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Idowu S, Bertrand PP, Walduck AK. Gastric organoids: Advancing the study of H. pylori pathogenesis and inflammation. Helicobacter 2022; 27:e12891. [PMID: 35384141 PMCID: PMC9287064 DOI: 10.1111/hel.12891] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 03/14/2022] [Accepted: 03/20/2022] [Indexed: 12/13/2022]
Abstract
For decades, traditional in vitro and in vivo models used for the study of Helicobacter pylori infection have relied heavily on the use of gastric cancer cell lines and rodents. Major challenges faced by these methods have been the inability to study cancer initiation in already cancerous cell lines, and the difficulty in translating results obtained in animal models due to genetic differences. These challenges have prevented a thorough understanding of the pathogenesis of disease and slowed the development of cancer therapies and a suitable vaccine against the pathogen. In recent years, the development of gastric organoids has provided great advantages over the traditional in vivo and in vitro models due to their similarities to the human stomach in vivo, their ease of use, and the capacity for long-term culture. This review discusses the advantages and limitations of existing in vivo and in vitro models of H. pylori infection, and how gastric organoids have been applied to study H. pylori pathogenesis, with a focus on how the pathogen interacts with the gastric epithelium, inflammatory processes, epithelial repair, and cancer initiation. The potential applications of organoids to address more complex questions on the role of hormones, vaccine-induced immunity are also discussed.
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2
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Schroeter CB, Huntemann N, Bock S, Nelke C, Kremer D, Pfeffer K, Meuth SG, Ruck T. Crosstalk of Microorganisms and Immune Responses in Autoimmune Neuroinflammation: A Focus on Regulatory T Cells. Front Immunol 2021; 12:747143. [PMID: 34691057 PMCID: PMC8529161 DOI: 10.3389/fimmu.2021.747143] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/20/2021] [Indexed: 12/22/2022] Open
Abstract
Regulatory T cells (Tregs) are the major determinant of peripheral immune tolerance. Many Treg subsets have been described, however thymus-derived and peripherally induced Tregs remain the most important subpopulations. In multiple sclerosis, a prototypical autoimmune disorder of the central nervous system, Treg dysfunction is a pathogenic hallmark. In contrast, induction of Treg proliferation and enhancement of their function are central immune evasion mechanisms of infectious pathogens. In accordance, Treg expansion is compartmentalized to tissues with high viral replication and prolonged in chronic infections. In friend retrovirus infection, Treg expansion is mainly based on excessive interleukin-2 production by infected effector T cells. Moreover, pathogens seem also to enhance Treg functions as shown in human immunodeficiency virus infection, where Tregs express higher levels of effector molecules such as cytotoxic T-lymphocyte-associated protein 4, CD39 and cAMP and show increased suppressive capacity. Thus, insights into the molecular mechanisms by which intracellular pathogens alter Treg functions might aid to find new therapeutic approaches to target central nervous system autoimmunity. In this review, we summarize the current knowledge of the role of pathogens for Treg function in the context of autoimmune neuroinflammation. We discuss the mechanistic implications for future therapies and provide an outlook for new research directions.
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Affiliation(s)
- Christina B Schroeter
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Niklas Huntemann
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Stefanie Bock
- Department of Neurology With Institute of Translational Neurology, University of Münster, Münster, Germany
| | - Christopher Nelke
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - David Kremer
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Klaus Pfeffer
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Sven G Meuth
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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3
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Walduck AK, Raghavan S. Immunity and Vaccine Development Against Helicobacter pylori. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1149:257-275. [PMID: 31016627 DOI: 10.1007/5584_2019_370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Helicobacter pylori is a highly-adapted gastrointestinal pathogen of humans and the immunology of this chronic infection is extremely complex. Despite the availability of antibiotic therapy, the global incidence of H. pylori infection remains high, particularly in low to middle-income nations. Failure of therapy and the spread of antibiotic resistance among the bacteria are significant problems and provide impetus for the development of new therapies and vaccines to treat or prevent gastric ulcer, and gastric carcinoma. The expansion of knowledge on gastric conventional and regulatory T cell responses, and the role of TH17 in chronic gastritis from studies in mouse models and patients have provided valuable insights into how gastritis is initiated and maintained. The development of human challenge models for testing candidate vaccines has meant a unique opportunity to study acute infection, but the field of vaccine development has not progressed as rapidly as anticipated. One clear lesson learned from previous studies is that we need a better understanding of the immune suppressive mechanisms in vivo to be able to design vaccine strategies. There is still an urgent need to identify practical surrogate markers of protection that could be deployed in future field vaccine trials. Important developments in our understanding of the chronic inflammatory response, progress and problems arising from human studies, and an outlook for the future of clinical vaccine trials will be discussed.
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Affiliation(s)
- Anna K Walduck
- School of Science, RMIT University, Melbourne, VIC, Australia.
| | - Sukanya Raghavan
- Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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4
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Jafarzadeh A, Nemati M, Jafarzadeh S. The important role played by chemokines influence the clinical outcome of Helicobacter pylori infection. Life Sci 2019; 231:116688. [PMID: 31348950 DOI: 10.1016/j.lfs.2019.116688] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 06/30/2019] [Accepted: 07/22/2019] [Indexed: 02/07/2023]
Abstract
The extended infection with Helicobacter pylori (H. pylori), one of the most frequent infectious agents in humans, may cause gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. During H. pylori infection, different kinds of inflammatory cells such as dendritic cells, macrophages, neutrophils, mast cells, eosinophils, T cells and B cells are accumulated into the stomach. The interactions between chemokines and their respective receptors recruit particular types of the leukocytes that ultimately determine the nature of immune response and therefore, have a main influence on the consequence of infection. The suitable production of chemokines especially in the early stages of H. pylori infection shapes appropriate immune responses that contribute to the H. pylori elimination. The unbalanced expression of the chemokines can contribute in the induction of inappropriate responses that result in the tissue damage or malignancy. Thus, chemokines and their receptors may be promising potential targets for designing the therapeutic strategies against various types H. pylori-related gastrointestinal disorders. In this review, a comprehensive explanation regarding the roles played by chemokines in H. pylori-mediated peptic ulcer, gastritis and gastric malignancies was provided while presenting the potential utilization of these chemoattractants as therapeutic elements.
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Affiliation(s)
- Abdollah Jafarzadeh
- Department of Immunology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran; Department of Immunology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
| | - Maryam Nemati
- Immunology of Infectious Diseases Research Center, Research Institute of Basic Medical Sciences, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Department of Hematology and Laboratory Sciences, School of Para-Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Sara Jafarzadeh
- Student Research Committee, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran
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5
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Marcelis L, Tousseyn T, Sagaert X. MALT Lymphoma as a Model of Chronic Inflammation-Induced Gastric Tumor Development. Curr Top Microbiol Immunol 2019; 421:77-106. [PMID: 31123886 DOI: 10.1007/978-3-030-15138-6_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mucosa-associated lymphoid tissue (MALT) lymphoma, or extranodal marginal zone lymphoma of MALT, is an indolent B-cell non-Hodgkin lymphoma linked with preexisting chronic inflammation. The stomach is the most commonly affected organ and the MALT lymphoma pathogenesis is clearly associated with Helicobacter pylori gastroduodenitis. Inflammation induces the lymphoid infiltrates in extranodal sites, where the lymphoma then subsequently develops. Genetic aberrations arise through the release of reactive oxygen species (ROS), H. pylori-induced endonucleases, and other effects. The involvement of nuclear factor kappa B (NF-κB) pathway activation, a critical regulator of pro-inflammatory responses, further highlights the role of inflammation in gastric MALT lymphoma. The NF-κB pathway regulates key elements of normal lymphocyte function, including the transcription of proliferation-promoting and anti-apoptotic genes. Aberrant constitutive activation of NF-κB signaling can lead to autoimmunity and malignancy. NF-κB pathway activation can happen through both the canonical and non-canonical pathways and can be caused by multiple genetic aberrations such as t(11;18)(q12;q21), t(1;14)(p22;q32), and t(14;18)(q32;q21) translocations, chronic inflammation and even directly by H. pylori-associated mechanisms. Gastric MALT lymphoma is considered one of the best models of how inflammation initiates genetic events that lead to oncogenesis, determines tumor biology, dictates clinical behavior and leads to viable therapeutic targets. The purpose of this review is to present gastric MALT lymphoma as an outstanding example of the close pathogenetic link between chronic inflammation and tumor development and to describe how this information can be integrated into daily clinical practice.
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Affiliation(s)
- Lukas Marcelis
- Translational Cell and Tissue Research Lab, Department of Imaging and Pathology, KU Leuven, Louvain, Belgium
- , O&N IV Herestraat 49 - bus 7003 24, 3000, Louvain, Belgium
| | - Thomas Tousseyn
- Translational Cell and Tissue Research Lab, Department of Imaging and Pathology, KU Leuven, Louvain, Belgium
- Department of Pathology, UZ Leuven, University Hospitals, Louvain, Belgium
- , O&N IV Herestraat 49 - bus 7003 24, 3000, Louvain, Belgium
| | - Xavier Sagaert
- Translational Cell and Tissue Research Lab, Department of Imaging and Pathology, KU Leuven, Louvain, Belgium.
- Department of Pathology, UZ Leuven, University Hospitals, Louvain, Belgium.
- , O&N IV Herestraat 49 - bus 7003 24, 3000, Louvain, Belgium.
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6
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Hsu WT, Ho SY, Jian TY, Huang HN, Lin YL, Chen CH, Lin TH, Wu MS, Wu CJ, Chan YL, Liao KW. Helicobacter pylori-derived heat shock protein 60 increases the induction of regulatory T-cells associated with persistent infection. Microb Pathog 2018; 119:152-161. [PMID: 29660522 DOI: 10.1016/j.micpath.2018.04.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/26/2018] [Accepted: 04/10/2018] [Indexed: 02/06/2023]
Abstract
Local Treg responses are involved in Helicobacter pylori-related inflammation and clinical outcomes after infection, and H. pylori-derived HSP60 (HpHSP60) is an important virulence factor associated with gastric carcinogenesis. This study to investigate the role of HpHSP60 in immunosuppression, particularly with regard to whether it could induce the production of Treg cells. For this purpose, human peripheral blood mononuclear cells (PBMCs) were treated with or without HpHSP60 in the presence of an anti-CD3 mAb to determine the effect of HpHSP60 on cell proliferation. In this report, HpHSP60 decreased the expression of CDK4 to significantly arrest the proliferation of mitogen-stimulated T-cells, which correlated with the induction of Treg cells. Moreover, monocytic cells were essential for the induction of HpHSP60-induced Treg cells via the secretion of IL-10 and TGF-β after treatment with HpHSP60. Blockage of HpHSP60 with specific monoclonal antibodies significantly reduced the colonization of H. pylori and the expression of Treg cells in vivo. Overall, our results suggest that HpHSP60 could act on macrophages to trigger the expression of IL-10 and TGF-β, thereby leading to an increase in Treg cells and inhibition of T-cell proliferation.
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Affiliation(s)
- Wei-Tung Hsu
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Shu-Yi Ho
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Ting-Yan Jian
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Han-Ning Huang
- Department of Food Science and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan, ROC
| | - Yu-Ling Lin
- Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC; Center for Bioinformatics Research, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Chia-Hung Chen
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Tsung-Han Lin
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan, ROC
| | - Ming-Shiang Wu
- Department of Internal Medicine, College of Medicine, National Taiwan University Hospital, Taipei, Taiwan, ROC
| | - Chang-Jer Wu
- Department of Food Science and Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan, ROC; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan, ROC; Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan, ROC; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC
| | - Yi-Lin Chan
- Department of Life Science, Chinese Culture University, Taipei, Taiwan, ROC
| | - Kuang-Wen Liao
- Institute of Molecular Medicine and Bioengineering, National Chiao Tung University, Hsinchu, Taiwan, ROC; Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC; College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC.
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7
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Jafarzadeh A, Larussa T, Nemati M, Jalapour S. T cell subsets play an important role in the determination of the clinical outcome of Helicobacter pylori infection. Microb Pathog 2018; 116:227-236. [PMID: 29407232 DOI: 10.1016/j.micpath.2018.01.040] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/20/2018] [Accepted: 01/26/2018] [Indexed: 12/12/2022]
Abstract
Helicobacter pylori (H. pylori) is one of the most prevalent human pathogen and a persistent infection with this bacterium causes common pathologies, such as gastritis or peptic ulcers, and also less common but more serious pathologies, such as gastric cancer or gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The clinical outcome of gastrointestinal infection sustained by H. pylori is determined by the reciprocal interactions between virulence factors of the bacterium and host factors, including immune response genes. Although H. pylori induces a strong immune response, the bacterium is not eliminated. The eradication failure could be attributed to the bacterial capability to regulate helper T (Th) cell-related responses. H. pylori specific CD4+ T cells play a fundamental role in regulating host immunity and immunopathologic events. It has been documented that Th1, Th2, Th9, Th17, Th22 and T regulatory (Treg) cells, separately or in coordination with each other, can affect the outcome of the infection sustained by of H. pylori. Some studies indicated that both Th1 and Th17 cells may be protective or pathogenic, whereas Treg and Th2 cells perform anti-inflammatory impacts during H. pylori infection. This review gathers recent information regarding the association of the CD4+ T cells-mediated immunological responses and the clinical consequence of H. pylori infection.
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Affiliation(s)
- Abdollah Jafarzadeh
- Immunology of Infectious Diseases Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Department of Immunology, School of Medicine, Rafsanjan University of Medical Sciences, Rafsanjan, Iran; Department of Immunology, School of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
| | - Tiziana Larussa
- Department of Health Science, University of Catanzaro "Magna Graecia", 88100 Catanzaro, Italy
| | - Maryam Nemati
- Department of Laboratory Sciences, School of Para-Medicine, Kerman University of Medical Sciences, Kerman, Iran
| | - Shila Jalapour
- Molecular Medicine Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran.
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8
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Weingartner E, Golding A. Direct control of B cells by Tregs: An opportunity for long-term modulation of the humoral response. Cell Immunol 2017; 318:8-16. [DOI: 10.1016/j.cellimm.2017.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/20/2017] [Accepted: 05/28/2017] [Indexed: 12/23/2022]
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9
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A Gain-Of-Function Mutation in the Plcg2 Gene Protects Mice from Helicobacter felis-Induced Gastric MALT Lymphoma. PLoS One 2016; 11:e0150411. [PMID: 26966907 PMCID: PMC4788355 DOI: 10.1371/journal.pone.0150411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 02/13/2016] [Indexed: 01/04/2023] Open
Abstract
Gastric mucosa-associated lymphoid tissue (MALT) lymphomas develop from a chronic Helicobacter infection. Phospholipase C gamma 2 (PLCG2) is important for B-cell survival and proliferation. We used BALB/c mice with a gain-of-function mutation in the Plcg2 gene (Ali5) to analyze its role in the development of gastric MALT lymphoma. Heterozygous BALB/c Plcg2Ali5/+ and wildtype (WT) mice were infected with Helicobacter felis (H. felis) and observed up to 16 months for development of gastric MALT lymphomas. In contrast to our initial hypothesis, Plcg2Ali5/+ mice developed MALT lymphomas less frequently than their WT littermates after long-term infection of 16 months. Infected Plcg2Ali5/+ mice showed downregulation of proinflammatory cytokines and decreased H. felis-specific IgG1 and IgG2a antibody responses. These results suggested a blunted immune response of Plcg2Ali5/+ mice towards H. felis infection. Intriguingly, Plcg2Ali5/+ mice harboured higher numbers of CD73 expressing regulatory T cells (Tregs), possibly responsible for impaired immune response towards Helicobacter infection. We suggest that Plcg2Ali5/+ mice may be protected from developing gastric MALT lymphomas as a result of elevated Treg numbers, reduced response to H. felis and decrease of proinflammatory cytokines.
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Hussain K, Letley DP, Greenaway AB, Kenefeck R, Winter JA, Tomlinson W, Rhead J, Staples E, Kaneko K, Atherton JC, Robinson K. Helicobacter pylori-Mediated Protection from Allergy Is Associated with IL-10-Secreting Peripheral Blood Regulatory T Cells. Front Immunol 2016; 7:71. [PMID: 27014260 PMCID: PMC4779884 DOI: 10.3389/fimmu.2016.00071] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/15/2016] [Indexed: 12/18/2022] Open
Abstract
Helicobacter pylori infections are usually established in early childhood and continuously stimulate immunity, including T-helper 1 (Th1), Th17, and regulatory T-cell (Treg) responses, throughout life. Although known to be the major cause of peptic ulcer disease and gastric cancer, disease occurs in a minority of those who are infected. Recently, there has been much interest in beneficial effects arising from infection with this pathogen. Published data robustly show that the infection is protective against asthma in mouse models. Epidemiological studies show that H. pylori is inversely associated with human allergy and asthma, but there is a paucity of mechanistic data to explain this. Since Th1 and Treg responses are reported to protect against allergic responses, we investigated if there were links between the human systemic Th1 and Treg response to H. pylori and allergen-specific IgE levels. The human cytokine and T-cell responses were examined using peripheral blood mononuclear cells (PBMCs) from 49 infected and 58 uninfected adult patients. Concentrations of total and allergen-specific plasma IgE were determined by ELISA and ImmunoCAP assays. These responses were analyzed according to major virulence factor genotypes of the patients' colonizing H. pylori strains. An in vitro assay was employed, using PBMCs from infected and uninfected donors, to determine the role of Treg cytokines in the suppression of IgE. Significantly higher frequencies of IL-10-secreting CD4(+)CD25(hi) Tregs, but not H. pylori-specific Th1 cells, were present in the peripheral blood of infected patients. Total and allergen-specific IgE concentrations were lower when there was a strong Treg response, and blocking IL-10 in vitro dramatically restored IgE responses. IgE concentrations were also significantly lower when patients were infected with CagA(+) strains or those expressing the more active i1 form of VacA. The systemic IL-10(+) Treg response is therefore likely to play a role in H. pylori-mediated protection against allergy in humans.
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Affiliation(s)
- Khiyam Hussain
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Darren P Letley
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - A Borgel Greenaway
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Rupert Kenefeck
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Jody A Winter
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - William Tomlinson
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Joanne Rhead
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Emily Staples
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Kazuyo Kaneko
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - John C Atherton
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Karen Robinson
- Nottingham Digestive Diseases Biomedical Research Unit, Queen's Medical Centre, Nottingham University Hospitals, Nottingham, UK; Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
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11
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Helicobacter pylori and T Helper Cells: Mechanisms of Immune Escape and Tolerance. J Immunol Res 2015. [PMID: 26525279 DOI: 10.1155/7015/981328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Helicobacter pylori colonizes the gastric mucosa of at least half of the human population, causing a worldwide infection that appears in early childhood and if not treated, it can persist for life. The presence of symptoms and their severity depend on bacterial components, host susceptibility, and environmental factors, which allow H. pylori to switch between commensalism and pathogenicity. H. pylori-driven interactions with the host immune system underlie the persistence of the infection in humans, since the bacterium is able to interfere with the activity of innate and adaptive immune cells, reducing the inflammatory response in its favour. Gastritis due to H. pylori results from a complex interaction between several T cell subsets. In particular, H. pylori is known to induce a T helper (Th)1/Th17 cell response-driven gastritis, whose impaired modulation caused by the bacterium is thought to sustain the ongoing inflammatory condition and the unsuccessful clearing of the infection. In this review we discuss the current findings underlying the mechanisms implemented by H. pylori to alter the T helper lymphocyte proliferation, thus facilitating the development of chronic infections and allowing the survival of the bacterium in the human host.
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12
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Helicobacter pylori and T Helper Cells: Mechanisms of Immune Escape and Tolerance. J Immunol Res 2015; 2015:981328. [PMID: 26525279 PMCID: PMC4615206 DOI: 10.1155/2015/981328] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/29/2015] [Indexed: 12/18/2022] Open
Abstract
Helicobacter pylori colonizes the gastric mucosa of at least half of the human population, causing a worldwide infection that appears in early childhood and if not treated, it can persist for life. The presence of symptoms and their severity depend on bacterial components, host susceptibility, and environmental factors, which allow H. pylori to switch between commensalism and pathogenicity. H. pylori-driven interactions with the host immune system underlie the persistence of the infection in humans, since the bacterium is able to interfere with the activity of innate and adaptive immune cells, reducing the inflammatory response in its favour. Gastritis due to H. pylori results from a complex interaction between several T cell subsets. In particular, H. pylori is known to induce a T helper (Th)1/Th17 cell response-driven gastritis, whose impaired modulation caused by the bacterium is thought to sustain the ongoing inflammatory condition and the unsuccessful clearing of the infection. In this review we discuss the current findings underlying the mechanisms implemented by H. pylori to alter the T helper lymphocyte proliferation, thus facilitating the development of chronic infections and allowing the survival of the bacterium in the human host.
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13
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Robinson K. Helicobacter pylori-Mediated Protection against Extra-Gastric Immune and Inflammatory Disorders: The Evidence and Controversies. Diseases 2015; 3:34-55. [PMID: 28943607 PMCID: PMC5548235 DOI: 10.3390/diseases3020034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/03/2015] [Accepted: 03/05/2015] [Indexed: 12/11/2022] Open
Abstract
A large number of studies link H. pylori infection with a reduced risk of developing extra-gastric conditions such as allergy, asthma, inflammatory bowel disease, coeliac disease and multiple sclerosis. The strength of the evidence for these protective associations is quite variable, and published studies often do not agree. This review article discusses some of the reasons for these discrepancies, and the difficulties faced when designing studies. Examples of some protective disease associations are described in detail, where the evidence is most abundant and thought to be more reliable. The most convincing of these are supported by published mechanistic data, for example with animal models, or incidence of disease exacerbation in humans following H. pylori eradication. Although controversial, this field is very important as the prevalence of H. pylori is decreasing throughout the world whilst many chronic diseases are becoming more common. These trends are likely to continue in the future, therefore it is important that we fully understand if and how H. pylori confers protection.
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Affiliation(s)
- Karen Robinson
- Nottingham Digestive Diseases Biomedical Research Unit, School of Medicine, University of Nottingham, Nottingham NG7 2RD, UK.
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14
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Li K, Wang C, Lu H, Gu X, Guan Z, Zhou P. Regulatory T cells in peripheral blood and cerebrospinal fluid of syphilis patients with and without neurological involvement. PLoS Negl Trop Dis 2013; 7:e2528. [PMID: 24244772 PMCID: PMC3820703 DOI: 10.1371/journal.pntd.0002528] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 09/28/2013] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Syphilis, a sexually transmitted disease caused by spirochetal bacterium Treponema pallidum, can progress to affect the central nervous system, causing neurosyphilis. Accumulating evidence suggest that regulatory T cells (Tregs) may play an important role in the pathogenesis of syphilis. However, little is known about Treg response in neurosyphilis. METHODOLOGY/PRINCIPAL FINDINGS We analyzed Treg frequencies and Transforming Growth Factor-β (TGF-β) levels in the blood and CSF of 431 syphilis patients without neurological involvement, 100 neurosyphilis patients and 100 healthy donors. Suppressive function of Tregs in peripheral blood was also assessed. Among syphilis patients without neurological involvement, we found that secondary and serofast patients had increased Treg percentages, suppressive function and TGF-β levels in peripheral blood compared to healthy donors. Serum Rapid Plasma Reagin (RPR) titers were positively correlated with Treg numbers in these patients. Compared to these syphilis patients without neurological involvement, neurosyphilis patients had higher Treg frequency in peripheral blood. In the central nervous system, neurosyphilis patients had higher numbers of leukocytes in CSF compared to syphilis patients without neurological involvement. CD4(+) T cells were the predominant cell type in the inflammatory infiltrates in CSF of neurosyphilis patients. Interestingly, among these neurosyphilis patients, a significant decrease in CSF CD4(+) CD25(high) Treg percentage and number was observed in symptomatic neurosyphilis patients compared to those of asymptomatic neurosyphilis patients, which may be associated with low CSF TGF-β levels. CONCLUSIONS Our findings suggest that Tregs might play an important role in both bacterial persistence and neurologic compromise in the pathogenesis of syphilis.
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Affiliation(s)
- Kang Li
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
| | - Cuini Wang
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
| | - Haikong Lu
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
| | - Xin Gu
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
| | - Zhifang Guan
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
| | - Pingyu Zhou
- STD Institute, Shanghai Skin Disease Hospital, Shanghai, People's Republic of China
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Myers L, Joedicke JJ, Carmody AB, Messer RJ, Kassiotis G, Dudley JP, Dittmer U, Hasenkrug KJ. IL-2-independent and TNF-α-dependent expansion of Vβ5+ natural regulatory T cells during retrovirus infection. THE JOURNAL OF IMMUNOLOGY 2013; 190:5485-95. [PMID: 23645880 DOI: 10.4049/jimmunol.1202951] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Friend virus infection of mice induces the expansion and activation of regulatory T cells (Tregs) that dampen acute immune responses and promote the establishment and maintenance of chronic infection. Adoptive transfer experiments and the expression of neuropilin-1 indicate that these cells are predominantly natural Tregs rather than virus-specific conventional CD4(+) T cells that converted into induced Tregs. Analysis of Treg TCR Vβ chain usage revealed a broadly distributed polyclonal response with a high proportionate expansion of the Vβ5(+) Treg subset, which is known to be responsive to endogenous retrovirus-encoded superantigens. In contrast to the major population of Tregs, the Vβ5(+) subset expressed markers of terminally differentiated effector cells, and their expansion was associated with the level of the antiviral CD8(+) T cell response rather than the level of Friend virus infection. Surprisingly, the expansion and accumulation of the Vβ5(+) Tregs was IL-2 independent but dependent on TNF-α. These experiments reveal a subset-specific Treg induction by a new pathway.
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Affiliation(s)
- Lara Myers
- Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT 59840, USA
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16
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Complex T cell interactions contribute to Helicobacter pylori gastritis in mice. Infect Immun 2012; 81:740-52. [PMID: 23264048 DOI: 10.1128/iai.01269-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Disease due to the gastric pathogen Helicobacter pylori varies in severity from asymptomatic to peptic ulcer disease and cancer. Accumulating evidence suggests that one source of this variation is an abnormal host response. The goal of this study was to use a mouse model of H. pylori gastritis to investigate the roles of regulatory T cells (Treg) as well as proinflammatory T cells (Th1 and Th17) in gastritis, gastric T cell engraftment, and gastric cytokine production. Our results support published data indicating that severe gastritis in T cell recipient mice is due to failure of Treg engraftment, that Treg ameliorate gastritis, and that the proinflammatory response is attributable to interactions between several cell subsets and cytokines. We confirmed that gamma interferon (IFN-γ) is essential for induction of gastritis but showed that IFN-γ-producing CD4 T cells are not necessary. Interleukin 17A (IL-17A) also contributed to gastritis, but to a lesser extent than IFN-γ. Tumor necrosis factor alpha (TNF-α) and IL-17F were also elevated in association with disease. These results indicate that while H. pylori-specific CD4(+) T cells and IFN-γ are both essential for induction of gastritis due to H. pylori, IFN-γ production by T cells is not essential. It is likely that other proinflammatory cytokines, such as IL-17F and TNF-α, shown to be elevated in this model, also contribute to the induction of disease. We suggest that gastritis due to H. pylori is associated with loss of immunoregulation and alteration of several cytokines and cell subsets and cannot be attributed to a single immune pathway.
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17
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Walduck AK, Becher D. Leptin, CD4(+) T(reg) and the prospects for vaccination against H. pylori infection. Front Immunol 2012; 3:316. [PMID: 23087691 PMCID: PMC3470998 DOI: 10.3389/fimmu.2012.00316] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/24/2012] [Indexed: 12/15/2022] Open
Abstract
Helicobacter pylori infection induces chronic inflammation which is characterized not only by infiltrations of inflammatory cells such as neutrophils and CD4+ T cells, but also significant populations of regulatory T cells (Treg). These cells are important for disease pathogenesis because they are believed to contribute to the persistence of the infection. Despite encouraging results in animal models, the prospects for an effective H. pylori vaccine are currently poor because of generally disappointing results in preclinical and phase 1 trials. As a result, a current major focus of basic research on vaccination is to better understand the mechanisms regulating the inflammatory response with the view it can inform future vaccine design. Our studies in this area have focused on gastric CD4+ Treg in vaccinated mice, and raised the hypothesis that adipokines in particular leptin are involved the establishment of a protective gastric immune response. Here we discuss the hypothesis that vaccination deregulates Treg responses in the gastric mucosa, and that this process is mediated by leptin. We propose that reduced suppression permits a protective sub population of H. pylori-specific CD4+ T cells to exert protective effects, presumably via the gastric epithelium. Evidence from the literature and experimental approaches will be discussed.
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Affiliation(s)
- Anna K Walduck
- Department of Microbiology and Immunology, University of Melbourne Parkville, VIC, Australia
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18
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Okwor I, Onyilagha C, Kuriakose S, Mou Z, Jia P, Uzonna JE. Regulatory T cells enhance susceptibility to experimental Trypanosoma congolense infection independent of mouse genetic background. PLoS Negl Trop Dis 2012; 6:e1761. [PMID: 22860150 PMCID: PMC3409116 DOI: 10.1371/journal.pntd.0001761] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 06/20/2012] [Indexed: 12/22/2022] Open
Abstract
Background BALB/c mice are highly susceptible while C57BL/6 are relatively resistant to experimental Trypanosoma congolense infection. Although regulatory T cells (Tregs) have been shown to regulate the pathogenesis of experimental T. congolense infection, their exact role remains controversial. We wished to determine whether Tregs contribute to distinct phenotypic outcomes in BALB/c and C57BL/6 mice and if so how they operate with respect to control of parasitemia and production of disease-exacerbating proinflammatory cytokines. Methodology/Findings BALB/c and C57BL/6 mice were infected intraperitoneally (i.p) with 103T. congolense clone TC13 and both the kinetics of Tregs expansion and intracellular cytokine profiles in the spleens and livers were monitored directly ex vivo by flow cytometry. In some experiments, mice were injected with anti-CD25 mAb prior or post T. congolense infection or adoptively (by intravenous route) given highly enriched naïve CD25+ T lymphocytes prior to T. congolense infection and the inflammatory cytokine/chemokine levels and survival were monitored. In contrast to a transient and non significant increase in the percentages and absolute numbers of CD4+CD25+Foxp3+ T cells (Tregs) in C57BL/6 mouse spleens and livers, a significant increase in the percentage and absolute numbers of Tregs was observed in spleens of infected BALB/c mice. Ablation or increasing the number of CD25+ cells in the relatively resistant C57BL/6 mice by anti-CD25 mAb treatment or by adoptive transfer of CD25+ T cells, respectively, ameliorates or exacerbates parasitemia and production of proinflammatory cytokines. Conclusion Collectively, our results show that regulatory T cells contribute to susceptibility in experimental murine trypanosomiasis in both the highly susceptible BALB/c and relatively resistant C57BL/6 mice. BALB/c mice are highly susceptible while C57BL/6 is relatively resistant to experimental Trypanosoma congolense infection. Acute death observed in infected BALB/c mice is usually associated with the excessive production of pro-inflammatory cytokines. Regulatory T cells (Tregs) have been shown to play a significant role in the pathogenesis of many diseases including those caused by parasites. However, the role of Tregs in the pathogenesis of T. congolense infection remains unclear. We were interested in addressing the following questions: Do Tregs contribute to the distinct phenotypic outcomes observed in T. congolense-infected BALB/c and C57BL/6 mice? If so, where and how do they operate with respect to parasitemia and cytokine response? By selectively altering the numbers of these cells either by targeted depletion with monoclonal antibody or adoptive transfer of highly enriched naïve CD25+ cells prior to infection, we show that Tregs impairs efficient parasite control and impacts on production of disease-exacerbating proinflammatory cytokines. Collectively, our findings suggest that Tregs contribute to enhanced susceptibility to experimental T. congolense infection in mice.
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Affiliation(s)
- Ifeoma Okwor
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Chukwunonso Onyilagha
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Shiby Kuriakose
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Zhirong Mou
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ping Jia
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jude E. Uzonna
- Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Immunology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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19
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Rowe JH, Ertelt JM, Way SS. Foxp3(+) regulatory T cells, immune stimulation and host defence against infection. Immunology 2012; 136:1-10. [PMID: 22211994 PMCID: PMC3372751 DOI: 10.1111/j.1365-2567.2011.03551.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The immune system is intricately regulated allowing potent effectors to expand and become rapidly mobilized after infection, while simultaneously silencing potentially detrimental responses that averts immune-mediated damage to host tissues. This relies in large part on the delicate interplay between immune suppressive regulatory CD4+ T (Treg) cells and immune effectors that without active suppression by Treg cells cause systemic and organ-specific autoimmunity. Although these beneficial roles have been classically described as counterbalanced by impaired host defence against infection, newfound protective roles for Treg cells against specific viral pathogens (e.g. herpes simplex virus 2, lymphocytic choriomeningitis virus, West Nile virus) have been uncovered using transgenic mice that allow in vivo Treg-cell ablation based on Foxp3 expression. In turn, Foxp3+ Treg cells also provide protection against some parasitic (Plasmodium sp., Toxoplasma gondii) and fungal (Candida albicans) pathogens. By contrast, for bacterial and mycobacterial infections (e.g. Listeria monocytogenes, Salmonella enterica, Mycobacterium tuberculosis), experimental manipulation of Foxp3+ cells continues to indicate detrimental roles for Treg cells in host defence. This variance is probably related to functional plasticity in Treg cell suppression that shifts discordantly following infection with different types of pathogens. Furthermore, the efficiency whereby Treg cells silence immune activation coupled with the plasticity in Foxp3+ cell activity suggest that overriding Treg-mediated suppression represents a prerequisite ‘signal zero’ that together with other stimulation signals [T-cell receptor (signal 1), co-stimulation (signal 2), inflammatory cytokines (signal 3)] are essential for T-cell activation in vivo. Herein, the importance of Foxp3+ Treg cells in host defence against infection, and the significance of infection-induced shifts in Treg-cell suppression are summarized.
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Affiliation(s)
- Jared H Rowe
- Departments of Pediatrics and Microbiology, University of Minnesota School of Medicine, Center for Infectious Disease and Microbiology Translational Research, Minneapolis, MN 55455, USA
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20
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Alexander CM, Tygrett LT, Boyden AW, Wolniak KL, Legge KL, Waldschmidt TJ. T regulatory cells participate in the control of germinal centre reactions. Immunology 2011; 133:452-68. [PMID: 21635248 DOI: 10.1111/j.1365-2567.2011.03456.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Germinal centre (GC) reactions are central features of T-cell-driven B-cell responses, and the site where antibody-producing cells and memory B cells are generated. Within GCs, a range of complex cellular and molecular events occur which are critical for the generation of high affinity antibodies. These processes require exquisite regulation not only to ensure the production of desired antibodies, but to minimize unwanted autoreactive or low affinity antibodies. To assess whether T regulatory (Treg) cells participate in the control of GC responses, immunized mice were treated with an anti-glucocorticoid-induced tumour necrosis factor receptor-related protein (GITR) monoclonal antibody (mAb) to disrupt Treg-cell activity. In anti-GITR-treated mice, the GC B-cell pool was significantly larger compared with control-treated animals, with switched GC B cells composing an abnormally high proportion of the response. Dysregulated GCs were also observed regardless of strain, T helper type 1 or 2 polarizing antigens, and were also seen after anti-CD25 mAb treatment. Within the spleens of immunized mice, CXCR5(+) and CCR7(-) Treg cells were documented by flow cytometry and Foxp3(+) cells were found within GCs using immunohistology. Final studies demonstrated administration of either anti-transforming growth factor-β or anti-interleukin-10 receptor blocking mAb to likewise result in dysregulated GCs, suggesting that generation of inducible Treg cells is important in controlling the GC response. Taken together, these findings indicate that Treg cells contribute to the overall size and quality of the humoral response by controlling homeostasis within GCs.
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Affiliation(s)
- Carla-Maria Alexander
- Department of Pathology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, IA 52242, USA
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21
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Moss SF, Moise L, Lee DS, Kim W, Zhang S, Lee J, Rogers AB, Martin W, De Groot AS. HelicoVax: epitope-based therapeutic Helicobacter pylori vaccination in a mouse model. Vaccine 2011; 29:2085-91. [PMID: 21236233 DOI: 10.1016/j.vaccine.2010.12.130] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 12/22/2010] [Accepted: 12/27/2010] [Indexed: 12/12/2022]
Abstract
Helicobacter pylori is the leading cause of gastritis, peptic ulcer disease and gastric adenocarcinoma and lymphoma in humans. Due to the decreasing efficacy of anti-H. pylori antibiotic therapy in clinical practice, there is renewed interest in the development of anti-H. pylori vaccines. In this study an in silico-based approach was utilized to develop a multi-epitope DNA-prime/peptide-boost immunization strategy using informatics tools. The efficacy of this construct was then assessed as a therapeutic vaccine in a mouse model of gastric cancer induced by chronic H. pylori infection. The multi-epitope vaccine administered intranasally induced a broad immune response as determined by interferon-gamma production in ELISpot assays. This was associated with a significant reduction in H. pylori colonization compared with mice immunized with the same vaccine intramuscularly, given an empty plasmid, or given a whole H. pylori lysate intranasally as the immunogen. Total scores of gastric histological changes were not significantly different among the 4 experimental groups. These results suggest that further development of an epitope-based mucosal vaccine may be beneficial in eradicating H. pylori and reducing the burden of the associated gastric diseases in humans.
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Affiliation(s)
- Steven F Moss
- Department of Medicine, Division of Gastroenterology, Rhode Island Hospital & Warren Alpert Medical School of Brown University, Providence, RI 02903, USA. Steven
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22
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Abstract
Infectious agents have intimately co-evolved with the host immune system, acquiring a portfolio of highly sophisticated mechanisms to modulate immunity. Among the common strategies developed by viruses, bacteria, protozoa, helminths, and fungi is the manipulation of the regulatory T cell network in order to favor pathogen survival and transmission. Treg activity also benefits the host in many circumstances by controlling immunopathogenic reactions to infection. Interestingly, some pathogens are able to directly induce the conversion of naive T cells into suppressive Foxp3-expressing Tregs, while others activate pre-existing natural Tregs, in both cases repressing pathogen-specific effector responses. However, Tregs can also act to promote immunity in certain settings, such as in initial stages of infection when effector cells must access the site of infection, and subsequently in ensuring generation of effector memory. Notably, there is little current information on whether infections selectively drive pathogen-specific Tregs, and if so whether these cells are also reactive to self-antigens. Further analysis of specificity, together with a clearer picture of the relative dynamics of Treg subsets over the course of disease, should lead to rational strategies for immune intervention to optimize immunity and eliminate infection.
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23
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Helicobacter pylori and gastric cancer: factors that modulate disease risk. Clin Microbiol Rev 2010; 23:713-39. [PMID: 20930071 DOI: 10.1128/cmr.00011-10] [Citation(s) in RCA: 908] [Impact Index Per Article: 64.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori is a gastric pathogen that colonizes approximately 50% of the world's population. Infection with H. pylori causes chronic inflammation and significantly increases the risk of developing duodenal and gastric ulcer disease and gastric cancer. Infection with H. pylori is the strongest known risk factor for gastric cancer, which is the second leading cause of cancer-related deaths worldwide. Once H. pylori colonizes the gastric environment, it persists for the lifetime of the host, suggesting that the host immune response is ineffective in clearing this bacterium. In this review, we discuss the host immune response and examine other host factors that increase the pathogenic potential of this bacterium, including host polymorphisms, alterations to the apical-junctional complex, and the effects of environmental factors. In addition to host effects and responses, H. pylori strains are genetically diverse. We discuss the main virulence determinants in H. pylori strains and the correlation between these and the diverse clinical outcomes following H. pylori infection. Since H. pylori inhibits the gastric epithelium of half of the world, it is crucial that we continue to gain understanding of host and microbial factors that increase the risk of developing more severe clinical outcomes.
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Becher D, Deutscher ME, Simpfendorfer KR, Wijburg OL, Pederson JS, Lew AM, Strugnell RA, Walduck AK. Local recall responses in the stomach involving reduced regulation and expanded help mediate vaccine-induced protection against Helicobacter pylori in mice. Eur J Immunol 2010; 40:2778-90. [PMID: 21038469 DOI: 10.1002/eji.200940219] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Helicobacter pylori is recognised as the chief cause of chronic gastritis, ulcers and gastric cancer in humans. With increased incidence of treatment failure and antibiotic resistance, development of prophylactic or therapeutic vaccination is a desirable alternative. Although the results of vaccination studies in animal models have been promising, studies in human volunteers have revealed problems such as 'post-immunisation gastritis' and comparatively poor responses to vaccine antigens. The focus of this study was to compare the gastric and systemic cellular immune responses induced by recombinant attenuated Salmonella Typhimurium-based vaccination in the C57BL/6 model of H. pylori infection. Analysis of lymphocyte populations in the gastric mucosa, blood, spleen, paragastric LN and MLN revealed that the effects of vaccination were largely confined to the parenchymal stomach rather than lymphoid organs. Vaccine-induced protection was correlated with an augmented local recall response in the gastric mucosa, with increased proportions of CD4(+) T cells, neutrophils and reduced proportions of CD4(+) Treg. CD4(+) T cells isolated from the stomachs of vaccinated mice proliferated ex vivo in response to H. pylori antigen, and secreted Th1 cytokines, particularly IFN-γ. This detailed analysis of local gastric immune responses provides insight into the mechanism of vaccine-induced protection.
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Affiliation(s)
- Dorit Becher
- Department of Microbiology and Immunology, University of Melbourne, VIC, Australia
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25
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Sundquist M, Quiding-Järbrink M. Helicobacter pylori and its effect on innate and adaptive immunity: new insights and vaccination strategies. Expert Rev Gastroenterol Hepatol 2010; 4:733-44. [PMID: 21108593 DOI: 10.1586/egh.10.71] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Infection with the gastric bacterium Helicobacter pylori invariably leads to active chronic gastritis, and is strongly correlated to peptic ulcer disease, gastric adenocarcinoma and mucosa-associated lymphoid tissue lymphoma. The infection leads to local accumulation of inflammatory cells and strong activation of B- and T-cell immunity. Still, the immune response can not eliminate the bacteria, and unless antibiotic treatment is used, the infection is usually lifelong. During the last few years, several immunomodulatory properties of H. pylori have been described, which probably contribute to the inability of the immune system to eradicate the bacterium. Another factor promoting bacterial persistence is probably the induction of a substantial regulatory T-cell response by the infection. Several different immunization schedules have resulted in protective immunity in animal models, while in humans no reliable vaccine is available as yet. In this article, we describe the innate and adaptive immune responses to H. pylori, and the attempts to create an effective vaccine.
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Affiliation(s)
- Malin Sundquist
- Department of Microbiology and Immunology, The Sahlgrenska Academy at the University of Gothenburg, P.O. Box 435, 405 30 Göteborg, Sweden
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26
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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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27
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Bedoui S, Kupz A, Wijburg OL, Walduck AK, Rescigno M, Strugnell RA. Different bacterial pathogens, different strategies, yet the aim is the same: evasion of intestinal dendritic cell recognition. THE JOURNAL OF IMMUNOLOGY 2010; 184:2237-42. [PMID: 20164434 DOI: 10.4049/jimmunol.0902871] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Given the central role of intestinal dendritic cells (DCs) in the regulation of gut immune responses, it is not surprising that several bacterial pathogens have evolved strategies to prevent or bypass recognition by DCs. In this article, we will review recent findings on the interaction between intestinal DCs and prototypical bacterial pathogens, such as Salmonella, Yersinia, or Helicobacter. We will discuss the different approaches with which these pathogens seek to evade DC recognition and subsequent T cell activation. These diverse strategies span to include mounting irrelevant immune responses, inhibition of Ag presentation by DCs, and stretch as far as to manipulate the Th1/Th2 balance of CD4(+) T cells in the bacteria's favor.
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Affiliation(s)
- Sammy Bedoui
- Department of Microbiology and Immunology, University of Melbourne, Gate 11, Royal Parade, Parkville 3010, Victoria, Australia. E-mail address:
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28
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Wang X, Zhou S, Chi Y, Wen X, Hoellwarth J, He L, Liu F, Wu C, Dhesi S, Zhao J, Hu W, Su C. CD4+CD25+ Treg induction by an HSP60-derived peptide SJMHE1 from Schistosoma japonicum is TLR2 dependent. Eur J Immunol 2010; 39:3052-65. [PMID: 19882655 DOI: 10.1002/eji.200939335] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Chronic schistosome infection results in the suppression of host immune responses, allowing long-term schistosome survival and restricting pathology. Current theories suggest that Treg play an important role in this regulation. However, the mechanism of Treg induction during schistosome infection is still unknown. The aim of this study was to determine the mechanism behind the induction of CD4(+)CD25(+) T cells by Schistosoma japonicum HSP60 (SjHSP60)-derived peptide SJMHE1 as well as to elucidate the cellular and molecular basis for the induction of CD4(+)CD25(+) T cells during S. japonicum infection. Mice immunized with SJMHE1 or spleen and LN cells from naïve mice pretreated with SJMHE1 in vitro all displayed an increase in CD4(+)CD25(+) T-cell populations. Release of IL-10 and TGF-beta by SJMHE1 stimulation may contribute to suppression. Adoptively transferred SJMHE1-induced CD4(+)CD25(+) T cells inhibited delayed-type hypersensitivity in BALB/c mice. Additionally, SJMHE1-treated APC were tolerogenic and induced CD4(+) cells to differentiate into suppressive CD4(+)CD25(+) Treg. Furthermore, our data support a role for TLR2 in SJMHE1-mediated CD4(+)CD25(+) Treg induction. These findings provide the basis for a more complete understanding of the S. japonicum-host interactions that contribute to host homeostatic mechanisms, preventing an excessive immune response.
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Affiliation(s)
- Xuefeng Wang
- Department of Pathogen Biology & Immunology, Department of Pharmacology, Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, PR China
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Kaparakis M, Turnbull L, Carneiro L, Firth S, Coleman HA, Parkington HC, Le Bourhis L, Karrar A, Viala J, Mak J, Hutton ML, Davies JK, Crack PJ, Hertzog PJ, Philpott DJ, Girardin SE, Whitchurch CB, Ferrero RL. Bacterial membrane vesicles deliver peptidoglycan to NOD1 in epithelial cells. Cell Microbiol 2009; 12:372-85. [PMID: 19888989 DOI: 10.1111/j.1462-5822.2009.01404.x] [Citation(s) in RCA: 306] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Gram-negative bacterial peptidoglycan is specifically recognized by the host intracellular sensor NOD1, resulting in the generation of innate immune responses. Although epithelial cells are normally refractory to external stimulation with peptidoglycan, these cells have been shown to respond in a NOD1-dependent manner to Gram-negative pathogens that can either invade or secrete factors into host cells. In the present work, we report that Gram-negative bacteria can deliver peptidoglycan to cytosolic NOD1 in host cells via a novel mechanism involving outer membrane vesicles (OMVs). We purified OMVs from the Gram-negative mucosal pathogens: Helicobacter pylori, Pseudomonas aeruginosa and Neisseria gonorrhoea and demonstrated that these peptidoglycan containing OMVs upregulated NF-kappaB and NOD1-dependent responses in vitro. These OMVs entered epithelial cells through lipid rafts thereby inducing NOD1-dependent responses in vitro. Moreover, OMVs delivered intragastrically to mice-induced innate and adaptive immune responses via a NOD1-dependent but TLR-independent mechanism. Collectively, our findings identify OMVs as a generalized mechanism whereby Gram-negative bacteria deliver peptidoglycan to cytosolic NOD1. We propose that OMVs released by bacteria in vivo may promote inflammation and pathology in infected hosts.
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Affiliation(s)
- Maria Kaparakis
- Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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Abstract
Each microenvironment requires a specific set of regulatory elements that are finely and constantly tuned to maintain local homeostasis. Various populations of regulatory T cells contribute to the maintenance of this equilibrium and establishment of controlled immune responses. In particular, regulatory T cells limit the magnitude of effector responses, which may result in failure to adequately control infection. However, regulatory T cells also help limit collateral tissue damage caused by vigorous antimicrobial immune responses against pathogenic microbes as well as commensals. In this review, we describe various situations in which the balance between regulatory T cells and effector immune functions influence the outcome of host-microorganism coexistence and discuss current hypotheses and points of polemic associated with the origin, target, and antigen specificity of both endogenous and induced regulatory T cells during these interactions.
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Affiliation(s)
- Yasmine Belkaid
- Mucosal Immunology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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McGee HS, Edwan JH, Agrawal DK. Flt3-L increases CD4+CD25+Foxp3+ICOS+ cells in the lungs of cockroach-sensitized and -challenged mice. Am J Respir Cell Mol Biol 2009; 42:331-40. [PMID: 19448155 DOI: 10.1165/rcmb.2008-0397oc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We previously reported in an ovalbumin-induced model of allergic asthma that Fms-like tyrosine kinase 3 ligand (Flt3-L) reversed airway hyperresponsiveness (AHR) and airway inflammation, and increased the number of regulatory CD11c(high)CD8 alpha(high)CD11b(low) dendritic cells in the lung. In this study, we investigated the effect of Flt3-L in a clinically relevant aeroallergen-induced asthma on the phenotypic expression of lung T cells. Balb/c mice were sensitized and challenged with cockroach antigen (CRA), and AHR to methacholine was established. These mice received three intraperitoneal injections of anti-CD25 antibody (PC61; 250 microg) and Flt3-L (3 microg) daily for 10 days. Cytokines and Ig levels in the serum were measured and differential bronchoalveolar lavage fluid (BALF) cell counts were examined. Flt3-L reversed AHR to methacholine to the control level. Flt3-L significantly decreased levels of BALF IL-5, IFN-gamma, eosinophilia and substantially increased IL-10 and the number of CD4(+)CD25(+) Forkhead winged helix transcription factor box P3 (Foxp3(+)) IL-10(+) T cells in the lung. Administration of PC61 antibody blocked the effect of Flt3-L and substantially increased AHR, eosinophilia, and BALF IL-5 and IFN-gamma levels, and decreased BALF IL-10 levels and the number of CD4(+)CD25(+)Foxp3(+)IL-10(+) T cells. Flt3-L significantly decreased CD62-L, but increased inducible costimulatory molecule and Foxp3 mRNA expression in the CD4(+)CD25(+) T cells isolated from lungs of Flt3-L-treated, CRA-sensitized mice compared to CRA-sensitized mice without Flt3-L treatment and PBS control group. Flt3-L significantly inhibited the effect of CRA sensitization and challenge to increase GATA3 expression in lung CD4(+)CD25(+) T cells. Collectively, these data suggest that the therapeutic effect of Flt3-L is mediated by increased density of naturally occurring CD4(+)CD25(+)Foxp3(+)IL-10(+)ICOS(+) T-regulatory cells in the lung. Flt3-L could be a therapeutic strategy for the management and prevention of allergic asthma.
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Affiliation(s)
- Halvor S McGee
- Department of Biomedical Sciences, Creighton University School of Medicine, Omaha, NE 68178, USA
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Coleman CA, Muller-Trutwin MC, Apetrei C, Pandrea I. T regulatory cells: aid or hindrance in the clearance of disease? J Cell Mol Med 2008; 11:1291-325. [PMID: 18205702 PMCID: PMC4401294 DOI: 10.1111/j.1582-4934.2007.00087.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
CD4+ CD25+ T regulatory cells (Tregs) are classified as a subset of T cells whose role is the suppression and regulation of immune responses to self and non-self. Since their discovery in the early 1970s, the role of CD4+ CD25+ Tregs in both autoimmune and infectious disease has continued to expand. This review exam-ines the recent advances on the role CD4+ CD25+ Tregs may be playing in various diseases regarding pro-gression or protection. In addition, advances made in the purification and manipulation of CD4+ CD25+ Tregs using new cell markers, techniques and antibodies are discussed. Ultimately, an overall understanding of the exact mechanism which CD4+ CD25+ Tregs implement during disease progression will enhance our ability to manipulate CD4+ CD25+ Tregs in a clinically beneficial manner.
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Affiliation(s)
- Clint A Coleman
- Department of Microbiology and Immunology, Tulane University Health Sciences Center, New Orleans, LA, USA
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Macrophages are mediators of gastritis in acute Helicobacter pylori infection in C57BL/6 mice. Infect Immun 2008; 76:2235-9. [PMID: 18332213 DOI: 10.1128/iai.01481-07] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Helicobacter pylori is the etiological agent of human chronic gastritis, a condition seen as a precursor to the development of gastrointestinal ulcers or gastric cancer. This study utilized the murine model of chronic H. pylori infection to characterize the role of macrophages in the induction of specific immune responses and gastritis and in the control of the bacterial burden following H. pylori infection and vaccination. Drug-loaded liposomes were injected intravenously to deplete macrophages from C57BL/6 mice, and effective removal of CD11b+ cells from the spleens and stomachs of mice was confirmed by immunofluorescence microscopy. Transient elimination of macrophages from C57BL/6 mice during the early period of infection reduced the gastric pathology induced by H. pylori SS1 but did not affect the bacterial load in the stomach. These data suggest that macrophages are important to the severity of gastric inflammation during H. pylori infection.
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van Driel IR, Ang DKY, Konz RF, Senices M, Young DA, Grusby MJ, Collins M, Dunussi-Joannopoulos K. Role of regulatory T cells in gastrointestinal inflammatory disease. J Gastroenterol Hepatol 2008; 23:171-7. [PMID: 18289352 DOI: 10.1111/j.1440-1746.2007.05278.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Regulatory T cells curb unwanted immune responses and regulate responses to microflora and it is now clear that regulatory T cells play an important role in a number of chronic inflammatory diseases of the gut. First, regulatory T cells are crucial in controlling immune responses to gastric autoantigens and thus preventing autoimmune gastritis and pernicious anemia. Second, regulatory T cells may modulate the response to Helicobacter pylori, thus affecting the ability of the immune system to clear the pathogen and mediate damage to the gastric mucosa. Finally, regulatory T cells play an important role in preventing damaging inflammatory responses to commensal organisms in the lower gut, thus guarding against inflammatory bowel diseases. In the present review, we examine the actions of regulatory T cells in the gut and conclude that further understanding of regulatory T cell biology may lead to new therapeutic approaches to chronic gastrointestinal disease.
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Affiliation(s)
- Ian R van Driel
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia.
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CD8+ T cells are associated with severe gastritis in Helicobacter pylori-infected mice in the absence of CD4+ T cells. Infect Immun 2007; 76:1289-97. [PMID: 18025102 DOI: 10.1128/iai.00779-07] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Helicobacter pylori infection results in the development of chronic gastritis, and CD4+ T cells are a major component of the gastric cellular infiltrate. To examine whether CD4+ T cells are important in initiating and maintaining H. pylori-induced gastritis, mice deficient in CD4+ T cells (B6.BM1.GK 1.5 mice [GK 1.5 mice]) were infected with H. pylori. We found that as in normal mice, H. pylori-specific antibodies, mostly of the immunoglobulin M isotype, developed in GK 1.5 mice but were unable to cure H. pylori infection. Further, while the stomachs of H. pylori-infected GK 1.5 mice were more heavily infiltrated with CD8+ T cells and B cells, mice deficient in both CD4+ and CD8+ T cells developed mild inflammation comparable to the level observed for C57BL/6 mice. These observations suggest that CD4+ T cells may play an important role in regulating or suppressing gastric CD8+ T cells which, in the absence of CD4+ T cells, may mediate more-severe disease. These studies have revealed a potentially important role for CD8+ T cells in the gastric disease resulting from H. pylori infection.
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Abstract
Surviving a given infection requires the generation of a controlled immune response. Failure to establish or restore homeostatic conditions during or following the onset of an infection can lead to tissue damage. Investigation of the immunoregulatory network that arises in response to the infectious process or that is induced by the pathogen itself should provide insight into therapeutic approaches for the control of infection and any subsequent immunopathology. In this Review, I discuss current hypotheses and points of polemic associated with the origin, mode of action and antigen specificity of the various populations of regulatory T cells that arise during infection.
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Algood HMS, Gallo-Romero J, Wilson KT, Peek RM, Cover TL. Host response to Helicobacter pylori infection before initiation of the adaptive immune response. ACTA ACUST UNITED AC 2007; 51:577-86. [PMID: 17919297 DOI: 10.1111/j.1574-695x.2007.00338.x] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Helicobacter pylori persistently colonizes the human stomach. In this study, immune responses to H. pylori that occur in the early stages of infection were investigated. Within the first 2 days after orogastric infection of mice with H. pylori, there was a transient infiltration of macrophages and neutrophils into the glandular stomach. By day 10 postinfection, the numbers of macrophages and neutrophils decreased to baseline levels. By 3 weeks postinfection, an adaptive immune response was detected, marked by gastric infiltration of T lymphocytes, macrophages, and neutrophils, as well as increased numbers of H. pylori-specific T cells, macrophages, and dendritic cells in paragastric lymph nodes. Neutrophil-attracting and macrophage-attracting chemokines were expressed at higher levels in the stomachs of H. pylori-infected mice than in the stomachs of uninfected mice. Increased expression of TNFalpha and IFNgamma (Th1-type inflammatory cytokines) and IL-17 (a Th17-type cytokine) was detected in the stomachs of H. pylori-infected mice, but increased expression of IL-4 (a Th2-type cytokine) was not detected. These data indicate that a transient gastric inflammatory response to H. pylori occurs within the first few days after infection, before the priming of T cells and initiation of an adaptive immune response. It is speculated that inappropriate waning of the innate immune response during early stages of infection may be a factor that contributes to H. pylori persistence.
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Affiliation(s)
- Holly M Scott Algood
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
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38
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Abstract
Helicobacter pylori infects almost 50% of the world population and is the major cause of gastroduodenal diseases. H. pylori colonizes the gastric mucosa, activates Toll-like and Nod-like receptors, and usually elicits a T helper 1 (Th1) type of immune response, fully polarized in peptic ulcer patients. Among several bacterial factors, the neutrophil-activating protein represents a key factor driving Th1 inflammation. A complex and fascinating balance between H. pylori and host factors takes part in the gastric niche and allows the majority of infected individuals to be without any symptom during their entire life. Novel insights into the innate and adaptive responses against H. pylori, dealing with regulatory T cells and cytokines, CTLA-4 molecule, cholesterol glucosylation, and immune evasion have been elucidated during the past year and are discussed for the development of an effective vaccine.
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Read S, Hogan TV, Zwar TD, Gleeson PA, Van Driel IR. Prevention of autoimmune gastritis in mice requires extra-thymic T-cell deletion and suppression by regulatory T cells. Gastroenterology 2007; 133:547-58. [PMID: 17603058 DOI: 10.1053/j.gastro.2007.05.050] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2006] [Accepted: 05/10/2007] [Indexed: 12/02/2022]
Abstract
BACKGROUND AND AIMS Autoimmune gastritis is one of the most common autoimmune diseases and is caused by a CD4(+) T-cell response to the gastric H(+)/K(+) ATPase encoded by Atp4a and Atp4b (H(+)/K(+) ATPase). Here, we have elucidated events that result in immunological tolerance to the H(+)/K(+) ATPase and thus the prevention of autoimmune gastritis. METHODS T cells from H(+)/K(+) ATPase-deficient mice and H(+)/K(+) ATPase-specific T-cell receptor transgenic mice were purified and transferred to wild-type (WT) or H(+)/K(+) ATPase-deficient recipients to assess the impact of exposure to antigen on pathogenicity. RESULTS The CD4(+) T-cell population from H(+)/K(+) ATPase-deficient mice was highly effective at inducing gastritis when compared with T cells from WT mice and, as a population, was comparatively resistant to the suppressive activity of regulatory T cells. Exposing T cells from H(+)/K(+) ATPase-deficient mice to H(+)/K(+) ATPase in WT mice decreased their ability to induce gastritis and resulted in a population that could be more easily suppressed by T(reg) cells. Transfer of clonotypic antigen-inexperienced H(+)/K(+) ATPase-specific T cells into WT mice resulted in extra-thymic clonal deletion. CONCLUSIONS Prevention of autoimmune gastritis requires the extra-thymic purging of highly autoaggressive H(+)/K(+) ATPase-specific T cells to produce a T-cell repertoire that is more susceptible to the suppressive activity of regulatory T cells. Taken together with recent published data describing the role of T-cell receptor signalling in the maintenance of regulatory T-cell populations, we propose that exposure of T cells to antigen in the periphery is able to both delete autoaggressive specificities and maintain regulatory T-cell activity, establishing a balance between pathogenicity and regulation.
