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Brown JW, Lin X, Nicolazzi GA, Nguyen T, Radyk MD, Burclaff J, Mills JC. Cathartocytosis: How Cells Jettison Unwanted Material as They Reprogram. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598489. [PMID: 38915707 PMCID: PMC11195262 DOI: 10.1101/2024.06.11.598489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Injury can cause differentiated cells to undergo massive reprogramming to become proliferative to repair tissue via a cellular program called paligenosis. Gastric digestive-enzyme-secreting chief cells use paligenosis to reprogram into progenitor-like Spasmolytic-Polypeptide Expressing Metaplasia (SPEM) cells. Stage 1 of paligenosis is to downscale mature cell architecture via a process involving lysosomes. Here, we noticed that sulfated glycoproteins (which are metaplasia and cancer markers in mice and humans) were not digested during paligenosis but excreted into the gland lumen. Various genetic and pharmacological approaches showed that endoplasmic reticulum membranes and secretory granule cargo were also excreted and that the process proceeded in parallel with, but was independent lysosomal activity. 3-dimensional light and electron-microscopy demonstrated that excretion occurred via unique, complex, multi-chambered invaginations of the apical plasma membrane. As this lysosome-independent cell cleansing process does not seem to have been priorly described, we termed it "cathartocytosis". Cathartocytosis allows a cell to rapidly eject excess material (likely in times of extreme stress such as are induced by paligenosis) without waiting for autophagic and lysosomal digestion. We speculate the ejection of sulfated glycoproteins (likely mucins) would aid in downscaling and might also help bind and flush pathogens (like H pylori which causes SPEM) away from tissue.
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Li S, Zhao W, Xia L, Kong L, Yang L. How Long Will It Take to Launch an Effective Helicobacter pylori Vaccine for Humans? Infect Drug Resist 2023; 16:3787-3805. [PMID: 37342435 PMCID: PMC10278649 DOI: 10.2147/idr.s412361] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023] Open
Abstract
Helicobacter pylori infection often occurs in early childhood, and can last a lifetime if not treated with medication. H. pylori infection can also cause a variety of stomach diseases, which can only be treated with a combination of antibiotics. Combinations of antibiotics can cure H. pylori infection, but it is easy to relapse and develop drug resistance. Therefore, a vaccine is a promising strategy for prevention and therapy for the infection of H. pylori. After decades of research and development, there has been no appearance of any H. pylori vaccine reaching the market, unfortunately. This review summarizes the aspects of candidate antigens, immunoadjuvants, and delivery systems in the long journey of H. pylori vaccine research, and also introduces some clinical trials that have displayed encouraging or depressing results. Possible reasons for the inability of an H. pylori vaccine to be available over the counter are cautiously discussed and some propositions for the future of H. pylori vaccines are outlined.
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Affiliation(s)
- Songhui Li
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009People’s Republic of China
| | - Wenfeng Zhao
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009People’s Republic of China
| | - Lei Xia
- Bloomage Biotechnology Corporation Limited, Jinan, People’s Republic of China
| | - Lingyi Kong
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009People’s Republic of China
| | - Lei Yang
- Jiangsu Key Laboratory of Bioactive Natural Product Research and State Key Laboratory of Natural Medicines, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, 210009People’s Republic of China
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Das KK, Brown JW. 3'-sulfated Lewis A/C: An oncofetal epitope associated with metaplastic and oncogenic plasticity of the gastrointestinal foregut. Front Cell Dev Biol 2023; 11:1089028. [PMID: 36866273 PMCID: PMC9971977 DOI: 10.3389/fcell.2023.1089028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 01/10/2023] [Indexed: 02/16/2023] Open
Abstract
Metaplasia, dysplasia, and cancer arise from normal epithelia via a plastic cellular transformation, typically in the setting of chronic inflammation. Such transformations are the focus of numerous studies that strive to identify the changes in RNA/Protein expression that drive such plasticity along with the contributions from the mesenchyme and immune cells. However, despite being widely utilized clinically as biomarkers for such transitions, the role of glycosylation epitopes is understudied in this context. Here, we explore 3'-Sulfo-Lewis A/C, a clinically validated biomarker for high-risk metaplasia and cancer throughout the gastrointestinal foregut: esophagus, stomach, and pancreas. We discuss the clinical correlation of sulfomucin expression with metaplastic and oncogenic transformation, as well as its synthesis, intracellular and extracellular receptors and suggest potential roles for 3'-Sulfo-Lewis A/C in contributing to and maintaining these malignant cellular transformations.
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Affiliation(s)
- Koushik K Das
- Division of Gastroenterology, Department of Medicine, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
| | - Jeffrey W Brown
- Division of Gastroenterology, Department of Medicine, Washington University in St. Louis, School of Medicine, St. Louis, MO, United States
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Bereznicka A, Mikolajczyk K, Czerwinski M, Kaczmarek R. Microbial lectome versus host glycolipidome: How pathogens exploit glycosphingolipids to invade, dupe or kill. Front Microbiol 2022; 13:958653. [PMID: 36060781 PMCID: PMC9437549 DOI: 10.3389/fmicb.2022.958653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/22/2022] [Indexed: 11/13/2022] Open
Abstract
Glycosphingolipids (GSLs) are ubiquitous components of the cell membranes, found across several kingdoms of life, from bacteria to mammals, including humans. GSLs are a subclass of major glycolipids occurring in animal lipid membranes in clusters named “lipid rafts.” The most crucial functions of GSLs include signal transduction and regulation as well as participation in cell proliferation. Despite the mainstream view that pathogens rely on protein–protein interactions to survive and thrive in their hosts, many also target the host lipids. In particular, multiple pathogens produce adhesion molecules or toxins that bind GSLs. Attachment of pathogens to cell surface receptors is the initial step in infections. Many mammalian pathogens have evolved to recognize GSL-derived receptors. Animal glycosphingolipidomes consist of multiple types of GSLs differing in terminal glycan and ceramide structures in a cell or tissue-specific manner. Interspecies differences in GSLs dictate host specificity as well as cell and tissue tropisms. Evolutionary pressure exerted by pathogens on their hosts drives changes in cell surface glycoconjugates, including GSLs, and has produced a vast number of molecules and interaction mechanisms. Despite that abundance, the role of GSLs as pathogen receptors has been largely overlooked or only cursorily discussed. In this review, we take a closer look at GSLs and their role in the recognition, cellular entry, and toxicity of multiple bacterial, viral and fungal pathogens.
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Brown JW, Das KK, Kalas V, Das KM, Mills JC. mAb Das-1 recognizes 3'-Sulfated Lewis A/C, which is aberrantly expressed during metaplastic and oncogenic transformation of several gastrointestinal Epithelia. PLoS One 2021; 16:e0261082. [PMID: 34910746 PMCID: PMC8673611 DOI: 10.1371/journal.pone.0261082] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 11/23/2021] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Multiple previous studies have shown the monoclonal antibody Das-1 (formerly called 7E12H12) is specifically reactive towards metaplastic and carcinomatous lesions in multiple organs of the gastrointestinal system (e.g. Barrett's esophagus, intestinal-type metaplasia of the stomach, gastric adenocarcinoma, high-grade pancreatic intraepithelial neoplasm, and pancreatic ductal adenocarcinoma) as well as in other organs (bladder and lung carcinomas). Beyond being a useful biomarker in tissue, mAb Das-1 has recently proven to be more accurate than current paradigms for identifying cysts harboring advanced neoplasia. Though this antibody has been used extensively for clinical, basic science, and translational applications for decades, its epitope has remained elusive. METHODS In this study, we chemically deglycosylated a standard source of antigen, which resulted in near complete loss of the signal as measured by western blot analysis. The epitope recognized by mAb Das-1 was determined by affinity to a comprehensive glycan array and validated by inhibition of a direct ELISA. RESULTS The epitope recognized by mAb Das-1 is 3'-Sulfo-Lewis A/C (3'-Sulfo-LeA/C). 3'-Sulfo-LeA/C is broadly reexpressed across numerous GI epithelia and elsewhere during metaplastic and carcinomatous transformation. DISCUSSION 3'-Sulfo-LeA/C is a clinically important antigen that can be detected both intracellularly in tissue using immunohistochemistry and extracellularly in cyst fluid and serum by ELISA. The results open new avenues for tumorigenic risk stratification of various gastrointestinal lesions.
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Affiliation(s)
- Jeffrey W. Brown
- Division of Gastroenterology, Department of Medicine, Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
| | - Koushik K. Das
- Division of Gastroenterology, Department of Medicine, Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
| | - Vasilios Kalas
- Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
- Physician Scientist Training Program, Department of Medicine, McGaw Medical Center of Northwestern University, Chicago, Illinois, United States of America
| | - Kiron M. Das
- Division of Gastroenterology, Rutgers Robert Wood Johnson Medical School, New Brunswick, New Jersey, United States of America
| | - Jason C. Mills
- Division of Gastroenterology, Department of Medicine, Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
- Department of Pathology and Immunology, Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
- Department of Developmental Biology, Washington University in St. Louis, School of Medicine, St. Louis, Missouri, United States of America
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Von Mentzer A, Zalem D, Chrienova Z, Teneberg S. Colonization factor CS30 from enterotoxigenic Escherichia coli binds to sulfatide in human and porcine small intestine. Virulence 2021; 11:381-390. [PMID: 32245341 PMCID: PMC7161690 DOI: 10.1080/21505594.2020.1749497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability to adhere via colonization factors to specific receptors located on the intestinal mucosa is a key virulence factor in enterotoxigenic Escherichia coli (ETEC) pathogenesis. Here, the potential glycosphingolipid receptors of the novel human ETEC colonization factor CS30 were examined by binding of CS30-expressing bacteria to glycosphingolipids on thin-layer chromatograms. We thereby found a highly specific binding of CS30-expressing bacteria to a fast-migrating acid glycosphingolipid of human and porcine small intestine, while no binding was obtained with a mutant ETEC strain unable to express CS30 fimbriae. The CS30 binding glycosphingolipid from human small intestine was isolated and characterized by mass spectrometry as sulfatide (SO3-3Galβ1Cer). Comparative binding studies using sulfatides with different ceramide compositions gave a preferential binding of CS30 to sulfatide with d18:1-h24:0 ceramide. This ceramide species of sulfatide was also isolated from human small intestine and characterized by mass spectrometry and antibody binding. These studies implicate sulfatide as candidate receptor for mediating attachment of CS30-fimbriated ETEC to human and porcine small intestinal cells. Our findings may be a basis for designing receptor saccharide analogues for inhibition of the intestinal adhesion of CS30-expressing E. coli.
