Alterations in Helicobacter pylori outer membrane and outer membrane vesicle-associated lipopoly-saccharides under iron-limiting growth conditions

Outer membrane vesicles (OMVs) shed from the gastroduodenal pathogen Helicobacter pylori have measurable effects on epithelial cell responses. The aim of this study was to determine the effect of iron availability, and its basis, on the extent and nature of lipopolysaccharide (LPS) produced on H. py...

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Bibliographic Details
Published in:Innate immunity (London, England) England), 2008-10, Vol.14 (5), p.279-290
Main Authors: Keenan, JI, Davis, KA, Beaugie, C R, McGovern, J J, Moran, A P
Format: Article
Language:English
Subjects:
Helicobacter pylori
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Summary:Outer membrane vesicles (OMVs) shed from the gastroduodenal pathogen Helicobacter pylori have measurable effects on epithelial cell responses. The aim of this study was to determine the effect of iron availability, and its basis, on the extent and nature of lipopolysaccharide (LPS) produced on H. pylori OMVs and their parental bacterial cells. Electrophoretic, immunoblotting and structural analyses revealed that LPSs of bacterial cells grown under iron-limited conditions were notably shorter than those of bacteria and OMVs obtained from iron-replete conditions. Structural analysis and serological probing showed that LPSs of iron-replete cells and OMVs expressed O-chains of Lewis super(X) with a terminal Lewis super(Y) unit, whereas Lewis super(Y) expression was notably reduced on bacteria and OMVs from iron-limiting conditions. Unlike the O-chain, the core oligosaccharide and lipid A moieties of iron-replete and iron-limited bacteria and their OMVs were similar. Quantitatively, shed OMVs from iron-replete bacteria were found to be LPS-enriched, whereas shed OMVs from iron-limited bacteria had a significantly reduced content of LPS. These differences were linked to bacterial ATP levels. Since iron availability affects the extent and nature of LPS expressed by H.pylori, host iron status may contribute to H.pylori pathogenesis.
ISSN:1753-4259
DOI:10.1177/1753425908096857