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)

Mice adoptively-sensitized to develop chronic relapsing experimental autoimmune encephalomyelitis (EAE), a model for the human demyelinating condition, multiple sclerosis (MS), were given injections of recombinant human IL-10 at various timepoints post-sensitization in an attempt to abrogate disease development. IL-10 is a Th2 immunomodulatory cytokine with known down-regulatory effects upon Th1 responses and macrophages. Contrary to a previous report on EAE and the predicted outcome, after repeated experiments, IL-10 was found to elicit a worsening or no effect upon EAE in the mouse. Animals were studied clinically, histopathologically and immunocytochemically. On no occasion was disease ameliorated by IL-10. Pretreatment with IL-10 of lymph node cells used to transfer EAE had no effect upon disease outcome, indicating that the cells were already committed effectors. Administration of anti-IL-10 monoclonal antibody before onset of signs had no effect when given early post-sensitization and caused marked worsening when given immediately before onset of signs. In the context of this autoimmune demyelinating model, these results suggest that IL-10 alone is insufficient to reverse the effector response and indeed may serve to enhance the cascade of events in EAE.
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PMID:IL-10 fails to abrogate experimental autoimmune encephalomyelitis. 889 85

Experimental allergic encephalomyelitis (EAE), an animal model resembling multiple sclerosis (MS), is mediated by myelin antigen-specific CD4+ T cells secreting cytokines such as interferon-gamma (IFN-gamma), tumor necrosis factor-beta (TNF-beta), and the proinflammatory cytokine TNF-alpha-all associated with the T-helper-1 (Th1) T cell subset. Based on numerous similarities between MS and EAE, it has been postulated that Th1-like T cells are involved in the pathogenesis of MS. Production of proinflammatory cytokines such as IFN-gamma and, in particular, TNF-alpha/beta by autoreactive T cells is considered crucial for the initiation and amplification of inflammatory brain lesions and possibly also for direct myelin damage. In contrast, regulatory cytokines such as interleukin-4 (IL-4), IL-10, and IL-13, which are associated with the Th2-like phenotype, may play a role in the resolution of relapses. Although the human T cell response to myelin basic protein (MBP) is well characterized in terms of antigen specificity, HLA restriction, and T cell-receptor (TCR) usage, little is known about the cytokine pattern of these autoreactive T cells. To gain such information, conditions for studying cytokine secretion by human autoreactive T cell clones (TCC) were established. The cytokine secretion profile of human autoreactive CD4+ TCC, specific for myelin basic protein peptide (83-89) [MBP(83-99)], a candidate autoantigen in MS, was investigated. Our results show that TCC cytokine production in long-term culture was stable. In addition, the correlation of various cytokines within specific TCC revealed differences compared to murine T cells. The comparison of 30 human MBP (83-99)-specific TCC demonstrated heterogeneity in cytokine secretion, with a continuum between Th1- and Th2-like cells rather than distinct Th1 or Th2 subsets. These data are important for further investigation of the potential role of cytokines in the inflammatory process of MS, and provide a powerful tool to investigate therapeutic interventions with respect to their influence on cytokine secretion of autoreactive T cells.
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PMID:Cytokine phenotype of human autoreactive T cell clones specific for the immunodominant myelin basic protein peptide (83-99). 889 97

Development of T helper cell (Th)1 or Th2 cytokine responses is essential for effector and regulatory functions of T helper cells. We have compared cytokine profiles of myelin basic protein (MBP) Ac1-16 peptide-specific T helper cells from inbred mouse strains expressing identical k haplotype-derived MHC class II molecules B10.A and B10.BR, B10.BR T cell lines (TCL) produced Th1 cytokines (including high levels of TNF-alpha) and induced experimental autoimmune encephalomyelitis after adoptive transfer. In contrast, B10.A TCL produced Th2 cytokines (including low levels of TNF-alpha) and were poorly encephalitogenic. The contributions of the genetic origin of the T cells and the APC were explored. Serial restimulations of the B10.BR TCL with B10.A or (B10.A x B10.BR) F1 splenic antigen presenting cells (APC) during the establishment of TCL markedly reduced both Th1 cytokine production and encephalitogenicity. In addition, a single restimulation with B10. A splenic APC reduced IFN-gamma and TNF-alpha production by established Th1 MBP-specific Ak-restricted B10.BR TCL and by a Th1 KLH-specific, Ek-restricted B10.BR T cell clone. These studies suggest that B10.A and B10.BR APC differ in their ability to stimulate IFN-gamma and TNF-alpha production by mature Th1 cells and also influence their Th1/Th2 commitment in vivo. The nature of the downregulatory activity of B10.A APC on IFN-gamma and TNF-alpha production was explored. 2-hour supernatants from antigen-activated B10.A APC/TCL cultures or from B10.A APC activated by LPS had the same inhibitory effects on IFN-gamma and TNF-alpha production by B10.BR TCL. The downregulatory effects of B10.A APC are independent of TNF-alpha, IL-4, IL-10, IL-12p40, IFN-gamma, IL-13, TGF-beta, and PGE2. Thus, genetic difference(s) between B10.A and B10.BR APC appear(s) to control the production or activity of a novel soluble cytokine regulatory factor that influences Th1/Th2 commitment and controls production of IFN-gamma and TNF-alpha by mature Th1 cells.
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PMID:Novel genetic regulation of T helper 1 (Th1)/Th2 cytokine production and encephalitogenicity in inbred mouse strains. 905 44

