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Vijay K Kuchroo - One of the best experts on this subject based on the ideXlab platform.
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Prfnted In U.S.A. IDENTIFICATION AND CHARACTERIZATION OF A SECOND ENCEPHALITOGENIC DETERMINANT OF Myelin Proteolipid Protein (RESIDUES 178-191) FOR SJL MICE'
2015Co-Authors: Judith M. Greer, Vijay K Kuchroo, Raymond A. Sobel, Marjorie B. LeesctAbstract:We previously described a synthetic peptide of Myelin Proteolipid Protein (PLP), peptide 139-151, which induces experimental allergic encephalomye-litis in SJL/J (H-2") mice. We have now identified an additional determinant, PLP residues 178-1 91, that is also a potent encephalitogen in this strain. When PLP peptide 178-191 was compared with peptide 139- 15 1 on an equimolar basis, the day of onset of disease induced by PLP 178-191 was earlier, but the incidence, severity, and histologic features were indistinguishable. Lymph node cells from animals immunized with the whole PLP molecule responded to both PLP 178-191 and 139-151, suggesting im-munologic codominance of the two epitopes. PLP 178-1 91 elicited stronger proliferative response
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Myelin Proteolipid Protein specific cd4 cd25 regulatory cells mediate genetic resistance to experimental autoimmune encephalomyelitis
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: N Jayagopala R Reddy, Lindsay B Nicholson, Raymond A. Sobel, Zsolt Illes, Xingmin Zhang, Jeffrey Encinas, Jason Pyrdol, Kai W Wucherpfennig, Vijay K KuchrooAbstract:SJL mice are highly susceptible to experimental autoimmune encephalomyelitis (EAE) induced with Myelin Proteolipid Protein (PLP) peptide 139-151, whereas H-2 congenic B10.S mice are resistant. Immunodominance and susceptibility to EAE are associated with a high precursor frequency of PLP 139-151-specific T cells in the naive repertoire of SJL mice. To understand the mechanism of EAE resistance in B10.S mice, we determined the precursor frequency of PLP 139-151-reactive T cells in both strains by using IAs/PLP 139-151 tetramers. SJL and B10.S mice had similar frequencies of tetramer-reactive T cells in the naive peripheral repertoire. However, in SJL mice, the majority of PLP 139-151 tetramer-positive cells were in the CD4+CD25- population, whereas there were more tetramer-positive cells in the CD4+CD25+ population of B10.S mice. Depletion of CD4+CD25+ cells in vivo facilitated the expansion of PLP 139-151-reactive cells with production of T helper 1 cytokines in EAE-resistant B10.S mice. Furthermore, anti-CD25 Ab treatment before immunization resulted in EAE induction in these otherwise resistant mice. These data indicate an important role for autoantigen-specific CD4+CD25+ cells in genetic resistance to autoimmunity.
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detection of autoreactive Myelin Proteolipid Protein 139 151 specific t cells by using mhc ii ias tetramers
Journal of Immunology, 2003Co-Authors: N Jayagopala R Reddy, Lindsay B Nicholson, Kai W Wucherpfennig, Estelle Bettelli, Hanspeter Waldner, Mei Huei Jang, Vijay K KuchrooAbstract:Detection of autoreactive T cells using MHC II tetramers is difficult because of the low affinity of their TCR. We have generated a class II tetramer using the IA s class II molecule combined with an autoantigenic peptide from Myelin Proteolipid Protein (PLP; PLP 139–151 ) and used it to analyze Myelin PLP 139–151 -reactive T cells. Using monomers and multimerized complexes labeled with PE, we confirmed the specificity of the reagent by bioassay and flow cytometry. The IA s tetramers stimulated and stained the PLP 139–151 -specific 5B6 TCR transgenic T cells and a polyclonal cell line specific for PLP 139–151 , but not a control T cell line specific for PLP 178–191 . We used this reagent to optimize conditions to detect low affinity autoreactive T cells. We found that high pH (∼8.0) and neuraminidase treatment enhances the staining capacity of PLP 139–151 tetramer without compromising specificity. Furthermore, we found that induction of calcium fluxing by tetramers in T cells may be used as a sensitive measure to detect autoreactive T cells with a low affinity. Taken together, the data show that the tetrameric reagent binds and stimulates PLP 139–151 -reactive T cells with specificity. This tetrameric reagent will be useful in studying the evolution of PLP 139–151 -specific repertoire in naive mice and its expansion during the autoimmune disease experimental autoimmune encephalomyelitis.
