance to the development of autoimmune demyelinating disease.
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Affiliation(s)
- Pamela A Carpentier
- Northwestern University Feinberg School of Medicine, Department of Microbiology-Immunology, Interdepartmental Immunobiology Center, 303 E. Chicago Avenue, Chicago, IL 60611, USA
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102
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Abstract
To determine whether an immunological or pharmaceutical product has potential for therapy in treating multiple sclerosis (MS), detailed animal models are required. To date many animal models for human MS have been described in mice, rats, rabbits, guinea pigs, marmosets, and rhesus monkeys. The most comprehensive studies have involved murine experimental allergic (or autoimmune) encephalomyelitis (EAE), Semliki Forest virus (SFV), mouse hepatitis virus (MHV), and Theiler’s murine encephalomyelitis virus (TMEV). Here, we describe in detail multispecies animal models of human MS, namely EAE, SFV, MHV, and TMEV, in addition to chemically induced demyelination. The validity and applicability of each of these models are critically evaluated.
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103
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Autoimmune Processes in the Central Nervous System. HANDBOOK OF NEUROCHEMISTRY AND MOLECULAR NEUROBIOLOGY 2008. [PMCID: PMC7121640 DOI: 10.1007/978-0-387-30398-7_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this chapter we discuss the factors that contribute to the unique immunological environment of the central nervous system and the mechanisms that may account for the development of autoimmunity within the CNS, including infectious agents as inducers of autoimmune disease. Consideration is given to a variety of human neurological diseases of autoimmune or presumed autoimmune etiology: autism, neuromyelitis optica, neuromyotonia, schizophrenia, lethargic encephalitis and stiff‐man syndrome. Also, we discuss autoimmunity as a possible mediator of CNS repair and examples of the protective effects of bacterial and helminth infections on CNS disease. Multiple sclerosis and models of multiple sclerosis are discussed with special attention given to the Theiler's virus‐induced demyelination model.
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104
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Roussarie JP, Ruffié C, Edgar JM, Griffiths I, Brahic M. Axon myelin transfer of a non-enveloped virus. PLoS One 2007; 2:e1331. [PMID: 18159229 PMCID: PMC2137932 DOI: 10.1371/journal.pone.0001331] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Accepted: 11/27/2007] [Indexed: 11/19/2022] Open
Abstract
We showed previously that Theiler's virus, a neurotropic non-enveloped picornavirus of mouse, traffics from the axon of infected neurons into the surrounding myelin. When this traffic is interrupted, as in the shiverer mouse which bears a mutation in the myelin basic protein gene, the virus is unable to persist in the central nervous system. In the present work, we used the Wld(s) mutant mouse, a strain in which axonal degeneration is considerably slowed down, to show that axon to myelin traffic takes place in the absence of axon degeneration. Our results suggest the existence of a mechanism of transfer of axonal cytoplasm into the myelin which Theiler's virus might exploit to ensure its persistence.
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Affiliation(s)
- Jean-Pierre Roussarie
- Department of Virology, URA3015 Centre National de la Recherche Scientifique (CNRS), Institut Pasteur, Paris, France
| | - Claude Ruffié
- Department of Virology, URA3015 Centre National de la Recherche Scientifique (CNRS), Institut Pasteur, Paris, France
| | - Julia M. Edgar
- Applied Neurobiology Group, Institute of Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Ian Griffiths
- Applied Neurobiology Group, Institute of Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Michel Brahic
- Department of Virology, URA3015 Centre National de la Recherche Scientifique (CNRS), Institut Pasteur, Paris, France
- * To whom correspondence should be addressed. E-mail:
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105
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Silverman RH. Viral encounters with 2',5'-oligoadenylate synthetase and RNase L during the interferon antiviral response. J Virol 2007; 81:12720-9. [PMID: 17804500 PMCID: PMC2169107 DOI: 10.1128/jvi.01471-07] [Citation(s) in RCA: 454] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Robert H Silverman
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue NB40, Cleveland, OH 44195, USA.
