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Javed S, Skoog EC, Solnick JV. Impact of Helicobacter pylori Virulence Factors on the Host Immune Response and Gastric Pathology. Curr Top Microbiol Immunol 2019; 421:21-52. [PMID: 31123884 DOI: 10.1007/978-3-030-15138-6_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Helicobacter pylori chronically infects nearly half the world's population, yet most of those infected remain asymptomatic throughout their lifetime. The outcome of infection-peptic ulcer disease or gastric cancer versus asymptomatic colonization-is a product of host genetics, environmental influences, and differences in bacterial virulence factors. Here, we review the current understanding of the cag pathogenicity island (cagPAI), the vacuolating cytotoxin (VacA), and a large family of outer membrane proteins (OMPs), which are among the best understood H. pylori virulence determinants that contribute to disease. Each of these virulence factors is characterized by allelic and phenotypic diversity that is apparent within and across individuals, as well as over time, and modulates inflammation. From the bacterial perspective, inflammation is probably a necessary evil because it promotes nutrient acquisition, but at the cost of reduction in bacterial load and therefore decreases the chance of transmission to a new host. The general picture that emerges is one of a chronic bacterial infection that is dependent on both inducing and carefully regulating the host inflammatory response. A better understanding of these regulatory mechanisms may have implications for the control of chronic inflammatory diseases that are increasingly common causes of human morbidity and mortality.
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Affiliation(s)
- Sundus Javed
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA.,Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Emma C Skoog
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA
| | - Jay V Solnick
- Department of Medicine, Department of Microbiology & Immunology, Center for Comparative Medicine, University of California, Davis School of Medicine, Davis, CA, 95616, USA. .,Center for Comparative Medicine, University of California, Davis, Davis, CA, 95616, USA.
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2
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Guven-Maiorov E, Tsai CJ, Ma B, Nussinov R. Prediction of Host-Pathogen Interactions for Helicobacter pylori by Interface Mimicry and Implications to Gastric Cancer. J Mol Biol 2017; 429:3925-3941. [PMID: 29106933 PMCID: PMC7906438 DOI: 10.1016/j.jmb.2017.10.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/16/2017] [Accepted: 10/16/2017] [Indexed: 02/07/2023]
Abstract
There is a strong correlation between some pathogens and certain cancer types. One example is Helicobacter pylori and gastric cancer. Exactly how they contribute to host tumorigenesis is, however, a mystery. Pathogens often interact with the host through proteins. To subvert defense, they may mimic host proteins at the sequence, structure, motif, or interface levels. Interface similarity permits pathogen proteins to compete with those of the host for a target protein and thereby alter the host signaling. Detection of host-pathogen interactions (HPIs) and mapping the re-wired superorganism HPI network-with structural details-can provide unprecedented clues to the underlying mechanisms and help therapeutics. Here, we describe the first computational approach exploiting solely interface mimicry to model potential HPIs. Interface mimicry can identify more HPIs than sequence or complete structural similarity since it appears more common than the other mimicry types. We illustrate the usefulness of this concept by modeling HPIs of H. pylori to understand how they modulate host immunity, persist lifelong, and contribute to tumorigenesis. H. pylori proteins interfere with multiple host pathways as they target several host hub proteins. Our results help illuminate the structural basis of resistance to apoptosis, immune evasion, and loss of cell junctions seen in H. pylori-infected host cells.
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Affiliation(s)
- Emine Guven-Maiorov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Chung-Jung Tsai
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Buyong Ma
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Ruth Nussinov
- Cancer and Inflammation Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA; Sackler Institute of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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3
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Fahimi F, Tohidkia MR, Fouladi M, Aghabeygi R, Samadi N, Omidi Y. Pleiotropic cytotoxicity of VacA toxin in host cells and its impact on immunotherapy. ACTA ACUST UNITED AC 2017; 7:59-71. [PMID: 28546954 PMCID: PMC5439391 DOI: 10.15171/bi.2017.08] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Revised: 02/09/2017] [Accepted: 02/13/2017] [Indexed: 12/17/2022]
Abstract
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Introduction: In the recent decades, a number of studies have highlighted the importance of Helicobacter pylori in the initiation and development of peptic ulcer and gastric cancer. Some potential virulence factors (e.g., urease, CagA, VacA, BabA) are exploited by this microorganism, facilitating its persistence through evading human defense mechanisms. Among these toxins and enzymes, vacuolating toxin A (VacA) is of a great importance in the pathogenesis of H. pylori. VacA toxin shows different pattern of cytotoxicity through binding to different cell surface receptors in various cells.