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MESH Headings
- Adoptive Transfer
- Animals
- Autoantigens/genetics
- Autoantigens/immunology
- Autoimmune Diseases/enzymology
- Autoimmune Diseases/immunology
- Autoimmune Diseases/pathology
- Autoimmune Diseases/prevention & control
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/pathology
- CD4-Positive T-Lymphocytes/transplantation
- Cell Proliferation
- Disease Models, Animal
- Female
- Gastritis/enzymology
- Gastritis/immunology
- Gastritis/pathology
- Gastritis/prevention & control
- H(+)-K(+)-Exchanging ATPase/deficiency
- H(+)-K(+)-Exchanging ATPase/genetics
- H(+)-K(+)-Exchanging ATPase/immunology
- Immune Tolerance
- Interleukin-2 Receptor alpha Subunit/analysis
- Lymph Nodes/immunology
- Lymph Nodes/pathology
- Lymphocyte Depletion
- Mice
- Mice, Inbred BALB C
- Mice, Nude
- Mice, Transgenic
- Ovarian Diseases/enzymology
- Ovarian Diseases/immunology
- Ovarian Diseases/prevention & control
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/immunology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/pathology
- T-Lymphocytes, Regulatory/transplantation
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Affiliation(s)
- Simon Read
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
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40
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Wilson KT, Crabtree JE. Immunology of Helicobacter pylori: insights into the failure of the immune response and perspectives on vaccine studies. Gastroenterology 2007; 133:288-308. [PMID: 17631150 DOI: 10.1053/j.gastro.2007.05.008] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Accepted: 05/02/2007] [Indexed: 02/08/2023]
Abstract
Helicobacter pylori infects the stomach of half of the human population worldwide and causes chronic active gastritis, which can lead to peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. The host immune response to the infection is ineffective, because the bacterium persists and the inflammation continues for decades. Bacterial activation of epithelial cells, dendritic cells, monocytes, macrophages, and neutrophils leads to a T helper cell 1 type of adaptive response, but this remains inadequate. The host inflammatory response has a key functional role in disrupting acid homeostasis, which impacts directly on the colonization patterns of H pylori and thus the extent of gastritis. Many potential mechanisms for the failure of the host response have been postulated, and these include apoptosis of epithelial cells and macrophages, inadequate effector functions of macrophages and dendritic cells, VacA inhibition of T-cell function, and suppressive effects of regulatory T cells. Because of the extent of the disease burden, many strategies for prophylactic or therapeutic vaccines have been investigated. The goal of enhancing the host's ability to generate protective immunity has met with some success in animal models, but the efficacy of potential vaccines in humans remains to be demonstrated. Aspects of H pylori immunopathogenesis are reviewed and perspectives on the failure of the host immune response are discussed. Understanding the mechanisms of immune evasion could lead to new opportunities for enhancing eradication and prevention of infection and associated disease.
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Affiliation(s)
- Keith T Wilson
- Division of Gastroenterology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0252, USA
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41
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Svennerholm AM, Lundgren A. Progress in vaccine development against Helicobacter pylori. ACTA ACUST UNITED AC 2007; 50:146-56. [PMID: 17442014 DOI: 10.1111/j.1574-695x.2007.00237.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Based on the very high prevalence of diseases caused by Helicobacter pylori, particularly in the developing world, and the rapid emergence of antibiotic resistance among clinical isolates, there is a strong rationale for an effective vaccine against H. pylori. In this review we describe recent promising candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori, as well as studies to identify immune responses that are related to protection in experimental animals. We also describe identification of different types of immune responses that may be related to protection against symptoms based on comparisons of H. pylori-infected patients with duodenal ulcers or gastric cancer and asymptomatic carriers. We conclude that there is still a strong need to clarify the main protective immune mechanisms against H. pylori as well as to identify a cocktail of strong protective antigens, or recombinant bacterial strains that express such antigens, that could be administered by a regimen that gives rise to effective immune responses in humans.
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Affiliation(s)
- Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Institute of Biomedicine, Göteborg University, Göteborg, Sweden.
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42
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Tan MP, Kaparakis M, Galic M, Pedersen J, Pearse M, Wijburg OLC, Janssen PH, Strugnell RA. Chronic Helicobacter pylori infection does not significantly alter the microbiota of the murine stomach. Appl Environ Microbiol 2007; 73:1010-3. [PMID: 17142378 PMCID: PMC1800740 DOI: 10.1128/aem.01675-06] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2006] [Accepted: 11/20/2006] [Indexed: 12/12/2022] Open
Abstract
We examined the impact of Helicobacter pylori infection on the murine gastric microbiota by culture and terminal-restriction fragment length polymorphism and found that neither acute nor chronic H. pylori infection substantially affected the gastric microbial composition. Interestingly, the total H. pylori burden detected by real-time PCR was significantly higher than that revealed by viable counts, suggesting that the antigenic load sustaining H. pylori-induced gastritis could be considerably higher than previously believed.
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Affiliation(s)
- Mai Ping Tan
- Department of Microbiology and Immunology, University of Melbourne, Melbourne, Victoria 3010, Australia
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43
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Robinson K, Argent RH, Atherton JC. The inflammatory and immune response to Helicobacter pylori infection. Best Pract Res Clin Gastroenterol 2007; 21:237-59. [PMID: 17382275 DOI: 10.1016/j.bpg.2007.01.001] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Lifelong Helicobacter pylori infection and its associated gastric inflammation underlie peptic ulceration and gastric carcinogenesis. The immune and inflammatory responses to H. pylori are doubly responsible: gastric inflammation is the main mediator of pathology, and the immune and inflammatory response is ineffective, allowing lifelong bacterial persistence. However, despite inducing gastric inflammation, most infections do not cause disease, and bacterial, host and environmental factors determine individual disease risk. Although H. pylori avoids many innate immune receptors, specific virulence factors (including those encoded on the cag pathogenicity island) stimulate innate immunity to increase gastric inflammation and increase disease risk. An acquired T helper 1 response upregulates local immune effectors. The extent to which environmental factors (including parasite infection), host factors and H. pylori itself influence T-helper differentiation and regulatory T-cell responses remains controversial. Finally, effective vaccines have still not been developed: a better understanding of the immune response to H. pylori may help.
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Affiliation(s)
- Karen Robinson
- Wolfson Digestive Diseases Centre, University of Nottingham, C Floor, South Block, Queen's Medical Centre Campus, Nottingham University Hospital NHS Trust, Nottingham NG7 2UH, UK.
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44
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McKinley L, Logar AJ, McAllister F, Zheng M, Steele C, Kolls JK. Regulatory T cells dampen pulmonary inflammation and lung injury in an animal model of pneumocystis pneumonia. THE JOURNAL OF IMMUNOLOGY 2006; 177:6215-26. [PMID: 17056551 PMCID: PMC3912571 DOI: 10.4049/jimmunol.177.9.6215] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
CD4+CD25+FoxP3+ regulatory T cells are decreased in patients infected with HIV and have been shown to be critical in mediating Ag tolerance in the lung. Because a subset of Pneumocystis-infected individuals develop substantial lung injury, which can be modeled in immune reconstituted scid mice, we used mouse models of Pneumocystis carinii to investigate the role of regulatory T cells in opportunistic infection and immune reconstitution. In this study, we show that CD4+CD25+FoxP3+ cells are part of the host response to Pneumocystis in CD4+ T cell-intact mice. Moreover, lung injury and proinflammatory Th1 and Th2 cytokine levels in the bronchoalveolar lavage fluid and lung homogenate were increased following CD4+CD25- immune reconstitution in Pneumocystis-infected SCID mice but not in CD4+CD25+ T cell-reconstituted animals. The ability of CD4+CD25+ T cells to control inflammation and injury during the course of Pneumocystis was confirmed by treatment of wild-type C57BL/6 mice with anti-CD25 mAb. These data show that CD4+CD25+ T cells control pulmonary inflammation and lung injury associated with Pneumocystis infection both in the setting of immune reconstitution as well as new acquisition of infection.
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Affiliation(s)
| | | | | | | | | | - Jay K. Kolls
- Address correspondence and reprint requests to Dr. Jay K. Kolls, Children’s Hospital of Pittsburgh, Suite 3765, 3705 Fifth Avenue, Pittsburgh, PA 15213.
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