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106
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Meagher MW, Johnson RR, Young EE, Vichaya EG, Lunt S, Hardin EA, Connor MA, Welsh CJR. Interleukin-6 as a mechanism for the adverse effects of social stress on acute Theiler's virus infection. Brain Behav Immun 2007; 21:1083-95. [PMID: 17591434 PMCID: PMC2538675 DOI: 10.1016/j.bbi.2007.05.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2006] [Revised: 05/02/2007] [Accepted: 05/04/2007] [Indexed: 12/29/2022] Open
Abstract
Prior exposure to social disruption stress (SDR) exacerbates both the acute and chronic phase of Theiler's murine encephalomyelitis virus infection (TMEV; [Johnson, R.R., Storts, R., Welsh, T.H., Jr., Welsh, C.J., Meagher, M.W., 2004. Social stress alters the severity of acute Theiler's virus infection. J. Neuroimmunol. 148, 74--85; Johnson, R.R., Prentice, T.W., Bridegam, P., Young, C.R., Steelman, A.J., Welsh, T.H., Welsh, C.J.R., Meagher, M.W., 2006. Social stress alters the severity and onset of the chronic phase of Theiler's virus infection. J. Neuroimmunol. 175, 39--51]). However, the neuroimmune mechanism(s) mediating this effect have not been determined. The present study examined whether stress-induced increases in the proinflammatory cytokine interleukin-6 (IL-6) contributes to the adverse effects of SDR on acute TMEV infection. Experiment 1 demonstrated that SDR increases central and peripheral levels of IL-6 and that this effect is reversed by intracerebral ventricular infusion of neutralizing antibody to IL-6 prior to each of six SDR sessions. Although SDR reduced the sensitivity of spleen cells to the anti-inflammatory effects of corticosterone, the neutralizing antibody to IL-6 did not alter this effect. To investigate whether stress-induced increases in IL-6 contribute to the exacerbation of acute TMEV infection, Experiment 2 examined whether intracerebral administration of neutralizing antibody to IL-6 during SDR would prevent the subsequent exacerbation of acute TMEV infection. Experiment 3 then replaced the social stress with intracerebral infusion of IL-6 to assess sufficiency. As expected, prior exposure to SDR subsequently increased infection-related sickness behaviors, motor impairment, CNS viral titers, and CNS inflammation. These deleterious effects of SDR were either prevented or significantly attenuated by intracerebral infusion of neutralizing antibody to IL-6 during the stress exposure period. However, infusion of IL-6 alone did not mimic the adverse effects of SDR. We conclude that IL-6 is necessary but not sufficient to exacerbate acute TMEV infection.
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Affiliation(s)
- Mary W Meagher
- Department of Psychology, College of Liberal Arts, Texas A&M University, College Station, TX 77843-4235, USA.
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107
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Hou W, So EY, Kim BS. Role of dendritic cells in differential susceptibility to viral demyelinating disease. PLoS Pathog 2007; 3:e124. [PMID: 17722981 PMCID: PMC1950949 DOI: 10.1371/journal.ppat.0030124] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Accepted: 07/09/2007] [Indexed: 02/07/2023] Open
Abstract
Although persistent viral diseases are a global health concern, the mechanisms of differential susceptibility to such infections among individuals are unknown. Here, we report that differential interactions between dendritic cells (DCs) and virus are critical in determining resistance versus susceptibility in the Theiler murine encephalomyelitis virus–induced demyelinating disease model of multiple sclerosis. This virus induces a chronic demyelinating disease in susceptible mice, whereas the virus is completely cleared in resistant strains of mice. DCs from susceptible mice are more permissive to viral infection, resulting in severe deficiencies in development, expansion, and function, in contrast to DCs from resistant mice. Although protective prior to viral infection, higher levels of type I interferons (IFNs) and IFN-γ produced by virus-infected DCs from susceptible mice further contribute to the differential inhibition of DC development and function. An increased DC number and/or acquired resistance of DCs to viral infection render susceptible mice resistant to viral persistence and disease progression. Thus, the differential permissiveness of DCs to infectious agents and its subsequent functional and developmental deficiencies determine the outcome of infection- associated diseases. Therefore, arming DCs against viral infection–induced functional decline may provide a useful intervention for chronic infection-associated diseases. Many chronic viral diseases are associated with prolonged viral persistence levels, which vary from one individual to another. However, the mechanisms of differential susceptibility to persistent viral infections are unknown. Theiler murine encephalomyelitis virus (TMEV) induces a chronic demyelinating disease similar to multiple sclerosis. In this study, we investigated the potential mechanisms of differential susceptibility to chronic viral persistence in the central nervous system following infection with TMEV. Our results indicate that differential interactions between virus and dendritic cells (DCs), leading to the induction of anti-viral immunity, are critical in determining resistance or susceptibility to virus-induced chronic demyelinating disease. DCs from susceptible mice are much more permissive to viral infection, resulting in severe deficiencies in their development, expansion, and function, whereas DCs from resistant mice are not permissive. Consequently, the DCs in susceptible mice are responsible for poor anti-viral T cell activation, permitting viral persistence and disease development in the host. Interestingly, the administration of additional DCs or pre-activated virus-resistant DCs enables susceptible mice to resist persistent viral infection and disease development. This knowledge may be useful in devising effective means to induce strong anti-viral immune responses, thereby protecting the host from virus-associated chronic diseases caused by persistent viral infection.
