Rapid evolution of the Helicobacter pylori AlpA adhesin in a high gastric cancer risk region from Colombia

To be able to survive, Helicobacter pylori must adhere to the gastric epithelial cells of its human host. For this purpose, the bacterium employs an array of adhesins, for example, AlpA. The adhesin AlpA has been proposed as a major adhesin because of its critical role in human stomach colonization. Therefore, understanding how AlpA evolved could be important for the development of new diagnostic strategies. However, the genetic variation and microevolutionary patterns of alpA have not been described in Colombia. The study aim was to describe the variation patterns and microevolutionary process of alpA in Colombian clinical isolates of H. pylori. The existing polymorphisms, which are deviations from the neutral model of molecular evolution, and the genetic differentiation of the alpA gene from Colombian clinical isolates of H. pylori were determined. The analysis shows that gene conversion and purifying selection have shaped the evolution of three different variants of alpA in Colombia.

Download Full-text

Phylogeographic Origin of Helicobacter pylori Determines Host-Adaptive Responses upon Coculture with Gastric Epithelial Cells

Infection and Immunity ◽

10.1128/iai.01182-12 ◽

2013 ◽

Vol 81 (7) ◽

pp. 2468-2477 ◽

Cited By ~ 16

Author(s):

Alexander Sheh ◽

Rupesh Chaturvedi ◽

D. Scott Merrell ◽

Pelayo Correa ◽

Keith T. Wilson ◽

...

Keyword(s):

Gene Expression ◽

Gastric Cancer ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Gastric Disease ◽

Gastric Epithelial Cells ◽

Gastric Cancer Risk ◽

Content Type ◽

H Pylori ◽

Induced Apoptosis

ABSTRACTWhileHelicobacter pyloriinfects over 50% of the world's population, the mechanisms involved in the development of gastric disease are not fully understood. Bacterial, host, and environmental factors play a role in disease outcome. To investigate the role of bacterial factors inH. pyloripathogenesis, global gene expression of sixH. pyloriisolates was analyzed during coculture with gastric epithelial cells. Clustering analysis of six Colombian clinical isolates from a region with low gastric cancer risk and a region with high gastric cancer risk segregated strains based on their phylogeographic origin. One hundred forty-six genes had increased expression in European strains, while 350 genes had increased expression in African strains. Differential expression was observed in genes associated with motility, pathogenicity, and other adaptations to the host environment. European strains had greater expression of the virulence factorscagA,vacA, andbabBand were associated with increased gastric histologic lesions in patients. In AGS cells, European strains promoted significantly higher interleukin-8 (IL-8) expression than did African strains. African strains significantly induced apoptosis, whereas only one European strain significantly induced apoptosis. Our data suggest that gene expression profiles of clinical isolates can discriminate strains by phylogeographic origin and that these profiles are associated with changes in expression of the proinflammatory and protumorigenic cytokine IL-8 and levels of apoptosis in host epithelial cells. These findings support the hypothesis that bacterial factors determined by the phylogeographic origin ofH. pyloristrains may promote increased gastric disease.

Download Full-text

Rabeprazole inhibits inflammatory reaction by inhibition of cell pyroptosis in gastric epithelial cells

BMC Pharmacology and Toxicology ◽

10.1186/s40360-021-00509-7 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Jing Xie ◽

Long Fan ◽

Liya Xiong ◽

Peiyu Chen ◽

Hongli Wang ◽

...

Keyword(s):

