1
|
Effects of Anti-Helicobacter pylori Therapy on Incidence of Autoimmune Diseases, Including Inflammatory Bowel Diseases. Clin Gastroenterol Hepatol 2019; 17:1991-1999. [PMID: 30580094 PMCID: PMC9629375 DOI: 10.1016/j.cgh.2018.12.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 11/30/2018] [Accepted: 12/14/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Helicobacter pylori induces immune tolerance and is associated with a lower risk for immune-mediated disorders, such as autoimmune and inflammatory bowel diseases (IBD). We aimed to determine the effects of treatment for H pylori infection on the incidence of autoimmune disease and IBD. METHODS We collected data from the National Health Insurance Research Database in Taiwan on patients younger than 18 years old without a prior diagnosis of autoimmune disease or IBD. Patients with peptic ulcer disease (PUD) with treatment of H pylori infection (PUD+HPRx), PUD without H pylori treatment (PUD-HPRx), a urinary tract infection (UTI) treated with cephalosporin, or without PUD (controls) were matched for age, sex, insurance, and Charlson's comorbidity index score. RESULTS Of the 1 million patients we collected data from in 2005, we included 79,181 patients in the study. We compared the effects of treatment for H pylori infection on the risk of autoimmunity or IBD and found that PUD+HPRx has the highest adjusted hazard risk (aHR) for autoimmunity or IBD (aHR, 2.36), compared to PUD-HPRx (aHR, 1.91) or UTI (aHRs, 1.71) (P < .001). The increased risk of autoimmune disease was not completely accounted for by antibiotic therapy alone, because PUD+HPRx had a higher aHR than UTI (P < .001). A small but significant increase in mortality was observed in the PUD+HPRx cohort (aHR, 1.11; P = .001). CONCLUSION In an analysis of data from the National Health Insurance Research Database in Taiwan, we found that treatment for H pylori infection is associated with a significant increase in the risk for autoimmune disease, including IBD.
Collapse
|
2
|
Capitani N, Codolo G, Vallese F, Minervini G, Grassi A, Cianchi F, Troilo A, Fischer W, Zanotti G, Baldari CT, de Bernard M, D'Elios MM. The lipoprotein HP1454 of Helicobacter pylori regulates T-cell response by shaping T-cell receptor signalling. Cell Microbiol 2019; 21:e13006. [PMID: 30646431 DOI: 10.1111/cmi.13006] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 11/22/2018] [Accepted: 11/29/2018] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori (HP) is a Gram-negative bacterium that chronically infects the stomach of more than 50% of human population and represents a major cause of gastric cancer, gastric lymphoma, gastric autoimmunity, and peptic ulcer. It still remains to be elucidated, which HP virulence factors are important in the development of gastric disorders. Here, we analysed the role of the HP protein HP1454 in the host-pathogen interaction. We found that a significant proportion of T cells isolated from HP patients with chronic gastritis and gastric adenocarcinoma proliferated in response to HP1454. Moreover, we demonstrated in vivo that HP1454 protein drives Th1/Th17 inflammatory responses. We further analysed the in vitro response of human T cells exposed either to an HP wild-type strain or to a strain with a deletion of the hp1454 gene, and we revealed that HP1454 triggers the T-cell antigen receptor-dependent signalling and lymphocyte proliferation, as well as the CXCL12-dependent cell adhesion and migration. Our study findings prove that HP1454 is a crucial bacterial factor that exerts its proinflammatory activity by directly modulating the T-cell response. The relevance of these results can be appreciated by considering that compelling evidence suggest that chronic gastric inflammation, a condition that paves the way to HP-associated diseases, is dependent on T cells.
Collapse
Affiliation(s)
- Nagaja Capitani
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.,Department of Life Sciences, University of Siena, Siena, Italy
| | - Gaia Codolo
- Department of Biology, University of Padua, Padua, Italy
| | - Francesca Vallese
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Alessia Grassi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Fabio Cianchi
- Department of Surgery, University of Florence, Florence, Italy
| | - Arianna Troilo
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Wolfgang Fischer
- Max von Pettenkofer-Institutfür Hygiene und Medizinische Mikrobiologie, Ludwig Maximilian University of Munich, Munich, Germany
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | | | - Mario M D'Elios
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| |
Collapse
|
3
|
Helicobacter pylori-induced autoimmune thyroiditis: is the pathogenic link concluded or still a hypothesis? ACTA ACUST UNITED AC 2018. [DOI: 10.1097/mrm.0000000000000133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
4
|
Cheng XJ, Lin JC, Tu SP. Etiology and Prevention of Gastric Cancer. Gastrointest Tumors 2016; 3:25-36. [PMID: 27722154 PMCID: PMC5040890 DOI: 10.1159/000443995] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Gastric cancer is a heterogeneous malignant disease associated with environmental and genetic predisposing factors. While gastric cancer incidence and mortality fell greatly globally over the past decades, it remains the fourth cause of cancer-related death worldwide. Thus, prevention of gastric cancer is still a major strategy for improvement of gastric cancer prognosis. SUMMARY Helicobacter pylori infection has been demonstrated to be a major risk factor for the development of gastric cancer. Unhealthy diet and lifestyle, including high-salt food, smoking and drinking, are able to induce genotypic and phenotypic transformation of gastric epithelial cells. Gene mutations (such as E-cadherin) in stomach epithelial cells are major genetic causes for gastric cancer. The eradication of H. pylori has been demonstrated to be an effective approach for primary prevention of gastric cancer. Increased intake of a diet rich in vegetables and fresh fruits as well as smoking cessation have been shown to reduce the incidence of gastric cancer. The secondary prevention strategy is to screen premalignant gastric lesions by endoscopy. Biomarker tests are also reliable methods to identify gastric precancerous lesions. Endoscopy screening is still the gold standard for diagnosis of gastric cancer. KEY MESSAGE H. pylori infection, a diet rich in salted and/or smoked food and red meat, as well as gene mutations are major risk factors for the development of gastric cancer. PRACTICAL IMPLICATIONS The eradication of H. pylori is a major primary preventive strategy of gastric cancer. A healthy lifestyle, including increased intake of a diet rich in fruit and vegetables, reduced intake of salted and smoked food and red meat, a reduction of alcohol intake as well as smoking cessation will be effective approaches for the prevention of gastric cancer.
Collapse
Affiliation(s)
| | | | - Shui Ping Tu
- Department of Oncology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| |
Collapse
|
5
|
Suzuki H, Mori H. Different Pathophysiology of Gastritis between East and West? An Asian Perspective. Inflamm Intest Dis 2016; 1:123-128. [PMID: 29922667 DOI: 10.1159/000446301] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Accepted: 04/13/2016] [Indexed: 12/20/2022] Open
Abstract
Background The incidence of gastric cancer in Asia is higher than that in Europe and Northern America. Helicobacter pylori infection is the most important factor for the development of atrophic gastritis and gastric cancer. The geographical distribution of the prevalence and virulence factors of H. pylori are important to understand the difference between gastritis in the East and West. Summary Articles comparing gastritis cases between eastern and western countries showed that the severity of gastritis is closely related to the risk of gastric cancer, and the severity of gastritis is more advanced in East Asia. Although the prevalence of H. pylori infection is closely associated with the incidence of gastric cancer in European countries, the severity of gastritis and the high incidence of gastric cancer in East Asia are not dependent only on the prevalence of H. pylori infection itself. From the viewpoint of the virulence factors of H. pylori, the East Asian CagA-positive strain (EPIYA motif ABD type) is peculiar in East Asia. Considering comprehensively the geographical distribution of H. pylori subtypes is the most important factor among all prospected risk factors for the incidence of gastric cancer and the rate of development of gastritis. While eating habits, such as salty foods, vegetables and fruits, might influence the progression of gastritis, such factors might be responsible for the geographic heterogeneity of gastritis. Key Message East Asian CagA-positive H. pylori is the strongest risk factor for gastric carcinogenesis and the development of gastritis.
