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 have recently shown that apoptosis, an active process of cellular self-destruction, occurs in the central nervous system in Lewis rats with acute experimental autoimmune encephalomyelitis (EAE) induced by inoculation with myelin basic protein (MBP) and adjuvants. Conventional light and electron microscopic studies suggested that some of the apoptotic cells were oligodendrocytes and that others were hematogenous mononuclear cells. To determine whether any of the apoptotic cells were T lymphocytes, we used the technique of pre-embedding immunolabelling which allows sufficient preservation of the ultrastructure to permit recognition of apoptotic changes while at the same time preserving surface antigens so that the identity of the apoptotic cells can be determined by immunocytochemistry. Light microscopic immunocytochemistry using the monoclonal antibodies OX-34 (CD2) and R73 (alpha beta T-cell receptor) revealed that 10% of the CD2+ cells and 5% of the alpha beta T lymphocytes in the parenchyma of the spinal cord were dying by apoptosis. The presence of apoptotic alpha beta T cells was confirmed by electron microscopy. About half of all the apoptotic cells within the spinal cord were labelled by these antibodies. It is possible that some of the unlabelled apoptotic cells were also T lymphocytes but that others were glial cells such as oligodendrocytes. One possible interpretation of this T-cell apoptosis is that it represents activation-induced cell death, which has recently been shown to provide a mechanism of clonal elimination of mature as well as immature autoreactive T cells. Another possible interpretation is that it is a result of corticosterone released during the course of EAE. The apoptotic elimination of target-antigen-specific lymphocytes within the target organ in this autoimmune disease may contribute to the subsidence of inflammation and, if ongoing, to the development of tolerance.
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PMID:Apoptosis of alpha beta T lymphocytes in the nervous system in experimental autoimmune encephalomyelitis: its possible implications for recovery and acquired tolerance. 138 26

Experimental allergic encephalomyelitis (EAE) is an autoimmune demyelinating disease of the central nervous system (CNS). EAE can be induced by immunization with myelin basic protein (MBP) or passive transfer of MBP-reactive T cell lines and clones. We established several T-cell clones from SJL/J mice by immunization with whole rat MBP or a synthetic peptide encompassing guinea pig MBP 89-101 which contains the encephalitogenic determinant for SJL/J mice. One clone was found to have lost its encephalitogenicity during long-term passages in vitro, although this clone maintains its specific reactivity to the encephalitogenic determinant. To clarify the difference between the encephalitogenic T cell clone (4b. 14a) and the non-encephalitogenic T-cell clone (4b. 14a/n), we examined the suppressive activity of 4b. 14a/n on the reactivity to antigen of 4b. 14a, various lymphokine production and adhesion molecules expression of 4b. 14a and 4b. 14a/n. The culture fluid of the both 4b. 14a/n and 4b. 14a revealed a suppressive effect on the proliferation of 4b. 14a stimulated by MBP 89-101, and the effect was not different between these clones. In lymphokine production, the activities of lymphotoxin, interferon or interleukin-2 were not different between encephalitogenic clones (4b.14a and TNT-1) and 4b. 14a/n, whereas the activity of tumor necrosis factor-alpha, passively secreted by antigen presenting cell, was higher in culture media of 4b. 14a/n. Examination of adhesion molecule expression of 4b.14a/n failed to show any differences in expression of lymphocyte function-associated antigen-1 (LFA-1) alpha and CD2 in the comparison with 4b. 14a. However, LFA-1 beta expression of 4b. 14a/n was always less than of 4b. 14a. The present studies indicated that the lack of encephalitogenicity of T-cell clones which were responsive to an encephalitogenic determinant depends not on the difference in major lymphokines production but partially on adhesion molecules expression which was decreased in non-encephalitogenic T-cell clone.
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PMID:[Experimental allergic encephalomyelitis: immunopathological analysis of antigenic reactivity and loss of encephalitogenicity]. 138 88

