Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014070 (encephalomyelitis)
 13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Viral infections of the central nervous system and immune responses to these infections cause a variety of neurological diseases. Infection of weanling mice with Sindbis virus causes acute nonfatal encephalomyelitis followed by clearance of infectious virus, but persistence of viral RNA. Infection with a neuroadapted strain of Sindbis virus (NSV) causes fatal encephalomyelitis, but passive transfer of immune serum after infection protects from fatal disease and infectious virus is cleared. To determine whether persistent NSV RNA is associated with neurological damage, we examined the brains of recovered mice and found progressive loss of the hippocampal gyrus, adjacent white matter, and deep cerebral cortex associated with mononuclear cell infiltration. Mice deficient in CD4(+) T cells showed less tissue loss, while mice lacking CD8(+) T cells showed lesions comparable to those in immunocompetent mice. Mice deficient in both CD4(+) and CD8(+) T cells developed severe tissue loss similar to immunocompetent mice and this was associated with extensive infiltration of macrophages. The number of CD4(+) cells and macrophage/microglial cells, but not CD8(+) cells, infiltrating the hippocampal gyrus was correlated with the number of terminal deoxynucleotidyltransferase-mediated dUTP nick end-labeling positive pyramidal neurons. These results suggest that CD4(+) T cells can promote progressive neuronal death and tissue injury, despite clearance of infectious virus.
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PMID:Extensive immune-mediated hippocampal damage in mice surviving infection with neuroadapted Sindbis virus. 1283

Theiler's murine encephalomyelitis virus (TMEV) induces a chronic demyelinating disease in the central nervous system of susceptible mice. Resistance to persistent TMEV infection maps to he D locus of the major histocompatibility complex suggesting a prominent role of antiviral CTL in the protective immune response. Introduction of the D(b) gene into the FVB strain confers resistance to this otherwise susceptible mouse line. Infection of the FVB/D(b) mouse with TMEV provides a model where antiviral resistance is determined by a response elicited by a single class I molecule. Resistant mice of the H-2(b) haplotype mount a vigorous H-2D(b)-restricted immunodominant response to the VP2 capsid protein. To investigate the extent of the contribution of the immunodominant T cell population in resistance to TMEV, FVB/D(b) mice were depleted of VP2-specific CD8(+) T cells by peptide treatment prior to virus infection. Peptide-treated mice were not able to clear the virus and developed extensive demyelination. These findings demonstrate that the D(b)-restricted CD8(+) T cells specific for a single viral peptide can confer resistance to TMEV infection. Our ability to manipulate this cellular response provides a model for investigating the mechanisms mediating protection against virus infection by CD8(+) T cells.
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PMID:Clearance of Theiler's virus infection depends on the ability to generate a CD8+ T cell response against a single immunodominant viral peptide. 1293 26

Infection of adult C57BL/6 (B6) mice with mouse adenovirus type 1 (MAV-1) results in dose-dependent encephalomyelitis. Utilizing immunodeficient mice, we analyzed the roles of T cells, T-cell subsets, and T-cell-related functions in MAV-1-induced encephalomyelitis. T cells, major histocompatibility complex (MHC) class I, and perforin contributed to acute disease signs at 8 days postinfection (p.i.). Acute MAV-1-induced encephalomyelitis was absent in mice lacking T cells and in mice lacking perforin. Mice lacking alpha/beta T cells had higher levels of infectious MAV-1 at 8 days, 21 days, and 12 weeks p.i., and these mice succumbed to MAV-1-induced encephalomyelitis at 9 to 16 weeks p.i. Thus, alpha/beta T cells were required for clearance of MAV-1. MAV-1 was cleared in mice lacking perforin, MHC class I or II, CD4+ T cells, or CD8+ T cells. Our results are consistent with a model in which either CD8+ or CD4+ T cells are sufficient for clearance of MAV-1. Furthermore, perforin contributed to MAV-1 disease but not viral clearance. We have established two critical roles for T cells in MAV-1-induced encephalomyelitis. T cells caused acute immunopathology and were required for long-term host survival of MAV-1 infection.
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PMID:T cells cause acute immunopathology and are required for long-term survival in mouse adenovirus type 1-induced encephalomyelitis. 1294 16

