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Lind J, Backert S, Pfleiderer K, Berg DE, Yamaoka Y, Sticht H, Tegtmeyer N. Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of Western-type Helicobacter pylori strains. PLoS One 2014; 9:e96488. [PMID: 24800748 PMCID: PMC4011759 DOI: 10.1371/journal.pone.0096488] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 04/09/2014] [Indexed: 12/14/2022] Open
Abstract
The clinical outcome of Helicobacter pylori infections is determined by multiple host-pathogen interactions that may develop to chronic gastritis, and sometimes peptic ulcers or gastric cancer. Highly virulent strains encode a type IV secretion system (T4SS) that delivers the effector protein CagA into gastric epithelial cells. Translocated CagA undergoes tyrosine phosphorylation at EPIYA-sequence motifs, called A, B and C in Western-type strains, by members of the oncogenic Src and Abl host kinases. Phosphorylated EPIYA-motifs mediate interactions of CagA with host signaling factors--in particular various SH2-domain containing human proteins--thereby hijacking multiple downstream signaling cascades. Observations of tyrosine-phosphorylated CagA are mainly based on the use of commercial phosphotyrosine antibodies, which originally were selected to detect phosphotyrosines in mammalian proteins. Systematic studies of phosphorylated EPIYA-motif detection by the different antibodies would be very useful, but are not yet available. To address this issue, we synthesized phospho- and non-phosphopeptides representing each predominant Western CagA EPIYA-motif, and determined the recognition patterns of seven different phosphotyrosine antibodies in Western blots, and also performed infection studies with diverse representative Western H. pylori strains. Our results show that a total of 9-11 amino acids containing the phosphorylated EPIYA-motifs are necessary and sufficient for specific detection by these antibodies, but revealed great variability in sequence recognition. Three of the antibodies recognized phosphorylated EPIYA-motifs A, B and C similarly well; whereas preferential binding to phosphorylated motif A and motifs A and C was found with two and one antibodies, respectively, and the seventh anti-phosphotyrosine antibody did not recognize any phosphorylated EPIYA-motif. Controls showed that none of the antibodies recognized the corresponding non-phospho CagA peptides, and that all of them recognized phosphotyrosines in mammalian proteins. These data are valuable in judicious application of commercial anti-phosphotyrosine antibodies and in characterization of CagA phosphorylation during infection and disease development.
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Affiliation(s)
- Judith Lind
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Steffen Backert
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Klaus Pfleiderer
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
| | - Douglas E. Berg
- Division of Infectious Disease, Department of Medicine, University of California San Diego, La Jolla, California, United States of America
| | - Yoshio Yamaoka
- Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan
| | - Heinrich Sticht
- Friedrich Alexander University Erlangen-Nuremberg, Bioinformatics, Institute for Biochemistry, Erlangen, Germany
| | - Nicole Tegtmeyer
- Friedrich Alexander University Erlangen-Nuremberg, Department of Biology, Division of Microbiology, Erlangen, Germany
- * E-mail:
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Basiri Z, Safaralizadeh R, Bonyadi MJ, Somi MH, Mahdavi M, Latifi-Navid S. Helicobacter pylori vacA d1 genotype predicts risk of gastric adenocarcinoma and peptic ulcers in northwestern Iran. Asian Pac J Cancer Prev 2014; 15:1575-9. [PMID: 24641370 DOI: 10.7314/apjcp.2014.15.4.1575] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND There is a close relationship between Helicobacter pylori (H pylori)-specific factors and different gastroduodenal diseases. The present study aimed to investigate the prevalence of vacA d1, d2 genotypes in the H pylori isolates from patients with gastric adenocarcinoma, peptic ulcer disease (PUD) and gastritis in East Azerbaijan region, where the incidence of gastric cancer (GC) is high. Strains isolated from this area are likely to be of European ancestry. MATERIALS AND METHODS In this study, genotyping of the vacA d region of 115 isolates obtained from patients with different gastrodoudenal diseases was accomplished by PCR methods. In addition to PCR amplification of H pylori 16S rDNA, rapid urease tests or histological examination were used to confirm the presence of H pylori in biopsy specimens. Data were collected and analyzed using SPSS version 19. RESULTS Of the total of 83 H pylori isolates, 36 (43.4%) contained the d1 allele and 47 (56.6%) were subtype d2. The results of the multiple linear/logistic regression analysis showed high correlation between allele d1 and gastric adenocarcinoma or PUD. CONCLUSIONS This study suggests that the H pylori vacA d1 genotype helps predict risk for gastric adenocarcinoma and PUD in East Azerbaijan, Iran.
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Affiliation(s)
- Zeinab Basiri
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran E-mail :
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53
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Abstract
Helicobacter pylori (H. pylori) infection is linked to various gastroduodenal diseases; however, only a small fraction of these patients develop associated diseases. Despite the high prevalence of H. pylori infection in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than those in other countries. The incidence of gastric cancer tends to decrease from north to south in East Asia. Such geographical differences in the pathology can be explained, at least in part, by the presence of different types of H. pylori virulence factors in addition to host and environmental factors. Virulence factors of H. pylori, such as CagA, VacA, DupA, IceA, OipA and BabA, have been demonstrated to be the predictors of severe clinical outcomes. Interestingly, a meta-analysis showed that CagA seropositivity was associated with gastric cancer compared with gastritis, even in East Asian countries where almost the strains possess cagA. Another meta-analysis also confirmed the significance of vacA, dupA and iceA. However, it is possible that additional important pathogenic genes may exist because H. pylori consists of approximately 1600 genes. Despite the advances in our understanding of the development of H. pylori infection-related diseases, further work is required to clarify the roles of H. pylori virulence factors.