Collapse
Affiliation(s)
- Hidekazu Suzuki
- Medical Education Center, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
| | - Hideki Mori
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
6
|
The Gastric Mucosa from Patients Infected with CagA+ or VacA+ Helicobacter pylori Has a Lower Level of Dual Oxidase-2 Expression than Uninfected or Infected with CagA-/VacA- H. pylori. Dig Dis Sci 2016; 61:2328-2337. [PMID: 27048452 PMCID: PMC4943970 DOI: 10.1007/s10620-016-4144-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 03/22/2016] [Indexed: 02/08/2023]
Abstract
BACKGROUND Helicobacter pylori (H. pylori) is a well-recognized gastroduodenal pathogen and class I carcinogen. Dual oxidase-2 (DUOX2), a member of NADPH oxidase family, has several critical physiological functions, including thyroid hormone biosynthesis and host mucosal defense. AIM To investigate the effect of H. pylori infection on DUOX2 gene expression in human stomach. MATERIALS AND METHODS The biopsies were obtained from patients who underwent endoscopic diagnosis. The patient serum was assayed for two virulence factors of H. pylori, CagA IgG and VacA. The inflammation in gastric mucosa was analyzed with histology. Real-time quantitative PCR was used to detect the expression of three members of NADPH oxidase, NOX1, NOX2, and DUOX2, as well as lactoperoxidase (LPO) in the gastric mucosa. NOX2, DUOX2, and myeloperoxidase (MPO) protein levels were quantified by Western blots or immunohistochemistry. RESULTS The H. pylori-infected gastric mucosa had more severe inflammation than uninfected samples. However, the expression of DUOX2 mRNA and protein was lower in gastric mucosa of patients with H. pylori infection compared to the uninfected. Among the H. pylori-infected patients, those having CagA IgG or VacA in the serum had lower DUOX2 expression levels than those infected with H. pylori without either virulence factor. The NOX2 and MPO levels were higher in those patients infected with H. pylori irrespective of the virulence factors than those uninfected patients. NOX1 and LPO mRNA were undetectable in the gastric mucosa. CONCLUSION CagA+ or VacA+ H. pylori in the stomach of patients may suppress DUOX2 expression to promote its own survival. Increased NOX2 could not eliminate H. pylori infection.
Collapse
|
7
|
Rokkas T, Gisbert JP, Niv Y, O'Morain C. The association between Helicobacter pylori infection and inflammatory bowel disease based on meta-analysis. United European Gastroenterol J 2015; 3:539-50. [PMID: 26668747 DOI: 10.1177/2050640615580889] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND In humans there are epidemiological data suggesting a protective effect of Helicobacter pylori (H. pylori) infection against the development of autoimmune diseases and in addition, there are laboratory data illustrating H. pylori's ability to induce immune tolerance and limit inflammatory responses. Thus, numerous observational studies have examined the association between H. pylori infection and inflammatory bowel disease (IBD) with various results. OBJECTIVE We performed a meta-analysis of available studies to better define the association of H. pylori infection and IBD. METHODS Medical literature searches for human studies were performed through September 2014, using suitable keywords. In each study the risk ratio (RR) of H. pylori infection in IBD patients vs controls was calculated and pooled estimates were obtained using fixed- or random-effects models as appropriate. Heterogeneity between studies was evaluated using Cochran Q test and I(2) statistics, whereas the likelihood of publication bias was assessed by constructing funnel plots. RESULTS Thirty-three studies were eligible for meta-analysis, including 4400 IBD patients and 4763 controls. Overall 26.5% of IBD patients were positive for H. pylori infection, compared to 44.7% of individuals in the control group. There was significant heterogeneity in the included studies (Q = 137.2, df (Q) =32, I(2) ( )= 77%, p < 0.001) and therefore the random-effects model of meta-analysis was used. The obtained pool RR estimation was 0.62 (95% confidence interval (CI) 0.55-0.71, test for overall effect Z = -7.04, p < 0.001). There was no evidence of publication bias. CONCLUSION The results of this meta-analysis showed a significant negative association between H. pylori infection and IBD that supports a possible protective benefit of H. pylori infection against the development of IBD.
Collapse
Affiliation(s)
- T Rokkas
- Gastroenterology Clinic, Henry Dunant Hospital Center, Athens, Greece
| | - J P Gisbert
- Gastroenterology Unit, La Princesa University Hospital, Instituto de Investigación Sanitaria Princesa (IIS-IP), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Madrid, Spain
| | - Y Niv
- Department of Gastroenterology, Rabin Medical Center, Tel Aviv University, Tel Aviv, Israel
| | - C O'Morain
- Department of Gastroenterology, Meath/Adelaide Hospital, Dublin, Ireland
| |
Collapse
|
8
|
ASTL J, ŠTERZL I. Activation of Helicobacter Pylori Causes Either Autoimmune Thyroid Diseases or Carcinogenesis in the Digestive Tract. Physiol Res 2015; 64:S291-301. [DOI: 10.33549/physiolres.933118] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori has been implicated in stimulation of immune system, development of autoimmune endocrinopathies as autoimmune thyroiditis (AT) and on other hand induction of immunosupresion activates gastric and extra-gastric diseases such as gastric ulcer or cancer. It causes persistent lifelong infection despite local and systemic immune response. Our results indicate that Helicobacter pylori might cause inhibition of the specific cellular immune response in Helicobacter pylori-infected patients with or without autoimmune diseases such as AT. We cannot also declare the carcinogenic effect in oropharynx. However the association of any infection agents and cancerogenesis exists. The adherence of Helicobacter pylori expression and enlargement of benign lymphatic tissue and the high incidence of the DNA of Helicobacter pylori in laryngopharyngeal and oropharyngeal cancer is reality. LTT appears to be a good tool for detection of immune memory cellular response in patients with Helicobacter pylori infection and AT. All these complications of Helicobacter pylori infection can be abrogated by successful eradication of Helicobacter pylori.
Collapse
Affiliation(s)
| | - I. ŠTERZL
- Department of Immunoendocrinology, Institute of Endocrinology, Prague, Czech Republic
| |
Collapse
|
9
|
Histological variety of gastric carcinoma and Helicobacter pylori cagA and vacA polymorphism. Eur J Gastroenterol Hepatol 2015; 27:1017-21. [PMID: 26067222 DOI: 10.1097/meg.0000000000000414] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Helicobacter pylori infection may increase the risk of both histotypes of gastric carcinoma (GC): intestinal (IGC) and diffuse (DGC). Polymorphism of the main H. pylori virulence factors, cagA and vacA, could have a different impact on the histological variety of GC. METHODS Two hundred and twenty-six H. pylori colonies were examined from 28 GC patients: 15 with IGC and 13 with DGC. DNA was extracted from bacteria and a PCR was performed using primers specific for cagA, the 3' cagA variable region and s and m regions of vacA. RESULTS There were 214 cagA+ strains and 55.61% of them were isolated from IGC cases; there were 12 cagA- colonies and they were all isolated from DGC (P<0.001). Most patients were infected by strains with more than one cagA structural type. No strains with a particular cagA type were found to be significantly more frequent in either histological variety of GC. A percentage of 43.90 of strains with vacA subtype s1/m1 were isolated from IGC, whereas 80.95% of vacA subtype s1/m2 strains were isolated from DGC cases (P<0.001). CONCLUSION Polymorphism of the main virulence genes of H. pylori may play different roles in the pathogenesis of IGC and DGC.
