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Pellegrinelli V, Rodriguez-Cuenca S, Rouault C, Figueroa-Juarez E, Schilbert H, Virtue S, Moreno-Navarrete JM, Bidault G, Vázquez-Borrego MC, Dias AR, Pucker B, Dale M, Campbell M, Carobbio S, Lin YH, Vacca M, Aron-Wisnewsky J, Mora S, Masiero MM, Emmanouilidou A, Mukhopadhyay S, Dougan G, den Hoed M, Loos RJF, Fernández-Real JM, Chiarugi D, Clément K, Vidal-Puig A. Dysregulation of macrophage PEPD in obesity determines adipose tissue fibro-inflammation and insulin resistance. Nat Metab 2022; 4:476-494. [PMID: 35478031 DOI: 10.1038/s42255-022-00561-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 03/18/2022] [Indexed: 02/02/2023]
Abstract
Resulting from impaired collagen turnover, fibrosis is a hallmark of adipose tissue (AT) dysfunction and obesity-associated insulin resistance (IR). Prolidase, also known as peptidase D (PEPD), plays a vital role in collagen turnover by degrading proline-containing dipeptides but its specific functional relevance in AT is unknown. Here we show that in human and mouse obesity, PEPD expression and activity decrease in AT, and PEPD is released into the systemic circulation, which promotes fibrosis and AT IR. Loss of the enzymatic function of PEPD by genetic ablation or pharmacological inhibition causes AT fibrosis in mice. In addition to its intracellular enzymatic role, secreted extracellular PEPD protein enhances macrophage and adipocyte fibro-inflammatory responses via EGFR signalling, thereby promoting AT fibrosis and IR. We further show that decreased prolidase activity is coupled with increased systemic levels of PEPD that act as a pathogenic trigger of AT fibrosis and IR. Thus, PEPD produced by macrophages might serve as a biomarker of AT fibro-inflammation and could represent a therapeutic target for AT fibrosis and obesity-associated IR and type 2 diabetes.
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Affiliation(s)
- V Pellegrinelli
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK.
| | - S Rodriguez-Cuenca
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Cambridge University Nanjing Centre of Technology and Innovation, Nanjing, P. R. China
| | - C Rouault
- Sorbonne University, INSERM, NutriOmique Research Unit, Paris, France
| | - E Figueroa-Juarez
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - H Schilbert
- Genetics and Genomics of Plants, Centre for Biotechnology (CeBiTec) & Faculty of Biology, Bielefeld University, Bielefeld, Germany
| | - S Virtue
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - J M Moreno-Navarrete
- Department of Diabetes, Endocrinology and Nutrition, Girona Biomedical Research Institute (IDIBGI), University Hospital of Girona Dr Josep Trueta, Girona, Spain
- Department of Medicine, University of Girona, Girona, Spain
- CIBERobn Pathophysiology of Obesity and Nutrition, Institut of Salud Carlos III, Madrid, Spain
| | - G Bidault
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - M C Vázquez-Borrego
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Maimonides Institute for Biomedical Research of Cordoba (IMIBIC), Cordoba, Spain
| | - A R Dias
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - B Pucker
- Genetics and Genomics of Plants, Centre for Biotechnology (CeBiTec) & Faculty of Biology, Bielefeld University, Bielefeld, Germany
- Evolution and Diversity, Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - M Dale
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - M Campbell
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Cambridge University Nanjing Centre of Technology and Innovation, Nanjing, P. R. China
| | - S Carobbio
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Centro de Investigacion Principe Felipe, Valencia, Spain
| | - Y H Lin
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Department of Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - M Vacca
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
- Insterdisciplinary Department of Medicine, Università degli Studi di Bari 'Aldo Moro', Bari, Italy
| | - J Aron-Wisnewsky
- Sorbonne University, INSERM, NutriOmique Research Unit, Paris, France
- Assistance-Publique Hôpitaux de Paris, Nutrition department, Pitié-Salpêtrière hospital, Paris, France
| | - S Mora
- Dept Biochemistry and Molecular Biomedicine, Faculty of Biology, University of Barcelona, Barcelona, Spain
- Institute of Biomedicine, University of Barcelona (IBUB), Barcelona, Spain
| | - M M Masiero
- The Beijer Laboratory and Department of Immunology, Genetics and Pathology, Uppsala University and SciLifeLab, Uppsala, Sweden
| | - A Emmanouilidou
- The Beijer Laboratory and Department of Immunology, Genetics and Pathology, Uppsala University and SciLifeLab, Uppsala, Sweden
| | - S Mukhopadhyay
- MRC Centre for Transplantation Peter Gorer Department of Immunobiology School of Immunology & Microbial Sciences King's College, London, UK
| | - G Dougan
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, Jeffrey Cheah Biomedical Centre, University of Cambridge, Cambridge, UK
- Division of Infectious Diseases, Department of Medicine, University of Cambridge, Cambridge, UK
| | - M den Hoed
- The Beijer Laboratory and Department of Immunology, Genetics and Pathology, Uppsala University and SciLifeLab, Uppsala, Sweden
| | - R J F Loos
- Charles Bronfman Institute for Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Science, University of Copenhagen, Copenhagen, Denmark
| | - J M Fernández-Real
- Department of Diabetes, Endocrinology and Nutrition, Girona Biomedical Research Institute (IDIBGI), University Hospital of Girona Dr Josep Trueta, Girona, Spain
- Department of Medicine, University of Girona, Girona, Spain
- CIBERobn Pathophysiology of Obesity and Nutrition, Institut of Salud Carlos III, Madrid, Spain
| | - D Chiarugi
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK
| | - K Clément
- Sorbonne University, INSERM, NutriOmique Research Unit, Paris, France
- Assistance-Publique Hôpitaux de Paris, Nutrition department, Pitié-Salpêtrière hospital, Paris, France
| | - A Vidal-Puig
- Wellcome-MRC Institute of Metabolic Science and MRC Metabolic Diseases Unit, University of Cambridge, Cambridge, UK.
- Cambridge University Nanjing Centre of Technology and Innovation, Nanjing, P. R. China.
- Centro de Investigacion Principe Felipe, Valencia, Spain.
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Pragasam A, Mutreja A, John J, Anandan S, Mohan V, Kang G, Dougan G, Veeraraghavan B. Genomic investigations of S. Typhi isolated from Community and Hospital settings – An update from SEFI network. Int J Infect Dis 2020. [DOI: 10.1016/j.ijid.2020.09.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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3
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Ashton PM, Thanh LT, Trieu PH, Van Anh D, Trinh NM, Beardsley J, Kibengo F, Chierakul W, Dance DAB, Rattanavong S, Davong V, Hung LQ, Chau NVV, Tung NLN, Chan AK, Thwaites GE, Lalloo DG, Anscombe C, Nhat LTH, Perfect J, Dougan G, Baker S, Harris S, Day JN. Three phylogenetic groups have driven the recent population expansion of Cryptococcus neoformans. Nat Commun 2019; 10:2035. [PMID: 31048698 PMCID: PMC6497710 DOI: 10.1038/s41467-019-10092-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 04/15/2019] [Indexed: 01/04/2023] Open
Abstract
Cryptococcus neoformans (C. neoformans var. grubii) is an environmentally acquired pathogen causing 181,000 HIV-associated deaths each year. We sequenced 699 isolates, primarily C. neoformans from HIV-infected patients, from 5 countries in Asia and Africa. The phylogeny of C. neoformans reveals a recent exponential population expansion, consistent with the increase in the number of susceptible hosts. In our study population, this expansion has been driven by three sub-clades of the C. neoformans VNIa lineage; VNIa-4, VNIa-5 and VNIa-93. These three sub-clades account for 91% of clinical isolates sequenced in our study. Combining the genome data with clinical information, we find that the VNIa-93 sub-clade, the most common sub-clade in Uganda and Malawi, was associated with better outcomes than VNIa-4 and VNIa-5, which predominate in Southeast Asia. This study lays the foundation for further work investigating the dominance of VNIa-4, VNIa-5 and VNIa-93 and the association between lineage and clinical phenotype.
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Affiliation(s)
- P M Ashton
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | - L T Thanh
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
| | - P H Trieu
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
| | - D Van Anh
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
| | - N M Trinh
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
| | - J Beardsley
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
- Marie Bashir Institute, University of Sydney, Sydney, 2050, NSW, Australia
| | - F Kibengo
- MRC/UVRI and LSHTM Uganda Research Unit, Entebbe, Uganda
| | - W Chierakul
- Mahidol Oxford Tropical Medicine Research Unit, Bangkok, Thailand
| | - D A B Dance
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - S Rattanavong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
| | - V Davong
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Laos
| | - L Q Hung
- Cho Ray Hospital, Ho Chi Minh City, Vietnam
| | - N V V Chau
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - N L N Tung
- Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - A K Chan
- Sunnybrook Health Sciences Centre, University of Toronto, Toronto, M4N 3M5, ON, Canada
- Dignitas International, Zomba, Malawi
| | - G E Thwaites
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | - D G Lalloo
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - C Anscombe
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
| | - L T H Nhat
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
| | - J Perfect
- Department of Medicine and Department of Molecular Genetics and Microbiology, Division of Infectious Diseases, Duke University, Durham, NC, 27710, USA
| | - G Dougan
- Wellcome Trust-Cambridge Centre for Global Health Research, Cambridge, CB2 0XY, UK
- Pathogen Genomics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, CB10 1SA, Cambridgeshire, UK
- Department of Medicine, University of Cambridge, Cambridge, CB2 0SP, UK
| | - S Baker
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK
- Wellcome Trust-Cambridge Centre for Global Health Research, Cambridge, CB2 0XY, UK
- Department of Medicine, University of Cambridge, Cambridge, CB2 0SP, UK
| | - S Harris
- Pathogen Genomics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, CB10 1SA, Cambridgeshire, UK
| | - J N Day
- Wellcome Trust Asia Programme, Oxford University Clinical Research Unit, 764 Vo Van Kiet, Ho Chi Minh City, Vietnam.
