The Neutrophil-Activating Protein (Hp-Nap) of Helicobacter pylori Is a Protective Antigen and a Major Virulence Factor

Helicobacter pylori infection induces the appearance of inflammatory infiltrates, consisting mainly of neutrophils and monocytes, in the human gastric mucosa. A bacterial protein with neutrophil activating activity (HP-NAP) has been previously identified, but its role in infection and immune response is still largely unknown. Here, we show that vaccination of mice with HP-NAP induces protection against H. pylori challenge, and that the majority of infected patients produce antibodies specific for HP-NAP, suggesting an important role of this factor in immunity. We also show that HP-NAP is chemotactic for human leukocytes and that it activates their NADPH oxidase to produce reactive oxygen intermediates, as demonstrated by the translocation of its cytosolic subunits to the plasma membrane, and by the lack of activity on chronic granulomatous disease leukocytes. This stimulating effect is strongly potentiated by tumor necrosis factor α and interferon γ and is mediated by a rapid increase of the cytosolic calcium concentration. The activation of leukocytes induced by HP-NAP is completely inhibited by pertussis toxin, wortmannin, and PP1. On the basis of these results, we conclude that HP-NAP is a virulence factor important for the H. pylori pathogenic effects at the site of infection and a candidate antigen for vaccine development.

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Peroral immunization with Helicobacter pylori adhesin protein genetically linked to cholera toxin A2B subunits

Clinical Science ◽

10.1042/cs1000291 ◽

2001 ◽

Vol 100 (3) ◽

pp. 291-298 ◽

Cited By ~ 7

Author(s):

Byung Oh KIM ◽

Sung Seup SHIN ◽

Young Hyo YOO ◽

Suhkneung PYO

Keyword(s):

Helicobacter Pylori ◽

Cholera Toxin ◽

Vaccine Development ◽

Protective Antigen ◽

Oral Immunization ◽

Size Exclusion ◽

Vaccine Antigen ◽

Igg Antibodies ◽

Serum Igg ◽

H Pylori

Helicobacter pylori is a major cause of gastric-associated diseases. To evaluate the efficacy of a possible vaccine antigen against H. pylori infection, the chimaeric construct adhesin–CTXA2B, derived from H. pylori adhesin genetically coupled to cholera toxin (CTX) subunits A2 and B (CTXA2B), was expressed in Escherichia coli as an insoluble recombinant chimaeric protein. The protein was then purified by denaturation, renaturation and size-exclusion chromatography. The composition of purified adhesin–CTXA2B was verified by SDS/PAGE and Western blotting with antibodies to antigenic components of adhesin and CTXB, and confirmed as a chimaeric protein with GM1-ganglioside binding activity and adhesin epitopes by a GM1-ELISA developed using antibodies to adhesin. Oral immunization of mice with adhesin–CTXA2B induced higher levels of mucosal IgA and serum IgG antibodies to H. pylori adhesin and to CTXB than in mice immunized with adhesin or CTXA2B alone. Adhesin–CTXA2B was also demonstrated to be a potential protective antigen in a mouse model of H. pylori infection. The immunization of mice with adhesin–CTXA2B protected 62.5% of mice infected with H. pylori SS1 strain, whereas adhesin immunization was not able to confer protection to mice. This protection may be correlated with high levels of mucosal IgA and serum IgG antibodies against H. pylori adhesin. Taken together, the results indicate that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin–CTXA2B chimaeric protein could be a potential component in future H. pylori vaccine development.

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A multi-method and structure-based in silico vaccine designing against Helicobacter pylori employing immuno-informatics approach

Current Proteomics ◽

10.2174/1570164617999200414120231 ◽

2020 ◽

Vol 17 ◽

Author(s):

Anam Naz ◽

Tahreem Zaheer ◽

Hamza Arshad Dar ◽

Faryal Mehwish Awan ◽

Ayesha Obaid ◽

...

