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)

By 24 h after mechanical trauma to the cerebral cortex, astroglial reaction begins and injury sites are infiltrated by activated mononuclear phagocytes derived from blood-borne monocytes and endogenous microglia. There is little information about cellular interactions between astrocytes and leukocytes during this process. We previously showed that murine astrocytes produce chemokines including monocyte chemoattractant protein-1 (MCP-1) during experimental autoimmune encephalomyelitis. In this study, we asked whether astrocytes produce MCP-1 in the absence of immune mediated inflammation. To address this question, we analyzed the time course and cellular source of MCP-1 in mouse brain after penetrating mechanical injury, with particular focus on early time points before histologic detection of infiltrating mononuclear phagocytes. We observed sharply increased steady state levels of MCP-1 mRNA within 3 h after nitrocellulose membrane stab or implant injury to the adult mouse brain, and MCP-1 protein elevations were documented at 12 h postinjury. In situ hybridization combined with immunohistochemistry for the glial fibrillary acidic protein astrocyte marker showed that astrocytes were the cellular source of MCP-1 mRNA at these early time points after mechanical brain injury. Stab injury to the neonatal brain evoked neither MCP-1 expression nor astrogliosis. These results demonstrate that chemokine gene expression comprises one component of the astrocyte activation program. The data are consistent with a role for MCP-1 in the central nervous system inflammatory response to trauma.
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PMID:Chemokine monocyte chemoattractant protein-1 is expressed by astrocytes after mechanical injury to the brain. 866 8

Central nervous system (CNS) expression of two chemokine mRNAs, encoding monocyte chemoattractant protein-1 (MCP-1) and IFN-gamma-inducible protein (IP-10), was previously shown to be closely related to the onset of clinical signs of murine experimental autoimmune encephalomyelitis (EAE). Chemokine mRNAs accumulated in a striking, transient burst within astrocytes, near inflammatory leukocyte infiltrates. It remained unclear if chemokines functioned to initiate leukocyte entry into CNS tissues, or to amplify the intrathecal inflammatory reaction. To address this issue, we determined the expression of chemokine mRNAs at the earliest evidence of CNS immune-mediated inflammation. For these experiments, mice were sacrificed in pairs at varying times after immunization. Only one member of each pair was symptomatic for EAE at the time of sacrifice. Symptom presence correlated well with histological inflammation at the time of sacrifice. RNA was prepared from two CNS sites, brain and spinal cord, and expression of chemokine mRNAs was analyzed by a sensitive and quantitative reverse transcriptase/polymerase chain reaction dot-blot hybridization assay. CNS expressions of MCP-1 and IP-10 gene were correlated tightly with histological inflammation; indeed, chemokine expression was never detected in the absence of leukocyte infiltrates. In situ hybridizations showed that astrocytes expressed chemokine transcripts. These findings provide new information about mechanisms controlling chemokine mRNA expression during immune-mediated inflammation in EAE and are consistent with a role for chemokines as amplifiers of CNS inflammatory reactions.
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PMID:Central nervous system chemokine mRNA accumulation follows initial leukocyte entry at the onset of acute murine experimental autoimmune encephalomyelitis. 890 49

Chemokines are secreted peptides that exhibit selective chemoattractant properties for target leukocytes. Two subfamilies, alpha- and beta-chemokines, have been described, based on structural, genetic, and functional considerations. In acute experimental autoimmune encephalomyelitis (EAE), chemokines are up-regulated systemically and in central nervous system (CNS) tissues at disease onset. Functional significance of this expression was supported by other studies; intervention with an antichemokine antibody abrogated passive transfer of EAE, and chemokines expressed in brains of transgenic mice recruited appropriate leukocyte populations into the CNS compartment. Chemokine expression in the more relevant circumstance of chronic EAE has not been addressed. We monitored the time course and cellular sources of chemokines (monocyte chemoattractant protein-1, macrophage inflammatory protein-1 alpha, interferon-gamma-inducible protein of 10 kd, KC, and regulated on activation, normal T-cell expressed and secreted cytokine) in CNS and peripheral tissues during spontaneous relapses of chronic EAE. We found coordinate chemokine up-regulation in brain and spinal cord during clinical relapse, with expression confined to CNS tissues. Monocyte chemoattractant protein-1, interferon-gamma-inducible protein of 10 kd, and KC were synthesized by astrocytic cells, whereas macrophage inflammatory protein-1 alpha and regulated on activation, normal T-cell expressed and secreted cytokine were elaborated by infiltrating leukocytes. The results demonstrate stringent regulation of multiple chemokines in vivo during a complex organ-specific autoimmune disease. We propose that chemokine expression links T-cell antigen recognition and activation to subsequent CNS inflammatory pathology in chronic relapsing EAE.
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PMID:Synchronous synthesis of alpha- and beta-chemokines by cells of diverse lineage in the central nervous system of mice with relapses of chronic experimental autoimmune encephalomyelitis. 903 75

