Antigenic Variation among Bordetella: Bordetella bronchiseptica strain MO149 expresses a novel o chain that is poorly immunogenic.
The O chain polysaccharide (O PS) of Bordetella bronchiseptica and Bordetella parapertussis lipopolysaccharide is a homopolymer of 2,3-diacetamido-2,3-dideoxygalacturonic acid (GalNAc3NAcA) in which some of the sugars are present as uronamides. The terminal residue contains several unusual modifications. To date, two types of modification have been characterized, and a survey of numerous strains demonstrated that each contained one of these two modification types. Host antibody responses against the O PS are directed against the terminal residue modifications, and there is little cross-reactivity between the two types. This suggests that Bordetella O PS modifications represent a means of antigenic variation. Here we report the characterization of the O PS of B. bronchiseptica strain MO149. It consists of a novel two-sugar repeating unit and a novel terminal residue modification, with the structure Me-4-alpha-L-GalNAc3NAcA-(4-beta-D-GlcNAc3NAcA-4-alpha-L-GalNAc3NAcA-)(5-6)-, which we propose be defined as the B. bronchiseptica O3 PS. We show that the O3 PS is very poorly immunogenic and that the MO149 strain contains a novel wbm (O PS biosynthesis) locus. Thus, there is greater diversity among Bordetella O PSs than previously recognized, which is likely to be a result of selection pressure from host immunity. We also determine experimentally, for the first time, the absolute configuration of the diacetimido-uronic acid sugars in Bordetella O PS.
Vinogradov
Evgeny
E
Institute for Biological Sciences, National Research Council, Ottawa, Ontario K1A 0R6, Canada.
King
Jerry D
JD
Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Pathak
Ashutosh K
AK
Department of Veterinary and Biomedical Science, Pennsylvania State University, University Park, Pennsylvania 16802, United Kingdom.
Harvill
Eric T
ET
Department of Veterinary and Biomedical Science, Pennsylvania State University, University Park, Pennsylvania 16802, United Kingdom.
Preston
Andrew
A
Department of Clinical Veterinary Science, University of Bristol, Langford, North Somerset BS40 5DU, United Kingdom. Electronic address: a.preston@bristol.ac.uk.
D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D016950:Bordetella bronchiseptica / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D002236:Carbohydrate Conformation; D056426:Genetic Loci; D008070:Lipopolysaccharides / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D051379:Mice
D000942:Antigens, Bacterial; D008070:Lipopolysaccharides