Novel Functions for Glycosyltransferases Jhp0562 and GalT in Lewis Antigen Synthesis and Variation in Helicobacter pylori

ABSTRACTLewis (Le) antigens are fucosylated oligosaccharides present in theHelicobacter pylorilipopolysaccharide. Expression of these antigens is believed to be important forH. pyloricolonization, since Le antigens also are expressed on the gastric epithelia in humans. A galactosyltransferase encoded by β-(1,3)galTis essential for production of type 1 (Leaand Leb) antigens. The upstream genejhp0562, which is present in many but not allH. pyloristrains, is homologous to β-(1,3)galTbut is of unknown function. BecauseH. pyloridemonstrates extensive intragenomic recombination, we hypothesized that these two genes could undergo DNA rearrangement. A PCR screen and subsequent sequence analyses revealed that the two genes can recombine at both the 5′ and 3′ ends. Chimeric β-(1,3)galT-like alleles can restore function in a β-(1,3)galTnull mutant, but neither native nor recombinantjhp0562can. Mutagenesis ofjhp0562revealed that it is essential for synthesis of both type 1 and type 2 Le antigens. Transcriptional analyses of both loci showed β-(1,3)galTexpression in all wild-type (WT) and mutant strains tested, whereasjhp0562was not expressed injhp0562null mutants, as expected. Sincejhp0562unexpectedly displayed functions in both type 1 and type 2 Le synthesis, we asked whethergalT, part of the type 2 synthesis pathway, had analogous functions in type 1 synthesis. Mutagenesis and complementation analysis confirmed thatgalTis essential for Lebproduction. In total, these results demonstrate thatgalTandjhp0562have functions that cross the expected Le synthesis pathways and thatjhp0562provides a substrate for intragenomic recombination to generate diverse Le synthesis enzymes.

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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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The Helicobacter pylori Autotransporter ImaA Tempers the Bacterium's Interaction with α5β1 Integrin

Infection and Immunity ◽

10.1128/iai.00450-16 ◽

2016 ◽

Vol 85 (1) ◽

Cited By ~ 5

Author(s):

William E. Sause ◽

Daniela Keilberg ◽

Soufiane Aboulhouda ◽

Karen M. Ottemann

Keyword(s):

Helicobacter Pylori ◽

Host Cell ◽

Type Iv Secretion ◽

Host Cells ◽

Wild Type ◽

Content Type ◽

Type Iv ◽

H Pylori ◽

Α5β1 Integrin ◽

Cell Interface

ABSTRACT The human pathogen Helicobacter pylori uses the host receptor α5β1 integrin to trigger inflammation in host cells via its cag pathogenicity island (cag PAI) type IV secretion system (T4SS). Here, we report that the H. pylori ImaA protein (HP0289) decreases the action of the cag PAI T4SS via tempering the bacterium's interaction with α5β1 integrin. Previously, imaA-null mutants were found to induce an elevated inflammatory response that was dependent on the cag PAI T4SS; here we extend those findings to show that the elevated response is independent of the CagA effector protein. To understand how ImaA could be affecting cag PAI T4SS activity at the host cell interface, we utilized the Phyre structural threading program and found that ImaA has a region with remote homology to bacterial integrin-binding proteins. This region was required for ImaA function. Unexpectedly, we observed that imaA mutants bound higher levels of α5β1 integrin than wild-type H. pylori, an outcome that required the predicted integrin-binding homology region of ImaA. Lastly, we report that ImaA directly affected the amount of host cell β1 integrin but not other cellular integrins. Our results thus suggest a model in which H. pylori employs ImaA to regulate interactions between integrin and the T4SS and thus alter the host inflammatory strength.

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The Entner-Doudoroff Pathway Has Little Effect on Helicobacter pylori Colonization of Mice

Infection and Immunity ◽

10.1128/iai.71.5.2920-2923.2003 ◽

2003 ◽

Vol 71 (5) ◽

pp. 2920-2923 ◽

Cited By ~ 10

Author(s):

Amy E. Wanken ◽

Tyrrell Conway ◽

Kathryn A. Eaton

Keyword(s):

Helicobacter Pylori ◽

Wild Type ◽

Mutant Strains ◽

H Pylori ◽

Type Strains

ABSTRACT Helicobacter pylori mutants deficient in 6-phosphogluconate dehydratase (6PGD) were constructed. Colonization densities were lower and minimum infectious doses were higher for mutant strains than for wild-type strains. In spite of better colonization, however, wild-type strains did not displace the mutant in cocolonization experiments. Loss of 6PGD diminishes the fitness of H. pylori in vivo, but the pathway is nonessential for colonization.

