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Hülskötter K, Lühder F, Flügel A, Herder V, Baumgärtner W. Tamoxifen Application Is Associated with Transiently Increased Loss of Hippocampal Neurons following Virus Infection. Int J Mol Sci 2021; 22:8486. [PMID: 34445189 PMCID: PMC8395206 DOI: 10.3390/ijms22168486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/27/2021] [Accepted: 08/04/2021] [Indexed: 11/27/2022] Open
Abstract
Tamoxifen is frequently used in murine knockout systems with CreER/LoxP. Besides possible neuroprotective effects, tamoxifen is described as having a negative impact on adult neurogenesis. The present study investigated the effect of a high-dose tamoxifen application on Theiler's murine encephalomyelitis virus (TMEV)-induced hippocampal damage. Two weeks after TMEV infection, 42% of the untreated TMEV-infected mice were affected by marked inflammation with neuronal loss, whereas 58% exhibited minor inflammation without neuronal loss. Irrespective of the presence of neuronal loss, untreated mice lacked TMEV antigen expression within the hippocampus at 14 days post-infection (dpi). Interestingly, tamoxifen application 0, 2 and 4, or 5, 7 and 9 dpi decelerated virus elimination and markedly increased neuronal loss to 94%, associated with increased reactive astrogliosis at 14 dpi. T cell infiltration, microgliosis and expression of water channels were similar within the inflammatory lesions, regardless of tamoxifen application. Applied at 0, 2 and 4 dpi, tamoxifen had a negative impact on the number of doublecortin (DCX)-positive cells within the dentate gyrus (DG) at 14 dpi, without a long-lasting effect on neuronal loss at 147 dpi. Thus, tamoxifen application during a TMEV infection is associated with transiently increased neuronal loss in the hippocampus, increased reactive astrogliosis and decreased neurogenesis in the DG.
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Affiliation(s)
- Kirsten Hülskötter
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany; (K.H.); (V.H.)
- Center for Systems Neuroscience, 30559 Hannover, Germany;
| | - Fred Lühder
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, 37075 Göttingen, Germany;
| | - Alexander Flügel
- Center for Systems Neuroscience, 30559 Hannover, Germany;
- Institute for Neuroimmunology and Multiple Sclerosis Research, University Medical Center Göttingen, 37075 Göttingen, Germany;
| | - Vanessa Herder
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany; (K.H.); (V.H.)
- Center for Systems Neuroscience, 30559 Hannover, Germany;
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Foundation, 30559 Hannover, Germany; (K.H.); (V.H.)
- Center for Systems Neuroscience, 30559 Hannover, Germany;
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Omura S, Sato F, Park AM, Fujita M, Khadka S, Nakamura Y, Katsuki A, Nishio K, Gavins FNE, Tsunoda I. Bioinformatics Analysis of Gut Microbiota and CNS Transcriptome in Virus-Induced Acute Myelitis and Chronic Inflammatory Demyelination; Potential Association of Distinct Bacteria With CNS IgA Upregulation. Front Immunol 2020; 11:1138. [PMID: 32733435 PMCID: PMC7358278 DOI: 10.3389/fimmu.2020.01138] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/11/2020] [Indexed: 02/05/2023] Open
Abstract
Virus infections have been associated with acute and chronic inflammatory central nervous system (CNS) diseases, e.g., acute flaccid myelitis (AFM) and multiple sclerosis (MS), where animal models support the pathogenic roles of viruses. In the spinal cord, Theiler's murine encephalomyelitis virus (TMEV) induces an AFM-like disease with gray matter inflammation during the acute phase, 1 week post infection (p.i.), and an MS-like disease with white matter inflammation during the chronic phase, 1 month p.i. Although gut microbiota has been proposed to affect immune responses contributing to pathological conditions in remote organs, including the brain pathophysiology, its precise role in neuroinflammatory diseases is unclear. We infected SJL/J mice with TMEV; harvested feces and spinal cords on days 4 (before onset), 7 (acute phase), and 35 (chronic phase) p.i.; and examined fecal microbiota by 16S rRNA sequencing and CNS transcriptome by RNA sequencing. Although TMEV infection neither decreased microbial diversity nor changed overall microbiome patterns, it increased abundance of individual bacterial genera Marvinbryantia on days 7 and 35 p.i. and Coprococcus on day 35 p.i., whose pattern-matching with CNS transcriptome showed strong correlations: Marvinbryantia with eight T-cell receptor (TCR) genes on day 7 and with seven immunoglobulin (Ig) genes on day 35 p.i.; and Coprococcus with gene expressions of not only TCRs and IgG/IgA, but also major histocompatibility complex (MHC) and complements. The high gene expression of IgA, a component of mucosal immunity, in the CNS was unexpected. However, we observed substantial IgA positive cells and deposition in the CNS, as well as a strong correlation between CNS IgA gene expression and serum anti-TMEV IgA titers. Here, changes in a small number of distinct gut bacteria, but not overall gut microbiota, could affect acute and chronic immune responses, causing AFM- and MS-like lesions in the CNS. Alternatively, activated immune responses would alter the composition of gut microbiota.
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Affiliation(s)
- Seiichi Omura
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Fumitaka Sato
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
| | - Ah-Mee Park
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Mitsugu Fujita
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Sundar Khadka
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Yumina Nakamura
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Aoshi Katsuki
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Kazuto Nishio
- Department of Genome Biology, Kindai University Faculty of Medicine, Osaka, Japan
| | - Felicity N. E. Gavins
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
- Department of Biosciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Ikuo Tsunoda
- Department of Microbiology, Kindai University Faculty of Medicine, Osaka, Japan
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, United States
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Mine K, Nagafuchi S, Hatano S, Tanaka K, Mori H, Takahashi H, Anzai K, Yoshikai Y. Impaired upregulation of Stat2 gene restrictive to pancreatic β-cells is responsible for virus-induced diabetes in DBA/2 mice. Biochem Biophys Res Commun 2020; 521:853-860. [PMID: 31708097 DOI: 10.1016/j.bbrc.2019.10.193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 10/29/2019] [Indexed: 12/16/2022]
Abstract
Viral infection is a putative causal factor for the development of type 1 diabetes, but the exact pathogenic mechanism of virus-induced diabetes (VID) remains unclear. Here, to identify the critical factors that regulate VID, we analyzed encephalomyocarditis D (EMC-D) VID-sensitive DBA/2 mice in comparison with resistant B6 mice. EMC-D virus-induced cell death occurred more frequently in DBA/2 β-cells than in B6 β-cells with 100U/ml IFN-β priming in vitro. We therefore purified β-cells using flow cytometry from mice two days after EMC-D virus infection and subjected them to microarray analysis. As a results, innate immune response pathway was found to be enriched in B6 β-cells. The signal transducer and activator of transcription 2 (Stat2) gene interacted with genes in the pathway. Stat2 gene expression levels were lower in DBA/2 mice than in B6 mice, restrictive to β-cells. Moreover, administration of IFN-β failed to upregulate Stat2 gene in DBA/2 β-cells than in those of B6 in vivo. The viral titer significantly increased only in the DBA/2 pancreas. Thus, these provided data suggest that impaired upregulation of Stat2 gene restrictive to β-cells at the early stage of infection is responsible for VID development in DBA/2 mice.
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Affiliation(s)
- Keiichiro Mine
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan; Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan.
| | - Seiho Nagafuchi
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan.
| | - Shinya Hatano
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Kenichi Tanaka
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Hitoe Mori
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Hirokazu Takahashi
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Keizo Anzai
- Division of Metabolism and Endocrinology, Department of Internal Medicine, Faculty of Medicine, Saga University, 5-1-1, Nabeshima, Saga, 849-8501, Japan
| | - Yasunobu Yoshikai
- Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
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Allnoch L, Baumgärtner W, Hansmann F. Impact of Astrocyte Depletion upon Inflammation and Demyelination in a Murine Animal Model of Multiple Sclerosis. Int J Mol Sci 2019; 20:ijms20163922. [PMID: 31409036 PMCID: PMC6719128 DOI: 10.3390/ijms20163922] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 08/07/2019] [Accepted: 08/10/2019] [Indexed: 12/17/2022] Open
Abstract
Astrocytes play a key role in demyelinating diseases, like multiple sclerosis (MS), although many of their functions remain unknown. The aim of this study was to investigate the impact of astrocyte depletion upon de- and remyelination, inflammation, axonal damage, and virus distribution in Theiler`s murine encephalomyelitis (TME). Groups of two to six glial fibrillary acidic protein (GFAP)-thymidine-kinase transgenic SJL mice and SJL wildtype mice were infected with TME virus (TMEV) or mock (vehicle only). Astrocyte depletion was induced by the intraperitoneal administration of ganciclovir during the early and late phase of TME. The animals were clinically investigated while using a scoring system and a rotarod performance test. Necropsies were performed at 46 and 77 days post infection. Cervical and thoracic spinal cord segments were investigated using hematoxylin and eosin (H&E), luxol fast blue-cresyl violet (LFB), immunohistochemistry targeting Amigo2, aquaporin 4, CD3, CD34, GFAP, ionized calcium-binding adapter molecule 1 (Iba1), myelin basic protein (MBP), non-phosphorylated neurofilaments (np-NF), periaxin, S100A10, TMEV, and immunoelectron microscopy. The astrocyte depleted mice showed a deterioration of clinical signs, a downregulation and disorganization of aquaporin 4 in perivascular astrocytes accompanied by vascular leakage. Furthermore, astrocyte depleted mice showed reduced inflammation and lower numbers of TMEV positive cells in the spinal cord. The present study indicates that astrocyte depletion in virus triggered CNS diseases contributes to a deterioration of clinical signs that are mediated by a dysfunction of perivascular astrocytes.
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Affiliation(s)
- Lisa Allnoch
- Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany.