We reported previously that two different anti-CD4 monoclonal antibodies (W3/25, MRC OX35) were effective in treating experimental allergic encephalomyelitis in the Lewis rat whereas anti-I-A antibody was ineffective. Further studies with other monoclonal antibodies and fragments have now been performed. Anti-I-E antibody was ineffective in shortening the disease duration even when used in combination with anti-I-A antibody. Anti-CD2 (T11) antibody was marginally effective, shortening the duration of disease by only one day on the average. Combination of anti-CD4 antibody with anti-CD2 antibody did not improve the recovery time over the use of anti-CD4 antibody alone. On the other hand, the F (ab')2 fragment of the anti-CD4 antibody was as effective in the treatment of disease as the intact antibody molecule, indicating that it was sufficient to block the CD4 molecules on the cell surface of the EAE effector cells in order to affect the disease course.
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PMID:Treatment of clinical experimental allergic encephalomyelitis in the rat using fragments and combinations of monoclonal antibodies. 325 18

Using murine monoclonal antibodies to mark total T cells, we have found rapid migration of T cells into the CSF in progressive multiple sclerosis patients, suggesting that the ongoing inflammatory responses in the CNS may depend on the continued movement of cells from the periphery into the target organ. Cloning experiments have indicated that the T cells present in the CSF during viral and post-viral encephalomyelitis represent sequestered populations of antigen-specific cells. In more chronic disease processes, these cells may also have restricted clonality as measured by the frequency of different T-cell receptor gene rearrangements on Southern blotting. It is known that there is restricted clonality of the B-cell immunoglobulin response in the CSF compartment with inflammatory CNS diseases, and with infections the majority of these so-called oligoclonal antibodies are directed against the exciting antigen and are synthesized in the CNS. Although we believe that T cells in the CNS originate from the blood, during the course of an inflammatory response the antigen and clonally-restricted populations found in the CSF may represent either selective migration or selective accumulation in the CNS. Selective migration might occur at the endothelial barrier as these cells can express Class II MHC antigens and act as antigen-presenting cells in the CNS (McCarron et al. 1985). Selective accumulation of T cells in the CNS might occur after non-specific migration of cells into the CNS followed by proliferation and expansion of T cells that have been induced by antigens in the brain. Antigen-presenting cells that are present in situ, such as astrocytes, may also play a role in the selective expansion of T cells in the CSF (Fontana et al. 1984). Alternatively, it is possible that T cells are induced to expand in the target CNS tissue non-specifically, e.g., via the CD2 pathway. In this regard, we have observed that CSF T cells exhibit alterations in stimulation by anti-T112 + anti-T113 monoclonal antibodies. The mechanism of damage to CNS tissue by immune cells is essentially unknown. For example there are no clear links between antibodies present in the CNS and CNS damage in SSPE where high titers of anti-measles antibodies are present. Whereas we did not observe high frequencies of measles-reactive cells in the CSF of a subject with SSPE, we did observe MHC non-restricted cytotoxic T cells which expressed TCR-gamma chains rather than alpha-beta chains.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:T cells in multiple sclerosis and inflammatory central nervous system diseases. 332 24

To identify an effective immunotherapy for T-cell-mediated autoimmune diseases, prevention and treatment of experimental autoimmune encephalomyelitis (EAE) induced in Lewis rats was attempted by administering a monoclonal antibody (mAb), R73, which is specific for rat T-cell receptor (TcR) alpha beta. Short-term administration of R73 at relatively low doses before immunization with encephalitogenic antigen, myelin basic protein (MBP), prevented the development of EAE. However, treatment with anti-CD4 and anti-Ia mAb in the same protocol was ineffective. Flow cytometric analysis demonstrated that short-term administration of R73 resulted in transient down-regulation of the TcR molecules, whereas the number of CD2-expressing T cells was well preserved. Furthermore, the response to MBP of T cells isolated from rats that were pretreated with R73 and then immunized with MBP was strongly suppressed. On the other hand, the T-cell response of R73-pretreated rats to a third-party antigen which was immunized at a later period was not inhibited. These findings suggest that in vivo administration of a low dose of R73 protects rats from EAE by inducing anergy of MBP-reactive encephalitogenic T cells. Furthermore, R73 treatment which started on day 10 of the immunization (shortly before the day of onset of clinical signs) completely suppressed the induction of EAE and that which started on day 11 (the day of onset) hastened recovery. Since the phenotypes of the TcR V beta chain of encephalitogenic T cells are not so limited as previously believed, immunotherapy with mAb against the TcR alpha beta framework may be one of the best methods for treatment of T-cell-mediated autoimmune diseases.
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PMID:Successful prevention and treatment of autoimmune encephalomyelitis by short-term administration of anti-T-cell receptor alpha beta antibody. 751 Jun 61