Regulation of the immune response is critical to homeostasis. While innate immunity can influence the development of adaptive immune responses, its role in regulation is less well understood. Recently, NK cells have been implicated in the control of experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. In this report, we show that rat bone marrow-derived NK cells exhibited potent inhibitory effects on T cell proliferation to both Con A as well as the central nervous system Ag myelin basic protein. There was also a significant decrease in both IFN-gamma and IL-10 production in vitro, whereas levels of the beta-chemokine monocyte chemoattractant protein-1 were significantly elevated. Flow cytometry studies suggest that the NK cells may play an important role in regulating both normal and autoimmune T cell responses by exerting a direct effect on activated, autoantigen-specific T cells.
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PMID:Inhibition of autoimmune T cell responses in the DA rat by bone marrow-derived NK cells in vitro: implications for autoimmunity. 1041 39

Experimental autoimmune encephalomyelitis (EAE) is a demyelinating disease of the central nervous system (CNS) that is a model for multiple sclerosis. Previously, we showed that depletion of gamma delta T cells significantly reduced clinical and pathological signs of disease, which was associated with reduced expression of IL-1 beta, IL-6, TNF-alpha, and lymphotoxin at disease onset and a more persistent reduction in IFN-gamma. In this study, we analyzed the effect of gamma delta T cell depletion on chemokine and chemokine receptor expression. In the CNS of control EAE mice, mRNAs for RANTES, eotaxin, macrophage-inflammatory protein (MIP)-1 alpha, MIP-1 beta, MIP-2, inducible protein-10, and monocyte chemoattractant protein-1 were detected at disease onset, increased as disease progressed, and fell as clinical signs improved. In gamma delta T cell-depleted animals, all of the chemokine mRNAs were reduced at disease onset; but at the height of disease, expression was variable and showed no differences from control animals. mRNA levels then fell in parallel with control EAE mice. ELISA data confirmed reduced expression of MIP-1 alpha and monocyte chemoattractant protein-1 at disease onset in gamma delta T cell-depleted mice, and total T cell numbers were also reduced. In normal CNS mRNAs for CCR1, CCR3, and CCR5 were observed, and these were elevated in EAE animals. mRNAs for CCR2 were also detected in the CNS of affected mice. Depletion of gamma delta T cells reduced expression of CCR1 and CCR5 at disease onset only. We conclude that gamma delta T cells contribute to the development of EAE by promoting an inflammatory environment that serves to accelerate the inflammatory process in the CNS.
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PMID:Experimental autoimmune encephalomyelitis on the SJL mouse: effect of gamma delta T cell depletion on chemokine and chemokine receptor expression in the central nervous system. 1065 66

The perivascular transmigration and accumulation of macrophages and T lymphocytes in the CNS of mice with experimental autoimmune encephalomyelitis (EAE) may be partly regulated by low m.w. chemotactic cytokines. Using the RNase protection assay and ELISA, we quantified expression of chemokines and chemokine receptors in the spinal cord (SC), brain, and lymph nodes of BV8S2 transgenic mice that developed or were protected from EAE by vaccination with BV8S2 protein. In paralyzed control mice, the SC had increased cellular infiltration and strong expression of the chemokines RANTES, IFN-inducible 10-kDa protein, and monocyte chemoattractant protein-1 and the cognate chemokine receptors CCR1, CCR2, and CCR5, with lower expression of macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta, and MIP-2; whereas brain had less infiltration and a lower expression of a different pattern of chemokines and receptors. In TCR-protected mice, there was a decrease in the number of inflammatory cells in both SC and brain. In SC, the reduced cellular infiltrate afforded by TCR vaccination was commensurate with profoundly reduced expression of chemokines and their cognate chemokine receptors. In brain, however, TCR vaccination did not produce significant changes in chemokine expression but resulted in an increased expression of CCR3 and CCR4 usually associated with Th2 cells. In contrast to CNS, lymph nodes of protected mice had a significant increase in expression of MIP-2 and MIP-1beta but no change in expression of chemokine receptors. These results demonstrate that TCR vaccination results in selective reduction of inflammatory chemokines and chemokine receptors in SC, the target organ most affected during EAE.
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PMID:Reduced chemokine and chemokine receptor expression in spinal cords of TCR BV8S2 transgenic mice protected against experimental autoimmune encephalomyelitis with BV8S2 protein. 1072 56

Pro-inflammatory cytokines play a crucial role in the regulatory and effector phase of the immune-mediated mechanism sustaining multiple sclerosis pathogenesis (MS) thus supporting the use of anti-inflammatory cytokines as a therapeutic option. Systemic administration of cytokines shows, however, limited therapeutic efficacy and undesirable/unpredictable side-effects. We have developed a non-toxic system to deliver cytokines within the central nervous system (CNS) based on the intrathecal (i.c.) administration of non-replicative herpes simplex (HSV) type-1-derived viral vectors engineered with heterologous cytokine genes. Compared to controls, mice affected by experimental autoimmune encephalomyelitis (EAE) and i.c. injected with an HSV-1-derived vector containing the gene of the anti-inflammatory cytokine IL-4 showed a significant amelioration of clinical and pathological EAE signs. A decreased mRNA expression of the monocyte chemoattractant protein-1 (MCP-1) by mononuclear CNS-infiltrating cells was also observed. Peripheral T cells from IL-4-treated mice were not affected both in their antigen-specific proliferative response and in the cytokine secretion pattern. Our results indicate that CNS cytokine delivery with HSV-1-derived vectors is a feasible therapeutic strategy and might represent an alternative approach for the treatment of immune-mediated demyelinating diseases. Advantages of this approach over systemic cytokine administration are the high cytokine level reached within the CNS and the absence of side-effects on the peripheral immune system. The short-lasting cytokine production in the CNS after a single vector administration (4 weeks) is the limiting factor of this novel technology which, although promising, has to be improved.
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PMID:Cytokine therapy in immune-mediated demyelinating diseases of the central nervous system: a novel gene therapy approach. 1085 55