- Center for Systems Neuroscience, 30559 Hannover, Germany.
| | - Florian Hansmann
- Department of Pathology, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Center for Systems Neuroscience, 30559 Hannover, Germany
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Bijalwan M, Young CR, Tingling J, Zhou XJ, Rimmelin AR, Leibowitz JL, Welsh CJ. Characterization of Plaque-Sized Variants of Daniel's (DA) Strain in Theiler's Virus-Induced Epilepsy. Sci Rep 2019; 9:3444. [PMID: 30837498 PMCID: PMC6401140 DOI: 10.1038/s41598-019-38967-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 01/09/2019] [Indexed: 12/20/2022] Open
Abstract
Epilepsy is a complex neurological disease characterized by recurrent seizures. Patients with viral encephalitis have a 16-fold increased risk of developing epilepsy, and this risk can persist for about 15 years after the occurrence of initial viral infection. Theiler's murine encephalomyelitis virus (TMEV) infection induces a well-characterized experimental model of epilepsy in C57BL/6 mice. In response to intracerebral (I.C.) injection of Daniel's (DA) strain of TMEV, there is vigorous immune response, which is detrimental to neurons and contributes to acute seizures, rendering mice susceptible to epilepsy. A comparative in vivo challenge study with either one of the two variants of the DA strain, small (DA-DS) or large (DA-CL) plaque forming variants, revealed differences in the diseases they induced in C57BL/6 mice. Compared to DA-CL-, DA-DS-infected mice exhibited significantly more seizures, higher clinical scores, neuroinflammation, and neuronal damage (mainly in the CA1-CA2 regions of hippocampus). Moreover, the brains of DA-DS infected mice contained approximately five-fold higher virus than those of DA-CL infected mice. A sequence comparison of the DA-CL and DA-DS genome sequences showed mutations in the leader (L) and L* proteins of DA-CL variant, which may be the cause of attenuating phenotype of DA-CL variant in the C57BL/6 mouse model of epilepsy.
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Affiliation(s)
- M Bijalwan
- Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - C R Young
- Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - J Tingling
- Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, Texas, USA
| | - X J Zhou
- Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, Texas, USA
- College Station High School, Texas A&M Health Science Center, College Station, Texas, USA
| | - A R Rimmelin
- Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA
| | - J L Leibowitz
- Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, College Station, Texas, USA
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, USA
| | - C J Welsh
- Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, College Station, Texas, USA.
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, Texas, USA.
- Women's Health in Neuroscience Program, Texas A&M Health Science Center, College Station, Texas, USA.
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6
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Moyano AL, Steplowski J, Wang H, Son KN, Rapolti DI, Marshall J, Elackattu V, Marshall MS, Hebert AK, Reiter CR, Ulloa V, Pituch KC, Givogri MI, Lu QR, Lipton HL, Bongarzone ER. microRNA-219 Reduces Viral Load and Pathologic Changes in Theiler's Virus-Induced Demyelinating Disease. Mol Ther 2018; 26:730-743. [PMID: 29433936 DOI: 10.1016/j.ymthe.2018.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 01/06/2018] [Accepted: 01/11/2018] [Indexed: 01/10/2023] Open
Abstract
Analysis of microRNA (miR) expression in the central nervous system white matter of SJL mice infected with the BeAn strain of Theiler's murine encephalomyelitis virus (TMEV) revealed a significant reduction of miR-219, a critical regulator of myelin assembly and repair. Restoration of miR-219 expression by intranasal administration of a synthetic miR-219 mimic before disease onset ameliorates clinical disease, reduces neurogliosis, and partially recovers motor and sensorimotor function by negatively regulating proinflammatory cytokines and virus RNA replication. Moreover, RNA sequencing of host lesions showed that miR-219 significantly downregulated two genes essential for the biosynthetic cholesterol pathway, Cyp51 (lanosterol 14-α-demethylase) and Srebf1 (sterol regulatory element-binding protein-1), and reduced cholesterol biosynthesis in infected mice and rat CG-4 glial precursor cells in culture. The change in cholesterol biosynthesis had both anti-inflammatory and anti-viral effects. Because RNA viruses hijack endoplasmic reticulum double-layered membranes to provide a platform for RNA virus replication and are dependent on endogenous pools of cholesterol, miR-219 interference with cholesterol biosynthesis interfered virus RNA replication. These findings demonstrate that miR-219 inhibits TMEV-induced demyelinating disease through its anti-inflammatory and anti-viral properties.
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Affiliation(s)
- Ana Lis Moyano
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA.
| | - Jeffrey Steplowski
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Haibo Wang
- Department of Pediatrics, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Kyung-No Son
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Diana I Rapolti
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Jeffrey Marshall
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Vince Elackattu
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Michael S Marshall
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Amy K Hebert
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Cory R Reiter
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Viviana Ulloa
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Katarzyna C Pituch
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Maria I Givogri
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Q Richard Lu
- Department of Pediatrics, Division of Experimental Hematology and Cancer Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Howard L Lipton
- Department of Microbiology and Immunology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Ernesto R Bongarzone
- Department of Anatomy and Cell Biology, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
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7
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Kim SJ, Jin YH, Kim BS. Prostaglandin E2 produced following infection with Theiler's virus promotes the pathogenesis of demyelinating disease. PLoS One 2017; 12:e0176406. [PMID: 28445497 PMCID: PMC5406002 DOI: 10.1371/journal.pone.0176406] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 04/09/2017] [Indexed: 12/11/2022] Open
Abstract
Infection of various cells with Theiler’s murine encephalomyelitis virus (TMEV) activates the TLR- and melanoma differentiation-associated gene 5 (MDA5)-dependent pathways, resulting in the production of IL-1β via the activation of caspase-1 upon assembly of the node-like receptor protein 3 (NLRP3) inflammasome. The role of IL-1β in the pathogenesis of TMEV-induced demyelinating disease was previously investigated. However, the signaling effects of prostaglandin E2 (PGE2) downstream of the NLRP3 inflammasome on the immune responses to viral determinants and the pathogenesis of demyelinating disease are unknown. In this study, we investigated the levels of intermediate molecules leading to PGE2 signaling and the effects of blocking PGE2 signaling on the immune response to TMEV infection, viral persistence and the development of demyelinating disease. We demonstrate here that TMEV infection activates the NLRP3 inflammasome and PGE2 signaling much more vigorously in dendritic cells (DCs) and CD11b+ cells from susceptible SJL mice than in cells from resistant B6 mice. Inhibition of virus-induced PGE2 signaling using AH23848 resulted in decreased pathogenesis of demyelinating disease and viral loads in the central nervous system (CNS). In addition, AH23848 treatment caused the elevation of protective early IFN-γ-producing CD4+ and CD8+ T cell responses. Because the levels of IFN-β were lower in AH23848-treated mice but the level of IL-6 was similar, over-production of pathogenic IFN-β was modulated and the generation of IFN-γ-producing T cell responses was enhanced by the inhibition of PGE2 signaling. These results strongly suggest that excessive activation of the NLRP3 inflammasome and downstream PGE2 signaling contribute to the pathogenesis of TMEV-induced demyelinating disease.
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Affiliation(s)
- Seung Jae Kim
- Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois
| | - Young-Hee Jin
- Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois
| | - Byung S. Kim
- Department of Microbiology-Immunology, Northwestern University Medical School, Chicago, Illinois
- * E-mail:
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Yama S, Nishioka W, Hirokami Y, Setoguchi R, Takeyama N, Saeki K, Matsumoto Y, Hayashi T, Doi K, Onodera T. Effects of Tacrolimus (FK506) on Encephalomyocarditic Virus-Induced Diabetes in Mice. Microbiol Immunol 2013; 48:7-13. [PMID: 14734853 DOI: 10.1111/j.1348-0421.2004.tb03482.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of tacrolimus on insulin-dependent diabetes mellitus (IDDM) induced by the D-variant of encephalomyocarditis virus (D-EMCV) have been investigated. Male BALB/c mice were treated with tacrolimus before viral inoculation, and then were inoculated with 10 plaque forming units (PFU) of DEMCV. The mice continued to be treated with tacrolimus until the animals were sacrificed. D-EMCV-infected mice, which were treated with saline as controls, showed abnormal glucose tolerance test (GTT) values, whereas all infected mice with tacrolimus pretreatment were normal on 7 days-post inoculation (DPI). Histological observations revealed that non-treated tacrolimus D-EMCV-infected mice and which developed diabetes showed severe insulitis in their islets of Langerhans. On the other hand, D-EMCV-infected mice treated with tacrolimus were normal. In D-EMCV-infected mice, viruses in the pancreata were detected at the same level regardless of treatment with tacrolimus or saline. Expressions of TNF-alpha and IFN-gamma mRNA in spleens of tacrolimus-treated D-EMCV-infected mice were lower than that of non-treated tacrolimus DEMCV-infected mice on 7 DPI. The results suggest that tacrolimus suppresses expressions of TNF-alpha and IFN-gamma mRNAs to prevent the onset of D-EMCV-induced IDDM.
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Affiliation(s)
- Sachiko Yama
- Faculty of Agriculture, The University of Tokyo, Japan
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9
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Kounoue E, Izumi KI, Ogawa S, Kondo S, Katsuta H, Akashi T, Niho Y, Harada M, Tamiya S, Kurisaki H, Nagafuchi S. The significance of T cells, B cells, antibodies and macrophages against encephalomyocarditis (EMC)-D virus-induced diabetes in mice. Arch Virol 2008; 153:1223-31. [PMID: 18500429 DOI: 10.1007/s00705-008-0106-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 04/11/2008] [Indexed: 11/26/2022]
Abstract
In order to clarify the significance of protective mechanisms against encephalomyocarditis (EMC) virus-induced diabetes in mice, we studied the relative importance of T cells, B cells, antibodies and macrophages in the prevention of virus-induced diabetes. Neither T cell-deficient athymic nude mice nor B cell-deficient microMT/microMT mice showed an enhanced clinical course of EMC-D virus-induced diabetes, indicating that neither T cells nor B cells played a major role in the protection against EMC-D-virus-induced diabetes. Transfer of a large amount of antiserum to EMC-D-virus-infected mice protected the development of diabetes only when transferred within 36 h of infection, the timing of which was earlier than that for the production of natural neutralizing antibodied. Since pretreatment of mice with the macrophage-activating immunopotentiator Corynebacterium parvum (CP) completely prevented the development of diabetes, we studied the clinical outcome of EMC-D-virus-infected mice pretreated with CP. Mice treated with CP showed reduced proliferation of EMC-D virus in the affected organs, including the pancreas, while the levels of development of neutralizing antibody and serum interferon were not enhanced compared with the controls. Finally, we studied the macrophages derived from mice pretreated with CP and found that they inhibited the growth of EMC-D virus in vitro more than those derived from non-treated and thioglycolate-treated mice. Taken together, it can be suggested that neither T cells nor B cells, which have to do with adaptive immunity, play a significant role in the pathogenesis of EMC-D-virus-induced diabetes, while innate immunity, which is dependent on activated macrophages, contributes to in vivo resistance against EMC-D-virus-induced diabetes.
