Thu, 21 Aug 2008 15:38:04 BST CiteULike: xingxu Kersulyte http://www.citeulike.org/user/xingxu/author/Kersulyte CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/xingxu/article/2626651 <i>Science (New York, N.Y.), Vol. 297, No. 5581. (26 July 2002), pp. 573-578.</i><br /><br />Helicobacter pylori adherence in the human gastric mucosa involves specific bacterial adhesins and cognate host receptors. Here, we identify sialyl-dimeric-Lewis x glycosphingolipid as a receptor for H. pylori and show that H. pylori infection induced formation of sialyl-Lewis x antigens in gastric epithelium in humans and in a Rhesus monkey. The corresponding sialic acid-binding adhesin (SabA) was isolated with the "retagging" method, and the underlying sabA gene (JHP662/HP0725) was identified. The ability of many H. pylori strains to adhere to sialylated glycoconjugates expressed during chronic inflammation might thus contribute to virulence and the extraordinary chronicity of H. pylori infection. Helicobacter pylori SabA adhesin in persistent infection and chronic inflammation. J Mahdavi B Sondén M Hurtig FO Olfat L Forsberg N Roche J Angstrom T Larsson S Teneberg KA Karlsson S Altraja T Wadström D Kersulyte DE Berg A Dubois C Petersson KE Magnusson T Norberg F Lindh BB Lundskog A Arnqvist L Hammarström T Borén doi:10.1126/science.1069076 Science (New York, N.Y.), Vol. 297, No. 5581. (26 July 2002), pp. 573-578. 2008-04-03T16:08:33-00:00 2002 Science (New York, N.Y.) 1095-9203 297 5581 573 578 pylori http://www.citeulike.org/user/xingxu/article/2425342 <i>Science, Vol. 279, No. 5349. (16 January 1998), pp. 373-377.</i><br /><br />10.1126/science.279.5349.373 Helicobacter pylori Adhesin Binding Fucosylated Histo-Blood Group Antigens Revealed by Retagging Dag Ilver Anna Arnqvist Johan Ogren Inga-Maria Frick Dangeruta Kersulyte Engin Incecik Douglas Berg Antonello Covacci Lars Engstrand Thomas Boren doi:10.1126/science.279.5349.373 Science, Vol. 279, No. 5349. (16 January 1998), pp. 373-377. 2008-02-25T11:35:33-00:00 1998 Science 279 5349 373 377 baba pylori http://www.citeulike.org/user/xingxu/article/2320398 <i>Proceedings of the National Academy of Sciences, Vol. 101, No. 48. (30 November 2004), pp. 16923-16928.</i><br /><br />Heterogeneity among Helicobacter pylori strains in gastric epithelial adherence is postulated to contribute to pathogen fitness in the physiologically diverse human population. H. pylori adherence to ABO and Lewis b (Leb) blood group antigens in the human stomach is mediated by the blood group antigen-binding adhesin BabA. Approximately 70% of Swedish and U.S. H. pylori clinical isolates exhibit Leb binding, but here we show that the babA gene is present in each of 10 Leb-nonbinding strains. Fluorescence microscopy identified occasional bacterial cells with a Leb-binding phenotype in populations of Leb-nonbinding strains. Thus, nonbinding seemed to be a metastable phenotype. To model metastable transition into the virulence-associated Leb-binding mode, Leb-binding clones were isolated from nonadherent strains by panning with Leb-magnetic beads and characterized. Strain 17875 has two babA genes, babA1 (silent) and babA2 (expressed). We found that a babA2-cam derivative of strain 17875 regained Leb binding by recombination of the formerly silent babA1 gene into the expressed and partially homologous babB locus. The chimeric BabB/A adhesin binds Leb with an affinity similar to that of wild-type BabA adhesin, but its expression level was lower and was subject to phase variation through slipped-strand mispairing. Equivalent results were obtained with strain NCTC11638. We propose that adhesin metastability and heterogeneity contributes to bacterial fitness and results in some clones having potential for periodic activation and deactivation of virulence appropriate for intensity of the host response to infection. 10.1073/pnas.0404817101 From The Cover: Metastability of Helicobacter pylori bab adhesin genes and dynamics in Lewis b antigen binding Anna Backstrom Carina Lundberg Dangeruta Kersulyte Douglas Berg Thomas Boren Anna Arnqvist doi:10.1073/pnas.0404817101 Proceedings of the National Academy of Sciences, Vol. 101, No. 48. (30 November 2004), pp. 16923-16928. 2008-02-01T19:21:42-00:00 2004 Proceedings of the National Academy of Sciences 101 48 16923 16928 baba pylori