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Jenkins CH, Scott AE, O’Neill PA, Norville IH, Prior JL, Ireland PM. The Arabinose 5-Phosphate Isomerase KdsD Is Required for Virulence in Burkholderia pseudomallei. J Bacteriol 2023; 205:e0003423. [PMID: 37458584 PMCID: PMC10448790 DOI: 10.1128/jb.00034-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/06/2023] [Indexed: 08/25/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, which is endemic primarily in Southeast Asia and northern Australia but is increasingly being seen in other tropical and subtropical regions of the world. Melioidosis is associated with high morbidity and mortality rates, which is mediated by the wide range of virulence factors encoded by B. pseudomallei. These virulence determinants include surface polysaccharides such as lipopolysaccharide (LPS) and capsular polysaccharides (CPS). Here, we investigated a predicted arabinose-5-phosphate isomerase (API) similar to KdsD in B. pseudomallei strain K96243. KdsD is required for the production of the highly conserved 3-deoxy-d-manno-octulosonic acid (Kdo), a key sugar in the core region of LPS. Recombinant KdsD was expressed and purified, and API activity was determined. Although a putative API paralogue (KpsF) is also predicted to be encoded, the deletion of kdsD resulted in growth defects, loss of motility, reduced survival in RAW 264.7 murine macrophages, and attenuation in a BALB/c mouse model of melioidosis. Suppressor mutations were observed during a phenotypic screen for motility, revealing single nucleotide polymorphisms or indels located in the poorly understood CPS type IV cluster. Crucially, suppressor mutations did not result in reversion of attenuation in vivo. This study demonstrates the importance of KdsD for B. pseudomallei virulence and highlights further the complex nature of the polysaccharides it produces. IMPORTANCE The intrinsic resistance of B. pseudomallei to many antibiotics complicates treatment. This opportunistic pathogen possesses a wide range of virulence factors, resulting in severe and potentially fatal disease. Virulence factors as targets for drug development offer an alternative approach to combat pathogenic bacteria. Prior to initiating early drug discovery approaches, it is important to demonstrate that disruption of the target gene will prevent the development of disease. This study highlights the fact that KdsD is crucial for virulence of B. pseudomallei in an animal model of infection and provides supportive phenotypic characterization that builds a foundation for future therapeutic development.
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Affiliation(s)
- Christopher H. Jenkins
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Andrew E. Scott
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Paul A. O’Neill
- University of Exeter Sequencing Service, Exeter, United Kingdom
| | - Isobel H. Norville
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
| | - Joann L. Prior
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
- Southampton General Hospital, Southampton, United Kingdom
| | - Philip M. Ireland
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
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Cross AR, Roy S, Vivoli Vega M, Rejzek M, Nepogodiev SA, Cliff M, Salmon D, Isupov MN, Field RA, Prior JL, Harmer NJ. Spinning sugars in antigen biosynthesis: characterization of the Coxiella burnetii and Streptomyces griseus TDP-sugar epimerases. J Biol Chem 2022; 298:101903. [PMID: 35398092 PMCID: PMC9095892 DOI: 10.1016/j.jbc.2022.101903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/19/2021] [Revised: 04/02/2022] [Accepted: 04/04/2022] [Indexed: 11/25/2022] Open
Abstract
The sugars streptose and dihydrohydroxystreptose (DHHS) are unique to the bacteria Streptomyces griseus and Coxiella burnetii, respectively. Streptose forms the central moiety of the antibiotic streptomycin, while DHHS is found in the O-antigen of the zoonotic pathogen C. burnetii. Biosynthesis of these sugars has been proposed to follow a similar path to that of TDP-rhamnose, catalyzed by the enzymes RmlA, RmlB, RmlC, and RmlD, but the exact mechanism is unclear. Streptose and DHHS biosynthesis unusually requires a ring contraction step that could be performed by orthologs of RmlC or RmlD. Genome sequencing of S. griseus and C. burnetii has identified StrM and CBU1838 proteins as RmlC orthologs in these respective species. Here, we demonstrate that both enzymes can perform the RmlC 3'',5'' double epimerization activity necessary to support TDP-rhamnose biosynthesis in vivo. This is consistent with the ring contraction step being performed on a double epimerized substrate. We further demonstrate that proton exchange is faster at the 3''-position than the 5''-position, in contrast to a previously studied ortholog. We additionally solved the crystal structures of CBU1838 and StrM in complex with TDP and show that they form an active site highly similar to those of the previously characterized enzymes RmlC, EvaD, and ChmJ. These results support the hypothesis that streptose and DHHS are biosynthesized using the TDP pathway and that an RmlD paralog most likely performs ring contraction following double epimerization. This work will support the elucidation of the full pathways for biosynthesis of these unique sugars.
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Affiliation(s)
- Alice R Cross
- Living Systems Institute, University of Exeter, Exeter, United Kingdom; Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Sumita Roy
- Living Systems Institute, University of Exeter, Exeter, United Kingdom; Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Mirella Vivoli Vega
- Living Systems Institute, University of Exeter, Exeter, United Kingdom; Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Martin Rejzek
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, United Kingdom
| | - Sergey A Nepogodiev
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, United Kingdom
| | - Matthew Cliff
- Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom
| | - Debbie Salmon
- Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Michail N Isupov
- Department of Biosciences, University of Exeter, Exeter, United Kingdom
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Colney Lane, Norwich, United Kingdom; Manchester Institute of Biotechnology, University of Manchester, Manchester, United Kingdom
| | - Joann L Prior
- Dstl, Porton Down, Salisbury, Wiltshire, United Kingdom
| | - Nicholas J Harmer
- Living Systems Institute, University of Exeter, Exeter, United Kingdom; Department of Biosciences, University of Exeter, Exeter, United Kingdom.