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Helicobacter pylori–binding nonacid glycosphingolipids in the human stomach

Journal of Biological Chemistry ◽

10.1074/jbc.ra118.004854 ◽

2018 ◽

Vol 293 (44) ◽

pp. 17248-17266 ◽

Cited By ~ 6

Author(s):

Chunsheng Jin ◽

Angela Barone ◽

Thomas Borén ◽

Susann Teneberg

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Structural Complexity ◽

Human Stomach ◽

Carbohydrate Binding ◽

Human Gastric Mucosa ◽

H Pylori ◽

Contrast Information

Helicobacter pylori has a number of well-characterized carbohydrate-binding adhesins (BabA, SabA, and LabA) that promote adhesion to the gastric mucosa. In contrast, information on the glycoconjugates present in the human stomach remains unavailable. Here, we used MS and binding of carbohydrate-recognizing ligands to characterize the glycosphingolipids of three human stomachs from individuals with different blood group phenotypes (O(Rh−)P, A(Rh+)P, and A(Rh+)p), focusing on compounds recognized by H. pylori. We observed a high degree of structural complexity, and the composition of glycosphingolipids differed among individuals with different blood groups. The type 2 chain was the dominating core chain of the complex glycosphingolipids in the human stomach, in contrast to the complex glycosphingolipids in the human small intestine, which have mainly a type 1 core. H. pylori did not bind to the O(Rh−)P stomach glycosphingolipids, whose major complex glycosphingolipids were neolactotetraosylceramide, the Lex, Lea, and H type 2 pentaosylceramides, and the Ley hexaosylceramide. Several H. pylori-binding compounds were present among the A(Rh+)P and A(Rh+)p stomach glycosphingolipids. Ligands for BabA-mediated binding of H. pylori were the Leb hexaosylceramide, the H type 1 pentaosylceramide, and the A type 1/ALeb heptaosylceramide. Additional H. pylori-binding glycosphingolipids recognized by BabA-deficient strains were lactosylceramide, lactotetraosylceramide, the x2 pentaosylceramide, and neolactohexaosylceramide. Our characterization of human gastric receptors required for H. pylori adhesion provides a basis for the development of specific compounds that inhibit the binding of this bacterium to the human gastric mucosa.

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Localized Suppression of Inflammation at Sites of Helicobacter pylori Colonization

Infection and Immunity ◽

10.1128/iai.05602-11 ◽

2011 ◽

Vol 79 (10) ◽

pp. 4186-4192 ◽

Cited By ~ 16

Author(s):

Alison L. Every ◽

Garrett Z. Ng ◽

Caroline D. Skene ◽

Stacey N. Harbour ◽

Anna K. Walduck ◽

...

Keyword(s):

Helicobacter Pylori ◽

Potential Model ◽

Gastric Ph ◽

Male Mice ◽

Wild Type ◽

Content Type ◽

Female Mice ◽

Gastric Corpus ◽

Acid Secreting ◽

H Pylori

ABSTRACTWhile gastric adenocarcinoma is the most serious consequence ofHelicobacter pyloriinfection, not all infected persons develop this pathology. Individuals most at risk of this cancer are those in whom the bacteria colonize the acid-secreting region of the stomach and subsequently develop severe inflammation in the gastric corpus. It has been reported anecdotally that male mice become infected with greater numbers ofH. pyloribacteria than female mice. While investigating this phenomenon, we found that increasedH. pyloriinfection densities in male mice were not related to antibody production, and this phenomenon was not normalized by gonadectomy. However, the gastric pH in male 129/Sv mice was significantly elevated compared with that in female mice. Differences in colonization were evident within 1 day postinfection and significantly arose due to colonization of the gastric corpus region in male mice. This provided a potential model for comparing the effect of corpus colonization on the development of gastritis. This was explored using two models ofH. pylori-induced inflammation, namely, 2-month infections ofMuc1−/−mice and 6-month infections of wild-type 129/Sv mice. WhileH. pyloriinfection of female mice induced a severe, corpus-predominant atrophic gastritis, to our surprise, male mice developed minimal inflammation despite being colonized with significantly moreH. pyloribacteria than female controls. Thus, colonization of the gastric corpus in male mice was associated with a loss of inflammation in that region. The suppression of inflammation concomitant with infection of the gastric corpus in male mice demonstrates a powerful localized suppression of inflammation induced at sites ofH. pyloricolonization.