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Affiliation(s)
- Wanqiu Hou
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Eui Young So
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Byung S Kim
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * To whom correspondence should be addressed. E-mail:
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108
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Al-Salleeh F, Petro TM. TLR3 and TLR7 are involved in expression of IL-23 subunits while TLR3 but not TLR7 is involved in expression of IFN-beta by Theiler's virus-infected RAW264.7 cells. Microbes Infect 2007; 9:1384-92. [PMID: 17897860 DOI: 10.1016/j.micinf.2007.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2007] [Revised: 06/26/2007] [Accepted: 07/02/2007] [Indexed: 12/15/2022]
Abstract
Theiler's murine encephalomyelitis virus (TMEV) infects macrophages and causes demyelinating disease (DD) in certain mouse strains. IL-23 p19/p40 and IFN-beta, which are both expressed by macrophages in response to TMEV, could contribute to or prevent DD. Because TMEV may induce macrophages' cytokines through TLR3 and TLR7 (toll-like receptors), their role in TMEV-induced IL-23 and IFN-beta expression by the RAW264.7 macrophage cell line was determined following infection with TMEV or stimulation with the poly (I:C) or loxoribine. TMEV infection or stimulation with poly (I:C), a TLR3 agonist, or loxoribine, a TLR7 agonist, induced expression of IL-23 and IFN-beta in RAW264.7 cells. In addition, TMEV infection increased expression of TLR3 and TLR7 in RAW264.7 cells. Transfection of RAW264.7 cells with shRNA plasmid vectors expressing siRNA specific for TLR3 or TLR7 concomitantly decreased expression of TLR3 or TLR7, respectively, and TMEV-induced p19 mRNA, p19 protein, and IL-23 p19/p40. Transfection with TLR7-shRNA plasmids reduced expression of TMEV-induced p40 mRNA and p40 protein. However, transfection with TLR3-shRNA plasmids increased expression of TMEV-induced p40 mRNA but decreased p40 protein. In addition, transfection with TLR3-shRNA plasmids but not TLR7-shRNA plasmids decreased expression of TMEV-induced IFN-beta mRNA. Thus TLR3 and TLR7 contribute to TMEV-induced IL-23 p19 and p40, while TLR3 contributes to TMEV-induced IFN-beta.
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Affiliation(s)
- Fahd Al-Salleeh
- Department of Oral Biology, University of Nebraska Medical Center, 40th and Holdrege Streets, Lincoln, NE 68583-0740, USA
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109
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Levillayer F, Mas M, Levi-Acobas F, Brahic M, Bureau JF. Interleukin 22 is a candidate gene for Tmevp3, a locus controlling Theiler's virus-induced neurological diseases. Genetics 2007; 176:1835-44. [PMID: 17483407 PMCID: PMC1931528 DOI: 10.1534/genetics.107.073536] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 04/26/2007] [Indexed: 02/06/2023] Open
Abstract
After intracerebral inoculation, Theiler's virus induces in its natural host, the mouse, an acute encephalomyelitis followed, in susceptible animals, by chronic inflammation and primary demyelination. Susceptibility to demyelination among strains of laboratory mice is explained by the capacity of the immune system to control viral load during persistence. Also, differences of susceptibility to viral load between the susceptible SJL strain and the resistant B10.S strain are mainly due to two loci, Tmevp2 and Tmevp3, located close to the Ifng locus on chromosome 10. In this article, we show that the Tmevp3 locus controls both mortality during the acute encephalomyelitis and viral load during persistence. Most probably, two genes located in the Tmevp3 interval control these two different phenotypes with efficiencies that depend on the age of the mouse at inoculation. Il22, a member of the IL-10 cytokine family, is a candidate gene for the control of mortality during the acute encephalomyelitis.