Keyword(s):

Helicobacter Pylori ◽

Vaccine Development ◽

Amino Acid Sequences ◽

The Body ◽

New Drugs ◽

Toll Like Receptor ◽

Peptide Vaccines ◽

Hla Alleles ◽

Vaccine Candidates ◽

H Pylori

Background: Helicobacter pylori infection and its treatment still remains a challenge to human health worldwide. A variety of antibiotics and combination therapies are currently used to treat H. pylori induced ulcers and carcinoma; however, no effective treatment is available to eliminate the pathogen from the body. Additionally, antibiotic resistance is also one of the main reasons for prolonged and persistent infection. Aim of the study: Until new drugs are available for this infection, vaccinology seems the only alternative opportunity to exploit against H. pylori induced diseases. Methods: Multiple epitopes prioritized in our previous study have been tested for their possible antigenic combinations, and results in 169-mer and 183-mer peptide vaccines containing the amino acid sequences of 3 and 4 epitopes respectively, along with adjuvant (Cholera Toxin Subunit B adjuvant at 5’ end) and linkers (GPGPG and EAAAK). Results: Poly-epitope proteins proposed as potential vaccine candidates against H. pylori include SabAHP0289-Omp16-VacA (SHOV), VacA-Omp16-HP0289-FecA (VOHF), VacA-Omp16-HP0289-SabA (VOHS), VacA-Omp16-HP0289-BabA (VOHB), VacA-Omp16-HP0289-SabA-FecA (VOHSF), VacAOmp16-HP0289-SabA-BabA (VOHSB) and VacA-Omp16-HP0289-BabA-SabA (VOHBS). Structures of these poly-epitope peptide vaccines have been modelled and checked for their affinity with HLA alleles and receptors. These proposed poly-epitope vaccine candidates bind efficiently with A2, A3, B7 and DR1 superfamilies of HLA alleles. They can also form stable and significant interactions with Toll-like receptor 2 and Toll-like receptor 4. Conclusion: Results suggest that these multi-epitopic vaccines can elicit a significant immune response against H. pylori and can be tested further for efficient vaccine development.

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Role of TNF-α-Inducing Protein Secreted by Helicobacter pylori as a Tumor Promoter in Gastric Cancer and Emerging Preventive Strategies

Toxins ◽

10.3390/toxins13030181 ◽

2021 ◽

Vol 13 (3) ◽

pp. 181

Author(s):

Masami Suganuma ◽

Tatsuro Watanabe ◽

Eisaburo Sueoka ◽

In Kyoung Lim ◽

Hirota Fujiki

Keyword(s):

Gastric Cancer ◽

Helicobacter Pylori ◽

Cell Surface Receptor ◽

Tumor Promoter ◽

Cancer Development ◽

Human Gastric Cancer ◽

Tnf Α ◽

Surface Receptor ◽

H Pylori ◽

Factor Α

The tumor necrosis factor-α (TNF-α)-inducing protein (tipα) gene family, comprising Helicobacter pylori membrane protein 1 (hp-mp1) and tipα, has been identified as a tumor promoter, contributing to H. pylori carcinogenicity. Tipα is a unique H. pylori protein with no similarity to other pathogenicity factors, CagA, VacA, and urease. American H. pylori strains cause human gastric cancer, whereas African strains cause gastritis. The presence of Tipα in American and Euro-Asian strains suggests its involvement in human gastric cancer development. Tipα secreted from H. pylori stimulates gastric cancer development by inducing TNF-α, an endogenous tumor promoter, through its interaction with nucleolin, a Tipα receptor. This review covers the following topics: tumor-promoting activity of the Tipα family members HP-MP1 and Tipα, the mechanism underlying this activity of Tipα via binding to the cell-surface receptor, nucleolin, the crystal structure of rdel-Tipα and N-terminal truncated rTipα, inhibition of Tipα-associated gastric carcinogenesis by tumor suppressor B-cell translocation gene 2 (BTG2/TIS21), and new strategies to prevent and treat gastric cancer. Thus, Tipα contributes to the carcinogenicity of H. pylori by a mechanism that differs from those of CagA and VacA.