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detection of autoreactive Myelin Proteolipid Protein 139 151 specific t cells by using mhc ii ias tetramers
Journal of Immunology, 2003Co-Authors: N Jayagopala R Reddy, Lindsay B Nicholson, Kai W Wucherpfennig, Estelle Bettelli, Hanspeter Waldner, Mei Huei Jang, Vijay K KuchrooAbstract:Detection of autoreactive T cells using MHC II tetramers is difficult because of the low affinity of their TCR. We have generated a class II tetramer using the IA(s) class II molecule combined with an autoantigenic peptide from Myelin Proteolipid Protein (PLP; PLP(139-151)) and used it to analyze Myelin PLP(139-151)-reactive T cells. Using monomers and multimerized complexes labeled with PE, we confirmed the specificity of the reagent by bioassay and flow cytometry. The IA(s) tetramers stimulated and stained the PLP(139-151)-specific 5B6 TCR transgenic T cells and a polyclonal cell line specific for PLP(139-151), but not a control T cell line specific for PLP(178-191). We used this reagent to optimize conditions to detect low affinity autoreactive T cells. We found that high pH ( approximately 8.0) and neuraminidase treatment enhances the staining capacity of PLP(139-151) tetramer without compromising specificity. Furthermore, we found that induction of calcium fluxing by tetramers in T cells may be used as a sensitive measure to detect autoreactive T cells with a low affinity. Taken together, the data show that the tetrameric reagent binds and stimulates PLP(139-151)-reactive T cells with specificity. This tetrameric reagent will be useful in studying the evolution of PLP(139-151)-specific repertoire in naive mice and its expansion during the autoimmune disease experimental autoimmune encephalomyelitis.
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high frequency of autoreactive Myelin Proteolipid Protein specific t cells in the periphery of naive mice mechanisms of selection of the self reactive repertoire
Journal of Experimental Medicine, 2000Co-Authors: Ana C Anderson, Lindsay B Nicholson, Kevin L Legge, Vadim Turchin, Habib Zaghouani, Vijay K KuchrooAbstract:The autoreactive T cells that escape central tolerance and form the peripheral self-reactive repertoire determine both susceptibility to autoimmune disease and the epitope dominance of a specific autoantigen. SJL (H-2s) mice are highly susceptible to the induction of experimental autoimmune encephalomyelitis (EAE) with Myelin Proteolipid Protein (PLP). The two major encephalitogenic epitopes of PLP (PLP 139–151 and PLP 178–191) bind to IAs with similar affinity; however, the immune response to the PLP 139–151 epitope is always dominant. The immunodominance of the PLP 139–151 epitope in SJL mice appears to be due to the presence of expanded numbers of T cells (frequency of 1/20,000 CD4+ cells) reactive to PLP 139–151 in the peripheral repertoire of naive mice. Neither the PLP autoantigen nor infectious environmental agents appear to be responsible for this expanded repertoire, as endogenous PLP 139–151 reactivity is found in both PLP-deficient and germ-free mice. The high frequency of PLP 139–151-reactive T cells in SJL mice is partly due to lack of thymic deletion to PLP 139–151, as the DM20 isoform of PLP (which lacks residues 116–150) is more abundantly expressed in the thymus than full-length PLP. Reexpression of PLP 139–151 in the embryonic thymus results in a significant reduction of PLP 139–151-reactive precursors in naive mice. Thus, escape from central tolerance, combined with peripheral expansion by cross-reactive antigen(s), appears to be responsible for the high frequency of PLP 139–151-reactive T cells.
Marjorie B. Lees - One of the best experts on this subject based on the ideXlab platform.
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acylation of rat brain Myelin Proteolipid Protein with different fatty acids
Journal of Neurochemistry, 2006Co-Authors: Oscar A. Bizzozero, James F Mcgarry, Marjorie B. LeesAbstract:The acylation of rat brain Proteolipid Protein (PLP) with tritiated palmitic, oleic, and myristic acids was studied in vivo and in vitro and compared with the acylation of lipids. Twenty-four hours after intracranial injection of [3H]myristic acid, only 16% of the PLP-bound label appeared as myristic acid, with 66% as palmitic, 9% as stearic, and 6% as oleic acid, whereas greater than 63% of the label in total or Myelin phospholipid was in the form of myristic acid. In contrast, after labelling with [3H]palmitic or oleic acids, 75% and 86%, respectively, of the radioactivity in PLP remained in the original form. When brain tissue slices were incubated for short periods of time, the incorporation of palmitic and oleic acids into PLP exceeded that of myristic acid by a factor of 8. In both systems and with all precursors studied, the label associated with PLP was shown to be in ester linkage. The results suggest a preferential acylation of PLP with palmitic and oleic acids as compared with myristic acid. This is consistent with the fatty acid composition of the isolated PLP.