Epithelial Cells ◽

Clinical Sample ◽

Critical Role ◽

Enzyme Linked Immunosorbent Assay ◽

Inflammasome Activation ◽

Peptic Ulcers ◽

Gastric Epithelial Cells ◽

Caspase 1 ◽

H Pylori

Abstract Background Helicobacter pylori (H. pylori) is a common pathogen in development of peptic ulcers with pyroptosis. Rabeprazole, a critical component of standard triple therapy, has been widely used as the first-line regimen for H. pylori infectious treatment. The aim of this study to explore the function of Rabeprazole on cell pyroptosis in vitro. Methods The clinical sample from patients diagnosed with or without H. pylori-infection were collected to analyze by Immunohistochemistry (IHC). Real-time quantitative PCR (qPCR), western blot (WB) and enzyme linked immunosorbent assay (Elisa) were performed to analyze the effect of Rabeprazole on cell pyroptosis, including LDH, IL-1β and IL-18. Results In this study, we showed that Rabeprazole regulated a phenomenon of cell pyroptosis as confirmed by lactate dehydrogenase (LDH) assay. Further results showed that Rabeprazole inhibited cell pyroptosis in gastric epithelial cells by alleviating GSDMD-executed pyroptosis, leading to decrease IL-1β and IL-18 mature and secretion, which is attributed to NLRP3 inflammasome activation inhibition. Further analysis showed that ASC, NLRP3 and Caspase-1, was significantly repressed in response to Rabeprazole stimulation, resulting in decreasing cleaved-caspase-1 expression. Most important, NLRP3 and GSDMD is significantly increased in gastric tissue of patients with H. pylori infection. Conclusion These findings revealed a critical role of Rabeprazole in cell pyroptosis in patients with H. pylori infection, suggesting that targeting cell pyroptosis is an alternative strategy in improving H. pylori treatment.

Download Full-text

Serological Assays for Identification of Human Gastric Colonization by Helicobacter pylori Strains Expressing VacA m1 or m2

Clinical and Vaccine Immunology ◽

10.1128/cvi.00434-06 ◽

2007 ◽

Vol 14 (4) ◽

pp. 442-450 ◽

Cited By ~ 9

Author(s):

Chandrabali Ghose ◽

Guillermo I. Perez-Perez ◽

Victor J. Torres ◽

Marialuisa Crosatti ◽

Abraham Nomura ◽

...

Keyword(s):

Helicobacter Pylori ◽

Asian American ◽

Specific Antigen ◽

Secreted Protein ◽

Gastric Epithelial Cells ◽

Allele Specific ◽

Risk Of Disease ◽

Specific Antigens ◽

H Pylori ◽

Development Of Gastric Cancer

ABSTRACT The Helicobacter pylori vacA gene encodes a secreted protein (VacA) that alters the function of gastric epithelial cells and T lymphocytes. H. pylori strains containing particular vacA alleles are associated with differential risk of disease. Because the VacA midregion may exist as one of two major types, m1 or m2, serologic responses may potentially be used to differentiate between patients colonized with vacA m1- or vacA m2-positive H. pylori strains. In this study, we examined the utility of specific antigens from the m regions of VacA as allele-specific diagnostic antigens. We report that serological responses to P44M1, an H. pylori m1-specific antigen, are observed predominantly in patients colonized with m1-positive strains, whereas responses to VacA m2 antigens, P48M2 and P55M2, are observed in patients colonized with either m1- or m2-positive strains. In an Asian-American population, serologic responses to VacA m region-specific antigens were not able to predict the risk of development of gastric cancer.

Download Full-text

Effects ofHelicobacter pyloriand Heat Shock Protein 70 on the Proliferation of Human Gastric Epithelial Cells

Gastroenterology Research and Practice ◽

10.1155/2014/794342 ◽

2014 ◽

Vol 2014 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Liping Tao ◽

Hai Zou ◽

Zhimin Huang

Keyword(s):

Helicobacter Pylori ◽

Heat Shock ◽

Epithelial Cells ◽

Heat Shock Protein ◽

Mtt Assay ◽

Heat Shock Protein 70 ◽

Hsp70 Expression ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

H Pylori

Infection ofHelicobacter pylori (H. pylori)changed the proliferation of gastric epithelial cells and decreased the expression of heat shock protein 70 (HSP70). However, the effects ofH. pylorion the proliferation of gastric epithelial cells and the roles of HSP70 during the progress need further investigation.Objective.To investigate the effects ofHelicobacter pylori (H. pylori)and heat shock protein 70 (HSP70) on the proliferation of human gastric epithelial cells.Methods. H. pyloriand a human gastric epithelial cell line (AGS) were cocultured. The proliferation of AGS cells was quantitated by an MTT assay, and the expression of HSP70 in AGS cells was detected by Western blotting. HSP70 expression in AGS cells was silenced by small interfering RNA (siRNA) to investigate the role of HSP70. ThesiRNA-treated AGS cells were cocultured withH. pyloriand cell proliferation was measured by an MTT assay.Results.The proliferation of AGS cells was accelerated by coculturing withH. pylorifor 4 and 8 h, but was suppressed at 24 and 48 h. HSP70 expression was decreased in AGS cells infected byH. pylorifor 48 h. The proliferation in HSP70-silenced AGS cells was inhibited after coculturing withH. pylorifor 24 and 48 h compared with the control group.Conclusions.Coculture ofH. pylorialtered the proliferation of gastric epithelial cells and decreased HSP70 expression. HSP70 knockdown supplemented the inhibitory effect ofH. pylorion proliferation of epithelial cells. These results indicate that the effects ofH. pylorion the proliferation of gastric epithelial cells at least partially depend on the decreased expression of HSP70 induced by the bacterium.

