Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Rabbits were immunized with the myelin-associated glycoprotein (MAG) that had been purified from isolated rat brain myelin by selective extraction with lithium diiodosalicylate (LIS) and phenol followed by preparative SDS gel electrophoresis. Antibodies to MAG were detected qualitatively by immunodiffusion and quantitatively by a double antibody assay utilizing [3H]fucose-labeled MAG as antigen. The antisera were capable of precipitating between 300 and 500 micrograms of MAG/ml of serum under the conditions of the assay. Preincubation of the anti-MAG serum with other glycoproteins or glycolipids did not inhibit the precipitation of labeled MAG. Similarly, preincubation of the antiserum with LIS-phenol extracts of non-neural tissues did not inhibit the immune precipitation of MAG. The specificity of the antiserum was also indicated by the selective double antibody precipitation of MAG from solubilized whole myelin that contained a heterogeneous mixture of [3H]fucose-labeled glycoproteins. The antibodies to MAG were not effectively absorbed by whole brain homogenate or purified myelin, indicating that the antigenic site(s) is not accessible in the intact membranes, but can be exposed by treatment with detergent or partial purification. Low levels of antibodies reacting with MAG were detected in three rabbits with experimental allergic encephalomyelitis induced by injection of purified myelin in complete Freund's adjuvant.
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PMID:Preparation and characterization of antisera to the myelin-associated glycoprotein. 617 80

Serum factors in rabbits with white matter-induced experimental allergic encephalomyelitis (WM-EAE) were studied with respect to their role in demyelination in vitro in organotypic central nervous system (CNS) tissue cultures and in vivo in the myelinated retina of the rabbit eye. By absorption with staphylococcal protein A, IgG was quantitatively separated from the other serum proteins. No IgG was demonstrable in the absorbed IgG-depleted sera by Ouchterlony double diffusion, immunoelectrophoresis and SDS-polyacrylamide gel electrophoresis. Both the IgG-depleted WM-EAE sera and the IgG fractions had complement-dependent demyelinating activity on CNS cultures, and both contained immunoglobulin binding to myelin and oligodendroglia of the cultures, as demonstrated by an immunoperoxidase technique. However, only the purified IgG fractions in the absence of complement induced swelling of myelin and proliferation of oligodendroglial processes with redundant myelin in tissue cultures. The IgG-depleted complement-inactivated WM-EAE sera produced no morphological changes. In the rabbit eye model, antibody-dependent cell-mediated demyelination was observed only with the IgG fractions but not with the IgG-depleted EAE sera. No oligodendroglial proliferation occurred. These studies demonstrate for the first time that in CNS cultures, non-IgG immunoglobulins as well as IgG mediate complement-dependent demyelination and that these bind to myelin and oligodendrocytes, whereas only IgG causes myelin swelling and oligodendrocyte proliferation.
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PMID:Experimental allergic encephalomyelitis. Characterization of serum factors causing demyelination and swelling of myelin. 722 59

Haemagglutinating encephalomyelitis virus (HEV), a member of the coronavirus family, was purified and analysed by SDS-polyacrylamide gel electrophoresis. It was shown to contain eight polypeptides, seven of which were glycosylated. They had apparent mol. wt. of 180,000 (GP 180), 130,0000 (GP 130), 120,000 (GP 120) 76,000 (GP 76), 64,000 (VP 64), 54,000 (GP 54), 32,000 (GP 32) and 31,000 (GP 31). Electrophoresis of virus samples dissociated under varying conditions showed that GP 54 and GP 120 could be interpreted as larger products of GP 31 and GP 32 and of GP 76, respectively. GP 76 also appeared as a dimer with a mol. wt. of 140,000 (GP 140) in the absence of beta-mercaptoethanol. Subviral particles, obtained by treatment with bromelain, banded at a slightly lower density than the intact virus and lacked surface projections. Analysis of these particles indicated that GP 180, GP 130 and GP 76 are associated with the virus projections. A small part of GP 31 and GP 32 also appeared to protrude from the lipid envelope since 20% of each molecule was sensitive to digestion. Two glycoproteins, GP 130 and GP 76, were solubilized with the detergent Triton X-100 and separated by rate zonal centrifugation. According to its activity-in indirect haemagglutination tests, GP 76 was considered to be a monovalent haemagglutinin subunit.
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PMID:Characterization and isolation of structural polypeptides in haemagglutinating encephalomyelitis virus. 738 32

