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Water-induced modulation of Helicobacter pylori virulence properties.

Guimarães NM, Azevedo NF, Vieira MJ, Figueiredo C - Mem. Inst. Oswaldo Cruz (2014)

Bottom Line: While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties.However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system.These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Pathology and Immunology, Medical Faculty, University of Porto, Porto, Portugal.

ABSTRACT
While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium's ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.

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: effect of water exposure on Helicobacter pyloriinduction of interleukin (IL)-8 secretion by host epithelial cells. AGS cellswere infected with H. pylori 26695 inocula that have beenexposed to water for 2 h (Hpw2h), 6 h (Hpw6h), 24 h (Hpw24h) and 48 h (Hpw48h)at a multiplicity of infection of 100. As control, H. pylori26695 that was not exposed to the water was used (Hp). IL-8 productionwas evaluated by ELISA. Graphics represent mean ± standard deviation and arerepresentative of three independent experiments. *: significantly differentfrom uninfected cells; **: significantly different from non-exposed H.pylori (p < 0.05).
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f03: : effect of water exposure on Helicobacter pyloriinduction of interleukin (IL)-8 secretion by host epithelial cells. AGS cellswere infected with H. pylori 26695 inocula that have beenexposed to water for 2 h (Hpw2h), 6 h (Hpw6h), 24 h (Hpw24h) and 48 h (Hpw48h)at a multiplicity of infection of 100. As control, H. pylori26695 that was not exposed to the water was used (Hp). IL-8 productionwas evaluated by ELISA. Graphics represent mean ± standard deviation and arerepresentative of three independent experiments. *: significantly differentfrom uninfected cells; **: significantly different from non-exposed H.pylori (p < 0.05).

Mentions: Influence of water exposure on H. pylori induction of IL-8 secretion by hostcells - H. pylori leads to increased production by the epithelium of theproinflammatory cytokine IL-8 when in close contact with the gastric mucosa (Shimoyama & Crabtree 1998). Becausewater-exposed H. pylori were able to adhere to epithelial cells, westudied the capability of H. pylori to induce inflammation byevaluating the secretion levels of IL-8 from AGS cells infected with H.pylori inocula exposed to water for different time periods (Fig. 3). Results show that H. pyloriwith 2 h and 6 h of water exposure retain the ability to induce IL-8 secretion similarlyto unexposed bacteria. However, after 24 h of exposure, H. pylori areno longer able to induce IL-8 production by AGS cells. Therefore, the case ofinflammation induced by the bacterium appears to be more related to the culturabilitystatus of H. pylori than to the ability of this microorganism to adhereto epithelial cells. In fact, although adhesion to host cells is immediately decreasedafter contact with water, after short time periods (up to 6 h), adhering H.pylori cells are still able to induce pro-inflammatory IL-8 secretion inthese cells.


Water-induced modulation of Helicobacter pylori virulence properties.

Guimarães NM, Azevedo NF, Vieira MJ, Figueiredo C - Mem. Inst. Oswaldo Cruz (2014)

: effect of water exposure on Helicobacter pyloriinduction of interleukin (IL)-8 secretion by host epithelial cells. AGS cellswere infected with H. pylori 26695 inocula that have beenexposed to water for 2 h (Hpw2h), 6 h (Hpw6h), 24 h (Hpw24h) and 48 h (Hpw48h)at a multiplicity of infection of 100. As control, H. pylori26695 that was not exposed to the water was used (Hp). IL-8 productionwas evaluated by ELISA. Graphics represent mean ± standard deviation and arerepresentative of three independent experiments. *: significantly differentfrom uninfected cells; **: significantly different from non-exposed H.pylori (p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4155841&req=5

f03: : effect of water exposure on Helicobacter pyloriinduction of interleukin (IL)-8 secretion by host epithelial cells. AGS cellswere infected with H. pylori 26695 inocula that have beenexposed to water for 2 h (Hpw2h), 6 h (Hpw6h), 24 h (Hpw24h) and 48 h (Hpw48h)at a multiplicity of infection of 100. As control, H. pylori26695 that was not exposed to the water was used (Hp). IL-8 productionwas evaluated by ELISA. Graphics represent mean ± standard deviation and arerepresentative of three independent experiments. *: significantly differentfrom uninfected cells; **: significantly different from non-exposed H.pylori (p < 0.05).
Mentions: Influence of water exposure on H. pylori induction of IL-8 secretion by hostcells - H. pylori leads to increased production by the epithelium of theproinflammatory cytokine IL-8 when in close contact with the gastric mucosa (Shimoyama & Crabtree 1998). Becausewater-exposed H. pylori were able to adhere to epithelial cells, westudied the capability of H. pylori to induce inflammation byevaluating the secretion levels of IL-8 from AGS cells infected with H.pylori inocula exposed to water for different time periods (Fig. 3). Results show that H. pyloriwith 2 h and 6 h of water exposure retain the ability to induce IL-8 secretion similarlyto unexposed bacteria. However, after 24 h of exposure, H. pylori areno longer able to induce IL-8 production by AGS cells. Therefore, the case ofinflammation induced by the bacterium appears to be more related to the culturabilitystatus of H. pylori than to the ability of this microorganism to adhereto epithelial cells. In fact, although adhesion to host cells is immediately decreasedafter contact with water, after short time periods (up to 6 h), adhering H.pylori cells are still able to induce pro-inflammatory IL-8 secretion inthese cells.

Bottom Line: While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties.However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system.These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Pathology and Immunology, Medical Faculty, University of Porto, Porto, Portugal.

ABSTRACT
While the influence of water in Helicobacter pylori culturability and membrane integrity has been extensively studied, there are little data concerning the effect of this environment on virulence properties. Therefore, we studied the culturability of water-exposed H. pylori and determined whether there was any relation with the bacterium's ability to adhere, produce functional components of pathogenicity and induce inflammation and alterations in apoptosis in an experimental model of human gastric epithelial cells. H. pylori partially retained the ability to adhere to epithelial cells even after complete loss of culturability. However, the microorganism is no longer effective in eliciting in vitro host cell inflammation and apoptosis, possibly due to the non-functionality of the cag type IV secretion system. These H. pylori-induced host cell responses, which are lost along with culturability, are known to increase epithelial cell turnover and, consequently, could have a deleterious effect on the initial H. pylori colonisation process. The fact that adhesion is maintained by H. pylori to the detriment of other factors involved in later infection stages appears to point to a modulation of the physiology of the pathogen after water exposure and might provide the microorganism with the necessary means to, at least transiently, colonise the human stomach.

Show MeSH
Related in: MedlinePlus