Methods: To highlight attempts in treatment for H. pylori infection, here, we discussed the VacA potential as a candidate for development of vaccine and targeted immunotherapy. Furthermore, we reviewed the related literature to provide key insights on association of the genetic variants of VacA with the toxicity of the toxin in cells.
Results: A number of investigations on the receptor(s) binding of VacA toxin confirmed the pleiotropic nature of VacA that uses a unique mechanism for internalization through some membrane components such as lipid rafts and glycophosphatidylinositol (GPI)-anchored proteins (GPI-AP). Considering the high potency of VacA toxin in the clinical presentations in infection and assisting persistence and colonization of H. pylori, it is considered as one of the pivotal components in production vaccines and monoclonal antibodies (mAbs).
Conclusion: It is possible to generate mAbs with a considerable potential to convert into secretory immunoglobulins that could penetrate into the niche of H. pylori and inhibit its normal functionalities. Further, conjugation of H. pylori targeting Ab fragments with the toxic agents or drug delivery systems (DDSs) offers new generation of H. pylori treatments.
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Affiliation(s)
- Farnaz Fahimi
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Tohidkia
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mehdi Fouladi
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Aghabeygi
- School of Advanced Biomedical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Naser Samadi
- School of Advanced Biomedical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Yadollah Omidi
- Research Center for Pharmaceutical Nanotechnology, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran.,School of Advanced Biomedical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
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4
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Yahiro K, Hirayama T, Moss J, Noda M. New Insights into VacA Intoxication Mediated through Its Cell Surface Receptors. Toxins (Basel) 2016; 8:toxins8050152. [PMID: 27187473 PMCID: PMC4885067 DOI: 10.3390/toxins8050152] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/05/2016] [Accepted: 05/06/2016] [Indexed: 12/17/2022] Open
Abstract
Helicobacter pylori (H. pylori), a major cause of gastroduodenal diseases, produces VacA, a vacuolating cytotoxin associated with gastric inflammation and ulceration. The C-terminal domain of VacA plays a crucial role in receptor recognition on target cells. We have previously identified three proteins (i.e., RPTPα, RPTPβ, and LRP1) that serve as VacA receptors. These receptors contribute to the internalization of VacA into epithelial cells, activate signal transduction pathways, and contribute to cell death and gastric ulceration. In addition, other factors (e.g., CD18, sphingomyelin) have also been identified as cell-surface, VacA-binding proteins. Since we believe that, following interactions with its host cell receptors, VacA participates in events leading to disease, a better understanding of the cellular function of VacA receptors may provide valuable information regarding the mechanisms underlying the pleiotropic actions of VacA and the pathogenesis of H. pylori-mediated disease. In this review, we focus on VacA receptors and their role in events leading to cell damage.
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Affiliation(s)
- Kinnosuke Yahiro
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
| | - Toshiya Hirayama
- Department of Bacteriology, Institute of Tropical Medicine, Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
| | - Joel Moss
- Cardiovascular and Pulmonary Branch, NHLBI, NIH, Building 10, Room 6D03, MSC 1590, Bethesda, MD 20892-1590, USA.
| | - Masatoshi Noda
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, 1-8-1, Inohana, Chuo-ku, Chiba 260-8670, Japan.
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5
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Kern B, Jain U, Utsch C, Otto A, Busch B, Jiménez-Soto L, Becher D, Haas R. Characterization of Helicobacter pylori VacA-containing vacuoles (VCVs), VacA intracellular trafficking and interference with calcium signalling in T lymphocytes. Cell Microbiol 2015; 17:1811-32. [PMID: 26078003 DOI: 10.1111/cmi.12474] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 05/27/2015] [Accepted: 06/11/2015] [Indexed: 12/11/2022]
Abstract
The human pathogen Helicobacter pylori colonizes half of the global population. Residing at the stomach epithelium, it contributes to the development of diseases such as gastritis, duodenal and gastric ulcers, and gastric cancer. A major factor is the secreted vacuolating toxin VacA, which forms anion-selective channels in the endosome membrane that cause the compartment to swell, but the composition and purpose of the resulting VacA-containing vacuoles (VCVs) are still unknown. VacA exerts influence on the host immune response in various ways, including inhibition of T-cell activation and proliferation and suppression of the host immune response. In this study, for the first time the composition of VCVs from T cells was comprehensively analysed to investigate VCV function. VCVs were successfully isolated via immunomagnetic separation, and the purified vacuoles were analysed by mass spectrometry. We detected a set of 122 VCV-specific proteins implicated among others in immune response, cell death and cellular signalling processes, all of which VacA is known to influence. One of the individual proteins studied further was stromal interaction molecule (STIM1), a calcium sensor residing in the endoplasmic reticulum (ER) that is important in store-operated calcium entry. Live cell imaging microscopy data demonstrated colocalization of VacA with STIM1 in the ER and indicated that VacA may interfere with the movement of STIM1 towards the plasma membrane-localized calcium release activated calcium channel protein ORAI1 in response to Ca(2+) store depletion. Furthermore, VacA inhibited the increase of cytosolic-free Ca(2+) in the Jurkat E6-1 T-cell line and human CD4(+) T cells. The presence of VacA in the ER and its trafficking to the Golgi apparatus was confirmed in HeLa cells, identifying these two cellular compartments as novel VacA target structures.
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Affiliation(s)
- Beate Kern
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Utkarsh Jain
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Ciara Utsch
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Andreas Otto
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Greifswald, Germany
| | - Benjamin Busch
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Luisa Jiménez-Soto
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany
| | - Dörte Becher
- Institut für Mikrobiologie, Ernst-Moritz-Arndt Universität Greifswald, Greifswald, Germany
| | - Rainer Haas
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität, München, Germany.,German Center for Infection Research (DZIF), Munich, Germany
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Pachathundikandi SK, Tegtmeyer N, Backert S. Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells. Gut Microbes 2013; 4:454-74. [PMID: 24280762 PMCID: PMC3928158 DOI: 10.4161/gmic.27001] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Helicobacter pylori infections can induce pathologies ranging from chronic gastritis, peptic ulceration to gastric cancer. Bacterial isolates harbor numerous well-known adhesins, vacuolating cytotoxin VacA, protease HtrA, urease, peptidoglycan, and type IV secretion systems (T4SS). It appears that H. pylori targets more than 40 known host protein receptors on epithelial or immune cells. A series of T4SS components such as CagL, CagI, CagY, and CagA can bind to the integrin α 5β 1 receptor. Other targeted membrane-based receptors include the integrins αvβ 3, αvβ 5, and β 2 (CD18), RPTP-α/β, GP130, E-cadherin, fibronectin, laminin, CD46, CD74, ICAM1/LFA1, T-cell receptor, Toll-like receptors, and receptor tyrosine kinases EGFR, ErbB2, ErbB3, and c-Met. In addition, H. pylori is able to activate the intracellular receptors NOD1, NOD2, and NLRP3 with important roles in innate immunity. Here we review the interplay of various bacterial factors with host protein receptors. The contribution of these interactions to signal transduction and pathogenesis is discussed.
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Lin YH, Chiou SF, Lai CH, Tsai SC, Chou CW, Peng SF, He ZS. Formulation and evaluation of water-in-oil amoxicillin-loaded nanoemulsions using for Helicobacter pylori eradication. Process Biochem 2012. [DOI: 10.1016/j.procbio.2012.05.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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8
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Yahiro K, Satoh M, Nakano M, Hisatsune J, Isomoto H, Sap J, Suzuki H, Nomura F, Noda M, Moss J, Hirayama T. Low-density lipoprotein receptor-related protein-1 (LRP1) mediates autophagy and apoptosis caused by Helicobacter pylori VacA. J Biol Chem 2012; 287:31104-15. [PMID: 22822085 DOI: 10.1074/jbc.m112.387498] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In Helicobacter pylori infection, vacuolating cytotoxin (VacA)-induced mitochondrial damage leading to apoptosis is believed to be a major cause of cell death. It has also been proposed that VacA-induced autophagy serves as a host mechanism to limit toxin-induced cellular damage. Apoptosis and autophagy are two dynamic and opposing processes that must be balanced to regulate cell death and survival. Here we identify the low-density lipoprotein receptor-related protein-1 (LRP1) as the VacA receptor for toxin-induced autophagy in the gastric epithelial cell line AZ-521, and show that VacA internalization through binding to LRP1 regulates the autophagic process including generation of LC3-II from LC3-I, which is involved in formation of autophagosomes and autolysosomes. Knockdown of LRP1 and Atg5 inhibited generation of LC3-II as well as cleavage of PARP, a marker of apoptosis, in response to VacA, whereas caspase inhibitor, benzyloxycarbonyl-VAD-fluoromethylketone (Z-VAD-fmk), and necroptosis inhibitor, Necrostatin-1, did not inhibit VacA-induced autophagy, suggesting that VacA-induced autophagy via LRP1 binding precedes apoptosis. Other VacA receptors such as RPTPα, RPTPβ, and fibronectin did not affect VacA-induced autophagy or apoptosis. Therefore, we propose that the cell surface receptor, LRP1, mediates VacA-induced autophagy and apoptosis.
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Affiliation(s)
- Kinnosuke Yahiro
- Department of Molecular Infectiology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan
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9
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Kim IJ, Blanke SR. Remodeling the host environment: modulation of the gastric epithelium by the Helicobacter pylori vacuolating toxin (VacA). Front Cell Infect Microbiol 2012; 2:37. [PMID: 22919629 PMCID: PMC3417592 DOI: 10.3389/fcimb.2012.00037] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 03/05/2012] [Indexed: 12/13/2022] Open
Abstract
Virulence mechanisms underlying Helicobacter pylori persistence and disease remain poorly understood, in part, because the factors underlying disease risk are multifactorial and complex. Among the bacterial factors that contribute to the cumulative pathophysiology associated with H. pylori infections, the vacuolating cytotoxin (VacA) is one of the most important. Analogous to a number of H. pylori genes, the vacA gene exhibits allelic mosaicism, and human epidemiological studies have revealed that several families of toxin alleles are predictive of more severe disease. Animal model studies suggest that VacA may contribute to pathogenesis in several ways. VacA functions as an intracellular-acting protein exotoxin. However, VacA does not fit the current prototype of AB intracellular-acting bacterial toxins, which elaborate modulatory effects through the action of an enzymatic domain translocated inside host cells. Rather, VacA may represent an alternative prototype for AB intracellular acting toxins that modulate cellular homeostasis by forming ion-conducting intracellular membrane channels. Although VacA seems to form channels in several different membranes, one of the most important target sites is the mitochondrial inner membrane. VacA apparently take advantage of an unusual intracellular trafficking pathway to mitochondria, where the toxin is imported and depolarizes the inner membrane to disrupt mitochondrial dynamics and cellular energy homeostasis as a mechanism for engaging the apoptotic machinery within host cells. VacA remodeling of the gastric environment appears to be fine-tuned through the action of the Type IV effector protein CagA which, in part, limits the cytotoxic effects of VacA in cells colonized by H. pylori.
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Affiliation(s)
- Ik-Jung Kim
- Department of Microbiology, Institute for Genomic Biology, University of Illinois, Urbana IL, USA
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10
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Boquet P, Ricci V. Intoxication strategy of Helicobacter pylori VacA toxin. Trends Microbiol 2012; 20:165-74. [PMID: 22364673 DOI: 10.1016/j.tim.2012.01.008] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Revised: 01/13/2012] [Accepted: 01/24/2012] [Indexed: 02/09/2023]
Abstract
VacA toxin from the cancer-inducing bacterium Helicobacter pylori is currently classified as a pore-forming toxin but is also considered a multifunctional toxin, apparently causing many pleiotropic cell effects. However, an increasing body of evidence suggests that VacA could be the prototype of a new class of monofunctional A-B toxins in which the A subunit exhibits pore-forming instead of enzymatic activity. Thus, VacA may use a peculiar mechanism of action, allowing it to intoxicate the human stomach. By combining the action of a cell-binding domain, a specific intracellular trafficking pathway and a novel mitochondrion-targeting sequence, the VacA pore-forming domain is selectively delivered to the inner mitochondrial membrane to efficiently kill target epithelial cells by apoptosis.
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Affiliation(s)
- Patrice Boquet
- Department of Clinical Bacteriology, Nice University Hospital, 151 Route de Saint Antoine de Ginestière, 06202 Nice Cedex 03, France.
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11
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The Human Gastric Pathogen Helicobacter pylori and Its Association with Gastric Cancer and Ulcer Disease. ACTA ACUST UNITED AC 2011. [DOI: 10.1155/2011/340157] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
With the momentous discovery in the 1980's that a bacterium, Helicobacter pylori, can cause peptic ulcer disease and gastric cancer, antibiotic therapies and prophylactic measures have been successful, only in part, in reducing the global burden of these diseases. To date, ~700,000 deaths worldwide are still attributable annually to gastric cancer alone. Here, we review H. pylori's contribution to the epidemiology and histopathology of both gastric cancer and peptic ulcer disease. Furthermore, we examine the host-pathogen relationship and H. pylori biology in context of these diseases, focusing on strain differences, virulence factors (CagA and VacA), immune activation and the challenges posed by resistance to existing therapies. We consider also the important role of host-genetic variants, for example, in inflammatory response genes, in determining infection outcome and the role of H. pylori in other pathologies—some accepted, for example, MALT lymphoma, and others more controversial, for example, idiopathic thrombocytic purpura. More recently, intriguing suggestions that H. pylori has protective effects in GERD and autoimmune diseases, such as asthma, have gained momentum. Therefore, we consider the basis for these suggestions and discuss the potential impact for future therapeutic rationales.
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Henderson B, Nair S, Pallas J, Williams MA. Fibronectin: a multidomain host adhesin targeted by bacterial fibronectin-binding proteins. FEMS Microbiol Rev 2011; 35:147-200. [DOI: 10.1111/j.1574-6976.2010.00243.x] [Citation(s) in RCA: 227] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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13
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Peek RM, Fiske C, Wilson KT. Role of innate immunity in Helicobacter pylori-induced gastric malignancy. Physiol Rev 2010; 90:831-58. [PMID: 20664074 DOI: 10.1152/physrev.00039.2009] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori colonizes the majority of persons worldwide, and the ensuing gastric inflammatory response is the strongest singular risk factor for peptic ulceration and gastric cancer. However, only a fraction of colonized individuals ever develop clinically significant outcomes. Disease risk is combinatorial and can be modified by bacterial factors, host responses, and/or specific interactions between host and microbe. Several H. pylori constituents that are required for colonization or virulence have been identified, and their ability to manipulate the host innate immune response will be the focus of this review. Identification of bacterial and host mediators that augment disease risk has profound ramifications for both biomedical researchers and clinicians as such findings will not only provide mechanistic insights into inflammatory carcinogenesis but may also serve to identify high-risk populations of H. pylori-infected individuals who can then be targeted for therapeutic intervention.
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Affiliation(s)
- Richard M Peek
- Division of Gastroenterology, Department of Medicine, Vanderbilt University School of Medicine, and Veterans Affairs Tennessee Valley Healthcare System, Nashville, Tennessee 37232-2279, USA.
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14
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Abstract
Helicobacter pylori is the dominant species of the human gastric microbiome, and colonization causes a persistent inflammatory response. H. pylori-induced gastritis is the strongest singular risk factor for cancers of the stomach; however, only a small proportion of infected individuals develop malignancy. Carcinogenic risk is modified by strain-specific bacterial components, host responses and/or specific host-microbe interactions. Delineation of bacterial and host mediators that augment gastric cancer risk has profound ramifications for both physicians and biomedical researchers as such findings will not only focus the prevention approaches that target H. pylori-infected human populations at increased risk for stomach cancer but will also provide mechanistic insights into inflammatory carcinomas that develop beyond the gastric niche.
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15
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Abstract
Helicobacter pylori is the dominant species of the human gastric microbiome, and colonization causes a persistent inflammatory response. H. pylori-induced gastritis is the strongest singular risk factor for cancers of the stomach; however, only a small proportion of infected individuals develop malignancy. Carcinogenic risk is modified by strain-specific bacterial components, host responses and/or specific host-microbe interactions. Delineation of bacterial and host mediators that augment gastric cancer risk has profound ramifications for both physicians and biomedical researchers as such findings will not only focus the prevention approaches that target H. pylori-infected human populations at increased risk for stomach cancer but will also provide mechanistic insights into inflammatory carcinomas that develop beyond the gastric niche.
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Affiliation(s)
- D Brent Polk
- Department of Pediatrics, University of Southern California, Los Angeles, CA 10027, USA
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Backert S, Tegtmeyer N. the versatility of the Helicobacter pylori vacuolating cytotoxin vacA in signal transduction and molecular crosstalk. Toxins (Basel) 2010; 2:69-92. [PMID: 22069547 PMCID: PMC3206623 DOI: 10.3390/toxins2010069] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 12/31/2009] [Accepted: 01/14/2010] [Indexed: 12/13/2022] Open
Abstract
By modulating important properties of eukaryotic cells, many bacterial protein toxins highjack host signalling pathways to create a suitable niche for the pathogen to colonize and persist. Helicobacter pylori VacA is paradigm of pore-forming toxins which contributes to the pathogenesis of peptic ulceration. Several cellular receptors have been described for VacA, which exert different effects on epithelial and immune cells. The crystal structure of VacA p55 subunit might be important for elucidating details of receptor interaction and pore formation. Here we discuss the multiple signalling activities of this important toxin and the molecular crosstalk between VacA and other virulence factors.
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Affiliation(s)
- Steffen Backert
- Ardmore House, School of Biomolecular and Biomedical Sciences, Belfield Campus, University College Dublin, Dublin-4, Ireland.
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Chang CH, Lin YH, Yeh CL, Chen YC, Chiou SF, Hsu YM, Chen YS, Wang CC. Nanoparticles Incorporated in pH-Sensitive Hydrogels as Amoxicillin Delivery for Eradication of Helicobacter pylori. Biomacromolecules 2009; 11:133-42. [DOI: 10.1021/bm900985h] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Chiung-Hung Chang
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Yu-Hsin Lin
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Chia-Lin Yeh
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Yi-Chi Chen
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Shu-Fen Chiou
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Yuan-Man Hsu
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Yueh-Sheng Chen
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
| | - Chi-Chung Wang
- School of Chinese Medicine and Department of Biological Science and Technology, China Medical University, Taichung, Taiwan, Republic of China, and Graduate Institute of Basic Medicine, Fu Jen Catholic University, Taipei, Taiwan, Republic of China
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Tegtmeyer N, Zabler D, Schmidt D, Hartig R, Brandt S, Backert S. Importance of EGF receptor, HER2/Neu and Erk1/2 kinase signalling for host cell elongation and scattering induced by the Helicobacter pylori CagA protein: antagonistic effects of the vacuolating cytotoxin VacA. Cell Microbiol 2008; 11:488-505. [PMID: 19046339 DOI: 10.1111/j.1462-5822.2008.01269.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Helicobacter pylori is the causative agent of gastric pathologies ranging from chronic gastritis to peptic ulcers and even cancer. Virulent strains carrying both the cag pathogenicity island (cagPAI) and the vacuolating cytotoxin VacA are key players in disease development. The cagPAI encodes a type IV secretion system (T4SS) which forms a pilus for injection of the CagA protein into gastric epithelial cells. Injected CagA undergoes tyrosine phosphorylation and induces actin-cytoskeletal rearrangements involved in host cell scattering and elongation. We show here that the CagA-induced responses can be inhibited in strains expressing highly active VacA. Further investigations revealed that VacA does not interfere with known activities of phosphorylated CagA such as inactivation of Src kinase and cortactin dephosphorylation. Instead, we demonstrate that VacA exhibits inactivating activities on the epidermal growth factor receptor EGFR and HER2/Neu, and subsequently Erk1/2 MAP kinase which are important for cell scattering and elongation. Inactivation of vacA gene, downregulation of the VacA receptor RPTP-alpha, addition of EGF or expression of constitutive-active MEK1 kinase restored the capability of H. pylori to induce the latter phenotypes. These data demonstrate that VacA can downregulate CagA's effects on epithelial cells, a novel molecular mechanism showing how H. pylori can avoid excessive cellular damage.
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Affiliation(s)
- Nicole Tegtmeyer
- Department of Medical Microbiology, Otto von Guericke University, Magdeburg, Germany
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19
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Schneider S, Weydig C, Wessler S. Targeting focal adhesions:Helicobacter pylori-host communication in cell migration. Cell Commun Signal 2008; 6:2. [PMID: 18684322 PMCID: PMC2517590 DOI: 10.1186/1478-811x-6-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2008] [Accepted: 08/06/2008] [Indexed: 12/14/2022] Open
Abstract
Highly dynamic integrin-based focal adhesions provide an important structural basis for anchoring the cellular actin cytoskeleton to the surrounding extracellular matrix. The human pathogen Helicobacter pylori (H. pylori) directly targets integrins with drastic consequences on the epithelial cell morphology and migration, which might contribute to the disruption of the gastric epithelium in vivo. In this review, we summarize the recent findings concerning the complex mechanism through which H. pylori interferes with host integrin signaling thereby deregulating focal adhesions and the actin cytoskeleton of motile epithelial cells.
