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PMID:20659286

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Citation

Olofsson, A, Vallström, A, Petzold, K, Tegtmeyer, N, Schleucher, J, Carlsson, S, Haas, R, Backert, S, Wai, SN, Gröbner, G and Arnqvist, A (2010) Biochemical and functional characterization of Helicobacter pylori vesicles. Mol. Microbiol. 77:1539-55

Abstract

Helicobacter pylori can cause peptic ulcer disease and/or gastric cancer. Adhesion of bacteria to the stomach mucosa is an important contributor to the vigour of infection and resulting virulence. H. pylori adheres primarily via binding of BabA adhesins to ABO/Lewis b (Leb) blood group antigens and the binding of SabA adhesins to sialyl-Lewis x/a (sLex/a) antigens. Similar to most Gram-negative bacteria, H. pylori continuously buds off vesicles and vesicles derived from pathogenic bacteria often include virulence-associated factors. Here we biochemically characterized highly purified H. pylori vesicles. Major protein and phospholipid components associated with the vesicles were identified with mass spectroscopy and nuclear magnetic resonance. A subset of virulence factors present was confirmed by immunoblots. Additional functional and biochemical analysis focused on the vesicle BabA and SabA adhesins and their respective interactions to human gastric epithelium. Vesicles exhibit heterogeneity in their protein composition, which were specifically studied in respect to the BabA adhesin. We also demonstrate that the oncoprotein, CagA, is associated with the surface of H. pylori vesicles. Thus, we have explored mechanisms for intimate H. pylori vesicle-host interactions and found that the vesicles carry effector-promoting properties that are important to disease development.

Links

PubMed PMC3068288 Online version:10.1111/j.1365-2958.2010.07307.x

Keywords

Adhesins, Bacterial/metabolism; Antigens, Bacterial/metabolism; Bacterial Adhesion; Bacterial Outer Membrane Proteins/isolation & purification; Bacterial Proteins/metabolism; Gastric Mucosa/microbiology; Helicobacter pylori/pathogenicity; Humans; Phospholipids/analysis; Tissue Culture Techniques; Virulence Factors/isolation & purification

Significance

Annotations

Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status

HELPY:Q9JP55

part_of

GO:0070062: extracellular exosome

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HELPX:Q9JP55

GO:0070062: extracellular vesicular exosome

ECO:0000314:

C

Figure 8 shows immunogold analysis of CagA, demonstrating localization to bacterial vesicle surface.

complete
CACAO 8755

HELPX:Q9JP55

part_of

GO:0070062: extracellular exosome

ECO:0000314: direct assay evidence used in manual assertion

C

Seeded From UniProt

complete

HELP3:D7FE80

incorrect (CACAO)

GO:0070062: extracellular vesicular exosome

ECO:0000314:

C

Figure 4 demonstrates the presence of SabA and other proteins as major phospholipid components in H. pylori vesicles. Figure 6 demonstrates the presence of receptor-binding adhesins like SabA on the surface of H. pylori vesicles. Figure 7 shows the SabA adhesion–receptor specificity operating in the vesicle–tissue interaction.

complete
CACAO 9627

See also

References

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