ChePep Controls Helicobacter pylori Infection of the Gastric Glands and Chemotaxis in the Epsilonproteobacteria

ABSTRACTMicrobes use directed motility to colonize harsh and dynamic environments. We discovered thatHelicobacter pyloristrains establish bacterial colonies deep in the gastric glands and identified a novel protein, ChePep, necessary to colonize this niche. ChePep is preferentially localized to the flagellar pole. Although mutants lacking ChePep have normal flagellar ultrastructure and are motile, they have a slight defect in swarming ability. By tracking the movement of single bacteria, we found that ∆ChePep mutants cannot control the rotation of their flagella and swim with abnormally frequent reversals. These mutants even sustain bursts of movement backwards with the flagella pulling the bacteria. Genetic analysis of the chemotaxis signaling pathway shows that ChePep regulates flagellar rotation through the chemotaxis system. By examiningH. pyloriwithin a microscopic pH gradient, we determined that ChePep is critical for regulating chemotactic behavior. ThechePepgene is unique to theEpsilonproteobacteriabut is found throughout this diverse group. We expressed ChePep from other members of theEpsilonproteobacteria, including the zoonotic pathogenCampylobacter jejuniand the deep sea hydrothermal vent inhabitantCaminibacter mediatlanticus, inH. pyloriand found that ChePep is functionally conserved across this class. ChePep represents a new family of chemotaxis regulators unique to theEpsilonproteobacteriaand illustrates the different strategies that microbes have evolved to control motility.IMPORTANCEHelicobacter pyloristrains infect half of all humans worldwide and contribute to the development of peptic ulcers and gastric cancer.H. pyloricannot survive within the acidic lumen of the stomach and uses flagella to actively swim to and colonize the protective mucus and epithelium. The chemotaxis system allowsH. pylorito navigate by regulating the rotation of its flagella. We identified a new protein, ChePep, which controls chemotaxis inH. pylori. ChePep mutants fail to colonize the gastric glands of mice and are completely outcompeted by normalH. pylori. Genes encoding ChePep are found only in the classEpsilonproteobacteria, which includes the human pathogenCampylobacter jejuniand environmental microbes like the deep-sea hydrothermal vent colonizerCaminibacter mediatlanticus, and we show that ChePep function is conserved in this class. Our study identifies a new colonization factor inH. pyloriand also provides insight into the control and evolution of bacterial chemotaxis.

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A Gastric Pathogen Moves Chemotaxis in a New Direction

mBio ◽

10.1128/mbio.00201-11 ◽

2011 ◽

Vol 2 (5) ◽

Cited By ~ 1

Author(s):

Emily Goers Sweeney ◽

Karen Guillemin

Keyword(s):

Escherichia Coli ◽

Helicobacter Pylori ◽

Chemical Cues ◽

Swimming Behavior ◽

Human Pathogen ◽

Gastric Glands ◽

Content Type ◽

Gastric Pathogen ◽

H Pylori ◽

Novel Antibiotics

ABSTRACTFor almost 50 years,Escherichia colihas been the model for understanding how bacteria orient their movement in response to chemical cues, but recent studies of chemotaxis in other bacteria have revealed interesting variations from prevailing paradigms. Investigating the human pathogenHelicobacter pylori, Amieva and colleagues [mBio 2(4):e00098-11, 2011] discovered a new chemotaxis regulator, ChePep, which modulates swimming behavior through the canonical histidine-aspartate phosphorelay system. Functionally conserved among the epsilonproteobacteria, ChePep is essential forH. pylorito navigate deep into the stomach’s gastric glands and may be an attractive target for novel antibiotics.

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Galectin-3 Plays an Important Role in Innate Immunity to Gastric Infection by Helicobacter pylori

Infection and Immunity ◽

10.1128/iai.01299-15 ◽

2016 ◽

Vol 84 (4) ◽

pp. 1184-1193 ◽

Cited By ~ 35

Author(s):

Ah-Mee Park ◽

Satoru Hagiwara ◽

Daniel K. Hsu ◽

Fu-Tong Liu ◽

Osamu Yoshie

Keyword(s):