Collapse
|
10
|
Kim SH, Sierra RA, McGee DJ, Zabaleta J. Transcriptional profiling of gastric epithelial cells infected with wild type or arginase-deficient Helicobacter pylori. BMC Microbiol 2012; 12:175. [PMID: 22889111 PMCID: PMC3438056 DOI: 10.1186/1471-2180-12-175] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 07/18/2012] [Indexed: 12/23/2022] Open
Abstract
Background Helicobacter pylori causes acute and chronic gastric inflammation induced by proinflammatory cytokines and chemokines secreted by cells of the gastric mucosa, including gastric epithelial cells. Previous studies have demonstrated that the bacterial arginase, RocF, is involved in inhibiting T cell proliferation and CD3ζ expression, suggesting that arginase could be involved in a more general dampening of the immune response, perhaps by down-regulation of certain pro-inflammatory mediators. Results Global transcriptome analysis was performed on AGS gastric epithelial cells infected for 16 hours with a wild type Helicobacter pylori strain 26695, an arginase mutant (rocF-) or a rocF+ complemented strain. H. pylori infection triggered altered host gene expression in genes involved in cell movement, death/growth/proliferation, and cellular function and maintenance. While the wild type strain stimulates host inflammatory pathways, the rocF- mutant induced significantly more expression of IL-8. The results of the microarray were verified using real-time PCR, and the differential levels of protein expression were confirmed by ELISA and Bioplex analysis. MIP-1B was also significantly secreted by AGS cells after H. pylori rocF- mutant infection, as determined by Bioplex. Even though not explored in this manuscript, the impact that the results presented here may have on the development of gastritis, warrant further research to understand the underlying mechanisms of the relationship between H. pylori RocF and IL-8 induction. Conclusions We conclude that H. pylori arginase modulates multiple host signaling and metabolic pathways of infected gastric epithelial cells. Arginase may play a critical role in anti-inflammatory host responses that could contribute to the ability of H. pylori to establish chronic infections.
Collapse
Affiliation(s)
- Songhee H Kim
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA
| | | | | | | |
Collapse
|
11
|
Diverse H. pylori strains, IL-10 promoter polymorphisms with high morbidity of gastric cancer in Hexi area of Gansu Province, China. Mol Cell Biochem 2011; 362:241-8. [PMID: 22081333 DOI: 10.1007/s11010-011-1149-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 11/03/2011] [Indexed: 01/05/2023]
Abstract
In Hexi area of Gansu Province, people have a higher susceptibility of gastric cancer than people in the rest area of China. There is substantial geographic variation in the incidence of gastric cancer. In this article, the present author explored the roles of H. pylori infection and IL-10 promoter polymorphisms in development of gastric cancer in this area. A total of 304 participants were admitted to our study, and they were divided into two groups: control group and case group. Blood samples from all subjects were collected for gene extraction using DNA extraction kits. IL-10 polymorphisms were determined by SNaPshot Multiplex. To test H. pylori infection and its typing H. pylori antibody Immunoblotting Kits were used. This research suggested that environmental factor played an important role in the pathogenesis of gastric carcinoma in the area, H. pylori infection increased the risk of gastric cancer (OR = 2.612, 95% CI 1.636-4.170) and subject with H. pylori I-type positive was at significantly higher risk for progression to gastric cancer (OR = 4.712, 95% CI 2.656-8.537). For subjects with the ATA/GCC or GCC/GCC haplotype of the IL-10-1082/-819/-592 polymorphism relative to the ATA/ATA haplotype group, the risk of gastric cancer development was significantly increased. It has been demonstrated that the presence of IL-10-819 C alleles and IL-10-592 C alleles was associated with an increased risk for gastric cancer development in H. pylori-infected patients and IL-10 promoter polymorphisms and H. pylori have a synergistic effect on gastric cancer in Hexi population.
Collapse
|
12
|
Ayala G, Flores-Luna L, Hernández-Amaro D, Mendoza-Hernández G, Chihu-Amparán L, Bernal-Sahagún F, Camorlinga M, Lazcano-Ponce E, Torres J. Association of circulating VacA-neutralizing antibodies with gastric cancer and duodenal ulcer. Cancer Causes Control 2011; 22:1425-34. [PMID: 21779758 DOI: 10.1007/s10552-011-9817-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 07/05/2011] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To study the association between anti-VacA antibodies and pre-neoplastic lesions (IM), gastric cancer (GC), and duodenal ulcer (DU). METHODS A case-control study that included 347 patients, 90 with IM, 60 with GC, 52 with DU, and 145 with non-atrophic gastritis was conducted. For the analysis, a polytomous logistic regression models were used. Anti-VacA antibodies were identified in sera from these patients, either by Western blot assay (WB), using antigens produced by H. pylori s1m1 strain, or by neutralization assay challenging HeLa cells with H. pylori VacA s1m1 cytotoxin. RESULTS Results of the WB assay showed no association between WB-anti-VacA antibodies and gastroduodenal diseases. In contrast, when antibodies that neutralize VacA cytotoxic activity were studied, a significant association was found with IM (OR 2.7, 95% CI 1.4-5.1) and DU (OR 2.3, 95% CI 1.1-4.9) and an even stronger association with GC (OR 3.9, 95% CI 1.8-8.5). A significant association with histological subtypes of GC (diffuse and intestinal) and of IM (complete and incomplete) was also found. In addition, the association showed a significant dose-response effect in the case of GC, but not of DU or IM. These associations did not change substantially after adjustment for confounding factors. MAIN CONCLUSION This study showed that VacA-neutralizing antibodies are significantly associated with gastroduodenal diseases, especially GC, and that they might be used as risk markers of GC and DU.
Collapse
Affiliation(s)
- Guadalupe Ayala
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Universidad No. 655, entre Cerrada Los Pinos y Caminera. Col. Santa María Ahuacatitlán, CP 62100, Cuernavaca, Morelos, Mexico.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Vermoote M, Vandekerckhove TTM, Flahou B, Pasmans F, Smet A, De Groote D, Van Criekinge W, Ducatelle R, Haesebrouck F. Genome sequence of Helicobacter suis supports its role in gastric pathology. Vet Res 2011; 42:51. [PMID: 21414191 PMCID: PMC3065412 DOI: 10.1186/1297-9716-42-51] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2010] [Accepted: 03/17/2011] [Indexed: 01/14/2023] Open
Abstract
Helicobacter (H.) suis has been associated with chronic gastritis and ulcers of the pars oesophagea in pigs, and with gastritis, peptic ulcer disease and gastric mucosa-associated lymphoid tissue lymphoma in humans. In order to obtain better insight into the genes involved in pathogenicity and in the specific adaptation to the gastric environment of H. suis, a genome analysis was performed of two H. suis strains isolated from the gastric mucosa of swine. Homologs of the vast majority of genes shown to be important for gastric colonization of the human pathogen H. pylori were detected in the H. suis genome. H. suis encodes several putative outer membrane proteins, of which two similar to the H. pylori adhesins HpaA and HorB. H. suis harbours an almost complete comB type IV secretion system and members of the type IV secretion system 3, but lacks most of the genes present in the cag pathogenicity island of H. pylori. Homologs of genes encoding the H. pylori neutrophil-activating protein and γ-glutamyl transpeptidase were identified in H. suis. H. suis also possesses several other presumptive virulence-associated genes, including homologs for mviN, the H. pylori flavodoxin gene, and a homolog of the H. pylori vacuolating cytotoxin A gene. It was concluded that although genes coding for some important virulence factors in H. pylori, such as the cytotoxin-associated protein (CagA), are not detected in the H. suis genome, homologs of other genes associated with colonization and virulence of H. pylori and other bacteria are present.
Collapse
Affiliation(s)
- Miet Vermoote
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Tom Theo Marie Vandekerckhove
- Laboratory for Bioinformatics and Computational Genomics, Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Bram Flahou
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Frank Pasmans
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Annemieke Smet
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Dominic De Groote
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Wim Van Criekinge
- Laboratory for Bioinformatics and Computational Genomics, Department of Molecular Biotechnology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Richard Ducatelle
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Freddy Haesebrouck
- Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| |
Collapse
|
14
|
Lymphocyte proliferative response to Helicobacter pylori antigens in H. pylori-infected patients. Folia Microbiol (Praha) 2011; 55:649-56. [PMID: 21253914 DOI: 10.1007/s12223-010-0105-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 11/16/2010] [Indexed: 01/13/2023]
Abstract
Helicobacter pylori (Hp) contributes to the development of gastric and extra-gastric diseases such as autoimmune thyroiditis (AT), and causes persistent life-long infection despite local and systemic immune response. We determined the specific cellular immune response to Hp antigens and PWM (control mitogen) in two groups of Hp infected patients--group A (n = 21), involving patients with autoimmune thyroiditis and group B (n = 13) of patients without AT--using modified lymphocyte transformation test before and after eradication therapy in comparison with healthy controls (group C, n = 15). Immune reactivity to the majority of Hp antigens (aHp, hHp, HpAg, CagA) was significantly lower in group B before eradication therapy in comparison with healthy Hp negative controls. A significant increase in immune reactivity was observed in group B to certain Hp antigens after successful eradication. The same levels (but insignificant) of immune reactivity were shown in group A. Our results indicate that Hp can cause the inhibition of the specific cellular immune response in Hp infected patients with or without autoimmune diseases such as AT, which can be abrogated by successful eradication of Hp. Lymphocyte transformation test appears to be a good tool for detection of immune memory cellular response in patients with Hp infection.
