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)

Lysosomal proteinases are increased in the tissue lesions of experimental allergic encephalomyelitis and have been implicated in the degradation of myelin proteins. The cellular origins of the increased proteinases are not known but reactive astrocytes found in areas of increased activity are candidate cells. To evaluate the potential of astrocytes as the source of these proteinases, cathepsin B (CB) and cathepsin D (CD) levels were measured in lysates of cultured astrocytes from neonatal rats. Because astrocytes are activated by inflammatory mediators in demyelinating lesions the effect of activation on proteinase levels was examined. Culture supernatants from mononuclear leukocytes stimulated with either concanavalin A or phytohemagglutinin (PHA) induced significant increases in the astrocytic proteinases. Neither PHA alone, interleukin-1, interleukin-2, nor gamma-interferon induced significant increases. Fractions of the supernatant from PHA stimulated mononuclear leukocytes were tested and activity was found in fractions corresponding to a molecular weight of 45-50,000. These studies demonstrate that astrocytes contain significant amounts of CB and CD activity which can be increased by a factor or factors released by activated mononuclear leukocytes.
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PMID:Activation of astrocytic lysosomal proteinases by factors released by mononuclear leukocytes. 271 Feb 77

The transforming growth factors TGF-beta 1 and beta 2 are cytokines with pronounced effects on leukocyte growth and function. To evaluate a potential use of these factors as immunosuppressive agents, we compared the effects of TGF-beta 1 and beta 2 on autoimmune T cells in rat inflammatory central nervous system disease, experimental allergic encephalomyelitis (EAE). We observed that both factors strongly inhibited in vitro activation of autoimmune T cells, suppressed the accumulation of interleukin-2 mRNA and decreased the expression of rat T cell activation antigens. In addition, cyclical changes in susceptibility to TGF-beta was observed with T line cells. The modulation of in vitro T cell function is associated with a considerable suppression of encephalitogenic capacity of autoimmune T line cells. Thus, TGF-beta 1 and beta 2 might have physiologic importance in limiting local T lymphocyte proliferation and effector function in autoimmune disease.
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PMID:Transforming growth factors beta 1 and beta 2: cytokines with identical immunosuppressive effects and a potential role in the regulation of autoimmune T cell function. 280 92

Cyclosporine is an 11 aminoacid cyclic peptide of fungal origin endowed with potent immunosuppressive activity. Unlike the conventional immunosuppressants, cyclosporine does not interfere with DNA metabolism, but it selectively and reversibly inhibits lymphocyte T-helper activation by inhibiting the production of interleukin-2 which plays a role in immune response development. Cyclosporine has little effect on lymphocytes B and does not modify the production of antibodies when it is in progress. The drug is effective in preventing spontaneous or autoantigen-induced auto-immune diseases in animals. The best studied models are experimental allergic encephalomyelitis, uveitis in the rat and spontaneous diabetes of BB rats. However, cyclosporine has no effect on diseases exclusively due to the pathogenic action of antibodies, such as spontaneous thyroiditis of the obese chicken. It is also possible to obtain a curative effect, this type of model being nearer to therapeutic conditions in humans than the previous models.
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PMID:[Cyclosporin and autoimmune diseases. 1: Experimental bases]. 355 Sep 87

Encounters with antigen can stimulate T cells to become activated and proliferate, become nonresponsive to antigen, or to die. T cell death was shown to be a physiological response to interleukin-2-stimulated cell cycling and T cell receptor reengagement at high antigen doses. This feedback regulatory mechanism attenuates the immune response by deleting a portion of newly dividing, antigen-reactive T cells. This mechanism deleted autoreactive T cells and abrogated the clinical and pathological signs of autoimmune encephalomyelitis in mice after repetitive administration of myelin basic protein.
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PMID:T cell deletion in high antigen dose therapy of autoimmune encephalomyelitis. 750 84