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Affiliation(s)
- Seiji SHIOTA
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
,Department of General Medicine, Oita University Faculty of Medicine, Yufu-City, Oita, Japan
| | - Rumiko SUZUKI
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
| | - Yoshio YAMAOKA
- Department of Environmental and Preventive Medicine, Yufu-City, Oita, Japan
,Department of Medicine-Gastroenterology, Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas, USA
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Vaziri F, Najar Peerayeh S, Alebouyeh M, Molaei M, Maghsoudi N, Zali MR. Determination of Helicobacter pylori CagA EPIYA types in Iranian isolates with different gastroduodenal disorders. INFECTION GENETICS AND EVOLUTION 2013; 17:101-5. [PMID: 23567822 DOI: 10.1016/j.meegid.2013.03.048] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 03/21/2013] [Accepted: 03/30/2013] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori (H. pylori) cytotoxin-associated gene A protein (CagA) is the first bacterial oncoprotein identified in human gastric cancer. The carboxy terminus (C-terminus) of CagA may undergo polymorphisms to give different types of EPIYA motifs, which may exist in single or combination form within the infected host. Sequence variations in the 3' region of the cagA impose a functional impact to the translated CagA protein. In this study, we characterize the diversity of the H. pylori CagA EPIYA types, their associations with their hosts' clinical status, and the potential of using the whole 3' region of cagA as a genetic marker for the identification of Iranian isolates from different geographic locations. H. pylori was detected in 71 out of 177 examined Iranian patients with different gastroduodenal disorders. Genotyping of the cagA variable EPIYA motif was screened by polymerase chain reaction and gene sequencing was performed for all the detected cagA positive isolates. Out of 44 cagA-positive isolates, there were EPIYA motifs of ABC (30 isolates), ABCC (4 isolates), ABCCC (1 isolate), mixed types (6 isolates) and new types (3 isolates). We termed the newly identified EPIYA segment as EPIYA- A-B/C. Sequence analysis also showed the presence of uncommon EPIYA-like motifs (EPIYT and QPIYP) in some isolates. It is postulated that EPIYA type conversion through the presence of different repetitive sequences give rise to these new strains. We also identified 3 sequence motifs which may be applied as genetic markers for Iranian strains. Furthermore, EPIYA types ABCC and EPIYA- A-B/C showed association with duodenitis and gastric cancer, respectively. Further study with a larger number of strains is necessary to confirm the proposed associations and the identified sequence motifs as genetic markers. In conclusion, our study demonstrates the dominancy of Western type cagA gene and the diversity of the CagA C-terminal region in the tested Iranian strains.
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Affiliation(s)
- Farzam Vaziri
- Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Tertiary structure-function analysis reveals the pathogenic signaling potentiation mechanism of Helicobacter pylori oncogenic effector CagA. Cell Host Microbe 2013; 12:20-33. [PMID: 22817985 DOI: 10.1016/j.chom.2012.05.010] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 04/06/2012] [Accepted: 05/07/2012] [Indexed: 02/06/2023]
Abstract
The Helicobacter pylori type IV secretion effector CagA is a major bacterial virulence determinant and critical for gastric carcinogenesis. Upon delivery into gastric epithelial cells, CagA localizes to the inner face of the plasma membrane, where it acts as a pathogenic scaffold/hub that promiscuously recruits host proteins to potentiate oncogenic signaling. We find that CagA comprises a structured N-terminal region and an intrinsically disordered C-terminal region that directs versatile protein interactions. X-ray crystallographic analysis of the N-terminal CagA fragment (residues 1-876) revealed that the region has a structure comprised of three discrete domains. Domain I constitutes a mobile CagA N terminus, while Domain II tethers CagA to the plasma membrane by interacting with membrane phosphatidylserine. Domain III interacts intramolecularly with the intrinsically disordered C-terminal region, and this interaction potentiates the pathogenic scaffold/hub function of CagA. The present work provides a tertiary-structural basis for the pathophysiological/oncogenic action of H. pylori CagA.
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56
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Shiota S, Murakawi K, Suzuki R, Fujioka T, Yamaoka Y. Helicobacter pylori infection in Japan. Expert Rev Gastroenterol Hepatol 2013; 7:35-40. [PMID: 23265147 PMCID: PMC3732492 DOI: 10.1586/egh.12.67] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The prevalence of Helicobacter pylori infection is gradually decreasing in Japan. On the main island of Japan, nearly all H. pylori isolates possess cagA and vacA with strong virulence. However, less virulent H. pylori strains are frequently found in Okinawa where cases of gastric cancer are the lowest in Japan. Eradication therapy for peptic ulcer, idiopathic thrombocytopenic purpura, gastric mucosa-associated lymphoid tissue lymphoma and early gastric cancer after endoscopic resection has been approved by the Japanese national health insurance system. However, the Japanese Society for Helicobacter Research recently stated that all 'H. pylori infection' was considered as the indication for eradication irrespective of the background diseases. To eliminate H. pylori in Japan, the Japanese health insurance system should approve the eradication of all H. pylori infections.