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Myelin Proteolipid Protein the first 50 years
The International Journal of Biochemistry & Cell Biology, 2002Co-Authors: Judith M. Greer, Marjorie B. LeesAbstract:Myelin Proteolipid Protein (PLP), the most abundant Protein of central nervous system (CNS) Myelin, is a hydrophobic integral membrane Protein. Because of its physical properties, which make it difficult to work with, progress towards determining the exact function(s) and disease associations of Myelin PLP has been slow. However, recent molecular biology advances have given new life to investigations of PLP, and suggest that it has multiple functions within Myelin and is of importance in several neurological disorders.
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Fatty Acid Composition of Myelin Proteolipid Protein During Vertebrate Evolution
Neurochemical Research, 1999Co-Authors: Oscar A. Bizzozero, Marjorie B. LeesAbstract:The hydrophobic Myelin Proteolipid Protein (PLP) contains covalently bound long-chain fatty acids which are attached to intracellular cysteine residues via thioester linkages. To gain insight into the role of acylation in the structure and function of Myelin PLP, the amount and pattern of acyl groups attached to the Protein during vertebrate evolution was determined. PLP isolated from brain Myelin of amphibians, reptiles, birds and several mammals was subjected to alkaline methanolysis and the released methyl esters were analyzed by gas-liquid chromatography. In all species studied, PLP contained approximately the same amount of covalently bound fatty acids (3% w/w), and palmitic, palmitoleic, oleic and stearic acids were always the major acyl groups. Although the relative proportions of these fatty acids changed during evolution, the changes did not necessarily follow the variations in the acyl chain composition of the Myelin free fatty acid pool, suggesting fatty acid specificity. The phylogenetic conservation of acylation suggests that this post-translational modification is critical for PLP function.
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immunogenic and encephalitogenic epitope clusters of Myelin Proteolipid Protein
Journal of Immunology, 1996Co-Authors: Judith M. Greer, Raymond A. Sobel, Marjorie B. Lees, Scott Southwood, A Sette, Vijay K KuchrooAbstract:To understand and develop strategies to intervene in autoimmune responses to Myelin Proteolipid Protein (PLP), encephalitogenic epitopes must be identified. To expedite the identification of potentially immunogenic and encephalitogenic epitopes of PLP, overlapping synthetic 20-mer PLP peptides covering the whole PLP molecule were screened for their ability to bind to purified mouse I-Ad, I-Ak, and I-As molecules. The peptides that bound to the I-A molecules were tested for their ability to induce immune responses in corresponding inbred mouse strains. Immunogenic peptides were then tested for their ability to induce experimental autoimmune encephalomyelitis. Moderate to strong I-A binding was essential for development of immune responses, but immunogenicity was not sufficient for encephalitogenicity. Rather, encephalitogenic epitopes clustered in three regions of the molecule, namely within residues 40-70, 100-119, and 178-209. These were also the regions of the PLP that showed the greatest promiscuity in binding to I-A molecules. Except for PLP 139-151, which is an encephalitogenic determinant in mice expressing I-As, all encephalitogenic epitopes of PLP previously identified, regardless of their MHC class II restriction, are located within or adjacent to these epitope clusters. None of the encephalitogenic epitopes occur in regions of the molecule that have a high degree of homology with the neuronal M6a Protein, a member of the DM20/PLP superfamily. Atypical clinical and histologic patterns of experimental autoimmune encephalomyelitis were observed in some strains of mice sensitized with certain PLP peptides and may reflect induction of T cells with different disease-inducing potentials.
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expression of Myelin Proteolipid Protein in oligodendrocytes and transfected cells
Progress in Brain Research, 1995Co-Authors: Marjorie B. Lees, Judith M. Greer, Frances I Smith, Charissa A Dyer, Magdolna PakaskiAbstract:Publisher Summary This chapter discusses the expression of Myelin Proteolipid Protein (PLP) in oligodendrocytes and transfected cells. An approach to reveal functional properties of PLP is to express PLP and its isoforms in cells other than oligodendrocytes. Transfection of PLP and DM20, individually or together, should allow the assessment of the normal behavior of these Proteins, whereas site directed mutagenesis would show the consequences of point mutations or deletions. The key questions to be addressed initially are whether PLP and DM20 are individually targeted to the plasma membrane and, assuming they get to the membrane, whether they are incorporated in a correct orientation. In immunofluorescence study, the examination of fixed and permeabilized COS-1 (African green monkey kidney cells) cells that had been transfected with either PLP or DM20 cDNA showed extensive vesicular staining with AB3, an antibody that reacts with the C terminal region of both PLP and DM20. The vesicular staining pattern was observed mainly in the perinuclear region, but also in the processes of the transfected cells. In some cases, the processes appeared to be in contact with adjacent cells. Intense immunostaining was also evident along the portions of the perimeter of the cells, suggesting that the PLP had indeed been targeted to the cell surface.