In three cases of encephalitis in humans that occurred in the area where the newly described California virus was isolated from mosquitoes, serological evidence seemed to indict the California virus as the etiological agent. In the case of an infant with very severe disease, the serological evidence was convincing; the evidence was almost as strong in the case of a seven-year-old boy; the results in an adult were equivocal. Inapparent infection in man is quite common as indicated by neutralization tests on the sera of nearly 600 residents of California, but encephalitic manifestations of infection are extremely rare. In Kern County, California, where the virus was discovered, approximately 11 per cent of the population has been infected. Infection rates are higher in adults than in very young children. Absence of neutralizing antibodies from 64 specimens of blood from persons in Japan, Washington, and other states supports the specificity of the neutralization test in man and suggests that this virus is absent or is not being similarly transmitted in some areas. Serological evidence from serial bleedings of two sick horses suggested, but did not definitely establish, that this virus leads to a naturally acquired encephalomyelitis in horses. Serological tests with the viruses of western equine and St. Louis encephalitis did not lead to any other etiological diagnosis in the sick animals studied. Results of neutralization tests on the sera of eight horses and three cows in Kern County suggested extremely high infection rates, and an immunity rate of 18 per cent was noted in rabbits and ground squirrels. In the natural biological cycle rabbits and ground squirrels are suspected as the possible counterpart of birds in the St. Louis and western equine virus cycles. There is no evidence from field or laboratory to indicate that birds become infected with the California virus. Sera from 33 mammals other than man were collected from Northern California and Washington. All were free from neutralizing antibodies, again supporting the specificity of positive findings from Kern County.
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PMID:California encephalitis virus, a newly described agent. 1300 79

CCL2 is a member of the CC chemokine family that mediates the migration and recruitment of monocytes and T cells and has been identified in the central nervous system (CNS) during several neuroinflammatory diseases. In order to examine the biological effect of constitutive CCL2 expression in the CNS, the authors engineered a mouse that expressed CCL2 in the CNS under control of the human glial fibrillary acidic protein (hGFAP) promoter. The results demonstrated that transgenic expression of CCL2 in the CNS resulted in diffuse CNS monocyte infiltration and accumulation. Transgenic CCL2 expression did not alter normal development, differentiation, or function of T cells. There was no evidence of overt CNS disease or other pathologic phenotype when mice were left unchallenged with antigen or uninfected. However, when CCL2 transgenic mice were given a peripheral challenge of lipopolysaccharide (LPS), an inflammatory infiltrate with organized perivascular lesions developed. Infection of the transgenic mice with Theiler's murine encephalomyelitis virus (TMEV) resulted in accelerated onset and increased severity of clinical and histological disease. These results suggest that CCL2 expression in the CNS is a major pathogenic factor that drives macrophage accumulation in the development of CNS inflammatory disease.
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PMID:CCL2 transgene expression in the central nervous system directs diffuse infiltration of CD45(high)CD11b(+) monocytes and enhanced Theiler's murine encephalomyelitis virus-induced demyelinating disease. 1460 75

Infection with different picornaviruses can cause meningitis/encephalitis in humans and experimental animals. To investigate the mechanisms of such inflammatory diseases, potential chemokine gene activation in human astrocytes was investigated following infection with Theiler's murine encephalomyelitis virus (TMEV), coxsackievirus B3 (CVB3), or coxsackievirus B4 (CVB4). We report that all these viruses are potent inducers for the expression of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) genes in primary human astrocytes, as well as in an established astrocyte cell line (U-373MG). Further studies indicated that both activator protein-1 (AP-1) and NF-kappaB transcription factors are required in the activation of chemokine genes in human astrocytes infected with various picornaviruses. Interestingly, the pattern of activated chemokine genes in human astrocytes is quite restricted compared to that in mouse astrocytes infected with the same viruses, suggesting species differences in gene activation. This may result in potential differences in the pathogenic outcome in each species.
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PMID:Induction of chemokines in human astrocytes by picornavirus infection requires activation of both AP-1 and NF-kappa B. 1473 Jul 2

Viral infections of the adult are fortunately rare conditions but may carry serious clinical sequelae. Infection is usually acquired by haematogenous spread during a systemic viral illness and may be acute, subacute or chronic. The pathological basis of neuronal degeneration and attempt to repair is common to all illnesses and diagnosis is generally made by analysis of the pattern of disease. Magnetic resonance imaging is now the mainstay of imaging diagnosis. Acute infections include encephalitis due to a wide range of infecting agents and outcome depends on the severity of the acute episode. Subacute and chronic infections, including HIV encephalopathy, most often produce a progressive leucoencephalopathy and ultimately cerebral atrophy. Additionally, disease may also be immune mediated, that most closely associated with viral infection being acute disseminated encephalomyelitis, which is usually a monophasic illness. Finally, prion diseases are characterised by long incubation period and progressive course, leading to death.
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PMID:Cranial viral infections in the adult. 1474 62