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Affiliation(s)
- Seiji Shiota
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan,Department of General Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan
| | - Kazunari Murakawi
- Department of General Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan
| | - Rumiko Suzuki
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan
| | - Toshio Fujioka
- Department of General Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan
| | - Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593, Japan,Department of Medicine–Gastroenterology, Baylor College of Medicine and Michael E. Debakey Veterans Affairs Medical Center, 2002 Holcombe Blvd. Houston, TX 77030, USA,Author for correspondence: Tel.: +81 975 865 740, Fax: +81 975 865 749,
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Detection of primary clarithromycin resistance of Helicobacter pylori and association between cagA (+) status and clinical outcome. Folia Microbiol (Praha) 2012; 58:141-6. [PMID: 22956464 DOI: 10.1007/s12223-012-0192-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 08/24/2012] [Indexed: 02/07/2023]
Abstract
Helicobacter pylori was examined in 110 patients (82 (74.5) with gastritis, 18 (16.4) with duodenitis, six (5.5) with duodenal ulcer and gastroesophageal reflux, and four (3.6 %) with normal) with gastrointestinal problems living in rural area, no history of macrolide use, and detected by culture (71.8) or direct detection from gastric biopsies by PCR (82.7 %). Also, cagA gene was identified using PCR and was found positive in 68/91 (74.7 %) strains. The prevalence of clarithromycin-resistant H. pylori was investigated by two methods including PCR-RFLP (7.7 (A2142G 1.1 and A2143G 6.6 %)) and twofold agar dilution (8.9 %) to detect phenotypic and genotypic status simultaneously. Among all the H. pylori positive patients, eight (8.8 %) isolates were found to be resistant to clarithromycin by at least one of the AD and/or PCR-RFLP methods. H. pylori positive rates were significantly correlated with patients' sex, age, and endoscopic findings (p = 0.040, <0.001 and <0.001, respectively). There were no differences in gender or endoscopic findings related to cagA (+) and cagA (-) patients. The gene of cagA was not significantly helpful in predicting the clinical outcome of H. pylori infection alone. In conclusion, we revealed that there was a low prevalence of primer clarithromycin resistance in patients living in rural area with no history of macrolide use. The prevalence of mutant strains among the macrolide-resistant H. pylori varies even geographically between close provinces.
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Pathogenesis of Helicobacter pylori-Related Gastroduodenal Diseases from Molecular Epidemiological Studies. Gastroenterol Res Pract 2012; 2012:371503. [PMID: 22829807 PMCID: PMC3398592 DOI: 10.1155/2012/371503] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 04/27/2012] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori is a major human pathogen that infects the stomach and produces inflammation that is responsible for various gastroduodenal diseases. Despite the high prevalence of H. pylori infections in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than in other countries. The incidence of gastric cancer also tends to decrease from north to south in East Asia. Data from molecular epidemiological studies show that this variation in different geographic areas could be explained in part by different types of H. pylori virulence factors, especially CagA, VacA, and OipA. H. pylori infection is thought to be involved in both gastric cancer and duodenal ulcer, which are at opposite ends of the disease spectrum. This discrepancy can also be explained in part by another H. pylori factor, DupA, as well as by CagA typing (East Asian type versus Western type). H. pylori has a genome of approximately 1,600 genes; therefore, there might be other novel virulence factors. Because genome wide analyses using whole-genome sequencing technology give a broad view of the genome of H. pylori, we hope that next-generation sequencers will enable us to efficiently investigate novel virulence factors.
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59
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Zhang C, Xu S, Xu D. Risk assessment of gastric cancer caused by Helicobacter pylori using CagA sequence markers. PLoS One 2012; 7:e36844. [PMID: 22615823 PMCID: PMC3352932 DOI: 10.1371/journal.pone.0036844] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 04/11/2012] [Indexed: 02/07/2023] Open
Abstract
Background As a marker of Helicobacter pylori, Cytotoxin-associated gene A (cagA) has been revealed to be the major virulence factor causing gastroduodenal diseases. However, the molecular mechanisms that underlie the development of different gastroduodenal diseases caused by cagA-positive H. pylori infection remain unknown. Current studies are limited to the evaluation of the correlation between diseases and the number of Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs in the CagA strain. To further understand the relationship between CagA sequence and its virulence to gastric cancer, we proposed a systematic entropy-based approach to identify the cancer-related residues in the intervening regions of CagA and employed a supervised machine learning method for cancer and non-cancer cases classification. Methodology An entropy-based calculation was used to detect key residues of CagA intervening sequences as the gastric cancer biomarker. For each residue, both combinatorial entropy and background entropy were calculated, and the entropy difference was used as the criterion for feature residue selection. The feature values were then fed into Support Vector Machines (SVM) with the Radial Basis Function (RBF) kernel, and two parameters were tuned to obtain the optimal F value by using grid search. Two other popular sequence classification methods, the BLAST and HMMER, were also applied to the same data for comparison. Conclusion Our method achieved 76% and 71% classification accuracy for Western and East Asian subtypes, respectively, which performed significantly better than BLAST and HMMER. This research indicates that small variations of amino acids in those important residues might lead to the virulence variance of CagA strains resulting in different gastroduodenal diseases. This study provides not only a useful tool to predict the correlation between the novel CagA strain and diseases, but also a general new framework for detecting biological sequence biomarkers in population studies.