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, OX3 7FZ, UK.
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Wilson H, Khokhar F, Enoch D, Brown N, Ahluwalia J, Dougan G, Török M. Point-prevalence survey of carbapenemase-producing Enterobacteriaceae and vancomycin-resistant enterococci in adult inpatients in a university teaching hospital in the UK. J Hosp Infect 2018; 100:35-39. [DOI: 10.1016/j.jhin.2018.06.024] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 06/27/2018] [Indexed: 10/28/2022]
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5
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Cabello FC, Cohen SN, Curtiss R, Dougan G, van Embden J, Finlay BB, Heffron F, Helinski D, Hull R, Hull S, Isberg R, Kopecko DJ, Levy S, Mekalanos J, Ortiz JM, Rappuoli R, Roberts MC, So M, Timmis KN. Farewell Stan Stanley Falkow: 1934-2018. Environ Microbiol 2018; 20:2322-2333. [PMID: 30146753 DOI: 10.1111/1462-2920.14308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- F C Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA
| | - S N Cohen
- Department of Genetics, Stanford University, Stanford, CA, USA
| | - R Curtiss
- Departments of Infectious Diseases and Immunology and Comparative, Diagnostic and Population Medicine, University of Florida, Gainesville, FL, USA
| | - G Dougan
- Microbial Pathogenesis Group, Welcome Sanger Institute, Hinxton, UK
| | - J van Embden
- Division of Infectious Diseases, National Institute of Public Health and the Environment, Bilthoven, The Netherlands
| | - B B Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - F Heffron
- Department of Molecular Microbiology and Immunology, Oregon Health and Science University, Portland, OR, USA
| | - D Helinski
- Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - R Hull
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - S Hull
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - R Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| | | | - S Levy
- Department of Molecular Biology and Microbiology, Tufts University, Boston, MA, USA
| | - J Mekalanos
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
| | - J M Ortiz
- Departamento de Biologia Molecular, Universidad de Cantabria, Santander, Spain
| | | | - M C Roberts
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA
| | - M So
- Department of Immunobiology, University of Arizona, Tucson, AZ, USA
| | - K N Timmis
- Institute of Microbiology, Technical University of Braunschweig, Braunschweig, Germany
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6
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Everitt A, Clare S, Pertel T, John S, Wash R, Smith S, Chin C, Feeley E, Simms J, Adams D, Wise H, Kane L, Goulding D, Digard P, Anttila V, Baillie K, Walsh T, Hume D, Palotie A, Xue Y, Colonna V, Tyler-Smith C, Dunning J, Gordon S, Smyth R, Openshaw P, Dougan G, Brass A, Kellam P. IFITM3 restricts the morbidity and mortality associated with influenza. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.191] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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7
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Waddington C, Darton T, Jones C, Haworth K, Peters A, Kerridge S, Crook D, Lockhart S, Farrar J, Dougan G, Levine M, Angus B, Pollard A. Variations in attack rate in a single-blind, dose escalation challenge study of Salmonella Typhi in healthy adult volunteers. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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8
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Darton T, Jones C, Waddington C, Dougan G, Sztein M, Levine M, Angus B, Farrar J, Lockhart S, Crook D, Pollard A, Zhou L. Demonstration of primary and asymptomatic DNAaemia in participants challenged with Salmonella Typhi (Quailes strain) during the development of a human model of typhoid infection. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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9
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Jones C, Waddington C, Darton T, Bowman J, Farrar J, Dougan G, Levine M, Lockhart S, Sztein M, Crook D, Angus B, Pollard A. Quantification of antibody secreting cell responses in a human challenge model of Salmonella Typhi infection. Int J Infect Dis 2012. [DOI: 10.1016/j.ijid.2012.05.826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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10
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Bhattacharya S, Black R, Bourgeois L, Clemens J, Cravioto A, Deen JL, Dougan G, Glass R, Grais RF, Greco M, Gust I, Holmgren J, Kariuki S, Lambert PH, Liu MA, Longini I, Nair GB, Norrby R, Nossal GJV, Ogra P, Sansonetti P, von Seidlein L, Songane F, Svennerholm AM, Steele D, Walker R. The Cholera Crisis in Africa. Science 2009; 324:885. [DOI: 10.1126/science.1173890] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Khan S, Chatfield S, Stratford R, Bedwell J, Bentley M, Sulsh S, Giemza R, Smith S, Bongard E, Cosgrove C, Johnson J, Dougan G, Griffin G, Makin J, Lewis D. Ability of SPI2 mutant of S. typhi to effectively induce antibody responses to the mucosal antigen enterotoxigenic E. coli heat labile toxin B subunit after oral delivery to humans. Vaccine 2007; 25:4175-82. [PMID: 17412462 PMCID: PMC2652036 DOI: 10.1016/j.vaccine.2007.03.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 03/05/2007] [Accepted: 03/05/2007] [Indexed: 12/01/2022]
Abstract
We have evaluated an oral vaccine based on an Salmonella enteric serovar typhi (S. typhi) Ty2 derivative TSB7 harboring deletion mutations in ssaV (SPI-2) and aroC together with a chromosomally integrated copy of eltB encoding the B subunit of enterotoxigenic Escherichia coli heat labile toxin (LT-B) in volunteers. Two oral doses of 10(8) or 10(9)CFU were administered to two groups of volunteers and both doses were well tolerated, with no vaccinemia, and only transient stool shedding. Immune responses to LT-B and S. typhi lipopolysaccharide were demonstrated in 67 and 97% of subjects, respectively, without evidence of anti-carrier immunity preventing boosting of LT-B responses in many cases. Further development of this salmonella-based (spi-VEC) system for oral delivery of heterologous antigens appears warranted.
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Affiliation(s)
- S. Khan
- Microscience, Wokingham Berkshire RG41 5TU, UK
| | | | | | - J. Bedwell
- Microscience, Wokingham Berkshire RG41 5TU, UK
| | - M. Bentley
- Microscience, Wokingham Berkshire RG41 5TU, UK
| | - S. Sulsh
- Microscience, Wokingham Berkshire RG41 5TU, UK
| | - R. Giemza
- St. George's Vaccine Institute, London SW17 0RE, UK
| | - S. Smith
- St. George's Vaccine Institute, London SW17 0RE, UK
| | - E. Bongard
- St. George's Vaccine Institute, London SW17 0RE, UK
| | | | - J. Johnson
- St. George's Vaccine Institute, London SW17 0RE, UK
| | - G. Dougan
- The Wellcome Trust Sanger Institute, Genome Campus, Cambridge CB10 1SA, UK
| | - G.E. Griffin
- St. George's Vaccine Institute, London SW17 0RE, UK
| | - J. Makin
- Microscience, Wokingham Berkshire RG41 5TU, UK
| | - D.J.M. Lewis
- St. George's Vaccine Institute, London SW17 0RE, UK
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van Diemen PM, Dziva F, Abu-Median A, Wallis TS, van den Bosch H, Dougan G, Chanter N, Frankel G, Stevens MP. Subunit vaccines based on intimin and Efa-1 polypeptides induce humoral immunity in cattle but do not protect against intestinal colonisation by enterohaemorrhagic Escherichia coli O157:H7 or O26:H-. Vet Immunol Immunopathol 2007; 116:47-58. [PMID: 17258324 PMCID: PMC2656997 DOI: 10.1016/j.vetimm.2006.12.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2006] [Revised: 12/19/2006] [Accepted: 12/29/2006] [Indexed: 11/17/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) infections in humans are an important public health concern and are commonly acquired via contact with ruminant faeces. Cattle are a key control point however cross-protective vaccines for the control of EHEC in the bovine reservoir do not yet exist. The EHEC serogroups that are predominantly associated with human infection in Europe and North America are O157 and O26. Intimin and EHEC factor for adherence (Efa-1) play important roles in intestinal colonisation of cattle by EHEC and are thus attractive candidates for the development of subunit vaccines. Immunisation of calves with the cell-binding domain of intimin subtypes β or γ via the intramuscular route induced antigen-specific serum IgG1 and, in some cases salivary IgA responses, but did not reduce the magnitude or duration of faecal excretion of EHEC O26:H- (Int280-β) or EHEC O157:H7 (Int280-γ) upon subsequent experimental challenge. Similarly, immunisation of calves via the intramuscular route with the truncated Efa-1 protein (Efa-1′) from EHEC O157:H7 or a mixture of the amino-terminal and central thirds of the full-length protein (Efa-1-N and M) did not protect against intestinal colonisation by EHEC O157:H7 (Efa-1′) or EHEC O26:H- (Efa-1-N and M) despite the induction of humoral immunity. A portion of the serum IgG1 elicited by the truncated recombinant antigens in calves was confirmed to recognise native protein exposed on the bacterial surface. Calves immunised with a mixture of Int280-γ and Efa-1′ or an EHEC O157:H7 bacterin via the intramuscular route then boosted via the intranasal route with the same antigens using cholera toxin B subunit as an adjuvant were also not protected against intestinal colonisation by EHEC O157:H7. These studies highlight the need for further studies to develop and test novel vaccines or treatments for control of this important foodborne pathogen.
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Affiliation(s)
- P M van Diemen
- Institute for Animal Health, Compton, Berkshire RG20 7NN, UK.