Download Full-text

TIFA Signaling in Gastric Epithelial Cells Initiates the cag Type 4 Secretion System-Dependent Innate Immune Response to Helicobacter pylori Infection

mBio ◽

10.1128/mbio.01168-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 54

Author(s):

Alevtina Gall ◽

Ryan G. Gaudet ◽

Scott D. Gray-Owen ◽

Nina R. Salama

Keyword(s):

Immune Response ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Inflammatory Response ◽

Secretion System ◽

Innate Immune ◽

Gastric Ulcers ◽

Bacterial Clearance ◽

Gastric Epithelial Cells ◽

H Pylori

ABSTRACT Helicobacter pylori is a bacterial pathogen that colonizes the human stomach, causing inflammation which, in some cases, leads to gastric ulcers and cancer. The clinical outcome of infection depends on a complex interplay of bacterial, host genetic, and environmental factors. Although H. pylori is recognized by both the innate and adaptive immune systems, this rarely results in bacterial clearance. Gastric epithelial cells are the first line of defense against H. pylori and alert the immune system to bacterial presence. Cytosolic delivery of proinflammatory bacterial factors through the cag type 4 secretion system ( cag -T4SS) has long been appreciated as the major mechanism by which gastric epithelial cells detect H. pylori . Classically attributed to the peptidoglycan sensor NOD1, recent work has highlighted the role of NOD1-independent pathways in detecting H. pylori ; however, the bacterial and host factors involved have remained unknown. Here, we show that bacterially derived heptose-1,7-bisphosphate (HBP), a metabolic precursor in lipopolysaccharide (LPS) biosynthesis, is delivered to the host cytosol through the cag -T4SS, where it activates the host tumor necrosis factor receptor-associated factor (TRAF)-interacting protein with forkhead-associated domain (TIFA)-dependent cytosolic surveillance pathway. This response, which is independent of NOD1, drives robust NF-κB-dependent inflammation within hours of infection and precedes NOD1 activation. We also found that the CagA toxin contributes to the NF-κB-driven response subsequent to TIFA and NOD1 activation. Taken together, our results indicate that the sequential activation of TIFA, NOD1, and CagA delivery drives the initial inflammatory response in gastric epithelial cells, orchestrating the subsequent recruitment of immune cells and leading to chronic gastritis. IMPORTANCE H. pylori is a globally prevalent cause of gastric and duodenal ulcers and cancer. H. pylori antibiotic resistance is rapidly increasing, and a vaccine remains elusive. The earliest immune response to H. pylori is initiated by gastric epithelial cells and sets the stage for the subsequent immunopathogenesis. This study revealed that host TIFA and H. pylori -derived HBP are critical effectors of innate immune signaling that account for much of the inflammatory response to H. pylori in gastric epithelial cells. HBP is delivered to the host cell via the cag -T4SS at a time point that precedes activation of the previously described NOD1 and CagA inflammatory pathways. Manipulation of the TIFA-driven immune response in the host and/or targeting of ADP-heptose biosynthesis enzymes in H. pylori may therefore provide novel strategies that may be therapeutically harnessed to achieve bacterial clearance.

Download Full-text

Furazolidone- and Nitrofurantoin-ResistantHelicobacter pylori: Prevalence and Role of Genes Involved in Metronidazole Resistance

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.45.1.306-308.2001 ◽

2001 ◽

Vol 45 (1) ◽

pp. 306-308 ◽

Cited By ~ 43

Author(s):

Dong H. Kwon ◽

Miae Lee ◽

J. J. Kim ◽

J. G. Kim ◽

F. A. K. El-Zaatari ◽

...