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Affiliation(s)
- F Levillayer
- Unité des Virus Lents, URA CNRS1930, Institut Pasteur, 75724 Paris Cedex 15, France
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110
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Roussarie JP, Ruffié C, Brahic M. The role of myelin in Theiler's virus persistence in the central nervous system. PLoS Pathog 2007; 3:e23. [PMID: 17305428 PMCID: PMC1797621 DOI: 10.1371/journal.ppat.0030023] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Accepted: 01/03/2007] [Indexed: 11/19/2022] Open
Abstract
Theiler's virus, a picornavirus, persists for life in the central nervous system of mouse and causes a demyelinating disease that is a model for multiple sclerosis. The virus infects neurons first but persists in white matter glial cells, mainly oligodendrocytes and macrophages. The mechanism, by which the virus traffics from neurons to glial cells, and the respective roles of oligodendrocytes and macrophages in persistence are poorly understood. We took advantage of our previous finding that the shiverer mouse, a mutant with a deletion in the myelin basic protein gene (Mbp), is resistant to persistent infection to examine the role of myelin in persistence. Using immune chimeras, we show that resistance is not mediated by immune responses or by an efficient recruitment of inflammatory cells into the central nervous system. With both in vivo and in vitro experiments, we show that the mutation does not impair the permissiveness of neurons, oligodendrocytes, and macrophages to the virus. We demonstrate that viral antigens are present in cytoplasmic channels of myelin during persistent infection of wild-type mice. Using the optic nerve as a model, we show that the virus traffics from the axons of retinal ganglion cells to the cytoplasmic channels of myelin, and that this traffic is impaired by the shiverer mutation. These results uncover an unsuspected axon to myelin traffic of Theiler's virus and the essential role played by the infection of myelin/oligodendrocyte in persistence. Theiler's virus persists in the central nervous system of mice and causes a chronic disease that resembles multiple sclerosis, a common demyelinating disease of humans. The virus infects neurons for one to two weeks, but later on it persists in the white matter, in oligodendrocytes and also in macrophages. Oligodendrocytes are the myelin-making cells of the central nervous system. Strikingly, in mice with a genetic defect of myelin, the virus infects neurons normally but is unable to persist. Understanding the reason for the lack of persistence in this mutant mouse should pinpoint an essential step in the complex process resulting in persistence. In this article, we show that resistance to persistent infection is not mediated by the immune system and is not due to inefficient viral replication in oligodendrocytes or macrophages. Instead, we show that virus transported in axons traffics into the myelin, and that this traffic is interrupted by the myelin mutation. This unsuspected axon to myelin traffic of Theiler's virus is necessary for viral persistence. Our results warrant looking for a similar phenomenon in other persistent infections of the nervous system, including in humans.
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Affiliation(s)
- Jean-Pierre Roussarie
- Unité des Virus Lents, Département de Virologie, Institut Pasteur and Centre National de la Recherche Scientifique, Paris, France
| | - Claude Ruffié
- Unité des Virus Lents, Département de Virologie, Institut Pasteur and Centre National de la Recherche Scientifique, Paris, France
| | - Michel Brahic
- Unité des Virus Lents, Département de Virologie, Institut Pasteur and Centre National de la Recherche Scientifique, Paris, France
- * To whom correspondence should be addressed. E-mail:
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111
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Jones MS, Lukashov VV, Ganac RD, Schnurr DP. Discovery of a novel human picornavirus in a stool sample from a pediatric patient presenting with fever of unknown origin. J Clin Microbiol 2007; 45:2144-50. [PMID: 17460053 PMCID: PMC1933019 DOI: 10.1128/jcm.00174-07] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fever of unknown origin (FUO) is a serious problem in the United States. An unidentified agent was cultured from the stool of an infant who presented with FUO. This virus showed growth in HFDK cells and suckling mice. Using DNase sequence-independent single-primer amplification, we identified several nucleotide sequences with a high homology to Theiler's murine encephalomyelitis virus. Nearly full-length viral genome sequencing and phylogenetic analysis demonstrate that this virus is a member of the Cardiovirus genus of the Picornaviridae family.
