Phase Variation in Helicobacter pylori Lipopolysaccharide

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Bibliographische Detailangaben
Zeitschriftentitel:	Infection and Immunity
Personen und Körperschaften:	Appelmelk, B. J., Shiberu, B., Trinks, C., Tapsi, N., Zheng, P. Y., Verboom, T., Maaskant, J., Hokke, C. H., Schiphorst, W. E. C. M., Blanchard, D., Simoons-Smit, I. M., van den Eijnden, D. H., Vandenbroucke-Grauls, C. M. J. E.
In:	Infection and Immunity, 66, 1998, 1, S. 70-76
Format:	E-Article
Sprache:	Englisch
veröffentlicht:	American Society for Microbiology
Schlagwörter:	Infectious Diseases Immunology Microbiology Parasitology

Details
Zusammenfassung:	<jats:title>ABSTRACT</jats:title> <jats:p> <jats:italic>Helicobacter pylori</jats:italic> NCTC 11637 lipopolysaccharide (LPS) expresses the human blood group antigen Lewis x (Le <jats:sup>x</jats:sup> ) in a polymeric form. Le <jats:sup>x</jats:sup> is β- <jats:sc>d</jats:sc> -galactose-(1-4)-[α- <jats:sc>l</jats:sc> -fucose-(1-3)]-β- <jats:sc>d</jats:sc> -acetylglucosamine. Schematically the LPS structure is (Le <jats:sup>x</jats:sup> ) <jats:sub> <jats:italic>n</jats:italic> </jats:sub> -core-lipid A. In this report, we show that Le <jats:sup>x</jats:sup> expression is not a stable trait but that LPS displays a high frequency (0.2 to 0.5%) of phase variation, resulting in the presence of several LPS variants in one bacterial cell population. One type of phase variation implied the loss of α1,3-linked fucose, resulting in variants that expressed nonsubstituted polylactosamines (also called the i antigen), i.e., Le <jats:sup>x</jats:sup> minus fucose; LPS: (lactosamine) <jats:sub> <jats:italic>n</jats:italic> </jats:sub> -core-lipid A. The switch of Le <jats:sup>x</jats:sup> to i antigen was reversible. A second group of variants arose by loss of polymeric main chain which resulted in expression of monomeric Le <jats:sup>y</jats:sup> ; LPS: (Le <jats:sup>y</jats:sup> )-core-lipid A. A third group of variants arose by acquisition of α1,2-linked fucose which hence expressed Le <jats:sup>x</jats:sup> plus Le <jats:sup>y</jats:sup> ; LPS: (Le <jats:sup>y</jats:sup> )(Le <jats:sup>x</jats:sup> ) <jats:sub> <jats:italic>n</jats:italic> </jats:sub> -core-lipid A. The second and third group of variants switched back to the parental phenotype [(Le <jats:sup>x</jats:sup> ) <jats:sub> <jats:italic>n</jats:italic> </jats:sub> -core-lipid A] in lower frequencies. Part of the variation can be ascribed to altered expression levels of glycosyltransferase levels as assessed by assaying the activities of galactosyl-, fucosyl-, and <jats:italic>N</jats:italic> -acetylglucosaminyltransferases. Clearly phase variation increases the heterogeneity of <jats:italic>H. pylori</jats:italic> , and this process may be involved in generating the very closely related yet genetically slightly different strains that have been isolated from one patient. </jats:p>
Umfang:	70-76
ISSN:	0019-9567 1098-5522
DOI:	10.1128/iai.66.1.70-76.1998