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13
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Cahill RJ, Tan S, Dougan G, O'Gaora P, Pickard D, Kennea N, Sullivan MHF, Feldman RG, Edwards AD. Universal DNA primers amplify bacterial DNA from human fetal membranes and link Fusobacterium nucleatum with prolonged preterm membrane rupture. Mol Hum Reprod 2005; 11:761-6. [PMID: 16254004 DOI: 10.1093/molehr/gah234] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A large number of bacterial species have been identified in fetal membranes after preterm labour (PTL) associated with intrauterine infection by microbiological culture. In this study, we have investigated a molecular and bioinformatic approach to organism identification which surmounts the need for specific and diverse microbiological culture conditions required by conventional methods. Samples of fetal membranes were taken from 37 preterm infants, and 6 normal term controls delivered by caesarean section, in which bacteria had been detected by in situ hybridization of 16S ribosomal RNA using a generic probe. Degenerate primers were designed to amplify bacterial 16S ribosomal DNA by PCR and used to amplify bacterial DNA from human fetal membranes. Amplicons were cloned, sequenced and bacteria were identified bioinformatically by comparison of sequences with known bacterial DNA genomes. In situ hybridization using an organism specific probe was then used to confirm the presence of the commonest identified organism in tissue samples. Bacterial DNA amplified from 15/43 samples, all from preterm deliveries, and the bioinformatic approach identified organisms in all cases. Multiple bacteria were identified including Mycoplasma hominis, Pasturella multocida, Pseudomonas PH1, Escherichia coli and Prevotella bivia. The commonest organism Fusobacterium nucleatum was found in 9/15 (60%) of samples. Ten of the 12 samples obtained after prolonged membrane rupture were positive for bacterial DNA, and 7 of these (70%) contained DNA from F. nucleatum. Bacteria from fetal membranes may be identified by molecular and bioinformatic methods. Further work is warranted to investigate the apparent linkage between F. nucleatum, fetal membrane rupture and preterm delivery.
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MESH Headings
- Bacterial Typing Techniques
- DNA Primers
- DNA, Bacterial/analysis
- DNA, Bacterial/genetics
- DNA, Bacterial/metabolism
- DNA, Ribosomal/analysis
- DNA, Ribosomal/genetics
- DNA, Ribosomal/metabolism
- Extraembryonic Membranes/microbiology
- Female
- Fetal Membranes, Premature Rupture/microbiology
- Fusobacterium nucleatum/classification
- Fusobacterium nucleatum/genetics
- Fusobacterium nucleatum/isolation & purification
- Humans
- In Situ Hybridization, Fluorescence
- Infant, Newborn
- Infant, Premature
- Polymerase Chain Reaction
- Pregnancy
- Pregnancy Outcome
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Affiliation(s)
- R J Cahill
- Department of Biological Sciences, Centre for Molecular Microbiology and Infection, Flowers Building, London, UK
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14
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Wiles S, Clare S, Harker J, Huett A, Young D, Dougan G, Frankel G. Organ-specificity, colonization and clearance dynamics in vivo following oral challenges with the murine pathogen Citrobacter rodentium. Cell Microbiol 2005. [DOI: 10.1111/j.1462-5822.2004.00479.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Shaw DJ, Jenkins C, Pearce MC, Cheasty T, Gunn GJ, Dougan G, Smith HR, Woolhouse MEJ, Frankel G. Shedding patterns of verocytotoxin-producing Escherichia coli strains in a cohort of calves and their dams on a Scottish beef farm. Appl Environ Microbiol 2005; 70:7456-65. [PMID: 15574948 PMCID: PMC535143 DOI: 10.1128/aem.70.12.7456-7465.2004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rectal fecal samples were taken once a week from 49 calves on the same farm. In addition, the dams of the calves were sampled at the time of calf birth and at the end of the study. Strains of verocytotoxin-producing Escherichia coli (VTEC) were isolated from these samples by using PCR and DNA probe hybridization tests and were characterized with respect to serotype, verocytotoxin gene (vtx) type, and the presence of the intimin (eae) and hemolysin (ehxA) genes. A total of 170 VTEC strains were isolated during 21 weeks from 130 (20%) of 664 samples from calves and from 40 (47%) of 86 samples from their dams. The characteristics of the calf strains differed from those strains isolated from the dams with respect to verocytotoxin 2 and the presence of the eae gene. In addition, no calf shed the same VTEC serogroup (excluding O?) as its dam at birth or at the end of the study. The most frequently detected serogroups in calves were serogroup O26 and provisional serogroup E40874 (VTEC O26 was found in 25 calves), whereas in dams serogroup O91 and provisional serogroup E54071 were the most common serogroups. VTEC O26 shedding appeared to be associated with very young calves and declined as the calves aged, whereas VTEC O2 shedding was associated with housing of the animals. VTEC O26 strains from calves were characterized by the presence of the vtx1, eae, and ehxA genes, whereas vtx2 was associated with VTEC O2 and provisional serogroup E40874. The high prevalence of VTEC O26 and of VTEC strains harboring the eae gene in this calf cohort is notable because of the association of the O26 serogroup and the presence of the eae gene with human disease. No association between calf diarrhea and any of the VTEC serogroups was identified.
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Affiliation(s)
- D J Shaw
- Veterinary Epidemiology Group, Centre for Tropical and Veterinary Medicine, College of Medicine and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, United Kingdom.
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16
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Haque A, Bowe F, Fitzhenry RJ, Frankel G, Thomson M, Heuschkel R, Murch S, Stevens MP, Wallis TS, Phillips AD, Dougan G. Early interactions of Salmonella enterica serovar typhimurium with human small intestinal epithelial explants. Gut 2004; 53:1424-30. [PMID: 15361488 PMCID: PMC1774215 DOI: 10.1136/gut.2003.037382] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Salmonella enterica serovar typhimurium (S typhimurium) causes invasive gastroenteritis in humans, a disease involving significant penetration of the intestinal mucosa. However, few studies have been undertaken to investigate this interaction directly using differentiated human gut tissue. AIMS To investigate the early interactions of an enteropathogenic strain of S typhimurium with human intestinal mucosa using human intestinal in vitro organ culture (IVOC). METHODS Wild-type and mutant derivatives of S typhimurium TML were used to compare interactions with cultured human epithelial cells, bovine ligated loops, and human intestinal IVOC. RESULTS S typhimurium TML was shown to attach to cultured Caco-2 brush border expressing cells and cause tissue damage and fluid accumulation in a ligated bovine loop model.S typhimurium TML bound predominantly to the mucus layer of human IVOC explants during the first four hours of IVOC incubation. From four to eight hours of IVOC incubation, small but characteristic foci of attaching and invading S typhimurium TML were detected as clusters of bacteria interacting with enterocytes, although there was no evidence for large scale invasion of explant tissues. Ruffling of enterocyte membranes associated with adherent Salmonella was visualised using electron microscopy. CONCLUSIONS Human IVOC can be used as an alternative model for monitoring the interactions between S typhimurium and human intestinal epithelium, thus potentially offering insight into the early stages of human Salmonella induced gastroenteritis.
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Affiliation(s)
- A Haque
- Immunology Unit, Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel St, London WC1E 7HT, UK.
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17
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Jenkins C, Pearce MC, Smith AW, Knight HI, Shaw DJ, Cheasty T, Foster G, Gunn GJ, Dougan G, Smith HR, Frankel G. Detection of Escherichia coli serogroups O26, O103, O111 and O145 from bovine faeces using immunomagnetic separation and PCR/DNA probe techniques. Lett Appl Microbiol 2003; 37:207-12. [PMID: 12904221 DOI: 10.1046/j.1472-765x.2003.01379.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
AIMS The aim of this study was to isolate Escherichia coli O26, O103, O111 and O145 from 745 samples of bovine faeces using (i) immunomagnetic separation (IMS) beads coated with antibodies to lipopolysaccharide, and slide agglutination (SA) tests and (ii) PCR and DNA probes for the detection of the Verocytotoxin (VT) genes. METHODS AND RESULTS IMS-SA tests detected 132 isolates of presumptive E. coli O26, 112 (85%) were confirmed as serogroup O26 and 102 had the VT genes. One hundred and twenty-two strains of presumptive E. coli O103 were isolated by IMS-SA, 45 (37%) were confirmed as serogroup O103 but only one of these strains was identified as Verocytotoxin-producing E. coli (VTEC). Using the PCR/DNA probe method, 40 strains of VTEC O26 and three strains of VTEC O103 were isolated. IMS-SA identified 21 strains of presumptive E. coli O145, of which only four (19%) were confirmed as serogroup O145. VTEC of this serogroup was not detected by either IMS-SA or PCR/DNA probes. E. coli O111 was not isolated by either method. CONCLUSION IMS beads were 2.5 times more sensitive than PCR/DNA probe methods for the detection of VTEC O26 in bovine faeces. SIGNIFICANCE AND IMPACT OF THE STUDY IMS-SA is a sensitive method for detecting specific E. coli serogroups. However, the specificity of this method would be enhanced by the introduction of selective media and the use of tube agglutination tests for confirmation of the preliminary SA results.
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Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK.
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18
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Jenkins C, Willshaw GA, Evans J, Cheasty T, Chart H, Shaw DJ, Dougan G, Frankel G, Smith HR. Subtyping of virulence genes in verocytotoxin-producing Escherichia coli (VTEC) other than serogroup O157 associated with disease in the United Kingdom. J Med Microbiol 2003; 52:941-947. [PMID: 14532337 DOI: 10.1099/jmm.0.05160-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Verocytotoxin-producing Escherichia coli (VTEC) causes a wide spectrum of disease in humans, from mild diarrhoea to haemolytic uraemic syndrome (HUS). The verocytotoxin (vtx) and intimin (eae) genes of VTEC strains, other than those of serogroup O157, were subtyped to identify common properties that may be associated with increased pathogenicity. Strains were isolated from patients with HUS, those with diarrhoea or from asymptomatic individuals. Strains of VTEC that carried vtx(2) gene subtypes vtx(2) and vtx(2c) were most commonly associated with HUS, whereas strains from patients with less severe disease and from the healthy control group were more likely to have vtx(1c) or vtx(2d) genes. The eae gene was detected more frequently in strains isolated from HUS patients than in those associated with cases of diarrhoea; beta-intimin was the most common intimin subtype in strains isolated from both groups of patients. None of the strains from the healthy control group carried the eae gene.
