The Experts below are selected from a list of 18 Experts worldwide ranked by ideXlab platform
Mitsuomi Hirashima - One of the best experts on this subject based on the ideXlab platform.
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regulation of galectin 9 expression and release in jurkat t cell line cells
Glycobiology, 2002Co-Authors: Sophie Chabot, Ryoji Matsumoto, Masako Seki, Yumiko Kashio, Yukako Shirato, Kazuhiro Nakamura, Nozomu Nishi, Takanori Nakamura, Mitsuomi HirashimaAbstract:Ecalectin/galectin-9 was recently described as a novel eosinophil chemoattractant highly expressed in immune tissues. We investigated the regulation of galectin-9 expression and release in Jurkat (a T cell line) cells. We demonstrated that medium and long-sized galectin-9 isoforms were constitutively expressed, and phorbol 12-myriastate 13-acetate (PMA) upregulated the level of galectin-9 mRNA in Jurkat cells. Western blotting and flow cytometry analyses revealed that PMA stimulation resulted in the upregulation of both intracellular and surface galectin-9 protein. The stimulated Jurkat cells simultaneously released evident eosinophil chemoattractant activity (ECA). Main ECA was adsorbed by both lactose and anti-galectin-9 antibody affinity column, suggesting that the ECA was ascribed to galectin-9. When Jurkat cells were stimulated with PMA in the presence of a BB94, a matrix metalloproteinase (MMP) inhibitor, but not tissue inhibitor of metalloproteinase-1 (TIMP-1), the release of galectin-9 was suppressed in a dose-dependent manner. We further found that calphostin c, a protein kinase c (PKC) inhibitor, weakly but significantly suppressed the release of galectin-9. The present data suggested that galectin-9 production in Jurkat cells is provoked by the stimulation with PMA and that some MMP and PKC is, at least, partly involved in the release of galectin-9 from Jurkat cells.
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requirement of divalent galactoside binding activity of Ecalectin galectin 9 for eosinophil chemoattraction
Journal of Biological Chemistry, 2000Co-Authors: Nobuko Matsushita, Ryoji Matsumoto, Masako Seki, Nozomu Nishi, Takanori Nakamura, Ichiro Kuwabara, Futong Liu, Yuiro Hata, Mitsuomi HirashimaAbstract:We have previously isolated and cloned a novel eosinophil chemoattractant (ECA) from a human T-cell-derived expression library. This ECA, termed Ecalectin, is a variant of human galectin-9, a member of a beta-galactoside binding animal lectin family, which contains two conserved carbohydrate recognition domains (CRDs). In the present study, we addressed whether carbohydrate binding activity is required for the ECA activity of Ecalectin and whether both CRDs are essential for this activity. Recombinant full-length wild-type Ecalectin (Ecalectin-WT) and N-terminal and C-terminal CRD (Ecalectin-NT and -CT, respectively) were generated. All of these recombinant proteins exhibited affinity for lactose, a property shared by galectins, but Ecalectin-WT exhibited substantially higher hemagglutination activities than Ecalectin-NT and -CT. Furthermore, Ecalectin-WT showed over 100-fold higher ECA activity than Ecalectin-NT and -CT; combination of recombinant domain fragments did not reconstitute the ECA and hemagglutination activities of the full-length protein. ECA activity of Ecalectin-WT was inhibited by lactose in a dose-dependent manner. Site-directed mutation of positions Arg(65) of Ecalectin-NT and Arg(239) of Ecalectin-CT to an aspartic acid residue resulted in the loss of both lactose-binding and ECA activities. We conclude that divalent galactoside-binding activity is required for eosinophil chemoattraction by Ecalectin.
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human Ecalectin a variant of human galectin 9 is a novel eosinophil chemoattractant produced by t lymphocytes
Journal of Biological Chemistry, 1998Co-Authors: Ryoji Matsumoto, Hiroyuki Matsumoto, Masako Seki, Mitsumi Hata, Yusuke Asano, Shiro Kanegasaki, R L Stevens, Mitsuomi HirashimaAbstract:Abstract A 1.6-kilobase pair cDNA was isolated from a human T-cell-derived expression library that encodes a novel eosinophil chemoattractant (designated Ecalectin) expressed during allergic and parasitic responses. Based on its deduced amino acid sequence, Ecalectin is a 36-kDa protein consisting of 323 amino acids. Although Ecalectin lacks a hydrophobic signal peptide, it is secreted from mammalian cells. Ecalectin is not related to any known cytokine or chemokine but rather is a variant of human galectin-9, a member of the large family of animal lectins that have affinity for β-galactosides. Recombinant Ecalectin, expressed in COS cells and insect cells, exhibited potent eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo in a dose-dependent manner but not neutrophils, lymphocytes, or monocytes. The finding that the Ecalectin transcript is present in abundance in various lymphatic tissues and that its expression increases substantially in antigen-activated peripheral blood mononuclear cells suggests that Ecalectin is an important T-cell-derived regulator of eosinophil recruitment in tissues during inflammatory reactions. We believe that this is the first report of the expression of an immunoregulatory galectin expressed by a T-cell line that is selective for eosinophils.