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Affiliation(s)
- Morris S Jones
- Clinical Investigation Facility, David Grant USAF Medical Center, 101 Bodin Circle, Travis AFB, CA 94535, USA.
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112
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Lipton HL, Liang Z, Hertzler S, Son KN. A specific viral cause of multiple sclerosis: One virus, one disease. Ann Neurol 2007; 61:514-23. [PMID: 17455291 DOI: 10.1002/ana.21116] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
"Multiple sclerosis is an autoimmune disease," is heard so often that it is widely accepted as fact by the current generation of students and physicians. Yet, although it is undisputed that multiple sclerosis (MS) is immune mediated, an autoimmune mechanism remains unproven. Immune-mediated tissue damage can also result from viral infections in which the host immune response is directed to viral rather than self proteins, or as a consequence of nonspecific or bystander immune responses that change the local cytokine environment. Increasing evidence suggests that poorly controlled host immune responses account for much of the tissue damage in chronic infections, and it has been postulated that a similar mechanism may underlie many chronic diseases with features suggestive of an infectious causative factor, including MS. A recent study suggesting that oligodendrocyte death accompanied by microglial activation is the primary event in new MS lesion formation, rather than lymphocyte infiltration, could change the current mindset almost exclusively focused on autoimmunity. This review presents the rationale for considering MS a single disease caused by one virus, as well as the anticipated pattern of a persistent central nervous system infection, the application of Koch's postulates to viral discovery in MS as the causative agent, and tissue culture-independent genotypic approaches to viral discovery in MS.
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Affiliation(s)
- Howard L Lipton
- Department of Neurology, University of Illinois at Chicago, Chicago, IL 60612-7344, USA.
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113
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Myoung J, Hou W, Kang B, Lyman MA, Kang JA, Kim BS. The immunodominant CD8+ T cell epitope region of Theiler's virus in resistant C57BL/6 mice is critical for anti-viral immune responses, viral persistence, and binding to the host cells. Virology 2006; 360:159-71. [PMID: 17095033 PMCID: PMC1857342 DOI: 10.1016/j.virol.2006.09.045] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 09/07/2006] [Accepted: 09/26/2006] [Indexed: 11/16/2022]
Abstract
Theiler's virus infection induces an immune-mediated demyelinating disease, providing a relevant animal model of human multiple sclerosis. VP2(121-130)-specific CD8+ T cells in resistant H-2b mice account for the majority of CNS-infiltrating CD8+ T cells. To further study the role of the CD8(+) T cells, we generated a panel of mutant viruses substituted with L, G, or T at the anchor residue (M130) of the VP2(121-130) epitope. M130L virus (M130L-V) with a substitution of M with L displayed similar properties as wild-type virus (WT-V). However, M130G-V and M130T-V could not establish a persistent infection in the CNS. The level of both virus-specific CD8+ and CD4+ T cell responses is significantly reduced in mice infected with these variant viruses. While all mutant and wild-type viruses replicate comparably in BHK cells, replication of M130G-V and M130T-V in macrophages was significantly lower compared to those infected with WT-V and M130L-V. Interestingly, these mutant viruses deficient in replication in primary mouse cells showed drastically reduced binding ability to the cells. These results suggest that the anchor residue of the predominant CD8+ T cell epitope of TMEV in resistant mice is critical for the virus to infect target cells and this deficiency may result in poor viral persistence leading to correspondingly low T cell responses in the periphery and CNS. Thus, selection of the cellular binding region of the virus as the predominant epitope for CD8+ T cells in resistant mice may provide a distinct advantage in controlling viral persistence by preventing escape mutations.