We previously reported that the CD4+ suppressor cells (Ts) that regulate recovery of Lewis rats from experimental autoimmune encephalomyelitis (EAE) produce transforming growth factor-beta (TGF-beta). We also reported that TGF-beta downregulates interferon-gamma (IFN-gamma), but not interleukin-2 (IL-2) production, by the CD4+ effector T cells (Te) that mediate EAE. We now report that TGF-beta also inhibits the production of tumor necrosis factor/lymphotoxin (TNF/LT) by EAE effector cells. When activated in vitro with myelin basic protein (MBP), Te produced TNF/LT, as measured using a WEHI 164 cytotoxicity assay. The specificity of cytokine action was demonstrated using neutralizing antibodies to TNF/LT. When added to the Te+MBP cultures, TGF-beta inhibited TNF/LT production in a dose-dependent fashion. Moreover, neutralizing anti-TGF-beta antibodies augmented TNF/LT production in the Te+MBP cultures. We also confirm that TGF-beta inhibits adoptive transfer of EAE. In contrast, murine IL-10 only partially inhibited TNF/LT and IFN-gamma production by Te. We conclude that TGF-beta production by Ts plays a major role in recovery from EAE in the Lewis rat by inhibiting TNF/LT and IFN-gamma production by the effector cells that mediate EAE.
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PMID:Transforming growth factor-beta 1 inhibits tumor necrosis factor-alpha/lymphotoxin production and adoptive transfer of disease by effector cells of autoimmune encephalomyelitis. 751 80

Copolymer-1 (Cop-1) inhibits the T cell response to myelin basic protein (MBP), suppresses experimental autoimmune encephalomyelitis in many animal species, and was recently shown to be effective in the treatment of multiple sclerosis (MS). Interferon beta-1b (IFN-beta), an immune modulator with no antigenic specificity, is already approved for treatment of relapsing-remitting MS. We investigated the combined effect of these two agents on the cellular immune response to MBP. Antigen-specific Th1-like cell lines were generated from two healthy individuals with different MHC phenotypes. Cop-1 inhibited the proliferation of all MBP-specific lines but had no suppressive effect on tuberculin (PPD) or tetanus toxoid (TT)-specific T cell lines from either donor, while IFN-beta non-specifically reduced proliferation of all T cell lines. When combined in vitro, Cop-1 and IFN-beta had additive suppressive effects on proliferation of MBP-specific T cell lines, with 70-100% inhibition depending on the concentration of antigen. Synthesis of the pro-inflammatory cytokines interleukin-2 and IFN-gamma by MBP-specific lines was also inhibited additively (up to 100%). When antigen-presenting cells (APC) were pretreated with Cop-1, IFN-beta or both, T cell proliferation was inhibited in the same additive pattern, even though the inhibitors were not present in culture, indicating that they acted primarily through modulation of APC function. Additive effects were not found with PPD- or TT-specific cell lines. Pretreatment of APC with IFN-beta resulted in dose-dependent reduction in HLA-DR and HLA-DQ expression, which paralleled inhibition of T cell proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Additive effects of copolymer-1 and interferon beta-1b on the immune response to myelin basic protein. 759 54

Our previous study using bromodeoxyuridine (BrdU) has shown that T cells in lesions of experimental autoimmune encephalomyelitis (EAE) in the rat central nervous system (CNS) lose their proliferating capability immediately after infiltration into the CNS. To characterize the nature of this phenomenon in more detail, we have isolated T cells from EAE lesions and examined their surface phenotype and response to encephalitogenic antigen, myelin basic protein (MBP). By flow cytometry (FCM) analysis, it was revealed that compared with peripheral blood lymphocytes, up-regulation of interleukin-2 (IL-2) receptors (0.06%-->3.73%) and the lymphocyte function-associated antigen-1 (LFA-1) molecules (0.76%-->17.6%) on spinal cord T cells (SCT) was observed. In spite of the latter finding suggesting that SCT are activated, SCT recovered from rats with full-blown EAE responded very poorly to MBP. The addition of thymocytes or thymocytes plus astrocytes did not alter the low responsiveness of SCT. More importantly, astrocytes strongly suppressed the response of lymph node T cells to MBP. Using MBP-specific T-line cells, it was revealed that T-cell suppression might be induced by incomplete presentation of MBP and release of suppressive humoral factors by astrocytes. Since the response of SCT was still poor when assayed after three and 12 rounds of stimulation with the antigen and propagation with IL-2, this phenomenon is long lasting. These findings are consistent with the findings obtained by the BrdU study that infiltrating T cells into the CNS do not proliferate vigorously. Taken together, the poor response of infiltrating T cells to MBP would be induced by co-existing cells such as astrocytes although the T cells are in an active form as judged by their surface phenotype. The present study suggests that activation of non-haematopoietic parenchymal cells in each organ by infiltrating T cells and subsequent inactivation of the T cells are important healing processes for organ-specific autoimmune diseases.
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PMID:In situ inactivation of infiltrating T cells in the central nervous system with autoimmune encephalomyelitis. The role of astrocytes. 769 23