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Porges E, Jenner D, Taylor AW, Harrison JS, De Grazia A, Hailes AR, Wright KM, Whelan AO, Norville IH, Prior JL, Mahajan S, Rowland CA, Newman TA, Evans ND. Antibiotic-Loaded Polymersomes for Clearance of Intracellular Burkholderia thailandensis. ACS Nano 2021; 15:19284-19297. [PMID: 34739227 PMCID: PMC7612142 DOI: 10.1021/acsnano.1c05309] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Melioidosis caused by the facultative intracellular pathogen Burkholderia pseudomallei is difficult to treat due to poor intracellular bioavailability of antibiotics and antibiotic resistance. In the absence of novel compounds, polymersome (PM) encapsulation may increase the efficacy of existing antibiotics and reduce antibiotic resistance by promoting targeted, infection-specific intracellular uptake. In this study, we developed PMs composed of widely available poly(ethylene oxide)-polycaprolactone block copolymers and demonstrated their delivery to intracellular B. thailandensis infection using multispectral imaging flow cytometry (IFC) and coherent anti-Stokes Raman scattering microscopy. Antibiotics were tightly sequestered in PMs and did not inhibit the growth of free-living B. thailandensis. However, on uptake of antibiotic-loaded PMs by infected macrophages, IFC demonstrated PM colocalization with intracellular B. thailandensis and a significant inhibition of their growth. We conclude that PMs are a viable approach for the targeted antibiotic treatment of persistent intracellular Burkholderia infection.
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Affiliation(s)
- Eleanor Porges
- Bioengineering Sciences Group, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Centre for Human Development, Stem Cells and Regeneration, Bone and Joint Research Group, University of Southampton Faculty of Medicine, Southampton, SO16 6YD,United Kingdom
- Clinical and Experimental Sciences, Faculty of Medicine, Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Dominic Jenner
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Adam W. Taylor
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
- London School of Hygiene and Tropical Medicine, London, WC1E 7HT, United Kingdom
| | - James S.P. Harrison
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Antonio De Grazia
- Bioengineering Sciences Group, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Clinical and Experimental Sciences, Faculty of Medicine, Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
| | - Alethia R. Hailes
- Bioengineering Sciences Group, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Centre for Human Development, Stem Cells and Regeneration, Bone and Joint Research Group, University of Southampton Faculty of Medicine, Southampton, SO16 6YD,United Kingdom
- Clinical and Experimental Sciences, Faculty of Medicine, Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Kimberley M. Wright
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Adam O. Whelan
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Isobel H. Norville
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Sumeet Mahajan
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- School of Chemistry, Faculty of Engineering and Physical Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Caroline A. Rowland
- Defence Science and Technology Laboratory, Chemical, Biological and Radiological Division, Porton Down, Salisbury, SP4 0JQ, United Kingdom
| | - Tracey A. Newman
- Clinical and Experimental Sciences, Faculty of Medicine, Institute for Life Sciences, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Nicholas D. Evans
- Bioengineering Sciences Group, Faculty of Engineering and the Environment, University of Southampton, Highfield, Southampton, SO17 1BJ, United Kingdom
- Centre for Human Development, Stem Cells and Regeneration, Bone and Joint Research Group, University of Southampton Faculty of Medicine, Southampton, SO16 6YD,United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
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Reddi D, Durant L, Bernardo D, Noble A, English NR, Hendy P, Clark GC, Prior JL, Williamson ED, Knight SC. In Vitro Priming of Human T Cells by Dendritic Cells Provides a Screening Tool for Candidate Vaccines for Burkholderia pseudomallei. Vaccines (Basel) 2021; 9:929. [PMID: 34452057 PMCID: PMC8402564 DOI: 10.3390/vaccines9080929] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/10/2021] [Accepted: 08/18/2021] [Indexed: 11/29/2022] Open
Abstract
Murine dendritic cells, when pulsed with heat-killed Burkholderia pseudomallei and used to immunise naïve mice, have previously been shown to induce protective immunity in vivo. We have now demonstrated the in vitro priming of naïve human T cells against heat-killed B. pseudomallei, by co-culture with syngeneic B. pseudomallei-pulsed dendritic cells. Additionally, we have enriched the DC fraction such that a study of the differential response induced by pulsed DCs of either myeloid or plasmacytoid lineage in syngeneic human T cells was achievable. Whilst both mDCs and pDCs were activated by pulsing, the mDCs contributed the major response to B. pseudomallei with the expression of the migration marker CCR7 and a significantly greater secretion of the proinflammatory TNFα and IL1β. When these DC factions were combined and used to prime syngeneic T cells, a significant proliferation was observed in the CD4+ fraction. Here, we have achieved human T cell priming in vitro with unadjuvanted B. pseudomallei, the causative organism of melioidosis, for which there is currently no approved vaccine. We propose that the approach we have taken could be used to screen for the human cellular response to candidate vaccines and formulations, in order to enhance the cell-mediated immunity required to protect against this intracellular pathogen and potentially more broadly against other, difficult-to-treat intracellular pathogens. To date, the polysaccharide capsule of B. pseudomallei, fused to a standard carrier protein, e.g., Crm, looks a likely vaccine candidate. Dendritic cells (DCs), providing, as they do, the first line of defence to infection, process and present microbial products to the immune system to direct downstream immune responses. Here, we have sought to use DCs ex vivo to identify immunogenic products from heat-killed B. pseudomallei. Using practical volumes of fresh human donor blood, we show that heat-killed B. pseudomallei activated and stimulated the expression of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 from both myeloid and plasmacytoid DCs. Furthermore, B. pseudomallei-pulsed DCs cultured with naïve syngeneic T cells ex vivo, induced the activation and proliferation of the CD4+ T-cell population, which was identified by cell surface marker staining using flow cytometry. Thus, both DC subsets are important for driving primary T helper cell responses to B. pseudomallei in healthy individuals and have the potential to be used to identify immunogenic components of B. pseudomallei for future therapies and vaccines.
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Affiliation(s)
- Durga Reddi
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
| | - Lydia Durant
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
| | - David Bernardo
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
| | - Alistair Noble
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
- Gut Microbes & Health Program, Quadram Institute Bioscience, Norwich NR4 7UQ, UK
| | - Nicholas R. English
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
| | - Philip Hendy
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
- St Mark’s Hospital, London North West University Healthcare NHS Trust, Harrow UT 84124, UK
| | - Graeme C. Clark
- Defence Science and Technology Laboratory, Porton Down SP4 0JQ, UK; (G.C.C.); (J.L.P.)