Innate Immunity ◽

Helicobacter Pylori ◽

Bacterial Cells ◽

Mucus Layer ◽

Iodide Uptake ◽

Gastric Glands ◽

Content Type ◽

Galectin 3 ◽

H Pylori ◽

Deficient Mice

We studied the role of galectin-3 (Gal3) in gastric infection byHelicobacter pylori. We first demonstrated that Gal3 was selectively expressed by gastric surface epithelial cells and abundantly secreted into the surface mucus layer. We next inoculatedH. pyloriSydney strain 1 into wild-type (WT) and Gal3-deficient mice using a stomach tube. At 2 weeks postinoculation, the bacterial cells were mostly trapped within the surface mucus layer in WT mice. In sharp contrast, they infiltrated deep into the gastric glands in Gal3-deficient mice. Bacterial loads in the gastric tissues were also much higher in Gal3-deficient mice than in WT mice. At 6 months postinoculation,H. pylorihad successfully colonized within the gastric glands of both WT and Gal3-deficient mice, although the bacterial loads were still higher in the latter. Furthermore, large lymphoid clusters mostly consisting of B cells were frequently observed in the gastric submucosa of Gal3-deficient mice.In vitro, peritoneal macrophages from Gal3-deficient mice were inefficient in killing engulfedH. pylori. Furthermore, recombinant Gal3 not only induced rapid aggregation ofH. pyloribut also exerted a potent bactericidal effect onH. pylorias revealed by propidium iodide uptake and a morphological shift from spiral to coccoid form. However, a minor fraction of bacterial cells, probably transient phase variants of Gal3-binding sugar moieties, escaped killing by Gal3. Collectively, our data demonstrate that Gal3 plays an important role in innate immunity to infection and colonization ofH. pylori.

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Divergent Mechanisms of Interaction of Helicobacter pylori and Campylobacter jejuni with Mucus and Mucins

Infection and Immunity ◽

10.1128/iai.00415-13 ◽

2013 ◽

Vol 81 (8) ◽

pp. 2838-2850 ◽

Cited By ~ 37

Author(s):

Julie Ann Naughton ◽

Karina Mariño ◽

Brendan Dolan ◽

Colm Reid ◽

Ronan Gough ◽

...

Keyword(s):

Helicobacter Pylori ◽

Campylobacter Jejuni ◽

Microarray Platform ◽

Parental Cell ◽

Content Type ◽

Intestinal Mucus ◽

Proximal Small Intestine ◽

Glycolipid Fraction ◽

H Pylori

ABSTRACTHelicobacter pyloriandCampylobacter jejunicolonize the stomach and intestinal mucus, respectively. Using a combination of mucus-secreting cells, purified mucins, and a novel mucin microarray platform, we examined the interactions of these two organisms with mucus and mucins.H. pyloriandC. jejunibound to distinctly different mucins.C. jejunidisplayed a striking tropism for chicken gastrointestinal mucins compared to mucins from other animals and preferentially bound mucins from specific avian intestinal sites (in order of descending preference: the large intestine, proximal small intestine, and cecum).H. pyloribound to a number of animal mucins, including porcine stomach mucin, but with less avidity than that ofC. jejunifor chicken mucin. The strengths of interaction of various wild-type strains ofH. pyloriwith different animal mucins were comparable, even though they did not all express the same adhesins. The production of mucus by HT29-MTX-E12 cells promoted higher levels of infection byC. jejuniandH. pylorithan those for the non-mucus-producing parental cell lines. BothC. jejuniandH. pyloribound to HT29-MTX-E12 mucus, and while both organisms bound to glycosylated epitopes in the glycolipid fraction of the mucus, onlyC. jejunibound to purified mucin. This study highlights the role of mucus in promoting bacterial infection and emphasizes the potential for even closely related bacteria to interact with mucus in different ways to establish successful infections.

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Dynamic Expression of the BabA Adhesin and Its BabB Paralog during Helicobacter pylori Infection in Rhesus Macaques

Infection and Immunity ◽

10.1128/iai.00094-17 ◽

2017 ◽

Vol 85 (6) ◽

Cited By ~ 13

Author(s):

Lori M. Hansen ◽

Pär Gideonsson ◽

Don R. Canfield ◽

Thomas Borén ◽

Jay V. Solnick

Keyword(s):

Helicobacter Pylori ◽

Gene Conversion ◽

Rhesus Macaques ◽

Phase Variation ◽

Asymptomatic Infection ◽

Blood Group Antigens ◽

Peptic Ulcers ◽

Content Type ◽

Fitness Advantage ◽

H Pylori

ABSTRACT Most Helicobacter pylori strains express the BabA adhesin, which binds to ABO/Leb blood group antigens on gastric mucin and epithelial cells and is found more commonly in strains that cause peptic ulcers or gastric cancer, rather than asymptomatic infection. We and others have previously reported that in mice, gerbils, and rhesus macaques, expression of babA is lost, either by phase variation or by gene conversion, in which the babB paralog recombines into the babA locus. The functional significance of loss of babA expression is unknown. Here we report that in rhesus monkeys, there is independent selective pressure for loss of babA and for overexpression of BabB, which confers a fitness advantage. Surprisingly, loss of babA by phase variation or gene conversion is not dependent on the capacity of BabA protein to bind Leb, which suggests that it may have other, unrecognized functions. These findings have implications for the role of outer membrane protein diversity in persistent H. pylori infection.