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Affiliation(s)
- Astrid Von Mentzer
- Department of Microbiology and Immunology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Wellcome Sanger Institute: Parasites and Microbes Programme, Hinxton, UK
| | - Dani Zalem
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Zofia Chrienova
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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Banga Ndzouboukou JL, Lei Q, Ullah N, Zhang Y, Hao L, Fan X. Helicobacter pylori adhesins: HpaA a potential antigen in experimental vaccines for H. pylori. Helicobacter 2021; 26:e12758. [PMID: 33259676 DOI: 10.1111/hel.12758] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/14/2020] [Accepted: 09/01/2020] [Indexed: 12/19/2022]
Abstract
BACKGROUND Helicobacter pylori is a gram-negative bacterium involved in many gastric pathologies such as ulcers and cancers. Although the treatment for this infection has existed for several years, the development of a vaccine is nevertheless necessary to reduce the severe forms of the disease. For more than three decades, many advances have been made particularly in the understanding of virulence factors as well as the pathogenesis of gastric diseases caused by H. pylori. Among these key virulence factors, specific antigens have been identified: Urease, Vacuolating cytotoxin A (VacA), Cytotoxin-associated gene A (CagA), Blood group antigen-binding adhesin (BabA), H. pylori adhesin A (HpaA), and others. OBJECTIVES This review will focus on H. pylori adhesins, in particular, on HpaA and on the current knowledge of H. pylori vaccines. METHODS All of the information included in this review was retrieved from published studies on H. pylori adhesins in H. pylori infections. RESULTS These proteins, used in their native or recombinant forms, induce protection against H. pylori in experimental animal models. CONCLUSION H. pylori adhesins are known to be promising candidate vaccines against H. pylori. Future research should be carried out on adhesins, in particular, on HpaA.
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Affiliation(s)
- Jo-Lewis Banga Ndzouboukou
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Lei
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nadeem Ullah
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yandi Zhang
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Hao
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xionglin Fan
- Department of Pathogen Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Kira JI, Isobe N. Helicobacter pylori infection and demyelinating disease of the central nervous system. J Neuroimmunol 2019; 329:14-19. [DOI: 10.1016/j.jneuroim.2018.06.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/28/2018] [Indexed: 12/29/2022]
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Carbohydrate-Dependent and Antimicrobial Peptide Defence Mechanisms Against Helicobacter pylori Infections. Curr Top Microbiol Immunol 2019; 421:179-207. [PMID: 31123890 DOI: 10.1007/978-3-030-15138-6_8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The human stomach is a harsh and fluctuating environment for bacteria with hazards such as gastric acid and flow through of gastric contents into the intestine. H. pylori gains admission to a stable niche with nutrient access from exudates when attached to the epithelial cells under the mucus layer, whereof adherence to glycolipids and other factors provides stable and intimate attachment. To reach this niche, H. pylori must overcome mucosal defence mechanisms including the continuously secreted mucus layer, which provides several layers of defence: (1) mucins in the mucus layer can bind H. pylori and transport it away from the gastric niche with the gastric emptying, (2) mucins can inhibit H. pylori growth, both via glycans that can have antibiotic like function and via an aggregation-dependent mechanism, (3) antimicrobial peptides (AMPs) have antimicrobial activity and are retained in a strategic position in the mucus layer and (4) underneath the mucus layer, the membrane-bound mucins provide a second barrier, and can function as releasable decoys. Many of these functions are dependent on H. pylori interactions with host glycan structures, and both the host glycosylation and concentration of antimicrobial peptides change with infection and inflammation, making these interactions dynamic. Here, we review our current understanding of mucin glycan and antimicrobial peptide-dependent host defence mechanisms against H. pylori infection.
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Benktander J, Barone A, Johansson MM, Teneberg S. Helicobacter pylori SabA binding gangliosides of human stomach. Virulence 2018; 9:738-751. [PMID: 29473478 PMCID: PMC5955481 DOI: 10.1080/21505594.2018.1440171] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/17/2018] [Accepted: 02/05/2018] [Indexed: 12/11/2022] Open
Abstract
Adhesion of Helicobacter pylori to the gastric mucosa is a prerequisite for the pathogenesis of H. pylori related diseases. In this study, we investigated the ganglioside composition of human stomach as the target for attachment mediated by H. pylori SabA (sialic acid binding adhesin). Acid glycosphingolipids were isolated from human stomach and separated into subfractions, which were characterized by mass spectrometry and by binding of antibodies, bacteria, and Solanum tuberosum lectin. H. pylori SabA binding gangliosides were characterized as Neu5Acα3-neolactohexaosylceramide and Neu5Acα3-neolactooctaosylceramide, while the other acid human stomach glycosphingolipids characterized (sulfatide and the gangliosides GM3, GD3, GM1, Neu5Acα3-neolactotetraosylceramide, GD1a and GD1b) were not recognized by the bacteria. Defining H. pylori binding glycosphingolipids of the human gastric mucosa will be useful to specifically target this microbe-host interaction for therapeutic intervention.
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Affiliation(s)
- John Benktander
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Angela Barone
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Miralda Madar Johansson
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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Inhibitory effects of rHP-NAP IgY against Helicobacter pylori attachment to AGS cell line. Microb Pathog 2016; 97:231-5. [PMID: 27265677 DOI: 10.1016/j.micpath.2016.06.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 05/30/2016] [Accepted: 06/01/2016] [Indexed: 01/28/2023]
Abstract
Helicobacter pylori is a major human pathogen related to gastric adenocarcinoma and gastroduodenal diseases. Treatment of H. pylori infections is complicated by the rise of antibiotic resistance, necessitating investigation of alternative therapies. One such alternative is passive immunization by oral administration of antibacterial immunoglobulin. In the present study, chicken immunoglobulin (IgY) was used for passive immunotherapy against a major virulence factor of H. pylori, namely recombinant HP-Nap protein. Recombinant HP-Nap was prepared and used to immunize hens. IgY was purified from the eggs by polyethylene glycol precipitation method with a total IgY-HP-NAP yield of 30 mg per egg. The inhibitory effect of specific IgY on H. pylori attachment was investigated in AGS cell line infected by the bacteria. The results demonstrate the potent effect of IgY- HP-NAP in inhibition of H. pylori attachment to the AGS cells.
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Shan W, Kung HF, Ge R. Comparison of Iron-Binding Ability Between Thr70-NapA and Ser70-NapA of Helicobacter pylori. Helicobacter 2016; 21:192-200. [PMID: 26347349 DOI: 10.1111/hel.12266] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND The neutrophil-activating protein (NapA) of Helicobacter pylori (H. pylori), with DNA-binding and iron seizing properties, is a fundamental virulence factor involved in H. pylori-related diseases. Compared with Ser70-NapA strain, Thr70-NapA strain is more intimately correlated with iron-deficiency anemia. METHODS To investigate whether two types of proteins differ in iron-binding ability, mutated Thr70-NapA and Ser70-NapA strains were established. Isothermal titration calorimetry (ITC) method was conducted to measure the binding between the NapA protein and Fe(2+) . The structural changes of NapA protein were also tested during iron interaction by fast protein liquid chromatography (FPLC) and circular dichroism (CD) methods. DNA-binding assay was performed for evaluate the affinity of both mutated and wild types of NapA with DNA. RESULTS Mutated Thr70-NapA had higher iron-binding ability than wild Ser70-NapA. The structural stability of Thr70-NapA was disrupted and became more active along with the rising concentration of Fe(2+) , whereas no similar association was observed between Ser70-NapA and Fe(2+) level. When the iron/protein molar ratio ranged from 10 to 20, both Ser70-NapA and Thr70-NapA displayed weaker DNA-binding ability. CONCLUSIONS Thr70-NapA has much stronger ability to sequester ferrous ion compared with Ser70-NapA in H. pylori. In addition, the DNA-binding property of NapA is dependent upon the Fe(2+) concentration.
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Affiliation(s)
- Weiran Shan
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Hsiang-Fu Kung
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Ruiguang Ge
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-Sen University, Guangzhou, China
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Allam B, Pales Espinosa E. Bivalve immunity and response to infections: Are we looking at the right place? FISH & SHELLFISH IMMUNOLOGY 2016; 53:4-12. [PMID: 27004953 DOI: 10.1016/j.fsi.2016.03.037] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/17/2016] [Accepted: 03/17/2016] [Indexed: 06/05/2023]
Abstract
Significant progress has been made in the understanding of cellular and molecular mediators of immunity in invertebrates in general and bivalve mollusks in particular. Despite this information, there is a lack of understanding of factors affecting animal resistance and specific responses to infections. This in part results from limited consideration of the spatial (and to some extent temporal) heterogeneity of immune responses and very limited information on host-pathogen (and microbes in general) interactions at initial encounter/colonization sites. Of great concern is the fact that most studies on molluscan immunity focus on the circulating hemocytes and the humoral defense factors in the plasma while most relevant host-microbe interactions occur at mucosal interfaces. This paper summarizes information available on the contrasting value of information available on focal and systemic immune responses in infected bivalves, and highlights the role of mucosal immune factors in host-pathogen interactions. Available information underlines the diversity of immune effectors at molluscan mucosal interfaces and highlights the tailored immune response to pathogen stimuli. This context raises fascinating basic research questions around host-microbe crosstalk and feedback controls of these interactions and may lead to novel disease mitigation strategies and improve the assessment of resistant crops or the screening of probiotic candidates.