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Effect of Glycine on Helicobacter pylori In Vitro

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.48.10.3782-3788.2004 ◽

2004 ◽

Vol 48 (10) ◽

pp. 3782-3788 ◽

Cited By ~ 15

Author(s):

Masaaki Minami ◽

Takafumi Ando ◽

Shin-nosuke Hashikawa ◽

Keizo Torii ◽

Tadao Hasegawa ◽

...

Keyword(s):

Helicobacter Pylori ◽

Eradication Therapy ◽

Resistant Mutant ◽

Synergistic Activity ◽

Wild Type ◽

Mutant Strains ◽

The Difference ◽

H Pylori ◽

Isogenic Mutants

ABSTRACT Glycine is the simplest amino acid and is used as a metabolic product in some bacteria. However, an excess of glycine inhibits the growth of many bacteria, and it is used as a nonspecific antiseptic agent due to its low level of toxicity in animals. The effect of glycine on Helicobacter pylori is not precisely known. The present study was conducted to investigate (i) the effect of glycine on clarithromycin (CLR)-resistant and -susceptible strains of H. pylori, (ii) the effect of glycine in combination with amoxicillin (AMX), and (iii) the postantibiotic effect (PAE). The MIC at which 90% of strains are inhibited for glycine was almost 2.5 mg/ml for 31 strains of H. pylori, including CLR-resistant strains. We constructed isogenic CLR-resistant mutant strains by natural transformation and investigated the difference between clinical wild-type strains and isogenic mutants. There were no differences in the MICs between CLR-resistant and -susceptible strains or between clinical wild-type and mutant strains. The combination of AMX and glycine showed synergistic activity, with the minimum bactericidal concentration of AMX with glycine decreasing to 1/10 that of AMX alone. Glycine showed no PAE against H. pylori. These results suggest that glycine may be a useful antimicrobial agent against H. pylori not only alone but also in combination with antibacterial drugs for the treatment of H. pylori-associated diseases. Glycine may represent a component of a new type of eradication therapy for CLR-resistant H. pylori.

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Contribution of Secretory Antibodies to Intestinal Mucosal Immunity against Helicobacter pylori

Infection and Immunity ◽

10.1128/iai.01424-12 ◽

2013 ◽

Vol 81 (10) ◽

pp. 3880-3893 ◽

Cited By ~ 17

Author(s):

Rebecca J. Gorrell ◽

Odilia L. C. Wijburg ◽

John S. Pedersen ◽

Anna K. Walduck ◽

Terry Kwok ◽

...

Keyword(s):

Helicobacter Pylori ◽

Antibody Response ◽

Bacterial Load ◽

Secretory Iga ◽

Mouse Strains ◽

Wild Type ◽

Content Type ◽

Immunoglobulin Receptor ◽

H Pylori ◽

Secretory Antibodies

ABSTRACTThe natural immune response toHelicobacter pylorineither clears infection nor prevents reinfection. However, the ability of secretory antibodies to influence the course ofH. pyloriinfection has not been determined. We compared the natural progression ofH. pyloriinfection in wild-type C57BL/6 mice with that in mice lacking the polymeric immunoglobulin receptor (pIgR) that is essential for the secretion of polymeric antibody across mucosal surfaces.H. pyloriSS1-infected wild-type and pIgR knockout (KO) mice were sampled longitudinally for gastrointestinal bacterial load, antibody response, and histological changes. The gastric bacterial loads of wild-type and pIgR KO mice remained constant and comparable at up to 3 months postinfection (mpi) despite SS1-reactive secretory IgA in the intestinal contents of wild-type mice at that time. Conversely, abundant duodenal colonization of pIgR KO animals contrasted with the near-total eradication ofH. pylorifrom the intestine of wild-type animals by 3 mpi.H. pyloriwas cultured only from the duodenum of those animals in which colonization in the distal gastric antrum was of sufficient density for immunohistological detection. By 6 mpi, the gastric load ofH. pyloriin wild-type mice was significantly lower than in pIgR KO animals. While there was no corresponding difference between the two mouse strains in gastric pathology results at 6 mpi, reductions in gastric bacterial load correlated with increased gastric inflammation together with an intestinal secretory antibody response in wild-type mice. Together, these results suggest that naturally produced secretory antibodies can modulate the progress ofH. pyloriinfection, particularly in the duodenum.