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Increased Production of Matrix Metalloproteinases in Helicobacter pylori Infection that Stimulates Gastric Cancer Stem Cells

International Journal of Veterinary Science ◽

10.37422/ijvs/20.043 ◽

2020 ◽

Keyword(s):

Gastric Cancer ◽

Stem Cells ◽

Helicobacter Pylori ◽

Cancer Stem Cells ◽

Histopathological Examination ◽

Physiological Saline ◽

Rrna Gene ◽

Peptic Ulcers ◽

Gastric Cancer Stem Cells ◽

H Pylori

Background and aim: Helicobacter pylori (H. pylori) is an incriminated pathogen causing diseases in both animals and humans and considered a zoonotic pathogen. H. pylori infection is considered a cause of gastric cancer, which rests a significant health care challenge. This study analyzes the expression pattern of matrix metalloprotein 2 (MMP-2) in patients with Helicobacter pylori-associated gastritis and the effect of H. pylori on gastric cancer stem cells, as well as study the role of helicon bacteriosis in dog in transmission of H. pylori infection to human. Materials and methods: Fifty-five of each sample (gastric biopsy, blood and stool) were collected from patients suffering from dyspepsia, chronic vomiting and perforated peptic ulcers and also from apparent healthy dogs. The investigation detected H. pylori by serological and histopathological examination. Biopsies were stored in physiological saline for identification of H. pylori by conventional time PCR. MMP-2 and Gastric cancer stem cells were then identified by immunohistochemistry. Results: Serological identification for H. pylori Antigen and Antibodies revealed (63% human, 50% dogs) and (87% human, 90% dogs) respectively were positive. Genotyping of H. pylori based on 16S rRNA gene showed 54.5% of human and 35% of dogs were positive. Immunohistochemistry revealed strong expression of CD44 in H. pylori- associated gastric cancer cases, MMP-2 expression was observed in all neoplastic lesions associated with H. pylori infection. Conclusion: H. pylori infection affects gastric mucosa and induces changes in gastric stem cells altering their differentiation and increased expression of MMP’s and CD44with a resultant potentiation of oncogenic alteration. In addition the up-regulation of both markers could be an instrumental to interpret the origination of gastric cancer.

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Agent-Based Modeling Demonstrates How Local Chemotactic Behavior Can Shape Biofilm Architecture

mSphere ◽

10.1128/msphere.00285-19 ◽

2019 ◽

Vol 4 (3) ◽

Cited By ~ 4

Author(s):

Emily G. Sweeney ◽

Andrew Nishida ◽

Alexandra Weston ◽

Maria S. Bañuelos ◽

Kristin Potter ◽

...

Keyword(s):

Helicobacter Pylori ◽

Three Dimensional ◽

Structural Features ◽

Agent Based Modeling ◽

Emergent Properties ◽

Cellular Interactions ◽

Biofilm Growth ◽

Content Type ◽

Agent Based ◽

H Pylori

ABSTRACTBacteria are often found living in aggregated multicellular communities known as biofilms. Biofilms are three-dimensional structures that confer distinct physical and biological properties to the collective of cells living within them. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms ofHelicobacter pylori, a common bacterial resident of human stomachs. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterizedH. pyloristrains with various AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis-defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger-scale emergent properties of biofilms.IMPORTANCEMost bacteria exist in aggregated, three-dimensional structures called biofilms. Although biofilms play important ecological roles in natural and engineered settings, they can also pose societal problems, for example, when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown thatHelicobacter pyloribacteria are repulsed by high concentrations of a self-produced molecule, AI-2, and thatH. pylorimutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here, we used computer simulations of biofilm formation to show that localH. pyloribehavior of repulsion from high AI-2 could explain the overall architecture ofH. pyloribiofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.