Ryoji Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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regulation of galectin 9 expression and release in jurkat t cell line cells
Glycobiology, 2002Co-Authors: Sophie Chabot, Ryoji Matsumoto, Masako Seki, Yumiko Kashio, Yukako Shirato, Kazuhiro Nakamura, Nozomu Nishi, Takanori Nakamura, Mitsuomi HirashimaAbstract:Ecalectin/galectin-9 was recently described as a novel eosinophil chemoattractant highly expressed in immune tissues. We investigated the regulation of galectin-9 expression and release in Jurkat (a T cell line) cells. We demonstrated that medium and long-sized galectin-9 isoforms were constitutively expressed, and phorbol 12-myriastate 13-acetate (PMA) upregulated the level of galectin-9 mRNA in Jurkat cells. Western blotting and flow cytometry analyses revealed that PMA stimulation resulted in the upregulation of both intracellular and surface galectin-9 protein. The stimulated Jurkat cells simultaneously released evident eosinophil chemoattractant activity (ECA). Main ECA was adsorbed by both lactose and anti-galectin-9 antibody affinity column, suggesting that the ECA was ascribed to galectin-9. When Jurkat cells were stimulated with PMA in the presence of a BB94, a matrix metalloproteinase (MMP) inhibitor, but not tissue inhibitor of metalloproteinase-1 (TIMP-1), the release of galectin-9 was suppressed in a dose-dependent manner. We further found that calphostin c, a protein kinase c (PKC) inhibitor, weakly but significantly suppressed the release of galectin-9. The present data suggested that galectin-9 production in Jurkat cells is provoked by the stimulation with PMA and that some MMP and PKC is, at least, partly involved in the release of galectin-9 from Jurkat cells.
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requirement of divalent galactoside binding activity of Ecalectin galectin 9 for eosinophil chemoattraction
Journal of Biological Chemistry, 2000Co-Authors: Nobuko Matsushita, Ryoji Matsumoto, Masako Seki, Nozomu Nishi, Takanori Nakamura, Ichiro Kuwabara, Futong Liu, Yuiro Hata, Mitsuomi HirashimaAbstract:We have previously isolated and cloned a novel eosinophil chemoattractant (ECA) from a human T-cell-derived expression library. This ECA, termed Ecalectin, is a variant of human galectin-9, a member of a beta-galactoside binding animal lectin family, which contains two conserved carbohydrate recognition domains (CRDs). In the present study, we addressed whether carbohydrate binding activity is required for the ECA activity of Ecalectin and whether both CRDs are essential for this activity. Recombinant full-length wild-type Ecalectin (Ecalectin-WT) and N-terminal and C-terminal CRD (Ecalectin-NT and -CT, respectively) were generated. All of these recombinant proteins exhibited affinity for lactose, a property shared by galectins, but Ecalectin-WT exhibited substantially higher hemagglutination activities than Ecalectin-NT and -CT. Furthermore, Ecalectin-WT showed over 100-fold higher ECA activity than Ecalectin-NT and -CT; combination of recombinant domain fragments did not reconstitute the ECA and hemagglutination activities of the full-length protein. ECA activity of Ecalectin-WT was inhibited by lactose in a dose-dependent manner. Site-directed mutation of positions Arg(65) of Ecalectin-NT and Arg(239) of Ecalectin-CT to an aspartic acid residue resulted in the loss of both lactose-binding and ECA activities. We conclude that divalent galactoside-binding activity is required for eosinophil chemoattraction by Ecalectin.