We recently used a modification of gene therapy (naked DNA vaccination) to induce immunological memory against self-pro-inflammatory chemokines such as macrophage inflammatory protein-1 alpha or monocyte chemoattractant protein-1, and against the pro-inflammatory cytokine tumor necrosis factor-alpha. First, DNA constructs encoding each of the different pro-inflammatory mediators together with a repeated immunostimulatory sequence were prepared. Then, experiment animals were subjected to a repeated administration of each construct. Under these conditions, tolerance to the product of each insert was broken, and immunological memory established. Upon induction of experimental autoimmune encephalomyelitis, a T cell-mediated autoimmune disease of the central nervous system that serves as a model for multiple sclerosis or adjuvant induced arthritis, this memory was "turned on" to provide DNA-vaccinated animals a high state of disease resistance. Antibodies to the product of each inserted gene were isolated form these animals. Each antibody was found capable of neutralizing in vitro the chemoattractive properties of each relevant chemokine, thereby transferring disease resistance. Interestingly, the level of their production was dependent on disease severity, that is, each titer was accelerated in accordance with disease progression. Thus, by using a simple gene therapy technique the immune system could be "re-educated" to restrain its own harmful activities.
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PMID:Gene therapy for T cell-mediated autoimmunity: teaching the immune system how to restrain its own harmful activities by targeted DNA vaccines. 1090 20

We have shown that macrophages and microglia present within demyelinating plaques of patients with multiple sclerosis (MS) are immunoreactive for the chemokine receptor CCR1 and its ligand, macrophage inflammatory protein-1alpha. To test the importance of CCR1 to the pathogenesis of MS, we studied the progression of experimental allergic encephalomyelitis (EAE) in CCR1(+/+) vs. CCR1(-/-) mice. After immunization with myelin oligodendrocyte glycoprotein (MOG) 35-55 peptide, nearly all CCR1(+/+) mice developed EAE (95% incidence, severity 2.5+/-0.1), whereas CCR1(-/-) mice had less severe disease (55% incidence, p<0.001; severity 1. 2+/-0.2, p<0.001). CCR1(+/+) mice showed elevated brain mRNA for the chemokines immune protein (IP)-10, RANTES and monocyte chemoattractant protein-1 prior to disease onset, whereas only IP-10 mRNA was elevated in CCR1(-/-) mice. Both groups of mice had comparable in vitro lymphocyte proliferation and cytokine production upon stimulation with MOG peptide, and similar cutaneous hypersensitivity responses to 2,4-dinitrofluorobenzene, suggesting that CCR1(-/-) mice were not systemically immunosuppressed. These data demonstrate that deletion of a chemokine receptor is at least partially protective in EAE, and suggest that targeting of CCR1 may be of therapeutic significance clinically.
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PMID:Leukocyte recruitment during onset of experimental allergic encephalomyelitis is CCR1 dependent. 1094 Sep 28

Astrocytes are specialized cells of the CNS that are implicated in the pathogenesis of multiple sclerosis and experimental allergic encephalomyelitis. In acute and relapsing-remitting experimental allergic encephalomyelitis, the neutrophil chemoattractant CXC chemokines macrophage-inflammatory protein (MIP)-2 and KC are associated with reactive astrocytes in the parenchyma. In vitro treatment of primary astrocyte cultures with nanomolar concentrations of MIP-2 or KC markedly up-regulated expression of the monocyte/T cell chemoattractants monocyte chemoattractant protein-1, inflammatory protein-10, and RANTES by a mechanism that includes stabilization of mRNA. Production of TNF-alpha and IL-6 transcripts were also noted, as was autocrine induction of MIP-2 and KC message. In addition, low levels of MIP-1alpha and MIP-1beta were induced following treatment with MIP-2 or KC. These effects are specific to astrocytes as MIP-2 treatment of microglial cells failed to elicit chemokine production. The astrocyte chemokine receptor for MIP-2 has 2.5 nM affinity for ligand. Astrocytes from CXCR2-deficient mice still respond to KC and MIP-2, indicating the presence of an alternative or novel high affinity receptor for these ligands. We propose that this KC/MIP-2 chemokine cascade may contribute to the persistence of mononuclear cell infiltration in demyelinating autoimmune diseases.
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PMID:Macrophage inflammatory protein-2 and KC induce chemokine production by mouse astrocytes. 1103 12


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