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A Novel Line Immunoassay Based on Recombinant Virulence Factors Enables Highly Specific and Sensitive Serologic Diagnosis of Helicobacter pylori Infection

Clinical and Vaccine Immunology ◽

10.1128/cvi.00433-13 ◽

2013 ◽

Vol 20 (11) ◽

pp. 1703-1710 ◽

Cited By ~ 26

Author(s):

Luca Formichella ◽

Laura Romberg ◽

Christian Bolz ◽

Michael Vieth ◽

Michael Geppert ◽

...

Keyword(s):

Helicobacter Pylori ◽

Immune Responses ◽

Virulence Factors ◽

Gastrointestinal Disease ◽

Individual Risk ◽

Enzyme Linked Immunosorbent Assay ◽

Type I ◽

Serologic Test ◽

Content Type ◽

H Pylori

ABSTRACTHelicobacter pyloricolonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome.H. pylorivirulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to importantH. pylorivirulence factors. This line immunoassay system (recomLine) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed inEscherichia coli, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) wereH. pylorinegative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), therecomLine assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, therecomLine assay provides a valuable tool for the diagnosis ofH. pyloriinfection.

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Basal Body Structures Differentially Affect Transcription of RpoN- and FliA-Dependent Flagellar Genes in Helicobacter pylori

Journal of Bacteriology ◽

10.1128/jb.02533-14 ◽

2015 ◽

Vol 197 (11) ◽

pp. 1921-1930 ◽

Cited By ~ 5

Author(s):

Jennifer Tsang ◽

Timothy R. Hoover

Keyword(s):

Helicobacter Pylori ◽

Basal Body ◽

Protein Interactions ◽

Transcript Levels ◽

Content Type ◽

Genes Encoding ◽

H Pylori ◽

Flagellar Biogenesis ◽

Flagellar Genes

ABSTRACTFlagellar biogenesis inHelicobacter pyloriis regulated by a transcriptional hierarchy governed by three sigma factors, RpoD (σ80), RpoN (σ54), and FliA (σ28), that temporally coordinates gene expression with the assembly of the flagellum. Previous studies showed that loss of flagellar protein export apparatus components inhibits transcription of flagellar genes. The FlgS/FlgR two-component system activates transcription of RpoN-dependent genes though an unknown mechanism. To understand better the extent to which flagellar gene regulation is coupled to flagellar assembly, we disrupted flagellar biogenesis at various points and determined how these mutations affected transcription of RpoN-dependent (flaBandflgE) and FliA-dependent (flaA) genes. The MS ring (encoded byfliF) is one of the earliest flagellar structures assembled. Deletion offliFresulted in the elimination of RpoN-dependent transcripts and an ∼4-fold decrease inflaAtranscript levels. FliH is a cytoplasmic protein that functions with the C ring protein FliN to shuttle substrates to the export apparatus. Deletions offliHand genes encoding C ring components (fliMandfliY) decreased transcript levels offlaBandflgEbut had little or no effect on transcript levels offlaA. Transcript levels offlaBandflgEwere elevated in mutants where genes encoding rod proteins (fliEandflgBC) were deleted, while transcript levels offlaAwas reduced ∼2-fold in both mutants. We propose that FlgS responds to an assembly checkpoint associated with the export apparatus and that FliH and one or more C ring component assist FlgS in engaging this flagellar structure.IMPORTANCEThe mechanisms used by bacteria to couple transcription of flagellar genes with assembly of the flagellum are poorly understood. The results from this study identified components of theH. pyloriflagellar basal body that either positively or negatively affect expression of RpoN-dependent flagellar genes. Some of these basal body proteins may interact directly with regulatory proteins that control transcription of theH. pyloriRpoN regulon, a hypothesis that can be tested by examining protein-protein interactionsin vitro.

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The Helicobacter pylori Autotransporter ImaA (HP0289) Modulates the Immune Response and Contributes to Host Colonization

Infection and Immunity ◽

10.1128/iai.00312-12 ◽

2012 ◽

Vol 80 (7) ◽

pp. 2286-2296 ◽

Cited By ~ 13

Author(s):

William E. Sause ◽

Andrea R. Castillo ◽

Karen M. Ottemann

Keyword(s):