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Affiliation(s)
- Chao Zhang
- Department of Computer Science, University of Missouri, Columbia, Missouri, United States of America
- C.S. Bond Life Science Center, University of Missouri, Columbia, Missouri, United States of America
| | - Shunfu Xu
- C.S. Bond Life Science Center, University of Missouri, Columbia, Missouri, United States of America
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
- * E-mail: (SX); (DX)
| | - Dong Xu
- Department of Computer Science, University of Missouri, Columbia, Missouri, United States of America
- C.S. Bond Life Science Center, University of Missouri, Columbia, Missouri, United States of America
- * E-mail: (SX); (DX)
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60
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Mueller D, Tegtmeyer N, Brandt S, Yamaoka Y, De Poire E, Sgouras D, Wessler S, Torres J, Smolka A, Backert S. c-Src and c-Abl kinases control hierarchic phosphorylation and function of the CagA effector protein in Western and East Asian Helicobacter pylori strains. J Clin Invest 2012; 122:1553-66. [PMID: 22378042 PMCID: PMC3314471 DOI: 10.1172/jci61143] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 01/11/2012] [Indexed: 12/24/2022] Open
Abstract
Many bacterial pathogens inject into host cells effector proteins that are substrates for host tyrosine kinases such as Src and Abl family kinases. Phosphorylated effectors eventually subvert host cell signaling, aiding disease development. In the case of the gastric pathogen Helicobacter pylori, which is a major risk factor for the development of gastric cancer, the only known effector protein injected into host cells is the oncoprotein CagA. Here, we followed the hierarchic tyrosine phosphorylation of H. pylori CagA as a model system to study early effector phosphorylation processes. Translocated CagA is phosphorylated on Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs EPIYA-A, EPIYA-B, and EPIYA-C in Western strains of H. pylori and EPIYA-A, EPIYA-B, and EPIYA-D in East Asian strains. We found that c-Src only phosphorylated EPIYA-C and EPIYA-D, whereas c-Abl phosphorylated EPIYA-A, EPIYA-B, EPIYA-C, and EPIYA-D. Further analysis revealed that CagA molecules were phosphorylated on 1 or 2 EPIYA motifs, but never simultaneously on 3 motifs. Furthermore, none of the phosphorylated EPIYA motifs alone was sufficient for inducing AGS cell scattering and elongation. The preferred combination of phosphorylated EPIYA motifs in Western strains was EPIYA-A and EPIYA-C, either across 2 CagA molecules or simultaneously on 1. Our study thus identifies a tightly regulated hierarchic phosphorylation model for CagA starting at EPIYA-C/D, followed by phosphorylation of EPIYA-A or EPIYA-B. These results provide insight for clinical H. pylori typing and clarify the role of phosphorylated bacterial effector proteins in pathogenesis.
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Affiliation(s)
- Doreen Mueller
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Nicole Tegtmeyer
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sabine Brandt
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yoshio Yamaoka
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Eimear De Poire
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Dionyssios Sgouras
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Silja Wessler
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Javier Torres
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Adam Smolka
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Steffen Backert
- University of Magdeburg, Department of Medical Microbiology, Magdeburg, Germany.
University College Dublin, School of Biomolecular and Biomedical Sciences, Dublin, Ireland.
Michael E. DeBakey Veterans Affairs Medical Center and Baylor College of Medicine, Department Medicine-Gastroenterology, Houston, Texas, USA.
Oita University Faculty of Medicine, Department Environmental and Preventive Medicine, Yufu, Japan.
Hellenic Pasteur Institute, Laboratory of Medical Microbiology, Athens, Greece.
Division of Microbiology, University Salzburg, Salzburg, Austria.
Unidad de Investigacion en Enfermedades Infecciosas, UMAE Pediatria, IMSS, Mexico.
Department of Medicine/Gastroenterology, Medical University of South Carolina, Charleston, South Carolina, USA
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Association between Helicobacter pylori virulence factors and gastroduodenal diseases in Okinawa, Japan. J Clin Microbiol 2011; 50:876-83. [PMID: 22189111 DOI: 10.1128/jcm.05562-11] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The incidence of gastric cancer in Okinawa is lowest in Japan. Some previous reports using small number of strains suggested that the high prevalence of Helicobacter pylori with Western-type cagA in Okinawa compared to other areas in Japan might contribute to the low incidence of gastric cancer. It has still not been confirmed why the prevalence of Western-type cagA strains is high in Okinawa. We examined the association between the virulence factors of H. pylori and gastroduodenal diseases in Okinawa. The genotypes of cagA and vacA of 337 H. pylori strains were determined by PCR and gene sequencing. The genealogy of these Western-type cagA strains in Okinawa was analyzed by multilocus sequence typing (MLST). Overall, 86.4% of the strains possessed cagA: 70.3% were East-Asian type and 16.0% were Western type. After adjustment by age and sex, the presence of East-Asian-type cagA/vacA s1m1 genotypes was significantly associated with gastric cancer compared to gastritis (odds ratio = 6.68, 95% confidence interval = 1.73 to 25.8). The structure of Western-type CagA in Okinawa was different from that of typical Western-type CagA found in Western countries. Intriguingly, MLST analysis revealed that the majority of Western-type cagA strains formed individual clusters but not hpEurope. Overall, low prevalence of gastric cancer in Okinawa may result from the high prevalence of non-East-Asian-type cagA strains. The origin of Western-type cagA strains in Okinawa may be different from those of Western countries.