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Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - G A Willshaw
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - J Evans
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - T Cheasty
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - H Chart
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - D J Shaw
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - G Dougan
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - G Frankel
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
| | - H R Smith
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, London, NW9 5HT, UK 2Scottish Agricultural College, Veterinary Science Division, Drummondhill, Stratherrick Rd, Inverness, IV2 4JZ, UK 3Centre for Tropical and Veterinary Medicine, University of Edinburgh, Roslin, Midlothian, EH25 9RG, UK 4Centre for Molecular Microbiology and Immunology, Flowers Building, Imperial College, London, SW7 2AZ, UK
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Jenkins C, Lawson AJ, Cheasty T, Willshaw GA, Wright P, Dougan G, Frankel G, Smith HR. Subtyping intimin genes from enteropathogenic Escherichia coli associated with outbreaks and sporadic cases in the United Kingdom and Eire. Mol Cell Probes 2003; 17:149-56. [PMID: 12944116 DOI: 10.1016/s0890-8508(03)00046-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PCR-RFLP methods for subtyping the intimin gene from strains of typical and atypical enteropathogenic Escherichia coli (EPEC) and Verocytotoxin-producing E. coli (VTEC) were compared. A novel HhaI PCR-RFLP method was developed that was rapid, easy to use and amplified an 1852 bp fragment of the intimin gene from all isolates examined. This method was used to investigate the intimin sub-types of EPEC strains associated with 14 outbreaks of diarrhoeal disease between 1967 and 2001, and 20 sporadic cases between January and December 2000, in the UK and Eire. In this study, genes encoding alpha, beta, gamma, delta and zeta-intimin were detected in the EPEC strains associated with outbreaks and beta, gamma, epsilon, theta and zeta-intimin genes were identified in isolates from sporadic cases. The beta-intimin gene was the most frequently detected sub-type in both the outbreak and sporadic strains.
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Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, Specialist and Reference Microbiology Division, Health Protection Agency, 61 Colindale Avenue, NW9 5HT, London, UK.
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20
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Jenkins C, Pearce MC, Chart H, Cheasty T, Willshaw GA, Gunn GJ, Dougan G, Smith HR, Synge BA, Frankel G. An eight-month study of a population of verocytotoxigenic Escherichia coli (VTEC) in a Scottish cattle herd. J Appl Microbiol 2003; 93:944-53. [PMID: 12452950 DOI: 10.1046/j.1365-2672.2002.01771.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Strains of Verocytotoxin-producing Escherichia coli (VTEC) from Scottish beef cattle on the same farm were isolated during four visits over a period of eight months. Characteristics of these strains were examined to allow comparisons with strains of VTEC associated with human infection. METHODS AND RESULTS Strains were characterized to investigate the relationship between these bovine isolates with respect to serotype, Verocytotoxin (VT) type, intimin-type, and presence or absence of the enterohaemolysin genes. VT genes were detected in 176 of 710 (25%) faecal samples tested using PCR, although only 94 (13%) VTEC strains were isolated using DNA probes on cultures. Forty-five different serotypes were detected. Commonly isolated serotypes included O128ab:H8, O26:H11 and O113:H21. VTEC O26:H11 and O113:H21 have been associated with human disease. Strains harbouring the VT2 genes were most frequently isolated during the first three visits to the farm and those with both VT1 and VT2 genes were the major type during the final visit. Of the 94 strains of non-O157 VTEC isolated, 16 (17%) had the intimin gene; nine had the gene encoding beta-intimin and seven strains had an eta/zeta-intimin gene. Forty-one (44%) of 94 strains carried enterohaemolysin genes. CONCLUSIONS Different serotypes and certain transmissible characteristics, such as VT-type and the enterohaemolysin phenotype, appeared to be common throughout the VTEC population at different times. SIGNIFICANCE AND IMPACT OF THE STUDY Detailed typing and subtyping strains of VTEC as described in this study may improve our understanding of the relationship between bovine VTEC and those found in the human population.
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Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, UK
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21
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Atkins T, Prior RG, Mack K, Russell P, Nelson M, Oyston PCF, Dougan G, Titball RW. A mutant of Burkholderia pseudomallei, auxotrophic in the branched chain amino acid biosynthetic pathway, is attenuated and protective in a murine model of melioidosis. Infect Immun 2002; 70:5290-4. [PMID: 12183585 PMCID: PMC128252 DOI: 10.1128/iai.70.9.5290-5294.2002] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Using a transposon mutagenesis approach, we have identified a mutant of Burkholderia pseudomallei that is auxotrophic for branched chain amino acids. The transposon was shown to have interrupted the ilvI gene encoding the large subunit of the acetolactate synthase enzyme. Compared to the wild type, this mutant was significantly attenuated in a murine model of disease. Mice inoculated intraperitoneally with the auxotrophic mutant, 35 days prior to challenge, were protected against a challenge dose of 6,000 median lethal doses of wild-type B. pseudomallei.
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Affiliation(s)
- T Atkins
- Defence Science and Technology Laboratory, Salisbury, Wiltshire SP4 OJQ, United Kingdom.
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22
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Jenkins C, Chart H, Cheasty T, Willshaw GA, Pearce MC, Foster G, Gunn GJ, Smith HR, Dougan G, Synge BA, Frankel G. Verocytotoxin-producing Escherichia coli (VTEC) other than serogroup O157 from Scottish cattle. Vet Rec 2002; 151:58-60. [PMID: 12148605 DOI: 10.1136/vr.151.2.58] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Central Public Health Authority, London
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23
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Fitzhenry RJ, Pickard DJ, Hartland EL, Reece S, Dougan G, Phillips AD, Frankel G. Intimin type influences the site of human intestinal mucosal colonisation by enterohaemorrhagic Escherichia coli O157:H7. Gut 2002; 50:180-5. [PMID: 11788556 PMCID: PMC1773112 DOI: 10.1136/gut.50.2.180] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND Enterohaemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli epithelial cell adhesion is characterised by intimate attachment, and attaching and effacing (A/E) lesion formation. This event is mediated in part by intimin binding to another bacterial protein, Tir (translocated intimin receptor), which is exported by the bacteria and integrated into the host cell plasma membrane. Importantly, EPEC (O127:H6) and EHEC (O157:H7) express antigenically distinct intimin types known as intimin alpha and gamma, respectively. EHEC (O157:H7) colonises human intestinal explants although adhesion is restricted to the follicle associated epithelium of Peyer's patches. This phenotype is also observed with EPEC O127:H6 engineered to express EHEC intimin gamma. AIMS To investigate the influence of intimin on colonisation of human intestine by E coli O157:H7, and intimin types on tissue tropism in humans. METHODS Human intestinal in vitro organ culture with wild type and mutant strains of O157:H7 were employed. RESULTS Introducing a deletion mutation in the eae gene encoding intimin gamma in EHEC (O157:H7) caused the strain (ICC170) to fail to colonise human intestinal explants. However, colonisation of Peyer's patches and A/E lesion formation were restored with intimin gamma expression from a plasmid (ICC170 (pICC55)). In contrast, complementing the mutation with intimin alpha resulted in a strain (ICC170 (pCVD438)) capable of colonising and producing A/E lesions on both Peyer's patch and other small intestinal explants. CONCLUSION Intimin is necessary for human intestinal mucosal colonisation by E coli O157:H7. Intimin type influences the site of colonisation in a Tir type independent mechanism; intimin gamma appears to restrict colonisation to human follicle associated epithelium.
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Affiliation(s)
- R J Fitzhenry
- Centre for Paediatric Gastroenterology, Department of Paediatrics and Child Health, Royal Free Hospital, London, UK
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24
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Abstract
Intramuscular (i.m.) immunisation of BALB/c mice with a DNA vaccine, pcDNA3/tetC, encoding fragment C (TetC) from tetanus toxin, stimulated production of TetC specific IgG2a antibodies in the serum and release of IFN-gamma from TetC stimulated splenocytes. A similar pattern of immune response was detected if pcDNA3/tetC primed mice were boosted i.m. with purified TetC protein or TetC and cholera toxin (included as an adjuvant). In contrast, control mice primed with the empty DNA vector pcDNA3 and boosted i.m. with TetC or TetC and CT, generated a dominant IgG1 specific anti-TetC response in the sera and low or undetectable levels of IFN-gamma from stimulated splenocytes. Thus, i.m. priming with a DNA vaccine modulated the subsequent immune response to the same antigen administered as a protein boost. Similar observations were made when DNA primed mice were boosted using the intranasal mucosal route of immunisation. Interestingly, although mice immunised with pcDNA3/tetC and boosted mucosally with TetC and CT produced anti-TetC IgA in mucosal secretions, the titres were reproducibly lower than those detected in mice immunised with the pcDNA3 vector alone. The immunomodulatory effect of pcDNA3/tetC appeared to be antigen specific as mucosal boosting with an unrelated antigen (pertactin) revealed no significant modulation in terms of the anti-pertactin immune response.