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human Ecalectin a variant of human galectin 9 is a novel eosinophil chemoattractant produced by t lymphocytes
Journal of Biological Chemistry, 1998Co-Authors: Ryoji Matsumoto, Hiroyuki Matsumoto, Masako Seki, Mitsumi Hata, Yusuke Asano, Shiro Kanegasaki, R L Stevens, Mitsuomi HirashimaAbstract:Abstract A 1.6-kilobase pair cDNA was isolated from a human T-cell-derived expression library that encodes a novel eosinophil chemoattractant (designated Ecalectin) expressed during allergic and parasitic responses. Based on its deduced amino acid sequence, Ecalectin is a 36-kDa protein consisting of 323 amino acids. Although Ecalectin lacks a hydrophobic signal peptide, it is secreted from mammalian cells. Ecalectin is not related to any known cytokine or chemokine but rather is a variant of human galectin-9, a member of the large family of animal lectins that have affinity for β-galactosides. Recombinant Ecalectin, expressed in COS cells and insect cells, exhibited potent eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo in a dose-dependent manner but not neutrophils, lymphocytes, or monocytes. The finding that the Ecalectin transcript is present in abundance in various lymphatic tissues and that its expression increases substantially in antigen-activated peripheral blood mononuclear cells suggests that Ecalectin is an important T-cell-derived regulator of eosinophil recruitment in tissues during inflammatory reactions. We believe that this is the first report of the expression of an immunoregulatory galectin expressed by a T-cell line that is selective for eosinophils.
Masako Seki - One of the best experts on this subject based on the ideXlab platform.
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regulation of galectin 9 expression and release in jurkat t cell line cells
Glycobiology, 2002Co-Authors: Sophie Chabot, Ryoji Matsumoto, Masako Seki, Yumiko Kashio, Yukako Shirato, Kazuhiro Nakamura, Nozomu Nishi, Takanori Nakamura, Mitsuomi HirashimaAbstract:Ecalectin/galectin-9 was recently described as a novel eosinophil chemoattractant highly expressed in immune tissues. We investigated the regulation of galectin-9 expression and release in Jurkat (a T cell line) cells. We demonstrated that medium and long-sized galectin-9 isoforms were constitutively expressed, and phorbol 12-myriastate 13-acetate (PMA) upregulated the level of galectin-9 mRNA in Jurkat cells. Western blotting and flow cytometry analyses revealed that PMA stimulation resulted in the upregulation of both intracellular and surface galectin-9 protein. The stimulated Jurkat cells simultaneously released evident eosinophil chemoattractant activity (ECA). Main ECA was adsorbed by both lactose and anti-galectin-9 antibody affinity column, suggesting that the ECA was ascribed to galectin-9. When Jurkat cells were stimulated with PMA in the presence of a BB94, a matrix metalloproteinase (MMP) inhibitor, but not tissue inhibitor of metalloproteinase-1 (TIMP-1), the release of galectin-9 was suppressed in a dose-dependent manner. We further found that calphostin c, a protein kinase c (PKC) inhibitor, weakly but significantly suppressed the release of galectin-9. The present data suggested that galectin-9 production in Jurkat cells is provoked by the stimulation with PMA and that some MMP and PKC is, at least, partly involved in the release of galectin-9 from Jurkat cells.
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requirement of divalent galactoside binding activity of Ecalectin galectin 9 for eosinophil chemoattraction
Journal of Biological Chemistry, 2000Co-Authors: Nobuko Matsushita, Ryoji Matsumoto, Masako Seki, Nozomu Nishi, Takanori Nakamura, Ichiro Kuwabara, Futong Liu, Yuiro Hata, Mitsuomi HirashimaAbstract:We have previously isolated and cloned a novel eosinophil chemoattractant (ECA) from a human T-cell-derived expression library. This ECA, termed Ecalectin, is a variant of human galectin-9, a member of a beta-galactoside binding animal lectin family, which contains two conserved carbohydrate recognition domains (CRDs). In the present study, we addressed whether carbohydrate binding activity is required for the ECA activity of Ecalectin and whether both CRDs are essential for this activity. Recombinant full-length wild-type Ecalectin (Ecalectin-WT) and N-terminal and C-terminal CRD (Ecalectin-NT and -CT, respectively) were generated. All of these recombinant proteins exhibited affinity for lactose, a property shared by galectins, but Ecalectin-WT exhibited substantially higher hemagglutination activities than Ecalectin-NT and -CT. Furthermore, Ecalectin-WT showed over 100-fold higher ECA activity than Ecalectin-NT and -CT; combination of recombinant domain fragments did not reconstitute the ECA and hemagglutination activities of the full-length protein. ECA activity of Ecalectin-WT was inhibited by lactose in a dose-dependent manner. Site-directed mutation of positions Arg(65) of Ecalectin-NT and Arg(239) of Ecalectin-CT to an aspartic acid residue resulted in the loss of both lactose-binding and ECA activities. We conclude that divalent galactoside-binding activity is required for eosinophil chemoattraction by Ecalectin.