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Affiliation(s)
- Bassem Allam
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, United States.
| | - Emmanuelle Pales Espinosa
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, United States
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Kao CY, Sheu BS, Wu JJ. Helicobacter pylori infection: An overview of bacterial virulence factors and pathogenesis. Biomed J 2016; 39:14-23. [PMID: 27105595 PMCID: PMC6138426 DOI: 10.1016/j.bj.2015.06.002] [Citation(s) in RCA: 252] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/08/2015] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori pathogenesis and disease outcomes are mediated by a complex interplay between bacterial virulence factors, host, and environmental factors. After H. pylori enters the host stomach, four steps are critical for bacteria to establish successful colonization, persistent infection, and disease pathogenesis: (1) Survival in the acidic stomach; (2) movement toward epithelium cells by flagella-mediated motility; (3) attachment to host cells by adhesins/receptors interaction; (4) causing tissue damage by toxin release. Over the past 20 years, the understanding of H. pylori pathogenesis has been improved by studies focusing on the host and bacterial factors through epidemiology researches and molecular mechanism investigations. These include studies identifying the roles of novel virulence factors and their association with different disease outcomes, especially the bacterial adhesins, cag pathogenicity island, and vacuolating cytotoxin. Recently, the development of large-scale screening methods, including proteomic, and transcriptomic tools, has been used to determine the complex gene regulatory networks in H. pylori. In addition, a more available complete genomic database of H. pylori strains isolated from patients with different gastrointestinal diseases worldwide is helpful to characterize this bacterium. This review highlights the key findings of H. pylori virulence factors reported over the past 20 years.
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Affiliation(s)
- Cheng-Yen Kao
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Bor-Shyang Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Medical Laboratory Science and Biotechnology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; Center of Infectious Disease and Signaling Research, National Cheng Kung University, Tainan, Taiwan; Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan.
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15
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Sanchuki HBS, Valdameri G, Moure VR, Oliveira MA, Pedrosa FO, Souza EM, Korolik V, Huergo LF. Purification of the Campylobacter jejuni Dps protein assisted by its high melting temperature. Protein Expr Purif 2015; 111:105-10. [PMID: 25707373 DOI: 10.1016/j.pep.2014.12.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 11/17/2022]
Abstract
Dps proteins (DNA binding protein from starved cell) form a distinct group within the ferritin superfamily. All Dps members are composed of 12 identical subunits that assemble into a conserved spherical protein shell. Dps oxidize Fe(2+) in a conserved ferroxidase center located at the interface between monomers, the product of the reaction Fe(3+), is then stored inside the protein shell in the form of non-reactive insoluble Fe2O3. The Campylobacter jejuni Dps (CjDps) has been reported to play a plethora of functions, such as DNA binding and protection, iron storage, survival in response to hydrogen peroxide and sulfatide binding. CjDps is also important during biofilm formation and caecal colonization in poultry. In order to facilitate in vitro characterisation of CjDps, it is important to have a simple and reproducible protocol for protein purification. Here we report an observation that CjDps has an unusual high melting temperature. We exploited this property for protein purification by introducing a thermal treatment step which allowed achieving homogeneity by using only two chromatographic steps. Gel filtration chromatography, circular dichroism, mass spectrometry, DNA-binding and iron oxidation analysis confirmed that the CjDps structure and function were unaffected.
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Affiliation(s)
- Heloisa B S Sanchuki
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Glaucio Valdameri
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Vivian R Moure
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Marco A Oliveira
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Fábio O Pedrosa
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Emanuel M Souza
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil
| | - Victoria Korolik
- Institute for Glycomics, Griffith University, Gold Coast Campus, Queensland, Australia
| | - Luciano F Huergo
- Instituto Nacional de Ciência e Tecnologia da Fixação Biológica de Nitrogênio, Departamento de Bioquímica e Biologia Molecular, UFPR Curitiba, PR, Brazil.
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16
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Structures and metal-binding properties of Helicobacter pylori neutrophil-activating protein with a di-nuclear ferroxidase center. Biomolecules 2014; 4:600-15. [PMID: 24971723 PMCID: PMC4192664 DOI: 10.3390/biom4030600] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 06/03/2014] [Accepted: 06/04/2014] [Indexed: 01/24/2023] Open
Abstract
Helicobacter pylori causes severe diseases, such as chronic gastritis, peptic ulcers, and stomach cancers. H. pylori neutrophil-activating protein (HP-NAP) is an iron storage protein that forms a dodecameric shell, promotes the adhesion of neutrophils to endothelial cells, and induces the production of reactive oxygen radicals. HP-NAP belongs to the DNA-protecting proteins under starved conditions (Dps) family, which has significant structural similarities to the dodecameric ferritin family. The crystal structures of the apo form and metal-ion bound forms, such as iron, zinc, and cadmium, of HP-NAP have been determined. This review focused on the structures and metal-binding properties of HP-NAP. These metal ions bind at the di-nuclear ferroxidase center (FOC) by different coordinating patterns. In comparison with the apo structure, metal loading causes a series of conformational changes in conserved residues among HP-NAP and Dps proteins (Trp26, Asp52, and Glu56) at the FOC. HP-NAP forms a spherical dodecamer with 23 symmetry including two kinds of pores. Metal ions have been identified around one of the pores; therefore, the negatively-charged pore is suitable for the passage of metal ions.
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Nishiyama K, Kawanabe A, Miyauchi H, Abe F, Tsubokawa D, Ishihara K, Yamamoto Y, Mukai T. Evaluation of bifidobacterial adhesion to acidic sugar chains of porcine colonic mucins. Biosci Biotechnol Biochem 2014; 78:1444-51. [PMID: 25130751 DOI: 10.1080/09168451.2014.918491] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The aim of this study was to assess the adhesion of Bifidobacterium strains to acidic carbohydrate moieties of porcine colonic mucin. Mucins were extracted and purified via gel filtration chromatography followed by density-gradient ultracentrifugation. The presence of sulfated and sialylated carbohydrates in mucins was shown by enzyme-linked immunosorbent assays using PGM34 and HMC31 monoclonal antibodies (mAbs), respectively. Adhesion of Bifidobacterium strains to mucin preparations was markedly affected by the degree of purification. In eight of 22 strains, we observed increased adhesion to mucin preparations purified by ultracentrifugation. Moreover, in some of these eight strains, adhesion to mucin was reduced by pretreatment with sulfatase and/or sialidase, and competitively inhibited by pretreatment with PGM34 and/or HCM31 mAbs. Our results showed that some Bifidobacterium strains adhered to sulfo- and/or sialomucin and were able to recognize carbohydrate structures of the mAbs epitopes.
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Affiliation(s)
- Keita Nishiyama
- a Department of Animal Science , Kitasato University School of Veterinary Medicine , Towada , Japan
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18
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Fu HW. Helicobacter pylori neutrophil-activating protein: From molecular pathogenesis to clinical applications. World J Gastroenterol 2014; 20:5294-5301. [PMID: 24833859 PMCID: PMC4017044 DOI: 10.3748/wjg.v20.i18.5294] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 12/02/2013] [Accepted: 01/06/2014] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) neutrophil-activating protein (HP-NAP) was originally identified as a virulence factor of H. pylori for its ability to activate neutrophils to generate respiratory burst by releasing reactive oxygen species. Later on, HP-NAP was also found to be involved in the protection of H. pylori from DNA damage, supporting the survival of H. pylori under oxidative stress. This protein is highly conserved and expressed by virtually all clinical isolates of H. pylori. The majority of patients infected with H. pylori produced antibodies specific for HP-NAP, suggesting its important role in immunity. In addition to acting as a pathogenic factor by activating the innate immunity through a wide range of human leukocytes, including neutrophils, monocytes, and mast cells, HP-NAP also mediates adaptive immunity through the induction of T helper cell type I responses. The pro-inflammatory and immunomodulatory properties of HP-NAP not only make it play an important role in disease pathogenesis but also make it a potential candidate for clinical use. Even though there is no convincing evidence to link HP-NAP to a disease outcome, recent findings supporting the pathogenic role of HP-NAP will be reviewed. In addition, the potential clinical applications of HP-NAP in vaccine development, clinical diagnosis, and drug development will be discussed.
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19
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Nishiyama K, Ochiai A, Tsubokawa D, Ishihara K, Yamamoto Y, Mukai T. Identification and characterization of sulfated carbohydrate-binding protein from Lactobacillus reuteri. PLoS One 2013; 8:e83703. [PMID: 24391811 PMCID: PMC3877078 DOI: 10.1371/journal.pone.0083703] [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: 09/17/2013] [Accepted: 11/06/2013] [Indexed: 02/07/2023] Open
Abstract
We previously purified a putative sulfated-galactosylceramide (sulfatide)-binding protein with a molecular weight of 47 kDa from the cell surface of Lactobacillus reuteri JCM1081. The aim of this study was to identify the 47-kDa protein, examine its binding to sulfated glycolipids and mucins, and evaluate its role in bacterial adhesion to mucosal surfaces. By cloning and sequencing analysis, the 47-kDa protein was identified as elongation factor-Tu (EF-Tu). Adhesion properties were examined using 6×Histidine-fused EF-Tu (His6-EF-Tu). Surface plasmon resonance analysis demonstrated pH-dependent binding of His6-EF-Tu to sulfated glycolipids, but not to neutral or sialylated glycolipids, suggesting that a sulfated galactose residue was responsible for EF-Tu binding. Furthermore, His6-EF-Tu was found to bind to porcine gastric mucin (PGM) by enzyme-linked immunosorbent assay. Binding was markedly reduced by sulfatase treatment of PGM and in the presence of acidic and desialylated oligosaccharide fractions containing sulfated carbohydrate residues prepared from PGM, demonstrating that sulfated carbohydrate moieties mediated binding. Histochemical staining revealed similar localization of His6-EF-Tu and high iron diamine staining in porcine mucosa. These results indicated that EF-Tu bound PGM via sulfated carbohydrate moieties. To characterize the contribution of EF-Tu to the interaction between bacterial cells and PGM, we tested whether anti-EF-Tu antibodies could inhibit the interaction. Binding of L. reuteri JCM1081 to PGM was significantly blocked in a concentration-dependent matter, demonstrating the involvement of EF-Tu in bacterial adhesion. In conclusion, the present results demonstrated, for the first time, that EF-Tu bound sulfated carbohydrate moieties of sulfated glycolipids and sulfomucin, thereby promoting adhesion of L. reuteri to mucosal surfaces.