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Affiliation(s)
- R Stratford
- Centre for Molecular Microbiology and Infection, Department of Biochemistry and Biology, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, UK
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25
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Gonçalves NS, Ghaem-Maghami M, Monteleone G, Frankel G, Dougan G, Lewis DJ, Simmons CP, MacDonald TT. Critical role for tumor necrosis factor alpha in controlling the number of lumenal pathogenic bacteria and immunopathology in infectious colitis. Infect Immun 2001; 69:6651-9. [PMID: 11598034 PMCID: PMC100039 DOI: 10.1128/iai.69.11.6651-6659.2001] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2001] [Accepted: 08/10/2001] [Indexed: 11/20/2022] Open
Abstract
Infection of mice with the intestinal bacterial pathogen Citrobacter rodentium results in colonic mucosal hyperplasia and a local Th1 inflammatory response similar to that seen in mouse models of inflammatory bowel disease. In these latter models, and in patients with Crohn's disease, neutralization of tumor necrosis factor alpha (TNF-alpha) is of therapeutic benefit. Since there is no information on the role of TNF-alpha in either immunity to noninvasive bacterial pathogens or on the role of TNF-alpha in the immunopathology of infectious colitis, we investigated C. rodentium infection in TNFRp55(-/-) mice. In TNFRp55(-/-) mice, there were higher colonic bacterial burdens, but the organisms were cleared at the same rate as C57BL/6 mice, showing that TNF-alpha is not needed for protective antibacterial immunity. The most striking feature of infection in TNFRp55(-/-) mice, however, was the markedly enhanced pathology, with increased mucosal weight and thickness, increased T-cell infiltrate, and a markedly greater mucosal Th1 response. Interleukin-12 p40 transcripts were markedly elevated in C. rodentium-infected TNFRp55(-/-) mice, and this was associated with enhanced mucosal STAT4 phosphorylation. TNF-alpha is not obligatory for protective immunity to C. rodentium in mice; however, it appears to play some role in downregulating mucosal pathology and Th1 immune responses.
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MESH Headings
- Animals
- Antigens, CD/genetics
- Antigens, CD/immunology
- CD4-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/immunology
- Citrobacter freundii/growth & development
- Citrobacter freundii/immunology
- Colon/microbiology
- Colon/pathology
- Colonic Diseases, Functional/immunology
- Colonic Diseases, Functional/pathology
- DNA-Binding Proteins/metabolism
- Enterobacteriaceae Infections/immunology
- Enterobacteriaceae Infections/pathology
- Female
- Gene Expression
- Hyperplasia/immunology
- Hyperplasia/pathology
- Interleukin-12/genetics
- Interleukin-4/genetics
- Intestinal Mucosa/immunology
- Intestinal Mucosa/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Receptors, Tumor Necrosis Factor/genetics
- Receptors, Tumor Necrosis Factor/immunology
- Receptors, Tumor Necrosis Factor, Type I
- STAT4 Transcription Factor
- Trans-Activators/metabolism
- Tumor Necrosis Factor-alpha/immunology
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Affiliation(s)
- N S Gonçalves
- School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, United Kingdom
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26
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Parkhill J, Dougan G, James KD, Thomson NR, Pickard D, Wain J, Churcher C, Mungall KL, Bentley SD, Holden MT, Sebaihia M, Baker S, Basham D, Brooks K, Chillingworth T, Connerton P, Cronin A, Davis P, Davies RM, Dowd L, White N, Farrar J, Feltwell T, Hamlin N, Haque A, Hien TT, Holroyd S, Jagels K, Krogh A, Larsen TS, Leather S, Moule S, O'Gaora P, Parry C, Quail M, Rutherford K, Simmonds M, Skelton J, Stevens K, Whitehead S, Barrell BG. Complete genome sequence of a multiple drug resistant Salmonella enterica serovar Typhi CT18. Nature 2001; 413:848-52. [PMID: 11677608 DOI: 10.1038/35101607] [Citation(s) in RCA: 883] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Salmonella enterica serovar Typhi (S. typhi) is the aetiological agent of typhoid fever, a serious invasive bacterial disease of humans with an annual global burden of approximately 16 million cases, leading to 600,000 fatalities. Many S. enterica serovars actively invade the mucosal surface of the intestine but are normally contained in healthy individuals by the local immune defence mechanisms. However, S. typhi has evolved the ability to spread to the deeper tissues of humans, including liver, spleen and bone marrow. Here we have sequenced the 4,809,037-base pair (bp) genome of a S. typhi (CT18) that is resistant to multiple drugs, revealing the presence of hundreds of insertions and deletions compared with the Escherichia coli genome, ranging in size from single genes to large islands. Notably, the genome sequence identifies over two hundred pseudogenes, several corresponding to genes that are known to contribute to virulence in Salmonella typhimurium. This genetic degradation may contribute to the human-restricted host range for S. typhi. CT18 harbours a 218,150-bp multiple-drug-resistance incH1 plasmid (pHCM1), and a 106,516-bp cryptic plasmid (pHCM2), which shows recent common ancestry with a virulence plasmid of Yersinia pestis.
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Affiliation(s)
- J Parkhill
- The Sanger Centre, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK.
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27
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Parkhill J, Wren BW, Thomson NR, Titball RW, Holden MT, Prentice MB, Sebaihia M, James KD, Churcher C, Mungall KL, Baker S, Basham D, Bentley SD, Brooks K, Cerdeño-Tárraga AM, Chillingworth T, Cronin A, Davies RM, Davis P, Dougan G, Feltwell T, Hamlin N, Holroyd S, Jagels K, Karlyshev AV, Leather S, Moule S, Oyston PC, Quail M, Rutherford K, Simmonds M, Skelton J, Stevens K, Whitehead S, Barrell BG. Genome sequence of Yersinia pestis, the causative agent of plague. Nature 2001; 413:523-7. [PMID: 11586360 DOI: 10.1038/35097083] [Citation(s) in RCA: 856] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Gram-negative bacterium Yersinia pestis is the causative agent of the systemic invasive infectious disease classically referred to as plague, and has been responsible for three human pandemics: the Justinian plague (sixth to eighth centuries), the Black Death (fourteenth to nineteenth centuries) and modern plague (nineteenth century to the present day). The recent identification of strains resistant to multiple drugs and the potential use of Y. pestis as an agent of biological warfare mean that plague still poses a threat to human health. Here we report the complete genome sequence of Y. pestis strain CO92, consisting of a 4.65-megabase (Mb) chromosome and three plasmids of 96.2 kilobases (kb), 70.3 kb and 9.6 kb. The genome is unusually rich in insertion sequences and displays anomalies in GC base-composition bias, indicating frequent intragenomic recombination. Many genes seem to have been acquired from other bacteria and viruses (including adhesins, secretion systems and insecticidal toxins). The genome contains around 150 pseudogenes, many of which are remnants of a redundant enteropathogenic lifestyle. The evidence of ongoing genome fluidity, expansion and decay suggests Y. pestis is a pathogen that has undergone large-scale genetic flux and provides a unique insight into the ways in which new and highly virulent pathogens evolve.
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Affiliation(s)
- J Parkhill
- The Sanger Centre, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK.
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28
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Abstract
Typhoid fever is an infectious disease of global distribution. Although there is a wealth of data on Salmonella typhimurium infection in the mouse and the interaction of this serovar with human cell lines in vitro, there is a relatively small amount of data on S. typhi and the pathogenesis of typhoid fever. In this review we focus on three areas: adherence to and invasion of gut epithelial cells, dissemination to systemic sites, and survival and replication within host cells. In addition, we attempt to put current salmonella research into the context of typhoid fever.
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Affiliation(s)
- D House
- Centre for Molecular Microbiology and Infection, Imperial College of Science Technology and Medicine, London, UK
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29
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Ghaem-Maghami M, Simmons CP, Daniell S, Pizza M, Lewis D, Frankel G, Dougan G. Intimin-specific immune responses prevent bacterial colonization by the attaching-effacing pathogen Citrobacter rodentium. Infect Immun 2001; 69:5597-605. [PMID: 11500434 PMCID: PMC98674 DOI: 10.1128/iai.69.9.5597-5605.2001] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The formation of attaching and effacing (A/E) lesions on gut enterocytes is central to the pathogenesis of enterohemorrhagic (EHEC) Escherichia coli, enteropathogenic E. coli (EPEC), and the rodent pathogen Citrobacter rodentium. Genes encoding A/E lesion formation map to a chromosomal pathogenicity island termed the locus of enterocyte effacement (LEE). Here we show that the LEE-encoded proteins EspA, EspB, Tir, and intimin are the targets of long-lived humoral immune responses in C. rodentium-infected mice. Mice infected with C. rodentium developed robust acquired immunity and were resistant to reinfection with wild-type C. rodentium or a C. rodentium derivative, DBS255(pCVD438), which expressed intimin derived from EPEC strain E2348/69. The receptor-binding domain of intimin polypeptides is located within the carboxy-terminal 280 amino acids (Int280). Mucosal and systemic vaccination regimens using enterotoxin-based adjuvants were employed to elicit immune responses to recombinant Int280alpha from EPEC strain E2348/69. Mice vaccinated subcutaneously with Int280alpha, in the absence of adjuvant, were significantly more resistant to oral challenge with DBS255(pCVD438) but not with wild-type C. rodentium. This type-specific immunity could not be overcome by employing an exposed, highly conserved domain of intimin (Int388-667) as a vaccine. These results show that anti-intimin immune responses can modulate the outcome of a C. rodentium infection and support the use of intimin as a component of a type-specific EPEC or EHEC vaccine.
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Affiliation(s)
- M Ghaem-Maghami
- Centre for Molecular Microbiology and Infection, Department of Biochemistry, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AZ, United Kingdom
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30
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Wain J, House D, Pickard D, Dougan G, Frankel G. Acquisition of virulence-associated factors by the enteric pathogens Escherichia coli and Salmonella enterica. Philos Trans R Soc Lond B Biol Sci 2001; 356:1027-34. [PMID: 11516380 PMCID: PMC1088497 DOI: 10.1098/rstb.2001.0891] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
In this review we summarize recent genomic studies that shed light on the mechanism through which pathogenic Escherichia coli and Salmonella enterica have evolved. We show how acquisition of DNA at specific sites on the chromosome has contributed to increased genetic variation and virulence of these two genera of the Enterobacteriaceae.
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Affiliation(s)
- J Wain
- Centre for Molecular Microbiology and Infection, Imperial College of Science, Technology and Medicine, South Kensington, London W7 2AZ, UK.