Judith M. Greer - One of the best experts on this subject based on the ideXlab platform.
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correlation between anti Myelin Proteolipid Protein plp antibodies and disease severity in multiple sclerosis patients with plp response permissive hla types
Frontiers in Immunology, 2020Co-Authors: Judith M. Greer, Elisabeth Trifilieff, Michael P PenderAbstract:The most prominent pathological features of multiple sclerosis (MS) are deMyelination and neurodegeneration. The exact pathogenesis of MS is unknown, but it is generally regarded as a T cell-mediated autoimmune disease. Increasing evidence, however, suggests that other components of the immune system, particularly B cells and antibodies, contribute to the cumulative CNS damage and worsening disability that characterize the disease course in many patients. We have previously described strongly elevated T cell reactivity to an extracellular domain of the most abundant CNS Myelin Protein, Myelin Proteolipid Protein (PLP) in people with MS. The current paper addresses the question of whether this region of PLP is also a target of autoantibodies in MS. Here we show that serum levels of isotype-switched anti-PLP181-230 specific antibodies are significantly elevated in patients with MS compared to healthy individuals and patients with other neurological diseases. These anti-PLP181-230 antibodies can also live-label PLP-transfected cells, confirming that they can recognize native PLP expressed at the cell surface. Importantly, the antibodies are only elevated in patients who carry HLA molecules that allow strong T cell responses to PLP. In that subgroup of patients, there is a positive correlation between the levels of anti-PLP181-230 antibodies and the severity of MS. These results demonstrate that anti-PLP antibodies have potentially important roles to play in the pathogenesis of MS.
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antibodies specific for Myelin Proteolipid Protein can inhibit reMyelination in vivo s52 001
Neurology, 2018Co-Authors: Bridget Bagert, Judith M. Greer, Hannah Savage, Shannon J Beasley, Gracy Juba, Michael P PenderAbstract:Objective: The aim of the current study was to investigate whether the anti-Proteolipid Protein (PLP) antibodies present in sera from multiple sclerosis (MS) patients had any effects on reMyelination in vivo. Background: MS is a chronic inflammatory deMyelinating disease of the central nervous system (CNS). Autoimmune T cells are critical for the pathogenesis of MS, but pathogenic roles for autoantibodies in MS are less clear. We have found that about 40% of MS patients have elevated levels (compared to healthy controls and patients with other neurological diseases) of autoantibodies specific for the second extracellular loop of Myelin PLP, the most abundant CNS Myelin Protein. Recently, it has been found that PLP interacts with integrins on the surface of oligodendrocyte precursor cells (OPCs) to allow migration of the OPCs. Migration of OPCs to sites of CNS deMyelination is critical for subsequent reMyelination of nerve fibers and resolution of attacks of disease in MS. Design/Methods: DeMyelination of the corpus callosum was induced by feeding cuprizone to mice for six weeks. Once feeding ceases, spontaneous reMyelination of the corpus callosum normally occurs within three weeks. Purified IgG from controls, IgG from MS patients with high levels of anti-PLP antibody, or MS patient IgG from which all PLP-specific antibodies had been removed, was injected into mice from the fifth week of cuprizone feeding for three weeks. Brains of mice were assessed by diffusion tensor imaging (DTI) at weeks 0, 5 and 9, and by histological assessment (following the last scan). Results: Mice receiving IgG containing anti-PLP antibody, but not mice treated with the other IgG fractions, showed significantly reduced levels of reMyelination in the corpus callosum. Conclusions: These findings show that anti-PLP antibodies could potentially inhibit reMyelination in MS, and suggest that specifically depleting anti-PLP antibodies (e.g. by immunoabsorption apheresis) might be clinically indicated in patients with these autoantibodies. Disclosure: Dr. Bagert has nothing to disclose. Dr. Greer has nothing to disclose. Dr. Savage has nothing to disclose. Dr. Beasley has nothing to disclose. Dr. Juba has nothing to disclose. Dr. Pender has nothing to disclose.