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Affiliation(s)
- Keita Nishiyama
- Department of Animal Science, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - Ayaka Ochiai
- Department of Animal Science, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - Daigo Tsubokawa
- Department of Parasitology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan
| | - Kazuhiko Ishihara
- Graduate School of Medical Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Yuji Yamamoto
- Department of Animal Science, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
| | - Takao Mukai
- Department of Animal Science, Kitasato University School of Veterinary Medicine, Towada, Aomori, Japan
- * E-mail:
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20
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Up-regulation of neutrophil activating protein in Helicobacter pylori under high-salt stress: structural and phylogenetic comparison with bacterial iron-binding ferritins. Biochimie 2013; 95:1136-45. [PMID: 23352965 DOI: 10.1016/j.biochi.2012.12.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 12/30/2012] [Indexed: 02/08/2023]
Abstract
It is generally accepted that most gastrointestinal diseases are probably caused by the bacterial pathogen Helicobacter pylori (H. pylori). In this study we have focused on the comparison of protein expression profiles of H. pylori grown under normal and high-salt conditions by a proteomics approach. We have identified about 190 proteins whose expression levels changed after growth at high salt concentration. Among these proteins, neutrophil-activating protein (NapA) was found to be consistently up-regulated under osmotic stress brought by high salts. We have investigated the effect of high salt on secondary and tertiary structures of NapA by circular dichroism spectroscopy followed by analytical ultracentrifugation to monitor the change of quaternary structure of recombinant NapA with increasing salt concentration. The loss of iron-binding activity of NapA coupled with noticeable energetic variation in protein association of NapA as revealed by isothermal titration calorimetry was found under high salt condition. The phylogenetic tree analysis based on sequence comparison of 16 protein sequences encompassing NapA proteins and ferritin of H. pylori and other prokaryotic organisms pointed to the fact that all H. pylori NapA proteins of human origin are more homologous to NapA of Helicobacter genus than to other bacterial NapA. Based on computer modeling, NapA proteins from H. pylori of human isolates are found more similar to ferritin from H. pylori than to NapA from other species of bacteria. Taken together, these results suggested that divergent evolution of NapA and ferritin possessing dissimilar and diverse sequences follows a path distinct from that of convergent evolution of NapA and ferritin with similar dual functionality of iron-binding and ferroxidase activities.
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21
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Iankov ID, Penheiter AR, Carlson SK, Galanis E. Development of monoclonal antibody-based immunoassays for detection of Helicobacter pylori neutrophil-activating protein. J Immunol Methods 2012; 384:1-9. [PMID: 22750540 DOI: 10.1016/j.jim.2012.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 06/19/2012] [Accepted: 06/20/2012] [Indexed: 12/15/2022]
Abstract
Neutrophil-activating protein (NAP) is a major virulence factor expressed by Helicobacter pylori isolates associated with severe chronic gastroduodenal inflammation and peptic ulcers. NAP is one of the main protective antigens and a target for vaccine development against Helicobacter infection. In addition, NAP is a potent immune stimulator with potential application as a general vaccine adjuvant and in treatment of allergic diseases and cancer immunotherapy. NAP-specific immunoassays are needed for both H. pylori diagnostics and characterization of NAP-based vaccines and immunomodulatory preparations. We generated a panel of NAP-specific monoclonal antibodies (MAbs) by immunization of BALB/c mice with synthetic NAP peptides. The antibody reactivity against recombinant or native NAP antigen was characterized by enzyme-linked immunosorbent assay (ELISA), immunoblotting and immunofluorescence. A sensitive capture ELISA was developed using MAbs 23C8 and 16F4 (directed against different NAP epitopes) for detection of native or measles virus (MV) vector-expressed recombinant NAP in a concentration range of 4 ng/ml to 2000 ng/ml. MAb 23C8 antigen-binding depends on Tyr101 in a variable amino acid sequence of the NAP molecule, indicating the existence of antigenic variants among H. pylori strains. MAb 16F4 reacted with NAP from different H. pylori strains and was a sensitive tool for detection of small amounts of isolated NAP antigen or whole bacteria by immunoblotting or immunofluorescence. In conclusion, MAb-based immunoassays are highly specific and sensitive for detection of native NAP antigen and recombinant NAP immunostimulatory transgenes expressed by replication competent virus vectors.
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Affiliation(s)
- Ianko D Iankov
- Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55905, USA
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22
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Ping L, Platzer M, Wen G, Delaroque N. Coevolution of aah: a dps-like gene with the host bacterium revealed by comparative genomic analysis. ScientificWorldJournal 2012; 2012:504905. [PMID: 22454608 PMCID: PMC3289904 DOI: 10.1100/2012/504905] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Accepted: 11/14/2011] [Indexed: 11/17/2022] Open
Abstract
A protein named AAH was isolated from the bacterium Microbacterium arborescens SE14, a gut commensal of the lepidopteran larvae. It showed not only a high sequence similarity to Dps-like proteins (DNA-binding proteins from starved cell) but also reversible hydrolase activity. A comparative genomic analysis was performed to gain more insights into its evolution. The GC profile of the aah gene indicated that it was evolved from a low GC ancestor. Its stop codon usage was also different from the general pattern of Actinobacterial genomes. The phylogeny of dps-like proteins showed strong correlation with the phylogeny of host bacteria. A conserved genomic synteny was identified in some taxonomically related Actinobacteria, suggesting that the ancestor genes had incorporated into the genome before the divergence of Micrococcineae from other families. The aah gene had evolved new function but still retained the typical dodecameric structure.
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Affiliation(s)
- Liyan Ping
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, 07745 Jena, Germany
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23
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Iron trafficking system in Helicobacter pylori. Biometals 2011; 25:247-58. [PMID: 22127376 DOI: 10.1007/s10534-011-9512-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 11/16/2011] [Indexed: 12/14/2022]
Abstract
Helicobacter pylori infections are closely associated with peptic ulcers, gastric malignancy and iron deficiency anemia. Iron is essential for almost all living organisms and the investigation of iron uptake and trafficking system is thus important to understand the pathological roles of H. pylori. Up to now, the iron trafficking system of H. pylori is not yet fully clear and merits further efforts in this regards. The available information about iron uptake and regulation has been discussed in this concise review, such as FeoB in ferrous transportation, FrpB2 in hemoglobin uptake, HugZ in heme processing, virulence factors (VacA and CagA) in transferrin utilization, Pfr and NapA in iron storage and Fur in iron regulation. The identified iron trafficking system will help us to understand the pathological roles of H. pylori in the various gastric diseases and iron deficiency anemia and stimulates further development of effective anti-bacterial drugs.
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24
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Identification of Proteins Related to Nickel Homeostasis in Helicobater pylori by Immobilized Metal Affinity Chromatography and Two-Dimensional Gel Electrophoresis. Met Based Drugs 2011; 2008:289490. [PMID: 18288244 PMCID: PMC2225478 DOI: 10.1155/2008/289490] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2007] [Accepted: 10/21/2007] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori (H. pylori) is a widespread human pathogen causing peptic ulcers and chronic gastritis. Maintaining nickel homeostasis is crucial for the establishment of
H. pylori infection in humans. We used immobilized-nickel affinity chromatography to isolate Ni-related proteins from H. pylori cell extracts. Two-dimensional gel electrophoresis and mass spectrometry were employed to separate and identify twenty two Ni-interacting proteins in H. pylori. These Ni-interacting proteins can be classified into several general functional categories, including cellular processes (HspA, HspB, TsaA, and NapA), enzymes (Urease, Fumarase, GuaB, Cad, PPase, and DmpI), membrane-associated proteins (OM jhp1427 and HpaA), iron storage protein (Pfr), and hypothetical proteins (HP0271, HP jhp0216, HP jhp0301, HP0721, HP0614, and HP jhp0118). The implication of these proteins in nickel homeostasis is discussed.
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25
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Choli-Papadopoulou T, Kottakis F, Papadopoulos G, Pendas S. Helicobacter pylori neutrophil activating protein as target for new drugs against H. pylori inflammation. World J Gastroenterol 2011; 17:2585-91. [PMID: 21677824 PMCID: PMC3110918 DOI: 10.3748/wjg.v17.i21.2585] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 02/15/2011] [Accepted: 02/22/2011] [Indexed: 02/06/2023] Open
Abstract
Helicobacter pylori (H. pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer. Within this work we present the implication of C-terminal region of H. pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evidence that the C-terminal region of H. pylori activating protein is indispensable for neutrophil adhesion to endothelial cells, a step necessary to H. pylori inflammation. In addition we show that arabino galactan proteins derived from chios mastic gum, the natural resin of the plant Pistacia lentiscus var. Chia inhibit neutrophil activation in vitro.
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26
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Ideo H, Matsuzaka T, Nonaka T, Seko A, Yamashita K. Galectin-8-N-domain recognition mechanism for sialylated and sulfated glycans. J Biol Chem 2011; 286:11346-55. [PMID: 21288902 PMCID: PMC3064191 DOI: 10.1074/jbc.m110.195925] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 12/29/2010] [Indexed: 11/06/2022] Open
Abstract
Galectin-8 has much higher affinity for 3'-O-sulfated or 3'-O-sialylated glycoconjugates and a Lewis X-containing glycan than for oligosaccharides terminating in Galβ1→3/4GlcNAc, and this specificity is mainly attributed to the N-terminal carbohydrate recognition domain (N-domain, CRD) (Ideo, H., Seko, A., Ishizuka, I., and Yamashita, K. (2003) Glycobiology 13, 713-723). In this study, we elucidated the crystal structures of the human galectin-8-N-domain (-8N) in the absence or presence of 4 ligands. The apo molecule forms a dimer, which is different from the canonical 2-fold symmetric dimer observed for galectin-1 and -2. In a galectin-8N-lactose complex, the lactose-recognizing amino acids are highly conserved among the galectins. However, Arg(45), Gln(47), Arg(59), and the long loop region between the S3 and S4 β-strands are unique to galectin-8N. These amino acids directly or indirectly interact with the sulfate or sialic acid moieties of 3'-sialyl- and 3'-sulfolactose complexed with galectin-8N. Furthermore, in the LNF-III-galectin-8N complex, van der Waals interactions occur between the α1-3-branched fucose and galactose and between galactose and Tyr(141), and these interactions increase the affinity toward galectin-8N. Based on the findings of these x-ray crystallographic analyses, a mutagenesis study using surface plasmon resonance showed that Arg(45), Gln(47), and Arg(59) of galectin-8N are indispensable and coordinately contribute to the strong binding of galectins-8N to sialylated and sulfated oligosaccharides. Arg(59) is the most critical amino acid for binding in the S3-S4 loop region.