Aminoguanidine (AG), a selective inhibitor of inducible nitric oxide synthase, prevented the clinical development of experimental autoimmune encephalomyelitis (EAE) with a reduction in inflammation and demyelination. Administration of AG reduced the expression of nitrosotyrosine in inflammatory lesions in the central nervous system. Cytokine expression, determined by semiquantitative PCR, revealed increased expression of IFN-gamma, IL-10, and TGF-beta, which was associated with protection from EAE, and reduced TNF-alpha, associated with the development of EAE. Furthermore, AG blocked the secretion of nitric oxide, TNF-alpha, and PGE2 in astrocyte cultures. AG did not influence the proliferation response of T cells to a pathogenic epitope of myelin basic protein. Down-regulation of nitric oxide by AG has widespread consequences for cytokine production in central nervous system inflammation and prevents EAE.
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PMID:Inhibition of nitric oxide synthase for treatment of experimental autoimmune encephalomyelitis. 905 33

Cytokines are important mediators in the pathogenesis of central nervous system (CNS) inflammatory diseases including multiple sclerosis (MS), experimental allergic encephalomyelitis (EAE), viral encephalitis and virus induced demyelinating diseases. We have used immunohistochemical techniques to characterize the mononuclear cell infiltrate and cytokine profiles in the CNS following infection of mice with the demyelinating A7(74) strain of Semliki Forest virus (SFV), an important viral model of MS. Mononuclear cell infiltrates in the CNS, first observed at 3 days and maximal during clearance of infectious virus, were comprised predominantly of CD8+ lymphocytes. F4/80+ macrophage/microglia and CD45/B220+ B lymphocytes were most numerous during the subsequent phase of demyelination. CD4+ T-lymphocytes were observed at low levels throughout infection. By immunostaining MHC class I, IL-1beta , IL-3 and TGF beta1 were constitutively expressed in normal mice and were upregulated following infection. MHC class II, IL-1alpha, IL-2, IL-2R, TNF-alpha and IL-6 were strongly upregulated in the CNS of SFV-infected mice and mice with chronic relapsing EAE. The spatial and temporal distribution of these cytokines during the course of disease was analysed. Whereas IL-1alpha, IL-1beta, IL-10, and TGF beta1 were observed on day 3 following infection GMCSF, IL-2 and TNF alpha were first apparent at day 7 when the cellular infiltration in the CNS was most intense. In contrast IFN gamma and IL-6 were first observed on day 10 prior to the demyelination phase of disease. Cytokines in the lesions of demyelination suggest a role in the pathogeneisis of myelin damage. Based on cytokine profiles no clear bias of either a Th1 or Th2 response was observed in the CNS during infection.
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PMID:Characterization of the cellular and cytokine response in the central nervous system following Semliki Forest virus infection. 911 72

Interferon tau is a type I IFN that was originally identified as a pregnancy recognition hormone produced by trophoblast cells. It is as potent an antiviral agent as IFN alpha and IFN beta, but lacks the toxicity associated with high concentrations of these IFNs in tissue culture and in animal studies. We recently showed that IFN tau, like IFN beta, can prevent the development of experimental allergic encephalomyelitis (EAE). We report here that IFN tau prevents EAE in mice by induction of suppressor cells and suppressor factors. Suppressor cells can be induced by IFN tau in tissue culture, and in vivo by either intraperitoneal injection or by oral administration to mice. Incubation of suppressor cells with myelin basic protein (MBP)-sensitized T cells blocked or delayed the MBP-induced proliferation. Further intraperitoneal injection of suppressor cells into mice blocked induction of EAE by MBP. Suppressor cells possessed the CD4 T cell phenotype, and produced soluble suppressor factors that inhibited MBP activation of T cells from EAE mice. The suppressor factors were found to be IL-10 and TGF beta, which acted synergistically to inhibit the MBP activation of T cells from EAE mice. These findings are important for understanding the mechanism(s) by which type I IFNs protect against autoimmune disease.
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PMID:CD4 T suppressor cells mediate interferon tau protection against experimental allergic encephalomyelitis. 914 35