Intracerebral infection with Theiler's virus induces a demyelinating disease that resembles human MS. In order to delineate the early events in virus-induced inflammatory disease, we have analyzed chemokine gene activation following Theiler's murine encephalomyelitis virus (TMEV) infection. Infection of primary astrocyte cultures results in activation of various chemokine genes (GRO-1, MCP-1, MCP-5, MIP-1alpha, MIP-1beta, MIP-2, RANTES, IP-10 and MCP-3) that are important in the initiation of an inflammatory response. As early as 1-3 h after TMEV infection, chemokine gene expression is strongly activated. In addition, proinflammatory cytokines do not interfere with TMEV-induced chemokine gene expression and some cytokines may function synergistically for virus-induced upregulation of chemokine gene expression. Chemokine gene activation by TMEV appears to be largely independent of the IFNalphabeta pathway and partly dependent on dsRNA-dependent protein kinase (PKR) and MAP kinase pathways. However, TMEV-induced chemokine gene expression is completely dependent on the NFkappaB pathway. These results strongly suggest that the expression of select chemokine genes upon TMEV infection is activated via the NFkappaB pathway, similar to that of proinflammatory cytokine genes, and these cellular gene products appear to synergistically promote inflammatory responses in the CNS.
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PMID:The scope and activation mechanisms of chemokine gene expression in primary astrocytes following infection with Theiler's virus. 1502 72

Molecular mimicry is the main postulated mechanism by which infectious agents induce autoimmune disease. A number of animal models have been utilized to establish a link between molecular mimicry and autoimmunity. However, a model of infectious disease whereby a natural pathogen expressing a known mimic epitope can induce autoimmunity to a known self-antigen leading to clinical autoimmune disease is still lacking. We have engineered a recombinant Theiler's murine encephalomyelitis virus (TMEV) to express an encephalitogenic myelin proteolipid protein PLP139-151 epitope (PLP-TMEV) and a PLP139-151 mimic peptide naturally expressed by Haemophilus influenzae (HI-TMEV). Infection of mice with either PLP-TMEV or HI-TMEV induces early-onset disease that is associated with the activation of cross-reactive PLP139-151-specific immunopathologic CD4+ Th1 cells. Based on results from this model, we hypothesize, due to the considerable degeneracy in the T cell repertoire, that induction of full-blown autoimmune disease via molecular mimicry is a tightly regulated process requiring multiple factors related to the pathogen expressing the potential mimic epitope. In this review, we will discuss how various factors related to the infectious environment control whether or not autoimmune disease is initiated. Contributing factors include the nature of the innate immune response to the pathogen which determines the immunopathologic potential of the induced cross-reactive T cells, the capacity of the mimic epitope to be processed and presented from its natural flanking sequences in the pathogen-encoded protein, the site(s) of the primary infection in the host and the ability of the pathogen to persist, and the potential requirement for multiple infections with the same or different pathogens.
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PMID:Innate and adaptive immune requirements for induction of autoimmune demyelinating disease by molecular mimicry. 1503 15

Persistent Theiler's virus infection in the central nervous system (CNS) of mice provides a highly relevant animal model for multiple sclerosis. The low-neurovirulence DA strain uses sialic acid as a coreceptor for cell binding before establishing infection. During adaptation of DA virus to growth in sialic acid-deficient cells, three amino acid substitutions (G1100D, T1081I, and T3182A) in the capsid arose, and the virus no longer used sialic acid as a coreceptor. The adapted virus retained acute CNS virulence, but its persistence in the CNS, white matter inflammation, and demyelination were largely abrogated. Infection of murine macrophage but not oligodendrocyte cultures with the adapted virus was also significantly reduced. Substitution of G1100D in an infectious DA virus cDNA clone demonstrated a major role for this mutation in loss of sialic acid binding and CNS persistence. These data indicate a direct role for sialic acid binding in Theiler's murine encephalomyelitis virus persistence and chronic demyelinating disease.
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PMID:Virus persistence in an animal model of multiple sclerosis requires virion attachment to sialic acid coreceptors. 1528 Apr 94


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