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)

We previously reported that recovery of Lewis rats from experimental autoimmune encephalomyelitis (EAE) is associated with the appearance of suppressor T cells (Ts). These Ts secrete TGF-beta which down-regulates the production of inflammatory cytokines by the effector T cells that mediate this disease. In the present study, we immunized Lewis rats with myelin basic protein (MBP)+CFA, and evaluated purified T cells and MBP-activated spleen cells (SpC) during the paralytic phase (day 12) and after recovery (days 30-33) for TGF-beta and interferon (IFN)-gamma mRNA. We used reverse transcriptase-polymerase chain reaction (RT-PCR), quantitated on the basis of beta-actin mRNA. Abundant IFN-gamma mRNA was present in MBP-activated SpC obtained on day 12. In contrast, only trace IFN-gamma mRNA was detected in day 30 activated SpC, and no IFN-gamma mRNA was present in purified, nonactivated T cells obtained at either time. The level of IFN-gamma mRNA correlated with secretion of IFN-gamma as determined by ELISA on SpC culture supernatants, and with severity of adoptively transferred EAE by the activated SpC. Thus, it appears that IFN-gamma mRNA is both transcribed and translated in response to antigen activation, resulting in secretion of IFN-gamma by the disease-inducing Te. In contrast, when we used RT-PCR to investigate the expression of TGF-beta mRNA, we found the transcript present in isolated T cells and MBP-activated SpC obtained from rats at both days 12 and 30. The presence of TGF-beta mRNA at time points corresponding to both clinical EAE and recovery suggests post-transcriptional regulation of the production of this immunoregulatory cytokine.
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PMID:Regulation of cytokine gene expression in experimental autoimmune encephalomyelitis. 895 Jul 3

Interferon regulatory factor-1 (IRF-1) is a transcription factor that regulates interferon-induced genes and type I interferons. Recently, studies of IRF-l-deficient mice have revealed that IRF-I regulates the induction of molecules that play important roles in inflammation, such as inducible nitric oxide synthase (iNOS) and interleukin-l beta-converting enzyme (ICE). To study the role of IRF-1 in autoimmunity, we investigated type II collagen-induced arthritis (CIA), and experimental allergic encephalomyelitis (EAE), in mice lacking IRF-1. The incidence and severity of CIA were significantly decreased in IRF-1-/- mice compared with IRF-l +/- mice, as was the production of interferon (IFN)-gamma in lymph node cells. Both IRF-l+/- and IRF-1-/- mice exhibited mild and transient disease after adoptive transfer of a type II collagen (CII)-specific T cell line together with sera from arthritic mice, but the IRF-1-/- mice were less severely affected than the IRF-1+/- mice. In addition, the incidence of EAE in IRF-1-/- mice was decreased as compared with IRF-1 +/- mice. Reverse transcription polymerase chain reaction showed that IRF-1 mRNA was constitutively expressed in the spinal cords of IRF-1+/- mice, and was upregulated in mice with clinical EAE. Expression of iNOS was also detected in inflamed spinal cords. These results suggest that IRF-I plays a key role in promoting inflammation and autoimmunity in CIA and EAE animal models.
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PMID:Reduced incidence and severity of antigen-induced autoimmune diseases in mice lacking interferon regulatory factor-1. 901 72