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down SP4 0JQ, UK; (G.C.C.); (J.L.P.)
| | | | - Stella C. Knight
- Antigen Presentation Research Group, Imperial Centre for Translational and Experimental Medicine, 72 Du Cane Road, London W12 0NN, UK; (D.R.); (L.D.); (D.B.); (A.N.); (N.R.E.); (P.H.); (S.C.K.)
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5
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Hartley MG, Ralph E, Norville IH, Prior JL, Atkins TP. Comparison of PCR and Viable Count as a Method for Enumeration of Bacteria in an A/J Mouse Aerosol Model of Q Fever. Front Microbiol 2019; 10:1552. [PMID: 31379760 PMCID: PMC6647910 DOI: 10.3389/fmicb.2019.01552] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 06/21/2019] [Indexed: 12/26/2022] Open
Abstract
Historically, disease progression in animal models of Q fever has been carried out using PCR to monitor the presence of Coxiella burnetii DNA in the host. However, the colonization and dissemination of other bacterial infections in animal models are tracked using viable counts, enabling an accurate assessment of viable bacterial load within tissues. Following recent advances in the culture methods, it has become possible to do the same with C. burnetii. Here we compare and contrast the different information gained by using PCR or viable counts to study this disease. Viable bacteria were cleared from organs much faster than previously reported when assessed by bacterial DNA, but weight loss and clinical signs improved while animals were still heavily infected.
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Affiliation(s)
- M Gill Hartley
- CBR, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Esther Ralph
- CBR, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Isobel H Norville
- CBR, Defence Science and Technology Laboratory, Salisbury, United Kingdom
| | - Joann L Prior
- CBR, Defence Science and Technology Laboratory, Salisbury, United Kingdom.,College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Timothy P Atkins
- CBR, Defence Science and Technology Laboratory, Salisbury, United Kingdom.,College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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6
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Kovacs-Simon A, Hemsley CM, Scott AE, Prior JL, Titball RW. Burkholderia thailandensis strain E555 is a surrogate for the investigation of Burkholderia pseudomallei replication and survival in macrophages. BMC Microbiol 2019; 19:97. [PMID: 31092204 PMCID: PMC6521459 DOI: 10.1186/s12866-019-1469-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/30/2019] [Indexed: 02/02/2023] Open
Abstract
Background Burkholderia pseudomallei is a human pathogen causing severe infections in tropical and subtropical regions and is classified as a bio-threat agent. B. thailandensis strain E264 has been proposed as less pathogenic surrogate for understanding the interactions of B. pseudomallei with host cells. Results We show that, unlike B. thailandensis strain E264, the pattern of growth of B. thailandensis strain E555 in macrophages is similar to that of B. pseudomallei. We have genome sequenced B. thailandensis strain E555 and using the annotated sequence identified genes and proteins up-regulated during infection. Changes in gene expression identified more of the known B. pseudomallei virulence factors than changes in protein levels and used together we identified 16% of the currently known B. pseudomallei virulence factors. These findings demonstrate the utility of B. thailandensis strain E555 to study virulence of B. pseudomallei. Conclusions A weakness of studies using B. thailandensis as a surrogate for B. pseudomallei is that the strains used replicate at a slower rate in infected cells. We show that the pattern of growth of B. thailandensis strain E555 in macrophages closely mirrors that of B. pseudomallei. Using this infection model we have shown that virulence factors of B. pseudomallei can be identified as genes or proteins whose expression is elevated on the infection of macrophages. This finding confirms the utility of B. thailandensis strain E555 as a surrogate for B. pseudomallei and this strain should be used for future studies on virulence mechanisms. Electronic supplementary material The online version of this article (10.1186/s12866-019-1469-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- A Kovacs-Simon
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - C M Hemsley
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - A E Scott
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, UK
| | - J L Prior
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.,CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, UK
| | - R W Titball
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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Abstract
One Health is an effective approach for the management of zoonotic disease in humans, animals and environments. Examples of the management of bacterial zoonoses in Europe and across the globe demonstrate that One Health approaches of international surveillance, information-sharing and appropriate intervention methods are required to successfully prevent and control disease outbreaks in both endemic and non-endemic regions. Additionally, a One Health approach enables effective preparation and response to bioterrorism threats.
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Affiliation(s)
- Alice R Cross
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom.
| | - Victoria M Baldwin
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ United Kingdom
| | - Sumita Roy
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom
| | | | - Joann L Prior
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom; Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ United Kingdom; London School of Hygiene & Tropical Medicine, Kepple Street, London WC1E 7HT United Kingdom
| | - Nicholas J Harmer
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom
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Bayliss M, Donaldson MI, Nepogodiev SA, Pergolizzi G, Scott AE, Harmer NJ, Field RA, Prior JL. Structural characterisation of the capsular polysaccharide expressed by Burkholderia thailandensis strain E555:: wbiI (pKnock-KmR) and assessment of the significance of the 2-O-acetyl group in immune protection. Carbohydr Res 2017; 452:17-24. [PMID: 29024844 PMCID: PMC5697523 DOI: 10.1016/j.carres.2017.09.011] [Citation(s) in RCA: 15] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 09/18/2017] [Accepted: 09/19/2017] [Indexed: 11/19/2022]
Abstract
Burkholderia pseudomallei and its close relative B. mallei are human pathogens that are classified as Tier 1 bio-threat agents. Both organisms have previously been shown to constitutively produce a capsular polysaccharide (CPS) that is both a virulence determinant and protective antigen. Extraction and purification of CPS for use as a potential vaccine candidate requires containment level 3 laboratories which is expensive and time-consuming. B. thailandensis strain E555 is closely related to B. pseudomallei and B. mallei, but is non-pathogenic to humans and based on immunological cross-reactivity has previously been shown to express a B. pseudomallei-like CPS. In this study, capsular polysaccharide isolated from an O-antigen deficient strain of B. thailandensis E555 was identified by 1H and 13C NMR spectroscopy as -3-)-2-O-acetyl-6-deoxy-β-d-manno-heptopyranose-(-1, and identical to that produced by B. pseudomallei. This was further substantiated by anti-CPS monoclonal antibody binding. In connection with the production of CPS fragments for use in glycoconjugate vaccines, we set out to assess the importance or otherwise of the CPS 2-OAc groups in immune protection. To this end conjugates of the native and de-O-acetylated CPS with the Hc fragment of tetanus toxin (TetHc) were used as vaccines in a mouse model of melioidosis. The level of protection provided by deacetylated CPS was significantly lower than that from native, acetylated CPS. In addition, sera from mice vaccinated with the deacetylated CPS conjugate did not recognise native CPS. This suggests that CPS extracted from B. thailandensis can be used as antigen and that the acetyl group is essential for protection.