Experimental autoimmune encephalomyelitis (EAE) is a CD4+ T cell-mediated, inflammatory demyelinating disease of the central nervous system (CNS) that serves as a model for multiple sclerosis (MS). The mechanisms behind differences in clinical course of EAE in different rat strains have not been defined. We induced acute EAE in Lewis rats and protracted relapsing EAE (PR-EAE) in DA rats and examined mRNA expression of IL-1 beta, IL-6, IL-10, IL-12, and TNF-beta in brain tissue sections, cerebrospinal fluid (CSF) cells, and lymph node cells. IL-1 beta, IL-12 and TNF-beta mRNA expression in brain tissue sections appeared early and peaked at the height of clinical signs in both acute and PR-EAE, consistent with a disease-promoting role for these cytokines. High levels of IL-6 mRNA-expressing cells were present in CNS and lymph node cells in PR-EAE, while almost absent in acute EAE. In contrast, IL-10 was very low in PR-EAE but strongly expressed in acute EAE, in particular during clinical recovery. Regulatory changes of IL-6 and IL-10 both systemically and within the CNS, but with temporal differences between compartments, seem pivotal for development of PR-EAE in DA rats. These findings could have relevance for pathogenesis and treatment of MS.
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PMID:High IL-6 and low IL-10 in the central nervous system are associated with protracted relapsing EAE in DA rats. 918 55

Female SJL mice are more susceptible than male mice to experimental autoimmune encephalomyelitis (EAE) induced by myelin basic protein (MBP)-specific T lymphocytes. In the present study, we examined mechanisms involved in this gender-related difference in disease susceptibility. MBP-specific T lymphocytes derived from spleens of males during the effector phase of adoptive EAE produced significantly higher levels of IL-10, an anti-inflammatory cytokine in EAE. A protective effect of testosterone was then shown. Females implanted with dihydrotestosterone pellets demonstrated a significantly less severe course of EAE as compared with females implanted with placebo pellets. Finally, MBP-specific T lymphocytes derived from dihydrotestosterone-implanted females produced significantly higher levels of IL-10 than those from placebo. Together these data indicate that testosterone exerts a protective effect in EAE that is mediated at least in part by enhanced production of IL-10 by autoantigen-specific T lymphocytes.
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PMID:Testosterone therapy ameliorates experimental autoimmune encephalomyelitis and induces a T helper 2 bias in the autoantigen-specific T lymphocyte response. 920 Apr 30

The potential role(s) of cytokines in the reduction of infectious virus and persistent viral infection in the central nervous system was examined by determining the kinetics of cytokine mRNA expression following infection with the neurotropic JHM strain of mouse hepatitis virus. Mice were infected with an antibody escape variant which produces a nonlethal encephalomyelitis and compared to a clonal virus population which produces a fulminant fatal encephalomyelitis. Infection with both viruses induced the accumulation of mRNAs associated with Th1- and Th2-type cytokines, including IFN-gamma, IL-4, and IL-10. Peak mRNA accumulations were coincident with the clearance of virus and there was no obvious differences between lethally and nonlethally infected mice. TNF-alpha mRNA was induced more rapidly in lethally infected mice compared to mice undergoing a nonfatal encephalomyelitis. Rapid transient increases in the mRNAs encoding IL-12, iNOS, IL-1alpha, IL-1beta, and IL-6 occurred following infection. Nonlethal infections were associated with increased IL-12, IL-1beta, and earlier expression of IL-6, while lethal infections were associated with increased iNOS and IL-1alpha mRNA. These data suggest a rapid but differential response within the central nervous system cells to infection by different JHMV variants. However, neither the accumulation nor kinetics of induction provide evidence to distinguish lethal infections from nonlethal infections leading to a persistent infection. Accumulation of both Th1 and Th2 cytokines in the central nervous system of JHMV-infected mice is consistent with the participation of both cytokines and cell immune effectors during resolution of acute viral-induced encephalomyelitis.
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PMID:Kinetics of cytokine mRNA expression in the central nervous system following lethal and nonlethal coronavirus-induced acute encephalomyelitis. 921 50

IL-10 and IL-4 were studied with respect to their capacity to inhibit experimental allergic encephalomyelitis (EAE) induced in SJL/J mice by immunization with the proteolipid protein peptide PLP139-151. Treatment with 2 micrograms IL-10/day from day 0 until day 12 delayed onset of disease and inhibited the severity of EAE. By contrast, a daily dose of 0.5 microgram IL-4 was ineffective. Instead of acting in a synergistic fashion, IL-4 even abrogated the inhibitory effect of IL-10. The effects of IL-10 and IL-4 treatment were largely consistent with the (lack of) ability of these cytokines to down-regulate the inflammatory response in brain tissue. Although IL-4 was ineffective in the inhibition of EAE, lymph node cells from IL-4-treated mice displayed a strongly inhibited peptide-specific IFN-gamma production. By contrast, IL-10, which was effective in inhibiting EAE, showed no significant inhibition of IFN-gamma at this level. Neither cytokine treatment resulted in detectable levels of peptide-specific IL-4. Indirect evidence for the activity of Th2 cells in vivo came from the observation that IL-10 inhibited the primary PLP139-151-specific IgG2a and IgG3 response in favor of IgG1, whereas IL-4 inhibited the primary antibody response to the peptide, regardless of subclass. The combination of IL-4 and IL-10 did not affect the subclass composition. The observation that IL-10-treated mice remained sensitive to re-induction of EAE is not in support of an important role of Th2 cells in regulating disease activity in this model of actively induced EAE.
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PMID:IL-4 abrogates the inhibitory effect of IL-10 on the development of experimental allergic encephalomyelitis in SJL mice. 931 Aug 27


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