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Affiliation(s)
- Etsushi Kounoue
- Department of Medicine and Biosystemic Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, 812-8582, Japan
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10
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Takahashi T, Yu F, Saegusa S, Sumino H, Nakahashi T, Iwai K, Morimoto S, Kurabayashi M, Kanda T. Impaired expression of cardiac adiponectin in leptin-deficient mice with viral myocarditis. Int Heart J 2007; 47:107-23. [PMID: 16479046 DOI: 10.1536/ihj.47.107] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A mouse model of encephalomyocarditis (EMC) virus-induced myocarditis was used to investigate the expression of adiponectin in damaged cardiomyocytes. We intraperitoneally injected EMC virus into leptin-deficient ob/ob (OB) mice and wild-type (WT) mice. OB mice were divided into two subgroups consisting of mice with no intervention and mice receiving leptin replacement starting simultaneously with viral inoculation. We determined differences in heart weight, cardiac histological score, numbers of infiltrating and apoptotic cells in the myocardium, expression levels of adiponectin and TNF-alpha mRNA in the heart, adiponectin immunoreactivity in myocytes, adiponectin and TNF-alpha concentrations in the heart, and immunoreactivity of adiponectin receptors in myocytes between OB mice and WT mice. There was significantly decreased adiponectin mRNA expression, immunoreactivity, and protein level in the heart, and reduced immunoreactivity of adiponectin receptor 1 in myocytes from OB mice on days 4 and 8 after viral inoculation as compared with those in WT mice, together with increased cardiac weight, severe inflammatory myocardial damage, and increased levels of cardiac TNF-alpha mRNA and protein. Replacement of leptin in OB mice inhibited the development of severe myocarditis through augmentation of adiponectin mRNA, immunoreactivity, and protein level, increased adiponectin receptor 1 immunoreactivity in myocytes, and suppressed levels of TNF-alpha mRNA and protein. These results suggest that impaired expression of cardiac adiponectin may contribute to the progression of viral myocarditis through enhanced expression of TNF-alpha under a leptin-deficient condition.
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Affiliation(s)
- Takashi Takahashi
- Department of General Medicine, Kanazawa Medical University, Ishikawa, Japan
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11
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Bennett JL, Elhofy A, Charo I, Miller SD, Dal Canto MC, Karpus WJ. CCR2 regulates development of Theiler's murine encephalomyelitis virus-induced demyelinating disease. Viral Immunol 2007; 20:19-33. [PMID: 17425418 DOI: 10.1089/vim.2006.0068] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease, a murine model for multiple sclerosis, involves recruitment of T cells and macrophages to the CNS after infection. We hypothesized that CCR2, the only known receptor for CCL2, would be required for TMEV-induced demyelinating disease development because of its role in macrophage recruitment. TMEV-infected SJL CCR2 knockout (KO) mice showed decreased long-term clinical disease severity and less demyelination compared with controls. Flow cytometric data indicated that macrophages (CD45(high) CD11b(+) ) in the CNS of TMEV-infected CCR2 KO mice were decreased compared with control mice throughout disease. CD4(+) and CD8(+) T cell percentages in the CNS of TMEV-infected control and CCR2 KO mice were similar over the course of disease. There were no apparent differences between CCR2 KO and control peripheral immune responses. The frequency of interferon-gamma-producing T cells in response to proteolipid protein 139-151 in the CNS was also similar during the autoimmunity stage of TMEV-induced demyelinating disease. These data suggest that CCR2 is important for development of clinical disease by regulating macrophage accumulation after TMEV infection.
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Affiliation(s)
- Jami L Bennett
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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13
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Abstract
During the last decades, the incidence of type 1 diabetes (T1D) has increased significantly, reaching percentages of 3% annually worldwide. This increase suggests that besides genetical factors environmental perturbations (including viral infections) are also involved in the pathogenesis of T1D. T1D has been associated with viral infections including enteroviruses, rubella, mumps, rotavirus, parvovirus and cytomegalovirus (CMV). Although correlations between clinical presentation with T1D and the occurrence of a viral infection that precedes the development of overt disease have been recognized, causalities between viruses and the diabetogenic process are still elusive and difficult to prove in humans. The use of experimental animal models is therefore indispensable, and indeed more insight in the mechanism by which viruses can modulate diabetogenesis has been provided by studies in rodent models for T1D such as the biobreeding (BB) rat, nonobese diabetic (NOD) mouse or specific transgenic mouse strains. Data from experimental animals as well as in vitro studies indicate that various viruses are clearly able to modulate the development of T1D via different mechanisms, including direct beta-cell lysis, bystander activation of autoreactive T cells, loss of regulatory T cells and molecular mimicry. Data obtained in rodents and in vitro systems have improved our insight in the possible role of viral infections in the pathogenesis of human T1D. Future studies will hopefully reveal which human viruses are causally involved in the induction of T1D and this knowledge may provide directions on how to deal with viral infections in diabetes-susceptible individuals in order to delay or even prevent the diabetogenic process.
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Affiliation(s)
- Nienke van der Werf
- Department of Cell Biology, Immunology Section, University Medical Center Groningen, University of Groningen, The Netherlands
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14
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Kanda T, Saegusa S, Takahashi T, Sumino H, Morimoto S, Nakahashi T, Iwai K, Matsumoto M. Reduced-energy diet improves survival of obese KKAy mice with viral myocarditis: induction of cardiac adiponectin expression. Int J Cardiol 2007; 119:310-8. [PMID: 17275107 DOI: 10.1016/j.ijcard.2006.07.181] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 07/24/2006] [Accepted: 07/29/2006] [Indexed: 11/19/2022]
Abstract
Obesity is an important risk factor for heart disease. Whether weight loss affects the severity of heart failure induced by viral myocarditis is a matter of debate. We hypothesized that weight loss could improve cardiac dysfunction by inducing cardiac expression of a cardioprotective cytokine, adiponectin. We examined the relationship between weight loss by food restriction and heart failure due to viral myocarditis in obese KKAy mice. We intraperitoneally injected encephalomyocarditis virus (500 plaque-forming units/mouse) into KKAy mice fed ad libitum as a control (CF) or 60% restriction of that eaten by ad libitum (RF). The 14-day survival rate was 0% in FF, whereas it was 23% in RF (P<0.01). Heart weight/body weight ratio in RF was lower than that in FF on day 5 after viral inoculation (P<0.05). Histological scores for myocardial necrosis and inflammation on day 5 were significantly lower in RF than in FF (P<0.05). Circulating adiponectin level on day 0 was significantly elevated in RF compared with that in FF (32+9 vs. 22+2 microg/mL, P<0.05). Comparative expression of cardiac adiponectin mRNA in RF was significantly higher than that in FF (5.1+0.3 vs. 1+0.2, P<0.05). Cardiac tumor necrosis factor-alpha (TNF-alpha) mRNA in RF was significantly decreased compared with that in FF on day 5 (P<0.05). Cardiac expression of nuclear factor kappa B was reduced and that of peroxisome proliferator-activated receptor gamma mRNA was increased in RF in comparison with FF on day 0. Cardiac adiponectin mRNA was negatively correlated with cardiac TNF-alpha mRNA (r=-0.555; P=0.0097). Weight loss improved the survival and myocardial damage in obese mice with viral myocarditis, with cardiac induction of adiponectin. The induction of adiponectin might provide benefit through a cardioprotective effect against acute heart failure due to viral myocarditis in obese subjects.
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Affiliation(s)
- Tsugiyasu Kanda
- Department of General Medicine, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku-gun, Ishikawa 920-0293, Japan.
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15
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Croxford J, Ercolini A, DeGutes M, Miller S. Structural requirements for initiation of cross-reactivity and CNS autoimmunity with a PLP139-151 mimic peptide derived from murine hepatitis virus. Eur J Immunol 2006; 36:2671-80. [PMID: 16981179 PMCID: PMC7163677 DOI: 10.1002/eji.200635876] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
MS is an autoimmune CNS demyelinating disease in which infection appears to be an important pathogenic factor. Molecular mimicry, the cross‐activation of autoreactive T cells by mimic peptides from infectious agents, is a possible explanation for infection‐induced autoimmunity. Infection of mice with a non‐pathogenic strain of Theiler's murine encephalomyelitis virus (TMEV) engineered to express an epitope from Haemophilus influenzae (HI) sharing 6/13 amino acids with the dominant proteolipid protein (PLP) epitope, PLP139–151, can induce CNS autoimmune disease. Here we demonstrate that another PLP139–151 mimic sequence derived from murine hepatitis virus (MHV) which shares only 3/13 amino acids with PLP139–151 can also induce CNS autoimmune disease, but only when delivered by genetically engineered TMEV, not by immunization with the MHV peptide. Further, we demonstrate the importance of proline at the secondary MHC class II contact residue for effective cross‐reactivity, as addition of this amino acid to the native MHV sequence increases its ability to cross‐activate PLP139–151‐specific autoreactive T cells, while substitution of proline in the HI mimic peptide has the opposite effect. This study describes a structural requirement for potential PLP139–151 mimic peptides, and provides further evidence for infection‐induced molecular mimicry in the pathogenesis of autoimmune disease.