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Prfnted In U.S.A. IDENTIFICATION AND CHARACTERIZATION OF A SECOND ENCEPHALITOGENIC DETERMINANT OF Myelin Proteolipid Protein (RESIDUES 178-191) FOR SJL MICE'
2015Co-Authors: Judith M. Greer, Vijay K Kuchroo, Raymond A. Sobel, Marjorie B. LeesctAbstract:We previously described a synthetic peptide of Myelin Proteolipid Protein (PLP), peptide 139-151, which induces experimental allergic encephalomye-litis in SJL/J (H-2") mice. We have now identified an additional determinant, PLP residues 178-1 91, that is also a potent encephalitogen in this strain. When PLP peptide 178-191 was compared with peptide 139- 15 1 on an equimolar basis, the day of onset of disease induced by PLP 178-191 was earlier, but the incidence, severity, and histologic features were indistinguishable. Lymph node cells from animals immunized with the whole PLP molecule responded to both PLP 178-191 and 139-151, suggesting im-munologic codominance of the two epitopes. PLP 178-1 91 elicited stronger proliferative response
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Myelin Proteolipid Protein an effective autoantigen and target of autoimmunity in multiple sclerosis
Journal of Autoimmunity, 2008Co-Authors: Judith M. Greer, Michael P PenderAbstract:Myelin Proteolipid Protein (PLP) is the most abundant Protein in central nervous system (CNS) Myelin and plays a major role in maintaining the structural and functional integrity of Myelin. Its abundance in, and restriction to, CNS Myelin and its post-translational modification by acylation make PLP an effective autoantigen, which can induce experimental autoimmune encephalomyelitis in rodents and non-human primates and which is a target of pathogenic autoimmunity in people with multiple sclerosis, a chronic inflammatory deMyelinating CNS disease.
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blood brain barrier disruption and lesion localisation in experimental autoimmune encephalomyelitis with predominant cerebellar and brainstem involvement
Journal of Neuroimmunology, 2005Co-Authors: Diane M Muller, Michael P Pender, Judith M. GreerAbstract:The role of the blood-brain barrier (BBB) in determining lesion distribution was assessed in an atypical model of experimental autoimmune encephalomyelitis (EAE) induced in C3H/HeJ mice by immunisation with peptide 190-209 of Myelin Proteolipid Protein, which can result in two distinct types of EAE, each with distinct lesion distribution. Areas of the BBB showing constitutively greater permeability in naive mice did not correlate with the lesion distribution in EAE. BBB disruption occurred only in sites of inflammatory cell infiltration. Irrespective of the clinical type, the BBB was disrupted in the cerebellum and brainstem. Pertussis toxin had no effect on lesion distribution. Thus, lesion distribution is not influenced solely by BBB permeability.
Raymond A. Sobel - One of the best experts on this subject based on the ideXlab platform.
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anti Myelin Proteolipid Protein peptide monoclonal antibodies recognize cell surface Proteins on developing neurons and inhibit their differentiation
Journal of Neuropathology and Experimental Neurology, 2019Co-Authors: Raymond A. Sobel, Mary Jane Eaton, Prajakta D Jaju, Eugene Lowry, Julian R HinojozaAbstract:Using a panel of monoclonal antibodies (mAbs) to Myelin Proteolipid Protein (PLP) peptides, we found that in addition to CNS Myelin, mAbs to external face but not cytoplasmic face epitopes immunostained neurons in immature human CNS tissues and in adult hippocampal dentate gyrus and olfactory bulbs, that is neural stem cell niches (NSCN). To explore the pathobiological significance of these observations, we assessed the mAb effects on neurodifferentiation in vitro. The mAbs to PLP 50-69 (IgG1κ and IgG2aκ), and 178-191 and 200-219 (both IgG1κ) immunostained live cell surfaces and inhibited neurite outgrowth of E18 rat hippocampal precursor cells and of PC12 cells, which do not express PLP. Proteins immunoprecipitated from PC12 cell extracts and captured by mAb-coated magnetic beads were identified by GeLC-MS/MS. Each neurite outgrowth-inhibiting mAb captured a distinct set of neurodifferentiation molecules including sequence-similar M6 Proteins and other unrelated membrane and extracellular matrix Proteins, for example integrins, Eph receptors, NCAM-1, and protocadherins. These molecules are expressed in adult human NSCN and are implicated in the pathogenesis of many chronic CNS disease processes. Thus, diverse anti-PLP epitope autoantibodies may inhibit neuronal precursor cell differentiation via multispecific recognition of cell surface molecules thereby potentially impeding endogenous neuroregeneration in NSCN and in vivo differentiation of exogenous neural stem cells.