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Molecular Characterization of a Flagellar Export Locus of Helicobacter pylori

Infection and Immunity ◽

10.1128/iai.67.5.2060-2070.1999 ◽

1999 ◽

Vol 67 (5) ◽

pp. 2060-2070 ◽

Cited By ~ 31

Author(s):

Steffen Porwollik ◽

Brian Noonan ◽

Paul W. O’Toole

Keyword(s):

Helicobacter Pylori ◽

Virulence Factor ◽

Housekeeping Genes ◽

Reading Frame ◽

Reverse Transcription Pcr ◽

Mutant Strains ◽

H Pylori ◽

Export Protein ◽

Successful Colonization

ABSTRACT Motility of Helicobacter species has been shown to be essential for successful colonization of the host. We have investigated the organization of a flagellar export locus in Helicobacter pylori. A 7-kb fragment of the H. pylori CCUG 17874 genome was cloned and sequenced, revealing an operon comprising an open reading frame of unknown function (ORF03), essential housekeeping genes (ileS and murB), flagellar export genes (fliI and fliQ), and a homolog to a gene implicated in virulence factor transport in other pathogens (virB11). A promoter for this operon, showing similarity to the Escherichia coli ς70 consensus, was identified by primer extension. Cotranscription of the genes in the operon was demonstrated by reverse transcription-PCR, and transcription of virB11, fliI, fliQ, andmurB was detected in human or mouse biopsies obtained from infected hosts. The genetic organization of this locus was conserved in a panel of H. pylori clinical isolates. EngineeredfliI and fliQ mutant strains were completely aflagellate and nonmotile, whereas a virB11 mutant still produced flagella. The fliI and fliQ mutant strains produced reduced levels of flagellin and the hook protein FlgE. Production of OMP4, a member of the outer membrane protein family identified in H. pylori 26695, was reduced in both thevirB11 mutant and the fliI mutant, suggesting related functions of the virulence factor export protein (VirB11) and the flagellar export component (FliI).

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Helicobacter pylori (H. pylori) infection increases IL-8 and IL-6 production from human gastric mucosa

Gastroenterology ◽

10.1016/0016-5085(95)27387-5 ◽

1995 ◽

Vol 108 (4) ◽

pp. A769

Author(s):

T. Ando ◽

K. Kusugami ◽

M. Sakakibara ◽

T. Shimizu ◽

M. Shinoda ◽

...

Keyword(s):

Helicobacter Pylori ◽

Gastric Mucosa ◽

Human Gastric Mucosa ◽

H Pylori

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γ-Glutamyltransferase Is a Helicobacter pylori Virulence Factor but Is Not Essential for Colonization

Infection and Immunity ◽

10.1128/iai.69.6.4168-4173.2001 ◽

2001 ◽

Vol 69 (6) ◽

pp. 4168-4173 ◽

Cited By ~ 68

Author(s):

K. J. McGovern ◽

T. G. Blanchard ◽

J. A. Gutierrez ◽

S. J. Czinn ◽

S. Krakowka ◽

...

Keyword(s):

Helicobacter Pylori ◽

Virulence Factor ◽

Bacterial Load ◽

H Pylori ◽

Glutamyl Transpeptidase ◽

Isogenic Strains

ABSTRACT The contribution of glutamyl transpeptidase (GGT) (γ-glutamyltransferase [EC 2. 3. 2. 2]) to Helicobacter pylori virulence was investigated in piglets and mice using GGT-deficient isogenic strains. All animals became colonized. However, the bacterial load was significantly lower for mutant bacteria than for parent strains. These results suggest that GGT activity provides an advantage to H. pylori in colonization.

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Therapeutic Vaccination against Helicobacter pylori in the Beagle Dog Experimental Model: Safety, Immunogenicity, and Efficacy

Infection and Immunity ◽

10.1128/iai.72.6.3252-3259.2004 ◽

2004 ◽

Vol 72 (6) ◽

pp. 3252-3259 ◽

Cited By ~ 65

Author(s):

Giacomo Rossi ◽

Paolo Ruggiero ◽

Samuele Peppoloni ◽

Laura Pancotto ◽

Damiano Fortuna ◽

...

Keyword(s):

Helicobacter Pylori ◽

Bacterial Colonization ◽

Human Infection ◽

Human Gastric Mucosa ◽

Therapeutic Vaccination ◽

Beagle Dogs ◽

Beagle Dog ◽

Vaccine Approach ◽

H Pylori ◽

Different Doses

ABSTRACT Helicobacter pylori is a gram-negative bacterium that colonizes the human gastric mucosa causing gastritis and peptic ulcer and increasing the risk of gastric cancer. The efficacy of current antibiotic-based therapies can be limited by problems of patient compliance and increasing antibiotic resistance; the vaccine approach can overcome these limits. The present study describes the therapeutic vaccination of experimentally H. pylori-infected beagle dogs, an animal model that reproduces several aspects of the human infection with H. pylori. The vaccine consisted of three recombinant H. pylori antigens, CagA, VacA, and NAP, formulated at different doses (10, 25, or 50 μg each) with alum and administered intramuscularly either weekly or monthly. No adverse effects were observed after vaccination and a good immunoglobulin G response was generated against each of the three antigens. Bacterial colonization and gastritis were decreased after the completion of the vaccination cycle, especially in the case of the monthly immunization schedule. In conclusion, therapeutic vaccination in the beagle dog model was safe and immunogenic and was able to limit H. pylori colonization and the related gastric pathology.