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Affiliation(s)
- J. Ludovic Croxford
- Department of Microbiology‐Immunology and the Interdepartmental Immunobiology Center, Northwestern University Feinberg School of Medicine, Chicago, USA
- Department of Immunology, National Institute of Neuroscience, National Centre of Neurology & Psychiatry, 4‐1‐1 Ogawahigashi, Kodaira, Tokyo 187–8502, Japan
| | - Anne M. Ercolini
- Department of Microbiology‐Immunology and the Interdepartmental Immunobiology Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Mathew DeGutes
- Department of Microbiology‐Immunology and the Interdepartmental Immunobiology Center, Northwestern University Feinberg School of Medicine, Chicago, USA
| | - Stephen D. Miller
- Department of Microbiology‐Immunology and the Interdepartmental Immunobiology Center, Northwestern University Feinberg School of Medicine, Chicago, USA
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16
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Denis P, Liebig HD, Nowotny N, Billinis C, Papadopoulos O, O'Hara RS, Knowles NJ, Koenen F. Genetic variability of encephalomyocarditis virus (EMCV) isolates. Vet Microbiol 2006; 113:1-12. [PMID: 16406410 DOI: 10.1016/j.vetmic.2005.10.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2004] [Revised: 10/05/2005] [Accepted: 10/13/2005] [Indexed: 11/20/2022]
Abstract
In order to evaluate the variability of encephalomyocarditis virus (EMCV), field isolates originating from different European regions and inducing different clinical pictures in pigs have been molecularly characterised. The regions targeted were the poly(C) tract, a part of the 5'-UTR (360 nucleotides), the Leader gene (201 nucleotides), the complete capsid coding region (2502 nucleotides), the 2A gene (403 nucleotides), the end of the 3D polymerase gene (305 nucleotides) and the 3'-UTR (123 nucleotides). Analyses have also been performed on a virulent field isolate, which had been subjected to serial passages in vivo and in vitro resulting, in the case of the in vitro passaged virus, in attenuation, as demonstrated by animal experiments. The present study shows that different clinical pictures, such as acute fatal myocarditis or reproductive failure, may not only be caused by EMCV isolates which are genetically diverse but also by the same isolate. Thus no correlation could be demonstrated between genotype and clinical disease. However, the European isolate which showed the highest genetic divergence also gave rise to a more complex clinical picture. Despite EMCV having been isolated from cases of acute fatal myocarditis in pigs in certain areas of the world for many years, clinical disease, including a variety of clinical pictures and pathogenicity, has only been recognised in Europe since 1986 and thus it can be considered an emerging disease in this region. These findings, associated with the reported phenotype changes of the virus under environmental changes (passages), along with its wide distribution among vertebrate species (including higher primates), shows the validity of considering EMCV as a potential pathogen for recipients in xenotransplantation.
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Affiliation(s)
- P Denis
- Veterinary and Agrochemical Research Center, Groeselenberg 99, 1180 Brussels, Belgium
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17
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Abstract
Theiler's virus causes a persistent and demyelinating infection of the central nervous system of the mouse, which is one of the best animal models to study multiple sclerosis. This review focuses on the mechanism of persistence. The virus infects neurons for a few weeks and then shifts to white matter, where it persists in glial cells and macrophages. Oligodendrocytes are crucial host cells, as shown by the resistance to persistent infection of mice bearing myelin mutations. Two viral proteins, L and L*, contribute to persistence by interfering with host defenses. L, a small zinc-finger protein, restricts the production of interferon. L*, a unique example of a picornaviral protein translated from an overlapping open reading frame, facilitates the infection of macrophages. Susceptibility to persistent infection, which varies among inbred mouse strains, is multigenic. H2 class I genes have a major effect on susceptibility. Among several non-H2 susceptibility loci, Tmevp3 appears to regulate the expression of important cytokines.
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Affiliation(s)
- Michel Brahic
- Unité des Virus Lents, URA CNRS 1930, Institut Pasteur, 75724 Paris Cedex 15, France.
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18
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Denton PW, Tello CM, Melvold RW. CD8+ T cells reduce in vitro interferon-gamma production in Theiler's murine encephalomyelitis virus-induced demyelinating disease model. Mult Scler 2004; 10:370-5. [PMID: 15327031 DOI: 10.1191/1352458504ms1054oa] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
In the Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease model for multiple sclerosis, regulatory CD8+ T cells prevent demyelinating disease and reduce in vivo interferon (IFN)-gamma production by anti-TMEV CD4+ blast cells in BALB/c mice. We describe here that regulatory CD8+ T cells reduce in vitro IFN-gamma production by lymph node cells from both TMEV and fowl gamma globulin immunized mice without affecting interleukin (IL)-4, IL-10, tumour growth factor-beta or tumour necrosis factor-alpha production.
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Affiliation(s)
- Paul W Denton
- Department of Microbiology and Immunology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203-9037, USA
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19
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Abstract
Lymphotoxin (LT) and tumor necrosis factor (TNF) are important in immune system development and function. LT consists of soluble LT-alpha(3), which binds to TNF-R1 and TNF-R2, and membrane LT-alpha(1)beta(2), which binds to LT-beta-R. We investigated the role of LT and TNF in disease induced by Daniel's (DA) strain of Theiler's murine encephalomyelitis virus (TMEV) since the immune response is believed to be important in both resistance to DA infection as well as mediation of virus-induced demyelination. DA persisted and induced inflammatory demyelination in LT-alpha(-/-) (but not TNF(-/-)) weanling mice of a normally resistant haplotype (C57BL/6), suggesting that LT, but not TNF, is critical for resistance to DA infection. This activity of LT depends on membrane LT-alpha(1)beta(2) and not soluble LT-alpha(3), since DA virus persisted and induced inflammatory demyelination in LT-beta-R(-/-), but not TNF-R1(-/-) or TNF-R2(-/-), mice. The LT-alpha(-/-) and LT-beta-R(-/-) mice failed to mount a virus-specific cytotoxic T cell response. Treatment of weanling C57BL/6 mice with LT-beta-R-Ig, which blocks membrane LT activity, failed to increase susceptibility, suggesting that the LT effect is related to its action on immune system development which is fixed by 3 weeks of age. Our data suggest that membrane LT is important in resistance to DA infection (possibly through interference with CD8+ T cell development and function). There was relatively little demyelination associated with inflammation in LT-alpha(-/-) and LT-beta-R(-/-) mice compared to susceptible SJL mice, suggesting the possibility that LT plays a role in mediating demyelination.
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MESH Headings
- Animals
- Antibodies, Viral/blood
- Antigens, CD/genetics
- Antigens, CD/physiology
- Antigens, Viral/analysis
- Cardiovirus Infections/complications
- Cardiovirus Infections/immunology
- Demyelinating Diseases/etiology
- Demyelinating Diseases/immunology
- Enzyme-Linked Immunosorbent Assay
- Female
- Immunohistochemistry
- Killer Cells, Natural/immunology
- Killer Cells, Natural/physiology
- Lymphotoxin beta Receptor
- Lymphotoxin-alpha/genetics
- Lymphotoxin-alpha/physiology
- Lymphotoxin-beta
- Membrane Proteins/genetics
- Membrane Proteins/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/physiology
- Receptors, Tumor Necrosis Factor, Type I
- Receptors, Tumor Necrosis Factor, Type II
- Spinal Cord/immunology
- Spinal Cord/pathology
- Spinal Cord/virology
- T-Lymphocytes, Cytotoxic/immunology
- T-Lymphocytes, Cytotoxic/physiology
- Theilovirus/immunology
- Tumor Necrosis Factor-alpha/genetics
- Tumor Necrosis Factor-alpha/physiology
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Affiliation(s)
- Xiaoqi Lin
- Department of Neurology, University of Chicago, Chicago, IL 60637, USA
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20
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Croxford JL, Miller SD. Immunoregulation of a viral model of multiple sclerosis using the synthetic cannabinoid R+WIN55,212. J Clin Invest 2003; 111:1231-40. [PMID: 12697742 PMCID: PMC152941 DOI: 10.1172/jci17652] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Theiler murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD) is a mouse model of chronic-progressive multiple sclerosis (MS) characterized by Th1-mediated CNS demyelination and spastic hindlimb paralysis. Existing MS therapies reduce relapse rates in 30% of relapsing-remitting MS patients, but are ineffective in chronic-progressive disease, and their effects on disability progression are unclear. Experimental studies demonstrate cannabinoids are useful for symptomatic treatment of spasticity and tremor in chronic-relapsing experimental autoimmune encephalomyelitis. Cannabinoids, however, have reported immunosuppressive properties. We show that the cannabinoid receptor agonist, R+WIN55,212, ameliorates progression of clinical disease symptoms in mice with preexisting TMEV-IDD. Amelioration of clinical disease is associated with downregulation of both virus and myelin epitope-specific Th1 effector functions (delayed-type hypersensitivity and IFN-gamma production) and the inhibition of CNS mRNA expression coding for the proinflammatory cytokines, TNF-alpha, IL1-beta, and IL-6. Clinical trials investigating the therapeutic potential of cannabinoids for the symptomatic treatment of MS are ongoing, and this study demonstrates that they may also have potent immunoregulatory properties.
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Affiliation(s)
- J Ludovic Croxford
- Department of Microbiology-Immunology, Interdepartmental Immunobiology Center, Northwestern University Medical School, 303 E. Chicago Avenue, Chicago, IL 60611, USA
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21
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Abstract
Genes of the major histocompatibility complex (MHC) play a critical role in immune recognition, and many alleles confer susceptibility to infectious and autoimmune diseases. How these deleterious alleles persist in populations is controversial. One hypothesis postulates that MHC heterozygote superiority emerges over multiple infections because MHC-mediated resistance is generally dominant and many allele-specific susceptibilities to pathogens will be masked by the resistant allele in heterozygotes. We tested this hypothesis by using experimental coinfections with Salmonella enterica (serovar Typhimurium C5TS) and Theiler's murine encephalomyelitis virus (TMEV) in MHC-congenic mouse strains where one haplotype was resistant to Salmonella and the other was resistant to TMEV. MHC heterozygotes were superior to both homozygotes in 7 out of 8 comparisons (P = 0.0024), and the mean standardized pathogen load of heterozygotes was reduced by 41% over that of homozygotes (P = 0.01). In contrast, no heterozygote superiority was observed when the MHC haplotype combinations had similar susceptibility profiles to the two pathogens. This is the first experimental evidence for MHC heterozygote superiority against multiple pathogens, a mechanism that would contribute to the evolution of MHC diversity and explain the persistence of alleles conferring susceptibility to disease.