Variability in susceptibility to diseases is a well known phenomenon that has been attributed to genetic and environmental factors. At the level of the immune system, the reactivity of two types of T helper cells (Th1 and Th2 cells) plays an important role in determining disease susceptibility. Inflammatory (autoimmune) diseases are stimulated by cytokines produced by Th1 cells. Th2 cytokines stimulate antibody production (e.g., IgE) and eosinophilia as observed in allergic reactions or during parasitic infections. We describe here that the reactivity in a Th1 or a Th2 disease model significantly differs between individual rats that show group-specific differences in reactivity of the hypothalamic-pituitary-adrenal (HPA) axis, as well as in their behavioral responses to stress. We used two outbred lines of Wistar rats, apomorphine-susceptible rats that have a relatively hyperreactive HPA axis (APO-SUS) and apomorphine-unsusceptible rats that have a relatively hyporeactive HPA axis (APO-UNSUS). APO-SUS, but not APO-UNSUS, rats generated a vigorous, Th2-dependent IgE response after infection with the nematode Trichinella spiralis. In contrast, APO-UNSUS, but not APO-SUS, rats were susceptible for Th1-mediated experimental autoimmune encephalomyelitis. Investigation of cytokine responses of splenocytes revealed that the ratio of mRNA expression for Th1-derived interferon (IFN)-gamma and mRNA expression of Th2-derived interleukin-4 (IL-4) was significantly smaller in APO-SUS than in APO-UNSUS rats. In conclusion, individual differences in structure and reactivity of the neuroendocrine system co-occur with group-specific differences in susceptibility to inflammatory and infectious diseases.
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PMID:Apomorphine-susceptible and apomorphine-unsusceptible Wistar rats differ in their susceptibility to inflammatory and infectious diseases: a study on rats with group-specific differences in structure and reactivity of hypothalamic-pituitary-adrenal axis. 906 17

Although it is well established that CD40 and its ligand (CD40L) play pivotal roles in the development of humoral immunity, their roles in cell-mediated immunity and cell-mediated autoimmune diseases are not well defined. We report here that CD40:CD40L interaction is crucial for the development of experimental autoimmune encephalomyelitis (EAE), a prototype TH1-cell mediated autoimmune disease. Specific blockade of CD40L at the time of immunization markedly suppressed the incidence, mortality, day of onset, and clinical scores of EAE in (PLJ x SJL) F1 mice. Importantly, the disease suppression was not associated with anergy or deletion of autoreactive T cells but was accompanied by a drastic alteration of their cytokine profiles. The production of interferon (IFN)-gamma was markedly suppressed while that of interleukin (IL)-4 enhanced. These results suggest that CD40:CD40L interaction plays important roles in the differentiation of autoreactive TH1 versus TH2 cells in vivo, and that CD40L blockade is effective in preventing autoimmune encephalomyelitis.
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PMID:CD40L blockade prevents autoimmune encephalomyelitis and hampers TH1 but not TH2 pathway of T cell differentiation. 929 28

In experimental allergic encephalomyelitis (EAE), CD4+ T cells infiltrate the central nervous system (CNS). We derived CD4+ T cell lines from SJL/J mice that were specific for encephalitogenic myelin basic protein (MBP) peptides and produced both Th1 and Th2 cytokines. These lines transferred EAE to naive mice. Peptide-specific cells re-isolated from the CNS only produced Th1 cytokines, whereas T cells in the lymph nodes produced both Th1 and Th2 cytokines. Mononuclear cells isolated from the CNS, the majority of which were microglia, presented antigen to and stimulated MBP-specific T cell lines in vitro. Although CNS antigen-presenting cells (APC) supported increased production of interferon (IFN)-gamma mRNA by these T cells, there was no increase in the interleukin (IL)-4 signal, whereas splenic APC induced increases in both IFN-gamma and IL-4. mRNA for IL-12 (p40 subunit) was up-regulated in both infiltrating macrophages and resident microglia from mice with EAE. We have thus shown that a Th1 cytokine bias within the CNS can be induced by CNS APC, and that IL-12 is up-regulated in microglial cells within the CNS of mice with EAE. Microglia may therefore control Th1 cytokine responses within the CNS.
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PMID:The central nervous system environment controls effector CD4+ T cell cytokine profile in experimental allergic encephalomyelitis. 939 8