Collapse
|
15
|
Abstract
Helicobacter pylori is a genetically diverse organism that is adapted for colonization of the human stomach. All strains contain a gene encoding a secreted, pore-forming toxin known as VacA. Genetic variation at this locus could be under strong selection as H. pylori adapts to the host immune response, colonizes new human hosts, or inhabits different host environments. Here, we analyze the molecular evolution of VacA. Phylogenetic reconstructions indicate the subdivision of VacA sequences into three main groups with distinct geographic distributions. Divergence of the three groups is principally due to positively selected sequence changes in the p55 domain, a central region required for binding of the toxin to host cells. Divergent amino acids map to surface-exposed sites in the p55 crystal structure. Comparative phylogenetic analyses of vacA sequences and housekeeping gene sequences indicate that vacA does not share the same evolutionary history as the core genome. Further, rooting the VacA tree with outgroup sequences from the close relative Helicobacter acinonychis reveals that the ancestry of VacA is different from the African origin that typifies the core genome. Finally, sequence analyses of the virulence determinant CagA reveal three main groups strikingly similar to the three groups of VacA sequences. Taken together, these results indicate that positive selection has shaped the phylogenetic structure of VacA and CagA, and each of these virulence determinants has evolved separately from the core genome.
Collapse
|
16
|
Luther J, Dave M, Higgins PD, Kao JY. Association between Helicobacter pylori infection and inflammatory bowel disease: a meta-analysis and systematic review of the literature. Inflamm Bowel Dis 2010; 16:1077-84. [PMID: 19760778 PMCID: PMC4865406 DOI: 10.1002/ibd.21116] [Citation(s) in RCA: 148] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Epidemiologic data suggest a protective effect of Helicobacter pylori infection against the development of autoimmune disease. Laboratory data illustrate H. pylori's ability to induce immune tolerance and limit inflammatory responses. Numerous observational studies have investigated the association between H. pylori infection and inflammatory bowel disease (IBD). Our aim was to perform a systematic review and meta-analysis of this association. METHODS Medline, EMBASE, bibliographies, and meeting abstracts were searched by 2 independent reviewers. Of 369 abstracts reviewed, 30 promising articles were reviewed in detail. Twenty-three studies met our inclusion criteria (subject N = 5903). Meta-analysis was performed with the metan command in Stata 10.1. RESULTS Overall, 27.1% of IBD patients had evidence of infection with H. pylori compared to 40.9% of patients in the control group. The estimated relative risk of H. pylori infection in IBD patients was 0.64 (95% confidence interval [CI]: 0.54-0.75). There was significant heterogeneity in the included studies that could not be accounted for by the method of IBD and H. pylori diagnosis, study location, or study population age. CONCLUSIONS These results suggest a protective benefit of H. pylori infection against the development of IBD. Heterogeneity among studies and the possibility of publication bias limit the certainty of this finding. Further studies investigating the effect of eradication of H. pylori on the development of IBD are warranted. Because environmental hygiene and intestinal microbiota may be strong confounders, further mechanistic studies in H. pylori mouse models are also necessary to further define the mechanism of this negative association.
Collapse
Affiliation(s)
- Jay Luther
- University of Michigan Medical Center, Ann Arbor, Michigan
| | | | | | - John Y. Kao
- University of Michigan Medical Center, Ann Arbor, Michigan
| |
Collapse
|
17
|
Ivie SE, McClain MS, Algood HMS, Lacy DB, Cover TL. Analysis of a beta-helical region in the p55 domain of Helicobacter pylori vacuolating toxin. BMC Microbiol 2010; 10:60. [PMID: 20178613 PMCID: PMC2836311 DOI: 10.1186/1471-2180-10-60] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2009] [Accepted: 02/23/2010] [Indexed: 12/28/2022] Open
Abstract
Background Helicobacter pylori is a gram-negative bacterium that colonizes the human stomach and contributes to the development of gastric cancer and peptic ulcer disease. VacA, a toxin secreted by H. pylori, is comprised of two domains, designated p33 and p55. Analysis of the crystal structure of the p55 domain indicated that its structure is predominantly a right-handed parallel β-helix, which is a characteristic of autotransporter passenger domains. Substitution mutations of specific amino acids within the p33 domain abrogate VacA activity, but thus far, it has been difficult to identify small inactivating mutations within the p55 domain. Therefore, we hypothesized that large portions of the p55 domain might be non-essential for vacuolating toxin activity. To test this hypothesis, we introduced eight deletion mutations (each corresponding to a single coil within a β-helical segment spanning VacA amino acids 433-628) into the H. pylori chromosomal vacA gene. Results All eight of the mutant VacA proteins were expressed by the corresponding H. pylori mutant strains and underwent proteolytic processing to yield ~85 kDa passenger domains. Three mutant proteins (VacA Δ484-504, Δ511-536, and Δ517-544) were secreted and induced vacuolation of mammalian cells, which indicated that these β-helical coils were dispensable for vacuolating toxin activity. One mutant protein (VacA Δ433-461) exhibited reduced vacuolating toxin activity compared to wild-type VacA. Other mutant proteins, including those containing deletions near the carboxy-terminal end of the β-helical region (amino acids Val559-Asn628), exhibited marked defects in secretion and increased susceptibility to proteolytic cleavage by trypsin, which suggested that these proteins were misfolded. Conclusions These results indicate that within the β-helical segment of the VacA p55 domain, there are regions of plasticity that tolerate alterations without detrimental effects on protein secretion or activity, as well as a carboxy-terminal region in which similar alterations result in protein misfolding and impaired secretion. We propose that non-essential β-helical coils and a carboxy-terminal β-helical segment required for proper protein folding and secretion are features shared by numerous autotransporter passenger domains.
Collapse
Affiliation(s)
- Susan E Ivie
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | | | | | | | | |
Collapse
|
18
|
Helicobacter pylori type IV secretion apparatus exploits beta1 integrin in a novel RGD-independent manner. PLoS Pathog 2009; 5:e1000684. [PMID: 19997503 PMCID: PMC2779590 DOI: 10.1371/journal.ppat.1000684] [Citation(s) in RCA: 187] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 11/05/2009] [Indexed: 12/16/2022] Open
Abstract
Translocation of the Helicobacter pylori (Hp) cytotoxin-associated gene A (CagA) effector protein via the cag-Type IV Secretion System (T4SS) into host cells is a major risk factor for severe gastric diseases, including gastric cancer. However, the mechanism of translocation and the requirements from the host cell for that event are not well understood. The T4SS consists of inner- and outer membrane-spanning Cag protein complexes and a surface-located pilus. Previously an arginine-glycine-aspartate (RGD)-dependent typical integrin/ligand type interaction of CagL with α5β1 integrin was reported to be essential for CagA translocation. Here we report a specific binding of the T4SS-pilus-associated components CagY and the effector protein CagA to the host cell β1 Integrin receptor. Surface plasmon resonance measurements revealed that CagA binding to α5β1 integrin is rather strong (dissociation constant, KD of 0.15 nM), in comparison to the reported RGD-dependent integrin/fibronectin interaction (KD of 15 nM). For CagA translocation the extracellular part of the β1 integrin subunit is necessary, but not its cytoplasmic domain, nor downstream signalling via integrin-linked kinase. A set of β1 integrin-specific monoclonal antibodies directed against various defined β1 integrin epitopes, such as the PSI, the I-like, the EGF or the β-tail domain, were unable to interfere with CagA translocation. However, a specific antibody (9EG7), which stabilises the open active conformation of β1 integrin heterodimers, efficiently blocked CagA translocation. Our data support a novel model in which the cag-T4SS exploits the β1 integrin receptor by an RGD-independent interaction that involves a conformational switch from the open (extended) to the closed (bent) conformation, to initiate effector protein translocation. Integrins are single transmembrane proteins present on almost all types of cells. They are composed of an α and a β subunit, which together form the ligand binding pocket, able to interact with extracellular matrix proteins. The best known binding domain on integrin ligands is the RGD domain. Many bacterial, but also viral pathogens exploit this ligand-binding domain to interact with integrins on the host cell. Helicobacter pylori, a common bacterial pathogen associated with gastric diseases, was recently added to this list. One of H. pylori's most important factors associated with gastric pathologies is the CagA protein. This protein is directly injected into host cells through the Cag Type IV Secretion System (cag-T4SS). Previous studies demonstrated that the cag-T4SS requires integrins for the injection (translocation) of CagA into cells. We provide evidence that three proteins, CagA, CagI and CagY, interact with integrins in an RGD-independent way. Additionally, our data point out that the Cag apparatus needs the physical capacity of a β1 integrin heterodimer to change from an active/extended conformation to a closed/bent conformation. This novel kind of integrin interaction opens a new way in which pathogens can use receptors on cells.
