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)

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease in which peripheral lymphoid cells are activated by immunization with myelin proteins and become effector cells that traverse the central nervous system (CNS) capillaries and initiate inflammatory demyelinating lesions. The administration of transforming growth factor-beta (TGF-beta) has been shown previously to decrease the incidence and severity of EAE. In our studies we have determined: 1) the effects of TGF-beta injected at different intervals after the EAE-inducing immunization; 2) the effect of TGF-beta on the development of sensitized T cells, as assayed by the proliferative responses of T cells from lymph nodes and peripheral blood; 3) the extent of lymphoid cell infiltration in CNS of TGF-beta-treated and control mice; and 4) the role of endogenous TGF-beta and TNF in determining the severity of both acute and relapsing EAE. The onset of acute-EAE in SJL mice, induced by immunization with spinal cord homogenate in CFA and pertussigen, is on days 10 to 15. Although daily i.p. injections of 0.2 to 2 micrograms TGF-beta 1 or TGF-beta 2 on days 5 to 9 after immunization are highly protective, injections on days 1 to 5 or 9 to 13 are not. Moreover, anti-TGF-beta accelerates and aggrevates EAE when given on days 5 and 9, but not on day 12. Anti-TNF, injected on days 5 and 9, provides a comparable degree of protection as does TGF-beta. Similarly, in relapsing EAE, anti-TGF-beta increases, whereas anti-TNF decreases the incidence and severity of relapses. TGF-beta treatment on days 5 to 9 does not influence the appearance of sensitized cells in peripheral blood and lymph nodes, but does prevent the accumulation of T cells in brain and spinal cord, as assayed on days 15 to 20. It is concluded that the protective effect of TGF-beta is exerted at the level of the target organ, CNS and/or its vascular endothelium, rather than through a direct effect on lymphoid cells, and that there is a small window of 4 days in which TGF-beta exerts its protective effect.
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PMID:Studies on the mechanisms by which transforming growth factor-beta (TGF-beta) protects against allergic encephalomyelitis. Antagonism between TGF-beta and tumor necrosis factor. 833 93

We have examined the expression of factors associated with the growth, differentiation, and chemotaxis of cells of the monocyte/macrophage series in the central nervous system of Lewis rats sensitized to develop experimental allergic encephalomyelitis. CSF-1 mRNA increased significantly over that found in control animals (sensitized with OVA in CFA or CFA alone). The elevation in the levels of this growth factor commenced immediately before the onset of early clinical signs and peaked immediately before maximal clinical incidence of disease. Expression of CSF-1 message declined to base-line values with resolution of the disease process. CSF-1 protein was also detected in the central nervous system at the height of clinical disease. Expression of the receptor for CSF-1, the proto-oncogene c-fms, also paralleled the early disease process. Elevated levels of c-fms mRNA were detected immediately before the onset and peaked at the height of clinical signs of disease. In contrast to CSF-1 levels, elevated c-fms message expression persisted after resolution of the acute phase of experimental allergic encephalomyelitis. Levels of macrophage chemotactic factor-1 message were also elevated immediately before the onset of clinical signs, peaked with the height of clinical disease, and declined with resolution of the disease. Unlike CSF-1 or c-fms, no endogenous macrophage chemotactic factor-1 message was detected in control animals. Macrophage chemotactic factor-1 protein was demonstrated by Western blot in the central nervous system at the height of clinical disease. The results support the conclusion that expression of factors that specifically target cells of the monocyte/macrophage series are an important component of the disease process in experimental allergic encephalomyelitis.
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PMID:Expression of CSF-1, c-fms, and MCP-1 in the central nervous system of rats with experimental allergic encephalomyelitis. 845 Feb 28