The immunotherapeutic potential of three anti-rat CD2 monoclonal antibodies (mAb) (OX34, OX54, OX55) and the combination of OX54 with OX55 was tested in Lewis rat experimental autoimmune encephalomyelitis (EAE). In actively induced EAE, a single injection of OX34 2 days before immunization with myelin basic protein (MBP) in complete Freund's adjuvant (CFA) completely prevented or greatly attenuated EAE in all animals. Injection of OX54 acted moderately suppressive while OX55 or OX54/55 did not affect disease severity. Abrogation of EAE by OX34 was not restricted to its application before immunization. Therapeutic administration of all three mAb and the Ab combination from onset of first clinical signs efficiently blocked progression of disease and prevented all animals from developing hind limb paresis. In adoptive transfer EAE induced with in vitro activated cells of an encephalitogenic T helper line, clinical and histological signs were completely prevented by injection of OX34 on the day of cell transfer and 4 days later, underlining the strong impact of anti-CD2 mAb on the effector phase of disease. Immunocytofluorometric analysis of peripheral blood lymphocytes after a single Ab injection demonstrated that all mAb induced a variable degree of transient reduction in T cell numbers and modulation of CD2 antigens. In contrast to the other mAb, OX34 persisted on lymphocytes for at least 11 days, which may explain its unique suppressive effect on EAE after a single injection before immunization. The assumption that prophylactic administration of OX34 also inhibits MBP-induced EAE, due to persistence into the effector phase, was substantiated by the finding that none of the mAb prevented generation of an antigen-specific cellular response in MBP/CFA-immunized animals. Since none of the Ab induced T cell unresponsiveness or inhibited T cell activation by antigen- or Ab-mediated stimulation of the T cell receptor, we suggest that their marked action on the effector phase of EAE may rely on inhibition of T cell infiltration into the central nervous system. The demonstrated efficacy of these anti-CD2 mAb in EAE suggests a potential therapeutic role that may be equal to that of anti-CD4 or anti-T cell receptor Ab.
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PMID:Suppression of experimental autoimmune encephalomyelitis in Lewis rats by antibodies against CD2. 753 58

Since calcium activated neutral proteinase (calpain) is present in the central nervous system (CNS) and degrades myelin proteins, this endopeptidase has been suggested to play a role in myelin destruction in demyelinating diseases such as multiple sclerosis (MS). In the present study, calpain immunocytochemical expression was examined in Lewis rats with acute experimental allergic encephalomyelitis (EAE), an animal model for MS and optic neuritis. To identify cells expressing calpain, we labeled rat optic nerve sections for calpain with a polyclonal myelin calpain antibody and with monoclonal antibodies for glial (GFAP, OX42) and inflammatory (CD2, ED2, ED1, IFN-gamma) cell-specific markers. The results showed increased calpain expression in microglia (OX42) and infiltrating macrophages (ED1,2) in EAE compared to normal controls. Astrocytes constitutively expressed calpain in controls and acute EAE. Reactive astrocytes in EAE located in or near inflammatory foci, exhibited markedly increased calpain expression. Most T cells in acute EAE showed low level calpain expression while activated IFN-gamma-producing lymphocytes in inflammatory foci exhibited elevated levels of calpain expression. Thus, our results demonstrate increased calpain expression (at transcriptional and/or translational levels) in a rat model of optic neuritis. A role for calpain in myelin destruction during optic neuritis may be relevant to the pathogenesis of this disorder.
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PMID:Increased calpain expression in experimental demyelinating optic neuritis: an immunocytochemical study. 951 58