Collapse
|
19
|
Jiménez-Soto LF, Kutter S, Sewald X, Ertl C, Weiss E, Kapp U, Rohde M, Pirch T, Jung K, Retta SF, Terradot L, Fischer W, Haas R. Helicobacter pylori type IV secretion apparatus exploits beta1 integrin in a novel RGD-independent manner. PLoS Pathog 2009. [PMID: 19997503 DOI: 10.1371/journal.ppat.1000684.t001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Translocation of the Helicobacter pylori (Hp) cytotoxin-associated gene A (CagA) effector protein via the cag-Type IV Secretion System (T4SS) into host cells is a major risk factor for severe gastric diseases, including gastric cancer. However, the mechanism of translocation and the requirements from the host cell for that event are not well understood. The T4SS consists of inner- and outer membrane-spanning Cag protein complexes and a surface-located pilus. Previously an arginine-glycine-aspartate (RGD)-dependent typical integrin/ligand type interaction of CagL with alpha5beta1 integrin was reported to be essential for CagA translocation. Here we report a specific binding of the T4SS-pilus-associated components CagY and the effector protein CagA to the host cell beta1 Integrin receptor. Surface plasmon resonance measurements revealed that CagA binding to alpha5beta1 integrin is rather strong (dissociation constant, K(D) of 0.15 nM), in comparison to the reported RGD-dependent integrin/fibronectin interaction (K(D) of 15 nM). For CagA translocation the extracellular part of the beta1 integrin subunit is necessary, but not its cytoplasmic domain, nor downstream signalling via integrin-linked kinase. A set of beta1 integrin-specific monoclonal antibodies directed against various defined beta1 integrin epitopes, such as the PSI, the I-like, the EGF or the beta-tail domain, were unable to interfere with CagA translocation. However, a specific antibody (9EG7), which stabilises the open active conformation of beta1 integrin heterodimers, efficiently blocked CagA translocation. Our data support a novel model in which the cag-T4SS exploits the beta1 integrin receptor by an RGD-independent interaction that involves a conformational switch from the open (extended) to the closed (bent) conformation, to initiate effector protein translocation.
Collapse
Affiliation(s)
- Luisa F Jiménez-Soto
- Max von Pettenkofer-Institute for Hygiene and Medical Microbiology, Ludwig-Maximilians-Universität, München, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Fischer W, Prassl S, Haas R. Virulence Mechanisms and Persistence Strategies of the Human Gastric Pathogen Helicobacter pylori. Curr Top Microbiol Immunol 2009; 337:129-71. [DOI: 10.1007/978-3-642-01846-6_5] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
21
|
Torres LE, Melián K, Moreno A, Alonso J, Sabatier CA, Hernández M, Bermúdez L, Rodríguez BL. Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates. World J Gastroenterol 2009. [PMID: 19132771 DOI: 10.3748/wjg.v15.i2.204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients. METHODS DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies. RESULTS vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and "triple-positive" (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively). CONCLUSION The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.
Collapse
Affiliation(s)
- Lino E Torres
- Department of Microbiology and Immunology, Biotechnology Division, National Centre for Scientific Research, Ciudad de La Habana, Cuba
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Torres LE, Melián K, Moreno A, Alonso J, Sabatier CA, Hernández M, Bermúdez L, Rodríguez BL. Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates. World J Gastroenterol 2009. [PMID: 19132771 DOI: 10.3748/wjg.v15.i2.211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients. METHODS DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies. RESULTS vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and "triple-positive" (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively). CONCLUSION The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.
Collapse
Affiliation(s)
- Lino E Torres
- Department of Microbiology and Immunology, Biotechnology Division, National Centre for Scientific Research, Ciudad de La Habana, Cuba
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Torres LE, Melián K, Moreno A, Alonso J, Sabatier CA, Hernández M, Bermúdez L, Rodríguez BL. Prevalence of vacA, cagA and babA2 genes in Cuban Helicobacter pylori isolates. World J Gastroenterol 2009; 15:204-10. [PMID: 19132771 PMCID: PMC2653313 DOI: 10.3748/wjg.15.204] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIM: To investigate the prevalence of vacuolating cytotoxin (vacA), cytotoxin associated gene A (cagA) and blood adhesion binding antigen (babA2) genotypes of Helicobacter pylori (H pylori) isolates from Cuban dyspeptic patients.
METHODS: DNA was extracted from H pylori-positive cultures taken from 130 dyspeptic patients. Genotyping was performed by PCR, using specific primers for vacA (s1, s2, m1, m2), cagA and babA2 genes. Endoscopic observations and histological examinations were used to determine patient pathologies.
RESULTS: vacA alleles s1, s2, m1 and m2 were detected in 96 (73.8%), 34 (26.2%), 75 (57.7%) and 52 isolates (40%), respectively, while the cagA gene was detected in 95 isolates (73.2%). One hundred and seven isolates (82.3%) were babA2-positive. A significant correlation was observed between vacAs1m1 and cagA and between vacAs1m1 and babA2 genotypes (P < 0.001 and P < 0.05, respectively) and between babA2 genotype and cagA status (P < 0.05); but, no correlation was observed between vacAs1 and babA2 genotypes. Eighty five (65.4%) and 73 (56.2%) strains were type 1 (vacAs1-cagA-positive) and “triple-positive” (vacAs1-cagA-babA2-positive), respectively, and their presence was significantly associated with duodenal ulcer (P < 0.01 and P < 0.001, respectively).
CONCLUSION: The distribution of the main virulence factors in the Cuban strains in this study resembled that of the Western-type strains, and the more virulent H pylori isolates were significantly associated with duodenal ulcer, ulcer disease being the worst pathology observed in the group studied.
Collapse
|
24
|
Owen RJ, Xerry J. Geographical conservation of short inserts in the signal and middle regions of the Helicobacter pylori vacuolating cytotoxin gene. MICROBIOLOGY-SGM 2007; 153:1176-1186. [PMID: 17379727 DOI: 10.1099/mic.0.2006/002923-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Short nucleotide sequence inserts within the signal (s) and mid (m) regions of the vacuolating cytotoxin gene (vacA) of Helicobacter pylori provide the basis for defining the allelic forms widely used for strain typing and as markers for toxin functionality and severity of interactions with host gastric epithelial cells. Here 484 signal region and 411 mid-region sequences (new and from public databases) from 32 countries were analysed to determine the effect of geographical location on insert diversity, which is currently undefined. Short (27 bp) inserts of 52 mol% G+C from 201 sequences (98 %) of the s2 allelic family encoded a highly conserved nine amino acid sequence irrespective of geographical origin. The longer (75 bp) mid-region insert of 38 mol% G+C in 255 sequences of the m2 allelic family was more diverse and represented by 23 peptide variants, with one predominant sequence (MRI type 4) representing 62 % of inserts. Mid-region inserts were widespread throughout European/North American (Western) sequences in the dataset whereas a lower insert frequency was a geographical feature of East Asian sequences. Each insert was preceded by an associated conserved motif that provided a marker of the insertion sites within vacA, and facilitated identification of the Chinese m2b genotype. It is concluded that the observed sequence conservation supports the continued global use of vacA genotyping, and that inserts could have a functional significance in the mature protein, particularly the s2 form of the toxin, as the same combination of signal and mid-region insert type and preinsert motif was highly conserved.