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Affiliation(s)
- Erin E McClelland
- Biology Department, University of Utah, Salt Lake City, UT 84112, USA
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22
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Nishio R, Shioi T, Sasayama S, Matsumori A. Carvedilol increases the production of interleukin-12 and interferon-gamma and improves the survival of mice infected with the encephalomyocarditis virus. J Am Coll Cardiol 2003; 41:340-5. [PMID: 12535832 DOI: 10.1016/s0735-1097(02)02711-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVES This study was designed to examine the effects of carvedilol in a murine model of viral myocarditis induced by encephalomyocarditis virus (EMCV) infection. BACKGROUND Cytokines play an important role in the pathophysiology of viral myocarditis. Catecholamines influence the production of cytokines via beta-adrenergic receptors, suggesting that beta-adrenergic blockers could modulate the production of cytokines and exert a therapeutic effect in viral myocarditis by blocking the beta-stimulating action of endogenous catecholamines. In clinical trials, the third-generation, nonselective beta-blocker carvedilol was the first among several beta-blockers to reduce mortality in heart failure. However, the effects of carvedilol in acute viral myocarditis and on cytokine production are unknown. METHODS This study compared the effects of carvedilol, the selective beta(1)-blocker metoprolol, and the nonselective beta-blocker propranolol in a murine model of viral myocarditis induced by EMCV. RESULTS Carvedilol improved the 14-day survival of the animals, attenuated myocardial lesions on day 7, and increased myocardial levels of interleukin (IL)-12 and interferon (IFN)-gamma, whereas reducing myocardial virus replication. Propranolol also attenuated myocardial lesions, but to a lesser extent, and increased IL-12 and IFN-gamma levels. Metoprolol had no effect in this model. Encephalomyocarditis virus infection increased plasma catecholamine levels. CONCLUSIONS These results suggest that by blocking the beta(2)-stimulating effects of catecholamines, carvedilol exerts some of its beneficial effects by increasing the production of IL-12 and IFN-gamma. Carvedilol may be effective in patients with viral myocarditis by boosting IL-12 and IFN-gamma production.
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Affiliation(s)
- Ryosuke Nishio
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Japan
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23
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Abstract
It was previously demonstrated that administration of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME) aggravated viral myocarditis in mice. In the current study, the effects of l-arginine, a precursor of nitric oxide, on congestive heart failure (CHF) in myocarditis were evaluated. Dietary l-arginine and l-arginine plus l-NAME (l-arginine + l-NAME group) were administered to encephalomyocarditis virus-infected BALB/c mice over 4 weeks (experiment I) and to encephalomyocarditis virus-infected DBA/2 mice from the 4th through 12th weeks after the virus inoculation (experiment II). An infected control was prepared in each experiment. In experiment I, survival was higher in the l-arginine group compared with the other two groups, and cardiac damage was less, as was incidence of CHF. In addition, extravasated fibrin was less prominent in the l-arginine group. Plasma concentrations of l-arginine and nitric oxide were elevated in the l-arginine group. In experiment II, plasma cardiomyopathic lesions in the l-arginine group were less prominent and were associated with lower plasma catecholamine and lower myocardial collagen concentrations compared with the other two groups. l-arginine treatment may be effective in preventing the development of CHF in viral myocarditis by modifying postmyocarditic architectural remodeling.
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Affiliation(s)
- Yuji Hiraoka
- The Second Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan
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24
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Abstract
IFN-gamma is an anti-viral and immunomodulatory cytokine critical for resistance to multiple pathogens. Using mice with targeted disruption of the gene for IFN-gamma, we previously demonstrated that this cytokine is critical for resistance to viral persistence and demyelination in the Theiler's virus model of multiple sclerosis. During viral infections, IFN-gamma is produced by natural killer (NK) cells, CD4(+) and CD8(+) T cells; however, the proportions of lymphocyte subsets responding to virus infection influences the contributions to IFN-gamma-mediated protection. To determine the lymphocyte subsets that produce IFN-gamma to maintain resistance, we used adoptive transfer strategies to generate mice with lymphocyte-specific deficiencies in IFN-gamma-production. We demonstrate that IFN-gamma production by both CD4(+) and CD8(+) T cell subsets is critical for resistance to Theiler's murine encephalomyelitis virus (TMEV)-induced demyelination and neurological disease, and that CD4(+) T cells make a greater contribution to IFN-gamma-mediated protection. To determine the cellular targets of IFN-gamma-mediated responses, we used adoptive transfer studies and bone marrow chimerism to generate mice in which either hematopoietic or somatic cells lacked the ability to express IFN-gamma receptor. We demonstrate that IFN-gamma receptor must be present on central nervous system glia, but not bone marrow-derived lymphocytes, in order to maintain resistance to TMEV-induced demyelination.
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MESH Headings
- Animals
- Antigens, Viral/analysis
- Bone Marrow Transplantation
- CD4-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/immunology
- Cardiovirus Infections/complications
- Cardiovirus Infections/immunology
- Cardiovirus Infections/pathology
- Cardiovirus Infections/therapy
- Crosses, Genetic
- Demyelinating Diseases/etiology
- Demyelinating Diseases/immunology
- Demyelinating Diseases/pathology
- Demyelinating Diseases/therapy
- Disease Models, Animal
- Disease Susceptibility
- Immunotherapy, Adoptive
- Interferon-gamma/deficiency
- Interferon-gamma/genetics
- Interferon-gamma/physiology
- Lymphocyte Subsets/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Multiple Sclerosis
- Psychomotor Performance
- RNA, Viral/analysis
- Radiation Chimera
- Receptors, Interferon/deficiency
- Receptors, Interferon/genetics
- Receptors, Interferon/physiology
- Spinal Cord/pathology
- Theilovirus/immunology
- Theilovirus/physiology
- Interferon gamma Receptor
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Affiliation(s)
- Paul D. Murray
- Department of Immunology, Mayo Clinic and Foundation, Rochester, USA
| | - Dorian B. McGavern
- Department of Molecular Neuroscience, Mayo Clinic and Foundation, Rochester, USA
| | - Larry R. Pease
- Department of Immunology, Mayo Clinic and Foundation, Rochester, USA
| | - Moses Rodriguez
- Department of Immunology, Mayo Clinic and Foundation, Rochester, USA
- Department of Neurology, Mayo Clinic and Foundation, Rochester, USA
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25
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Kishimoto C, Takada H, Kawamata H, Umatake M, Ochiai H. Immunoglobulin treatment prevents congestive heart failure in murine encephalomyocarditis viral myocarditis associated with reduction of inflammatory cytokines. J Pharmacol Exp Ther 2001; 299:645-51. [PMID: 11602677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
We have previously shown that immunoglobulin therapy suppressed murine coxsackievirus B3 myocarditis. In the present study, we examined the effects of immunoglobulin upon murine myocarditis induced by encephalomyocarditis virus, which is not pathogenic to humans. Antiviral activity of immunoglobulin (Venilon) against encephalomyocarditis virus could not be detected in vitro. The production of cytokines was decreased in virus-infected macrophages by the treatment of immunoglobulin in vitro. Immunoglobulin (1 g/kg/day) was administered intraperitoneally to the virus-infected C3H/He mice daily for 2 weeks, beginning simultaneously with virus inoculation in experiment I and on day 14 after virus inoculation in experiment II. In experiment I, survival rate did not differ significantly between immunoglobulin-treated and untreated groups. In experiment II, survival rate was higher in immunoglobulin compared with control groups. Immunoglobulin administration suppressed the development of myocardial necrosis with T-lymphocyte infiltrates in mice not only in the acute viremic but in the chronic aviremic stages concomitantly associated with the reduction of inflammatory cytokines, i.e., tumor necrosis factor-alpha, interferon-gamma, macrophage inflammatory protein-2, and interleukin-6. Taken together, immunoglobulin therapy could have the potential to prevent congestive heart failure.
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Affiliation(s)
- C Kishimoto
- The Second Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Toyama, Japan.
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26
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Campbell T, Meagher MW, Sieve A, Scott B, Storts R, Welsh TH, Welsh CJ. The effects of restraint stress on the neuropathogenesis of Theiler's virus infection: I. Acute disease. Brain Behav Immun 2001; 15:235-54. [PMID: 11566048 DOI: 10.1006/brbi.2000.0598] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Restraint stress was found to have a profound effect on the acute phase of Theiler's virus infection. Increased mortality rates were observed in restrained CBA mice infected with the BeAn strain of Theiler's virus. In addition, restrained mice developed higher CNS viral titers than infected/nonrestrained mice. Thymic atrophy was observed in both infected and uninfected restrained mice. Decreased microgliosis, perivascular cuffing, and astrocytosis were observed in restrained mice compared to nonrestrained infected mice at 7 days postinfection. Restraint-stressed mice also developed decreased numbers of lymphocytes and increased numbers of neutrophils in the blood. The mechanism proposed for these alterations involves stress-induced corticosterone, which causes immunosuppression, decreased trafficking of inflammatory cells in the CNS, and, consequently, increased viral replication.
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Affiliation(s)
- T Campbell
- Department of Veterinary Anatomy and Public Health, College of Veterinary Medicine, Texas A&M University, College Station, TX 77843, USA
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27
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Miyamoto T, Matsumori A, Hwang MW, Nishio R, Ito H, Sasayama S. Therapeutic effects of FTY720, a new immunosuppressive agent, in a murine model of acute viral myocarditis. J Am Coll Cardiol 2001; 37:1713-8. [PMID: 11345389 DOI: 10.1016/s0735-1097(01)01204-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVES This study examines the efficacy of FTY720 (FTY), a new immunosuppressor, in the treatment of acute viral myocarditis in a murine model. BACKGROUND Immunosuppressive agents have no proven therapeutic efficacy in experimental or clinical myocarditis. METHODS Encephalomyocarditis virus was inoculated i.p. in DBA/2 mice on day 0. Postinoculation treatment consisted of FTY 10 mg/kg/day p.o. (FTY group), or cyclosporine A (CsA) 40 mg/kg/day p.o. (CsA group) or distilled water p.o. only (control group). Survival until day 14, as well as cardiac histopathology, virus concentrations, cytokines (interleukin [IL]-2, IL-12, interferon [IFN]-gamma and tumor necrosis factor [TNF]-alpha) and nitric oxide (NO) on day 5 were examined. RESULTS In the control and CsA groups, all mice died within 10 and 7 days, respectively. However, in the FTY group, 27% of the animals survived up to day 14. Compared with the control group, 1) histological scores were significantly lower in the FTY group but unchanged in the CsA group; 2) virus concentration was significantly higher in the CsA group but not in the FTY group; 3) expressions of IL-2, IL-12 and IFN-gamma in the heart were suppressed in both the FTY and CsA groups, though suppression was weaker in the FTY group; 4) TNF-alpha and NO were significantly increased in the CsA group but not in the FTY group. CONCLUSIONS FTY720 had a significant therapeutic effect in acute experimental myocarditis without inducing excessive virus replication. This report is the first to describe a beneficial effect by an immunosuppressive agent in the treatment of acute viral myocarditis.