Immune Response ◽

Helicobacter Pylori ◽

Membrane Protein ◽

Outer Membrane ◽

Outer Membrane Protein ◽

Dependent Manner ◽

Wild Type ◽

Content Type ◽

H Pylori ◽

Murine Infections

ABSTRACTThe human pathogenHelicobacter pyloriemploys a diverse collection of outer membrane proteins to colonize, persist, and drive disease within the acidic gastric environment. In this study, we sought to elucidate the function of the host-induced geneHP0289, which encodes an uncharacterized outer membrane protein. We first generated an isogenicH. pylorimutant that lacksHP0289and found that the mutant has a colonization defect in single-strain infections and is greatly outcompeted in mouse coinfection experiments with wild-typeH. pylori. Furthermore, we used protease assays and biochemical fractionation coupled with an HP0289-targeted peptide antibody to verify that the HP0289 protein resides in the outer membrane. Our previous findings showed that theHP0289promoter is upregulated in the mouse stomach, and here we demonstrate thatHP0289expression is induced under acidic conditions in an ArsRS-dependent manner. Finally, we have shown that theHP0289mutant induces greater expression of the chemokine interleukin-8 (IL-8) and the cytokine tumor necrosis factor alpha (TNF-α) in gastric carcinoma cells (AGS). Similarly, transcription of the IL-8 homolog keratinocyte-derived chemokine (KC) is elevated in murine infections with the HP0289 mutant than in murine infections with wild-typeH. pylori. On the basis of this phenotype, we renamed HP0289 ImaA forimmunomodulatoryautotransporter protein. Our work has revealed that genes inducedin vivoplay an important role inH. pyloripathogenesis. Specifically, the outer membrane protein ImaA modulates a component of the host inflammatory response, and thus may allowH. pylorito fine tune the host immune response based on ImaA expression.

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Systems Modeling of the Role of Interleukin-21 in the Maintenance of Effector CD4+ T Cell Responses during Chronic Helicobacter pylori Infection

mBio ◽

10.1128/mbio.01243-14 ◽

2014 ◽

Vol 5 (4) ◽

Cited By ~ 36

Author(s):

Adria Carbo ◽

Danyvid Olivares-Villagómez ◽

Raquel Hontecillas ◽

Josep Bassaganya-Riera ◽

Rupesh Chaturvedi ◽

...

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

T Cell ◽

Wild Type ◽

Content Type ◽

Interleukin 21 ◽

H Pylori ◽

Deficient Mice

ABSTRACTThe development of gastritis duringHelicobacter pyloriinfection is dependent on an activated adaptive immune response orchestrated by T helper (Th) cells. However, the relative contributions of the Th1 and Th17 subsets to gastritis and control of infection are still under investigation. To investigate the role of interleukin-21 (IL-21) in the gastric mucosa duringH. pyloriinfection, we combined mathematical modeling of CD4+T cell differentiation within vivomechanistic studies. We infected IL-21-deficient and wild-type mice withH. pyloristrain SS1 and assessed colonization, gastric inflammation, cellular infiltration, and cytokine profiles. ChronicallyH. pylori-infected IL-21-deficient mice had higherH. pyloricolonization, significantly less gastritis, and reduced expression of proinflammatory cytokines and chemokines compared to these parameters in infected wild-type littermates. Thesein vivodata were used to calibrate anH. pyloriinfection-dependent, CD4+T cell-specific computational model, which then described the mechanism by which IL-21 activates the production of interferon gamma (IFN-γ) and IL-17 during chronicH. pyloriinfection. The model predicted activated expression of T-bet and RORγt and the phosphorylation of STAT3 and STAT1 and suggested a potential role of IL-21 in the modulation of IL-10. Driven by our modeling-derived predictions, we found reduced levels of CD4+splenocyte-specifictbx21androrcexpression, reduced phosphorylation of STAT1 and STAT3, and an increase in CD4+T cell-specific IL-10 expression inH. pylori-infected IL-21-deficient mice. Our results indicate that IL-21 regulates Th1 and Th17 effector responses during chronicH. pyloriinfection in a STAT1- and STAT3-dependent manner, therefore playing a major role controllingH. pyloriinfection and gastritis.IMPORTANCEHelicobacter pyloriis the dominant member of the gastric microbiota in more than 50% of the world’s population.H. pyloricolonization has been implicated in gastritis and gastric cancer, as infection withH. pyloriis the single most common risk factor for gastric cancer. Current data suggest that, in addition to bacterial virulence factors, the magnitude and types of immune responses influence the outcome of colonization and chronic infection. This study uses a combined computational and experimental approach to investigate how IL-21, a proinflammatory T cell-derived cytokine, maintains the chronic proinflammatory T cell immune response driving chronic gastritis duringH. pyloriinfection. This research will also provide insight into a myriad of other infectious and immune disorders in which IL-21 is increasingly recognized to play a central role. The use of IL-21-related therapies may provide treatment options for individuals chronically colonized withH. pylorias an alternative to aggressive antibiotics.

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