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Affiliation(s)
| | | | | | | | | | - Byung S. Kim
- * All correspondence should be made to Dr. Byung S. Kim, Department of Microbiology-Immunology, Northwestern University Medical School, 303 East Chicago Ave., Chicago, IL 60611. E-mail: ; Tel. (312) 503-8693; Fax. (312) 503-1339
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114
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Ulrich R, Baumgärtner W, Gerhauser I, Seeliger F, Haist V, Deschl U, Alldinger S. MMP-12, MMP-3, and TIMP-1 are markedly upregulated in chronic demyelinating theiler murine encephalomyelitis. J Neuropathol Exp Neurol 2006; 65:783-93. [PMID: 16896312 DOI: 10.1097/01.jnen.0000229990.32795.0d] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Theiler murine encephalomyelitis (TME) represents a highly relevant viral model for multiple sclerosis. Matrix metalloproteinases (MMPs) degrade extracellular matrix molecules and are involved in demyelination processes. To elucidate their impact on demyelination in TME, spinal cords of TME virus (TMEV)-infected SJL/J mice were taken at 9 different time points postinfection (pi) ranging from 1 hour to 196 days pi and investigated for the expression of TMEV, MMP-2, -3, -7, -9, -10, -11, -12, -13, -14, -15, -24, and TIMP-1 to -4 by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). High TMEV RNA levels were detectable throughout the observation period using RT-qPCR. In addition, TMEV RNA was visualized within demyelinated lesions by in situ hybridization. MMP-3 mRNA was significantly upregulated at 1 day pi and again in the late phase of infection. TIMP-1 mRNA was significantly elevated throughout the observation period. MMP-12 mRNA was most prominently upregulated in the late phase of infection and MMP-12 protein was localized in intralesional microglia/macrophages and astrocytes by immunohistochemistry. In summary, in early TMEV infection, MMP-3 and TIMP-1 mRNA upregulation might be directly virus-induced, whereas persistent TMEV infection directly or indirectly stimulated MMP-12 production in microglia/macrophages and astrocytes and might account for ongoing demyelination in TME.
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Affiliation(s)
- Reiner Ulrich
- Department of Pathology, University of Veterinary Medicine Hannover, Germany
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115
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Kielczewska A, Vidal SM. Enemy at the gates: forward genetics of the mouse antiviral response. Curr Opin Immunol 2006; 18:617-26. [PMID: 16879955 DOI: 10.1016/j.coi.2006.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 07/20/2006] [Indexed: 01/20/2023]
Abstract
The environment and the genetic constitution of both the pathogen and the host influence the severity and the outcome of viral infections. Whereas identification of the host component in humans remains challenging, recent progress in defining genes through analysis of mouse models of infection presenting natural or chemically induced variation in host susceptibility mark a fruitful period of gene discovery. This includes recognition that UNC93B1, which encodes an endocytic protein, is a susceptibility gene, providing an unexpected entry point to our understanding of the response against herpesvirus infection. By contrast, elucidation of alternative mechanisms of host resistance against mouse cytomegalovirus in inbred mouse strains has led to new insights regarding molecular recognition of the infected cells by natural killer cell MHC class I receptors. In addition, the conservation of genetic and functional aspects between mouse and human is enabling a rational pursuit of potential cures. With the continuous development of resources for experimental investigation of the genome, the production of new mutant alleles, and the phenotypic characterization of new models of infection, we predict that mouse genetic models will make an increasing contribution to our understanding of the genetic puzzle of host response to virus infection.
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Affiliation(s)
- Agnieszka Kielczewska
- McGill Centre for the Study of Host Resistance, Department of Human Genetics, McGill University, Montreal, Quebec, H3A 2B4, Canada
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116
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Paul S, Michiels T. Cardiovirus leader proteins are functionally interchangeable and have evolved to adapt to virus replication fitness. J Gen Virol 2006; 87:1237-1246. [PMID: 16603526 DOI: 10.1099/vir.0.81642-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The leader (L) proteins encoded by picornaviruses of the genus Cardiovirus [Theiler's murine encephalomyelitis virus (TMEV) and Encephalomyocarditis virus (EMCV)] are small proteins thought to exert important functions in virus-host interactions. The L protein of persistent TMEV strains was shown to be dispensable for virus replication in vitro, but crucial for long-term persistence of the virus in the central nervous system of the mouse. The phenotype of chimeric viruses generated by exchanging the L-coding regions was analysed and it was shown that the L proteins of neurovirulent and persistent TMEV strains are functionally interchangeable in vitro and in vivo, despite the fact that L is the second most divergent protein encoded by these viruses after the L* protein. The L protein encoded by EMCV and Mengo virus (an EMCV strain) shares about 35 % amino acid identity with that of TMEV. It differs from the latter by lacking a serine/threonine-rich C-terminal domain and by carrying phosphorylated residues not conserved in the TMEV L protein. Our data show that, in spite of these differences, the L protein of Mengo virus shares, with that of TMEV, the ability to inhibit the transcription of type I interferon, cytokine and chemokine genes and to interfere with nucleocytoplasmic trafficking of host-cell proteins. Interestingly, analysis of viral RNA replication of the recombinant viruses raised the hypothesis that L proteins of TMEV and EMCV diverged during evolution to adapt to the different replication fitness of these viruses.