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31
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Abstract
Salmonella typhi continues to cause severe disease in many parts of the world, its most feared complication being perforation of ulcerated Peyer's patches within the small intestine, leading to peritonitis with associated mortality. The pathogenesis of this process is not well understood. In this article, we present a theoretical mechanism as to how bacterial factors and host immunological mediators within infected tissue might contribute to the observed intestinal pathology, and propose that necrosis of the Peyer's patches observed in typhoid is caused by a mechanism similar to the Shwartzman and Koch reactions.
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Affiliation(s)
- P Everest
- Dept of Veterinary Pathology, University of Glasgow Veterinary School, Bearsden Road, G61 1QH, Glasgow, UK.
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32
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Macpherson AJ, Lamarre A, McCoy K, Harriman GR, Odermatt B, Dougan G, Hengartner H, Zinkernagel RM. IgA production without mu or delta chain expression in developing B cells. Nat Immunol 2001; 2:625-31. [PMID: 11429547 DOI: 10.1038/89775] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Surface, membrane-bound, immunoglobulin M (IgM) or IgD expression early in B cell ontogeny is considered essential for the differentiation of antibody-producing cells in mammals; only in IgM+ B cells is the heavy chain locus rearranged to express antibodies of other classes. We show here that IgA is selectively expressed in muMT mice, which lack IgM or IgD expression and have a pro-B cell developmental block. muMT IgA binds proteins of commensal intestinal bacteria and is weakly induced by Salmonella infection, although not through conventional immunization. This muMT IgA pathway requires extrasplenic peripheral lymphoid tissues and may be an evolutionarily primitive system in which immature B cells switch to IgA production at peripheral sites.
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Affiliation(s)
- A J Macpherson
- Institute of Experimental Immunology, Universitätsspital, Schmelzbergstrasse 12, CH8091 Zürich, Switzerland.
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33
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Abstract
Mucosal immune responses must discriminate between commensal flora within the lumen and potential pathogens. These responses are highly adapted to induce protection without excessive inflammation. The balances that regulate mucosal immune and inflammatory responses have to be understood if effective mucosal immunity is to be induced through local immunization. This review will summarize some of the lessons learnt from studies of antigens derived from enteric bacterial pathogens and discuss how the gastrointestinal epithelia can 'fight back' when it encounters pathogens.
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Affiliation(s)
- C P Simmons
- Centre for Molecular Microbiology and Infection, Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK
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34
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Calabi E, Ward S, Wren B, Paxton T, Panico M, Morris H, Dell A, Dougan G, Fairweather N. Molecular characterization of the surface layer proteins from Clostridium difficile. Mol Microbiol 2001; 40:1187-99. [PMID: 11401722 DOI: 10.1046/j.1365-2958.2001.02461.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Many bacteria express a surface-exposed proteinaceous layer, termed the S-layer, which forms a regular two-dimensional array visible by electron microscopy. Clostridium difficile is unusual in expressing two S-layer proteins (SLPs), which are of varying size in a number of strains. In an approach combining molecular biology with mass spectrometric sequencing strategies, we have identified the structural gene (slpA) for the S-layer from three strains of C. difficile. Both proteins are derived from a common precursor, and processing involves the removal of a signal peptide and a second cleavage to release the two mature SLPs. To our knowledge, this is the first example in which two SLPs have been shown to derive from a single gene product through post-translational processing, rather than from the expression of separate genes. The higher molecular weight (MW) SLP is highly conserved among the three strains, whereas the lower MW SLP shows considerable sequence diversity, reflecting the results from Western blotting. The high-MW SLP shows weak homology to N-acetyl muramoyl-L-alanine amidase from Bacillus subtilis, and both the native SLP from C. difficile and a recombinant protein expressed in Escherichia coli were found to display amidase activity by zymography. The high-MW SLPs showed evidence of glycosylation, whereas the lower MW proteins did not. A family of genes with sequence homology to the amidase domain of the high-MW SLP was identified in the C. difficile strain 630 genome, some of which are located in the same region of the genome as slpA and were shown by reverse transcription-polymerase chain reaction (RT-PCR) analysis to be transcribed.
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Affiliation(s)
- E Calabi
- Department of Biology and Biochemistry, Imperial College, South Kensington, London SW7 2AY, UK
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35
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Chiesa MD, Martensen PM, Simmons C, Porakishvili N, Justesen J, Dougan G, Roitt IM, Delves PJ, Lund T. Refocusing of B-cell responses following a single amino acid substitution in an antigen. Immunology 2001; 103:172-8. [PMID: 11412304 PMCID: PMC1783232 DOI: 10.1046/j.1365-2567.2001.01242.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Intranasal immunization of BALB/c strain mice was carried out using baculovirus-derived human chorionic gonadotrophin (hCG) beta-chain, together with Escherichia coli heat-labile enterotoxin. Gonadotrophin-reactive immunoglobulin A (IgA) was induced in a remote mucosal site, the lung, in addition to a systemic IgG response. The extensive sequence homology with luteinizing hormone (LH) results in the production of LH cross-reactive antibodies when holo-hCG is used as an immunogen. In contrast to wild-type hCGbeta, a mutated hCGbeta-chain containing an arginine to glutamic acid substitution at position 68 did not induce the production of antibodies which cross-react with LH. Furthermore, the epitopes utilized in the B-cell response to the mutated hCGbeta shifted away from the immunodominant region of the parent wild-type molecule towards epitopes within the normally weakly immunogenic C terminus. This shift in epitope usage was also seen following intramuscular immunization of rabbits. Thus, a single amino acid change, which does not disrupt the overall structure of the molecule, refocuses the immune response away from a disadvantageous cross-reactive epitope region and towards a normally weakly immunogenic but antigen-unique area. Similar mutational strategies for epitope-refocusing may be applicable to other vaccine candidate molecules.
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MESH Headings
- Administration, Intranasal
- Animals
- Antigens/chemistry
- Antigens/immunology
- B-Lymphocytes/immunology
- Baculoviridae/genetics
- Chorionic Gonadotropin, beta Subunit, Human/chemistry
- Chorionic Gonadotropin, beta Subunit, Human/genetics
- Chorionic Gonadotropin, beta Subunit, Human/immunology
- Cross Reactions
- Epitopes, B-Lymphocyte/immunology
- Female
- Immunity, Mucosal
- Immunization/methods
- Immunoglobulin A, Secretory/biosynthesis
- Immunoglobulin G/biosynthesis
- Lung/immunology
- Mice
- Mice, Inbred BALB C
- Plasmids
- Point Mutation
- Rabbits
- Recombinant Proteins/immunology
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Affiliation(s)
- M D Chiesa
- Department of Immunology and Molecular Pathology, The Windeyer Institute for Medical Sciences, University College London, UK
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36
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Townsend SM, Kramer NE, Edwards R, Baker S, Hamlin N, Simmonds M, Stevens K, Maloy S, Parkhill J, Dougan G, Bäumler AJ. Salmonella enterica serovar Typhi possesses a unique repertoire of fimbrial gene sequences. Infect Immun 2001; 69:2894-901. [PMID: 11292704 PMCID: PMC98240 DOI: 10.1128/iai.69.5.2894-2901.2001] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2000] [Accepted: 01/29/2001] [Indexed: 12/21/2022] Open
Abstract
Salmonella enterica serotype Typhi differs from nontyphoidal Salmonella serotypes by its strict host adaptation to humans and higher primates. Since fimbriae have been implicated in host adaptation, we investigated whether the serotype Typhi genome contains fimbrial operons which are unique to this pathogen or restricted to typhoidal Salmonella serotypes. This study established for the first time the total number of fimbrial operons present in an individual Salmonella serotype. The serotype Typhi CT18 genome, which has been sequenced by the Typhi Sequencing Group at the Sanger Centre, contained a type IV fimbrial operon, an orthologue of the agf operon, and 12 putative fimbrial operons of the chaperone-usher assembly class. In addition to sef, fim, saf, and tcf, which had been described previously in serotype Typhi, we identified eight new putative chaperone-usher-dependent fimbrial operons, which were termed bcf, sta, stb, ste, std, stc, stg, and sth. Hybridization analysis performed with 16 strains of Salmonella reference collection C and 22 strains of Salmonella reference collection B showed that all eight putative fimbrial operons of serotype Typhi were also present in a number of nontyphoidal Salmonella serotypes. Thus, a simple correlation between host range and the presence of a single fimbrial operon seems at present unlikely. However, the serotype Typhi genome differed from that of all other Salmonella serotypes investigated in that it contained a unique combination of putative fimbrial operons.
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Affiliation(s)
- S M Townsend
- Department of Medical Microbiology and Immunology, College of Medicine, Texas A&M University, College Station, Texas 77843, USA
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37
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Abstract
Intimate bacterial adhesion to the intestinal epithelium is a pathogenic mechanism shared by several human and animal enteric pathogens, including enteropathogenic and enterohaemorrhagic Escherichia coli. Two bacterial protein partners involved in this intimate association have been identified, intimin and Tir. Some key remaining questions include whether intimin specifically interacts with one or more host-cell-encoded molecules and whether these contacts are a prerequisite for the subsequent intimate intimin-Tir association. Recent data support the hypothesis that the formation of a stable intimin-Tir relationship is the consequence of intimin protein interactions involving both host and bacterial components.
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Affiliation(s)
- G Frankel
- Centre for Molecular Microbiology and Infection, Dept. of Biochemistry, Imperial College of Science, Technology and Medicine, SW7 2AZ, London, UK.
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38
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Prentice MB, James KD, Parkhill J, Baker SG, Stevens K, Simmonds MN, Mungall KL, Churcher C, Oyston PC, Titball RW, Wren BW, Wain J, Pickard D, Hien TT, Farrar JJ, Dougan G. Yersinia pestis pFra shows biovar-specific differences and recent common ancestry with a Salmonella enterica serovar Typhi plasmid. J Bacteriol 2001; 183:2586-94. [PMID: 11274119 PMCID: PMC95176 DOI: 10.1128/jb.183.8.2586-2594.2001] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Population genetic studies suggest that Yersinia pestis, the cause of plague, is a clonal pathogen that has recently emerged from Yersinia pseudotuberculosis. Plasmid acquisition is likely to have been a key element in this evolutionary leap from an enteric to a flea-transmitted systemic pathogen. However, the origin of Y. pestis-specific plasmids remains obscure. We demonstrate specific plasmid rearrangements in different Y. pestis strains which distinguish Y. pestis bv. Orientalis strains from other biovars. We also present evidence for plasmid-associated DNA exchange between Y. pestis and the exclusively human pathogen Salmonella enterica serovar Typhi.
