Bactericidal activity of two IgG2a murine monoclonal antibodies with distinct fine specificities for group B Neisseria meningitidis capsular polysaccharide.
To analyze the fine specificity of the protective IgG response for the capsule of group B Neisseria meningitidis (Men B) induced after immunization with live bacteria, two specific IgG2a monoclonal antibodies (mAb) have been generated from hyperimmunized Balb/c and NZB mice (101C11 and 30H12). They specifically recognize in direct and competitive binding assays the capsular polysaccharides of Men B and Escherichia coli k1 on condition that the length of the polysaccharidic chain is sufficient to make a conformational structure (more than 15 monomers of alpha (2-->8) linked N-acetyl neuraminic acid). They do not interact with group A and group C Neisseria meningitidis polysaccharides in ELISA. A chemical derivative of the Men B polysaccharide, the N-propionylated Men B polysaccharide, considered as mimicking a unique bactericidal epitope on the surface of Men B is recognized by 101C11 but not by 30H12. The two mAb have, in vitro, a specific bactericidal activity against live Men B which do not seem serotype specific. Moreover, the killing of Men B mediated by 30H12 can be neutralized by an anti-idiotypic mAb (216F11) generated from A/J mice, immunized with polymerized 30H12. These data show that at least two distinct bactericidal epitopes exist on the surface of the Men B capsule.
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Immunology Research Department, Pasteur Mérieux Sérums et Vaccins, Marcy l'Etoile, France.
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D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000942:Antigens, Bacterial / Q000276:immunology*; D016667:Bacterial Capsules; D001667:Binding, Competitive; D002236:Carbohydrate Conformation; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology*; D051379:Mice; D008805:Mice, Inbred A / Q000276:immunology; D008807:Mice, Inbred BALB C / Q000276:immunology; D008814:Mice, Inbred NZB / Q000276:immunology; D008819:Mice, Nude / Q000276:immunology; D009345:Neisseria meningitidis / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000276:immunology*
D000888:Antibodies, Anti-Idiotypic; D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D000939:Epitopes; D007074:Immunoglobulin G; D011135:Polysaccharides, Bacterial; C036962:capsular polysaccharide K1; C039455:capsular polysaccharide, meningococcal group B