Peripheral antigen-specific tolerance can be induced by feeding protein antigens. The mechanism has been described as either clonal anergy/deletion or induction of antigen-specific regulatory cells that produce transforming growth factor (TGF)-beta, depending on the dose of antigen fed. Experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis, can be prevented by feeding myelin basic protein (MBP) or proteolipid protein (PLP). We decided to address the role of chemokines in the induction of oral tolerance. We have used a model antigen system of feeding a high dose of human gamma globulin (HGG) to mice that have been subsequently immunized with HGG emulsified in CFA. The result was decreased recall proliferative, delayed-type hypersensitivity (DTH) and Th1 cytokine responses. By contrast, Th2 cytokine responses were enhanced. Interestingly, macrophage inflammatory protein (MIP)-1alpha production was decreased, whereas monocyte chemotactic protein (MCP)-1 production was enhanced. Induction of oral tolerance was prevented by the administration of anti-MCP-1 to mice fed HGG. These results show that chemokines play an important role in the induction of oral tolerance.
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PMID:The role of chemokines in oral tolerance. Abrogation of nonresponsiveness by treatment with antimonocyte chemotactic protein-1. 861 Sep 67

B7-1 and B7-2 are well characterized costimulatory ligands on Ag presentation cells for the CD28 and CTLA4 receptors on T cells. The fusion protein CTLA4Ig can block this interaction and prevent specific T cell activation. The development of fatal CD4+ T cell-mediated experimental allergic encephalomyelitis (EAE) in susceptible female Lewis rats was optimized by immunization with 20 mg of guinea pig spinal cord homogenate in CFA on day 0 with three doses of 1 microgram pertussis toxin given i.v. on days 0, 3, and 7. This immunization regimen uniformly resulted in the development of severe clinical neurologic signs of EAE with 100% mortality by day 17 postimmunization. Treatment with 0.5 mg/dose of rhCTLA4-Ig on days - 2, 0, 3, 6, 9, 12, 15 and 18 significantly decreased the incidence, delayed the onset, and reduced the severity of clinical EAE (p = 0.0002 vs control by the Mann-Whitney U test) enough to completely prevent fatal EAE, whereas treatment with control human IgG had no effect. Histologically, perivascular neutrophilic infiltrates were also dramatically decreased in the spinal cords of animals treated with CTLA4 but not in those treated with control human IgG. The proliferative response to encephalitogenic Ags (guinea pig myelin basic protein and proteolipid protein) by lymph node cells from animals immunized with guinea pig spinal cord 10 days before was also significantly suppressed in vitro by CTLA4Ig (1 microg/ml). However, the protective effect of CTLA4Ig could be completely prevented by the daily i.p. administration, from day 0 to 10, of exogenous human rIL-2 (180,000 IU). These results indicate a critical requirement of the costimulatory B7/CD28 pathway early in the development of CD4+ T cell-mediated EAE in the rat.
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PMID:Inhibition by CTLA4Ig of experimental allergic encephalomyelitis. 864 42

Activation of the vascular endothelium is important in the development of inflammation. Activated endothelial cells (EC) express surface markers not expressed by quiescent EC. These surface markers augment adhesion reactions and leukocyte migration. We examined microvessel EC activation longitudinally in experimental autoimmune encephalomyelitis (EAE) in Lewis rats. CNS microvessels were isolated at 0, 3, 7, 12, 20, and 30 days post-inoculation (PI). Normal and CFA-injected rat microvessels do not express activation antigens (Ag). Increased expression of major histocompatibility complex (MHC) class II molecule and intercellular adhesion molecule-1 (ICAM-1) were detected on CNS microvessels from immunized rats at 7 days PI, prior to development of clinical signs, and at 12 days PI. Enhanced MHC class I molecule was seen only at 12 days. MHC class II molecule expression was focally expressed along microvessel fragments. By 20 days PI, EC did not exhibit increased levels of any of the markers tested. Perivascular cells (possibly pericytes), however, were found to express MHC class II molecule and ICAM-1 up to 30 days PI. During the recovery phase isolated CNS microvessels from MBP-immunized rats were unresponsive to IFN gamma-mediated endothelial activation. Unresponsiveness was independent of IFN gamma concentration. These results suggest that the endothelium is restored to functional quiescence during the recovery phase of acute EAE.
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PMID:Recovery phase of acute experimental autoimmune encephalomyelitis in rats corresponds to development of endothelial cell unresponsiveness to interferon gamma activation. 872 61

