Identification of cell-surface mannans in a virulent Helicobacter pylori strain

Abstract

With the intent of contributing to a carbohydrate-based vaccine against the gastroduodenal pathogen, Helicobacter pylori, we report here the structure of cell-surface mannans obtained from a virulent strain. Unlike other wild-type strains, this strain was found to express in good quantities this polysaccharide in vitro. Structural analysis revealed a branched mannan formed by a backbone of alpha-(1-->6)-linked mannopyranosyl residues with approximately 80% branching at the O-2 position. The branches were composed of O-2-linked Man residues in both alpha- and beta-configurations: [abstract: see text]. In addition, this strain also expressed cell-surface emblematic H. pylori lipopolysaccharides (LPS) containing partially fucosylated polyLacNAc O-chains. Affinity assays with polymyxin-B and concanavalin A revealed no association between the mannan and the LPS. The described mannans may be implicated in the mediation of host-microbial interactions and immunological modulation.

The relationship between the structural characteristics of lactobacilli-EPS and its ability to induce apoptosis in colon cancer cells in vitro

“…Furthermore, NMR chemical shifts were determined as described in literature 41,69 by performing 1 H-NMR, COSY and NOESY NMR analysis. Generally, the 1 H NMR spectrum of a polysaccharide can be divided into three main regions: the anomeric region (δ 4.5–5.5), the ring proton region (δ 3.1–4.5) and the alkyl region (δ 1.2–2.3) 70 .…”

Sweet-talk: role of host glycosylation in bacterial pathogenesis of the gastrointestinal tract

“…Although the H pylori –TFF1 interaction appears well-founded, recognition by TFF1 has been ascribed to Glc- and Man-related structures within H pylori LPS by in vitro testing 89. However, this requires further examination because the sugar Man is absent from this LPS,40 44 but is present in bacterial cell surface mannans which co-purify with LPS 96…”

“…Surfactant protein D (SP-D), a member of the collectin family, is a C-type lectin that is found in mucus-secreting cells within gastric pits and with maximal expression at the luminal surface 97 98. Levels of expression of SP-D are significantly increased in H pylori -associated antral gastritis compared with normal human gastric mucosa, and co-localises with infecting H pylori bacteria 96 . SP-D −/− mice are more susceptible to Helicobacter colonisation, and exhibit decreased inflammation and immune response to infection, emphasising the important influence on the establishment of infection 99.…”

Is it possible to determine formation processes of organic deposits through polysaccharides? Pilot study from the prehistoric site in Brandýs nad Labem, Czech Republic

“…In addition, high amounts of both arabinose and xylose in beech and oak litter were confirmed by Sariyildiz and Anderson (2003). As regards microbial saccharides, higher amounts of mannose (Elloway et al, 2004; Ferreira et al, 2010; Geurtsen et al, 2009; Gruden-Movsesijan and Milosavljevic, 2006) and both galactose and mannose stated Moreira et al (2003) and Chowdhury et al (2011). In terms of human saccharides, irrespectively of the well-known fact that humans do not possess a functional gene for l -gulonolactone oxidase in ascorbic acid biosynthesis (Kim et al, 2012), l -rhamnose occurs in blood and urine (Fujii et al, 2001), N -acetyl- d -glucosamine in gastrointestinal tract (Kompella and Lee, 2001), and l -fucose in various human organs (Leck and Wiese, 2004).…”