Collapse
Affiliation(s)
- Robert J Owen
- Campylobacter and Helicobacter Research/Reference Unit, Laboratory of Enteric Pathogens, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5HT, UK
| | - Jacqueline Xerry
- Campylobacter and Helicobacter Research/Reference Unit, Laboratory of Enteric Pathogens, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5HT, UK
| |
Collapse
|
25
|
Abstract
For more than 10 years a vaccine against Helicobacter pylori has been the elusive goal of many investigators. The need for a vaccine was highlighted when eradication attempts in developing countries were foiled by reinfection rates of 15-30% per annum. In addition, physicians in developed countries were concerned that attempts at total eradication of H. pylori would result in widespread macrolide resistance in both H. pylori and other important pathogens. Although attempts to produce vaccines against H. pylori have failed in their ultimate goal, considerable knowledge has been developed on the pathogenesis and immunology of Helicobacter infections. In this article we describe an alternative use for this new knowledge, i.e. a plan to use live Helicobacter species to deliver vaccines against other organisms. Because of its intimate attachment to the gastric mucosa and long-term residence there, H. pylori might succeed as an antigen delivery system, a goal which has eluded most other strategies of nonparenteral vaccination.
Collapse
Affiliation(s)
- Barry Marshall
- Helicobacter pylori Research Laboratory, Microbiology and Immunology, University of Western Australia, Perth, Western Australia, Australia.
| | | |
Collapse
|
26
|
Godoy APO, Miranda MCB, Paulino LC, Mendonça S, Ribeiro ML, Pedrazzoli Jr. J. Análise das impressões digitais de DNA e de fatores de virulência de linhagens de Helicobacter pylori. ARQUIVOS DE GASTROENTEROLOGIA 2007; 44:107-12. [DOI: 10.1590/s0004-28032007000200004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2005] [Accepted: 10/05/2006] [Indexed: 11/22/2022]
Abstract
RACIONAL: Helicobacter pylori é hoje aceito como o principal agente etiológico de gastrite em seres humanos e fator de risco para úlcera péptica e câncer gástrico. A evolução da infecção está relacionada a diversos fatores, inclusive bacterianos, como presença do gene cagA e o genótipo vacA s1m1, associados ao desenvolvimento de úlcera e adenocarcinoma gástrico. A técnica de RAPD ("random amplified polimorphic") tem sido amplamente utilizada para obtenção de impressões digitais de DNA para examinar a similaridade entre linhagens. OBJETIVOS: Avaliar a presença de cagA e alelos do vacA em amostras de H. pylori e associar os achados com a doença apresentada e também investigar possível clonicidade entre os fatores de virulência e as doenças com a impressão digital de DNA gerada pelo RAPD-PCR. MÉTODOS: Foram incluídas 112 amostras provenientes de pacientes com diferentes laudos endoscópicos: gastrite (n = 41), esofagite de refluxo (n = 14), úlcera gástrica (n = 19) e úlcera duodenal (n = 38). A análise dos fatores de virulência da bactéria foi feita por PCR e as impressões digitais de DNA foram estabelecidas pelo método de RAPD-PCR. RESULTADOS: Os resultados obtidos indicam que houve uma associação significativa entre úlcera duodenal e o mosaico vacA s1m1. Analisando-se os padrões de bandas geradas pelo RAPD-PCR, sete diferentes dendogramas foram construídos e não foi possível detectar associação significativa entre os agrupamentos, sugerindo que as amostras não possuem perfil clonal. CONCLUSÃO: Os resultados reforçam a importância do gene vacA como um marcador de virulência do H. pylori. O RAPD da impressão digital de DNA realizado foi incapaz de associar o padrão de bandas com as enfermidades e os genótipos de vacA e cagA.
Collapse
|
27
|
Abstract
Helicobacter pylori, a Gram-negative flagellate bacterium that infects the stomach of more than half of the global population, is regarded as the leading cause of chronic gastritis, peptic ulcer disease, and even gastric adenocarcinoma in some individuals. Although the bacterium induces strong humoral and cellular immune responses, it can persist in the host for decades. It has several virulence factors, some of them having vaccine potential as judged by immunoproteomic analysis. A few vaccination studies involving a small number of infected or uninfected humans with various H. pylori formulations such as the recombinant urease, killed whole cells, and live Salmonella vectors presenting the subunit antigens have not provided satisfactory results. One trial that used the recombinant H. pylori urease coadministered with native Escherichia coli enterotoxin (LT) demonstrated a reduction of H. pylori load in infected participants. Although extensive studies in the mouse model have demonstrated the feasibility of both therapeutic and prophylactic immunizations, the mechanism of vaccine-induced protection is poorly understood as several factors such as immunoglobulin and various cytokines do not contribute to protection. Transcriptome analyses in mice have indicated the role of nonclassical immune factors in vaccine-induced protection. The role of regulatory T cells in the persistence of H. pylori infection has also been suggested. A recently developed experimental H. pylori infection model in humans may be used for testing several new adjuvants and vaccine delivery systems that have been currently obtained. The use of vaccines with appropriate immunogens, routes of immunization, and adjuvants along with a better understanding of the mechanism of immune protection may provide more favorable results.
Collapse
Affiliation(s)
- Shahjahan Kabir
- Academic Research and Information Management, Uppsala, Sweden.
| |
Collapse
|
28
|
Necchi V, Candusso ME, Tava F, Luinetti O, Ventura U, Fiocca R, Ricci V, Solcia E. Intracellular, intercellular, and stromal invasion of gastric mucosa, preneoplastic lesions, and cancer by Helicobacter pylori. Gastroenterology 2007; 132:1009-23. [PMID: 17383424 DOI: 10.1053/j.gastro.2007.01.049] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2006] [Accepted: 11/30/2006] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS It is not clear how Helicobacter pylori, an apparently extracellular pathogen colonizing the luminal side of the gastric epithelium, invariably causes an immune-inflammatory response on the stromal side of the mucosa. Penetration of H pylori into epithelial cell lines and its interaction with immune-inflammatory cells have been documented in vitro. Several investigations also showed in vivo bacterial penetration into the epithelium up to the lamina propria; however, the identification as H pylori of the bacteria-like bodies observed in unchanged, metaplastic, or neoplastic mucosa remained sometimes questionable. METHODS To search for bacteria-like organisms, we used transmission electron microscopy on endoscopic biopsy specimens from 20 dyspeptic subjects and surgical specimens of neoplastic and nonneoplastic mucosa from 20 cancerous stomachs. To ascertain the H pylori nature of the organisms found, we used 6 different antibodies directed against bacterial lysates, purified vacuolating cytotoxin A, or purified cytotoxin-associated antigen A in immunogold tests. The results were compared with those of H pylori strains cultivated in vitro. RESULTS In nonmetaplastic gastric epithelium, cytochemically proven H pylori were detected, in the majority of cases, inside cytoplasm of epithelial cells, in intraepithelial intercellular spaces, and in underlying lamina propria, often in direct contact with immune-inflammatory cells and sometimes inside small blood vessels. Cytochemically proven H pylori were also observed inside 6 of 8 intestinal metaplasias and 9 of 20 cancers. CONCLUSIONS H pylori penetrates normal, metaplastic, and neoplastic gastric epithelium in vivo, intracellularly, or interstitially to cause a strong immune-inflammatory response and promote gastric carcinogenesis.
