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

• Author(s): Ferreira, José Alexandre ; Azevedo, N. F. ; Vieira, M. J. ; Figueiredo, C. ; Goodfellow, Brian J. ; Monteiro, Mário A. ; Coimbra, Manuel A.
• Date: 2010
• Persistent ID: http://hdl.handle.net/1822/10689
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Cell-surface glycans; Helicobacter pylori; Lipopolysaccharide; Mannan; Vaccine
• Document Type: Article
• Language: English

Description

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 α-(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 α- and β-configurations: (image) 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.