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Affiliation(s)
- M B Prentice
- Department of Medical Microbiology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, London, United Kingdom.
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39
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Dunstan SJ, Ho VA, Duc CM, Lanh MN, Phuong CX, Luxemburger C, Wain J, Dudbridge F, Peacock CS, House D, Parry C, Hien TT, Dougan G, Farrar J, Blackwell JM. Typhoid fever and genetic polymorphisms at the natural resistance-associated macrophage protein 1. J Infect Dis 2001; 183:1156-60. [PMID: 11237848 PMCID: PMC2413323 DOI: 10.1086/319289] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2000] [Revised: 12/21/2000] [Indexed: 11/04/2022] Open
Abstract
Control of Salmonella enterica serovar Typhimurium (S. typhimurium) infection in the mouse model of typhoid fever is critically dependent on the natural resistance-associated macrophage protein 1 (Nramp1). In this study, we examined the role of genetic polymorphisms in the human homologue, NRAMP1, in resistance to typhoid fever in southern Vietnam. Patients with blood-culture-confirmed typhoid fever and healthy control subjects were genotyped for 6 polymorphic markers within and near NRAMP1 on chromosome 2q35. Four single base-pair polymorphisms (274 C/T, 469+14 G/C, 1465-85 G/A, and D543N), a (GT)(n) repeat in the promoter region of NRAMP1 and D2S1471, and a microsatellite marker approximately 130-kb downstream of NRAMP1 were examined. The allelic and genotypic frequencies for each polymorphism were compared in case patients and control subjects. No allelic association was identified between the NRAMP1 alleles and typhoid fever susceptibility. In addition, neither homozygotes nor heterozygotes for any NRAMP1 variants were at increased risk of typhoid fever.
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Affiliation(s)
- S J Dunstan
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom.
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40
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Reece S, Simmons CP, Fitzhenry RJ, Matthews S, Phillips AD, Dougan G, Frankel G. Site-directed mutagenesis of intimin alpha modulates intimin-mediated tissue tropism and host specificity. Mol Microbiol 2001; 40:86-98. [PMID: 11298278 DOI: 10.1046/j.1365-2958.2001.02371.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The hallmark of enteropathogenic (EPEC) and enterohaemorrhagic (EHEC) Escherchia coli adhesion to host cells is intimate attachment leading to the formation of distinctive 'attaching and effacing' lesions. This event is mediated, in part, by binding of the bacterial adhesion molecule intimin to a second bacterial protein, Tir, delivered by a type III secretion system into the host cell plasma membrane. The receptor-binding activity of intimin is localized to the C-terminal 280 amino acids (Int280) and at least five distinct intimin types (alpha, beta, gamma, delta and epsilon) have been identified thus far. In addition to binding to Tir, intimin can also bind to a component encoded by the host. The consequence of latter intimin-binding activity may determine tissue tropism and host specificity. In this study we selected three amino acids in intimin, which are implicated in Tir binding, for site-directed mutagenesis. We used the yeast two-hybrid system and gel overlays to study intimin-Tir protein interaction. In addition, the biological consequences of the mutagenesis was tested using a number of infection models (cultured epithelial cells, human intestinal explants and a mouse model). We report that while an I237/897A substitution (positions numbered according to Int280alpha/whole intimin alpha) in intimin alpha did not have any affect on its biological activity, a T255/914A substitution attenuated intimin activity in vivo. In contrast, the mutation V252/911A affected tissue targeting in the human intestinal explant model and attenuated the biological activity of intimin in the mouse model. This study provides the first clues of the molecular basis of how intimin mediates tissue tropism and host specificity.
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Affiliation(s)
- S Reece
- Centre for Molecular Microbiology and Infection, Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK
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41
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Pizza M, Giuliani MM, Fontana MR, Monaci E, Douce G, Dougan G, Mills KH, Rappuoli R, Del Giudice G. Mucosal vaccines: non toxic derivatives of LT and CT as mucosal adjuvants. Vaccine 2001; 19:2534-41. [PMID: 11257389 DOI: 10.1016/s0264-410x(00)00553-3] [Citation(s) in RCA: 240] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Most vaccines are still delivered by injection. Mucosal vaccination would increase compliance and decrease the risk of spread of infectious diseases due to contaminated syringes. However, most vaccines are unable to induce immune responses when administered mucosally, and require the use of strong adjuvant on effective delivery systems. Cholera toxin (CT) and Escherichia coli enterotoxin (LT) are powerful mucosal adjuvants when co-administered with soluble antigens. However, their use in humans is hampered by their extremely high toxicity. During the past few years, site-directed mutagenesis has permitted the generation of LT and CT mutants fully non toxic or with dramatically reduced toxicity, which still retain their strong adjuvanticity at the mucosal level. Among these mutants, are LTK63 (serine-to-lysine substitution at position 63 in the A subunit) and LTR72 (alanine-to-arginine substitution at position 72 in the A subunit). The first is fully non toxic, whereas the latter retains some residual enzymatic activity. Both of them are extremely active as mucosal adjuvants, being able to induce very high titers of antibodies specific for the antigen with which they are co-administered. Both mutants have now been tested as mucosal adjuvants in different animal species using a wide variety of antigens. Interestingly, mucosal delivery (nasal or oral) of antigens together with LTK63 or LTR72 mutants also conferred protection against challenge in appropriate animal models (e.g. tetanus, Helicobacter pylori, pertussis, pneumococci, influenza, etc). In conclusion, these LTK63 and LTR72 mutants are safe adjuvants to enhance the immunogenicity of vaccines at the mucosal level, and will be tested soon in humans.
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Affiliation(s)
- M Pizza
- IRIS, Chiron S.p.A., Via Fiorentina 1, 53100, Siena, Italy.
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42
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Abstract
Immunologic unresponsiveness (tolerance) is a key feature of the mucosal immune system, and deliberate vaccination by a mucosal route can effectively induce immune suppression. However, some bacterial-derived proteins, e.g. cholera toxin and the heat labile toxin of Escherichia coli, are immunogenic and immunomodulatory at mucosal surfaces and can effectively adjuvant immune responses to codelivered bystander antigens. This review summarizes some of the structural and biological characteristics of these toxins and provides examples of how these properties have been exploited for tolerance induction and mucosal vaccine development.
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Affiliation(s)
- C P Simmons
- Department of Biochemistry, Imperial College of Science Technology and Medicine, South Kensington, London SW7 2AZ, UK.
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43
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House D, Wain J, Ho VA, Diep TS, Chinh NT, Bay PV, Vinh H, Duc M, Parry CM, Dougan G, White NJ, Hien TT, Farrar JJ. Serology of typhoid fever in an area of endemicity and its relevance to diagnosis. J Clin Microbiol 2001; 39:1002-7. [PMID: 11230418 PMCID: PMC87864 DOI: 10.1128/jcm.39.3.1002-1007.2001] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Currently, the laboratory diagnosis of typhoid fever is dependent upon either the isolation of Salmonella enterica subsp. enterica serotype Typhi from a clinical sample or the detection of raised titers of agglutinating serum antibodies against the lipopolysaccharide (LPS) (O) or flagellum (H) antigens of serotype Typhi (the Widal test). In this study, the serum antibody responses to the LPS and flagellum antigens of serotype Typhi were investigated with individuals from a region of Vietnam in which typhoid is endemic, and their usefulness for the diagnosis of typhoid fever was evaluated. The antibody responses to both antigens were highly variable among individuals infected with serotype Typhi, and elevated antibody titers were also detected in a high proportion of serum samples from healthy subjects from the community. In-house enzyme-linked immunosorbent assays (ELISAs) for the detection of specific classes of anti-LPS and antiflagellum antibodies were compared with other serologically based tests for the diagnosis of typhoid fever (Widal TO and TH, anti-serotype Typhi immunoglobulin M [IgM] dipstick, and IDeaL TUBEX). At a specificity of > or =0.93, the sensitivities of the different tests were 0.75, 0.55, and 0.52 for the anti-LPS IgM, IgG, and IgA ELISAs, respectively; 0.28 for the antiflagellum IgG ELISA; 0.47 and 0.32 for the Widal TO and TH tests, respectively; and 0.77 for the anti-serotype Typhi IgM dipstick assay. The specificity of the IDeaL TUBEX was below 0.90 (sensitivity, 0.87; specificity, 0.76). The serological assays based on the detection of IgM antibodies against either serotype Typhi LPS (ELISA) or whole bacteria (dipstick) had a significantly higher sensitivity than the Widal TO test when used with a single acute-phase serum sample (P < or = 0.007). These tests could be of use for the diagnosis of typhoid fever in patients who have clinical typhoid fever but are culture negative or in regions where bacterial culturing facilities are not available.
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Affiliation(s)
- D House
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, South Kensington, London SW7 2AZ, United Kingdom.