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human Ecalectin a variant of human galectin 9 is a novel eosinophil chemoattractant produced by t lymphocytes
Journal of Biological Chemistry, 1998Co-Authors: Ryoji Matsumoto, Hiroyuki Matsumoto, Masako Seki, Mitsumi Hata, Yusuke Asano, Shiro Kanegasaki, R L Stevens, Mitsuomi HirashimaAbstract:Abstract A 1.6-kilobase pair cDNA was isolated from a human T-cell-derived expression library that encodes a novel eosinophil chemoattractant (designated Ecalectin) expressed during allergic and parasitic responses. Based on its deduced amino acid sequence, Ecalectin is a 36-kDa protein consisting of 323 amino acids. Although Ecalectin lacks a hydrophobic signal peptide, it is secreted from mammalian cells. Ecalectin is not related to any known cytokine or chemokine but rather is a variant of human galectin-9, a member of the large family of animal lectins that have affinity for β-galactosides. Recombinant Ecalectin, expressed in COS cells and insect cells, exhibited potent eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo in a dose-dependent manner but not neutrophils, lymphocytes, or monocytes. The finding that the Ecalectin transcript is present in abundance in various lymphatic tissues and that its expression increases substantially in antigen-activated peripheral blood mononuclear cells suggests that Ecalectin is an important T-cell-derived regulator of eosinophil recruitment in tissues during inflammatory reactions. We believe that this is the first report of the expression of an immunoregulatory galectin expressed by a T-cell line that is selective for eosinophils.
Yusuke Asano - One of the best experts on this subject based on the ideXlab platform.
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human Ecalectin a variant of human galectin 9 is a novel eosinophil chemoattractant produced by t lymphocytes
Journal of Biological Chemistry, 1998Co-Authors: Ryoji Matsumoto, Hiroyuki Matsumoto, Masako Seki, Mitsumi Hata, Yusuke Asano, Shiro Kanegasaki, R L Stevens, Mitsuomi HirashimaAbstract:Abstract A 1.6-kilobase pair cDNA was isolated from a human T-cell-derived expression library that encodes a novel eosinophil chemoattractant (designated Ecalectin) expressed during allergic and parasitic responses. Based on its deduced amino acid sequence, Ecalectin is a 36-kDa protein consisting of 323 amino acids. Although Ecalectin lacks a hydrophobic signal peptide, it is secreted from mammalian cells. Ecalectin is not related to any known cytokine or chemokine but rather is a variant of human galectin-9, a member of the large family of animal lectins that have affinity for β-galactosides. Recombinant Ecalectin, expressed in COS cells and insect cells, exhibited potent eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo in a dose-dependent manner but not neutrophils, lymphocytes, or monocytes. The finding that the Ecalectin transcript is present in abundance in various lymphatic tissues and that its expression increases substantially in antigen-activated peripheral blood mononuclear cells suggests that Ecalectin is an important T-cell-derived regulator of eosinophil recruitment in tissues during inflammatory reactions. We believe that this is the first report of the expression of an immunoregulatory galectin expressed by a T-cell line that is selective for eosinophils.
R L Stevens - One of the best experts on this subject based on the ideXlab platform.
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human Ecalectin a variant of human galectin 9 is a novel eosinophil chemoattractant produced by t lymphocytes
Journal of Biological Chemistry, 1998Co-Authors: Ryoji Matsumoto, Hiroyuki Matsumoto, Masako Seki, Mitsumi Hata, Yusuke Asano, Shiro Kanegasaki, R L Stevens, Mitsuomi HirashimaAbstract:Abstract A 1.6-kilobase pair cDNA was isolated from a human T-cell-derived expression library that encodes a novel eosinophil chemoattractant (designated Ecalectin) expressed during allergic and parasitic responses. Based on its deduced amino acid sequence, Ecalectin is a 36-kDa protein consisting of 323 amino acids. Although Ecalectin lacks a hydrophobic signal peptide, it is secreted from mammalian cells. Ecalectin is not related to any known cytokine or chemokine but rather is a variant of human galectin-9, a member of the large family of animal lectins that have affinity for β-galactosides. Recombinant Ecalectin, expressed in COS cells and insect cells, exhibited potent eosinophil chemoattractant activity and attracted eosinophils in vitro and in vivo in a dose-dependent manner but not neutrophils, lymphocytes, or monocytes. The finding that the Ecalectin transcript is present in abundance in various lymphatic tissues and that its expression increases substantially in antigen-activated peripheral blood mononuclear cells suggests that Ecalectin is an important T-cell-derived regulator of eosinophil recruitment in tissues during inflammatory reactions. We believe that this is the first report of the expression of an immunoregulatory galectin expressed by a T-cell line that is selective for eosinophils.