In demyelinating diseases such as multiple sclerosis (MS), myelin membrane structure is destabilized as myelin proteins are lost. Calcium-activated neutral proteinase (calpain) is believed to participate in myelin protein degradation because known calpain substrates [myelin basic protein (MBP); myelin-associated glycoprotein] are degraded in this disease. In exploring the role of calpain in demyelinating diseases, we examined calpain expression in Lewis rats with acute experimental allergic encephalomyelitis (EAE), an animal model for MS. Using double-immunofluorescence labeling to identify cells expressing calpain, we labeled rat spinal cord sections for calpain with a polyclonal millicalpain antibody and with mAbs for glial (GFAP, OX42, GalC) and inflammatory (CD2, ED2, interferon gamma) cell-specific markers. Calpain expression was increased in activated microglia (OX42) and infiltrating macrophages (ED2) compared with controls. Oligodendrocytes (galactocerebroside) and astrocytes (GFAP) had constitutive calpain expression in normal spinal cords whereas reactive astrocytes in spinal cords from animals with EAE exhibited markedly increased calpain levels compared with astrocytes in adjuvant controls. Oligodendrocytes in spinal cords from rats with EAE expressed increased calpain levels in some areas, but overall the increases in calpain expression were small. Most T cells in grade 4 EAE expressed low levels of calpain, but interferon gamma-positive cells demonstrated markedly increased calpain expression. These findings suggest that increased levels of calpain in activated glial and inflammatory cells in EAE may contribute to myelin destruction in demyelinating diseases such as MS.
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PMID:Increased calpain expression in activated glial and inflammatory cells in experimental allergic encephalomyelitis. 957 59

The CD28 co-stimulatory pathway is well established for T cell activation; however, results from CD28 -/- mice suggest the existence of additional co-stimulatory pathways. Here we report the further characterization of a new member of the CD2 superfamily, NTB-A, important in T cell co-stimulation. NTB-A is expressed on T cells, and its expression is up-regulated on activated cells. Triggering of NTB-A with monoclonal antibodies in the absence of CD28 signals leads to T cell proliferation and interferon-gamma secretion but not interleukin-4. Cross-linking of NTB-A also induces phosphorylation of NTB-A and the association of SAP (SLAM-associated protein), the protein absent in X-linked lymphoproliferative disease. T helper cells differentiated by cross-linking NTB-A and CD3 developed predominantly into Th1 cells not Th2 cells. In vivo blocking of NTB-A interactions with its ligands by using soluble NTB-A-Fc fusion protein inhibits B cell isotype switching to IgG2a and IgG3, commonly induced by Th1-type cytokines. Most important, treatment of mice with NTB-A-Fc delays the onset of antigen-induced experimental allergic encephalomyelitis in myelin basic protein-T cell receptor transgenic mice, suggesting a role in T cell-mediated autoimmune disease. Regulation of interferon-gamma secretion, and not interleukin-4 in vitro, as well as inhibition of Th1 cell-induced isotype switching and attenuation of experimental allergic encephalomyelitis indicate that NTB-A is important for Th1 responses. The observation that cross-linking of NTB-A induces T cell activation, expansion, and Th1-type cytokine production suggests NTB-A is a novel co-stimulatory receptor. The identification of NTB-A as a regulator of T cell response paves the way to provide novel therapeutic approaches for modulation of the immune response.
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PMID:NTB-A, a new activating receptor in T cells that regulates autoimmune disease. 1498 14

Cellular FLIP (c-FLIP) is an endogenous inhibitor of death receptor-induced apoptosis through the caspase 8 pathway. It is an NF-kappaB-inducible protein thought to promote the survival of T cells upon activation, and its down-regulation has been implicated in activation-induced cell death. We have generated transgenic mice overexpressing human c-FLIP long form (c-FLIP(L)) specifically in T cells using the CD2 promoter (TgFLIP(L)). TgFLIP(L) mice exhibit increased IgG1 production upon stimulation by a T cell-dependent Ag and a markedly enhanced contact hypersensitivity response to allergen. In addition to showing augmented Th2-type responses, TgFLIP(L) mice are resistant to the development of myelin oligodendrocyte glycoprotein 35-55 peptide-induced experimental autoimmune encephalomyelitis, a Th1-driven autoimmune disease. In vitro analyses revealed that T cells of TgFLIP(L) mice proliferate normally, but produce higher levels of IL-2 and show preferential maturation of Th2 cytokine-producing cells in response to antigenic stimulation. After adoptive transfer, these (Th2) cells protected wild-type recipient mice from experimental autoimmune encephalomyelitis induction. Our results show that the constitutive overexpression of c-FLIP(L) in T cells is sufficient to drive Th2 polarization of effector T cell responses and indicate that it might function as a key regulator of Th cell differentiation.
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PMID:Cellular FLIP (long isoform) overexpression in T cells drives Th2 effector responses and promotes immunoregulation in experimental autoimmune encephalomyelitis. 1555 52


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