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Affiliation(s)
- Sophie Paul
- Université catholique de Louvain, Christian de Duve Institute of Cellular Pathology, Microbial Pathogenesis Unit, MIPA-VIRO 74-49, 74 avenue Hippocrate, B-1200 Brussels, Belgium
| | - Thomas Michiels
- Université catholique de Louvain, Christian de Duve Institute of Cellular Pathology, Microbial Pathogenesis Unit, MIPA-VIRO 74-49, 74 avenue Hippocrate, B-1200 Brussels, Belgium
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Delhaye S, Paul S, Blakqori G, Minet M, Weber F, Staeheli P, Michiels T. Neurons produce type I interferon during viral encephalitis. Proc Natl Acad Sci U S A 2006; 103:7835-40. [PMID: 16682623 PMCID: PMC1458506 DOI: 10.1073/pnas.0602460103] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Type I interferons, also referred to as IFN-alpha/beta, form the first line of defense against viral infections. Major IFN-alpha/beta producers in the periphery are the plasmacytoid dendritic cells (pDCs). Constitutive expression of the IFN regulatory factor (IRF)-7 enables pDCs to rapidly synthesize large amounts of IFN-alpha/beta after viral infection. In the central nervous system (CNS), pDCs are considered to be absent from the parenchyma, and little is known about the cells producing IFN-alpha/beta. The study presented here aimed to identify the cells producing IFN-alpha/beta in the CNS in vivo after infection by neurotropic viruses such as Theiler's virus and La Crosse virus. No cells with high constitutive expression of IRF-7 were detected in the CNS of uninfected mice, suggesting the absence of cells equivalent to pDCs. Upon viral infection, IFN-beta and some subtypes of IFN-alpha, but not IFN-epsilon or IFN-kappa, were transcriptionally up-regulated. IFN-alpha/beta was predominantly produced by scattered parenchymal cells and much less by cells of inflammatory foci. Interestingly, in addition to some macrophages and ependymal cells, neurons turned out to be important producers of both IFN-alpha and IFN-beta. However, only 3% of the infected neurons produced IFN-alpha/beta, suggesting that some restriction to IFN-alpha/beta production existed in these cells. All CNS cell types analyzed, including neurons, were able to respond to type I IFN by producing Mx or IRF-7. Our data show that, in vivo, neurons take an active part to the antiviral defense by being both IFN-alpha/beta producers and responders.
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Affiliation(s)
- Sophie Delhaye
- *Microbial Pathogenesis Unit, Université Catholique de Louvain and Christian de Duve Institute of Cellular Pathology, MIPA-VIRO 74–49, 74, Avenue Hippocrate, B-1200 Brussels, Belgium; and
| | - Sophie Paul
- *Microbial Pathogenesis Unit, Université Catholique de Louvain and Christian de Duve Institute of Cellular Pathology, MIPA-VIRO 74–49, 74, Avenue Hippocrate, B-1200 Brussels, Belgium; and
| | - Gjon Blakqori
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany
| | - Muriel Minet
- *Microbial Pathogenesis Unit, Université Catholique de Louvain and Christian de Duve Institute of Cellular Pathology, MIPA-VIRO 74–49, 74, Avenue Hippocrate, B-1200 Brussels, Belgium; and
| | - Friedemann Weber
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany
| | - Peter Staeheli
- Department of Virology, University of Freiburg, Hermann-Herder-Strasse 11, D-79104 Freiburg, Germany
| | - Thomas Michiels
- *Microbial Pathogenesis Unit, Université Catholique de Louvain and Christian de Duve Institute of Cellular Pathology, MIPA-VIRO 74–49, 74, Avenue Hippocrate, B-1200 Brussels, Belgium; and
- To whom correspondence should be addressed. E-mail:
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