The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

Monique Garnier - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Polyclonal, Monoclonal, and Recombinant (Single-Chain Variable Fragment) Antibodies on In Vitro Morphology, Growth, and Metabolism of the Phytopathogenic Mollicute Spiroplasma citri
    2002
    Co-Authors: Sylvie Malembic, Colette Saillard, Joseph M. Bové, Monique Garnier
    Abstract:

    Antibodies are known to affect the morphology, growth, and metabolism of mollicutes and thus may serve as candidate molecules for a Plantibody-based control strategy for plant-pathogenic spiroplasmas and phytoplasmas. Recombinant single-chain variable fragment (scFv) antibodies are easy to engineer and express in plants, but their inhibitory effects on mollicutes have never been evaluated and compared with those of polyclonal and monoclonal antibodies. We describe the morphology, growth, and glucose metabolism of Spiroplasma citri in the presence of polyclonal, monoclonal, and recombinant antibodies directed against the immunodominant membrane protein spiralin. We showed that the scFv antibodies had no effect on S. citri glucose metabolism but were as efficient as polyclonal antibodies in inhibiting S. citri growth in liquid medium. Inhibition of motility was also observed.

  • Effect of Polyclonal, Monoclonal, and Recombinant (Single-Chain Variable Fragment) Antibodies on In Vitro Morphology, Growth, and
    2001
    Co-Authors: Metabolism Phytopathogenic, Sylvie Malembic, Colette Saillard, Joseph M. Bové, Mollicute Spiroplasma, Monique Garnier
    Abstract:

    Antibodies are known to affect the morphology, growth, and metabolism of mollicutes and thus may serve as candidate molecules for a Plantibody-based control strategy for plant-pathogenic spiroplasmas and phyto-plasmas. Recombinant single-chain variable fragment (scFv) antibodies are easy to engineer and express in plants, but their inhibitory effects on mollicutes have never been evaluated and compared with those of polyclonal and monoclonal antibodies. We describe the morphology, growth, and glucose metabolism of Spiroplasma citri in the presence of polyclonal, monoclonal, and recombinant antibodies directed against the immunodominant membrane protein spiralin. We showed that the scFv antibodies had no effect on S. citri glucose metabolism but were as efficient as polyclonal antibodies in inhibiting S. citri growth in liquid medium. Inhibition of motility was also observed. Plant-pathogenic mollicutes include the genus Spiroplasma, comprising organisms culturable in complex artificial media and showing a helical morphology, and the Candidatus genus phytoplasma, containing large numbers of pleiomorphic organ-isms which, until now, have resisted in vitro cultivation (4, 9). Hence, spiroplasmas are the most-studied phytopathogenic mollicutes, and S. citri (23) is the model organism for this important group of plant pathogens. Mollicutes are eubacteria without a cell wall and thus de-limited only by a cytoplasmic membrane. This characteristic has been linked with the fact that metabolism and growth of mollicutes were strongly inhibited by antibodies directe

Yasuyuki Imai - One of the best experts on this subject based on the ideXlab platform.

  • production of hybrid igg iga plantibodies with neutralizing activity against shiga toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.

  • Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.

Katsuhiro Nakanishi - One of the best experts on this subject based on the ideXlab platform.

  • Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1
    2016
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yuki Tobisawa, Kohta Kurohane, Yasuo Niwa
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a ‘‘Plantibody’’. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/ IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These result

  • production of hybrid igg iga plantibodies with neutralizing activity against shiga toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.

  • Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.

Sylvie Malembic - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Polyclonal, Monoclonal, and Recombinant (Single-Chain Variable Fragment) Antibodies on In Vitro Morphology, Growth, and Metabolism of the Phytopathogenic Mollicute Spiroplasma citri
    2002
    Co-Authors: Sylvie Malembic, Colette Saillard, Joseph M. Bové, Monique Garnier
    Abstract:

    Antibodies are known to affect the morphology, growth, and metabolism of mollicutes and thus may serve as candidate molecules for a Plantibody-based control strategy for plant-pathogenic spiroplasmas and phytoplasmas. Recombinant single-chain variable fragment (scFv) antibodies are easy to engineer and express in plants, but their inhibitory effects on mollicutes have never been evaluated and compared with those of polyclonal and monoclonal antibodies. We describe the morphology, growth, and glucose metabolism of Spiroplasma citri in the presence of polyclonal, monoclonal, and recombinant antibodies directed against the immunodominant membrane protein spiralin. We showed that the scFv antibodies had no effect on S. citri glucose metabolism but were as efficient as polyclonal antibodies in inhibiting S. citri growth in liquid medium. Inhibition of motility was also observed.

  • Effect of Polyclonal, Monoclonal, and Recombinant (Single-Chain Variable Fragment) Antibodies on In Vitro Morphology, Growth, and
    2001
    Co-Authors: Metabolism Phytopathogenic, Sylvie Malembic, Colette Saillard, Joseph M. Bové, Mollicute Spiroplasma, Monique Garnier
    Abstract:

    Antibodies are known to affect the morphology, growth, and metabolism of mollicutes and thus may serve as candidate molecules for a Plantibody-based control strategy for plant-pathogenic spiroplasmas and phyto-plasmas. Recombinant single-chain variable fragment (scFv) antibodies are easy to engineer and express in plants, but their inhibitory effects on mollicutes have never been evaluated and compared with those of polyclonal and monoclonal antibodies. We describe the morphology, growth, and glucose metabolism of Spiroplasma citri in the presence of polyclonal, monoclonal, and recombinant antibodies directed against the immunodominant membrane protein spiralin. We showed that the scFv antibodies had no effect on S. citri glucose metabolism but were as efficient as polyclonal antibodies in inhibiting S. citri growth in liquid medium. Inhibition of motility was also observed. Plant-pathogenic mollicutes include the genus Spiroplasma, comprising organisms culturable in complex artificial media and showing a helical morphology, and the Candidatus genus phytoplasma, containing large numbers of pleiomorphic organ-isms which, until now, have resisted in vitro cultivation (4, 9). Hence, spiroplasmas are the most-studied phytopathogenic mollicutes, and S. citri (23) is the model organism for this important group of plant pathogens. Mollicutes are eubacteria without a cell wall and thus de-limited only by a cytoplasmic membrane. This characteristic has been linked with the fact that metabolism and growth of mollicutes were strongly inhibited by antibodies directe

Yasuo Niwa - One of the best experts on this subject based on the ideXlab platform.

  • Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1
    2016
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yuki Tobisawa, Kohta Kurohane, Yasuo Niwa
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a ‘‘Plantibody’’. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/ IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These result

  • production of hybrid igg iga plantibodies with neutralizing activity against shiga toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.

  • Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1
    2013
    Co-Authors: Katsuhiro Nakanishi, Sanshiro Narimatsu, Shiori Ichikawa, Yasuo Niwa, Yuki Tobisawa, Hirokazu Kobayashi, Kohta Kurohane, Yasuyuki Imai
    Abstract:

    Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “Plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting Plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning.