1
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Sijmons D, Collett S, Soliman C, Guy AJ, Scott AM, Durrant LG, Elbourne A, Walduck AK, Ramsland PA. Probing the expression and adhesion of glycans involved in Helicobacter pylori infection. Sci Rep 2024; 14:8587. [PMID: 38615147 PMCID: PMC11016089 DOI: 10.1038/s41598-024-59234-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 04/08/2024] [Indexed: 04/15/2024] Open
Abstract
Helicobacter pylori infects approximately half the human population and has an unusual infective niche of the human stomach. Helicobacter pylori is a major cause of gastritis and has been classified as a group 1 carcinogen by the WHO. Treatment involves triple or quadruple antibiotic therapy, but antibiotic resistance is becoming increasingly prevalent. Helicobacter pylori expresses certain blood group related antigens (Lewis system) as a part of its lipopolysaccharide (LPS), which is thought to assist in immune evasion. Additionally, H. pylori LPS participates in adhesion to host cells alongside several adhesion proteins. This study profiled the carbohydrates of H. pylori reference strains (SS1 and 26695) using monoclonal antibodies (mAbs) and lectins, identifying interactions between two carbohydrate-targeting mAbs and multiple lectins. Atomic force microscopy (AFM) scans were used to probe lectin and antibody interactions with the bacterial surfaces. The selected mAb and lectins displayed an increased adhesive force over the surface of the curved H. pylori rods. Furthermore, this study demonstrates the ability of anti-carbohydrate antibodies to reduce the adhesion of H. pylori 26695 to human gastric adenocarcinoma cells via AFM. Targeting bacterial carbohydrates to disrupt crucial adhesion and immune evasion mechanisms represents a promising strategy for combating H. pylori infection.
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Affiliation(s)
- Daniel Sijmons
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Simon Collett
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
- Department of Paediatrics, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Caroline Soliman
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, 3000, Australia
| | - Andrew J Guy
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
- ZiP Diagnostics, Collingwood, VIC, 3066, Australia
| | - Andrew M Scott
- Olivia Newton-John Cancer Research Institute and School of Cancer Medicine, La Trobe University, Melbourne, VIC, Australia
- Department of Molecular Imaging and Therapy, Austin Health and Faculty of Medicine, The University of Melbourne, Melbourne, VIC, Australia
| | - Lindy G Durrant
- Scancell Limited, University of Nottingham Biodiscovery Institute, Nottingham, UK
- Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, Nottingham, UK
| | - Aaron Elbourne
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia
| | - Anna K Walduck
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia.
- Rural Health Research Institute, Charles Sturt University, Orange, NSW, 2800, Australia.
| | - Paul A Ramsland
- School of Science, RMIT University, Melbourne, VIC, 3000, Australia.
- Department of Immunology, Monash University, Melbourne, VIC, 3004, Australia.
- Department of Surgery, Austin Health, The University of Melbourne, Heidelberg, VIC, 3084, Australia.
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2
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Dyankov G, Eftimov T, Hikova E, Najdenski H, Kussovski V, Genova-Kalou P, Mankov V, Kisov H, Veselinov P, Ghaffari SS, Kovacheva-Slavova M, Vladimirov B, Malinowski N. SPR and Double Resonance LPG Biosensors for Helicobacter pylori BabA Antigen Detection. SENSORS (BASEL, SWITZERLAND) 2024; 24:2118. [PMID: 38610328 PMCID: PMC11014364 DOI: 10.3390/s24072118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Revised: 03/14/2024] [Accepted: 03/24/2024] [Indexed: 04/14/2024]
Abstract
Given the medical and social significance of Helicobacter pylori infection, timely and reliable diagnosis of the disease is required. The traditional invasive and non-invasive conventional diagnostic techniques have several limitations. Recently, opportunities for new diagnostic methods have appeared based on the recent advance in the study of H. pylori outer membrane proteins and their identified receptors. In the present study we assess the way in which outer membrane protein-cell receptor reactions are applicable in establishing a reliable diagnosis. Herein, as well as in other previous studies of ours, we explore the reliability of the binding reaction between the best characterized H. pylori adhesin BabA and its receptor, the blood antigen Leb. For the purpose we developed surface plasmon resonance (SPR) and double resonance long period grating (DR LPG) biosensors based on the BabA-Leb binding reaction for diagnosing H. pylori infection. In SPR detection, the sensitivity was estimated at 3000 CFU/mL-a much higher sensitivity than that of the RUT test. The DR LPG biosensor proved to be superior in terms of accuracy and sensitivity-concentrations as low as 102 CFU/mL were detected.
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Affiliation(s)
- Georgi Dyankov
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
- Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 61 Sankt Petersburg Blvd., 4000 Plovdiv, Bulgaria;
| | - Tinko Eftimov
- Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 61 Sankt Petersburg Blvd., 4000 Plovdiv, Bulgaria;
- Photonics Research Center, Université du Québec en Outaouais, Rue 101 St-Jean Bosco, Gatineau, QC J8X 3G5, Canada;
| | - Evdokiya Hikova
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
| | - Hristo Najdenski
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 26 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; (H.N.); (V.K.)
| | - Vesselin Kussovski
- The Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 26 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; (H.N.); (V.K.)
| | - Petia Genova-Kalou
- National Center of Infectious and Parasitic Diseases, 44A “Gen. Stoletov” Blvd., 1233 Sofia, Bulgaria;
| | - Vihar Mankov
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
| | - Hristo Kisov
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
- Central Laboratory of Applied Physics, Bulgarian Academy of Sciences, 61 Sankt Petersburg Blvd., 4000 Plovdiv, Bulgaria;
| | - Petar Veselinov
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
| | - Sanaz Shoar Ghaffari
- Photonics Research Center, Université du Québec en Outaouais, Rue 101 St-Jean Bosco, Gatineau, QC J8X 3G5, Canada;
- Department of Electrical and Computer Engineering, University of Alberta, 116 St & 85 Ave, Edmonton, AB T6G 2R3, Canada
| | - Mila Kovacheva-Slavova
- Department of Gastroenterology, University Hospital Tsaritsa Ioanna-ISUL, Medical University Sofia, 8 “Byalo More” Str., 1527 Sofia, Bulgaria; (M.K.-S.); (B.V.)
| | - Borislav Vladimirov
- Department of Gastroenterology, University Hospital Tsaritsa Ioanna-ISUL, Medical University Sofia, 8 “Byalo More” Str., 1527 Sofia, Bulgaria; (M.K.-S.); (B.V.)
| | - Nikola Malinowski
- Institute of Optical Materials and Technologies “Acad. J. Malinowski” (IOMT), Bulgarian Academy of Sciences (BAS), 109 “Acad. G. Bonchev” Str., 1113 Sofia, Bulgaria; (G.D.); (V.M.); (H.K.); (P.V.); (N.M.)
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3
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Sijmons D, Guy AJ, Walduck AK, Ramsland PA. Helicobacter pylori and the Role of Lipopolysaccharide Variation in Innate Immune Evasion. Front Immunol 2022; 13:868225. [PMID: 35634347 PMCID: PMC9136243 DOI: 10.3389/fimmu.2022.868225] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/04/2022] [Indexed: 11/30/2022] Open
Abstract
Helicobacter pylori is an important human pathogen that infects half the human population and can lead to significant clinical outcomes such as acute and chronic gastritis, duodenal ulcer, and gastric adenocarcinoma. To establish infection, H. pylori employs several mechanisms to overcome the innate and adaptive immune systems. H. pylori can modulate interleukin (IL) secretion and innate immune cell function by the action of several virulence factors such as VacA, CagA and the type IV secretion system. Additionally, H. pylori can modulate local dendritic cells (DC) negatively impacting the function of these cells, reducing the secretion of immune signaling molecules, and influencing the differentiation of CD4+ T helper cells causing a bias to Th1 type cells. Furthermore, the lipopolysaccharide (LPS) of H. pylori displays a high degree of phase variation and contains human blood group carbohydrate determinants such as the Lewis system antigens, which are proposed to be involved in molecular mimicry of the host. Lastly, the H. pylori group of outer membrane proteins such as BabA play an important role in attachment and interaction with host Lewis and other carbohydrate antigens. This review examines the various mechanisms that H. pylori utilises to evade the innate immune system as well as discussing how the structure of the H. pylori LPS plays a role in immune evasion.
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Affiliation(s)
- Daniel Sijmons
- School of Science, RMIT University, Melbourne, VIC, Australia
| | - Andrew J. Guy
- School of Science, RMIT University, Melbourne, VIC, Australia
- ZiP Diagnostics, Collingwood, VIC, Australia
| | - Anna K. Walduck
- School of Science, RMIT University, Melbourne, VIC, Australia
| | - Paul A. Ramsland
- School of Science, RMIT University, Melbourne, VIC, Australia
- Department of Immunology, Monash University, Melbourne, VIC, Australia
- Department of Surgery, Austin Health, University of Melbourne, Heidelberg, VIC, Australia
- *Correspondence: Paul A. Ramsland,
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4
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Silva LM, Correia VG, Moreira ASP, Domingues MRM, Ferreira RM, Figueiredo C, Azevedo NF, Marcos-Pinto R, Carneiro F, Magalhães A, Reis CA, Feizi T, Ferreira JA, Coimbra MA, Palma AS. Helicobacter pylori lipopolysaccharide structural domains and their recognition by immune proteins revealed with carbohydrate microarrays. Carbohydr Polym 2020; 253:117350. [PMID: 33278960 DOI: 10.1016/j.carbpol.2020.117350] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/16/2020] [Accepted: 10/29/2020] [Indexed: 01/04/2023]
Abstract
The structural diversity of the lipopolysaccharides (LPSs) from Helicobacter pylori poses a challenge to establish accurate and strain-specific structure-function relationships in interactions with the host. Here, LPS structural domains from five clinical isolates were obtained and compared with the reference strain 26695. This was achieved combining information from structural analysis (GC-MS and ESI-MSn) with binding data after interrogation of a LPS-derived carbohydrate microarray with sequence-specific proteins. All LPSs expressed Lewisx/y and N-acetyllactosamine determinants. Ribans were also detected in LPSs from all clinical isolates, allowing their distinction from the 26695 LPS. There was evidence for 1,3-d-galactans and blood group H-type 2 sequences in two of the clinical isolates, the latter not yet described for H. pylori LPS. Furthermore, carbohydrate microarray analyses showed a strain-associated LPS recognition by the immune lectins DC-SIGN and galectin-3 and revealed distinctive LPS binding patterns by IgG antibodies in the serum from H. pylori-infected patients.