Resistance to autoimmune encephalomyelitis was induced by s.c. infusion of myelin basic protein (MBP) in saline in combination with i.p. injections of anti-CD11a (LFA-1) mAbs. This treatment induces resistance to EAE induction, which appears early and persists for at least one month after treatment. Some MBP-CFA-challenged resistant rats showed minimal inflammation in the central nervous system, which was, however, confined to the meninges of the lower spinal cord. Examination of the immune status of MBP-anti-LFA-1 treated rats before encephalitogenic challenge failed to reveal any priming when assessed by Ag driven proliferation and cytokine production by lymphoid cells, and by circulating Ab production. Following challenge of protected rats, lymph node cell proliferation to MBP was unaltered, indicating that reactive cells had not been deleted or energized. Resistance could not be transferred with lymphoid cells from treated rats nor abrogated by cyclophosphamide treatment. In treated rats following challenge, there was a shift in the isotype of anti-MBP Ab produced, from an IgG2a:IgG1 ratio of 2:1 to 1:1, due to an increase in IgG1 production, indicating a possible bias towards a nonpathogenic Th2 CD4+ T cell response. The IgG1 Ab was detected early after challenge suggesting that pretreatment had indeed primed the animals, and had primed them to go down the Th2 pathway following encephalitogenic challenge. The ability to divert immune reactivity from a destructive to a nondestructive response could have important therapeutic implications for autoimmune disease.
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PMID:Short term treatment with soluble neuroantigen and anti-CD11a (LFA-1) protects rats against autoimmune encephalomyelitis: treatment abrogates autoimmune disease but not autoimmunity. 875 17

CD4+ T cells promote immune responses against foreign Ags while actively suppressing responses against self Ags. To address how CD4+ T cells ensure self-tolerance, we focused on two CD4+ T helper cells specific for myelin basic protein (MBP). GP2.E5/R1 T cells recognized rat MBP (RMBP) as a partial agonist and mediated mild experimental autoimmune encephalomyelitis (EAE), whereas R2 T cells recognized RMBP with full efficacy and mediated severe EAE. GP2.E5/R1 T cells were more susceptible to anergy induction than R2 T cells. Anergic GP2.E5/R1 T cells lacked proliferative reactivity, but expressed both I-A glycoproteins and high levels of radioresistant APC activity. During induction of anergy, these T cells acquired the ability to present MBP. In a separate subsequent culture without further addition of Ag, anergic GP2.E5/R1 T cells elicited full proliferative and IL-2 production responses by R2 T cells. Unlike activations induced via irradiated splenocytes, irradiated anergic T cells elicited anergy in R2 T cells in the form of a postactivational phase of nonresponsiveness. Anergic GP2.E5/R1 T cells not only transferred anergy to pathogenic R2 T cells in vitro, but these anergic T cells also transferred resistance to EAE in Lewis rats subsequently challenged with guinea pig MBP in CFA. Antagonistic signaling by autologous RMBP was more tolerogenic than that of guinea pig MBP in both in vitro and in vivo models of infectious anergy. We conclude that in the presence of tolerogenic mAb, antagonistic signaling by a self protein elicited the coordinate expression of anergy and T cell-mediated APC activity as a mechanism for the genesis and spread of infectious tolerance.
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PMID:Anergy-associated T cell antigen presentation. A mechanism of infectious tolerance in experimental autoimmune encephalomyelitis. 875 10