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Affiliation(s)
- T Miyamoto
- Department of Cardiovascular Medicine, Kyoto University, Japan
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28
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Abstract
Type I (insulin-dependent) diabetes mellitus results from the progressive loss of pancreatic beta cells. Environmental factors are believed to play an important part in the development of Type I diabetes by influencing the penetrance of diabetes susceptibility genes. As one environmental factor, the virus has long been considered to play a part in this disease. To date 13 different viruses have been reported to be associated with the development of Type I diabetes in humans and in various animal models. The most clear and unequivocal evidence that a virus induces diabetes in animals comes from studies on the D variant of the encephalomyocarditis (EMC-D) virus in mice and the Kilham rat virus (KRV) in rats. The infection of genetically susceptible strains of mice with a high titre of EMC-D virus results in the development of diabetes within 3 days. This is largely due to the rapid destruction of beta cells by the replication of the virus within the beta cells. In contrast, the infection of mice with a low titre of EMC-D virus results in a limited replication of the virus before the induction of neutralizing anti-virus antibody and the subsequent recruitment of activated macrophages. The Src kinases, particularly hck, play an important part in the activation of macrophages and the subsequent production of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1 beta and nitric oxide (NO), leading to the destruction of beta cells which results in the development of diabetes. The Kilham rat virus causes autoimmune diabetes in diabetes resistant (DR)-BB rats without infection of beta cells. The infection of DR-BB rats with KRV results in the disruption of the finely tuned immune balance of Th1-like CD45RC+CD4+ and Th2-like CD45RC-CD4+ T cells, leading to the selective activation of beta-cell-cytotoxic effector T cells.
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Affiliation(s)
- H S Jun
- Laboratory of Viral and Immunopathogenesis of Diabetes, Julia McFarlane Diabetes Research Centre, Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
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29
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Abstract
To evaluate whether maternal illness following picornavirus infection during pregnancy adversely affects placental and fetal health, mice were inoculated with the GDVII strain of Theiler's murine encephalomyelitis virus or control cell lysate during days 4-7 of gestation. Gross appearance, histopathology and viral culture, and in situ hybridization positivity of placentae and fetuses from ill GDVII-infected, healthy GDVII-infected and control mice were compared. Twenty of 34 (59 per cent) GDVII-infected dams became clinically ill. More placenta-fetus pairs from ill mice were grossly abnormal (68 per cent) than from well GDVII-infected (51 per cent;P< 0.01) or control mice (9 per cent;P< 0.001). Virus was detected by in situ hybridization in 73 per cent of placentae and 29 per cent of fetuses from sick GDVII-infected dams, and in 85 per cent of placentae and 19 per cent of fetuses from healthy GDVII-infected mice (differences not significant). Histological abnormalities consisting of necrosis or an increase in hyaline tissue in the vascular labyrinth layer were similarly frequent in placentae from ill and well GDVII-infected mice (58 per cent versus 67 per cent, P=0.5). Viral RNA, inflammation and necrosis were evident in the heart, great vessels, brain and spinal cord of GDVII-infected fetuses. Infection with GDVII in early pregnancy produces a high rate of gross placental and fetal abnormalities. The rate of gross abnormalities exceeds the incidence of fetal infection and more closely parallels the rates of infection and histopathology in the placenta, suggesting that much of the damage to placenta-fetus pairs is a consequence of placental infection. In addition, the occurrence of viral-induced maternal illness is associated with additive risk to placental and fetal health not explained by an increased rate of placental or fetal infection.
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Affiliation(s)
- M J Abzug
- Departments of Pediatrics (Infectious Diseases) and Pathology, University of Colorado School of Medicine and The Children's Hospital, Denver, Colorado 80218, USA
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30
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Choi BK, Cho SH, Bai GH, Kim SJ, Hyun BH, Choe YK, Bae YS. Prevention of encephalomyocarditis virus-induced diabetes by live recombinant Mycobacterium bovis bacillus Calmette-Guérin in susceptible mice. Diabetes 2000; 49:1459-67. [PMID: 10969829 DOI: 10.2337/diabetes.49.9.1459] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The D variant of encephalomyocarditis (EMC-D) virus causes diabetes in susceptible mice by direct cytolysis of pancreatic beta-cells. cDNA covering the major outer capsid protein (VP1) of the EMC-D virus was cloned into Mycobacterium bovis bacillus Calmette-Guerin (BCG). None of the SJL/J mice immunized with live recombinant BCG-VP1 (rBCG-VP1) became diabetic when challenged with the highly diabetogenic EMC-D virus, but the control mice inoculated with normal BCG developed diabetes during the same challenge. VP1-specific antibodies (including neutralizing antibodies) were markedly increased over time and reached the maximum titer at week 10 after a single immunization. The plateau of the titer lasted longer than 4 weeks. Mice and guinea pigs immunized with live rBCG-VP1 showed strong delayed-type hypersensitivity to the VP1 of the EMC-D virus. The preventive immunity still worked effectively 10 months after the primary immunization. At that time, the VP1-specific antibody was almost undetectable in the bloodstream, but a large number of VP1-specific lymphocytes was found in the spleen of the immunized mice. Our results show that live rBCG-VP1 elicits effective humoral and long-lasting cellular immune responses against EMC-D virus infection that results in the prevention of virus-induced diabetes in susceptible mice.
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Affiliation(s)
- B K Choi
- Department of Microbiology, Hannam University, Taejon City, South Korea
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31
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Ure D, Rodriguez M. Extensive injury of descending neurons demonstrated by retrograde labeling in a virus-induced murine model of chronic inflammatory demyelination. J Neuropathol Exp Neurol 2000; 59:664-78. [PMID: 10952057 DOI: 10.1093/jnen/59.8.664] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Persistent Theiler's virus infection of SJL/J mice was used as a model to quantitatively assess the extent of descending neuron injury by chronic inflammatory demyelination of the spinal cord. By 9 months postinfection, inflammatory demyelinating lesions were present throughout the spinal cord, affecting up to 31% of the cross-sectional area of the ventrolateral columns. Axon dropout was evident in the lesions by electron microscopy and by quantitation of axons in normal-appearing white matter. Axon number in the ventrolateral columns at L1/L2 was reduced by 23% and total axon area was reduced by 37%, compared with uninfected mice. The most informative data on descending neuron injury, however, was a reduction in retrograde. Fluoro-Gold labeling. Labeling from T11/T12 of rubrospinal, reticulospinal/raphespinal, and vestibulospinal neurons was reduced by 60%, 70%, and 93%, respectively. Retrograde responses to axonal injury were observed, consisting of atrophied cell bodies, indented nuclei, and abundant lipofuscin, but cell body dropout was minimal. The number of cell bodies of vestibulospinal neurons was reduced by only 35%, whereas the number of cell bodies of rubrospinal neurons was unchanged. These results demonstrate that chronic inflammatory demyelination can severely injure axons and emphasize the need to design neuroprotective therapies in human multiple sclerosis.
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Affiliation(s)
- D Ure
- Department of Immunology, Mayo Medical and Graduate School, Rochester, Minnesota 55905, USA
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32
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Abstract
It has recently been speculated that progressive deterioration of left ventricular function in chronic heart failure is due to the ongoing loss of viable cardiac myocytes. However, as there is little direct evidence of significant apoptosis contributing to the pathogenesis in cardiac myocytes in vivo, the significance of apoptosis in heart failure remains to be clarified. We investigated the role of apoptosis in heart failure induced by encephalomyocarditis virus myocarditis. DBA/2 mice were inoculated with the virus (day 0), then killed, and their hearts were extracted 3 to 28 days later. Internucleosomal DNA fragmentation, chromatin binding dye staining, and in situ terminal transferase deoxyuridine triphosphate (dUTP) end-labeling were used to detect apoptosis. Internucleosomal DNA fragmentation (DNA ladder) was clearly demonstrated on days 5 to 14 in the virus-infected hearts when myocardial necrosis and infiltration of mononuclear cells were prominent in the hearts. Apoptotic cells demonstrated morphological changes typical of apoptosis (condensation of chromatin and nuclear fragmentation). Both Fas antigen and Fas ligand immunoreactivity were detected in the infiltrating mononuclear cells. The in situ terminal transferase dUTP end-labeling method demonstrated condensed nuclei of infiltrating mononuclear cells on day 7. However, nuclei of cardiac myocytes surrounded by the cellular infiltration were absent. The main source of apoptotic cells in the heart in mice with viral myocarditis appeared to be the infiltrating mononuclear cells.