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Prfnted In U.S.A. IDENTIFICATION AND CHARACTERIZATION OF A SECOND ENCEPHALITOGENIC DETERMINANT OF Myelin Proteolipid Protein (RESIDUES 178-191) FOR SJL MICE'
2015Co-Authors: Judith M. Greer, Vijay K Kuchroo, Raymond A. Sobel, Marjorie B. LeesctAbstract:We previously described a synthetic peptide of Myelin Proteolipid Protein (PLP), peptide 139-151, which induces experimental allergic encephalomye-litis in SJL/J (H-2") mice. We have now identified an additional determinant, PLP residues 178-1 91, that is also a potent encephalitogen in this strain. When PLP peptide 178-191 was compared with peptide 139- 15 1 on an equimolar basis, the day of onset of disease induced by PLP 178-191 was earlier, but the incidence, severity, and histologic features were indistinguishable. Lymph node cells from animals immunized with the whole PLP molecule responded to both PLP 178-191 and 139-151, suggesting im-munologic codominance of the two epitopes. PLP 178-1 91 elicited stronger proliferative response
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Myelin Proteolipid Protein specific cd4 cd25 regulatory cells mediate genetic resistance to experimental autoimmune encephalomyelitis
Proceedings of the National Academy of Sciences of the United States of America, 2004Co-Authors: N Jayagopala R Reddy, Lindsay B Nicholson, Raymond A. Sobel, Zsolt Illes, Xingmin Zhang, Jeffrey Encinas, Jason Pyrdol, Kai W Wucherpfennig, Vijay K KuchrooAbstract:SJL mice are highly susceptible to experimental autoimmune encephalomyelitis (EAE) induced with Myelin Proteolipid Protein (PLP) peptide 139-151, whereas H-2 congenic B10.S mice are resistant. Immunodominance and susceptibility to EAE are associated with a high precursor frequency of PLP 139-151-specific T cells in the naive repertoire of SJL mice. To understand the mechanism of EAE resistance in B10.S mice, we determined the precursor frequency of PLP 139-151-reactive T cells in both strains by using IAs/PLP 139-151 tetramers. SJL and B10.S mice had similar frequencies of tetramer-reactive T cells in the naive peripheral repertoire. However, in SJL mice, the majority of PLP 139-151 tetramer-positive cells were in the CD4+CD25- population, whereas there were more tetramer-positive cells in the CD4+CD25+ population of B10.S mice. Depletion of CD4+CD25+ cells in vivo facilitated the expansion of PLP 139-151-reactive cells with production of T helper 1 cytokines in EAE-resistant B10.S mice. Furthermore, anti-CD25 Ab treatment before immunization resulted in EAE induction in these otherwise resistant mice. These data indicate an important role for autoantigen-specific CD4+CD25+ cells in genetic resistance to autoimmunity.
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Thiopalmitoylation of Myelin Proteolipid Protein epitopes enhances immunogenicity and encephalitogenicity.
Journal of immunology (Baltimore Md. : 1950), 2001Co-Authors: Judith M. Greer, Raymond A. Sobel, Bérangère Denis, Elisabeth TrifilieffAbstract:Proteolipid Protein (PLP) is the most abundant Protein of CNS Myelin, and is posttranslationally acylated by covalent attachment of long chain fatty acids to cysteine residues via a thioester linkage. Two of the acylation sites are within epitopes of PLP that are encephalitogenic in SJL/J mice (PLP 104–117 and PLP 139–151 ) and against which increased immune responses have been detected in some multiple sclerosis patients. It is known that attachment of certain types of lipid side chains to peptides can result in their enhanced immunogenicity. The aim of this study was to determine whether thioacylated PLP peptides, as occur in the native Protein, are more immunogenic than their nonacylated counterparts, and whether thioacylation influences the development of autoreactivity and experimental autoimmune encephalomyelitis. The results show that in comparison with nonacylated peptides, thioacylated PLP lipopeptides can induce greater T cell and Ab responses to both the acylated and nonacylated peptides. They also enhanced the development and chronicity of experimental autoimmune encephalomyelitis. Synthetic peptides in which the fatty acid was attached via an amide linkage at the N terminus were not encephalitogenic, and they induced greater proportions of CD8 + cells in initial in vitro stimulation. Therefore, the lability and the site of the linkage between the peptide and fatty acid may be important for induction of encephalitogenic CD4 + T cells. These results suggest that immune responses induced by endogenous thioacylated lipopeptides may contribute to the immunopathogenesis of chronic experimental deMyelinating diseases and multiple sclerosis.