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Abstract
Salmonella infections are a serious medical and veterinary problem world-wide and cause concern in the food industry. Vaccination is an effective tool for the prevention of Salmonella infections. Host resistance to Salmonella relies initially on the production of inflammatory cytokines leading to the infiltration of activated inflammatory cells in the tissues. Thereafter T- and B-cell dependent specific immunity develops allowing the clearance of Salmonella microorganisms from the tissues and the establishment of long-lasting acquired immunity to re-infection. The increased resistance that develops after primary infection/ vaccination requires T-cells cytokines such as IFNgamma TNFalpha and IL12 in addition to opsonising antibody. However for reasons that are not fully understood seroconversion and/or the presence of detectable T-cell memory do not always correlate with the development of acquired resistance to infection.Whole-cell killed vaccines and subunit vaccines are used in the prevention of Salmonella infection in animals and in humans with variable results. A number of early live Salmonella vaccines derived empirically by chemical or u.v. mutagenesis proved to be immunogenic and protective and are still in use despite the need for repeated parenteral administration. Recent progress in the knowledge of the genetics of Salmonella virulence and modern recombinant DNA technology offers the possibility to introduce multiple defined attenuating and irreversible mutations into the bacterial genome. This has recently allowed the development of Salmonella strains devoid of significant side effects but still capable of inducing solid immunity after single oral administration. Live attenuated Salmonella vaccines have been used for the expression of heterologous antigens/proteins that can be successfully delivered to the immune system. Furthermore Salmonella can transfer plasmids encoding foreign antigens under the control of eukaryotic promoters (DNA vaccines) to antigen-presenting cells resulting in targeted delivery of DNA vaccines to these cells. Despite the great recent advances in the development of Salmonella vaccines a large proportion of the work has been conducted in laboratory rodents and more research in other animal species is required.
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Affiliation(s)
- P Mastroeni
- Centre for Veterinary Science, University of Cambridge, Madingley Road, Cambridge, CB3 OES, UK.
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Abstract
Wild Escherichia coli are superbly adapted to survive in the intestines of their mammalian hosts and in the environment. E. coli K12 derivative (MG1655) encodes 4288 potential genes that provide the background genetic framework of this species. Particular E. coli clonal types encode additional chromosomal and extrachromosomal genes that facilitate the ability of E. coli to adapt to new environments. These additional genes are often clustered, have related functions (for example, virulence-associated genes in pathogenicity islands) and may be integrated at specific sites on the E. coli chromosome.
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Affiliation(s)
- G Dougan
- Centre for Molecular Microbiology and Infection, Department of Biochemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, SW7 2AZ, London, UK.
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Dunstan SJ, Stephens HA, Blackwell JM, Duc CM, Lanh MN, Dudbridge F, Phuong CX, Luxemburger C, Wain J, Ho VA, Hien TT, Farrar J, Dougan G. Genes of the class II and class III major histocompatibility complex are associated with typhoid fever in Vietnam. J Infect Dis 2001; 183:261-268. [PMID: 11120931 DOI: 10.1086/317940] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2000] [Revised: 10/04/2000] [Indexed: 11/03/2022] Open
Abstract
The influence of genes of the major histocompatibility complex (MHC) class II and class III loci on typhoid fever susceptibility was investigated. Individuals with blood culture-confirmed typhoid fever and control subjects from 2 distinct geographic locations in southern Vietnam were genotyped for HLA-DRB1 and HLA-DQB1 alleles, the gene that encodes tumor necrosis factor (TNF)-alpha (TNFA [-238] and TNFA [-308]), the gene that encodes lymphotoxin-alpha, and alleles of the TNF-alpha microsatellite. HLA-DRB1*0301/6/8, HLA-DQB1*0201-3, and TNFA*2 (-308) were associated with susceptibility to typhoid fever, whereas HLA-DRB1*04, HLA-DQB1*0401/2, and TNFA*1 (-308) were associated with disease resistance. The frequency of all possible haplotypes of the 3 individually associated loci were estimated and were found to be significantly different in typhoid case patients and control subjects (chi2=55.56, 32 df; P=.006). Haplotypes that were either protective (TNFA*1 [-308].DRB1*04) or predisposed individuals to typhoid fever (TNFA*2 [-308].DRB1*0301) were determined. This report identifies a genetic association in humans between typhoid fever and MHC class II and III genes.
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Affiliation(s)
- S J Dunstan
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom.
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Simmons CP, Hussell T, Sparer T, Walzl G, Openshaw P, Dougan G. Mucosal delivery of a respiratory syncytial virus CTL peptide with enterotoxin-based adjuvants elicits protective, immunopathogenic, and immunoregulatory antiviral CD8+ T cell responses. J Immunol 2001; 166:1106-13. [PMID: 11145691 DOI: 10.4049/jimmunol.166.2.1106] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In an effort to develop a safe and effective vaccine against respiratory syncytial virus (RSV), we used Escherichia coli heat-labile toxin (LT), and LTK63 (an LT mutant devoid of ADP-ribosyltransferase activity) to elicit murine CD8(+) CTL responses to an intranasally codelivered CTL peptide from the second matrix protein (M2) of RSV. M2(82-90)-specific CD8(+) T cells were detected by IFN-gamma enzyme-linked immunospot and (51)Cr release assay in local and systemic lymph nodes, and their induction was dependent on the use of a mucosal adjuvant. CTL elicited by peptide immunization afforded protection against RSV challenge, but also enhanced weight loss. CTL-mediated viral clearance was not dependent on IFN-gamma since depletion using specific mAb during RSV challenge did not affect cellular recruitment or viral clearance. Depletion of IFN-gamma did, however, reduce the concentration of TNF detected in lung homogenates of challenged mice and largely prevented the weight loss associated with CTL-mediated viral clearance. Mice primed with the attachment glycoprotein (G) develop lung eosinophilia after intranasal RSV challenge. Mucosal peptide vaccination reduced pulmonary eosinophilia in mice subsequently immunized with G and challenged with RSV. These studies emphasize that protective and immunoregulatory CD8(+) CTL responses can be mucosally elicited using enterotoxin-based mucosal adjuvants but that resistance against viral infection may be accompanied by enhanced disease.
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Affiliation(s)
- C P Simmons
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, South Kensington, London, United Kingdom.
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Khan SA, Strijbos PJ, Everest P, Moss D, Stratford R, Mastroeni P, Allen J, Servos S, Charles IG, Dougan G, Maskell DJ. Early responses to Salmonella typhimurium infection in mice occur at focal lesions in infected organs. Microb Pathog 2001; 30:29-38. [PMID: 11162183 DOI: 10.1006/mpat.2000.0405] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Salmonella typhimurium causes an invasive disease in mice that has similarities to human typhoid, with key roles for cytokines and possibly also inducible nitric oxide synthase (iNOS), in mediating host responses to infection. In this paper we demonstrate that iNOS mRNA, protein and enzyme activity is induced within spleens and livers of infected mice as early as 5 h post-infection. Immunohistochemistry and in situ hybridization indicated that iNOS expression occurs predominantly in macrophages in localized, discrete foci in the infected organs. iNOS activity in spleen and liver was not detectable in uninfected control mice. The presence of mRNA encoding pro-inflammatory cytokines (TNFalpha, IL-1beta and IFNgamma) in infected organs was measured using RT-PCR, all three being present from 2 h post-infection onwards, but not before. These data show that there is a very early host response to S. typhimurium infection in mice, limited to foci within the infected organs.
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Affiliation(s)
- S A Khan
- Department of Clinical Veterinary Medicine, The Centre for Veterinary Science, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.
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McClelland M, Florea L, Sanderson K, Clifton SW, Parkhill J, Churcher C, Dougan G, Wilson RK, Miller W. Comparison of the Escherichia coli K-12 genome with sampled genomes of a Klebsiella pneumoniae and three salmonella enterica serovars, Typhimurium, Typhi and Paratyphi. Nucleic Acids Res 2000; 28:4974-86. [PMID: 11121489 PMCID: PMC115240 DOI: 10.1093/nar/28.24.4974] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The Escherichia coli K-12 genome (ECO) was compared with the sampled genomes of the sibling species Salmonella enterica serovars Typhimurium, Typhi and Paratyphi A (collectively referred to as SAL) and the genome of the close outgroup Klebsiella pneumoniae (KPN). There are at least 160 locations where sequences of >400 bp are absent from ECO but present in the genomes of all three SAL and 394 locations where sequences are present in ECO but close homologs are absent in all SAL genomes. The 394 sequences in ECO that do not occur in SAL contain 1350 (30.6%) of the 4405 ECO genes. Of these, 1165 are missing from both SAL and KPN. Most of the 1165 genes are concentrated within 28 regions of 10-40 kb, which consist almost exclusively of such genes. Among these regions were six that included previously identified cryptic phage. A hypothetical ancestral state of genomic regions that differ between ECO and SAL can be inferred in some cases by reference to the genome structure in KPN and the more distant relative Yersinia pestis. However, many changes between ECO and SAL are concentrated in regions where all four genera have a different structure. The rate of gene insertion and deletion is sufficiently high in these regions that the ancestral state of the ECO/SAL lineage cannot be inferred from the present data. The sequencing of other closely related genomes, such as S.bongori or Citrobacter, may help in this regard.
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Affiliation(s)
- M McClelland
- Sidney Kimmel Cancer Center, 10835 Altman Row, San Diego, CA 92121, USA
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50
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Abstract
Escherichia coli heat-labile enterotoxin (LT) is an extensively studied adjuvant of mucosal responses. Nevertheless, its mode of action as an adjuvant remains incompletely understood. In this study, we describe a simplified in vitro model with which to look at some aspects of immunoregulation by LT. The interaction of LT with the apical surface of a monolayer of CaCo-2 epithelial cells induces the release of a soluble factor which inhibits the antigen-induced release of interleukin-2 by T cells cultured at the basolateral side of the cells. The release of this factor requires the ADP-ribosylating activity of LT since the isolated B subunit, as well as an enzymatically silent LT mutant, loses biological activity in this model. The inhibitory activity is likely to be due to prostaglandin release, since it is blocked by indomethacin. The contribution of LT-induced prostaglandin release to the complex immunoregulatory activity of LT is discussed.
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Affiliation(s)
- L M Lopes
- Department of Immunology, Windeyer Institute of Medical Sciences, University College London, London W1P 6DB, United Kingdom
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