Keyword(s):

Helicobacter Pylori ◽

Clinical Isolates ◽

Metronidazole Resistance ◽

H Pylori

ABSTRACT The prevalence of furazolidone, nitrofurantoin, and metronidazole resistance among Helicobacter pylori strains was assessed with 431 clinical isolates. Fifty-two percent were metronidazole resistant, compared to 2% (7 of 431) with resistance to furazolidone and nitrofurantoin. All seven furazolidone- and nitrofurantoin-resistant isolates were also metronidazole resistant.rdxA, frxA, and fdxB knockouts did not result in furazolidone or nitrofurantoin resistance. These data suggest that furazolidone and nitrofurantoin may be good alternatives to metronidazole for treating H. pylori infection.

Download Full-text

OX40L/OX40 Signal Promotes IL-9 Production by Mucosal MAIT Cells During Helicobacter pylori Infection

Frontiers in Immunology ◽

10.3389/fimmu.2021.626017 ◽

2021 ◽

Vol 12 ◽

Author(s):

Siqi Ming ◽

Mei Zhang ◽

Zibin Liang ◽

Chunna Li ◽

Jianzhong He ◽

...

Keyword(s):

Helicobacter Pylori ◽

Potential Role ◽

Critical Role ◽

Underlying Mechanism ◽

Mucosal Inflammation ◽

Cross Linking ◽

Mait Cells ◽

H Pylori ◽

Mait Cell

Mucosal associated invariant T (MAIT) cells play a critical role in Helicobacter pylori (H. pylori)-induced gastritis by promoting mucosal inflammation and aggravating mucosal injuries (1, 2). However, the underlying mechanism and key molecules involved are still uncertain. Here we identified OX40, a co-stimulatory molecule mainly expressed on T cells, as a critical regulator to promote proliferation and IL-9 production by MAIT cells and facilitate mucosal inflammation in H. pylori-positive gastritis patients. Serum examination revealed an increased level of IL-9 in gastritis patients. Meanwhile, OX40 expression was increased in mucosal MAIT cells, and its ligand OX40L was also up-regulated in mucosal dendritic cells (DCs) of gastritis patients, compared with healthy controls. Further results demonstrated that activation of the OX40/OX40L pathway promoted IL-9 production by MAIT cells, and MAIT cells displayed a highly-activated phenotype after the cross-linking of OX40 and OX40L. Moreover, the level of IL-9 produced by MAIT cells was positively correlated with inflammatory indexes in the gastric mucosa, suggesting the potential role of IL-9-producing MAIT cells in mucosal inflammation. Taken together, we elucidated that OX40/OX40L axis promoted mucosal MAIT cell proliferation and IL-9 production in H. pylori-induced gastritis, which may provide potential targeting strategies for gastritis treatment.

Download Full-text

Helicobacter pylori Induces Gastric Epithelial Cell Apoptosis in Association with Increased Fas Receptor Expression

Infection and Immunity ◽

10.1128/iai.67.8.4237-4242.1999 ◽

1999 ◽

Vol 67 (8) ◽

pp. 4237-4242 ◽

Cited By ~ 106

Author(s):

Nicola L. Jones ◽

Andrew S. Day ◽

Hilary A. Jennings ◽

Philip M. Sherman

Keyword(s):

Cell Death ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Receptor Expression ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