Collapse
Affiliation(s)
- Vittorio Necchi
- Department of Human Pathology, University of Pavia, Pavia, Italy
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Terebiznik MR, Vazquez CL, Torbicki K, Banks D, Wang T, Hong W, Blanke SR, Colombo MI, Jones NL. Helicobacter pylori VacA toxin promotes bacterial intracellular survival in gastric epithelial cells. Infect Immun 2006; 74:6599-614. [PMID: 17000720 PMCID: PMC1698066 DOI: 10.1128/iai.01085-06] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Helicobacter pylori colonizes the gastric epithelium of at least 50% of the world's human population, playing a causative role in the development of chronic gastritis, peptic ulcers, and gastric adenocarcinoma. Current evidence indicates that H. pylori can invade epithelial cells in the gastric mucosa. However, relatively little is known about the biology of H. pylori invasion and survival in host cells. Here, we analyze both the nature of and the mechanisms responsible for the formation of H. pylori's intracellular niche. We show that in AGS cells infected with H. pylori, bacterium-containing vacuoles originate through the fusion of late endocytic organelles. This process is mediated by the VacA-dependent retention of the small GTPase Rab7. In addition, functional interactions between Rab7 and its downstream effector, Rab-interacting lysosomal protein (RILP), are necessary for the formation of the bacterial compartment since expression of mutant forms of RILP or Rab7 that fail to bind each other impaired the formation of this unique bacterial niche. Moreover, the VacA-mediated sequestration of active Rab7 disrupts the full maturation of vacuoles as assessed by the lack of both colocalization with cathepsin D and degradation of internalized cargo in the H. pylori-containing vacuole. Based on these findings, we propose that the VacA-dependent isolation of the H. pylori-containing vacuole from bactericidal components of the lysosomal pathway promotes bacterial survival and contributes to the persistence of infection.
Collapse
Affiliation(s)
- M R Terebiznik
- Hospital for Sick Children, 555 University Avenue, Toronto, Canada M5G 1X9
| | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Anderson KM, Czinn SJ, Redline RW, Blanchard TG. Induction of CTLA-4-mediated anergy contributes to persistent colonization in the murine model of gastric Helicobacter pylori infection. THE JOURNAL OF IMMUNOLOGY 2006; 176:5306-13. [PMID: 16621997 DOI: 10.4049/jimmunol.176.9.5306] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Helicobacter pylori infection induces gastric inflammation but the host fails to generate protective immunity. Therefore, we evaluated the immunologic mechanisms that contribute to the failure of the T cells to promote active immunity to H. pylori in the mouse model of H. pylori infection. Spleen cells from infected C57BL/6 mice underwent significantly less proliferation and cytokine production than cells from immune mice upon in vitro stimulation with H. pylori lysate. Similar results were observed when stimulating with Ag-pulsed macrophages demonstrating that hyporesponsiveness was not due to a direct effect of H. pylori virulence factors on the T cells. Ag-specific hyporesponsiveness could be reversed by the addition of high-dose IL-2 but not by removal of CD4(+)CD25(+) T cells, indicating that hyporesponsiveness was due to anergy and not due to active suppression. Cells from infected mice lacked significant suppressor activity as shown by the failure to reduce the recall response of cells from immune mice in coculture at physiologic ratios. Direct blockade of CTLA-4 using anti-CTLA-4 Fabs or indirect blockade using CTLA-4 Ig plus anti-CD28 Ab resulted in significantly increased T cell activation in vitro. The importance of CTLA-4 in establishing anergy was confirmed in an in vivo model of H. pylori infection in which mice that received anti-CTLA-4 Fabs responded to H. pylori challenge with significantly greater inflammation and significantly reduced bacterial load. These results suggest that CTLA-4 engagement induces and maintains functional inactivation of H. pylori-specific T cells during H. pylori infection resulting in a reduced immune response.
Collapse
Affiliation(s)
- Kathleen M Anderson
- Department of Pathology, School of Medicine, Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | | | | | | |
Collapse
|
31
|
Park H, Kim NI, Kim JM, Kim JS, Oh YK, Kim YJ, Kim N, Jung HC, Song IS. Expression of Eotaxin in Gastric Epithelial Cells Stimulated withHelicobacter pyloriVacuolating Cytotoxin. ACTA ACUST UNITED AC 2006. [DOI: 10.4167/jbv.2006.36.1.11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Hyokhan Park
- Department of Microbiology, Hanyang University College of Medicine, Korea
| | - Nam In Kim
- Department of Microbiology, Hanyang University College of Medicine, Korea
| | - Jung Mogg Kim
- Department of Microbiology, Hanyang University College of Medicine, Korea
| | - Joo Sung Kim
- Department of Internal Medicine and Institute of Liver Research, Seoul National University College of Medicine, Korea
| | - Yu-Kyoung Oh
- School of Life Sciences and Biotechnology, Korea University, Korea
| | | | - Nayoung Kim
- Department of Internal Medicine and Institute of Liver Research, Seoul National University College of Medicine, Korea
| | - Hyun Chae Jung
- Department of Internal Medicine and Institute of Liver Research, Seoul National University College of Medicine, Korea
| | - In Sung Song
- Department of Internal Medicine and Institute of Liver Research, Seoul National University College of Medicine, Korea
| |
Collapse
|
32
|
Tuccillo C, Cuomo A, Rocco A, Martinelli E, Staibano S, Mascolo M, Gravina AG, Nardone G, Ricci V, Ciardiello F, Del Vecchio Blanco C, Romano M. Vascular endothelial growth factor and neo-angiogenesis in H. pylori gastritis in humans. J Pathol 2005; 207:277-84. [PMID: 16184519 DOI: 10.1002/path.1844] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Host response plays a major role in the pathogenesis of Helicobacter pylori-induced gastroduodenal disease including adenocarcinoma of the distal stomach. Vascular endothelial growth factor (VEGF) is an important modulator of gastric mucosal repair and is overexpressed in gastric cancer. The present study sought to evaluate the expression of VEGF in the gastric mucosa of H. pylori-infected and H. pylori-non-infected dyspeptic patients. Fifteen H. pylori-infected and 15 H. pylori-non-infected dyspeptic patients were studied. Diagnosis of H. pylori infection was based on rapid urease test and histology. VEGF protein expression was assessed by western blotting. VEGF mRNA expression was assessed by RT-PCR. VEGF localization in the gastric mucosa and neo-angiogenesis were determined by immunohistochemistry. VEGF protein and mRNA expression was significantly greater in H. pylori-infected than in non-infected patients. Immunohistochemistry showed that VEGF expression was more intense in the gastric gland compartment of H. pylori-infected mucosa than in the non-infected mucosa. The increase in VEGF expression was associated with a significant increase in neo-angiogenesis as assessed by determination of CD34-positive micro-vessels. H. pylori gastritis is therefore associated with up-regulation of VEGF expression, which parallels the increased formation of blood vessels in the gastric mucosa. It is postulated that increased VEGF expression and neo-angiogenesis may contribute to H. pylori-related gastric carcinogenesis.
Collapse
Affiliation(s)
- Concetta Tuccillo
- Dipartimento di Internistica Clinica e Sperimentale-Cattedra di Gastroenterologia, Seconda Università di Napoli, Napoli, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
El-Bez C, Adrian M, Dubochet J, Cover TL. High resolution structural analysis of Helicobacter pylori VacA toxin oligomers by cryo-negative staining electron microscopy. J Struct Biol 2005; 151:215-28. [PMID: 16125415 DOI: 10.1016/j.jsb.2005.07.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Revised: 07/05/2005] [Accepted: 07/07/2005] [Indexed: 12/28/2022]
Abstract
Helicobacter pylori secretes a vacuolating toxin (VacA) that can assemble into water-soluble oligomeric complexes and insert into membranes to form anion-selective channels. Previous studies have described multiple types of oligomeric VacA structures, including single-layered astral arrays, bilayered forms, and two-dimensional crystalline arrays. In the current study, vitrified VacA complexes were examined by cryo-negative staining electron microscopy, views of the different oligomeric structures in multiple orientations were classified and analyzed, and three-dimensional models of the bilayered forms of VacA were constructed with a resolution of about 19 angstroms. These bilayered forms of VacA have a "flower"-like structure, consisting of a central ring surrounded by symmetrically arranged peripheral "petals." Further structural insights were obtained by analyzing a mutant form of VacA (VacADelta6-27), which lacks a unique amino-terminal hydrophobic segment and is defective in the capacity to form membrane channels. Bilayered oligomeric complexes formed by wild-type VacA contained a visible density within the central ring, whereas bilayered complexes formed by VacADelta6-27 lacked this density. These results indicate that deletion of the VacA amino-terminal hydrophobic region causes a structural alteration in the central ring within VacA oligomers, and suggest that the central ring plays an important role in the process by which VacA forms membrane channels.