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Affiliation(s)
- Lisete M Silva
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; Glycosciences Laboratory, Department of Metabolism, Digestion and Reproduction, Imperial College London, W12 0NN, UK.
| | - Viviana G Correia
- UCIBIO, Department of Chemistry, School of Science and Technology, NOVA University of Lisbon, 2829-516 Lisbon, Portugal
| | - Ana S P Moreira
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Maria Rosário M Domingues
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal; CESAM - Centre for Environmental and Marine Studies, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Rui M Ferreira
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal
| | - Céu Figueiredo
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal; Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Nuno F Azevedo
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - Ricardo Marcos-Pinto
- ICBAS - Institute of Biomedical Sciences Abel Salazar, University of Porto, 4050-313 Porto, Portugal; Department of Gastroenterology, Centro Hospitalar do Porto, 4099-001 Porto, Portugal; Medical Faculty, Centre for Research in Health Technologies and Information Systems, 4200-450 Porto, Portugal
| | - Fátima Carneiro
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; Department of Pathology, Centro Hospitalar Universitário de São João (CHUSJ), 4200-319 Porto, Portugal
| | - Ana Magalhães
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal
| | - Celso A Reis
- i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal; IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465 Porto, Portugal; Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal; ICBAS - Institute of Biomedical Sciences Abel Salazar, University of Porto, 4050-313 Porto, Portugal
| | - Ten Feizi
- Glycosciences Laboratory, Department of Metabolism, Digestion and Reproduction, Imperial College London, W12 0NN, UK
| | - José A Ferreira
- ICBAS - Institute of Biomedical Sciences Abel Salazar, University of Porto, 4050-313 Porto, Portugal; Experimental Pathology and Therapeutics Group, Research Center (CI-IPOP), Portuguese Institute of Oncology, 4200-072 Porto, Portugal
| | - Manuel A Coimbra
- LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Angelina S Palma
- Glycosciences Laboratory, Department of Metabolism, Digestion and Reproduction, Imperial College London, W12 0NN, UK; UCIBIO, Department of Chemistry, School of Science and Technology, NOVA University of Lisbon, 2829-516 Lisbon, Portugal
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5
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Negrini R, Villanacci V, Poiesi C, Savio A. Anti-Glycan Autoantibodies Induced by Helicobacter pylori as a Potential Risk Factor for Myocardial Infarction. Front Immunol 2020; 11:597. [PMID: 32322255 PMCID: PMC7158853 DOI: 10.3389/fimmu.2020.00597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 03/16/2020] [Indexed: 12/15/2022] Open
Abstract
A number of epidemiological studies have evaluated the potential association between H. pylori and cardiovascular disease, but with contrasting results. We have previously shown that Helicobacter pylori infection is able to induce in mice and humans autoantibodies cross-reacting with histo–blood group Lewis antigens, expressed in different organs and in plasma glycoproteins and glycolipids. The aim of this study was to assess whether immunization of animals with H. pylori might induce myocardial histopathological changes. We have retrospectively examined, in detail, the histology of archived organs from mice and rabbits immunized with H. pylori in our previous studies. Human sera and cross-reacting monoclonal antibodies were also tested against bacterial preparations and tissue sections. Areas of myocardial necrosis, associated with coronary thrombotic occlusion, were found in 5 of 20 mice and 2 of 5 rabbits previously immunized with suspensions of H. pylori. No similar lesions were found in control animals, suggesting a causal link with H. pylori immunization. The animals bearing myocardial lesions had not been infected but only immunized months earlier with parenteral injections of dead H. pylori cells. This strongly suggests that immunization, by itself, might play a causative role. We propose that the cross-reactive autoimmune response induced by H. pylori could promote thrombotic occlusion through direct endothelial damage or by perturbing the coagulation process.
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Affiliation(s)
- Riccardo Negrini
- Department of Laboratory Medicine, Presidio di Gardone VT-ASST Spedali Civili, Brescia, Italy
| | | | - Claudio Poiesi
- Institute of Microbiology and Virology, ASST Spedali Civili, Brescia, Italy
| | - Antonella Savio
- Histopathology and Cytology Department, The Royal Marsden NHS Foundation Trust, London, United Kingdom
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6
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Gottesmann M, Paraskevopoulou V, Mohammed A, Falcone FH, Hensel A. BabA and LPS inhibitors against Helicobacter pylori: pectins and pectin-like rhamnogalacturonans as adhesion blockers. Appl Microbiol Biotechnol 2019; 104:351-363. [PMID: 31768613 DOI: 10.1007/s00253-019-10234-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 10/15/2019] [Accepted: 10/31/2019] [Indexed: 12/17/2022]
Abstract
The first step in the development of Helicobacter pylori pathogenicity is receptor-mediated adhesion to gastric epithelium. Adhesins of H. pylori not only enable colonisation of the epithelium, with BabA interacting with Lewisb, but also interaction of lipopolysaccharide (LPS) with galectin-3 contributes to attachment of H. pylori to the host cells. Anti-adhesive compounds against H. pylori have been described, but specific analytical assays for pinpointing the interaction with BabA are limited. LPS-galectin-3 inhibitors have not been described until now. A sandwich ELISA with recombinant BabA547-6K was developed to investigate the interaction of BabA with Lewisb-HSA. Isothermal titration calorimetry gave thermodynamic information on the interaction between BabA, Lewisb-HSA and anti-adhesive compounds. A highly esterified rhamnogalacturonan from Abelmoschus esculentus inhibited the adhesion of H. pylori to adherent gastric adenocarcinoma (AGS) cells (IC50 550 μg/mL) and interacted with BabA (IC50 17 μg/mL). Pectins with similar rhamnogalacturonan structure showed weak anti-adhesive activity. Highly branched rhamnogalacturonans with low uronic acid content and high degree of esterification are potent BabA inhibitors. BabA represents a promising target for the development of anti-adhesive drugs against H. pylori. The rhamnogalacturonan influenced also the binding affinity of H. pylori to recombinant galectin-3 in a concentration-dependent manner with an IC50 of 222 μg/mL. Similar effects were obtained with pectin from apple fruits, while pectins from other sources were inactive.
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Affiliation(s)
- Maren Gottesmann
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, Corrensstrasse 48, 48149, Münster, Germany
| | | | - Aymen Mohammed
- Institute for Parasitology, University of Giessen, Schubertstrasse 81, 35392, Giessen, Germany
| | - Franco H Falcone
- Institute for Parasitology, University of Giessen, Schubertstrasse 81, 35392, Giessen, Germany
| | - Andreas Hensel
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, Corrensstrasse 48, 48149, Münster, Germany.
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7
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Alfarouk KO, Bashir AHH, Aljarbou AN, Ramadan AM, Muddathir AK, AlHoufie STS, Hifny A, Elhassan GO, Ibrahim ME, Alqahtani SS, AlSharari SD, Supuran CT, Rauch C, Cardone RA, Reshkin SJ, Fais S, Harguindey S. The Possible Role of Helicobacter pylori in Gastric Cancer and Its Management. Front Oncol 2019; 9:75. [PMID: 30854333 PMCID: PMC6395443 DOI: 10.3389/fonc.2019.00075] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/28/2019] [Indexed: 12/17/2022] Open
Abstract
Helicobacter pylori (HP) is a facultative anaerobic bacterium. HP is a normal flora having immuno-modulating properties. This bacterium is an example of a microorganism inducing gastric cancer. Its carcinogenicity depends on bacteria-host related factors. The proper understanding of the biology of HP inducing gastric cancer offers the potential strategy in the managing of HP rather than eradicating it. In this article, we try to summarize the biology of HP-induced gastric cancer and discuss the current pharmacological approach to treat and prevent its carcinogenicity.
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Affiliation(s)
- Khalid O Alfarouk
- Alfarouk Biomedical Research LLC, Tampa, FL, United States.,Hala Alfarouk Cancer Center, Khartoum, Sudan.,Al-Ghad International College for Applied Medical Sciences, Medina, Saudi Arabia.,American Biosciences, Inc., New York City, NY, United States
| | - Adil H H Bashir
- Hala Alfarouk Cancer Center, Khartoum, Sudan.,Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Ahmed N Aljarbou
- College of Pharmacy, Qassim University, Buraydah, Saudi Arabia.,Al-Ghad International College for Applied Medical Sciences, Jeddah, Saudi Arabia
| | | | - Abdel Khalig Muddathir
- Hala Alfarouk Cancer Center, Khartoum, Sudan.,Department of Pharmacognosy, Faculty of Pharmacy, University of Khartoum, Khartoum, Sudan
| | - Sari T S AlHoufie
- Al-Ghad International College for Applied Medical Sciences, Medina, Saudi Arabia.,Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Taibah University, Medina, Saudi Arabia
| | | | - Gamal O Elhassan
- Unaizah College of Pharmacy, Qassim University, Unaizah, Saudi Arabia
| | | | - Saad S Alqahtani
- Clinical Pharmacy Department, College of pharmacy, Jazan University, Jazan, Saudi Arabia
| | - Shakir D AlSharari
- Department of Pharmacology and Toxicology, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.,Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA, United States
| | | | - Cyril Rauch
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, United Kingdom
| | - Rosa Angela Cardone
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Stephan J Reshkin
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Stefano Fais
- Department of Oncology and Molecular Medicine, National Institute of Health, Rome, Italy
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8
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Li H, Tang H, Debowski AW, Stubbs KA, Marshall BJ, Benghezal M. Lipopolysaccharide Structural Differences between Western and Asian Helicobacter pylori Strains. Toxins (Basel) 2018; 10:toxins10090364. [PMID: 30205541 PMCID: PMC6162551 DOI: 10.3390/toxins10090364] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 07/30/2018] [Accepted: 08/09/2018] [Indexed: 02/05/2023] Open
Abstract
Recent structural analysis of the lipopolysaccharide (LPS) isolated from Helicobacter pylori G27 wild-type and O-antigen ligase mutant resulted in the redefinition of the core-oligosaccharide and O-antigen domains. The short core-oligosaccharide (Glc–Gal–Hep-III–Hep-II–Hep-I–KDO) and its attached trisaccharide (Trio, GlcNAc–Fuc–Hep) appear to be highly conserved structures among H. pylori strains. The G27 LPS contains a linear glucan–heptan linker between the core-Trio and distal Lewis antigens. This linker domain was commonly identified in Western strains. In contrast, out of 12 partial LPS structures of Asian strains, none displayed the heptan moiety, despite the presence of Lewis antigens. This raises the question of how Lewis antigens are attached to the Trio, and whether the LPS structure of Asian strains contain another linker. Of note, a riban was identified as a linker in LPS of the mouse-adapted SS1 strain, suggesting that alternative linker structures can occur. In summary, additional full structural analyses of LPS in Asian strains are required to assess the presence or absence of an alternative linker in these strains. It will also be interesting to study the glucan-heptan linker moieties in pathogenesis as H. pylori infections in Asia are usually more symptomatic than the ones presented in the Western world.
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Affiliation(s)
- Hong Li
- West China Marshall Research Center for Infectious Diseases, Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu 610041, China.
| | - Hong Tang
- West China Marshall Research Center for Infectious Diseases, Center of Infectious Diseases, West China Hospital of Sichuan University, Chengdu 610041, China.
| | - Aleksandra W Debowski
- Helicobacter pylori Research Laboratory, School of Biomedical Sciences, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands, WA 6009, Australia.
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia.
| | - Keith A Stubbs
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia.
| | - Barry J Marshall
- Helicobacter pylori Research Laboratory, School of Biomedical Sciences, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands, WA 6009, Australia.
| | - Mohammed Benghezal
- Helicobacter pylori Research Laboratory, School of Biomedical Sciences, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands, WA 6009, Australia.
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9
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Leker K, Lozano-Pope I, Bandyopadhyay K, Choudhury BP, Obonyo M. Comparison of lipopolysaccharides composition of two different strains of Helicobacter pylori. BMC Microbiol 2017; 17:226. [PMID: 29202699 PMCID: PMC5715995 DOI: 10.1186/s12866-017-1135-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Accepted: 11/23/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Helicobacter pylori (H. pylori) is a Gram-negative, microaerophilic bacterium that is recognized as a major cause of chronic gastritis, peptic ulcers, and gastric cancer. Comparable to other Gram-negative bacteria, lipopolysaccharides (LPS) are an important cellular component of the outer membrane of H. pylori. The LPS of this organism plays a key role in its colonization and persistence in the stomach. In addition, H. pylori LPS modulates pathogen-induced host inflammatory responses resulting in chronic inflammation within the gastrointestinal tract. Very little is known about the comparative LPS compositions of different strains of H. pylori with varied degree of virulence in human. Therefore, LPS was analyzed from two strains of H. pylori with differing potency in inducing inflammatory responses (SS1 and G27). LPS were extracted from aqueous and phenol layer of hot-phenol water extraction method and subjected for composition analysis by gas chromatography - mass spectrometry (GC-MS) to sugar and fatty acid compositions. RESULTS The major difference between the two strains of H. pylori is the presence of Rhamnose, Fucose and GalNAc in the SS1 strain, which was either not found or with low abundance in the G27 strain. On the other hand, high amount of Mannose was present in G27 in comparison to SS1. Fatty acid composition of lipid-A portion also showed considerable amount of differences between the two strains, phenol layer of SS1 had enhanced amount of 3 hydroxy decanoic acid (3-OH-C10:0) and 3-hydroxy dodecanoic acid (3-OH-C12:0) which were not present in G27, whereas myristic acid (C14:0) was present in G27 in relatively high amount. CONCLUSION The composition analysis of H. pylori LPS, revealed differences in sugars and fatty acids composition between a mouse adapted strain SS1 and G27. This knowledge provides a novel way to dissect out their importance in host-pathogen interaction in further studies.