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Affiliation(s)
- Marc Bayliss
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK.
| | - Matthew I Donaldson
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Sergey A Nepogodiev
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Giulia Pergolizzi
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK
| | - Andrew E Scott
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK
| | - Nicholas J Harmer
- Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Robert A Field
- Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich, NR4 7UH, UK.
| | - Joann L Prior
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK; University of Exeter, Stocker Road, Exeter, EX4 4QD, UK; London School of Hygiene and Tropical Medicine, Keppler Street, London, WC1 7HT, UK
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9
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Cizmeci D, Dempster EL, Champion OL, Wagley S, Akman OE, Prior JL, Soyer OS, Mill J, Titball RW. Mapping epigenetic changes to the host cell genome induced by Burkholderia pseudomallei reveals pathogen-specific and pathogen-generic signatures of infection. Sci Rep 2016; 6:30861. [PMID: 27484700 PMCID: PMC4971488 DOI: 10.1038/srep30861] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 07/07/2016] [Indexed: 01/26/2023] Open
Abstract
The potential for epigenetic changes in host cells following microbial infection has been widely suggested, but few examples have been reported. We assessed genome-wide patterns of DNA methylation in human macrophage-like U937 cells following infection with Burkholderia pseudomallei, an intracellular bacterial pathogen and the causative agent of human melioidosis. Our analyses revealed significant changes in host cell DNA methylation, at multiple CpG sites in the host cell genome, following infection. Infection induced differentially methylated probes (iDMPs) showing the greatest changes in DNA methylation were found to be in the vicinity of genes involved in inflammatory responses, intracellular signalling, apoptosis and pathogen-induced signalling. A comparison of our data with reported methylome changes in cells infected with M. tuberculosis revealed commonality of differentially methylated genes, including genes involved in T cell responses (BCL11B, FOXO1, KIF13B, PAWR, SOX4, SYK), actin cytoskeleton organisation (ACTR3, CDC42BPA, DTNBP1, FERMT2, PRKCZ, RAC1), and cytokine production (FOXP1, IRF8, MR1). Overall our findings show that pathogenic-specific and pathogen-common changes in the methylome occur following infection.
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Affiliation(s)
- Deniz Cizmeci
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
| | - Emma L Dempster
- University of Exeter Medical School, Exeter University, Exeter, United Kingdom
| | - Olivia L Champion
- College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Sariqa Wagley
- College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Ozgur E Akman
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
| | - Joann L Prior
- College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
| | - Orkun S Soyer
- School of Life Sciences, University of Warwick, United Kingdom
| | - Jonathan Mill
- University of Exeter Medical School, Exeter University, Exeter, United Kingdom.,Institute of Psychiatry, Psychology &Neuroscience, King's College London, United Kingdom
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom
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10
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Vivoli M, Isupov MN, Nicholas R, Hill A, Scott AE, Kosma P, Prior JL, Harmer NJ. Unraveling the B. pseudomallei Heptokinase WcbL: From Structure to Drug Discovery. ACTA ACUST UNITED AC 2016; 22:1622-32. [PMID: 26687481 PMCID: PMC4691232 DOI: 10.1016/j.chembiol.2015.10.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 10/20/2015] [Accepted: 10/31/2015] [Indexed: 11/25/2022]
Abstract
Gram-negative bacteria utilize heptoses as part of their repertoire of extracellular polysaccharide virulence determinants. Disruption of heptose biosynthesis offers an attractive target for novel antimicrobials. A critical step in the synthesis of heptoses is their 1-O phosphorylation, mediated by kinases such as HldE or WcbL. Here, we present the structure of WcbL from Burkholderia pseudomallei. We report that WcbL operates through a sequential ordered Bi-Bi mechanism, loading the heptose first and then ATP. We show that dimeric WcbL binds ATP anti-cooperatively in the absence of heptose, and cooperatively in its presence. Modeling of WcbL suggests that heptose binding causes an elegant switch in the hydrogen-bonding network, facilitating the binding of a second ATP molecule. Finally, we screened a library of drug-like fragments, identifying hits that potently inhibit WcbL. Our results provide a novel mechanism for control of substrate binding and emphasize WcbL as an attractive anti-microbial target for Gram-negative bacteria.
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Affiliation(s)
- Mirella Vivoli
- Department of Biosciences, University of Exeter, Henry Wellcome Building, Stocker Road, Exeter EX4 4QD, UK
| | - Michail N Isupov
- Department of Biosciences, University of Exeter, Henry Wellcome Building, Stocker Road, Exeter EX4 4QD, UK
| | - Rebecca Nicholas
- Department of Biosciences, University of Exeter, Henry Wellcome Building, Stocker Road, Exeter EX4 4QD, UK
| | - Andrew Hill
- Department of Biosciences, University of Exeter, Henry Wellcome Building, Stocker Road, Exeter EX4 4QD, UK
| | - Andrew E Scott
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Paul Kosma
- University of Natural Resources and Life Sciences-Vienna, Muthgasse 18, 1190 Vienna, Austria
| | - Joann L Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Nicholas J Harmer
- Department of Biosciences, University of Exeter, Henry Wellcome Building, Stocker Road, Exeter EX4 4QD, UK.
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11
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Scott AE, Christ WJ, George AJ, Stokes MGM, Lohman GJS, Guo Y, Jones M, Titball RW, Atkins TP, Campbell AS, Prior JL. Protection against Experimental Melioidosis with a Synthetic manno-Heptopyranose Hexasaccharide Glycoconjugate. Bioconjug Chem 2016; 27:1435-46. [PMID: 27124182 PMCID: PMC4911622 DOI: 10.1021/acs.bioconjchem.5b00525] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
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Melioidosis is an emerging infectious
disease caused by Burkholderia pseudomallei and is associated with
high morbidity and mortality rates in endemic areas. Antibiotic treatment
is protracted and not always successful; even with appropriate therapy,
up to 40% of individuals presenting with melioidosis in Thailand succumb
to infection. In these circumstances, an effective vaccine has the
potential to have a dramatic impact on both the scale and the severity
of disease. Currently, no vaccines are licensed for human use. A leading
vaccine candidate is the capsular polysaccharide consisting of a homopolymer
of unbranched 1→3 linked 2-O-acetyl-6-deoxy-β-d-manno-heptopyranose. Here, we present the
chemical synthesis of this challenging antigen using a novel modular
disaccharide assembly approach. The resulting hexasaccharide was coupled
to the nontoxic Hc domain of tetanus toxin as a carrier
protein to promote recruitment of T-cell help and provide a scaffold
for antigen display. Mice immunized with the glycoconjugate developed
IgM and IgG responses capable of recognizing native capsule, and were
protected against infection with over 120 × LD50 of B. pseudomallei strain K96243. This is the first
report of the chemical synthesis of an immunologically relevant and
protective hexasaccharide fragment of the capsular polysaccharide
of B. pseudomallei and serves as the
rational starting point for the development of an effective licensed
vaccine for this emerging infectious disease.
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Affiliation(s)
- Andrew E Scott
- Defence Science and Technology Laboratory , Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - William J Christ
- Corden Pharma International Inc. (formerly Ancora Pharmaceuticals Inc.) , Woburn, Massachusetts 01801 United States
| | - Alison J George
- Defence Science and Technology Laboratory , Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Margaret G M Stokes
- Defence Science and Technology Laboratory , Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Gregory J S Lohman
- Corden Pharma International Inc. (formerly Ancora Pharmaceuticals Inc.) , Woburn, Massachusetts 01801 United States
| | - Yuhong Guo
- Corden Pharma International Inc. (formerly Ancora Pharmaceuticals Inc.) , Woburn, Massachusetts 01801 United States
| | - Matthew Jones
- Corden Pharma International Inc. (formerly Ancora Pharmaceuticals Inc.) , Woburn, Massachusetts 01801 United States
| | - Richard W Titball
- College of Life and Environmental Sciences, University of Exeter , Exeter, Devon EX4 4QD, United Kingdom
| | - Timothy P Atkins
- Defence Science and Technology Laboratory , Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - A Stewart Campbell
- Corden Pharma International Inc. (formerly Ancora Pharmaceuticals Inc.) , Woburn, Massachusetts 01801 United States
| | - Joann L Prior
- Defence Science and Technology Laboratory , Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
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12
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Weehuizen TAF, Prior JL, van der Vaart TW, Ngugi SA, Nepogodiev SA, Field RA, Kager LM, van ‘t Veer C, de Vos AF, Wiersinga WJ. Differential Toll-Like Receptor-Signalling of Burkholderia pseudomallei Lipopolysaccharide in Murine and Human Models. PLoS One 2015; 10:e0145397. [PMID: 26689559 PMCID: PMC4687033 DOI: 10.1371/journal.pone.0145397] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 12/03/2015] [Indexed: 11/19/2022] Open
Abstract
The Gram-negative bacterium Burkholderia pseudomallei causes melioidosis and is a CDC category B bioterrorism agent. Toll-like receptor (TLR)-2 impairs host defense during pulmonary B.pseudomallei infection while TLR4 only has limited impact. We investigated the role of TLRs in B.pseudomallei-lipopolysaccharide (LPS) induced inflammation. Purified B.pseudomallei-LPS activated only TLR2-transfected-HEK-cells during short stimulation but both HEK-TLR2 and HEK-TLR4-cells after 24 h. In human blood, an additive effect of TLR2 on TLR4-mediated signalling induced by B.pseudomallei-LPS was observed. In contrast, murine peritoneal macrophages recognized B.pseudomallei-LPS solely through TLR4. Intranasal inoculation of B.pseudomallei-LPS showed that both TLR4-knockout(-/-) and TLR2x4-/-, but not TLR2-/- mice, displayed diminished cytokine responses and neutrophil influx compared to wild-type controls. These data suggest that B.pseudomallei-LPS signalling occurs solely through murine TLR4, while in human models TLR2 plays an additional role, highlighting important differences between specificity of human and murine models that may have important consequences for B.pseudomallei-LPS sensing by TLRs and subsequent susceptibility to melioidosis.
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Affiliation(s)
- Tassili A. F. Weehuizen
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | - Thomas W. van der Vaart
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Sarah A. Ngugi
- Defence Science and Technology Laboratory, Porton Down, Salisbury, United Kingdom
| | | | - Robert A. Field
- John Innes Centre, Norwich Research Park, Colney, United Kingdom
| | - Liesbeth M. Kager
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Cornelis van ‘t Veer
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - Alex F. de Vos
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
| | - W. Joost Wiersinga
- Center for Infection and Immunity Amsterdam (CINIMA), Academic Medical Center, Amsterdam, the Netherlands
- Center for Experimental and Molecular Medicine (CEMM), Academic Medical Center, Amsterdam, the Netherlands
- Department of Internal Medicine, Division of Infectious Diseases, Academic Medical Center, Amsterdam, the Netherlands
- * E-mail: (TAFW); (WJW)
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13
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Adler NRL, Stevens MP, Dean RE, Saint RJ, Pankhania D, Prior JL, Atkins TP, Kessler B, Nithichanon A, Lertmemongkolchai G, Galyov EE. Systematic mutagenesis of genes encoding predicted autotransported proteins of Burkholderia pseudomallei identifies factors mediating virulence in mice, net intracellular replication and a novel protein conferring serum resistance. PLoS One 2015; 10:e0121271. [PMID: 25830295 PMCID: PMC4382181 DOI: 10.1371/journal.pone.0121271] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 01/29/2015] [Indexed: 01/12/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of the severe tropical disease melioidosis, which commonly presents as sepsis. The B. pseudomallei K96243 genome encodes eleven predicted autotransporters, a diverse family of secreted and outer membrane proteins often associated with virulence. In a systematic study of these autotransporters, we constructed insertion mutants in each gene predicted to encode an autotransporter and assessed them for three pathogenesis-associated phenotypes: virulence in the BALB/c intra-peritoneal mouse melioidosis model, net intracellular replication in J774.2 murine macrophage-like cells and survival in 45% (v/v) normal human serum. From the complete repertoire of eleven autotransporter mutants, we identified eight mutants which exhibited an increase in median lethal dose of 1 to 2-log10 compared to the isogenic parent strain (bcaA, boaA, boaB, bpaA, bpaC, bpaE, bpaF and bimA). Four mutants, all demonstrating attenuation for virulence, exhibited reduced net intracellular replication in J774.2 macrophage-like cells (bimA, boaB, bpaC and bpaE). A single mutant (bpaC) was identified that exhibited significantly reduced serum survival compared to wild-type. The bpaC mutant, which demonstrated attenuation for virulence and net intracellular replication, was sensitive to complement-mediated killing via the classical and/or lectin pathway. Serum resistance was rescued by in trans complementation. Subsequently, we expressed recombinant proteins of the passenger domain of four predicted autotransporters representing each of the phenotypic groups identified: those attenuated for virulence (BcaA), those attenuated for virulence and net intracellular replication (BpaE), the BpaC mutant with defects in virulence, net intracellular replication and serum resistance and those displaying wild-type phenotypes (BatA). Only BcaA and BpaE elicited a strong IFN-γ response in a restimulation assay using whole blood from seropositive donors and were recognised by seropositive human sera from the endemic area. To conclude, several predicted autotransporters contribute to B. pseudomallei virulence and BpaC may do so by conferring resistance against complement-mediated killing.