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Affiliation(s)
- Hiroko Ideo
- From the Innovative Research Initiatives, Tokyo Institute of Technology, Yokohama 226-8503 and
| | - Tsutomu Matsuzaka
- the School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan
| | - Takamasa Nonaka
- the School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan
| | - Akira Seko
- From the Innovative Research Initiatives, Tokyo Institute of Technology, Yokohama 226-8503 and
| | - Katsuko Yamashita
- From the Innovative Research Initiatives, Tokyo Institute of Technology, Yokohama 226-8503 and
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27
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Allison CC, Ferrero RL. Role of virulence factors and host cell signaling in the recognition of Helicobacter pylori and the generation of immune responses. Future Microbiol 2010; 5:1233-55. [PMID: 20722601 DOI: 10.2217/fmb.10.84] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Helicobacter pylori colonizes a large proportion of the world's population, with infection invariably leading to chronic, lifelong gastritis. While the infection often persists undiagnosed and without causing severe pathology, there are a number of host, bacterial and environmental factors that can influence whether infection provokes a mild inflammatory response or results in significant morbidity. Intriguingly, the most virulent H. pylori strains appear to deliberately induce the epithelial signaling cascades responsible for activating the innate immune system. While the reason for this remains unclear, the resulting adaptive immune responses are largely ineffective in clearing the bacterium once infection has become established and, as a result, inflammation likely causes more damage to the host itself.
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Affiliation(s)
- Cody C Allison
- Centre for Innate Immunity & Infectious Diseases, Monash Institute of Medical Research, Clayton, Australia.
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28
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Tissue Binding Patterns and In Vitro Effects of Campylobacter jejuni DNA-Binding Protein from Starved Cells. Neurochem Res 2010; 36:58-66. [DOI: 10.1007/s11064-010-0263-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2010] [Indexed: 11/26/2022]
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29
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Piao H, Minohara M, Kawamura N, Li W, Mizunoe Y, Umehara F, Goto Y, Kusunoki S, Matsushita T, Ikenaka K, Maejima T, Nabekura JI, Yamasaki R, Kira JI. Induction of paranodal myelin detachment and sodium channel loss in vivo by Campylobacter jejuni DNA-binding protein from starved cells (C-Dps) in myelinated nerve fibers. J Neurol Sci 2010; 288:54-62. [DOI: 10.1016/j.jns.2009.10.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 09/30/2009] [Accepted: 10/07/2009] [Indexed: 11/17/2022]
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30
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Li W, Minohara M, Piao H, Matsushita T, Masaki K, Matsuoka T, Isobe N, Su JJ, Ohyagi Y, Kira JI. Association of anti-Helicobacter pylori neutrophil-activating protein antibody response with anti-aquaporin-4 autoimmunity in Japanese patients with multiple sclerosis and neuromyelitis optica. Mult Scler 2009; 15:1411-21. [PMID: 19965522 DOI: 10.1177/1352458509348961] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
There are two distinct subtypes of multiple sclerosis (MS) in Asians: opticospinal (OSMS) and conventional (CMS). OSMS has similar features to neuromyelitis optica (NMO) and half of OSMS patients have the NMO-Immunoglobulin G (IgG)/ anti-aquaporin-4 (AQP4) antibody. We reported that Helicobacter pylori (H. pylori) infection was significantly less common in CMS patients than controls. To reveal the immune responses to the H. pylori neutrophil-activating protein (HP-NAP) in Japanese MS patients, according to anti-AQP4 antibody status, sera from 162 MS patients, 37 patients with other inflammatory neurological diseases (OIND), and 85 healthy subjects were assayed for anti-H. pylori antibodies, anti-HP-NAP antibodies, and myeloperoxidase (MPO) by enzyme immunoassays. H. pylori seropositivity rates were significantly higher in anti-AQP4 antibody-positive MS/NMO (AQP4 + /MS) patients (19/27, 70.4%) than anti-AQP4 antibody-negative CMS (AQP4 - /CMS) patients (22/83, 26.5%). Among H. pylori-infected individuals, the anti-HP-NAP antibody was significantly more common in AQP4 + /MS and AQP4 - /OSMS patients than healthy subjects (36.8%, 34.6% versus 2.8%). Among the AQP4 + /MS patients, a significant positive correlation between anti-HP-NAP antibody levels and the final Kurtzke's Expanded Disability Status Scale scores was found, and MPO levels were higher in anti-HP-NAP antibody-positive patients than anti-HP-NAP antibody-negative ones. Therefore, HP-NAP may be associated with the pathology of anti-AQP4 antibody-related neural damage in MS/NMO patients.
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Affiliation(s)
- Wei Li
- Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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31
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Ideo H, Fukushima K, Gengyo-Ando K, Mitani S, Dejima K, Nomura K, Yamashita K. A Caenorhabditis elegans glycolipid-binding galectin functions in host defense against bacterial infection. J Biol Chem 2009; 284:26493-501. [PMID: 19635802 DOI: 10.1074/jbc.m109.038257] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Galectins are a family of beta-galactoside-binding proteins that are widely found among animal species and that regulate diverse biological phenomena. To study the biological function of glycolipid-binding galectins, we purified recombinant Caenorhabditis elegans galectins (LEC-1-11) and studied their binding to C. elegans glycolipids. We found that LEC-8 binds to glycolipids in C. elegans through carbohydrate recognition. It has been reported that Cry5B-producing Bacillus thuringiensis strains can infect C. elegans and that the C. elegans Cry5B receptor molecules are glycolipids. We found that Cry5B and LEC-8 bound to C. elegans glycolipid-coated plates in a dose-dependent manner and that Cry5B binding to glycolipids was inhibited by the addition of LEC-8. LEC-8 is usually expressed strongly in the pharyngeal-intestinal valve and intestinal-rectal valve and is expressed weakly in intestine. However, when C. elegans were fed Escherichia coli expressing Cry5B, intestinal LEC-8::EGFP protein levels increased markedly. In contrast, LEC-8::EGFP expression triggered by Cry5B was reduced in toxin-resistant C. elegans mutants, which had mutations in genes involved in biosynthesis of glycolipids. Moreover, the LEC-8-deficient mutant was more susceptible to Cry5B than wild-type worms. These results suggest that the glycolipid-binding lectin LEC-8 contributes to host defense against bacterial infection by competitive binding to target glycolipid molecules.
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Affiliation(s)
- Hiroko Ideo
- Innovative Research Initiatives, Tokyo Institute of Technology, Yokohama 226-8503, USA
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Long M, Luo J, Li Y, Zeng FY, Li M. Detection and evaluation of antibodies against neutrophil-activating protein of Helicobacter pylori in patients with gastric cancer. World J Gastroenterol 2009; 15:2381-8. [PMID: 19452583 PMCID: PMC2684607 DOI: 10.3748/wjg.15.2381] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To detect and evaluate the antibodies against Helicobacter pylori (H pylori) neutrophil-activating protein (HP-NAP) in patients with gastric cancer and other gastroduodenal diseases.
METHODS: Recombinant HP-NAP was prepared from a prokaryotic expression system in Escherichia coli. Serum positivity and level of HP-NAP-specific antibodies in sera from 43 patients with gastric cancer, 28 with chronic gastritis, 28 with peptic ulcer, and 89 healthy controls were measured by rHP-NAP-based ELISA. rHP-NAP-stimulated production of interleukin-8 (IL-8) and growth-related oncogene (GROα) cytokines in the culture supernatant of SGC7901 gastric epithelial cells was also detected.
RESULTS: The serum positivity and mean absorbance value of HP-NAP-specific antibodies in the gastric cancer group (97.7% and 1.01 ± 0.24) were significantly higher than those in the chronic gastritis group (85.7% and 0.89 ± 0.14, P < 0.005) and healthy control group (27.7% and 0.65 ± 0.18, P < 0.001). The sensitivity and specificity of ELISA for the detection of HP-NAP-specific antibodies were 95.5% and 91.5%, respectively. HP-NAP could slightly up-regulate IL-8 production in gastric epithelial cell lines but had no effect on GROα production.
CONCLUSION: Infection with virulent H pylori strains secreting HP-NAP is associated with severe gastroduodenal diseases, and HP-NAP may play a role in the development of gastric carcinoma. rHP-NAP-based ELISA can be used as a new method to detect H pylori infection. The direct effect of HP-NAP on gastric epithelial cells may be limited, but HP-NAP may contribute to inflammatory response or carcinogenesis by activating neutrophils.
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Proença-Modena JL, Acrani GO, Brocchi M. Helicobacter pylori: phenotypes, genotypes and virulence genes. Future Microbiol 2009; 4:223-40. [PMID: 19257848 DOI: 10.2217/17460913.4.2.223] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Helicobacter pylori is a Gram-negative, microaerophilic bacterium that colonizes the gastric mucus overlying the epithelium of the stomach in more than 50% of the world's population. This gastric colonization induces chronic gastric inflammation in all infected individuals, but only induces clinical diseases in 10-20% of infected individuals. These include peptic ulcers, acute and atrophic gastritis, intestinal metaplasia, gastric adenocarcinoma and gastric B-cell lymphoma. Various bacterial virulence factors are associated with the development of such gastric diseases, and the characterization of these markers could aid medical prognosis, which could be extremely important in predicting clinical outcomes. The purpose of this review is to summarize the role of the phenotypes, virulence-related genes and genotypes of H. pylori in the establishment of gastric colonization and the development of associated diseases.