Cytokine production by T cells in the cerebrospinal fluid (CSF) and central nervous system (CNS) of SJL/J mice during myelin basic protein (MBP)-induced experimental allergic encephalomyelitis (EAE) was examined. Reverse transcriptase/polymerase chain reaction (RT/PCR) was used to measure interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) mRNA levels from perfused CNS tissue (brain and spinal cord) and from cells isolated from CSF. Animals were grouped according to EAE severity, ranging from asymptomatic (adjuvant only) to severe disease (paralysis or severe paresis). Cytokine signals, normalized to actin, were almost undetectable in control tissues, and only slightly elevated in whole CNS tissue from animals with mild EAE. Both cytokine messages were strongly upregulated in CNS tissues derived from severely affected animals, consistent with previous observations correlating disease progression with infiltration by memory/effector CD4+ T cells, the major source of these cytokines. This cytokine upregulation was specific to the CNS, since other organs from the same animals did not express significant levels of IL-2 and IFN-gamma. CSF was obtained from the cisterna magna of unperfused mice and verified as such by absence of red blood cells (RBCs) and by immunoglobulin concentration orders of magnitude lower than in serum. Cytokine message was measured in RNA isolated from cells in CSF. Levels of IL-2 and IFN-gamma mRNA in CSF cells were significantly elevated in mild EAE and strongly upregulated in severe disease, correlating with those in total CNS tissue. These results confirm the CSF as representative of the immune status of the CNS and indicate a role for IL-2 and IFN-gamma in inflammatory CNS disease.
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PMID:Cytokine production by cells in cerebrospinal fluid during experimental allergic encephalomyelitis in SJL/J mice. 829 48

Suppressor T (Ts) hybridomas and interleukin-2-dependent T cell lines were established from spleens of mice, which had been rendered unresponsive to experimental allergic encephalomyelitis (EAE) either by mouse spinal cord homogenate or by the synthetic suppressant copolymer 1 (Cop 1). The Ts hybridoma supernatants and the Ts line cells specifically suppressed the in vitro response to the encephalitogenic myelin basic protein (BP), as indicated by inhibition of both the proliferation and interleukin-2-secretion responses of a BP-specific T cell line. Moreover, these Ts cells prevented the development of actively induced EAE in vivo. All hybridomas and lines were most effective when injected at the time of disease induction, thus suggesting that they operate as effector suppressor cells, and functionally inhibit encephalitogenic responses. The data presented here suggest that the suppressor cells are stimulated by the protective epitopes included in the BP as well as in the Cop 1 molecules and that they play an active role in the regulation of EAE. The generation of Ts lines and hybridomas, which have been induced by Cop 1, establish the specific stimulation of suppressor cells to EAE as a mechanism underlying the therapeutic activity of Cop 1.
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PMID:T suppressor hybridomas and interleukin-2-dependent lines induced by copolymer 1 or by spinal cord homogenate down-regulate experimental allergic encephalomyelitis. 841 68

We have recently reported that female Lewis rats exhibit significantly higher basal circadian levels of corticosterone (Cort) than male Lewis rats. The studies reported here were designed to explore whether male and female Lewis rats demonstrate a differential suppression of experimental autoimmune encephalomyelitis (EAE) following exposure to an identical regimen of repetitive restraint stress. Rats were restrained for 1 or 9 h/day beginning 5 days before myelin basic protein (MBP) challenge and extending through the recovery period (18 days post challenge). Both clinical signs and histopathological changes of EAE were more significantly suppressed in 9-h-stressed females relative to male Lewis rats. Investigation of the mechanism underlying the stress-induced suppression of EAE revealed that restraint stress did not alter the clinical course of EAE in rats challenged with MBP 68-88 encephalitogenic peptide, suggesting that restraint stress may affect processing and/or presentation of the MBP molecule. Stressed rats exhibited decreased interleukin-2 and interferon gamma production, and the frequency of MBP-reactive lymphocytes was reduced in comparison to non-stressed rats. Finally, repetitive restraint stress had no effect on blood-spinal cord permeability during EAE. The results presented here underscore the importance of such experimental variables as sex, strain, time of day, and the kinetics of immune response development.
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PMID:Suppression of experimental autoimmune encephalomyelitis by restraint stress: sex differences. 849 36


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