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Affiliation(s)
- T Yamada
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Japan
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33
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Katz-Levy Y, Neville KL, Girvin AM, Vanderlugt CL, Pope JG, Tan LJ, Miller SD. Endogenous presentation of self myelin epitopes by CNS-resident APCs in Theiler's virus-infected mice. J Clin Invest 1999; 104:599-610. [PMID: 10487774 PMCID: PMC408545 DOI: 10.1172/jci7292] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The mechanisms underlying the initiation of virus-induced autoimmune disease are not well understood. Theiler's murine encephalomyelitis virus-induced demyelinating disease (TMEV-IDD), a mouse model of multiple sclerosis, is initiated by TMEV-specific CD4(+) T cells targeting virally infected central nervous system-resident (CNS-resident) antigen-presenting cells (APCs), leading to chronic activation of myelin epitope-specific CD4(+) T cells via epitope spreading. Here we show that F4/80(+), I-A(s+), CD45(+) macrophages/microglia isolated from the CNS of TMEV-infected SJL mice have the ability to endogenously process and present virus epitopes at both acute and chronic stages of the disease. Relevant to the initiation of virus-induced autoimmune disease, only CNS APCs isolated from TMEV-infected mice with preexisting myelin damage, not those isolated from naive mice or mice with acute disease, were able to endogenously present a variety of proteolipid protein epitopes to specific Th1 lines. These results offer a mechanism by which localized virus-induced, T cell-mediated inflammatory myelin destruction leads to the recruitment/activation of CNS-resident APCs that can process and present endogenous self epitopes to autoantigen-specific T cells, and thus provide a mechanistic basis by which epitope spreading occurs.
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Affiliation(s)
- Y Katz-Levy
- Department of Microbiology-Immunology and Interdepartmental Immunobiology Center, Northwestern University Medical School, Chicago, Illinois 60611, USA
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34
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McGavern DB, Zoecklein L, Drescher KM, Rodriguez M. Quantitative assessment of neurologic deficits in a chronic progressive murine model of CNS demyelination. Exp Neurol 1999; 158:171-81. [PMID: 10448429 PMCID: PMC5444461 DOI: 10.1006/exnr.1999.7082] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The precise factors involved in the development of a progressive motor dysfunction, a hallmark of immune-mediated demyelinating diseases such as multiple sclerosis, are not well defined. The ability to identify neurologic deficits that result in impaired motor performance early in disease may allow for the identification of therapeutic interventions that slow or eliminate the progression toward a permanent dysfunction. Here we describe the use of three objective, quantitative functional assays (spontaneous activity box, rotarod, and footprint analysis) to detect early neurologic deficits following the initiation of a demyelinating disease with Theiler's murine encephalomyelitis virus (TMEV). The results show that the assays are capable of revealing neurologic deficits at the early stages of the demyelinating disease process. These findings are the first to objectively characterize neurologic function in an animal model of progressive CNS demyelination.
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Affiliation(s)
- D B McGavern
- Department of Neurology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA
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35
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Kanda T, Utsugi T, Kawazu S, Wilson JE, Yang D, Suarez A, McManus BM, Nagai R, Kobayashi I. Induction of virus-induced IDDM in virus resistant mice without lymphocyte maturation. Life Sci 1998; 63:33-40. [PMID: 9667762 DOI: 10.1016/s0024-3205(98)00233-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The role of lymphocytes in the pathogenesis of viral-induced insulin dependent diabetes mellitus (IDDM) is controversial. To better understand how a virus-induced IDDM depends on the infiltrating lymphocytes, encephalomyocarditis virus (EMCV) was inoculated intraperitoneally into three kinds of mice; virus-susceptible C57BL/6, virus-resistant 129/SV and recombination activity gene-2 (Rag2) knockout 129/SV mice. Pancreatic inflammation and beta cell necrosis were evaluated after EMCV, D variant (10(3) pfu/mouse) inoculation. On post-inoculation day 14, the lethal rates of C57BL/6, 129/SV and Rag2 knockout mice were 52, 10 and 100%, respectively. The blood glucose in Rag2KO mice on day 8 was significantly elevated as compared with 129SV mice (231 +/- 49 vs 169 +/- 32 mg/dl, P<0.05). In situ hybridization demonstrated the EMCV genome in the pancreas of Rag2 knockout and C57BL/6 mice, but not in 129/SV mice. Beta cell necrosis were more severe in Rag-2 knockout mice than in wild type 129/SV mice, but lymphocyte infiltration was less severe than C57BL/6. Pancreas in Rag2 knockout mice infected with virus were affected more severely than the virus-resistant strain of mice. Diabetogenic virus induced IDDM in virus-resistant mice without mature lymphocytes.
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Affiliation(s)
- T Kanda
- Department of Laboratory Medicine, Gunma University School of Medicine, Gunma University, Maebashi, Japan.
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36
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Kanda T, Kogure S, Nara M, Tsukui S, Utsugi T, Tomono S, Kawazu S, Nagai R, Kobayashi I. Combination of OK432 and human interferon-alpha for treating viral-induced diabetes mellitus in mice. Eur J Pharmacol 1998; 342:297-302. [PMID: 9548400 DOI: 10.1016/s0014-2999(97)01476-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the therapeutic effects of OK432 (picibanil; CAS39325-1-4), an immunomodulator that is derived from the Su strain of Streptococcus pyogenes. This agent was administered alone or combined with human interferon-alpha in a murine model of insulin-dependent diabetes mellitus. Interferon-alpha inhibits viral replication, reducing the incidence of virus-induced IDDM. Groups of DBA/2 mice (N = 25 per group) received an intraperitoneal injection of OK432 and interferon-alpha daily for 16 d beginning 1 d after inoculation with 500 plaque-forming units of encephalomyocarditis virus (EMCV). The dose of OK432 was one clinical unit (corresponding to 0.1 mg dried cells) per mouse, and that of interferon-alpha was 1 x 10(4) u/g. The animals were killed at random at 3 or 7 d after inoculation with EMCV. The survival rate of mice treated with the combination of OK432 and with interferon-alpha was significantly greater than that of the non-treated infected control animals (P < 0.01). Fasting levels of blood glucose were significantly lower in the mice administered the combination, than in the controls, both on day 3 (68 +/- 21 mg/dl vs. 270 +/- 135 mg/dl, P < 0.01) and on day 7 (101 +/- 29 mg/dl vs. 219 +/- 112 mg/dl, P < 0.01). Serum levels of insulin were significantly higher in the treated mice than in the controls (65 +/- 5 vs. 55 +/- 1 microU/ml, P < 0.05). However, in the mice treated with OK432 or interferon-alpha alone, the survival rate and the blood level of glucose and insulin did not differ from those of infected controls. Natural killer (NK) cell activity was significantly higher in the mice treated with the drug combination than in the controls on both days evaluated: day 3, 65 +/- 5 vs. 55 +/- 1%, n = 3, P < 0.05; day 7, 44 +/- 3 vs. 22 +/- 8%, n = 3, P < 0.05). Serum levels of murine interferon in the treated mice exceeded those in controls on both days evaluated (day 3, 671 U/ml vs. 442 U/ml; day 7, 57 U/ml vs. 43 U/ml). There were no significant differences in NK cell activity or in the interferon level in mice treated with either OK432 or interferon-alpha alone as compared with the infected, non-treated controls. Results suggest that the combination of OK432 and interferon-alpha protects against virally induced IDDM by increasing the activity of NK cells as well as the plasma level of interferon.
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Affiliation(s)
- T Kanda
- Department of Laboratory Medicine, Gunma University School of Medicine, Maebashi, Japan
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37
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Abstract
The therapeutic effects of calcium channel blockers on heart failure are controversial. However, a recent clinical trial demonstrated a favorable effect of amlodipine on survival rates in patients with heart failure resulting from nonischemic dilated cardiomyopathy. There are a number of studies showing that cytokines generated by activated immune cells cause an increase in nitric oxide (NO) via induction of NO synthase (NOS), which results in a direct negative inotropic effect and a modulation of inotropic responsiveness. Increases in inflammatory circulating cytokines have been detected in patients with heart failure and cardiomyopathy, elevated plasma levels of nitrite/nitrate in patients with heart failure have been reported, and inducible NOS (iNOS) has been found in ventricular tissue from patients with dilated cardiomyopathy. In our recent study, amlodipine improved histopathological lesions in the heart and survival rates in a murine model of nonischemic heart failure induced by encephalomyocarditis virus. Amlodipine inhibited NO production in vitro and decreased the number of iNOS positive cells in vivo. In this model, the therapeutic effect of amlodipine on myocardial injury is considered in part to result from inhibition of overproduction of NO. In this review, the possible roles of cytokines and NO in the pathophysiology of heart failure are discussed, along with the opportunities for therapeutic intervention.
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Affiliation(s)
- A Matsumori
- Department of Cardiovascular Medicine, Kyoto University, Japan.
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38
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Hirasawa K, Jun HS, Maeda K, Kawaguchi Y, Itagaki S, Mikami T, Baek HS, Doi K, Yoon JW. Possible role of macrophage-derived soluble mediators in the pathogenesis of encephalomyocarditis virus-induced diabetes in mice. J Virol 1997; 71:4024-31. [PMID: 9094680 PMCID: PMC191555 DOI: 10.1128/jvi.71.5.4024-4031.1997] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Pancreatic islets from DBA/2 mice infected with the D variant of encephalomyocarditis (EMC-D) virus revealed lymphocytic infiltration with moderate to severe destruction of pancreatic beta cells. Our previous studies showed that the major population of infiltrating cells at the early stages of infection is macrophages. The inactivation of macrophages prior to viral infection resulted in the prevention of diabetes, whereas activation of macrophages prior to viral infection resulted in the enhancement of beta-cell destruction. This investigation was initiated to determine whether macrophage-produced soluble mediators play a role in the destruction of pancreatic beta cells in mice infected with a low dose of EMC-D virus. When we examined the expression of the soluble mediators interleukin-1 beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha), and inducible nitric oxide synthase (iNOS) in the pancreatic islets, we found that these mediators were clearly expressed at an early stage of insulitis and that this expression was evident until the development of diabetes. We confirmed the expression of these mediators by in situ hybridization with digoxigenin-labelled RNA probes or immunohistochemistry in the pancreatic islets. Mice treated with antibody against IL-1beta or TNF-alpha or with the iNOS inhibitor aminoguanidine exhibited a significant decrease in the incidence of diabetes. Mice treated with a combination of anti-IL-1beta antibody, anti-TNF-alpha antibody, and aminoguanidine exhibited a greater decrease in the incidence of disease than did mice treated with one of the antibodies or aminoguanidine. On the basis of these observations, we conclude that macrophage-produced soluble mediators play an important role in the destruction of pancreatic beta cells, resulting in the development of diabetes in mice infected with a low dose of EMC-D virus.