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Affiliation(s)
- José Luiz Proença-Modena
- Department of Cell & Molecular Biology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
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Jansson L, Tobias J, Jarefjäll C, Lebens M, Svennerholm AM, Teneberg S. Sulfatide recognition by colonization factor antigen CS6 from enterotoxigenic Escherichia coli. PLoS One 2009; 4:e4487. [PMID: 19242561 PMCID: PMC2647841 DOI: 10.1371/journal.pone.0004487] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 12/23/2008] [Indexed: 11/25/2022] Open
Abstract
The first step in the pathogenesis of enterotoxigenic Escherichia coli (ETEC) infections is adhesion of the bacterium to the small intestinal epithelium. Adhesion of ETEC is mediated by a number of antigenically distinct colonization factors, and among these, one of the most commonly detected is the non-fimbrial adhesin coli surface antigen 6 (CS6). The potential carbohydrate recognition by CS6 was investigated by binding of recombinant CS6-expressing E. coli and purified CS6 protein to a large number of variant glycosphingolipids separated on thin-layer chromatograms. Thereby, a highly specific binding of the CS6-expressing E. coli, and the purified CS6 protein, to sulfatide (SO3-3Galβ1Cer) was obtained. The binding of the CS6 protein and CS6-expressing bacteria to sulfatide was inhibited by dextran sulfate, but not by dextran, heparin, galactose 4-sulfate or galactose 6-sulfate. When using recombinantly expressed and purified CssA and CssB subunits of the CS6 complex, sulfatide binding was obtained with the CssB subunit, demonstrating that the glycosphingolipid binding capacity of CS6 resides within this subunit. CS6-binding sulfatide was present in the small intestine of species susceptible to CS6-mediated infection, e.g. humans and rabbits, but lacking in species not affected by CS6 ETEC, e.g. mice. The ability of CS6-expressing ETEC to adhere to sulfatide in target small intestinal epithelium may thus contribute to virulence.
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Affiliation(s)
- Lena Jansson
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Göteborg, Sweden
| | - Joshua Tobias
- Institute of Biomedicine, Department of Medical Microbiology and Immunology, University of Gothenburg, Göteborg, Sweden
| | - Catharina Jarefjäll
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Göteborg, Sweden
| | - Michael Lebens
- Institute of Biomedicine, Department of Medical Microbiology and Immunology, University of Gothenburg, Göteborg, Sweden
| | - Ann-Mari Svennerholm
- Institute of Biomedicine, Department of Medical Microbiology and Immunology, University of Gothenburg, Göteborg, Sweden
| | - Susann Teneberg
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Göteborg, Sweden
- * E-mail:
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Abstract
BACKGROUND The essential oil and Chios mastic gum (CMG) are natural antimicrobial agents currently broadly used in medicine owing to their antimicrobial, antioxidant, and hepatoprotective properties. The aim of this study was to investigate the effect of CMG-extracted arabinogalactan proteins (AGPs/CMG) both in vitro and in vivo, under the presence of Helicobacter pylori neutrophil-activating protein (HP-NAP), on the innate cellular immune effectors (neutrophils activations) comparing H. pylori-infected patients and healthy controls. PATIENTS AND METHODS The in-vivo effect of AGPs/CMG under the presence of HP-NAP in neutrophil activation was investigated in five H. pylori-infected patients and three healthy volunteers who received 1 g daily consumption of CMG for 2 months. All participants did not receive any immunosuppressive medication before or during the trial; patients with infectious diseases that could modify their immunologic status were excluded. In-vitro studies with pull-down experiments to assess the effect of AGPs/CMG under the presence of HP-NAP on the neutrophil activation were also carried out. Neutrophil activation was estimated by nicotinamide adenine dinucleotide phosphate-oxidase assays and optical microscopy methods by measurement of cytochrome C reduction. RESULTS Neutrophil activation was reduced when incubated in vitro with HP-NAP (P=0.0027) and AGP plus HP-NAP (P=0.0004) in H. pylori-positive patients who consumed AGP for 2 months. Similar results were also obtained when neutrophils were incubated with AGP plus HP-NAP (P=0.0038) in controls. Pull-down experiments showed a specific binding of AGPs to two membrane proteins of neutrophils, possibly suggesting inhibition of neutrophil activation. CONCLUSION AGPs/CMG inhibit neutrophil activation in the presence of HP-NAP, playing a crucial role in H. pylori-associated pathologies in gastric mucosa.
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Shoaf-Sweeney KD, Hutkins RW. Adherence, anti-adherence, and oligosaccharides preventing pathogens from sticking to the host. ADVANCES IN FOOD AND NUTRITION RESEARCH 2008; 55:101-61. [PMID: 18772103 DOI: 10.1016/s1043-4526(08)00402-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
For many pathogenic bacteria, infections are initiated only after the organism has first adhered to the host cell surface. If adherence can be inhibited, then the subsequent infection can also be inhibited. This approach forms the basis of anti-adherence strategies, which have been devised to prevent a variety of bacterial infections. In this chapter, the molecular basis by which respiratory, urinary, and gastrointestinal tract pathogens adhere to host cells will be described. The five general types of anti-adherence agents will also be reviewed. The most well-studied are the receptor analogs, which include oligosaccharides produced synthetically or derived from natural sources, including milk, berries, and other plants. Their ability to inhibit pathogen adherence may lead to development of novel, food-grade anti-infective agents that are inexpensive and safe.
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Affiliation(s)
- Kari D Shoaf-Sweeney
- School of Molecular Biosciences, Washington State University, Pullman, Washington 99164, USA
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37
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Linden SK, Sutton P, Karlsson NG, Korolik V, McGuckin MA. Mucins in the mucosal barrier to infection. Mucosal Immunol 2008; 1:183-97. [PMID: 19079178 PMCID: PMC7100821 DOI: 10.1038/mi.2008.5] [Citation(s) in RCA: 802] [Impact Index Per Article: 50.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The mucosal tissues of the gastrointestinal, respiratory, reproductive, and urinary tracts, and the surface of the eye present an enormous surface area to the exterior environment. All of these tissues are covered with resident microbial flora, which vary considerably in composition and complexity. Mucosal tissues represent the site of infection or route of access for the majority of viruses, bacteria, yeast, protozoa, and multicellular parasites that cause human disease. Mucin glycoproteins are secreted in large quantities by mucosal epithelia, and cell surface mucins are a prominent feature of the apical glycocalyx of all mucosal epithelia. In this review, we highlight the central role played by mucins in accommodating the resident commensal flora and limiting infectious disease, interplay between underlying innate and adaptive immunity and mucins, and the strategies used by successful mucosal pathogens to subvert or avoid the mucin barrier, with a particular focus on bacteria.
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Affiliation(s)
- S K Linden
- grid.1003.20000 0000 9320 7537Mucosal Diseases Program, Mater Medical Research Institute and The University of Queensland, Level 3 Aubigny Place, Mater Hospitals, South Brisbane, Queensland Australia
| | - P Sutton
- grid.1008.90000 0001 2179 088XCentre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Melbourne, Victoria Australia
| | - N G Karlsson
- grid.6142.10000 0004 0488 0789Department of Chemistry, Centre for BioAnalytical Sciences, National University of Ireland, Galway, Ireland
| | - V Korolik
- grid.1022.10000 0004 0437 5432Institute for Glycomics, Griffith University, Gold Coast, Queensland Australia
| | - M A McGuckin
- grid.1003.20000 0000 9320 7537Mucosal Diseases Program, Mater Medical Research Institute and The University of Queensland, Level 3 Aubigny Place, Mater Hospitals, South Brisbane, Queensland Australia
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38
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Teneberg S. The Multiple Carbohydrate Binding Specificities of Helicobacter pylori. Top Curr Chem (Cham) 2008; 288:121-38. [PMID: 22328028 DOI: 10.1007/128_2008_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Persistent colonization of the human stomach by Helicobacter pylori is a risk factor for the development of peptic ulcer disease and gastric cancer. Adhesion of microbes to the target tissue is an important determinant for successful initiation, establishment and maintenance of infection, and a variety of different candidate carbohydrate receptors for H. pylori have been identified. Here the different the binding specifities, and their potential role in adhesion to human gastric epithelium are described. Finally, recent findings on the roles of sialic acid binding SabA adhesin in interactions with human neutrophils and erythrocytes are discussed.
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Affiliation(s)
- Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Göteborg University, P.O. Box 440, 405 30 Göteborg, Sweden,
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Kottakis F, Papadopoulos G, Pappa EV, Cordopatis P, Pentas S, Choli-Papadopoulou T. Helicobacter pylori neutrophil-activating protein activates neutrophils by its C-terminal region even without dodecamer formation, which is a prerequisite for DNA protection--novel approaches against Helicobacter pylori inflammation. FEBS J 2007; 275:302-17. [PMID: 18076649 DOI: 10.1111/j.1742-4658.2007.06201.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Helicobacter pylori neutrophil-activating protein (HP-NAP) protects DNA from free radicals as a dodecamer through its ferroxidase activity without, however, directly binding to it. The retardation that was observed at pH 7.5 could be easily attributed to an iron effect, as it was revealed by experiments in the absence of HP-NAP. A total loss of ferroxidase activity, dodecamer formation and DNA protection in environments rich in free radicals was observed after replacement of His25, His37, Asp52 and Lys134, which are located within the ferroxidase site, with Ala. Molecular dynamics simulations revealed that dimer formation is highly unlikely following mutation of the above amino acids, as the Fe(2+) is no longer attracted with equal strength by both subunits. These findings probably indicate that iron plays an important role in the conformation of HP-NAP by initiating the formation of stable dimers that are indispensable for the ensuing dodecamer structure. Very surprisingly, neutrophil activation appeared to be stimulated by structural elements that are localized within the C-terminal region of both mutant HP-NAP and wild-type dodecamer HP-NAP. In particular, the dodecamer conformation does not seem to be necessary for activation, and helices H3 (Leu69-Leu75) and H4 (Lys89-Leu114) or the linking coils (His63-Thr68 and Thr76-Ser88) are probably critical in stimulating neutrophil activation.
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Affiliation(s)
- Filippos Kottakis
- Laboratory of Biochemistry, School of Chemistry, Aristotle University of Thessaloniki, TK 54124, Thessaloniki, Greece
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Huynh KK, Grinstein S. Regulation of vacuolar pH and its modulation by some microbial species. Microbiol Mol Biol Rev 2007; 71:452-62. [PMID: 17804666 PMCID: PMC2168644 DOI: 10.1128/mmbr.00003-07] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
To survive within the host, pathogens such as Mycobacterium tuberculosis and Helicobacter pylori need to evade the immune response and find a protected niche where they are not exposed to microbicidal effectors. The pH of the microenvironment surrounding the pathogen plays a critical role in dictating the organism's fate. Specifically, the acidic pH of the endocytic organelles and phagosomes not only can affect bacterial growth directly but also promotes a variety of host microbicidal responses. The development of mechanisms to avoid or resist the acidic environment generated by host cells is therefore crucial to the survival of many pathogens. Here we review the processes that underlie the generation of organellar acidification and discuss strategies employed by pathogens to circumvent it, using M. tuberculosis and H. pylori as examples.
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Affiliation(s)
- Kassidy K Huynh
- Cell Biology Program, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada M5G 1X8
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41
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Ping L, Büchler R, Mithöfer A, Svatos A, Spiteller D, Dettner K, Gmeiner S, Piel J, Schlott B, Boland W. A novel Dps-type protein from insect gut bacteria catalyses hydrolysis and synthesis of N-acyl amino acids. Environ Microbiol 2007; 9:1572-83. [PMID: 17504494 DOI: 10.1111/j.1462-2920.2007.01279.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A novel type of a microbial N-acyl amino acid hydrolase (AAH) from insect gut bacteria was purified, cloned and functionally characterized. The enzyme was obtained from Microbacterium arborescens SE14 isolated from the foregut of larvae of the generalist herbivore Spodoptera exigua. The substrates of AAH are N-acyl-glutamines previously reported to elicit plant defence reactions after introduction into the leaf during feeding. The isolated AAH catalyses the hydrolysis of the amide bond (K(m) = 36 micromol l(-1)) and, less efficient, the formation (K(m) = 3 mmol l(-1)) of the elicitor active N-acyl amino acids. The AAH from M. arborescens SE14 shows no homology to known fatty acyl amidases (EC 3.5.1.4) but belongs to the family of Dps proteins (DNA-binding protein from starved cell). In line with other DPS proteins AAH is a homododecamer (monomer 17 181 Da) and contains iron atoms (c. 1-16 iron atoms per subunit). Unlike genuine DPS proteins the enzyme does not significantly bind DNA. Amino acid hydrolase is the first member of the DPS family that catalyses the cleavage or formation of amide bonds. The participation of a microbial enzyme in the homeostasis of N-acyl-glutamines in the insect gut adds further complexity to the interaction between plants and their herbivores.
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Affiliation(s)
- Liyan Ping
- Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Str. 8, 07745 Jena, Germany
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D'Elios MM, Amedei A, Cappon A, Del Prete G, de Bernard M. The neutrophil-activating protein of Helicobacter pylori (HP-NAP) as an immune modulating agent. ACTA ACUST UNITED AC 2007; 50:157-64. [PMID: 17521355 DOI: 10.1111/j.1574-695x.2007.00258.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
During evolution microorganisms have developed several immune modulating strategies. The Helicobacter pylori neutrophil-activating protein (HP-NAP) is a virulence factor that attracts and activates neutrophils, and promotes their endothelial adhesion and the production of oxygen radicals and chemokines, including CXCL8, CCL3 and CCL4. HP-NAP, a TLR2 agonist, is an immune modulator able to induce the expression of interleukin-12 (IL-12) and IL-23 by human neutrophils and monocytes. In fact, HP-NAP has the potential to shift antigen-specific T-cell responses from a predominant Th2 to a polarized Th1 cytotoxic phenotype, characterized by high levels of interferon-gamma and tumor necrosis factor-alpha production. Thus, HP-NAP is a key factor driving Th1 inflammation in H. pylori infection and may be a new tool for future therapeutic strategies aimed at redirecting Th2 into Th1 responses, for example in atopy, vaccinology and cancer immunotherapy.
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43
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Polenghi A, Bossi F, Fischetti F, Durigutto P, Cabrelle A, Tamassia N, Cassatella MA, Montecucco C, Tedesco F, de Bernard M. The neutrophil-activating protein of Helicobacter pylori crosses endothelia to promote neutrophil adhesion in vivo. THE JOURNAL OF IMMUNOLOGY 2007; 178:1312-20. [PMID: 17237377 DOI: 10.4049/jimmunol.178.3.1312] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Helicobacter pylori induces an acute inflammatory response followed by a chronic infection of the human gastric mucosa characterized by infiltration of neutrophils/polymorphonuclear cells (PMNs) and mononuclear cells. The H. pylori neutrophil-activating protein (HP-NAP) activates PMNs, monocytes, and mast cells, and promotes PMN adherence to the endothelium in vitro. By using intravital microscopy analysis of rat mesenteric venules exposed to HP-NAP, we demonstrated, for the first time in vivo, that HP-NAP efficiently crosses the endothelium and promotes a rapid PMN adhesion. This HP-NAP-induced adhesion depends on the acquisition of a high affinity state of beta(2) integrin on the plasma membrane of PMNs, and this conformational change requires a functional p38 MAPK. We also show that HP-NAP stimulates human PMNs to synthesize and release a number of chemokines, including CXCL8, CCL3, and CCL4. Collectively, these data strongly support a central role for HP-NAP in the inflammation process in vivo: indeed, HP-NAP not only recruits leukocytes from the vascular lumen, but also stimulates them to produce messengers that may contribute to the maintenance of the flogosis associated with the H. pylori infection.
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Roche N, Ilver D, Angström J, Barone S, Telford JL, Teneberg S. Human gastric glycosphingolipids recognized by Helicobacter pylori vacuolating cytotoxin VacA. Microbes Infect 2007; 9:605-14. [PMID: 17400502 DOI: 10.1016/j.micinf.2007.01.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Revised: 01/03/2007] [Accepted: 01/24/2007] [Indexed: 12/01/2022]
Abstract
Many bacterial toxins utilize cell surface glycoconjugate receptors for attachment to target cells. In the present study the potential carbohydrate binding of Helicobacter pylori vacuolating cytotoxin VacA was investigated by binding to human gastric glycosphingolipids on thin-layer chromatograms. Thereby a distinct binding of the toxin to two compounds in the non-acid glycosphingolipid fraction was detected. The VacA-binding glycosphingolipids were isolated and characterized by mass spectrometry and proton NMR as galactosylceramide (Galbeta1Cer) and galabiosylceramide (Galalpha4Galbeta1Cer). Comparison of the binding preferences of the protein to reference glycosphingolipids from other sources showed an additional recognition of glucosylceramide (Glcbeta1Cer), lactosylceramide (Galbeta4Glcbeta1Cer) and globotriaosylceramide (Galalpha4Galbeta4Glcbeta1Cer). No binding to the glycosphingolipids recognized by the VacA holotoxin was obtained with a mutant toxin with deletion of the 37 kDa fragment of VacA (P58 molecule). Collectively our data show that the VacA cytotoxin is a glycosphingolipid binding protein, where the 37 kDa moiety is required for carbohydrate recognition. The ability to bind to short chain glycosphingolipids will position the toxin close to the cell membrane, which may facilitate toxin internalization.
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Affiliation(s)
- Niamh Roche
- Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Göteborg University, PO Box 440, S-405 30 Göteborg, Sweden
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45
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Aspholm M, Olfat FO, Nordén J, Sondén B, Lundberg C, Sjöström R, Altraja S, Odenbreit S, Haas R, Wadström T, Engstrand L, Semino-Mora C, Liu H, Dubois A, Teneberg S, Arnqvist A, Borén T. SabA is the H. pylori hemagglutinin and is polymorphic in binding to sialylated glycans. PLoS Pathog 2006; 2:e110. [PMID: 17121461 PMCID: PMC1626103 DOI: 10.1371/journal.ppat.0020110] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 09/07/2006] [Indexed: 12/13/2022] Open
Abstract
Adherence of Helicobacter pylori to inflamed gastric mucosa is dependent on the sialic acid–binding adhesin (SabA) and cognate sialylated/fucosylated glycans on the host cell surface. By in situ hybridization, H. pylori bacteria were observed in close association with erythrocytes in capillaries and post-capillary venules of the lamina propria of gastric mucosa in both infected humans and Rhesus monkeys. In vivo adherence of H. pylori to erythrocytes may require molecular mechanisms similar to the sialic acid–dependent in vitro agglutination of erythrocytes (i.e., sialic acid–dependent hemagglutination). In this context, the SabA adhesin was identified as the sialic acid–dependent hemagglutinin based on sialidase-sensitive hemagglutination, binding assays with sialylated glycoconjugates, and analysis of a series of isogenic sabA deletion mutants. The topographic presentation of binding sites for SabA on the erythrocyte membrane was mapped to gangliosides with extended core chains. However, receptor mapping revealed that the NeuAcα2–3Gal-disaccharide constitutes the minimal sialylated binding epitope required for SabA binding. Furthermore, clinical isolates demonstrated polymorphism in sialyl binding and complementation analysis of sabA mutants demonstrated that polymorphism in sialyl binding is an inherent property of the SabA protein itself. Gastric inflammation is associated with periodic changes in the composition of mucosal sialylation patterns. We suggest that dynamic adaptation in sialyl-binding properties during persistent infection specializes H. pylori both for individual variation in mucosal glycosylation and tropism for local areas of inflamed and/or dysplastic tissue. Helicobacter pylori infections are very common worldwide and cause chronic inflammation in the stomach (gastritis), which may progress to peptic ulcer disease and stomach cancer. In the gastric epithelium, H. pylori infections induce expression of inflammation-associated “sialylated” carbohydrates. The ability to bind to the glycosylated epithelial cells is considered to be essential for H. pylori to cause persistent infection and disease. Here the authors show that during established infection, H. pylori also binds to red blood cells in gastric mucosal blood vessels in both infected humans and Rhesus monkeys. The authors found that “sialic acid–binding adhesin” (SabA), is the bacterial surface protein that mediates binding of H. pylori to red blood cells. Furthermore, they show that clinical H. pylori isolates demonstrate “polymorphism” in their abilities to bind various sialylated carbohydrates, and that the variation in binding properties depends on the sialic acid–binding adhesin protein itself. This variability may adapt the binding properties of H. pylori both to individual hosts and the changing epithelial glycosylation patterns during chronic inflammation. Continuous adaptation to inflamed tissue during persistent infections is probably a general feature of microbial pathogens, although their binding properties have not yet been explored in detail.