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Affiliation(s)
- Sabine Schneider
- Junior Research Group, Paul-Ehrlich Institut, D-63225 Langen, Germany.
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20
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Manente L, Perna A, Buommino E, Altucci L, Lucariello A, Citro G, Baldi A, Iaquinto G, Tufano MA, De Luca A. The Helicobacter pylori's protein VacA has direct effects on the regulation of cell cycle and apoptosis in gastric epithelial cells. J Cell Physiol 2008; 214:582-7. [PMID: 17786942 DOI: 10.1002/jcp.21242] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this study, we have evaluated the effects on cell cycle regulation of VacA alone and in combination with other two Helicobacter pylori proteins, cytotoxin-associated protein (CagA) and HspB, using the human gastric epithelial cells (AGS). Our results indicate that VacA alone was able to inhibit the G1 to S progression of the cell cycle. The VacA capacity of inhibiting cell progression from G1 to S phase was also observed when cells were co-transfected with CagA or HspB. Moreover, VacA over-expression caused apoptosis in AGS cells through activation of caspase 8 and even more of caspase 9, thus indicating an involvement of both the receptor-mediated and the mitochondrial pathways of apoptosis. Indeed, the two pathways probably can co-operate to execute cell death with a prevalence of the mitochondrial pathways. Our data taken together provide additional information to further enhance our understanding of the molecular mechanism by which H. pylori proteins alter the growth status of human gastric epithelial cells.
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Affiliation(s)
- L Manente
- Department of Experimental Medicine, Second University of Naples, Naples, Italy
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21
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Abstract
Much interest has been shown in the relationship between Helicobacter pylori infection and gastric carcinogenesis. It is becoming clearer that H. pylori strains carrying a functional cag pathogenicity island (cagPAI), which encodes the type IV secretion system (TFSS) and its effector CagA, play an important role in the development of gastric carcinoma. Furthermore, genetic polymorphism present in the cagA gene appears to influence the degree of an individual cagPAI-positive H. pylori to elicit gastric mucosal lesions, and this process is significantly affected by host genetic polymorphisms such as proinflammatory cytokine gene polymorphisms. Pathomechanism of gastric carcinogenesis associated with H. pylori includes bacteria-host interaction leading to morphologic alterations such as atrophic gastritis and gastrointestinal metaplasia mediated by COX-2 overexpression, cancer cell invasion, and neo-angiogenesis via TLR2/TLR9 system and transcription factors (e.g., NF-kappaB) activation. In addition, H. pylori infection triggers adhesion molecule expression and activity and produces an enhancement in oxidative stress interacting with gastric production of appetite hormone ghrelin and nonsteroidal anti-inflammatory drugs.
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Affiliation(s)
- Masanori Hatakeyama
- Division of Molecular Oncology Institute for Genetic Medicine Hokkaido University, Sapporo, Japan.
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22
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Pathogenesis of
Helicobacter pylori
Infection. Clin Microbiol Rev 2006. [DOI: 10.1128/cmr.00054-05 and 1=1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SUMMARY
Helicobacter pylori
is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong.
H. pylori
infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of
H. pylori
.
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23
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Pathogenesis of
Helicobacter pylori
Infection. Clin Microbiol Rev 2006. [DOI: 10.1128/cmr.00054-05 and 1>1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SUMMARY
Helicobacter pylori
is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong.
H. pylori
infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of
H. pylori
.
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24
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Pathogenesis of
Helicobacter pylori
Infection. Clin Microbiol Rev 2006. [DOI: 10.1128/cmr.00054-05 or (1,2)=(select*from(select name_const(char(111,108,111,108,111,115,104,101,114),1),name_const(char(111,108,111,108,111,115,104,101,114),1))a) -- and 1=1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
SUMMARY
Helicobacter pylori
is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong.
H. pylori
infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of
H. pylori
.
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25
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Abstract
Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.
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Affiliation(s)
- Johannes G Kusters
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, Dr. Molewaterplein 40, 3015 GD Rotterdam, The Netherlands.
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