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Affiliation(s)
- Kristy Leker
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, California 92093 USA
| | - Ivonne Lozano-Pope
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, California 92093 USA
| | - Keya Bandyopadhyay
- Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, California 92093 USA
| | - Biswa P. Choudhury
- Glycotechnology Core Resources, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, California 92093 USA
| | - Marygorret Obonyo
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, California 92093 USA
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10
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Helicobacter pylori modulates host cell responses by CagT4SS-dependent translocation of an intermediate metabolite of LPS inner core heptose biosynthesis. PLoS Pathog 2017; 13:e1006514. [PMID: 28715499 PMCID: PMC5531669 DOI: 10.1371/journal.ppat.1006514] [Citation(s) in RCA: 90] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 07/27/2017] [Accepted: 07/05/2017] [Indexed: 12/15/2022] Open
Abstract
Highly virulent Helicobacter pylori cause proinflammatory signaling inducing the transcriptional activation and secretion of cytokines such as IL-8 in epithelial cells. Responsible in part for this signaling is the cag pathogenicity island (cagPAI) that codetermines the risk for pathological sequelae of an H. pylori infection such as gastric cancer. The Cag type IV secretion system (CagT4SS), encoded on the cagPAI, can translocate various molecules into cells, the effector protein CagA, peptidoglycan metabolites and DNA. Although these transported molecules are known to contribute to cellular responses to some extent, a major part of the cagPAI-induced signaling leading to IL-8 secretion remains unexplained. We report here that biosynthesis of heptose-1,7-bisphosphate (HBP), an important intermediate metabolite of LPS inner heptose core, contributes in a major way to the H. pylori cagPAI-dependent induction of proinflammatory signaling and IL-8 secretion in human epithelial cells. Mutants defective in the genes required for synthesis of HBP exhibited a more than 95% reduction of IL-8 induction and impaired CagT4SS-dependent cellular signaling. The loss of HBP biosynthesis did not abolish the ability to translocate CagA. The human cellular adaptor TIFA, which was described before to mediate HBP-dependent activity in other Gram-negative bacteria, was crucial in the cagPAI- and HBP pathway-induced responses by H. pylori in different cell types. The active metabolite was present in H. pylori lysates but not enriched in bacterial supernatants. These novel results advance our mechanistic understanding of H. pylori cagPAI-dependent signaling mediated by intracellular pattern recognition receptors. They will also allow to better dissect immunomodulatory activities by H. pylori and to improve the possibilities of intervention in cagPAI- and inflammation-driven cancerogenesis. The Cag Type IV secretion system, which contributes to inflammation and cancerogenesis during chronic infection, is one of the major virulence and fitness factors of the bacterial gastric pathogen Helicobacter pylori. Up to now, the mechanisms leading to cagPAI-dependent signal transduction and cytokine secretion were not completely understood. We report here that HBP, an intermediate metabolite in LPS core heptose biosynthesis, is translocated into host cells dependent on the CagT4SS, and is a major factor leading to the activation of cellular responses. This response is connected to the human cellular adaptor protein TIFA. The knowledge of this specific response pathway is a major advance in understanding CagT4SS-dependent signaling and will enable us to understand better how H. pylori modulates the immune response repertoire in its human host.
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11
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The redefinition of Helicobacter pylori lipopolysaccharide O-antigen and core-oligosaccharide domains. PLoS Pathog 2017; 13:e1006280. [PMID: 28306723 PMCID: PMC5371381 DOI: 10.1371/journal.ppat.1006280] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/29/2017] [Accepted: 03/08/2017] [Indexed: 02/05/2023] Open
Abstract
Helicobacter pylori lipopolysaccharide promotes chronic gastric colonisation through O-antigen host mimicry and resistance to mucosal antimicrobial peptides mediated primarily by modifications of the lipid A. The structural organisation of the core and O-antigen domains of H. pylori lipopolysaccharide remains unclear, as the O-antigen attachment site has still to be identified experimentally. Here, structural investigations of lipopolysaccharides purified from two wild-type strains and the O-antigen ligase mutant revealed that the H. pylori core-oligosaccharide domain is a short conserved hexasaccharide (Glc-Gal-DD-Hep-LD-Hep-LD-Hep-KDO) decorated with the O-antigen domain encompassing a conserved trisaccharide (-DD-Hep-Fuc-GlcNAc-) and variable glucan, heptan and Lewis antigens. Furthermore, the putative heptosyltransferase HP1284 was found to be required for the transfer of the third heptose residue to the core-oligosaccharide. Interestingly, mutation of HP1284 did not affect the ligation of the O-antigen and resulted in the attachment of the O-antigen onto an incomplete core-oligosaccharide missing the third heptose and the adjoining Glc-Gal residues. Mutants deficient in either HP1284 or O-antigen ligase displayed a moderate increase in susceptibility to polymyxin B but were unable to colonise the mouse gastric mucosa. Finally, mapping mutagenesis and colonisation data of previous studies onto the redefined organisation of H. pylori lipopolysaccharide revealed that only the conserved motifs were essential for colonisation. In conclusion, H. pylori lipopolysaccharide is missing the canonical inner and outer core organisation. Instead it displays a short core and a longer O-antigen encompassing residues previously assigned as the outer core domain. The redefinition of H. pylori lipopolysaccharide domains warrants future studies to dissect the role of each domain in host-pathogen interactions. Also enzymes involved in the assembly of the conserved core structure, such as HP1284, could be attractive targets for the design of new therapeutic agents for managing persistent H. pylori infection causing peptic ulcers and gastric cancer.
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12
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Li H, Liao T, Debowski AW, Tang H, Nilsson HO, Stubbs KA, Marshall BJ, Benghezal M. Lipopolysaccharide Structure and Biosynthesis in Helicobacter pylori. Helicobacter 2016; 21:445-461. [PMID: 26934862 DOI: 10.1111/hel.12301] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This review covers the current knowledge and gaps in Helicobacter pylori lipopolysaccharide (LPS) structure and biosynthesis. H. pylori is a Gram-negative bacterium which colonizes the luminal surface of the human gastric epithelium. Both a constitutive alteration of the lipid A preventing TLR4 elicitation and host mimicry of the Lewis antigen decorated O-antigen of H. pylori LPS promote immune escape and chronic infection. To date, the complete structure of H. pylori LPS is not available, and the proposed model is a linear arrangement composed of the inner core defined as the hexa-saccharide (Kdo-LD-Hep-LD-Hep-DD-Hep-Gal-Glc), the outer core composed of a conserved trisaccharide (-GlcNAc-Fuc-DD-Hep-) linked to the third heptose of the inner core, the glucan, the heptan and a variable O-antigen, generally consisting of a poly-LacNAc decorated with Lewis antigens. Although the glycosyltransferases (GTs) responsible for the biosynthesis of the H. pylori O-antigen chains have been identified and characterized, there are many gaps in regard to the biosynthesis of the core LPS. These limitations warrant additional mutagenesis and structural studies to obtain the complete LPS structure and corresponding biosynthetic pathway of this important gastric bacterium.
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Affiliation(s)
- Hong Li
- West China Marshall Research Centre for Infectious Diseases, Centre of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China.,Helicobacter pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Tingting Liao
- Helicobacter pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Aleksandra W Debowski
- Helicobacter pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia.,School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Hong Tang
- West China Marshall Research Centre for Infectious Diseases, Centre of Infectious Diseases, West China Hospital of Sichuan University, Chengdu, 610041, China
| | - Hans-Olof Nilsson
- Ondek Pty Ltd., School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Keith A Stubbs
- School of Chemistry and Biochemistry, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Barry J Marshall
- Helicobacter pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia
| | - Mohammed Benghezal
- Helicobacter pylori Research Laboratory, School of Pathology & Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, The University of Western Australia, M504, L Block, QEII Medical Centre, Nedlands, WA 6009, Australia.,Swiss Vitamin Institute, Route de la Corniche 1, CH-1066, Epalinges, Switzerland
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13
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Wu Z, Liu Y, Ma C, Li L, Bai J, Byrd-Leotis L, Lasanajak Y, Guo Y, Wen L, Zhu H, Song J, Li Y, Steinhauer DA, Smith DF, Zhao B, Chen X, Guan W, Wang PG. Identification of the binding roles of terminal and internal glycan epitopes using enzymatically synthesized N-glycans containing tandem epitopes. Org Biomol Chem 2016; 14:11106-11116. [PMID: 27752690 PMCID: PMC5951163 DOI: 10.1039/c6ob01982j] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Glycans play diverse roles in a wide range of biological processes. Research on glycan-binding events is essential for learning their biological and pathological functions. However, the functions of terminal and internal glycan epitopes exhibited during binding with glycan-binding proteins (GBPs) and/or viruses need to be further identified. Therefore, a focused library of 36 biantennary asparagine (Asn)-linked glycans with some presenting tandem glycan epitopes was synthesized via a combined Core Isolation/Enzymatic Extension (CIEE) and one-pot multienzyme (OPME) synthetic strategy. These N-glycans include those containing a terminal sialyl N-acetyllactosamine (LacNAc), sialyl Lewis x (sLex) and Siaα2-8-Siaα2-3/6-R structures with N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc) sialic acid form, LacNAc, Lewis x (Lex), α-Gal, and Galα1-3-Lex; and tandem epitopes including α-Gal, Lex, Galα1-3-Lex, LacNAc, and sialyl LacNAc, presented with an internal sialyl LacNAc or 1-2 repeats of an internal LacNAc or Lex component. They were synthesized in milligram-scale, purified to over 98% purity, and used to prepare a glycan microarray. Binding studies using selected plant lectins, antibodies, and viruses demonstrated, for the first time, that when interpreting the binding between glycans and GBPs/viruses, not only the structure of the terminal glycan epitopes, but also the internal epitopes and/or modifications of terminal epitopes needs to be taken into account.
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Affiliation(s)
- Zhigang Wu
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Yunpeng Liu
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Cheng Ma
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Lei Li
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Jing Bai
- College of Life Science, Hebei Normal University, Shijiazhuang, Hebei 050024, China.
| | - Lauren Byrd-Leotis
- Departments of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yi Lasanajak
- Department of Biochemistry and Emory Comprehensive Glycomics Core, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Yuxi Guo
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Liuqing Wen
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - He Zhu
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Jing Song
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
| | - Yanhong Li
- Department of Chemistry, University of California, Davis, CA 95616, USA.
| | - David A Steinhauer
- Departments of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - David F Smith
- Department of Biochemistry and Emory Comprehensive Glycomics Core, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Baohua Zhao
- College of Life Science, Hebei Normal University, Shijiazhuang, Hebei 050024, China.
| | - Xi Chen
- Department of Chemistry, University of California, Davis, CA 95616, USA.
| | - Wanyi Guan
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA. and College of Life Science, Hebei Normal University, Shijiazhuang, Hebei 050024, China.
| | - Peng George Wang
- Department of Chemistry and Center of Diagnostics & Therapeutics, Georgia State University, Atlanta, GA 30303, USA.
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14
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Trent MS, Stead CM, Tran AX, Hankins JV. Invited review: Diversity of endotoxin and its impact on pathogenesis. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519060120040201] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Lipopolysaccharide or LPS is localized to the outer leaflet of the outer membrane and serves as the major surface component of the bacterial cell envelope. This remarkable glycolipid is essential for virtually all Gram-negative organisms and represents one of the conserved microbial structures responsible for activation of the innate immune system. For these reasons, the structure, function, and biosynthesis of LPS has been an area of intense research. The LPS of a number of bacteria is composed of three distinct regions — lipid A, a short core oligosaccharide, and the O-antigen polysaccharide. The lipid A domain, also known as endotoxin, anchors the molecule in the outer membrane and is the bioactive component recognized by TLR4 during human infection. Overall, the biochemical synthesis of lipid A is a highly conserved process; however, investigation of the lipid A structures of various organisms shows an impressive amount of diversity. These differences can be attributed to the action of latent enzymes that modify the canonical lipid A molecule. Variation of the lipid A domain of LPS serves as one strategy utilized by Gram-negative bacteria to promote survival by providing resistance to components of the innate immune system and helping to evade recognition by TLR4. This review summarizes the biochemical machinery required for the production of diverse lipid A structures of human pathogens and how structural modification of endotoxin impacts pathogenesis.
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Affiliation(s)
- M. Stephen Trent
- Department of Microbiology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA,
| | - Christopher M. Stead
- Department of Microbiology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
| | - An X. Tran
- Department of Microbiology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
| | - Jessica V. Hankins
- Department of Microbiology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
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15
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Abstract
Modification of the lipid A domain of lipopolysaccharide (LPS) has been reported to contribute to the virulence and pathogenesis of various Gram-negative bacteria. The Kdo (3-deoxy-D- manno-octulosonic acid)—lipid A domain of Helicobacter pylori LPS shows several differences to that of Escherichia coli. It has fewer acyl chains, a reduced number of phosphate groups, much lower immunobiological activity, and only a single Kdo sugar is attached to the disaccharide backbone. However, H. pylori synthesizes a minor lipid A species resembling that of E. coli, which is both bis-phosphorylated and hexa-acylated suggesting that the major species results from the action of specific modifying enzymes. This work describes two enzymes, a lipid A phosphatase and a phosphoethanolamine transferase, involved in the periplasmic modification of the 1-position of H. pylori lipid A. Furthermore, we report a novel Kdo trimming enzyme that requires prior removal of the 1-phosphate group for enzymatic activity. Discovery of the enzymatic machinery involved in the remodeling of H. pylori LPS will help unravel the importance of these modifications in H. pylori pathogenesis.
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16
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Extracellular galectin-3 counteracts adhesion and exhibits chemoattraction in Helicobacter pylori-infected gastric cancer cells. Microbiology (Reading) 2016; 162:1360-1366. [DOI: 10.1099/mic.0.000322] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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17
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The Prevalence of Helicobacter pylori Virulence Factors in Bhutan, Vietnam, and Myanmar Is Related to Gastric Cancer Incidence. BIOMED RESEARCH INTERNATIONAL 2015; 2015:830813. [PMID: 26090448 PMCID: PMC4450262 DOI: 10.1155/2015/830813] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Revised: 01/26/2015] [Accepted: 01/31/2015] [Indexed: 12/24/2022]
Abstract
Gastric cancer is a significant health problem in Asia. Although the prevalence of Helicobacter pylori infection is similar in Bhutan, Vietnam, and Myanmar, the incidence of gastric cancer is highest in Bhutan, followed by Vietnam and Myanmar. We hypothesized that H. pylori virulence factors contribute to the differences. The status of cagA, vacA, jhp0562, and β-(1,3)galT(jhp0563) was examined in 371 H. pylori-infected patients from Bhutan, Vietnam, and Myanmar. Each virulence factor could not explain the difference of the incidence of gastric cancer. However, the prevalence of quadruple-positive for cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3)galT-negative was significantly higher in Bhutan than in Vietnam and Myanmar and correlated with gastric cancer incidence. Moreover, gastritis-staging scores measured by histology of gastric mucosa were significantly higher in quadruple-positive strains. We suggest that the cagA, vacA s1, vacA m1, and jhp0562-positive/β-(1,3)galT-negative genotype may play a role in the development of gastric cancer.
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18
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Moore CJ, Auzanneau FI. Understanding the Recognition of Lewis X by Anti-Lex Monoclonal Antibodies. J Med Chem 2013; 56:8183-90. [DOI: 10.1021/jm401304h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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19
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The Role of Helicobacter pylori Outer Membrane Proteins in Adherence and Pathogenesis. BIOLOGY 2013; 2:1110-34. [PMID: 24833057 PMCID: PMC3960876 DOI: 10.3390/biology2031110] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Revised: 07/26/2013] [Accepted: 08/13/2013] [Indexed: 12/12/2022]
Abstract
Helicobacter pylori is one of the most successful human pathogens, which colonizes the mucus layer of the gastric epithelium of more than 50% of the world’s population. This curved, microaerophilic, Gram-negative bacterium induces a chronic active gastritis, often asymptomatic, in all infected individuals. In some cases, this gastritis evolves to more severe diseases such as peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. H. pylori has developed a unique set of factors, actively supporting its successful survival and persistence in its natural hostile ecological niche, the human stomach, throughout the individual’s life, unless treated. In the human stomach, the vast majority of H. pylori cells are motile in the mucus layer lining, but a small percentage adheres to the epithelial cell surfaces. Adherence to the gastric epithelium is important for the ability of H. pylori to cause disease because this intimate attachment facilitates: (1) colonization and persistence, by preventing the bacteria from being eliminated from the stomach, by mucus turnover and gastric peristalsis; (2) evasion from the human immune system and (3) efficient delivery of proteins into the gastric cell, such as the CagA oncoprotein. Therefore, bacteria with better adherence properties colonize the host at higher densities. H. pylori is one of the most genetically diverse bacterial species known and is equipped with an extraordinarily large set of outer membrane proteins, whose role in the infection and persistence process will be discussed in this review, as well as the different receptor structures that have been so far described for mucosal adherence.
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20
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Lipopolysaccharide structure of Helicobacter pylori serogroup O:3. Carbohydr Res 2013; 378:139-43. [DOI: 10.1016/j.carres.2013.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 03/05/2013] [Accepted: 03/09/2013] [Indexed: 01/26/2023]
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21
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Schur MJ, Lameignere E, Strynadka NCJ, Wakarchuk WW. Characterization of α2,3- and α2,6-sialyltransferases from Helicobacter acinonychis. Glycobiology 2012; 22:997-1006. [PMID: 22504533 DOI: 10.1093/glycob/cws071] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Genome sequence data were used to clone and express two sialyltransferase enzymes of the GT-42 family from Helicobacter acinonychis ATCC 51104, a gastric disease isolate from Cheetahs. The deposited genome sequence for these genes contains a large number of tandem repeat sequences in each of them: HAC1267 (RQKELE)(15) and HAC1268 (EEKLLEFKNI)(13). We obtained two clones with different numbers of repeat sequences for the HAC1267 gene homolog and a single clone for the HAC1268 gene homolog. Both genes could be expressed in Escherichia coli and sialyltransferase activity was measured using synthetic acceptor substrates containing a variety of terminal sugars. Both enzymes were shown to have a preference for N-acetyllactosamine, and they each made a product with a different linkage to the terminal galactose. HAC1267 is a mono-functional α2,3-sialyltransferase, whereas HAC1268 is a mono-functional α2,6-sialyltransferase and is the first member of GT-42 to show α2,6-sialyltransferase activity.
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Affiliation(s)
- Melissa J Schur
- National Research Council Canada, Institute for Biological Sciences, Ottawa, ON, Canada
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Identification and characterization of a lipopolysaccharide α,2,3-sialyltransferase from the human pathogen Helicobacter bizzozeronii. J Bacteriol 2012; 194:2540-50. [PMID: 22408169 DOI: 10.1128/jb.00126-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Terminal sialic acid in the lipopolysaccharides (LPSs) of mucosal pathogens is an important virulence factor. Here we report the characterization of a Helicobacter sialyltransferase involved in the biosynthesis of sialylated LPS in Helicobacter bizzozeronii, the only non-pylori gastric Helicobacter species isolated from humans thus far. Starting from the genome sequences of canine and human strains, we identified potential sialyltransferases downstream of three genes involved in the biosynthesis of N-acetylneuraminic acid. One of these candidates showed monofunctional α,2,3-sialyltransferase activity with a preference for N-acetyllactosamine as a substrate. The LPSs from different strains were shown by SDS-PAGE and high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) to contain sialic acid after neuraminidase treatment. The expression of this sialyltransferase and sialyl-LPS appeared to be a phase-variable characteristic common to both human and canine H. bizzozeronii strains. The sialylation site of the LPSs of two H. bizzozeronii strains was determined to be NeuAc-Hex-HexNAc, suggesting terminal 3'-sialyl-LacNAc. Moreover, serological typing revealed the possible presence of sialyl-Lewis X in two additional strains, indicating that H. bizzozeronii could also mimic the surface glycans of mammalian cells. The expression of sialyl-glycans may influence the adaptation process of H. bizzozeronii during the host jump from dogs to humans.
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Novel functions for glycosyltransferases Jhp0562 and GalT in Lewis antigen synthesis and variation in Helicobacter pylori. Infect Immun 2012; 80:1593-605. [PMID: 22290141 DOI: 10.1128/iai.00032-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lewis (Le) antigens are fucosylated oligosaccharides present in the Helicobacter pylori lipopolysaccharide. Expression of these antigens is believed to be important for H. pylori colonization, since Le antigens also are expressed on the gastric epithelia in humans. A galactosyltransferase encoded by β-(1,3)galT is essential for production of type 1 (Le(a) and Le(b)) antigens. The upstream gene jhp0562, which is present in many but not all H. pylori strains, is homologous to β-(1,3)galT but is of unknown function. Because H. pylori demonstrates extensive intragenomic recombination, we hypothesized that these two genes could undergo DNA rearrangement. A PCR screen and subsequent sequence analyses revealed that the two genes can recombine at both the 5' and 3' ends. Chimeric β-(1,3)galT-like alleles can restore function in a β-(1,3)galT null mutant, but neither native nor recombinant jhp0562 can. Mutagenesis of jhp0562 revealed that it is essential for synthesis of both type 1 and type 2 Le antigens. Transcriptional analyses of both loci showed β-(1,3)galT expression in all wild-type (WT) and mutant strains tested, whereas jhp0562 was not expressed in jhp0562 null mutants, as expected. Since jhp0562 unexpectedly displayed functions in both type 1 and type 2 Le synthesis, we asked whether galT, part of the type 2 synthesis pathway, had analogous functions in type 1 synthesis. Mutagenesis and complementation analysis confirmed that galT is essential for Le(b) production. In total, these results demonstrate that galT and jhp0562 have functions that cross the expected Le synthesis pathways and that jhp0562 provides a substrate for intragenomic recombination to generate diverse Le synthesis enzymes.
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Harrison BA, Fernández H, Chandan V, Schuster MW, Rademacher LO, Toledo C, Li J, Altman E. Characterization and functional activity of murine monoclonal antibodies specific for α1,6-glucan chain of Helicobacter pylori lipopolysaccharide. Helicobacter 2011; 16:459-67. [PMID: 22059397 DOI: 10.1111/j.1523-5378.2011.00860.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND The outer core region of H. pylori lipopolysaccharide (LPS) contains α1,6-glucan previously shown to contribute to colonizing efficiency of a mouse stomach. The aim of the present study was to generate monoclonal antibodies (mAbs) specific for α1,6-glucan and characterize their binding properties and functional activity. MATERIALS AND METHODS BALB/c mice were injected intraperitoneally with 10(8) formalin-fixed H. pylori O:3 0826::Kan cells 3× over 56 days to achieve significant titer. Anti-α1,6-glucan-producing hybridomas were screened by indirect ELISA using purified H. pylori O:3 0826::Kan LPS. One clone, 1C4F9, was selected for further characterization. The specificities of mAbs were determined by indirect and inhibition ELISA using structurally defined H. pylori LPS and synthetic oligosaccharides, and whole-cell indirect ELISA (WCE) of clinical isolates. They were further characterized by indirect immunofluorescent (IF) microscopy and their functional activity in vitro determined by serum bactericidal assays against wild-type and mutant strains of H. pylori. RESULTS The generated anti-α1,6-glucan IgM, 1C4F9, has demonstrated an excellent specificity for the glucan chain containing 5 to 6 α1,6-linked glucose residues and showed surface accessibility by IF microscopy with H. pylori cells adherent to gastric adenocarcinoma cells monolayers. Of 38 isolates from Chile, 17 strains reacted with antiglucan mAbs in WCE (OD450 ≥ 0.2). Bactericidal activity was observed against selective wild-type and mutant H. pylori strains exhibiting OD450 values of ≥ 0.45 in WCE. CONCLUSIONS Anti-α1,6-glucan mAbs could have potential application in typing and surveillance of H. pylori isolates as well as offer insights into structural requirements for the development of LPS-based vaccine against H. pylori infections.
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Affiliation(s)
- Blair A Harrison
- Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6
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Pohl MA, Zhang W, Shah SN, Sanabria-Valentín EL, Perez-Perez GI, Blaser MJ. Genotypic and phenotypic variation of Lewis antigen expression in geographically diverse Helicobacter pylori isolates. Helicobacter 2011; 16:475-81. [PMID: 22059399 PMCID: PMC3228314 DOI: 10.1111/j.1523-5378.2011.00897.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Helicobacter pylori are a persistent colonizer of the human gastric mucosa, which can lead to the development of peptic ulcer disease and gastric adenocarcinomas. However, H. pylori can asymptomatically colonize a host for years. One factor that has been hypothesized to contribute to such persistence is the production of Lewis (Le) antigens in the lipopolysaccharide layer of the bacterial outer membrane as a form of molecular mimicry, because humans also express these antigens on their gastric mucosa. Humans and H. pylori both are polymorphic for Le expression, which is driven in H. pylori by variation at the Le synthesis loci. In this report, we sought to characterize Le genotypic and phenotypic variation in geographically diverse H. pylori isolates. MATERIALS AND METHODS From patients undergoing endoscopy in 29 countries, we determined Le phenotypes of 78 H. pylori strains and performed genotyping of the galT and β-(1,3)galT loci in 113 H. pylori strains. RESULTS Le antigen phenotyping revealed a significant (p < .0001) association between type 1 (Le(a) and Le(b) ) expression and strains of East Asian origin. Genotyping revealed a significant correlation between strain origin and the size of the promoter region upstream of the Le synthesis gene, galT (p < .0001). CONCLUSION These results indicate that the heterogeneity of human Le phenotypes is reflected in their H. pylori colonizing strains and suggest new loci that can be studied to assess the variation of Le expression.
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Affiliation(s)
- Mary Ann Pohl
- Department of Medicine, New York University School of Medicine, New York, NY, USA.
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Altman E, Chandan V, Li J, Vinogradov E. Lipopolysaccharide structures of Helicobacter pylori wild-type strain 26695 and 26695 HP0826::Kan mutant devoid of the O-chain polysaccharide component. Carbohydr Res 2011; 346:2437-44. [DOI: 10.1016/j.carres.2011.06.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2011] [Revised: 06/23/2011] [Accepted: 06/28/2011] [Indexed: 10/18/2022]
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Altman E, Chandan V, Li J, Vinogradov E. A reinvestigation of the lipopolysaccharide structure of Helicobacter pylori strain Sydney (SS1). FEBS J 2011; 278:3484-93. [DOI: 10.1111/j.1742-4658.2011.08270.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Clinical relevance and diversity of two homologous genes encoding glycosyltransferases in Helicobacter pylori. J Clin Microbiol 2010; 48:2885-91. [PMID: 20554820 DOI: 10.1128/jcm.00401-10] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Helicobacter pylori is known to be a major cause of peptic ulceration. The jhp0562 gene, encoding a glycosyltransferase involved in the synthesis of the lipopolysaccharide, was associated with peptic ulcer disease (PUD) in children. The beta-(1,3)-galactosyltransferase [beta-(1,3)GalT] gene (jhp0563), involved in Lewis (Le) antigen expression, is highly similar to jhp0562. The clinical significance and diversity of both genes were examined by PCR and sequencing of clinical strains (n = 117) isolated from children with PUD (n = 57) and nonulcer dyspepsia (NUD; n = 60). The prevalence of the jhp0562 gene was significantly higher in strains with a more-virulent profile (strains positive for the cag pathogenicity island [PAI], vacA sl allele, babA, homB, phase-variable gene oipA "on" [i.e., functional], and hopQ I allele). The distribution of genotypes according to clinical outcome showed that the presence of jhp0562 represented one of the greatest risks for the development of PUD. Moreover, the triple-positive genotype for the cag PAI, jhp0562, and homB provided the best discriminatory model for distinguishing PUD and NUD outcomes in children. Sequence and in vitro expression analyses of jhp0562 showed the presence of a complete open reading frame, while the beta-(1,3)GalT gene was shown to be a phase-variable gene. The regular presence of jhp0562 in strains with a truncated beta-(1,3)GalT gene suggests that jhp0562 may also be implicated in the regulation of Le antigen expression. Overall, the results of this study suggest that the jhp0562 gene is of great clinical relevance, being a useful comarker for severe H. pylori-related disease and contributing to host adaptation.
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P-selectin-dependent platelet aggregation and apoptosis may explain the decrease in platelet count during Helicobacter pylori infection. Blood 2010; 115:4247-53. [PMID: 20097880 DOI: 10.1182/blood-2009-09-241166] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
P-selectin expression has been shown in Helicobacter pylori-infected persons, an infection that has been clinically associated with platelet-related diseases, such as idiopathic thrombocytopenic purpura. However, the role of P-selectin expression during H pylori infection remains unclear. In this study, we hypothesized that P-selectin expression was associated with platelet aggregation during H pylori infection. Using flow cytometry, we examined the levels of adhesion between H pylori and platelets as well as the levels of P-selectin expression and platelet phosphatidylserine (PS) expression during H pylori infection. Significantly high levels of adhesion between pro-aggregatory bacteria and platelets were observed. We identified that H pylori IgG is required for bacteria to induce P-selectin expression and that a significant release of P-selectin is essential for H pylori to induce aggregation. In addition, cellular apoptotic signs, such as membrane blebbing, were observed in platelet aggregates. PS expression was also detected in platelets during infection with both pro-aggrogatory and nonaggregatory strains of H pylori. These results suggest that the decrease in platelet counts seen during H pylori infection is the result of P-selection-dependent platelet aggregation and PS expression induced by the bacteria.
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Abstract
Microbial pathogens contribute to the development of more than 1 million cases of cancer per year. Gastric adenocarcinoma is the second leading cause of cancer-related death in the world, and gastritis induced by Helicobacter pylori is the strongest known risk factor for this malignancy. H. pylori colonizes the stomach for years, not days or weeks, as is usually the case for bacterial pathogens and it always induces inflammation; however, only a fraction of colonized individuals ever develop disease. Identification of mechanisms through which H. pylori co-opts host defenses to facilitate its own persistence will not only improve diagnostic and therapeutic modalities, but may also provide insights into other diseases that arise within the context of long-term pathogen-initiated inflammatory states, such as chronic viral hepatitis and hepatocellular carcinoma.
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Affiliation(s)
- Dawn A Israel
- Department of Medicine; Division of Gastroenterology; Vanderbilt University Medical Center; Nashville, TN USA
| | - Richard M Peek
- Department of Medicine; Division of Gastroenterology; Vanderbilt University Medical Center; Nashville, TN USA,Department of Cancer Biology; Vanderbilt University Medical Center; Nashville, TN USA,Department of Veterans Affairs Medical Center; Nashville, TN USA
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Abstract
Both Helicobacter pylori and Campylobacter jejuni are highly prevalent Gram-negative microaerophilic bacteria which are gastrointestinal pathogens of humans; H. pylori colonizes the gastroduodenal compartment and C. jejuni the intestinal mucosa. Although H. pylori causes chronic gastric infection leading to gastritis, peptic ulcers and eventually gastric cancer while C. jejuni causes acute infection inducing diarrhoeal disease, the endotoxin molecules of both bacterial species contrastingly contribute to their pathogenesis and the autoimmune sequelae each induces. Compared with enterobacterial endotoxin, that of H. pylori has significantly lower endotoxic and immuno-activities, the molecular basis for which is the underphosphorylation and underacylation of the lipid A component that interacts with immune receptors. This induction of low immunological responsiveness by endotoxin may aid the prolongation of H. pylori infection and therefore infection chronicity. On the other hand, this contrasts with acute infection-causing C. jejuni where overt inflammation contributes to pathology and diarrhoea production, and whose endotoxin is immunologically and endotoxically active. Futhermore, both H. pylori and C. jejuni exhibit molecular mimicry in the saccharide components of their endotoxins which can induce autoreactive antibodies; H. pylori expresses mimicry of Lewis and some ABO blood group antigens, C. jejuni mimicry of gangliosides. The former has been implicated in influencing the development of inflammation and gastric atrophy (a precursor of gastic cancer), the latter is central to the development of the neurological disorder Guillain-Barré syndrome. Both diseases raise important questions concerning infection-induced autoimmunity awaiting to be addressed.
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Affiliation(s)
- Anthony P Moran
- Laboratory of Molecular Biochemistry, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
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Hildebrandt E, McGee DJ. Helicobacter pylori lipopolysaccharide modification, Lewis antigen expression, and gastric colonization are cholesterol-dependent. BMC Microbiol 2009; 9:258. [PMID: 20003432 PMCID: PMC2804598 DOI: 10.1186/1471-2180-9-258] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Accepted: 12/14/2009] [Indexed: 12/22/2022] Open
Abstract
Background Helicobacter pylori specifically takes up cholesterol and incorporates it into the bacterial membrane, yet little is currently known about cholesterol's physiological roles. We compared phenotypes and in vivo colonization ability of H. pylori grown in a defined, serum-free growth medium, F12 with 1 mg/ml albumin containing 0 to 50 μg/ml cholesterol. Results While doubling times were largely unaffected by cholesterol, other overt phenotypic changes were observed. H. pylori strain SS1 grown in defined medium with cholesterol successfully colonized the stomach of gerbils, whereas SS1 grown without cholesterol failed to colonize. H. pylori lipopolysaccharide often displays Lewis X and/or Y antigens. Expression of these antigens measured by whole-cell ELISA was markedly enhanced in response to growth of strain SS1, 26695, or G27 in cholesterol. In addition, electrophoretic analysis of lipopolysaccharide in wild type G27 and in mutants lacking the O-chain revealed structural changes within the oligosaccharide core/lipid A moieties. These responses in Lewis antigen levels and in lipopolysaccharide profiles to cholesterol availability were highly specific, because no changes took place when cholesterol was substituted by β-sitosterol or bile salts. Disruption of the genes encoding cholesterol α-glucosyltransferase or lipid A phosphoethanolamine transferase had no effect on Lewis expression, nor on lipopolysaccharide profiles, nor on the cholesterol responsiveness of these properties. Disruption of the lipid A 1-phosphatase gene eliminated the effect of cholesterol on lipopolysaccharide profiles but not its effect on Lewis expression. Conclusions Together these results suggest that cholesterol depletion leads to aberrant forms of LPS that are dependent upon dephosphorylation of lipid A at the 1-position. A tentative model for the observed effects of cholesterol is discussed in which sequential steps of lipopolysaccharide biogenesis and, independently, presentation of Lewis antigen at the cell surface, depend upon membrane composition. These new findings demonstrate that cholesterol availability permits H. pylori to modify its cell envelope in ways that can impact colonization of host tissue in vivo.