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Helicobacter pylori Stores Nickel To Aid Its Host Colonization

Infection and Immunity ◽

10.1128/iai.00858-12 ◽

2012 ◽

Vol 81 (2) ◽

pp. 580-584 ◽

Cited By ~ 21

Author(s):

Stéphane L. Benoit ◽

Erica F. Miller ◽

Robert J. Maier

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Physiological Role ◽

Wild Type ◽

Rank Tests ◽

Content Type ◽

Host Mouse ◽

H Pylori ◽

Very High

ABSTRACTThe transition metal nickel (Ni) is critical for the pathogenicity ofHelicobacter pylori. Indeed the element is a required component of two enzymes, hydrogenase and urease, that have been shown to be important forin vivocolonization of the host gastric mucosa. Urease accounts for up to 10% of the total cellularH. pyloriprotein content, and therefore the bacterial Ni demand is very high.H. pyloripossess two small and abundant histidine-rich, Ni-binding proteins, Hpn and Hpn-like, whose physiological role in the host have not been investigated. In this study, special husbandry conditions were used to control Ni levels in the host (mouse), including the use of Ni-free versus Ni-supplemented food. The efficacy of each diet was confirmed by measuring the Ni concentrations in sera of mice fed with either diet. Colonization levels (based on rank tests) of theΔhpn Δhpn-like double mutants isolated from the mice provided Ni-deficient chow were statistically lower than those for mice given Ni in their diet. In contrast,H. pyloriwild-type colonization levels were similar in both host groups (e.g., regardless of Ni levels). Our results indicate that the gastric pathogenH. pylorican utilize stored Ni via defined histidine-rich proteins to aid colonization of the host.

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Study of the Association Between Diabetes and Helicobacter Pylori Infection in a Tunisian Population

European Journal of Medical and Health Sciences ◽

10.24018/ejmed.2020.2.4.423 ◽

2020 ◽

Vol 2 (4) ◽

Author(s):

Chaima Jemai ◽

Rim Rachdi ◽

Sonia Bellamine ◽

Lamia Bouallegue ◽

Faika Ben Mami

Keyword(s):

Helicobacter Pylori ◽

Medical Records ◽

Tunisian Population ◽

Control Group ◽

Patients With Diabetes ◽

And Gender ◽

H Pylori ◽

Control Study

Introduction: The association between diabetes and Helicobacter Pylori (H. Pylori) infection remains controversial in the literature. The aim of our study was to search an association between diabetes and H. Pylori infection. Methods: This is a case-control study carried out in 2017 over 3 months (September-October-November), collecting 120 patients with dyspepsia, matched for age and gender into two groups: a group of 77 patients with diabetes, and a group of control cases made of 43 non-diabetics. Diabetes was defined according to the American Diabetes Association (ADA) of 2017. Clinical, biological, endoscopic and anatomopathological data were collected from medical records. Results: The average age of the patients was 50±2,1 year. The sex ratio was 0.51. 34.2% (n=41) patients were male. Diabetes was type 2 in the majority of cases (88.31%) and type 1 in 11.68% only. H. Pylori infection was more prevalent in diabetics (19.48%, 11.63%, p=0.27). H. Pylori infection was more prevalent in type 1 diabetics (44.44%, 16.18%, p= 0.04). The frequency of upper endoscopic lesions in diabetics and controls was 70.13% and 74.42%, respectively. Chronic gastritis, gastric atrophy, and intestinal metaplasia were found in 61%, 3.9% and 2.6% of the cases in the group of diabetics and 62.79%, 6.98% and 4.65% respectively in the control group (p= not significant (NS)). Conclusion: Our study shows the absence of a significant association between diabetes and H. Pylori infection, as well as the absence of endoscopic and histological specificities of this infection in patients with diabetes.

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