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Molecular epidemiology, population genetics, and pathogenic role of Helicobacter pylori. INFECTION GENETICS AND EVOLUTION 2011; 12:203-13. [PMID: 22197766 DOI: 10.1016/j.meegid.2011.12.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 12/07/2011] [Accepted: 12/08/2011] [Indexed: 12/17/2022]
Abstract
Helicobacter pylori infection is linked to various gastroduodenal diseases; however, only approximately 20% of infected individuals develop severe diseases. Despite the high prevalence of H. pylori infection in Africa and South Asia, the incidence of gastric cancer in these areas is much lower than in other countries. Furthermore, the incidence of gastric cancer tends to decrease from north to south in East Asia. Such geographic differences in the pathology can be explained, at least in part, by the presence of different types of H. pylori virulence factors, especially cagA, vacA, and the right end of the cag pathogenicity island. The genotype of the virulence genes is also useful as a tool to track human migration utilizing the high genetic diversity and frequent recombination between different H. pylori strains. Multilocus sequence typing (MLST) analysis using seven housekeeping genes can also help to predict the history of human migrations. Population structure analysis based on MLST has revealed seven modern population types of H. pylori, which derived from six ancestral populations. Interestingly, the incidence of gastric cancer is closely related to the distribution of H. pylori populations. The different incidence of gastric cancer can be partly attributed to the different genotypes of H. pylori circulating in different geographic areas. Although approaches by MLST and virulence factors are effective, these methods focus on a small number of genes and may miss information conveyed by the rest of the genome. Genome-wide analyses using DNA microarray or whole-genome sequencing technology give a broad view on the genome of H. pylori. In particular, next-generation sequencers, which can read DNA sequences in less time and at lower costs than Sanger sequencing, enabled us to efficiently investigate not only the evolution of H. pylori, but also novel virulence factors and genomic changes related to drug resistance.
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63
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Role of Abl and Src family kinases in actin-cytoskeletal rearrangements induced by the Helicobacter pylori CagA protein. Eur J Cell Biol 2011; 90:880-90. [DOI: 10.1016/j.ejcb.2010.11.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/12/2010] [Accepted: 11/15/2010] [Indexed: 12/17/2022] Open
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González CA, Agudo A. Carcinogenesis, prevention and early detection of gastric cancer: where we are and where we should go. Int J Cancer 2011; 130:745-53. [PMID: 21918974 DOI: 10.1002/ijc.26430] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 09/01/2011] [Indexed: 12/15/2022]
Abstract
Helicobacter pylori is the most common cause of gastric cancer (GC), though smoking, alcohol, diet, genetics and epigenetic factors may also have a role in the occurrence of the disease. Why H. pylori cause GC in only a minority of those infected remains unknown. Although mechanisms of H. pylori-induced carcinogenesis are not yet well understood, several genotypes of H. pylori have been associated with strain virulence and disease risk. Primary prevention of GC should be addressed by avoiding exposure to factors that increase the risk and to promote factors associated with decrease risk. Vaccines against H. pylori are an ongoing promise and not yet available. Chemoprevention through vitamin supplementation has shown no benefit. Screening and eradication of H. pylori in the general population is not advised. Given that GC is a multiple-steps process, the identification of patients with preneoplastic lesions with high risk of progression, and periodic endoscopic surveillance of them represents the most effective way for early diagnosis of GC. However, clinical guidelines for surveillance are lacking and there are no clear criteria to classify patients into high or low risk of progressing to GC. No study has shown the potential usefulness of combining the information on the type of preneoplastic lesions, genetic and epigenetic, lifestyle and virulence bacterial factors in order to identify high risk patients who need more intensive surveillance. The integration of all this information, in a prediction model requires further research and could be the most important contribution for reducing the burden of GC.
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Affiliation(s)
- Carlos A González
- Unit of Nutrition, Environment and Cancer, Epidemiology Research Programme, Catalan Institut of Oncology, Hospitalet del Llobregat, Barcelona, Spain.
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Furuta Y, Yahara K, Hatakeyama M, Kobayashi I. Evolution of cagA oncogene of Helicobacter pylori through recombination. PLoS One 2011; 6:e23499. [PMID: 21853141 PMCID: PMC3154945 DOI: 10.1371/journal.pone.0023499] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 07/19/2011] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori is a gastric pathogen that infects half the human population and causes gastritis, ulcers, and cancer. The cagA gene product is a major virulence factor associated with gastric cancer. It is injected into epithelial cells, undergoes phosphorylation by host cell kinases, and perturbs host signaling pathways. CagA is known for its geographical, structural, and functional diversity in the C-terminal half, where an EPIYA host-interacting motif is repeated. The Western version of CagA carries the EPIYA segment types A, B, and C, while the East Asian CagA carries types A, B, and D and shows higher virulence. Many structural variants such as duplications and deletions are reported. In this study, we gained insight into the relationships of CagA variants through various modes of recombination, by analyzing all known cagA variants at the DNA sequence level with the single nucleotide resolution. Processes that occurred were: (i) homologous recombination between DNA sequences for CagA multimerization (CM) sequence; (ii) recombination between DNA sequences for the EPIYA motif; and (iii) recombination between short similar DNA sequences. The left half of the EPIYA-D segment characteristic of East Asian CagA was derived from Western type EPIYA, with Amerind type EPIYA as the intermediate, through rearrangements of specific sequences within the gene. Adaptive amino acid changes were detected in the variable region as well as in the conserved region at sites to which no specific function has yet been assigned. Each showed a unique evolutionary distribution. These results clarify recombination-mediated routes of cagA evolution and provide a solid basis for a deeper understanding of its function in pathogenesis.
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Affiliation(s)
- Yoshikazu Furuta
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Minato-ku, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - Koji Yahara
- Graduate School of Medicine, Kurume University, Kurume, Fukuoka, Japan
- Fujitsu Kyushu Systems LTD, Fukuoka, Fukuoka, Japan
| | - Masanori Hatakeyama
- Department of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Ichizo Kobayashi
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Minato-ku, Tokyo, Japan
- Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
- Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Minato-ku, Tokyo, Japan
- * E-mail:
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Breurec S, Michel R, Seck A, Brisse S, Côme D, Dieye FB, Garin B, Huerre M, Mbengue M, Fall C, Sgouras DN, Thiberge JM, Dia D, Raymond J. Clinical relevance of cagA and vacA gene polymorphisms in Helicobacter pylori isolates from Senegalese patients. Clin Microbiol Infect 2011; 18:153-9. [PMID: 21722260 DOI: 10.1111/j.1469-0691.2011.03524.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The molecular epidemiology of Helicobacter pylori in Africa is poorly documented. From January 2007 to December 2008, we investigated 187 patients with gastric symptoms in one of the main tertiary hospitals in Dakar, Senegal. One hundred and seventeen patients were culture-positive for H. pylori. Polymorphisms in vacA and cagA status were investigated by PCR; the 3'-region of cagA was sequenced, and EPIYA motifs were identified. Bacterial heterogeneity within individuals was extensively assessed by using an approach based on vacA and cagA heterogeneity. Fourteen per cent of H. pylori-positive patients displayed evidence of mixed infection, which may affect disease outcome. Patients with multiple vacA alleles were excluded from subsequent analyses. Among the final study population of 105 patients, 29 had gastritis only, 61 had ulcerated lesions, and 15 had suspicion of neoplasia based on endoscopic findings. All cases of suspected neoplasia were histologically confirmed as gastric cancer (GC). The cagA gene was present in 73.3% of isolates. CagA proteins contained zero (3.7%), one (93.9%) or two (2.4%) EPIYA-C segments, and all were western CagA. Most of the isolates possessed presumed high-vacuolization isotypes (s1i1m1 (57.1%) or s1i1m2 (21.9%)). Despite the small number of cases, GC was associated with cagA (p 0.03), two EPIYA-C segments in the C-terminal region of CagA (p 0.03), and the s1 vacA allele (p 0.002). Multiple EPIYA-C segments were less frequent than reported in other countries, possibly contributing to the low incidence of GC in Senegal.
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Affiliation(s)
- S Breurec
- Institut Pasteur, Unité de Biologie Médicale et Environnementale, Dakar, Senegal.
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Shiota S, Matsunari O, Watada M, Yamaoka Y. Serum Helicobacter pylori CagA antibody as a biomarker for gastric cancer in east-Asian countries. Future Microbiol 2011; 5:1885-93. [PMID: 21155667 DOI: 10.2217/fmb.10.135] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
AIMS In east-Asian countries, while almost all Helicobacter pylori strains possess the cytotokine-associated gene A (CagA) gene, serum CagA antibody is not detected in some infected subjects. We aimed to clarify the association between anti-CagA antibody and gastric cancer in east-Asian countries. MATERIALS AND METHODS We performed a meta-analysis of case-control studies with age- and sex-matched controls, which provided raw data in east-Asian countries. RESULTS Ten studies with a total of 4325 patients were identified in the search. Some reports from Japan, Korea and China showed a positive association between the presence of anti-CagA antibody and gastric cancer; however, the results differed in their various backgrounds. The disparate findings appeared to result from the use of different methods or from variations in the antigens used to detect the anti-CagA antibody. CagA seropositivity was associated with an increased risk of developing gastric cancer. CONCLUSION Anti-CagA antibody can be used as a biomarker for gastric cancer even in east-Asian countries.
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Affiliation(s)
- Seiji Shiota
- Department of Environmental & Preventative Medicine, Oita University Faculty of Medicine, Hasama-machi, Yufu-City, Oita, Japan
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Kawai M, Furuta Y, Yahara K, Tsuru T, Oshima K, Handa N, Takahashi N, Yoshida M, Azuma T, Hattori M, Uchiyama I, Kobayashi I. Evolution in an oncogenic bacterial species with extreme genome plasticity: Helicobacter pylori East Asian genomes. BMC Microbiol 2011; 11:104. [PMID: 21575176 PMCID: PMC3120642 DOI: 10.1186/1471-2180-11-104] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 05/16/2011] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The genome of Helicobacter pylori, an oncogenic bacterium in the human stomach, rapidly evolves and shows wide geographical divergence. The high incidence of stomach cancer in East Asia might be related to bacterial genotype. We used newly developed comparative methods to follow the evolution of East Asian H. pylori genomes using 20 complete genome sequences from Japanese, Korean, Amerind, European, and West African strains. RESULTS A phylogenetic tree of concatenated well-defined core genes supported divergence of the East Asian lineage (hspEAsia; Japanese and Korean) from the European lineage ancestor, and then from the Amerind lineage ancestor. Phylogenetic profiling revealed a large difference in the repertoire of outer membrane proteins (including oipA, hopMN, babABC, sabAB and vacA-2) through gene loss, gain, and mutation. All known functions associated with molybdenum, a rare element essential to nearly all organisms that catalyzes two-electron-transfer oxidation-reduction reactions, appeared to be inactivated. Two pathways linking acetyl~CoA and acetate appeared intact in some Japanese strains. Phylogenetic analysis revealed greater divergence between the East Asian (hspEAsia) and the European (hpEurope) genomes in proteins in host interaction, specifically virulence factors (tipα), outer membrane proteins, and lipopolysaccharide synthesis (human Lewis antigen mimicry) enzymes. Divergence was also seen in proteins in electron transfer and translation fidelity (miaA, tilS), a DNA recombinase/exonuclease that recognizes genome identity (addA), and DNA/RNA hybrid nucleases (rnhAB). Positively selected amino acid changes between hspEAsia and hpEurope were mapped to products of cagA, vacA, homC (outer membrane protein), sotB (sugar transport), and a translation fidelity factor (miaA). Large divergence was seen in genes related to antibiotics: frxA (metronidazole resistance), def (peptide deformylase, drug target), and ftsA (actin-like, drug target). CONCLUSIONS These results demonstrate dramatic genome evolution within a species, especially in likely host interaction genes. The East Asian strains appear to differ greatly from the European strains in electron transfer and redox reactions. These findings also suggest a model of adaptive evolution through proteome diversification and selection through modulation of translational fidelity. The results define H. pylori East Asian lineages and provide essential information for understanding their pathogenesis and designing drugs and therapies that target them.