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Affiliation(s)
- K Hirasawa
- Department of Microbiology and Infectious Disease, Faculty of Medicine, University of Calgary, Alberta, Canada
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39
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Abstract
In an IDDM model mouse which was inoculated with a diabetogenic variant, DK-27, of encephalomyocarditis (EMC) virus, the relation between a stable glycated hemoglobin A1C (St-HbA1C) level and plasma glucose level (PGL) in the progress of diabetes was studied. The St-HbA1C level and PGL were examined every 2 weeks for 10 weeks in normal male DBA/2 and IDDM-onset mice. PGLs of normal control mice did not change, but their St-HbA1C levels were slightly increased by 0.52 to 1.03%. On the other hand, in IDDM mice, their PGLs were greatly increased (> 400 mg/dl) and hyperglycemia was maintained throughout this observation period, with their St-HbA1C noticeably increased to 3.8% according to the progress of diabetes for 10 weeks. A highly significant correlation between St-HbA1C levels and averaged PGLs for the past weeks was found in IDDM mice. To examine the reflection of St-HbA1C levels to delicately varied PGLs, we also estimated both values in IDDM mice which were treated with insulin at a minimal effective dose once a day for 4 weeks. The St-HbA1C levels in insulin-injected IDDM mice were significantly lower than those in control IDDM mice. These findings suggest that the estimation of the St-HbA1C level is useful in following up blood glucose control in a long-term therapeutical study with small laboratory animals.
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Affiliation(s)
- K Dan
- Division of Chemotherapy, School of Medicine, Keio University, Tokyo, Japan
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40
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Wang WZ, Matsumori A, Yamada T, Shioi T, Okada I, Matsui S, Sato Y, Suzuki H, Shiota K, Sasayama S. Beneficial effects of amlodipine in a murine model of congestive heart failure induced by viral myocarditis. A possible mechanism through inhibition of nitric oxide production. Circulation 1997; 95:245-51. [PMID: 8994443 DOI: 10.1161/01.cir.95.1.245] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Although calcium channel blockers have not been shown to be beneficial for the treatment of patients with heart failure, a recent clinical trial demonstrated a favorable effect of amlodipine on the survival of patients with heart failure resulting from nonischemic dilated cardiomyopathy. We investigated the effects of amlodipine on a murine model of congestive heart failure induced by the M variant of encephalomyocarditis virus (EMCV). METHODS AND RESULTS Four-week-old male DBA/2 mice were inoculated with EMCV and administered amlodipine, diltiazem, or vehicle PO for 2 weeks. The heart weight-to-body weight ratio and the histopathological grades of myocardial lesions were significantly lower and survival was significantly increased in the amlodipine-treated group (P < .01, P < .05, and P < .05, respectively) than in the control group. In vitro, amlodipine added to murine J774A.1 macrophages concomitant with EMCV inhibited nitrite formation in a concentration-dependent manner, but diltiazem did not. Furthermore, NG-monomethyl-L-arginine, an inhibitor of NO synthesis, decreased myocardial lesions significantly in this murine model. Immunohistochemistry revealed that the number of cells stained with antibody against an inducible NO synthase decreased significantly in the amlodipine-treated group compared with that in the control group (P < .01). CONCLUSIONS Amlodipine appears to have a protective effect against myocardial injury in this animal model of congestive heart failure. The therapeutic effect of amlodipine may be in part resulting from inhibition of overproduction of NO.
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Affiliation(s)
- W Z Wang
- Department of Cardiovascular Medicine, Kyoto University, Japan
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41
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Jun HS, Yoon SW, Kang Y, Pak CY, Lee MC, Yoon JW. Cloning and expression of the VP1 major capsid protein of diabetogenic encephalomyocarditis (EMC) virus and prevention of EMC virus-induced diabetes by immunization with the recombinant VP1 protein. J Gen Virol 1995; 76 ( Pt 10):2557-66. [PMID: 7595359 DOI: 10.1099/0022-1317-76-10-2557] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The development of diabetes in mice induced by encephalomyocarditis (EMC) virus provides the best experimental evidence that viruses have an aetiological role in the pathogenesis of this disease. The major capsid protein (VP1) of EMC virus is important for both the attachment of the virus to pancreatic beta cells and for the determination of antigenicity. This experiment was initiated to clone the gene for the major capsid protein, VP1, of the diabetogenic EMC (EMC-D) virus, express the VP1 protein, and test whether the recombinant VP1 protein can prevent development of EMC-D virus-induced diabetes in mice. We successfully cloned the VP1 gene of the EMC-D virus in the expression vector pRSET and subsequently expressed the protein in Escherichia coli. The recombinant VP1 protein was then purified by affinity chromatography. Five- to six-week-old male SJL/J mice were immunized intraperitoneally with purified VP1 protein and then challenged after various intervals with highly diabetogenic EMC-D virus. None of the VP1-immunized mice developed diabetes, irrespective of the interval between immunization and virus challenge, whereas 80 to 95% of the EMC-D virus-infected control mice did develop diabetes. All of the VP1-immunized mice showed intact pancreatic islet architecture, whereas most of the infected control mice showed severe beta cell necrosis and lymphocytic infiltration of their pancreatic islets. On the basis of these observations, we conclude that the recombinant VP1 protein of EMC-D virus can completely prevent the development of EMC-D virus-induced diabetes in mice.
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Affiliation(s)
- H S Jun
- Department of Microbiology and Infectious Diseases, Faculty of Medicine, University of Calgary, Alberta, Canada
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Dan K, Seto Y, Fujita T, Asaba Y, Takei I, Fujita H, Kato R. Characterization of insulin-dependent diabetes mellitus induced by a new variant (DK-27) of encephalomyocarditis virus in DBA/2 mice. Exp Anim 1995; 44:211-8. [PMID: 7556422 DOI: 10.1538/expanim.44.211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
A murine diabetes mellitus induced with a new diabetogenic variant (DK-27) which we isolated from the M variant of the encephalomyocarditis (EMC) virus was characterized. Male DBA/2 mice (9.5 weeks old) were infected with various infectious doses of DK-27 intraperitoneally. Blood glucose and insulin levels were examined in association with the viral replication. Pancreatic pathology and hormone contents and stable hemoglobin A1c (St-A1c) levels were also examined on the final day of observation (35 days of post-infection). In infected mice, blood glucose levels rapidly elevated at 72 hr, slightly decreased between 7 and 10 days and finally became sustained hyperglycemia. On the other hand, blood insulin levels elevated at 48 hr, promptly decreased, and subsequently became sustained hypoinsulinemia. Viral replication in pancreases reached the highest titers at 48 hr and rapidly disappeared with all infectious doses used. Pancreatic insulin contents in infected mice were not detectable, and glucagon contents were not affected. In pathological examination, atrophy of islets and marked diminution of B-cells were observed, and A-cells occupied the major part of an infected islet. St-A1c levels reflected lasting hyperglycemia. These findings show that DK-27 causes insulin-dependent diabetes mellitus by the specific and direct destruction of pancreatic B-cells in susceptible mice. Such a diabetic model mouse will be useful for therapeutic studies.
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Affiliation(s)
- K Dan
- Division of Chemotherapy, School of Medicine, Keio University, Tokyo, Japan
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43
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Abstract
Encephalomyocarditis (EMC) virus infection in the common vole was examined for the first time. Sixteen 8-week-old males inoculated intraperitoneally with 10(5) plaque-forming units (pfu)/animal of the D variant of EMC virus were killed 3 and 7 days after inoculation (3 and 7 DAI). Viral replication was detected in the brain (10(5) pfu/g), heart (10(4) pfu/g) and pancreas (10(7) pfu/g) of all 8 animals at 3DAI. It was found in the pancreas (10(3) pfu/g) of all 8 animals and in the brain (10(4) pfu/g) of 2 of 8 animals at 7 DAI. Histopathological changes were observed in the brain (mild mononuclear cell infiltration around capillaries and sporadic pyknosis of neurons), heart (minimal myocardial necrosis) and pancreas (prominent acinar cell necrosis with inflammatory exudation) at 3DAI. At 7 DAI, replacement of necrotic tissues by mesenchymal cells and regeneration of acinar cells were conspicuous in the pancreas. Throughout the experimental period, no evidence for diabetogenic effect was found.
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Affiliation(s)
- K Doi
- Department of Biomedical Science, Faculty of Agriculture, University of Tokyo, Japan
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44
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Abstract
Characteristics of encephalomyocarditis (EMC) virus-induced testicular lesions were investigated in 4- and 8-week-old BALB/c male mice after intraperitoneal (i.p.) and intratesticular (left) (i.t.) inoculation of the D variant of EMC virus (EMC-D). Apart from variation in severity and incidence, the histopathological nature of the resultant testicular lesion was similar in all infected mice, and was characterized by degeneration and necrosis of germinal cells and spermatogonia with inflammatory infiltration. Almost all the inoculated left testes of the i.t. group developed marked lesions. In general, the virus titre in the testis and incidence of testicular lesions were higher in 4-week-old mice than in 8-week-old mice. In addition, testicular lesions developed earlier and with a higher incidence in the PBS-inoculated right testis of the i.t. group than in either testis of the i.p. group of the same age.
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Affiliation(s)
- M Shigesato
- Department of Biomedical Science, Faculty of Agriculture, University of Tokyo, Japan
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45
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Abstract
In this study, a transplacental infection with fetal death was demonstrated following inoculation of pregnant sows with a Belgian encephalomyocarditis virus (EMCV) isolate. Eight multiparus sows were inoculated between 60 and 92 days of gestation with this EMCV-isolate to investigate its ability to cause reproductive failure in sows. Virus persistence and antibody titre in their offspring were also studied. Only the two sows inoculated at 60 days of gestation showed premature farrowing, but all sows seroconverted to EMCV. Virus was recovered from the offspring of all sows at the time of farrowing, but not from every piglet born. One month after birth EMCV could be isolated from all the piglets examined. These results can help in a better understanding of the spread of the disease in piggeries.
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Affiliation(s)
- F Koenen
- Nationaal Instituut voor Diergeneeskundig Onderzoek (NIDO-INRV), Ukkel,Belgium
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