Theiler's murine encephalomyelitis virus (TMEV) produces a chronic inflammatory demyelinating disease in its natural host, the mouse. A delayed-type hypersensitivity (DTH) response to viral antigens generally correlates with susceptibility to the disease and is thought to play an important role in the pathogenesis of demyelination in this model of human multiple sclerosis (MS). The hallmark of DTH responses is the recruitment by activated Th-1 cells of lymphoid cells and especially macrophages in infected areas. It is believed that soluble factors released by these cells would produce tissue damage, particularly myelin breakdown. In the present study, we compared TMEV-infected macrophages and microglia, isolated from both susceptible SJL/J and resistant C57BL/6 mice, for their ability to secrete proteolytic enzymes capable of degrading myelin basic protein. In addition, we studied whether supernatants from infected microglia/macrophages were also capable of killing oligodendrocytes in the same in vitro system. As detected by SDS-PAGE, MBP-degrading proteolytic activity was found only in supernatants from infected SJL/J microglia and macrophages, but not in supernatants collected from infected C57BL/6 microglia and macrophages, or in supernatants from mock-infected SJL/J and C57BL/6 cells. Similarly, incubation of E20.1 cells, an immortalized line of oligodendrocytes, with infected SJL/J, but not C57BL/6 supernatants, resulted in cytotoxic activity. When cells from resistant C57BL/6 mice were treated with LPS, they became susceptible to infection and also secreted proteolytic enzymes. The proteolytic activity released from infected microglia and macrophages was found to be dose-dependent, was inactivated by heat, and was inhibited by phenylmethylsulphonyl fluoride (PMSF). These results indicate that a serine protease is released from infected microglia and macrophages and suggest a role for proteases in TMEV-induced myelin injury.
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PMID:Release of myelin basic protein-degrading proteolytic activity from microglia and macrophages after infection with Theiler's murine encephalomyelitis virus: comparison between susceptible and resistant mice. 749 98

Using an inducible expression vector in Escherichia coli, we have expressed, purified, and biologically characterized recombinant human myelin basic protein (r-MBP). The recombinant protein binds in cation-exchange chromatography with similar affinity to purified, human MBP, and elutes as a single, 18.5-kDa species as judged by SDS-PAGE. The recombinant protein exhibits similar conformation to native MBP, as demonstrated by ELISA reactivity with a panel of six monoclonal antibodies directed against at least three different epitopes on human MBP. Additionally, recombinant MBP can trigger the proliferation of human T cell clones recognizing MBP, can induce experimental autoimmune encephalomyelitis (EAE) in the SJL mouse, and is capable of suppressing EAE following tolerization via oral administration. Most important, by using a novel method of purification, the recombinant protein preparation contains no detectable proteolytically derived fragments of MBP, a significant advantage over MBP purified from protease-rich central nervous system tissue. Purified recombinant MBP produced in E. coli will be useful as a biological reagent where highly purified protein devoid of degradation products is needed. Relevance to the study of antigen processing, interactions between MHC and the TCR, as well as for the investigation of antigen-driven immune tolerance are discussed.
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PMID:Biological activity of recombinant human myelin basic protein. 768 37

An effective technique was developed, which allowed rapid isolation of highly pure myelin basic protein (MBP) including its distinct isoforms. The procedure employs homogenization of central nervous system (CNS) tissue in chloroform, which specifically extracts MBP. Subsequently, methanol was used to convert the protein susceptible to quantitative transfer into the acidic aqueous phase. MBP was purified from bovine, chicken, fish, human, guinea-pig, mouse, rabbit, rat, and swine brains. Analysis on SDS-PAGE and immunoblotting using polyclonal MBP-specific serum recognized proteins corresponding to the sizes of previously identified MBP isoforms of 21.5, 18.5, 17.2, and 14.2 kDa and three predicted isoforms of 20.2, 16.0, and 13 kDa. The MBP obtained was readily soluble in water and possessed the capacity to induce experimental autoimmune encephalomyelitis in susceptible mice. The protein was also suitable for use as a substrate for protein kinases.
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PMID:Detection of myelin basic protein isoforms by organic concentration. 929 39

Copolymer 1 (Cop 1) is a random synthetic amino acid copolymer of L-alanine, L-glutamic acid, L-lysine, and L-tyrosine, effective both in suppression of experimental allergic encephalomyelitis and in the treatment of relapsing forms of multiple sclerosis. Cop 1 binds promiscuously and very efficiently to living APCs of various HLA haplotypes. In the present study, a substantial part of the whole mixture of random polypeptides that compose Cop 1 was shown to bind to purified human HLA-DR1, DR2, and DR4 with high affinity in a temperature- and time (and, in the case of DR4, pH)-dependent manner, and was competitively inhibited by DR-restricted peptides, but not by peptide derivatives that bind with low affinity. Bacterial superantigens inhibited Cop 1 binding only at very high concentrations. The formation of the Cop 1-DR1 complex was also shown by SDS-PAGE. These findings represent the first direct evidence for interactions of Cop 1 with purified DR molecules, and suggest that its effectiveness in experimental allergic encephalomyelitis and multiple sclerosis may be directly related to its binding in the groove of HLA-DR proteins.
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PMID:Promiscuous binding of synthetic copolymer 1 to purified HLA-DR molecules. 957 43