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Affiliation(s)
- Mikihiko Kawai
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
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Hatakeyama M. Anthropological and clinical implications for the structural diversity of the Helicobacter pylori CagA oncoprotein. Cancer Sci 2011; 102:36-43. [PMID: 20942897 PMCID: PMC11159401 DOI: 10.1111/j.1349-7006.2010.01743.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori CagA is the first bacterial oncoprotein to be identified in relation to human cancer. CagA is delivered into gastric epithelial cells through a bacterial type IV secretion system and localizes to the plasma membrane, where it undergoes tyrosine phosphorylation by host cell kinases. Membrane-localized CagA then mimics mammalian scaffold proteins and perturbs a number of host signaling pathways in both tyrosine phosphorylation-dependent and -independent manners, thereby promoting transformation of gastric epithelial cells. Helicobacter pylori CagA is noted for structural diversity in its C-terminal region, with which CagA interacts with numerous host cell proteins. This CagA polymorphism is primarily due to differential combination and alignment of the four distinct EPIYA segments and the two different CagA-multimerization sequences in making the C-terminal region. The structural diversity substantially influences the pathophysiological action of CagA. This review focuses on the molecular basis for the structural polymorphism that determines the degrees of virulence and oncogenic potential of individual CagA. The pylogeographic distribution of differential CagA isoforms is also discussed in the context of human migration history, which may underlie large geographical variations in the incidence of gastric cancer in different parts of the world.
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Affiliation(s)
- Masanori Hatakeyama
- Division of Microbiology, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
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70
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Distinct host species correlate with Anaplasma phagocytophilum ankA gene clusters. J Clin Microbiol 2010; 49:790-6. [PMID: 21177886 DOI: 10.1128/jcm.02051-10] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anaplasma phagocytophilum is a gram-negative, tick-transmitted, obligate intracellular bacterium that elicits acute febrile diseases in humans and domestic animals. In contrast to the United States, human granulocytic anaplasmosis seems to be a rare disease in Europe despite the initial recognition of A. phagocytophilum as the causative agent of tick-borne fever in European sheep and cattle. Considerable strain variation has been suggested to occur within this species, because isolates from humans and animals differed in their pathogenicity for heterologous hosts. In order to explain host preference and epidemiological diversity, molecular characterization of A. phagocytophilum strains has been undertaken. Most often the 16S rRNA gene was used, but it might be not informative enough to delineate distinct genotypes of A. phagocytophilum. Previously, we have shown that A. phagocytophilum strains infecting Ixodes ricinus ticks are highly diverse in their ankA genes. Therefore, we sequenced the 16S rRNA and ankA genes of 194 A. phagocytophilum strains from humans and several animal species. Whereas the phylogenetic analysis using 16S rRNA gene sequences was not meaningful, we showed that distinct host species correlate with A. phagocytophilum ankA gene clusters.
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71
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Kersulyte D, Kalia A, Gilman RH, Mendez M, Herrera P, Cabrera L, Velapatiño B, Balqui J, Paredes Puente de la Vega F, Rodriguez Ulloa CA, Cok J, Hooper CC, Dailide G, Tamma S, Berg DE. Helicobacter pylori from Peruvian amerindians: traces of human migrations in strains from remote Amazon, and genome sequence of an Amerind strain. PLoS One 2010; 5:e15076. [PMID: 21124785 PMCID: PMC2993954 DOI: 10.1371/journal.pone.0015076] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 10/15/2010] [Indexed: 02/06/2023] Open
Abstract
Background The gastric pathogen Helicobacter pylori is extraordinary in its genetic diversity, the differences between strains from well-separated human populations, and the range of diseases that infection promotes. Principal Findings Housekeeping gene sequences from H. pylori from residents of an Amerindian village in the Peruvian Amazon, Shimaa, were related to, but not intermingled with, those from Asia. This suggests descent of Shimaa strains from H. pylori that had infected the people who migrated from Asia into The Americas some 15,000+ years ago. In contrast, European type sequences predominated in strains from Amerindian Lima shantytown residents, but with some 12% Amerindian or East Asian-like admixture, which indicates displacement of ancestral purely Amerindian strains by those of hybrid or European ancestry. The genome of one Shimaa village strain, Shi470, was sequenced completely. Its SNP pattern was more Asian- than European-like genome-wide, indicating a purely Amerind ancestry. Among its unusual features were two cagA virulence genes, each distinct from those known from elsewhere; and a novel allele of gene hp0519, whose encoded protein is postulated to interact with host tissue. More generally, however, the Shi470 genome is similar in gene content and organization to those of strains from industrialized countries. Conclusions Our data indicate that Shimaa village H. pylori descend from Asian strains brought to The Americas many millennia ago; and that Amerind strains are less fit than, and were substantially displaced by, hybrid or European strains in less isolated communities. Genome comparisons of H. pylori from Amerindian and other communities should help elucidate evolutionary forces that have shaped pathogen populations in The Americas and worldwide.