The progression of experimental allergic encephalomyelitis (EAE) in certain mouse strains has been reported to involve a broadening of the response to myelin antigens, apparently resulting from priming to endogenous determinants of the myelin sheath. The phenomenon has been termed determinant spread. Interest in this effect has centered on the mechanism it offers to explain the progressive, relapsing and remitting course of EAE and indeed of multiple sclerosis. We have conducted a systematic, longitudinal study in SJL mice to look for determinant spread during relapsing and remitting EAE, correlating epitope recognition and cytokine production with disease severity. Disease was induced using three of the four encephalitogenic proteolipid protein or myelin basic protein epitopes, and responses to each of four epitopes recognized by SJL T cells were tracked through acute disease, remission and relapse. The responses of lymph node cells, splenocytes and central nervous system (CNS)-infiltrating T cells were analyzed. While marginal, transient responses to secondary epitopes were detectable in splenocytes, CNS-infiltrating cells showed a dominant response to the original disease-inducing epitope without evidence of a shift to other determinants during relapse. Disease relapse was correlated with an increase in CNS-infiltrating cells and a high proliferative and interferon (IFN)-gamma response to the disease-inducing peptide. During remission, there was a decrease in numbers of cells infiltrating the CNS. These cells were down-regulated, showing low if any response to the myelin peptides tested as measured by proliferation, production of IFN-gamma or production of IL-4. Our findings argue strongly against a causal role for determinant spread in disease relapse as observed in these models of EAE.
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PMID:Relapsing and remitting experimental allergic encephalomyelitis: a focused response to the encephalitogenic peptide rather than epitope spread. 939 20

Alphaviruses infect neurons in the brain and spinal cord and cause acute encephalomyelitis in a variety of mammals. The outcome of infection is determined by whether the neurons survive infection and this, in turn, is determined by the virulence of the virus and the age of the host at the time of infection. We have been studying Sindbis virus (SV) infection of mice as a model system for alphavirus-induced encephalomyelitis. Investigation of intracerebral infection of weanling mice with two different strains of SV has allowed us to analyze the role of the immune response in protection from fatal disease (virulent NSV strain) and in clearance of virus from the nervous system during non-fatal disease (less virulent SV AR339 strain). Neutralizing and non-neutralizing antibodies to the E1 and E2 surface glycoproteins can protect mice from fatal NSV infection when given before or after infection, while T cells are not protective. The mechanism of antibody-mediated protection is not known, but it is likely that more than one mechanism is involved and that different mechanisms are involved in pre-infection and post-infection treatment protection. Clearance of infectious virus from the nervous system of mice during recovery from non-fatal disease is accomplished by antibodies to the E2 glycoprotein. The process does not involve damage to the infected neurons and is independent of complement and mononuclear cells. Bivalent antibody is required and binds to the surface of the infected cell. Initially, release of virus by budding from the cell surface is prevented and, subsequently, intracellular virus replication is inhibited possibly through antiviral mechanisms induced in co-operation with interferon. This non-lytic mechanism for control of virus infection results in the prolonged presence of viral RNA in tissue and the need for prolonged intrathecal synthesis of antiviral antibody by B cells within the central nervous system.
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PMID:The role of antibody in recovery from alphavirus encephalitis. 941 9