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Affiliation(s)
- Natalie R. Lazar Adler
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Mark P. Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, United Kingdom
| | - Rachel E. Dean
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Richard J. Saint
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Depesh Pankhania
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Joann L. Prior
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Timothy P. Atkins
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | - Bianca Kessler
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Arnone Nithichanon
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Ganjana Lertmemongkolchai
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Edouard E. Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- * E-mail:
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14
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Lazar Adler NR, Dean RE, Saint RJ, Stevens MP, Prior JL, Atkins TP, Galyov EE. Identification of a predicted trimeric autotransporter adhesin required for biofilm formation of Burkholderia pseudomallei. PLoS One 2013; 8:e79461. [PMID: 24223950 PMCID: PMC3818227 DOI: 10.1371/journal.pone.0079461] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/23/2013] [Indexed: 01/25/2023] Open
Abstract
The autotransporters are a large and diverse family of bacterial secreted and outer membrane proteins, which are present in many Gram-negative bacterial pathogens and play a role in numerous environmental and virulence-associated interactions. As part of a larger systematic study on the autotransporters of Burkholderia pseudomallei, the causative agent of the severe tropical disease melioidosis, we have constructed an insertion mutant in the bpss1439 gene encoding an unstudied predicted trimeric autotransporter adhesin. The bpss1439 mutant demonstrated a significant reduction in biofilm formation at 48 hours in comparison to its parent 10276 wild-type strain. This phenotype was complemented to wild-type levels by the introduction of a full-length copy of the bpss1439 gene in trans. Examination of the wild-type and bpss1439 mutant strains under biofilm-inducing conditions by microscopy after 48 hours confirmed that the bpss1439 mutant produced less biofilm compared to wild-type. Additionally, it was observed that this phenotype was due to low levels of bacterial adhesion to the abiotic surface as well as reduced microcolony formation. In a murine melioidosis model, the bpss1439 mutant strain demonstrated a moderate attenuation for virulence compared to the wild-type strain. This attenuation was abrogated by in trans complementation, suggesting that bpss1439 plays a subtle role in the pathogenesis of B. pseudomallei. Taken together, these studies indicate that BPSS1439 is a novel predicted autotransporter involved in biofilm formation of B. pseudomallei; hence, this factor was named BbfA, Burkholderia biofilm factor A.
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Affiliation(s)
- Natalie R. Lazar Adler
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Rachel E. Dean
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Richard J. Saint
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Mark P. Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, United Kingdom
| | - Joann L. Prior
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Timothy P. Atkins
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | - Edouard E. Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- * E-mail:
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15
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Cuccui J, Thomas RM, Moule MG, D'Elia RV, Laws TR, Mills DC, Williamson D, Atkins TP, Prior JL, Wren BW. Exploitation of bacterial N-linked glycosylation to develop a novel recombinant glycoconjugate vaccine against Francisella tularensis. Open Biol 2013; 3:130002. [PMID: 23697804 PMCID: PMC3866875 DOI: 10.1098/rsob.130002] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [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: 01/04/2013] [Accepted: 05/01/2013] [Indexed: 11/12/2022] Open
Abstract
Glycoconjugate-based vaccines have proved to be effective at producing long-lasting protection against numerous pathogens. Here, we describe the application of bacterial protein glycan coupling technology (PGCT) to generate a novel recombinant glycoconjugate vaccine. We demonstrate the conjugation of the Francisella tularensis O-antigen to the Pseudomonas aeruginosa carrier protein exotoxin A using the Campylobacter jejuni PglB oligosaccharyltransferase. The resultant recombinant F. tularensis glycoconjugate vaccine is expressed in Escherichia coli where yields of 3 mg l(-1) of culture were routinely produced in a single-step purification process. Vaccination of BALB/c mice with the purified glycoconjugate boosted IgG levels and significantly increased the time to death upon subsequent challenge with F. tularensis subsp. holarctica. PGCT allows different polysaccharide and protein combinations to be produced recombinantly and could be easily applicable for the production of diverse glycoconjugate vaccines.