Collapse
Affiliation(s)
- Catherine El-Bez
- Laboratoire d'Analyse Ultrastructurale, Bâtiment de Biologie, Université de Lausanne, Lausanne, Switzerland.
| | | | | | | |
Collapse
|
34
|
Ricci V, Chiozzi V, Necchi V, Oldani A, Romano M, Solcia E, Ventura U. Free-soluble and outer membrane vesicle-associated VacA from Helicobacter pylori: Two forms of release, a different activity. Biochem Biophys Res Commun 2005; 337:173-8. [PMID: 16182250 DOI: 10.1016/j.bbrc.2005.09.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Accepted: 09/07/2005] [Indexed: 11/29/2022]
Abstract
Helicobacter pylori releases VacA both as free-soluble and as outer membrane vesicle (OMV)-associated toxin. In this study, we investigated the amount of VacA released in each of the two forms and the role of each form in VacA-induced cell vacuolation in vitro. We found that: (1) free-soluble toxin accounted for about 75% of released VacA, while the remaining 25% was OMV-associated; (2) although OMV-associated VacA caused a statistically significant vacuolation, virtually all the vacuolating activity of a H. pylori broth culture filtrate was due to free-soluble VacA. While it is widely accepted that OMVs may represent an important vehicle for delivering virulence factors to the gastric mucosa, our results suggest that OMV-associated VacA could play a pathobiological role different from that of free-soluble toxin. This conclusion fits with mounting evidence that VacA exerts a large pattern of pathobiological effects among which cell vacuolation might not be the main one.
Collapse
Affiliation(s)
- Vittorio Ricci
- Department of Experimental Medicine, Human Physiology Section, Pavia University, Pavia, Italy.
| | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
PURPOSE OF REVIEW Virulence factors are related to the ability of a microbe to induce disease. True virulence factors must therefore have a disease association, an in-vivo correlate with disease such as increased mucosal inflammation, or both. RECENT FINDINGS The cytotoxin-associated gene pathogenicity island; the outer membrane inflammatory protein; the duodenal ulcer-promoting gene, and possibly the blood group antigen-binding adhesion, are the only factors that to date qualify as virulence factors. Numerous recent studies have investigated the interaction of vacuolating cytotoxin A or cytotoxin-associated gene A with cells and cell lines in vitro. It remains unclear, however, whether any of the findings, for example, in-vitro experiments showing that vacuolating cytotoxin A affect the regulation of T or B lymphocytes, have an in-vivo counterpart, or play any role in disease pathogenesis. SUMMARY The criteria for a virulence factor include evidence of an association with a disease or a disease surrogate such as the severity of mucosal inflammation, epidemiologic consistency, and biologic plausibility. Confirmation of the proposed mechanism requires elimination of the effect by gene deletion and restoration by complementation. Cytotoxin-associated gene A has been the subject of elegant biochemistry despite lack of evidence that it is involved in pathogenesis. The current focus of research on Helicobacter pylori relates to exploring the biology of Helicobacter pylori, often using systems that only vaguely relate to the in-vivo conditions or to disease pathogenesis.
Collapse
Affiliation(s)
- Hong Lu
- Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center, and Baylor College of Medicine, Houston, TX 77030, USA
| | | | | |
Collapse
|
36
|
Radosz-Komoniewska H, Bek T, Jóźwiak J, Martirosian G. Pathogenicity of Helicobacter pylori infection. Clin Microbiol Infect 2005; 11:602-10. [PMID: 16008611 DOI: 10.1111/j.1469-0691.2005.01207.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Numerous Helicobacter pylori virulence factors, including various enzymes (urease, catalase, lipase, phospholipase and proteases), vacuolating cytotoxin (a product of expression of the vacA gene), and the immunogenic protein CagA, encoded by the cagA gene localised in the H. pylori pathogenicity island, are involved in the pathomechanism of infection caused by these organisms. This review presents the current state of knowledge concerning the molecular mechanisms and epidemiology of H. pylori infection, based on the published literature and recent unpublished observations.
Collapse
Affiliation(s)
- H Radosz-Komoniewska
- Department of Medical Microbiology, Medical University of Silesia, Katowice, Poland
| | | | | | | |
Collapse
|
37
|
Fitchen N, Letley DP, O'Shea P, Atherton JC, Williams P, Hardie KR. All subtypes of the cytotoxin VacA adsorb to the surface of Helicobacter pylori post-secretion. J Med Microbiol 2005; 54:621-630. [PMID: 15947426 DOI: 10.1099/jmm.0.45946-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The major secreted virulence factor of Helicobacter pylori, the vacuolating cytotoxin VacA, is known to insert into eukaryotic membranes and has been observed in association with the surface of H. pylori cells that are actively producing it. Here, it is demonstrated that VacA is capable of interacting with the surface of H. pylori and Escherichia coli after secretion. It is shown that this interaction is resistant to disruption of electrostatic and hydrophobic forces, and that it appears to occur despite truncation of LPS and the removal of trypsin-accessible surface proteins. Adsorption to bacterial cell surfaces was independent of the VacA subtype, suggesting that it is not mediated through recognition of a known receptor by the VacA p58 subunit. Similarly, adsorption to bacterial cell surfaces is unlikely to be instigated by the extreme N-terminus of VacA, since a hydrophilic extension at this location that is known to disrupt VacA-induced vacuolation did not interfere with adsorption to H. pylori cells.
Collapse
Affiliation(s)
- Nicola Fitchen
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| | - Darren P Letley
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| | - Paul O'Shea
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| | - John C Atherton
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| | - Paul Williams
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| | - Kim R Hardie
- Institute of Infection, Immunity, and Inflammation, University of Nottingham, Centre for Biomolecular Sciences, University Park, Nottingham NG7 2RH, UK 2Wolfson Digestive Diseases Centre, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK 3School of Biomedical Sciences, Queen's Medical School, Nottingham NG7 2UH, UK
| |
Collapse
|
38
|
Torres VJ, Ivie SE, McClain MS, Cover TL. Functional properties of the p33 and p55 domains of the Helicobacter pylori vacuolating cytotoxin. J Biol Chem 2005; 280:21107-14. [PMID: 15817461 DOI: 10.1074/jbc.m501042200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Helicobacter pylori secretes an 88-kDa vacuolating cytotoxin (VacA) that may contribute to the pathogenesis of peptic ulcer disease and gastric cancer. VacA cytotoxic activity requires assembly of VacA monomers into oligomeric structures, formation of anion-selective membrane channels, and entry of VacA into host cells. In this study, we analyzed the functional properties of recombinant VacA fragments corresponding to two putative VacA domains (designated p33 and p55). Immunoprecipitation experiments indicated that these two domains can interact with each other to form protein complexes. In comparison to the individual VacA domains, a mixture of the p33 and p55 proteins exhibited markedly enhanced binding to the plasma membrane of mammalian cells. Furthermore, internalization of the VacA domains was detected when cells were incubated with the p33/p55 mixture but not when the p33 and p55 proteins were tested individually. Incubation of cells with the p33/p55 mixture resulted in cell vacuolation, whereas the individual domains lacked detectable cytotoxic activity. Interestingly, sequential addition of p55 followed by p33 resulted in VacA internalization and cell vacuolation, whereas sequential addition in the reverse order was ineffective. These results indicate that both the p33 and p55 domains contribute to the binding and internalization of VacA and that both domains are required for vacuolating cytotoxic activity. Reconstitution of toxin activity from two separate domains, as described here for VacA, has rarely been described for pore-forming bacterial toxins, which suggests that VacA is a pore-forming toxin with unique structural properties.
Collapse
Affiliation(s)
- Victor J Torres
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-2605, USA
| | | | | | | |
Collapse
|