Oral tolerization with acetylcholine receptor (AChR) and myelin basic protein (MBP) prior to immunization with AChR+MBP+ complete Freund's adjuvant (CFA) alleviated clinical signs of experimental autoimmune myasthenia gravis (EAMG)+experimental allergic encephalomyelitis (EAE) and AChR- or MBP-specific T and B cell responses. Tolerance induced via the nasal route needs much less tolerogen and may still be as effective as oral tolerance induction. We now immunized Lewis rats with AChR+MBP+bovine peripheral nerve myelin (BPM)+CFA, which resulted in a multiphasic clinical picture with a combination of clinical signs of the EAMG+EAE+experimental allergic neuritis (EAN), accompanied by massive macrophage infiltrations in sections of muscle, spinal cord and sciatic nerve, and strong T and B cell responses to AChR, MBP and BPM in lymphoid organs. Nasal administration of microg doses of AChR+MBP+BPM prior to immunization with a mixture of these antigens+CFA effectively suppressed the incidence and severity of clinical disease, reduced macrophage infiltrations in sections of muscle, spinal cord and sciatic nerve, and down-regulated autoreactive T cell responses to the three antigens in lymphoid organs. Numbers of AChR-, MBP-, BPM-reactive Th1 type of cytokine interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha mRNA expression in lymph node cells were markedly suppressed, while transforming growth factor-beta (TGF-beta) mRNA expression was upregulated from nasally tolerized rats, suggesting an active suppression mechanism may act partly in the induction of tolerance. The results implicate the possibility to establish multiple autoantigen-based vaccination for the prevention of autoimmune diseases in humans.
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PMID:Nasal administration of multiple antigens suppresses experimental autoimmune myasthenia gravis, encephalomyelitis and neuritis. 956 16

We have previously shown that interferon-tau (IFN-tau) pretreatment inhibits the development of both acute and chronic mouse experimental allergic encephalomyelitis (EAE), an animal model for the human demyelinating disease multiple sclerosis (MS). IFN-tau is a type I IFN that has pregnancy recognition hormone activity in ruminants. Here we show that IFN-tau induced remission in SJL/J mice that had ongoing chronic active EAE disease and protected mice against secondary relapses. IFN-tau treatment reversed lymphocyte infiltration and microglial activation in the central nervous system. Mice that were treated with IFN-tau had lower levels of anti-MBP antibodies than untreated mice in both chronic and acute forms of EAE. MBP induced proliferation in B cells from EAE mice, but treatment with IFN-tau either in vivo or in vitro blocked activation. Furthermore, IFN-tau inhibited MBP activation of T cells from EAE mice. Thus, IFN-tau inhibits the humoral arm as well as the cellular arm of the autoimmune disease EAE. The data presented here show that IFN-tau inhibits both B cell and T cell responses in EAE as well as active, chronic EAE, and this may help explain the effectiveness of type I IFNs in treatment of MS.
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PMID:IFN-tau suppresses both the autoreactive humoral and cellular immune responses and induces stable remission in mice with chronic experimental allergic encephalomyelitis. 966 51

We previously observed Th1-dominated response in the central nervous system (CNS) of mice during the course of experimental allergic encephalomyelitis (EAE) with a semiquantitative reverse transcriptase-polymerase chain reaction (RT/PCR) analysis. We report here that mRNA levels for both inflammatory cytokines including interleukin (IL)-1beta, IL-2, IL-6, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha and TNF-beta and immunoregulatory cytokines including IL-4, IL-10 and transforming growth factor (TGF)-beta were up-regulated in the preclinical and/or acute phase but down-regulated in the recovery phase of EAE in lymph node (LN) of mice. Similar profiles for cytokine mRNA levels were also observed in spleen and peripheral blood mononuclear cells (PBMC). The present study also showed that a significant down-regulation of the mRNA level for IL-6 in the acute phase as compared with the preclinical phase, and a significant reduction of the mRNA level for TGF-beta in the preclinical and acute phase as compared with the corresponding mRNA levels in the control mice treated with complete Freund's adjuvant alone were characteristic in peripheral immune organs of mice with EAE. These results indicate that no particular bias in cytokine production occurred in peripheral immune organs of mice with actively induced relapsing EAE, and that the relative reduction in production of TGF-beta or IL-6 in peripheral circulation might participate in the induction or remission of EAE, respectively. Our results using the animal model of multiple sclerosis (MS) suggested that the mRNA levels for IL-6 and TGF-beta in PBMC from patients with MS may be a good indicator to assess the disease activity or to predict relapse.
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PMID:The pattern of cytokine gene expression in lymphoid organs and peripheral blood mononuclear cells of mice with experimental allergic encephalomyelitis. 967 Aug 56


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