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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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Effect of FliK mutation on the transcriptional activity of the σ 54 sigma factor RpoN in Helicobacter pylori

Microbiology ◽

10.1099/mic.0.026062-0 ◽

2009 ◽

Vol 155 (6) ◽

pp. 1901-1911 ◽

Cited By ~ 7

Author(s):

Francois P. Douillard ◽

Kieran A. Ryan ◽

Jason Hinds ◽

Paul W. O'Toole

Keyword(s):

Helicobacter Pylori ◽

Sigma Factor ◽

Transcriptional Activity ◽

Human Gastric Mucosa ◽

Hook Length ◽

Altered Expression ◽

Flagellar Assembly ◽

Gene Regulatory ◽

H Pylori ◽

And Control

Helicobacter pylori is a motile Gram-negative bacterium that colonizes and persists in the human gastric mucosa. The flagellum gene regulatory circuitry of H. pylori is unique in many aspects compared with the Salmonella/Escherichia coli paradigms, and some regulatory checkpoints remain unclear. FliK controls the hook length during flagellar assembly. Microarray analysis of a fliK-null mutant revealed increased transcription of genes under the control of the σ 54 sigma factor RpoN. This sigma factor has been shown to be responsible for transcription of the class II flagellar genes, including flgE and flaB. No genes higher in the flagellar hierarchy had altered expression, suggesting specific and localized FliK-dependent feedback on the RpoN regulon. FliK thus appears to be involved in three processes: hook-length control, export substrate specificity and control of RpoN transcriptional activity.

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Induction of various cytokines and development of severe mucosal inflammation by cagA gene positive Helicobacter pylori strains

Gut ◽

10.1136/gut.41.4.442 ◽

1997 ◽

Vol 41 (4) ◽

pp. 442-451 ◽

Cited By ~ 240

Author(s):

Y Yamaoka ◽

M Kita ◽

T Kodama ◽

N Sawai ◽

K Kashima ◽

...

Keyword(s):

Helicobacter Pylori ◽

Expression Patterns ◽

Mucosal Inflammation ◽

Enzyme Linked Immunosorbent Assay ◽

Biopsy Specimens ◽

Tnf Α ◽

Polymerase Chain ◽

H Pylori ◽

Factor Α ◽

Necrosis Factor

Background—Helicobacter pyloristrains possessing the cagA gene are thought to induce interleukin 8 (IL-8) in gastric mucosa. However, it is still unclear whether a relation exists between the cagA gene and the expression patterns of cytokines other than IL-8.Aims—To investigate the relation between the cagA gene and the production of various cytokine proteins using an enzyme linked immunosorbent assay (ELISA).Patients and methods—In 184 patients, the cagA gene was detected by polymerase chain reaction (PCR), and levels of production of IL-1β, IL-6, IL-7, IL-8, IL-10, and tumour necrosis factor α (TNF-α) in antral biopsy specimens were measured by ELISA.Results—Mucosal levels of IL-1β, IL-6, IL-8, and TNF-α were significantly higher in H pyloripositive than in H pylori negative patients. Furthermore, the mucosal levels of IL-1β and IL-8 were significantly higher in specimens infected with cagApositive strains than in those infected with cagAnegative strains. In H pylori positive patients, the mucosal level of IL-8 was closely correlated with that of IL-1β (p<0.0001), and the mucosal level of IL-6 was closely correlated with that of TNF-α (p<0.0001).Conclusion—These findings suggest that the ability to induce cytokines differs among the strains;cagA+ strains induce various kinds of cytokines and may cause severe inflammation, whereascagA− strains induce IL-8 and IL-1β only weakly and may cause only mild inflammation. However, as most patients infected with the cagA+ strains have gastritis, these strains may not be equivalent to ulcerogenic strains.

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