Flow cytometric analysis of the localization of Helicobacter pylori antigens during different growth phases

Blom, K

doi:10.1016/s0928-8244(00)00250-9

Cited by 11 publications

(12 citation statements)

References 20 publications

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“…Still, although the bacterial cells induce a strong CL response, no effect with HP-NAP was obtained in this assay. This might be due to the fact that very limited amounts of HP-NAP are present on the bacterial surface (48). It was recently shown that HP-NAP activates the extracellular regulated kinase and p38 mitogen-activated protein kinase in human neutrophils, and these events are essential for the HP-NAP-induced neutrophil respiratory burst and for the chemotaxis and adhesion of the neutrophils (47).…”

Section: Discussionmentioning

confidence: 99%

The Sialic Acid Binding SabA Adhesin of Helicobacter pylori Is Essential for Nonopsonic Activation of Human Neutrophils

Unemo

Aspholm-Hurtig

Ilver

et al. 2005

Journal of Biological Chemistry

106

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Infiltration of neutrophils and monocytes into the gastric mucosa is a hallmark of chronic gastritis caused by Helicobacter pylori. Certain H. pylori strains nonopsonized stimulate neutrophils to production of reactive oxygen species causing oxidative damage of the gastric epithelium. Here, the contribution of some H. pylori virulence factors, the blood group antigen-binding adhesin BabA, the sialic acid-binding adhesin SabA, the neutrophil-activating protein HP-NAP, and the vacuolating cytotoxin VacA, to the activation of human neutrophils in terms of adherence, phagocytosis, and oxidative burst was investigated. Neutrophils were challenged with wild type bacteria and isogenic mutants lacking BabA, SabA, HP-NAP, or VacA. Mutant and wild type strains lacking SabA had no neutrophil-activating capacity, demonstrating that binding of H. pylori to sialylated neutrophil receptors plays a pivotal initial role in the adherence and phagocytosis of the bacteria and the induction of the oxidative burst. The link between receptor binding and oxidative burst involves a G-proteinlinked signaling pathway and downstream activation of phosphatidylinositol 3-kinase as shown by experiments using signal transduction inhibitors. Collectively our data suggest that the sialic acid-binding SabA adhesin is a prerequisite for the nonopsonic activation of human neutrophils and, thus, is a virulence factor important for the pathogenesis of H. pylori infection.

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Section: Discussionmentioning

confidence: 99%

The Sialic Acid Binding SabA Adhesin of Helicobacter pylori Is Essential for Nonopsonic Activation of Human Neutrophils

Unemo

Aspholm-Hurtig

Ilver

et al. 2005

Journal of Biological Chemistry

106

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“…Two ganglioside binding proteins of H. pylori have been identified, the SabA adhesin and the NeuAc␣3Gal␤4 GlcNAc␤3Gal␤4GlcNAc␤-binding neutrophil-activating protein HPNAP (19,36). HPNAP is a major immunogen of H. pylori (29) and is to some extent associated with the bacterial cell surface (2). Since whole bacterial cells also bind to NeuAc␣3Gal␤4GlcNAc␤3Gal␤4GlcNAc␤-terminated glycosphingolipids, it is tempting to speculate that this interaction is due to surface-associated HPNAP.…”

Section: Discussionmentioning

confidence: 99%

Helicobacter pylori and Complex Gangliosides

Roche¹,

Ångström²,

Hurtig

et al. 2004

Infect Immun

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“…H. pylori expresses a large amount of NapA, especially in vivo (6), so that NapA is a major antigen in the human immune response to H. pylori (2,33). NapA is a cytosolic protein expressed by virtually all H. pylori isolates, and it is oftentimes detected in the culture medium after bacterial growth (7,36).…”

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confidence: 99%

Dual Roles of Helicobacter pylori NapA in Inducing and Combating Oxidative Stress

et al. 2006

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Neutrophil-activating protein (NapA) has been well documented to play roles in human neutrophil recruitment and in stimulating host cell production of reactive oxygen intermediates (ROI). A separate role for NapA in combating oxidative stress within H. pylori was implied by studies of various H. pylori mutant strains. Here, physiological analysis of a napA strain was the approach used to assess the iron-sequestering and stress resistance roles of NapA, its role in preventing oxidative DNA damage, and its importance to mouse colonization. The napA strain was more sensitive to oxidative stress reagents and to oxygen, and it contained fourfold more intracellular free iron and more damaged DNA than the parent strain. Pure, iron-loaded NapA bound to DNA, but native NapA did not, presumably linking iron levels sensed by NapA to DNA damage protection. Despite its in vitro phenotype of sensitivity to oxidative stress, the napA strain showed normal (like that of the wild type) mouse colonization efficiency in the conventional in vivo assay. By use of a modified mouse inoculation protocol whereby nonviable H. pylori is first inoculated into mice, followed by (live) bacterial strain administration, an in vivo role for NapA in colonization efficiency could be demonstrated. NapA is the critical component responsible for inducing host-mediated ROI production, thus inhibiting colonization by the napA strain. An animal colonization experiment with a mixed-strain infection protocol further demonstrated that the napA strain has significantly decreased ability to survive when competing with the wild type. H. pylori NapA has unique and separate roles in gastric pathogenesis.

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Flow cytometric analysis of the localization of Helicobacter pylori antigens during different growth phases

Cited by 11 publications

References 20 publications

The Sialic Acid Binding SabA Adhesin of Helicobacter pylori Is Essential for Nonopsonic Activation of Human Neutrophils

The Sialic Acid Binding SabA Adhesin of Helicobacter pylori Is Essential for Nonopsonic Activation of Human Neutrophils

Helicobacter pylori and Complex Gangliosides

Dual Roles of Helicobacter pylori NapA in Inducing and Combating Oxidative Stress

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