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immunogenic and encephalitogenic epitope clusters of Myelin Proteolipid Protein
Journal of Immunology, 1996Co-Authors: Judith M. Greer, Raymond A. Sobel, Marjorie B. Lees, Scott Southwood, A Sette, Vijay K KuchrooAbstract:To understand and develop strategies to intervene in autoimmune responses to Myelin Proteolipid Protein (PLP), encephalitogenic epitopes must be identified. To expedite the identification of potentially immunogenic and encephalitogenic epitopes of PLP, overlapping synthetic 20-mer PLP peptides covering the whole PLP molecule were screened for their ability to bind to purified mouse I-Ad, I-Ak, and I-As molecules. The peptides that bound to the I-A molecules were tested for their ability to induce immune responses in corresponding inbred mouse strains. Immunogenic peptides were then tested for their ability to induce experimental autoimmune encephalomyelitis. Moderate to strong I-A binding was essential for development of immune responses, but immunogenicity was not sufficient for encephalitogenicity. Rather, encephalitogenic epitopes clustered in three regions of the molecule, namely within residues 40-70, 100-119, and 178-209. These were also the regions of the PLP that showed the greatest promiscuity in binding to I-A molecules. Except for PLP 139-151, which is an encephalitogenic determinant in mice expressing I-As, all encephalitogenic epitopes of PLP previously identified, regardless of their MHC class II restriction, are located within or adjacent to these epitope clusters. None of the encephalitogenic epitopes occur in regions of the molecule that have a high degree of homology with the neuronal M6a Protein, a member of the DM20/PLP superfamily. Atypical clinical and histologic patterns of experimental autoimmune encephalomyelitis were observed in some strains of mice sensitized with certain PLP peptides and may reflect induction of T cells with different disease-inducing potentials.
Patricia A Wight - One of the best experts on this subject based on the ideXlab platform.
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Effects of Intron 1 Sequences on Human Expression: Implications for -Related Disorders
'SAGE Publications', 2017Co-Authors: Patricia A WightAbstract:Alterations in the Myelin Proteolipid Protein gene ( PLP1 ) may result in rare X-linked disorders in humans such as Pelizaeus–Merzbacher disease and spastic paraplegia type 2. PLP1 expression must be tightly regulated since null mutations, as well as elevated PLP1 copy number, both lead to disease. Previous studies with Plp1-lacZ transgenic mice have demonstrated that mouse Plp1 ( mPlp1 ) intron 1 DNA (which accounts for slightly more than half of the gene) is required for the mPlp1 promoter to drive significant levels of reporter gene expression in brain. However not much is known about the mechanisms that control expression of the human PLP1 gene ( hPLP1 ). Therefore this review will focus on sequences in hPLP1 intron 1 DNA deemed important for hPLP1 gene activity as well as a couple of “human-specific” supplementary exons within the first intron which are utilized to generate novel splice variants, and the potential role that these sequences may play in PLP1 -linked disorders
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targeted deletion of the antisilencer enhancer ase element from intron 1 of the Myelin Proteolipid Protein gene plp1 in mouse reveals that the element is dispensable for plp1 expression in brain during development and reMyelination
Journal of Neurochemistry, 2013Co-Authors: Glauber B Pereira, Fanxue Meng, Neriman T Kockara, Baoli Yang, Patricia A WightAbstract:Myelin Proteolipid Protein gene (Plp1) expression is temporally regulated in brain, which peaks during the active Myelination period of CNS development. Previous studies with Plp1-lacZ transgenic mice demonstrated that (mouse) Plp1 intron 1 DNA is required for high levels of expression in oligodendrocytes. Deletion-transfection analysis revealed the intron contains a single positive regulatory element operative in the N20.1 oligodendroglial cell line, which was named ASE (antisilencer/enhancer) based on its functional properties in these cells. To investigate the role of the ASE in vivo, the element was deleted from the native gene in mouse using a Cre/lox strategy. Although removal of the ASE from Plp1-lacZ constructs profoundly decreased expression in transfected oligodendroglial cell lines (N20.1 and Oli-neu), the element was dispensable to achieve normal levels of Plp1 gene expression in mouse during development (except perhaps at postnatal day 15) and throughout the reMyelination period following cuprizone-induced (acute) deMyelination. Thus, it is possible that the ASE is non-functional in vivo, or that loss of the ASE from the native gene in mouse can be compensated for by the presence of other regulatory elements within the Plp1 gene.