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Affiliation(s)
- Jon Cuccui
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Rebecca M. Thomas
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Madeleine G. Moule
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Riccardo V. D'Elia
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Thomas R. Laws
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Dominic C. Mills
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - Diane Williamson
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Timothy P. Atkins
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
- School of Biosciences, University of Exeter, Devon, UK
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Brendan W. Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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16
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Egge-Jacobsen W, Salomonsson EN, Aas FE, Forslund AL, Winther-Larsen HC, Maier J, Macellaro A, Kuoppa K, Oyston PCF, Titball RW, Thomas RM, Forsberg Å, Prior JL, Koomey M. O-linked glycosylation of the PilA pilin protein of Francisella tularensis: identification of the endogenous protein-targeting oligosaccharyltransferase and characterization of the native oligosaccharide. J Bacteriol 2011; 193:5487-97. [PMID: 21804002 PMCID: PMC3187425 DOI: 10.1128/jb.00383-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 07/20/2011] [Indexed: 12/22/2022] Open
Abstract
Findings from a number of studies suggest that the PilA pilin proteins may play an important role in the pathogenesis of disease caused by species within the genus Francisella. As such, a thorough understanding of PilA structure and chemistry is warranted. Here, we definitively identified the PglA protein-targeting oligosaccharyltransferase by virtue of its necessity for PilA glycosylation in Francisella tularensis and its sufficiency for PilA glycosylation in Escherichia coli. In addition, we used mass spectrometry to examine PilA affinity purified from Francisella tularensis subsp. tularensis and F. tularensis subsp. holarctica and demonstrated that the protein undergoes multisite, O-linked glycosylation with a pentasaccharide of the structure HexNac-Hex-Hex-HexNac-HexNac. Further analyses revealed microheterogeneity related to forms of the pentasaccharide carrying unusual moieties linked to the distal sugar via a phosphate bridge. Type A and type B strains of Francisella subspecies thus express an O-linked protein glycosylation system utilizing core biosynthetic and assembly pathways conserved in other members of the proteobacteria. As PglA appears to be highly conserved in Francisella species, O-linked protein glycosylation may be a feature common to members of this genus.
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Affiliation(s)
- Wolfgang Egge-Jacobsen
- Department of Molecular Biosciences
- Glyconor Mass Spectrometry & Proteomics Unit, University of Oslo, 0316 Oslo, Norway
| | | | - Finn Erik Aas
- Department of Molecular Biosciences
- Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway
| | - Anna-Lena Forslund
- CBRN Defence and Security, FOI Swedish Defence Research Agency, 901 82 Umeå, Sweden
| | - Hanne C. Winther-Larsen
- Department of Molecular Biosciences
- Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway
| | - Josef Maier
- IStLS Information Services to Life Science, 78727 Oberndorf, Germany
| | - Anna Macellaro
- CBRN Defence and Security, FOI Swedish Defence Research Agency, 901 82 Umeå, Sweden
| | - Kerstin Kuoppa
- CBRN Defence and Security, FOI Swedish Defence Research Agency, 901 82 Umeå, Sweden
| | - Petra C. F. Oyston
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Richard W. Titball
- School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Rebecca M. Thomas
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Åke Forsberg
- Umeå Centre for Microbial Research (UCMR) and Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
| | - Joann L. Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
| | - Michael Koomey
- Department of Molecular Biosciences
- Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway
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17
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Qazi O, Rani M, Gnanam AJ, Cullen TW, Stead CM, Kensing H, McCaul K, Ngugi S, Prior JL, Lipka A, Nagy JM, Whitlock GC, Judy BM, Harding SV, Titball RW, Sidhu SS, Trent MS, Kitto GB, Torres A, Estes DM, Iverson B, Georgiou G, Brown KA. Development of reagents and assays for the detection of pathogenic Burkholderia species. Faraday Discuss 2011; 149:23-36; discussion 63-77. [PMID: 21413172 PMCID: PMC3593192 DOI: 10.1039/c005422b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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: 11/21/2022]
Abstract
Rapid detection of the category B biothreat agents Burkholderia pseudomallei and Burkholderia mallei in acute infections is critical to ensure that appropriate treatment is administered quickly to reduce an otherwise high probability of mortality (ca. 40% for B. pseudomallei). We are developing assays that can be used in clinical laboratories or security applications for the direct detection of surface-localized and secreted macromolecules produced by these organisms. We present our current medium-throughout approach for target selection and production of Burkholderia macromolecules and describe the generation of a Fab molecule targeted to the B. mallei BimA protein. We also present development of prototype assays for detecting Burkholderia species using anti-lipopolysaccharide antibodies.
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Affiliation(s)
- Omar Qazi
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Mridula Rani
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Annie J. Gnanam
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Thomas W. Cullen
- Section of Molecular Genetics and Microbiology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Christopher M. Stead
- Section of Molecular Genetics and Microbiology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Haley Kensing
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Kate McCaul
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Sarah Ngugi
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Joann L Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Alexandria Lipka
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ; Deceased, UK
| | - Judit M. Nagy
- Institute of Biomedical Engineering and the Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, UK
| | - Gregory C. Whitlock
- Department of Clinical Laboratory Sciences, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Barbara M. Judy
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Sarah V. Harding
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Richard W. Titball
- School of Biosciences, Geoffrey Pope Building, University of Exeter EX4 4QD, UK
| | - Sachdev S. Sidhu
- Terence Donnelly Center for Cellular and Biomolecular Research, Banting and Best Department of Biomedical Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - M. Stephen Trent
- Section of Molecular Genetics and Microbiology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - G Barrie Kitto
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - Alfredo Torres
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555, USA
- Department of Microbiology and Immunology and the Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - D. Mark Estes
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas 77555, USA
- Department of Microbiology and Immunology and the Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, Texas 77555, USA
| | - Brent Iverson
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
| | - George Georgiou
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Department of Chemical Engineering and Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Katherine A. Brown
- Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
- Department of Life Sciences, Imperial College London, Exhibition Road, London SW7 2AZ; Deceased, UK
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA
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18
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Ngugi SA, Ventura VV, Qazi O, Harding SV, Kitto GB, Estes DM, Dell A, Titball RW, Atkins TP, Brown KA, Hitchen PG, Prior JL. Lipopolysaccharide from Burkholderia thailandensis E264 provides protection in a murine model of melioidosis. Vaccine 2010; 28:7551-5. [PMID: 20837078 DOI: 10.1016/j.vaccine.2010.08.058] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 08/10/2010] [Accepted: 08/11/2010] [Indexed: 11/26/2022]
Abstract
Burkholderia thailandensis is a less virulent close relative of Burkholderia pseudomallei, a CDC category B biothreat agent. We have previously shown that lipopolysaccharide (LPS) extracted from B. pseudomallei can provide protection against a lethal challenge of B. pseudomallei in a mouse model of melioidosis. Sugar analysis on LPS from B. thailandensis strain E264 confirmed that this polysaccharide has a similar structure to LPS from B. pseudomallei. Mice were immunised with LPS from B. thailandensis or B. pseudomallei and challenged with a lethal dose of B. pseudomallei strain K96243. Similar protection levels were observed when either LPS was used as the immunogen. This data suggests that B. thailandensis LPS has the potential to be used as part of a subunit based vaccine against pathogenic B. pseudomallei.