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Affiliation(s)
- Marina Aspholm
- Department of Odontology, Section of Oral Microbiology, Umeå University, Umeå, Sweden
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Farzad O Olfat
- Department of Odontology, Section of Oral Microbiology, Umeå University, Umeå, Sweden
- The Swedish Institute for Infectious Disease Control, Solna, Sweden
| | - Jenny Nordén
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Berit Sondén
- Department of Odontology, Section of Oral Microbiology, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Carina Lundberg
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Rolf Sjöström
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Siiri Altraja
- Institute of Molecular and Cell Biology, Tartu University, Tartu, Estonia
| | - Stefan Odenbreit
- Max-von-Pettenkofer-Institute of Hygiene and Medical Microbiology, Department of Bacteriology, Munich, Germany
| | - Rainer Haas
- Max-von-Pettenkofer-Institute of Hygiene and Medical Microbiology, Department of Bacteriology, Munich, Germany
| | - Torkel Wadström
- Department of Infectious Diseases and Medical Microbiology, Lund University, Lund, Sweden
| | - Lars Engstrand
- The Swedish Institute for Infectious Disease Control, Solna, Sweden
| | - Cristina Semino-Mora
- Laboratory of Gastrointestinal and Liver Studies, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Hui Liu
- Laboratory of Gastrointestinal and Liver Studies, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - André Dubois
- Laboratory of Gastrointestinal and Liver Studies, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * To whom correspondence should be addressed. E-mail: (AD); (TB)
| | - Susann Teneberg
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, Göteborg University, Göteborg, Sweden
| | - Anna Arnqvist
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Thomas Borén
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
- * To whom correspondence should be addressed. E-mail: (AD); (TB)
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Sun B, Li ZS, Tu ZX, Xu GM, Du YQ. Construction of an oral recombinant DNA vaccine from H pylori neutrophil activating protein and its immunogenicity. World J Gastroenterol 2006; 12:7042-6. [PMID: 17109503 PMCID: PMC4087352 DOI: 10.3748/wjg.v12.i43.7042] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To construct a live attenuated Salmonella typhimurium (S. typhimurium) strain harboring the H pylori neutrophil activating protein (HP-NAP) gene as an oral recombinant DNA vaccine, and to evaluate its immunogenicity.
METHODS: By genetic engineering methods, the genomic DNA of H pylori was extracted as a template. The total length of the HP-NAP gene was amplified by polymerase chain reaction (PCR) and cloned into pBT vector for sequencing and BLAST analysis, then subcloned into a eukaryotic expression vector pIRES followed by PCR identification and restriction enzyme digestion. The identified recombinant plasmid pIRES-NAP was transfected into COS-7 cells for target fusion protein expression, and its antigenicity was detected by Western blotting. Then the recombinant plasmid was transformed into a live attenuated S. typhimurium strain SL7207 as an oral vaccine strain, and its immunogenicity was evaluated with animal experiments.
RESULTS: A 435 bp product was cloned using high homology with HP-NAP gene in GenBank (more than 98%). With identification by PCR and restriction enzyme digestion, a recombinant eukaryotic expression plasmid pIRES-NAP containing the HP-NAP gene of H pylori was successfully constructed. The expressed target protein had a specific reaction with H pylorii whole cell antibody and showed a single strip result detected by Western blotting. Oral immunization of mice with recombinant DNA vaccine strain SL7207 (pIRES-NAP) also induced a specific immune response.
CONCLUSION: The successful construction of HP-NAP oral DNA vaccine with good immunogenicity may help to further investigate its immunoprotection effects and develop vaccine against H pylori infection.
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Affiliation(s)
- Bo Sun
- Department of Gastroenterology, Changhai Hospital, Second Military Medical University, 174 Changhai Road, Shanghai 200433, China
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Wang G, Hong Y, Olczak A, Maier SE, Maier RJ. Dual Roles of Helicobacter pylori NapA in inducing and combating oxidative stress. Infect Immun 2006; 74:6839-46. [PMID: 17030577 PMCID: PMC1698064 DOI: 10.1128/iai.00991-06] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Neutrophil-activating protein (NapA) has been well documented to play roles in human neutrophil recruitment and in stimulating host cell production of reactive oxygen intermediates (ROI). A separate role for NapA in combating oxidative stress within H. pylori was implied by studies of various H. pylori mutant strains. Here, physiological analysis of a napA strain was the approach used to assess the iron-sequestering and stress resistance roles of NapA, its role in preventing oxidative DNA damage, and its importance to mouse colonization. The napA strain was more sensitive to oxidative stress reagents and to oxygen, and it contained fourfold more intracellular free iron and more damaged DNA than the parent strain. Pure, iron-loaded NapA bound to DNA, but native NapA did not, presumably linking iron levels sensed by NapA to DNA damage protection. Despite its in vitro phenotype of sensitivity to oxidative stress, the napA strain showed normal (like that of the wild type) mouse colonization efficiency in the conventional in vivo assay. By use of a modified mouse inoculation protocol whereby nonviable H. pylori is first inoculated into mice, followed by (live) bacterial strain administration, an in vivo role for NapA in colonization efficiency could be demonstrated. NapA is the critical component responsible for inducing host-mediated ROI production, thus inhibiting colonization by the napA strain. An animal colonization experiment with a mixed-strain infection protocol further demonstrated that the napA strain has significantly decreased ability to survive when competing with the wild type. H. pylori NapA has unique and separate roles in gastric pathogenesis.
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Affiliation(s)
- Ge Wang
- Department of Microbiology, 815 Biological Sciences Building, University of Georgia, Athens, GA 30602, USA
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48
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Abstract
The gastric pathogen Helicobacter pylori induces a strong inflammatory host response, yet the bacterium maintains long-term persistence in the host. H. pylori combats oxidative stress via a battery of diverse activities, some of which are unique or newly described. In addition to using the well-studied bacterial oxidative stress resistance enzymes superoxide dismutase and catalase, H. pylori depends on a family of peroxiredoxins (alkylhydroperoxide reductase, bacterioferritin co-migratory protein and a thiol-peroxidase) that function to detoxify organic peroxides. Newly described antioxidant proteins include a soluble NADPH quinone reductase (MdaB) and an iron sequestering protein (NapA) that has dual roles - host inflammation stimulation and minimizing reactive oxygen species production within H. pylori. An H. pylori arginase attenuates host inflammation, a thioredoxin required as a reductant for many oxidative stress enzymes is also a chaperon, and some novel properties of KatA and AhpC were discovered. To repair oxidative DNA damage, H. pylori uses an endonuclease (Nth), DNA recombination pathways and a newly described type of bacterial MutS2 that specifically recognizes 8-oxoguanine. A methionine sulphoxide reductase (Msr) plays a role in reducing the overall oxidized protein content of the cell, although it specifically targets oxidized Met residues. H. pylori possess few stress regulator proteins, but the key roles of a ferric uptake regulator (Fur) and a post-transcriptional regulator CsrA in antioxidant protein expression are described. The roles of all of these antioxidant systems have been addressed by a targeted mutant analysis approach and almost all are shown to be important in host colonization. The described antioxidant systems in H. pylori are expected to be relevant to many bacterial-associated diseases, as genes for most of the enzymes carrying out the newly described roles are present in a number of pathogenic bacteria.
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Affiliation(s)
- Ge Wang
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
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Petersson C, Forsberg M, Aspholm M, Olfat FO, Forslund T, Borén T, Magnusson KE. Helicobacter pylori SabA adhesin evokes a strong inflammatory response in human neutrophils which is down-regulated by the neutrophil-activating protein. Med Microbiol Immunol 2006; 195:195-206. [PMID: 16758245 DOI: 10.1007/s00430-006-0018-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Indexed: 12/14/2022]
Abstract
The human pathogen Helicobacter pylori expresses two dominant adhesins; the Lewis b blood group antigen binding adhesin, BabA, and the sialic acid-binding adhesin, SabA. These adhesins recognize specific carbohydrate moieties of the gastric epithelium, i.e. the Lewis b antigen, Le(b), and the sialyl-Lewis x antigen, sLe(x), respectively, which promote infection and inflammatory processes in the gastroduodenal tract. To assess the contribution of each of BabA, SabA and the neutrophil activating protein (HP-NAP) in a local inflammation, we investigated the traits of H. pylori mutants in their capacity to interact with and stimulate human neutrophils. We thence found that the SabA adhesin was not only the key inducer of oxidative metabolism (Unemo et al. J Biol Chem 280:15390-15397, 2005), but also essential in phagocytosis induction, as evaluated by flow cytometry, fluorescence microscopy and luminol-enhanced chemiluminescence. The napA deletion resulted in enhanced generation of reactive oxygen species and impaired adherence to the host cells. In conclusion, the SabA adhesin stimulates human neutrophils through selectin-mimicry. Interestingly, HP-NAP modulates the oxidative burst, which could tune the impact of the H. pylori infection for establishment of balanced and chronic inflammation of the gastric mucosa.
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Affiliation(s)
- Christoffer Petersson
- Division of Medical Microbiology, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden.
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Thumiger A, Polenghi A, Papinutto E, Battistutta R, Montecucco C, Zanotti G. Crystal structure of antigen TpF1 from Treponema pallidum. Proteins 2006; 62:827-30. [PMID: 16345079 DOI: 10.1002/prot.20828] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Anton Thumiger
- Dipartimento di Scienze Chimiche e ICB-CNR, Università di Padova, Padova, Italy
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