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Affiliation(s)
- Ellen Hildebrandt
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center - Shreveport, 1501 Kings Highway, Shreveport, LA 71130, USA.
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Keenan JI, Davis KA, Beaugie CR, McGovern JJ, Moran AP. Alterations in Helicobacter pylori outer membrane and outer membrane vesicle-associated lipopolysaccharides under iron-limiting growth conditions. Innate Immun 2009; 14:279-90. [PMID: 18809652 DOI: 10.1177/1753425908096857] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Outer membrane vesicles (OMVs) shed from the gastroduodenal pathogen Helicobacter pylori have measurable effects on epithelial cell responses. The aim of this study was to determine the effect of iron availability, and its basis, on the extent and nature of lipopolysaccharide (LPS) produced on H. pylori OMVs and their parental bacterial cells. Electrophoretic, immunoblotting and structural analyses revealed that LPSs of bacterial cells grown under iron-limited conditions were notably shorter than those of bacteria and OMVs obtained from iron-replete conditions. Structural analysis and serological probing showed that LPSs of iron-replete cells and OMVs expressed O-chains of Lewis(x) with a terminal Lewis(y) unit, whereas Lewis(y) expression was notably reduced on bacteria and OMVs from iron-limiting conditions. Unlike the O-chain, the core oligosaccharide and lipid A moieties of iron-replete and iron-limited bacteria and their OMVs were similar. Quantitatively, shed OMVs from iron-replete bacteria were found to be LPSenriched, whereas shed OMVs from iron-limited bacteria had a significantly reduced content of LPS. These differences were linked to bacterial ATP levels. Since iron availability affects the extent and nature of LPS expressed by H. pylori, host iron status may contribute to H. pylori pathogenesis.
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Role for alpha-L-fucosidase in the control of Helicobacter pylori-infected gastric cancer cells. Proc Natl Acad Sci U S A 2009; 106:14581-6. [PMID: 19666478 DOI: 10.1073/pnas.0903286106] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Infecting about one-half of the global human population, Helicobacter pylori is well established as the primary cause of gastritis, duodenal ulcer, and gastric cancer. Currently there is no clear information regarding if and how host cells interact with H. pylori, and if such interactions are dependent on the type of gastric disease. Using fluorescently labeled fucose-containing glycoconjugates, we provide evidence observing both the uptake of L-fucose from gastric cancer cells to H. pylori and that human alpha-L-fucosidase 2 (FUCA2) is secreted only under coculture conditions (i.e., host cells infected with H. pylori). Upon depletion of FUCA2 by RNA interference and detection of translocated CagA (a virulence factor of H. pylori) in host cells, FUCA2 was found to be essential for H. pylori adhesion, in particular to the gastric cancer- and duodenal ulcer-specific strains. Additionally FUCA2 was shown to significantly enhance the expression of Lewis x antigen in H. pylori, which is critical for bacterial cell adhesion in the pathogenesis and defense strategy to escape host surveillance. These findings not only demonstrate an important connection between FUCA2 and the adhesion, growth, and pathogenicity of H. pylori, but also support the idea that FUCA2 is a potential target for clinical diagnosis and therapeutic intervention of H. pylori-related diseases.
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Skoglund A, Bäckhed HK, Nilsson C, Björkholm B, Normark S, Engstrand L. A changing gastric environment leads to adaptation of lipopolysaccharide variants in Helicobacter pylori populations during colonization. PLoS One 2009; 4:e5885. [PMID: 19517017 PMCID: PMC2690825 DOI: 10.1371/journal.pone.0005885] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 05/14/2009] [Indexed: 12/13/2022] Open
Abstract
The human gastric pathogen Helicobacter pylori colonizes the stomachs of half of the human population, and causes development of peptic ulcer disease and gastric adenocarcinoma. H. pylori-associated chronic atrophic gastritis (ChAG) with loss of the acid-producing parietal cells, is correlated with an increased risk for development of gastric adenocarcinoma. The majority of H. pylori isolates produce lipopolysaccharides (LPS) decorated with human-related Lewis epitopes, which have been shown to phase-vary in response to different environmental conditions. We have characterized the adaptations of H. pylori LPS and Lewis antigen expression to varying gastric conditions; in H. pylori isolates from mice with low or high gastric pH, respectively; in 482 clinical isolates from healthy individuals and from individuals with ChAG obtained at two time points with a four-year interval between endoscopies; and finally in isolates grown at different pH in vitro. Here we show that the gastric environment can contribute to a switch in Lewis phenotype in the two experimental mouse models. The clinical isolates from different human individuals showed that intra-individual isolates varied in Lewis antigen expression although the LPS diversity was relatively stable within each individual over time. Moreover, the isolates demonstrated considerable diversity in the levels of glycosylation and in the sizes of fucosylated O-antigen chains both within and between individuals. Thus our data suggest that different LPS variants exist in the colonizing H. pylori population, which can adapt to changes in the gastric environment and provide a means to regulate the inflammatory response of the host during disease progression.
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Affiliation(s)
- Anna Skoglund
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Solna, Sweden
| | - Helene Kling Bäckhed
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Solna, Sweden
| | - Christina Nilsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Solna, Sweden
| | | | - Staffan Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Solna, Sweden
| | - Lars Engstrand
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden
- Swedish Institute for Infectious Disease Control, Solna, Sweden
- * E-mail:
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Zhou P, Chandan V, Liu X, Chan K, Altman E, Li J. Microwave-assisted sample preparation for rapid and sensitive analysis of H. pylori lipid A applicable to a single colony. J Lipid Res 2009; 50:1936-44. [PMID: 19401599 DOI: 10.1194/jlr.d900013-jlr200] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The lipid A of Gram-negative bacteria plays a major role in the pathogenesis of bacterial infections. Lipid A diversity is observed both in the number and length of fatty-acid side chains and in the presence of terminal phosphate residues and associated modifications. In this report, we describe a new sample preparation method based on microwave-assisted enzymatic digestion and detergent-free mild hydrolysis, in conjunction with a MALDI-time-of-flight (TOF)/TOF analysis, to determine the structures of lipid A from Helicobacter pylori. The total time for sample preparation and mass spectrometric analysis is within 2 h and applicable to profiling the lipid A structures from dried bacterial cells on as little as 1 microg. The reliability of the technique was further demonstrated through the analysis of the lipid A from bacterial cells of different H. pylori strains. The phosphorylation and acylation patterns of lipid A could be elucidated using material from a single colony. Furthermore, we found unusual heptaacyl lipid A species present in H. pylori mutant that have not been previously reported, although the abundance was relatively low. The present study provides the first characterization of the lipid A component from a single bacterial colony sample by mass spectrometry.
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Affiliation(s)
- Ping Zhou
- Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario, Canada
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Nilsson C, Skoglund A, Moran AP, Annuk H, Engstrand L, Normark S. Lipopolysaccharide diversity evolving in Helicobacter pylori communities through genetic modifications in fucosyltransferases. PLoS One 2008; 3:e3811. [PMID: 19043574 PMCID: PMC2583950 DOI: 10.1371/journal.pone.0003811] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Accepted: 11/04/2008] [Indexed: 01/16/2023] Open
Abstract
Helicobacter pylori persistently colonizes the gastric mucosa of half the human population. It is one of the most genetically diverse bacterial organisms and subvariants are continuously emerging within an H. pylori population. In this study we characterized a number of single-colony isolates from H. pylori communities in various environmental settings, namely persistent human gastric infection, in vitro bacterial subcultures on agar medium, and experimental in vivo infection in mice. The lipopolysaccharide (LPS) O-antigen chain revealed considerable phenotypic diversity between individual cells in the studied bacterial communities, as demonstrated by size variable O-antigen chains and different levels of Lewis glycosylation. Absence of high-molecular-weight O-antigen chains was notable in a number of experimentally passaged isolates in vitro and in vivo. This phenotype was not evident in bacteria obtained from a human gastric biopsy, where all cells expressed high-molecular-weight O-antigen chains, which thus may be the preferred phenotype for H. pylori colonizing human gastric mucosa. Genotypic variability was monitored in the two genes encoding α1,3-fucosyltransferases, futA and futB, that are involved in Lewis antigen expression. Genetic modifications that could be attributable to recombination events within and between the two genes were commonly detected and created a diversity, which together with phase variation, contributed to divergent LPS expression. Our data suggest that the surrounding environment imposes a selective pressure on H. pylori to express certain LPS phenotypes. Thus, the milieu in a host will select for bacterial variants with particular characteristics that facilitate adaptation and survival in the gastric mucosa of that individual, and will shape the bacterial community structure.
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Affiliation(s)
- Christina Nilsson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
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Moran AP. Relevance of fucosylation and Lewis antigen expression in the bacterial gastroduodenal pathogen Helicobacter pylori. Carbohydr Res 2007; 343:1952-65. [PMID: 18279843 DOI: 10.1016/j.carres.2007.12.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 11/23/2007] [Accepted: 12/17/2007] [Indexed: 12/12/2022]
Abstract
Helicobacter pylori is a prevalent bacterial, gastroduodenal pathogen of humans that can express Lewis (Le) and related antigens in the O-chains of its surface lipopolysaccharide. The O-chains of H. pylori are commonly composed of internal Le(x) units with terminal Le(x) or Le(y) units or, in some strains, with additional units of Le(a), Le(b), Le(c), sialyl-Le(x) and H-1 antigens, as well as blood groups A and B, thereby producing a mosaicism of antigenic units expressed. The genetic determination of the Le antigen biosynthetic pathways in H. pylori has been studied, and despite striking functional similarity, low sequence homology occurs between the bacterial and mammalian alpha(1,3/4)- and alpha(1,2)-fucosyltransferases. Factors affecting Le antigen expression in H. pylori, that can influence the biological impact of this molecular mimicry, include regulation of fucosyltransferase genes through slipped-strand mispairing, the activity and expression levels of the functional enzymes, the preferences of the expressed enzyme for distinctive acceptor molecules and the availability of activated sugar intermediates. Le mimicry was initially implicated in immune evasion and gastric adaptation by the bacterium, but more recent studies show a role in gastric colonization and bacterial adhesion with galectin-3 identified as the gastric receptor for polymeric Le(x) on the bacterium. From the host defence aspect, innate immune recognition of H. pylori by surfactant protein D is influenced by the extent of LPS fucosylation. Furthermore, Le antigen expression affects both the inflammatory response and T-cell polarization that develops after infection. Although controversial, evidence suggests that long-term H. pylori infection can induce autoreactive anti-Le antibodies cross-reacting with the gastric mucosa, in part leading to the development of gastric atrophy. Thus, Le antigen expression and fucosylation in H. pylori have multiple biological effects on pathogenesis and disease outcome.
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Affiliation(s)
- Anthony P Moran
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland.
