Epitope mapping of six monoclonal antibodies recognizing the Shigella dysenteriae type 1 O-antigenic repeating unit expressed in Escherichia coli K-12.
Mouse and rat monoclonal antibodies were generated against lipopolysaccharides expressed in Escherichia coli K-12/Shigella dysenteriae type 1 hybrids and native Shigella dysenteriae type 1 bacteria. Six monoclonal antibodies, all IgM and reacting with the E. coli K-12/Shigella dysenteriae type 1 hybrids, were selected and characterized. The specificities were studied in inhibition experiments using purified native and synthetic saccharides, representing different parts of the S. dysenteriae type 1 tetrasaccharide repeating unit. Three patterns of specificities were seen: (i) MAEC-SD-1 and MAEC-SD-2 recognizing the terminal alpha-D-Galp-(1-->3)-beta-D-GlcpNAc disaccharide as present in an E. coli K-12 class I hybrid strain, (ii) MAEC-SD-11; a class IV specific mAb, recognizing the alpha-L-Rhap-(1-->2)-alpha-D-Galp-(1-->3)-beta-D-GlcpNAc-(1-->tris accharide, and (iii) MAEC-SD-21, MASD-1, MASD-2; all mAbs with class V specificity, recognizing the alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-D-Galp-(1--> trisaccharide. Furthermore, the data strongly suggest that the native repeating unit for S. dysenteriae type 1 is the alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-D-Galp-(1--> 3)-alpha-D-GlcpNAc tetrasaccharide.
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Department of Clinical Bacteriology, Karolinska Institute, Huddinge Hospital, Sweden.
Lindberg
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D000907:Antibodies, Bacterial / Q000276:immunology*; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D002240:Carbohydrate Sequence; D003433:Crosses, Genetic; D000939:Epitopes / Q000276:immunology*; D004926:Escherichia coli / Q000235:genetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019081:O Antigens; D009844:Oligosaccharides / Q000276:immunology*; D011135:Polysaccharides, Bacterial / Q000235:genetics / Q000276:immunology*; D012762:Shigella dysenteriae / Q000235:genetics / Q000276:immunology*
D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D000939:Epitopes; D019081:O Antigens; D009844:Oligosaccharides; D011135:Polysaccharides, Bacterial