Fas Receptor ◽

Epithelial Cell Apoptosis ◽

H Pylori

ABSTRACT The mechanisms involved in mediating the enhanced gastric epithelial cell apoptosis observed during infection withHelicobacter pylori in vivo are unknown. To determine whether H. pylori directly induces apoptosis of gastric epithelial cells in vitro and to define the role of the Fas-Fas ligand signal transduction cascade, human gastric epithelial cells were infected with H. pylori for up to 72 h under microaerophilic conditions. As assessed by both transmission electron microscopy and fluorescence microscopy, incubation with acagA-positive, cagE-positive, VacA-positive clinical H. pylori isolate stimulated an increase in apoptosis compared to the apoptosis of untreated AGS cells (16.0% ± 2.8% versus 5.9% ± 1.4%, P < 0.05) after 72 h. In contrast, apoptosis was not detected following infection withcagA-negative, cagE-negative, VacA-negative clinical isolates or a Campylobacter jejuni strain. In addition to stimulating apoptosis, infection with H. pylorienhanced Fas receptor expression in AGS cells to a degree comparable to that of treatment with a positive control, gamma interferon (12.5 ng/ml) (148% ± 24% and 167% ± 24% of control, respectively). The enhanced Fas receptor expression was associated with increased sensitivity to Fas-mediated cell death. Ligation of the Fas receptor with an agonistic monoclonal antibody resulted in an increase in apoptosis compared to the apoptosis of cells infected with the bacterium alone (38.5% ± 7.1% versus 16.0% ± 2.8%,P < 0.05). Incubation with neutralizing anti-Fas antibody did not prevent apoptosis of H. pylori-infected cells. Taken together, these findings demonstrate that the gastric pathogen H. pylori stimulates apoptosis of gastric epithelial cells in vitro in association with the enhanced expression of the Fas receptor. These data indicate a role for Fas-mediated signaling in the programmed cell death that occurs in response toH. pylori infection.

Download Full-text

Lactobacillus fermentum UCO-979C beneficially modulates the innate immune response triggered by Helicobacter pylori infection in vitro

Beneficial Microbes ◽

10.3920/bm2018.0019 ◽

2018 ◽

Vol 9 (5) ◽

pp. 829-841 ◽

Cited By ~ 7

Author(s):

V. Garcia-Castillo ◽

H. Zelaya ◽

A. Ilabaca ◽

M. Espinoza-Monje ◽

R. Komatsu ◽

...

Keyword(s):

Immune Response ◽

Helicobacter Pylori ◽

Epithelial Cells ◽

Morphological Changes ◽

Helicobacter Pylori Infection ◽

Lactobacillus Fermentum ◽

Gastric Tissue ◽

Gastric Epithelial Cells ◽

Ags Cells ◽

H Pylori

Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.

Download Full-text

Helicobacter pylori induces intracellular galectin-8 aggregation around damaged lysosomes within gastric epithelial cells in a host O-glycan-dependent manner

Glycobiology ◽

10.1093/glycob/cwy095 ◽

2018 ◽

Vol 29 (2) ◽

pp. 151-162 ◽

Cited By ~ 6

Author(s):

Fang-Yen Li ◽

I-Chun Weng ◽

Chun-Hung Lin ◽

Mou-Chieh Kao ◽

Ming-Shiang Wu ◽

...

Keyword(s):

Helicobacter Pylori ◽

Epithelial Cells ◽

Rhesus Macaques ◽

Dependent Manner ◽

Gastric Epithelial Cells ◽

Vacuolating Cytotoxin ◽

Infected Cells ◽

H Pylori ◽

Autophagy Activity ◽

Binding Lectin

Abstract Galectin-8, a beta-galactoside-binding lectin, is upregulated in the gastric tissues of rhesus macaques infected with Helicobacter pylori. In this study, we found that H. pylori infection triggers intracellular galectin-8 aggregation in human-derived AGS gastric epithelial cells, and that these aggregates colocalize with lysosomes. Notably, this aggregation is markedly reduced following the attenuation of host O-glycan processing. This indicates that H. pylori infection induces lysosomal damage, which in turn results in the accumulation of cytosolic galectin-8 around damaged lysosomes through the recognition of exposed vacuolar host O-glycans. H. pylori-induced galectin-8 aggregates also colocalize with autophagosomes, and galectin-8 ablation reduces the activation of autophagy by H. pylori. This suggests that galectin-8 aggregates may enhance autophagy activity in infected cells. We also observed that both autophagy and NDP52, an autophagy adapter, contribute to the augmentation of galectin-8 aggregation by H. pylori. Additionally, vacuolating cytotoxin A, a secreted H. pylori cytotoxin, may contribute to the increased galectin-8 aggregation and elevated autophagy response in infected cells. Collectively, these results suggest that H. pylori promotes intracellular galectin-8 aggregation, and that galectin-8 aggregation and autophagy may reciprocally regulate each other during infection.

Download Full-text