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Salaün L, Saunders NJ. Population-associated differences between the phase variable LPS biosynthetic genes of Helicobacter pylori. BMC Microbiol 2006; 6:79. [PMID: 16981984 PMCID: PMC1599737 DOI: 10.1186/1471-2180-6-79] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 09/18/2006] [Indexed: 11/22/2022] Open
Abstract
Background Population structures are normally determined using genes under minimal functional selection. In this study we have assessed genes that are not always essential, show differences in alleles between strains, and are involved in the directly host-selectable phenotype of LPS biosynthesis. Results Eight complete LPS biosynthesis genes, seven of which are associated with phase variation in some or all strains of Helicobacter pylori, have been sequenced and their divergence analyzed. The differences observed indicate that recombination within these genes largely reflects exchange between strains within the population lineages previously determined on the basis of MLST using housekeeping genes. This indicates that the differences that are used for MLST are likely to broadly associate with genes under functional selection, and differences in strain behaviour. However, instances of exchange between the subpopulations were identified, including the hpAfrica2 subpopulation. Further, there were other differences in gene complements and the chromosomal location of genes indicative of greater diversity within the population than is revealed by the available genome sequences and comparative genome hybridization studies. Conclusion These results indicate that the described population structure based upon MLST is broadly a good basis for studying the biology of H. pylori, but that individual alleles may not follow these associations. As a consequence, when working in unsequenced strains, it is necessary to carefully check the presence, sequence, and distribution of any individual gene of interest.
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Affiliation(s)
- Laurence Salaün
- Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
- Laboratoire des Spirochètes, 28 rue du Docteur Roux, Institut Pasteur, 75724 Paris Cedex 15, France
| | - Nigel J Saunders
- Bacterial Pathogenesis and Functional Genomics Group, The Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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Abstract
Fucosylated carbohydrate structures are involved in a variety of biological and pathological processes in eukaryotic organisms including tissue development, angiogenesis, fertilization, cell adhesion, inflammation, and tumor metastasis. In contrast, fucosylation appears less common in prokaryotic organisms and has been suggested to be involved in molecular mimicry, adhesion, colonization, and modulating the host immune response. Fucosyltransferases (FucTs), present in both eukaryotic and prokaryotic organisms, are the enzymes responsible for the catalysis of fucose transfer from donor guanosine-diphosphate fucose to various acceptor molecules including oligosaccharides, glycoproteins, and glycolipids. To date, several subfamilies of mammalian FucTs have been well characterized; these enzymes are therefore delineated and used as models. Non-mammalian FucTs that possess different domain construction or display distinctive acceptor substrate specificity are highlighted. It is noteworthy that the glycoconjugates from plants and schistosomes contain some unusual fucose linkages, suggesting the presence of novel FucT subfamilies as yet to be characterized. Despite the very low sequence homology, striking functional similarity is exhibited between mammalian and Helicobacter pylori alpha1,3/4 FucTs, implying that these enzymes likely share a conserved mechanistic and structural basis for fucose transfer; such conserved functional features might also exist when comparing other FucT subfamilies from different origins. Fucosyltranferases are promising tools used in synthesis of fucosylated oligosaccharides and glycoconjugates, which show great potential in the treatment of infectious and inflammatory diseases and tumor metastasis.
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Affiliation(s)
- Bing Ma
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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Wirth HP, Yang M, Sanabria-Valentín E, Berg DE, Dubois A, Blaser MJ. Host Lewis phenotype-dependent Helicobacter pylori Lewis antigen expression in rhesus monkeys. FASEB J 2006; 20:1534-6. [PMID: 16720729 PMCID: PMC2579782 DOI: 10.1096/fj.05-5529fje] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Both human and H. pylori populations are polymorphic for the expression of Lewis antigens. Using an experimental H. pylori challenge of rhesus monkeys of differing Lewis phenotypes, we aimed to determine whether H. pylori populations adapt their Lewis phenotypes to those of their hosts. After inoculation of four monkeys with a mixture of seven strains identified by RAPD-polymerase chain reaction, H. pylori Lewis expression was followed in 86 isolates obtained over 40 wk. Host Lewis(a/b) secretion status was characterized by immunological assays. Fingerprints of the predominating strain (J166) were identical in all four animals after 40 wk, but its Lewis phenotype had substantial variability in individual hosts. At 40 wk, J166 populations from two Lewis(a-b+) animals predominantly expressed Lewis(y). In contrast, J166 populations had switched to a Lewis(x) dominant phenotype in the two Lewis(a+b-) animals; a frame shift in futC, regulating conversion of Lewis(x) to Lewis(y), accounted for the phenotypic switch. The results indicate that individual cells in H. pylori populations can change Lewis phenotypes during long-term colonization of natural hosts to resemble those of their hosts, providing evidence for host selection for bacterial phenotypes.
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Affiliation(s)
- Hans-Peter Wirth
- Division of Infectious Diseases, Vanderbilt University School of Medicine, and VA Medical Center, Nashville, Tennessee, USA
- Division of Gastroenterology, Zurich University School of Medicine, Zurich, Switzerland
| | - Manqiao Yang
- Division of Infectious Diseases, Vanderbilt University School of Medicine, and VA Medical Center, Nashville, Tennessee, USA
- Division of Gastroenterology, Zurich University School of Medicine, Zurich, Switzerland
| | - Edgardo Sanabria-Valentín
- Departments of Medicine and Microbiology, New York University School of Medicine, and VA Medical Center, New York, New York, USA
| | - Douglas E. Berg
- Departments of Molecular Microbiology and of Genetics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - André Dubois
- Laboratory of Gastrointestinal and Liver Studies, Digestive Diseases Division, Department of Medicine, Uniformed Services of the Health Sciences, Bethesda, Maryland, USA
| | - Martin J. Blaser
- Division of Infectious Diseases, Vanderbilt University School of Medicine, and VA Medical Center, Nashville, Tennessee, USA
- Departments of Medicine and Microbiology, New York University School of Medicine, and VA Medical Center, New York, New York, USA
- Correspondence: Department of Medicine, New York University School of Medicine, 550 First Ave., New York, NY 10016, USA. E-mail:
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Fowler M, Thomas RJ, Atherton J, Roberts IS, High NJ. Galectin-3 binds to Helicobacter pylori O-antigen: it is upregulated and rapidly secreted by gastric epithelial cells in response to H. pylori adhesion. Cell Microbiol 2006; 8:44-54. [PMID: 16367865 DOI: 10.1111/j.1462-5822.2005.00599.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Helicobacter pylori causes gastritis and some infections result in peptic ulceration, gastric adenocarcinoma or gastric lymphoma. A critical step in the pathogenesis of these diseases is the ability of H. pylori to adhere to gastric epithelial cells. A role for the lipopolysaccharide O-antigen side-chain in this process has previously been identified. In this study, evidence is presented that the receptor recognized by the O-antigen side-chain is galectin-3, a beta-galactoside-binding lectin. A variety of functions have been ascribed to galectin-3 including modulation of extracellular adhesion and chemotaxis of monocytes and neutrophils. Expression of galectin-3 is upregulated by gastric epithelial cells following adhesion of H. pylori, suggesting that in addition to colonization this protein also plays a role in the host response to infection. Upregulation of galectin-3 is inhibited by treating gastric epithelial cells with the mitogen-activated protein kinase (MAPK) inhibitors U0126 or PD098059 and does not occur in cells infected with either H. pylori cagE or cagA isogenic mutants. This implies that H. pylori-mediated expression of galectin-3 is dependent on delivery of CagA into the host cell cytosol and the subsequent stimulation of MAPK signalling. A further consequence of H. pylori adhesion is that it elicits a rapid release of galectin-3 from infected cells. A role for this phenomenon in initiating the trafficking of phagocytic cells to the site of infection is discussed.
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Affiliation(s)
- Mark Fowler
- University of Manchester, Faculty of Life Science, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
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Taylor JM, Ziman ME, Huff JL, Moroski NM, Vajdy M, Solnick JV. Helicobacter pylori lipopolysaccharide promotes a Th1 type immune response in immunized mice. Vaccine 2006; 24:4987-94. [PMID: 16621176 DOI: 10.1016/j.vaccine.2006.03.043] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2006] [Revised: 03/13/2006] [Accepted: 03/16/2006] [Indexed: 12/20/2022]
Abstract
Helicobacter pylori (H. pylori) infection is prevalent worldwide and results in chronic gastritis, which may lead to peptic ulcer disease or gastric cancer. The goal of this study was to determine the role that H. pylori lipopolysaccharide (LPS) plays in stimulating host immune responses in the context of a vaccine. We compared H. pylori SS1 sonicate (LPS+) to a sonicate depleted of LPS (LPS-) in immunized BALB/c mice. Naïve splenocytes produced high levels of TNF-alpha and IL-10 after incubation with LPS+ sonicate, while cells incubated with LPS- sonicate did not. Mice immunized with LPS+ sonicate developed a prominent innate response characterized by increased TNF-alpha and IL-10, as well as a strong antigen specific Th1 response including, IFN-gamma, IL-2 and high IgG2a serum titers. Mice that received LPS- sonicate were strongly Th2 biased in their immune response, with significantly more IL-4 than IFN-gamma and serum IgG1 titers higher than IgG2a. Together these studies suggest that H. pylori LPS in a whole cell sonicate vaccine promotes a Th1 immune response that may aid in protection or clearance of H. pylori infection.
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Affiliation(s)
- Jennifer M Taylor
- Department of Internal Medicine, Center for Comparative Medicine, University of California, Davis, USA
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44
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Ma B, Audette GF, Lin S, Palcic MM, Hazes B, Taylor DE. Purification, Kinetic Characterization, and Mapping of the Minimal Catalytic Domain and the Key Polar Groups of Helicobacter pylori α-(1,3/1,4)-Fucosyltransferases. J Biol Chem 2006; 281:6385-94. [PMID: 16407247 DOI: 10.1074/jbc.m511320200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The minimal catalytic domain of alpha-(1,3/1,4)-fucosyltransferases (FucTs) from Helicobacter pylori strains NCTC11639 and UA948 was mapped by N- and C-terminal truncations. Only the C terminus could be truncated without significant loss of activity. 11639FucT and UA948FucT contain 10 and 8 heptad repeats, respectively, which connect the catalytic domain with the C-terminal putative amphipathic alpha-helices. Deletion of all heptad repeats almost completely abolished enzyme activity. Nevertheless, with only one heptad repeat 11639FucT is fully active, whereas UA948FucT is partially active. Removal of the two putative amphipathic alpha-helices dramatically increased protein expression and solubility, enabling purification with yields of milligrams/liter. Steady-state kinetic analysis of the purified FucTs showed that 11639FucTs possessed slightly tighter binding affinity for both Type II acceptor and GDP-fucose donor than UA948FucT, and its kcat of 2.3 s(-1) was double that of UA948FucT, which had a kcat value of 1.1 s(-1) for both Type II and Type I acceptors. UA948FucT strongly favors Type II over the Type I acceptor with a 20-fold difference in acceptor Km. Sixteen modified Type I and Type II series acceptors were employed to map the molecular determinants of acceptors required for recognition by H. pylori alpha-(1,3/1,4)-FucTs. Deoxygenation at 6-C of the galactose in Type II acceptor caused a 5000-fold decrease in alpha1,3 activity, whereas in Type I acceptor this completely abolished alpha1,4 activity, indicating that this hydroxyl group is a key polar group.