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Affiliation(s)
- Dangeruta Kersulyte
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Awdhesh Kalia
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Robert H. Gilman
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
- Asociacion Benefica PRISMA, Lima, Peru
- Department of International Health, The Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Melissa Mendez
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Phabiola Herrera
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Billie Velapatiño
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Jacqueline Balqui
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | | | - Jaime Cok
- Policlinico Peruano Japones, Lima, Peru
| | - Catherine C. Hooper
- Departemento de Microbiologia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Giedrius Dailide
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sravya Tamma
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Douglas E. Berg
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Departments of Genetics and Medicine, Washington University School of Medicine, St. Louis, Missouri, United States of America
- * E-mail:
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Abstract
Helicobacter pylori plays an essential role in the development of various gastroduodenal diseases; however, only a small proportion of people infected with H. pylori develop these diseases. Some populations that have a high prevalence of H. pylori infection also have a high incidence of gastric cancer (for example, in East Asia), whereas others do not (for example, in Africa and South Asia). Even within East Asia, the incidence of gastric cancer varies (decreasing in the south). H. pylori is a highly heterogeneous bacterium and its virulence varies geographically. Geographic differences in the incidence of gastric cancer can be explained, at least in part, by the presence of different types of H. pylori virulence factor, especially CagA, VacA and OipA. However, it is still unclear why the pathogenicity of H. pylori increased as it migrated from Africa to East Asia during the course of evolution. H. pylori infection is also thought to be involved in the development of duodenal ulcer, which is at the opposite end of the disease spectrum to gastric cancer. This discrepancy can be explained in part by the presence of H. pylori virulence factor DupA. Despite advances in our understanding of the development of H. pylori-related diseases, further work is required to clarify the roles of H. pylori virulence factors.
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Affiliation(s)
- Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Idaigaoka, Hasama-machi, Yufucity, Oita 879-5593, Japan.
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73
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Abstract
Helicobacter pylori plays an essential role in the development of various gastroduodenal diseases; however, only a small proportion of people infected with H. pylori develop these diseases. Some populations that have a high prevalence of H. pylori infection also have a high incidence of gastric cancer (for example, in East Asia), whereas others do not (for example, in Africa and South Asia). Even within East Asia, the incidence of gastric cancer varies (decreasing in the south). H. pylori is a highly heterogeneous bacterium and its virulence varies geographically. Geographic differences in the incidence of gastric cancer can be explained, at least in part, by the presence of different types of H. pylori virulence factor, especially CagA, VacA and OipA. However, it is still unclear why the pathogenicity of H. pylori increased as it migrated from Africa to East Asia during the course of evolution. H. pylori infection is also thought to be involved in the development of duodenal ulcer, which is at the opposite end of the disease spectrum to gastric cancer. This discrepancy can be explained in part by the presence of H. pylori virulence factor DupA. Despite advances in our understanding of the development of H. pylori-related diseases, further work is required to clarify the roles of H. pylori virulence factors.
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Affiliation(s)
- Yoshio Yamaoka
- Department of Environmental and Preventive Medicine, Oita University Faculty of Medicine, Idaigaoka, Hasamamachi, Yufucity, Oita 879-5593, Japan
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Relationship between J-Western CagA subtype and the vacA m2 region of Helicobacter pylori. J Clin Microbiol 2010; 48:3033-4. [PMID: 20519467 DOI: 10.1128/jcm.00983-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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75
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Abstract
Several bacterial pathogens inject virulence proteins into host target cells that are substrates of eukaryotic tyrosine kinases. One of the key examples is the Helicobacter pylori CagA effector protein which is translocated by a type-IV secretion system. Injected CagA becomes tyrosine-phosphorylated on EPIYA sequence motifs by Src and Abl family kinases. CagA then binds to and activates/inactivates multiple signaling proteins in a phosphorylation-dependent and phosphorylation-independent manner. A recent proteomic screen systematically identified eukaryotic binding partners of the EPIYA phosphorylation sites of CagA and similar sites in other bacterial effectors by high-resolution mass spectrometry. Individual phosphorylation sites recruited a surprisingly high number of interaction partners suggesting that each phosphorylation site can interfere with many downstream pathways. We now count 20 reported cellular binding partners of CagA, which represents the highest quantitiy among all yet known virulence-associated effector proteins in the microbial world. This complexity generates a highly remarkable and puzzling scenario. In addition, the first crystal structure of CagA provided us with new information on the function of this important virulence determinant. Here we review the recent advances in characterizing the multiple binding signaling activities of CagA. Injected CagA can act as a 'master key' that evolved the ability to highjack multiple host cell signalling cascades, which include the induction of membrane dynamics, actin-cytoskeletal rearrangements and the disruption of cell-to-cell junctions as well as proliferative, pro-inflammatory and anti-apoptotic nuclear responses. The discovery that different pathogens use this common strategy to subvert host cell functions suggests that more examples will emerge soon.
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