Structural and functional studies of murine MHC class II I-A molecules have been limited by the low yield and instability of soluble, recombinant heterodimers. In the murine autoimmune diseases experimental autoimmune encephalomyelitis and collagen-induced arthritis, MHC class II molecules I-Au and I-Aq present peptides derived from myelin basic protein and type II collagen, respectively, to autoreactive T cells. To date, systems for the expression of these two I-A molecules in soluble form for use in structure-function relationship studies have not been reported. In the present study, we have expressed functional I-Au and I-Aq molecules using a baculovirus insect cell system. The chain pairing and stability of the molecules were increased by covalently linking the antigenic peptides to beta-chains and adding carboxyl-terminal leucine zippers. Peptide:I-Aq complex quantitatively formed an SDS-stable dimer, whereas peptide:I-Au formed undetectable amounts. However, the two complexes did not show any significant difference in their response to thermal denaturation as assessed by circular dichroism analyses. The autoantigen peptide:I-A complexes were highly active in stimulating cognate T cells to secrete IL-2 and inducing Ag-specific apoptosis of the T cells. Interestingly, the T cells were stimulated by these soluble molecules in the apparent absence of experimentally induced cross-linking of TCRs, indicating that they may have therapeutic potential in autoimmune disease models.
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PMID:Expression and characterization of recombinant soluble peptide: I-A complexes associated with murine experimental autoimmune diseases. 963 4

Early pregnancy factor (EPF) is a secreted protein with growth regulatory and immunomodulatory properties. It is an extracellular form of the mitochondrial matrix protein chaperonin 10 (Cpn10), a molecular chaperone. An understanding of the mechanism of action of EPF and an exploration of therapeutic potential has been limited by availability of purified material. The present study was undertaken to develop a simple high-yielding procedure for preparation of material for structure/function studies, which could be scaled up for therapeutic application. Human EPF was expressed in Sf9 insect cells by baculovirus infection and in Escherichia coli using a heat inducible vector. A modified molecule with an additional N-terminal alanine was also expressed in E. coli. The soluble protein was purified from cell lysates via anion exchange (negative-binding mode), cation exchange, and hydrophobic interaction chromatography, yielding approximately 42 and 36mg EPF from 300ml bacterial and 1L Sf9 cultures, respectively. The preparations were highly purified (#10878;99% purity on SDS-PAGE for the bacterial products and #10878;97% for that of insect cells) and had the expected mass and heptameric structure under native conditions, as determined by mass spectrometry and gel permeation chromatography, respectively. All recombinant preparations exhibited activity in the EPF bioassay, the rosette inhibition test, with similar potency both to each other and to the native molecule. In two in vivo assays of immunosuppressive activity, the delayed-type hypersensitivity reaction and experimental autoimmune encephalomyelitis, the insect cell and modified bacterial products, both with N-terminal additions (acetylation or amino acid), exhibited similar levels of suppressive activity, but the bacterial product with no N-terminal modification had no effect in either assay. Studies by others have shown that N-terminal addition is not necessary for Cpn10 activity. By defining techniques for facile production of molecules with and without immunosuppressive properties, the present studies make it possible to explore mechanisms underlying the distinction between EPF and Cpn10 activity.
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PMID:Purification and characterisation of functional early pregnancy factor expressed in Sf9 insect cells and in Escherichia coli. 1496 74

We have induced a polyclonal IgG that degrades the HIV-1 surface antigen, glycoprotein gp120, by taking advantage of the susceptibility of SJL mice to a peptide-induced autoimmune disorder, experimental autoimmune encephalomyelitis (EAE). Specific pathogen-free SJL mice were immunized with structural fragments of gp120, fused in-frame with encephalitogenic peptide MBP(85-101). It has resulted in a pronounced disease-associated immune response against antigens. A dramatic increase of gp120 degradation level by purified polyclonal IgG from immunized versus nonimmunized mice has been demonstrated by a newly developed fluorescence-based assay. This activity was inhibited by anti-mouse immunoglobulin antibodies as well as by Ser- and His-reactive covalent inhibitors. A dominant proteolysis site in recombinant gp120 incubated with purified polyclonal IgG from immunized mice was shown by SDS-PAGE. The SELDI-based mass spectrometry revealed that these antibodies exhibited significant specificity toward the Pro484-Leu485 peptide bond. The sequence surrounding this site is present in nearly half of the HIV-I variants. This novel strategy can be generalized for creating a catalytic vaccine against viral pathogens.
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PMID:Induction of a protein-targeted catalytic response in autoimmune prone mice: antibody-mediated cleavage of HIV-1 glycoprotein GP120. 1638 9


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