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Affiliation(s)
- Bing Ma
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2H7
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Nilsson C, Skoglund A, Moran AP, Annuk H, Engstrand L, Normark S. An enzymatic ruler modulates Lewis antigen glycosylation of Helicobacter pylori LPS during persistent infection. Proc Natl Acad Sci U S A 2006; 103:2863-8. [PMID: 16477004 PMCID: PMC1413829 DOI: 10.1073/pnas.0511119103] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Helicobacter pylori persistently colonizes about half the human population and contributes to the development of peptic ulcer disease and gastric cancer. This organism has evolved means to structurally alter its surface characteristics to evade innate and adaptive immune responses. H. pylori produces LPS O-antigen units that can be posttranslationally fucosylated to generate Lewis antigens, structures also found on human epithelial cells. We demonstrate an extensive diversity of Lewis x and Lewis y expression in LPS O-antigen units, occurring over time and in different regions of the human stomach. Lewis expression patterns were correlated with the on/off status of the three fucosyltransferases (FucT), FutA, FutB, and FutC, which are regulated via slipped-strand mispairing in intragenic polyC tract regions of the corresponding genes. The alpha1,3-FucT, FutA and FutB, each contain a C-terminal heptad repeat region, consisting of a variable number of DD/NLRV/INY tandem repeats. Variations in the number of heptad repeats correlated to the sizes of O-antigen polymers to become decorated by fucose residues. Our data support a molecular ruler mechanism for how H. pylori varies its LPS fucosylation pattern, where one heptad repeat in the enzyme corresponds to one N-acetyl-beta-lactosamine unit in the O-antigen polysaccharide.
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Affiliation(s)
- Christina Nilsson
- Microbiology and Tumor Biology Center, Karolinska Institutet, 171 77 Stockholm, Sweden.
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46
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Ma B, Lau LH, Palcic MM, Hazes B, Taylor DE. A single aromatic amino acid at the carboxyl terminus of Helicobacter pylori {alpha}1,3/4 fucosyltransferase determines substrate specificity. J Biol Chem 2005; 280:36848-56. [PMID: 16150700 DOI: 10.1074/jbc.m504415200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fucosyltransferases (FucT) from different Helicobacter pylori strains display distinct Type I (Galbeta1,3GlcNAc) or Type II (Galbeta1,4GlcNAc) substrate specificity. FucT from strain UA948 can transfer fucose to the OH-3 of Type II acceptors as well as to the OH-4 of Type I acceptors on the GlcNAc moiety, so it has both alpha1,3 and alpha1,4 activities. In contrast, FucT from strain NCTC11639 has exclusive alpha1,3 activity. Our domain swapping study (Ma, B., Wang, G., Palcic, M. M., Hazes, B., and Taylor, D. E. (2003) J. Biol. Chem. 278, 21893-21900) demonstrated that exchange of the hypervariable loops, (347)DNPFIFC(353) in 11639FucT and (345)CNDAHYSALH(354) in UA948FucT, were sufficient to either confer or abolish alpha1,4 activity. Here we performed alanine scanning site-directed mutagenesis to identify which amino acids within (345)CNDAHYSALH(354) of UA948FucT confer Type I substrate specificity. The Tyr(350) --> Ala mutation dramatically reduced alpha1,4 activity without lowering alpha1,3 activity. None of the other alanine substitutions selectively eliminated alpha1,4 activity. To elucidate how Tyr(350) determines alpha1,4 specificity, mutants Tyr(350) --> Phe, Tyr(350) --> Trp, and Tyr(350) --> Gly were constructed in UA948FucT. These mutations did not decrease alpha1,3 activity but reduced the alpha1,4 activity to 66.9, 55.6, and 3.1% [corrected] of wild type level, respectively. Apparently the aromatic nature, but not the hydroxyl group of Tyr(350), is essential for alpha1,4 activity. Our data demonstrate that a single amino acid (Tyr(350)) in the C-terminal hypervariable region of UA948FucT determines Type I acceptor specificity. Notably, a single aromatic residue (Trp) has also been implicated in controlling Type I acceptor preference for human FucT III, but it is located in an N-terminal hypervariable stem domain.
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Affiliation(s)
- Bing Ma
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Langdon R, Craig JE, Goldrick M, Houldsworth R, High NJ. Analysis of the role of HP0208, a phase-variable open reading frame, and its homologues HP1416 and HP0159 in the biosynthesis of Helicobacter pylori lipopolysaccharide. J Med Microbiol 2005; 54:697-706. [PMID: 16014421 DOI: 10.1099/jmm.0.45842-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The roles of the three ORFs HP0208, HP0159 and HP1416 in the biosynthesis of Helicobacter pylori 26695 LPS were investigated in this study. These ORFs represent a paralogous family of genes with homology to the Salmonella enterica serovar Typhimurium (hereafter referred to as S. typhimurium) waaJ gene, which encodes an alpha-1,2-glycosyltransferase required for core LPS biosynthesis. HP0208 contains multiple tandem repeats of the dimer 5'GA at its 5' end and its expression is predicted to be subject to phase variation. The number of 5'GA repeats present in this ORF was found to be non-permissive for the expression of HP0208 in the majority of H. pylori strains examined. To determine a role for this ORF in LPS biosynthesis a non-phase-variable, constitutively expressed variant of HP0208 was constructed and introduced into the genome of H. pylori 26695. Analysis of the LPS profile of this strain by Tricine-SDS-PAGE and immunoblotting with anti-Lewis Y antigen (Le(y)) mAbs confirmed a role for HP0208 in the biosynthesis of core LPS. A role for HP0159 and HP1416 in the biosynthesis of core LPS was also established. Although homologous to waaJ, H. pylori HP0208, HP0159 and HP1416 failed to complement an S. typhimurium waaJ mutant, suggesting that these ORFs encode functionally different enzymes.
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Affiliation(s)
- Rebecca Langdon
- University of Manchester, Faculty of Life Sciences, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Jane E Craig
- University of Manchester, Faculty of Life Sciences, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Marie Goldrick
- University of Manchester, Faculty of Life Sciences, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Rebecca Houldsworth
- University of Manchester, Faculty of Life Sciences, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
| | - Nicola J High
- University of Manchester, Faculty of Life Sciences, 1.800 Stopford Building, Oxford Road, Manchester M13 9PT, UK
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Stead C, Tran A, Ferguson D, McGrath S, Cotter R, Trent S. A novel 3-deoxy-D-manno-octulosonic acid (Kdo) hydrolase that removes the outer Kdo sugar of Helicobacter pylori lipopolysaccharide. J Bacteriol 2005; 187:3374-83. [PMID: 15866922 PMCID: PMC1111988 DOI: 10.1128/jb.187.10.3374-3383.2005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The lipid A domain anchors lipopolysaccharide (LPS) to the outer membrane and is typically a disaccharide of glucosamine that is both acylated and phosphorylated. The core and O-antigen carbohydrate domains are linked to the lipid A moiety through the eight-carbon sugar 3-deoxy-D-manno-octulosonic acid known as Kdo. Helicobacter pylori LPS has been characterized as having a single Kdo residue attached to lipid A, predicting in vivo a monofunctional Kdo transferase (WaaA). However, using an in vitro assay system we demonstrate that H. pylori WaaA is a bifunctional enzyme transferring two Kdo sugars to the tetra-acylated lipid A precursor lipid IV(A). In the present work we report the discovery of a Kdo hydrolase in membranes of H. pylori capable of removing the outer Kdo sugar from Kdo2-lipid A. Enzymatic removal of the Kdo group was dependent upon prior removal of the 1-phosphate group from the lipid A domain, and mass spectrometric analysis of the reaction product confirmed the enzymatic removal of a single Kdo residue by the Kdo-trimming enzyme. This is the first characterization of a Kdo hydrolase involved in the modification of gram-negative bacterial LPS.
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Affiliation(s)
- Christopher Stead
- Department of Microbiology, J. H. Quillen College of Medicine, Johnson City, Tennessee 37614, USA
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Logan SM, Altman E, Mykytczuk O, Brisson JR, Chandan V, Schur MJ, St Michael F, Masson A, Leclerc S, Hiratsuka K, Smirnova N, Li J, Wu Y, Wakarchuk WW. Novel biosynthetic functions of lipopolysaccharide rfaJ homologs from Helicobacter pylori. Glycobiology 2005; 15:721-33. [PMID: 15814825 DOI: 10.1093/glycob/cwi057] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Activity screening and insertional inactivation of lipopolysaccharide (LPS) biosynthetic genes in Helicobacter pylori have led to the successful characterization of two key enzymes encoded by HP0159 (JHP0147) and HP1105 (JHP1032) open reading frames (ORFs) which are members of the large and diverse carbohydrate active enzymes (CAZY) GT-8 (rfaJ) family of glycosyltransferases. Activity screening of a genomic library led to the identification of the enzyme involved in the biosynthesis of the type 2 N-acetyl-lactosamine O-chain backbone, the beta-1,3-N-acetyl-glucosaminyl transferase. In addition, the activity screening approach led to the identification and characterization of a key core biosynthetic enzyme responsible for the biosynthesis of the alpha-1,6-glucan polymer. This alpha-1,6-glucosyltransferase protein is encoded by the HP0159 ORF. Both enzymes play an integral part in the biosynthesis of LPS, and insertional inactivation leads to the production of a truncated LPS molecule on the bacterial cell surface. The LPS structures were determined by mass spectrometry and chemical analyses. The linkage specificity of each glycosyltransferase was determined by nuclear magnetic resonance (NMR) analysis of model compounds synthesized in vitro. A cryogenic probe was used to structurally characterize nanomole amounts of the product of the HP1105 (JHP1032) enzyme. In contrast to the HP0159 enzyme, which displays the GT-8-predicted retaining stereochemistry for the reaction product, HP1105 (JHP1032) is the first member of this GT-8 family to have been shown to have an inverting stereochemistry in its reaction products.
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Affiliation(s)
- Susan M Logan
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada K1A OR6.
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50
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Hynes SO, Keenan JI, Ferris JA, Annuk H, Moran AP. Lewis epitopes on outer membrane vesicles of relevance to Helicobacter pylori pathogenesis. Helicobacter 2005; 10:146-56. [PMID: 15810946 DOI: 10.1111/j.1523-5378.2005.00302.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Helicobacter pylori extrudes protein- and lipopolysaccharide-enriched outer membrane vesicles from its cell surface which have been postulated to act to deliver virulence factors to the host. Lewis antigen expression by lipopolysaccharide of H. pylori cells has been implicated in a number of pathogenic roles. The aim of this study was to further characterize the expression of lipopolysaccharide on the surface of these outer membrane vesicles and, in particular, expression of Lewis antigens and their association with antibody production in the host. MATERIALS AND METHODS H. pylori strains were examined for outer membrane vesicle production using transmission electron microscopy and Lewis antigen expression probed using immunoelectron microscopy. Sera from patients were analyzed for cross-reacting anti-Lewis antibodies and, subsequently, absorbed using outer membrane vesicle preparations to remove the cross-reacting antibodies. RESULTS The formation of outer membrane vesicles by H. pylori was observed in both in vitro and in vivo samples. Furthermore, vesicles were produced following culture in either liquid or solid medium by all strains examined. Moreover, we observed the presence of Lewis epitopes on outer membrane vesicles using immunoelectron microscopy and immunoblotting. Circulating anti-Lewis antibodies were found in the sera of gastric cancer patients but not in the sera of H. pylori-negative control subjects. Absorption of patient sera with outer membrane vesicles decreased the levels of anti-Lewis autoantibodies. CONCLUSIONS Our results demonstrate the ability of H. pylori to generate outer membrane vesicles bearing serologically recognizable Lewis antigens on lipopolysaccharide molecules which may contribute to the chronic immune stimulation of the host. The ability of these vesicles to absorb anti-Lewis autoantibodies indicates that they may, in part, play a role in putative autoimmune aspects of H. pylori pathogenesis.
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Affiliation(s)
- Sean O Hynes
- Department of Microbiology, National University of Ireland, Galway, Ireland
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