It has been shown that peripheral T cell tolerance can be induced by systemic antigen administration. We have been interested in using this phenomenon to develop antigen-specific immunotherapies for T cell-mediated autoimmune diseases. In patients with the demyelinating disease multiple sclerosis (MS), multiple potentially autoantigenic epitopes have been identified on the two major proteins of the myelin sheath, myelin basic protein (MBP) and proteolipid protein (PLP). To generate a tolerogenic protein for the therapy of patients with MS, we have produced a protein fusion between the 21.5-kD isoform of MBP (MBP21.5) and a genetically engineered form of PLP (deltaPLP4). In this report, we describe the effects of treatment with this agent (MP4) on clinical disease in a murine model of demyelinating disease, experimental autoimmune encephalomyelitis (EAE). Treatment of SJL/J mice with MP4 after induction of EAE either by active immunization or by adoptive transfer of activated T cells completely prevented subsequent clinical paralysis. Importantly, the administration of MP4 completely suppressed the development of EAE initiated by the cotransfer of both MBP- and PLP-activated T cells. Prevention of clinical disease after the intravenous injection of MP4 was paralleled by the formation of long-lived functional peptide-MHC complexes in vivo, as well as by a significant reduction in both MBP- and PLP-specific T cell proliferative responses. Mice treated with MP4 were resistant to disease when rechallenged with an encephalitogenic PLP peptide emulsified in CFA, indicating that MP4 administration had a prolonged effect in vivo. Administration of MP4 was also found to markedly ameliorate the course of established clinical disease. Finally, MP4 therapy was equally efficacious in mice defective in Fas expression. These results support the conclusion that MP4 protein is highly effective in suppressing disease caused by multiple neuroantigen epitopes in experimentally induced demyelinating disease.
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PMID:Treatment of experimental encephalomyelitis with a novel chimeric fusion protein of myelin basic protein and proteolipid protein. 883 9

We have developed a new model of generalized autoimmunity of the rat nervous system to study differential immunoregulation, barrier-function, and parenchymal inflammatory processes. We designed a multicomponent synthetic gene encoding major pathogenic determinants for Lewis rats of myelin basic protein (MBP), interphotoreceptor retinoid binding protein (IRBP), and P2 protein. Immunization with the recombinant protein induces a monophasic disease with inflammatory lesions in the eye, brain, spinal cord, and peripheral nerves. Rats recovered from GANS were tolerant against the induction of experimental autoimmune encephalomyelitis (EAE), neuritis (EAN), and uveoretinitis (EAU) by immunization with synthetic autoantigen-peptides/CFA. To demonstrate an application of GANS we have used a monoclonal antibody raised against encephalitogenic rat T lymphocytes. We show that this monoclonal antibody is suppressing not only inflammatory cell infiltration of brain and spinal cord, but as well of the eyes and the peripheral nervous system.
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PMID:Generalized autoimmunity of the nervous system (GANS) induced by a recombinant protein composed of major pathogenic determinants of MBP, IRBP, and P2 protein: suppression of inflammation by a monoclonal antibody against activated rat T line cells. 884 91

Injection of antigen cross-linked accessory cells has proven to be an efficient and highly selective approach for inducing epitope-specific peripheral tolerance. This approach has been used successfully to inhibit induction of experimental autoimmune encephalomyelitis (EAE) and to dissect the relative dominance of component encephalitogenic determinants that contribute to both acute and relapsing EAE. In this study, we evaluated the tolerogenic effect of the dominant encephalitogenic epitope for SJL/J mice, residues 139-151 of myelin proteolipid protein (PLP), on the induction and relapses of EAE induced actively with PLP139-151/CFA. Our results demonstrate the powerful protective effect of treating mice before induction of EASE with PLP139-151-conjugated splenocytes (SPL) on the incidence and severity of both the initial episode and the first relapse of EAE. Moreover, treatment of mice on the first day of onset of clinical signs of EAE reduced the severity of the first relapse, apparently by reducing T cell recognition of PLP139-151, although no significant therapeutic effect was observed during the initial treated clinical episode. These data demonstrate the utility of using neuroantigen-coupled accessory cells to prevent and treat relapsing EAE.
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PMID:Prevention and treatment of relapsing autoimmune encephalomyelitis with myelin peptide-coupled splenocytes. 887 3


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