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expression of a Myelin Proteolipid Protein plp lacz transgene is reduced in both the cns and pns of plp jp mice
Neurochemical Research, 2007Co-Authors: Patricia A Wight, Tatyana I Gudz, Cynthia S Duchala, Elizabeth H Shick, Wendy B MacklinAbstract:Jimpy (Plpjp) is an X-linked recessive mutation in mice that causes CNS dysMyelination and early death in affected males. It results from a point mutation in the acceptor splice site of Myelin Proteolipid Protein (Plp) exon 5, producing transcripts that are missing exon 5, with a concomitant shift in the downstream reading frame. Expression of the mutant PLP product in Plpjp males leads to hypoMyelination and oligodendrocyte death. Expression of our Plp-lacZ fusion gene, PLP(+)Z, in transgenic mice is an excellent readout for endogenous Plp transcriptional activity. The current studies assess expression of the PLP(+)Z transgene in the Plpjp background. These studies demonstrate that expression of the transgene is decreased in both the central and peripheral nervous systems of affected Plpjp males. Thus, expression of mutated PLP Protein downregulates Plp gene activity both in oligodendrocytes, which eventually die, and in Schwann cells, which are apparently unaffected in Plpjp mice.
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characterization of an intronic enhancer that regulates Myelin Proteolipid Protein plp gene expression in oligodendrocytes
Journal of Neuroscience Research, 2005Co-Authors: Fanxue Meng, Natalia A Kokorina, Anna Dobretsova, Olga Zolova, Patricia A WightAbstract:The Myelin Proteolipid Protein (Plp) gene is expressed in oligodendrocytes and encodes the most abundant Protein (∼50%) present in mature Myelin from the central nervous system (CNS). Plp gene activity is low to nonexistent early in development but sharply increases, concurrently with the active Myelination period of CNS development. Work from our laboratory suggests that the temporal regulation of Plp gene expression in mice is mediated by a positive regulatory element located within Plp intron 1 DNA. We have termed this regulatory element/region ASE (for antisilencer/enhancer). The ASE is situated approximately 1 kb downstream of exon 1 DNA and encompasses nearly 100 bp. To understand the mechanisms by which the ASE augments Plp gene expression in oligodendrocytes, Plp-lacZ constructs were generated and transfected into a mouse oligodendroglial cell line (N20.1). Results presented here demonstrate that upstream regulatory elements in the Plp promoter/5′-flanking DNA are not required for ASE activity; the ASE worked perfectly well when the thymidine kinase (TK) promoter was substituted for the Plp promoter. However, the relative location of the ASE appears to be important. When placed upstream of 2.4 kb of Plp 5′-flanking DNA, or downstream of the lacZ expression cassette, the ASE was no longer effective. Thus, the ASE might have to be in the context of the intron in order to function. To begin to identify the crucial nucleotides within the ASE, orthologous sequences from rat, human, cow, and pig Plp genes were swapped for the mouse sequence. Results presented here demonstrate that the orthologous sequence from rat can substitute for the mouse ASE, unlike those from human, cow, or pig. © 2005 Wiley-Liss, Inc.
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potentiation of Myelin Proteolipid Protein plp gene expression is mediated through ap 1 like binding sites
Journal of Neurochemistry, 2004Co-Authors: Anna Dobretsova, Natalia A Kokorina, Patricia A WightAbstract:The Myelin Proteolipid Protein (Plp) gene is expressed in oligodendrocytes and encodes the most abundant Protein found in mature CNS Myelin. Expression of the gene is dynamic and peaks during the active Myelination period of CNS development. The surge in Plp gene activity during this period has been purported to be mediated by a positive regulatory region located within the first intron. This region, designated ASE for antisilencer/enhancer, is located approximately 1 kb downstream of exon 1 sequences and encompasses nearly 100 bp. However, neither the critical nucleotides within this region, nor the associated DNA-binding Proteins have been identified. In the present study, DNase I footprinting analysis demonstrated widespread protection of the region on both the coding and non-coding strands suggesting that multiple transcription factors are likely involved. Targeting of putative DNA-Protein binding sites contained within the ASE by gel shift, transfection and mutagenesis studies revealed the importance of several AP-1-like binding sites in governing high levels of Plp gene expression in oligodendrocytes. Our results suggest that factors, which bind to these sites, form the core of a multiProtein complex that assembles on the ASE and ultimately affects the temporal regulation of the gene in oligodendrocytes.