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19
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Michell SL, Dean RE, Eyles JE, Hartley MG, Waters E, Prior JL, Titball RW, Oyston PCF. Deletion of the Bacillus anthracis capB homologue in Francisella tularensis subspecies tularensis generates an attenuated strain that protects mice against virulent tularaemia. J Med Microbiol 2010; 59:1275-1284. [PMID: 20651039 DOI: 10.1099/jmm.0.018911-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
As there is currently no licensed vaccine against Francisella tularensis, the causative agent of tularaemia, the bacterium is an agent of concern as a potential bioweapon. Although F. tularensis has a low infectious dose and high associated mortality, it possesses few classical virulence factors. An analysis of the F. tularensis subspecies tularensis genome sequence has revealed the presence of a region containing genes with low sequence homology to part of the capBCADE operon of Bacillus anthracis. We have generated an isogenic capB mutant of F. tularensis subspecies tularensis SchuS4 and shown it to be attenuated. Furthermore, using BALB/c mice, we have demonstrated that this capB strain affords protection against significant homologous challenge with the wild-type strain. These data have important implications for the development of a defined and efficacious tularaemia vaccine.
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Affiliation(s)
- Stephen L Michell
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Rachel E Dean
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Jim E Eyles
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Margaret Gill Hartley
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Emma Waters
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Joann L Prior
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Richard W Titball
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Petra C F Oyston
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
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20
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Qazi O, Prior JL, Judy BM, Whitlock GC, Kitto GB, Torres AG, Estes DM, Brown KA. Sero-characterization of lipopolysaccharide from Burkholderia thailandensis. Trans R Soc Trop Med Hyg 2009; 102 Suppl 1:S58-60. [PMID: 19121690 DOI: 10.1016/s0035-9203(08)70016-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
We report the successful purification of lipopolysaccharide (LPS) from Burkholderia thailandensis, a Gram-negative bacterium, closely related to the highly pathogenic organisms B. pseudomallei and B. mallei. Burkholderia thailandensis LPS is shown to cross-react with rabbit and mouse sera obtained from inoculation with B. pseudomallei or B. mallei, respectively. These data suggest that B. thailandensis LPS shares similar structural features with LPS molecules from highly pathogenic Burkholderia species. This information may prove useful in ongoing efforts to develop novel vaccines and/or diagnostic reagents.
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Affiliation(s)
- Omar Qazi
- Department of Pediatrics and the Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA
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21
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Eyles JE, Unal B, Hartley MG, Newstead SL, Flick-Smith H, Prior JL, Oyston PCF, Randall A, Mu Y, Hirst S, Molina DM, Davies DH, Milne T, Griffin KF, Baldi P, Titball RW, Felgner PL. Immunodominant Francisella tularensis antigens identified using proteome microarray. Proteomics 2007; 7:2172-83. [PMID: 17533643 DOI: 10.1002/pmic.200600985] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [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: 11/08/2022]
Abstract
Stimulation of protective immune responses against intracellular pathogens is difficult to achieve using non-replicating vaccines. BALB/c mice immunized by intramuscular injection with killed Francisella tularensis (live vaccine strain) adjuvanted with preformed immune stimulating complexes admixed with CpG, were protected when systemically challenged with a highly virulent strain of F. tularensis (Schu S4). Serum from immunized mice was used to probe a whole proteome microarray in order to identify immunodominant antigens. Eleven out of the top 12 immunodominant antigens have been previously described as immunoreactive in F. tularensis. However, 31 previously unreported immunoreactive antigens were revealed using this approach. Twenty four (50%) of the ORFs on the immunodominant hit list belonged to the category of surface or membrane associated proteins compared to only 22% of the entire proteome. There were eight hypothetical protein hits and eight hits from proteins associated with different aspects of metabolism. The chip also allowed us to readily determine the IgG subclass bias, towards individual or multiple antigens, in protected and unprotected animals. These data give insight into the protective immune response and have potentially important implications for the rational design of non-living vaccines for tularemia and other intracellular pathogens.
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Affiliation(s)
- Jim E Eyles
- Defence Science and Technology Laboratory, Porton Down, Salisbury, UK.
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22
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Thomas RM, Titball RW, Oyston PCF, Griffin K, Waters E, Hitchen PG, Michell SL, Grice ID, Wilson JC, Prior JL. The immunologically distinct O antigens from Francisella tularensis subspecies tularensis and Francisella novicida are both virulence determinants and protective antigens. Infect Immun 2006; 75:371-8. [PMID: 17074846 PMCID: PMC1828428 DOI: 10.1128/iai.01241-06] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [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
We have determined the sequence of the gene cluster encoding the O antigen in Francisella novicida and compared it to the previously reported O-antigen cluster in Francisella tularensis subsp. tularensis. Immunization with purified lipopolysaccharide (LPS) from F. tularensis subsp. tularensis or F. novicida protected against challenge with Francisella tularensis subsp. holarctica and F. novicida, respectively. The LPS from F. tularensis subsp. tularensis did not confer protection against challenge with F. novicida, and the LPS from F. novicida did not confer protection against challenge with F. tularensis subsp. holarctica. Allelic replacement mutants of F. tularensis subsp. tularensis or F. novicida which failed to produce O antigen were attenuated, but exposure to these mutants did not induce a protective immune response. The O antigen of F. tularensis subsp. tularensis appeared to be important for intracellular survival whereas the O antigen of F. novicida appeared to be critical for serum resistance and less important for intracellular survival.
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Affiliation(s)
- Rebecca M Thomas
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire, SP4 0JQ, United Kingdom.
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23
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Nelson M, Prior JL, Lever MS, Jones HE, Atkins TP, Titball RW. Evaluation of lipopolysaccharide and capsular polysaccharide as subunit vaccines against experimental melioidosis. J Med Microbiol 2004; 53:1177-1182. [PMID: 15585494 DOI: 10.1099/jmm.0.45766-0] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [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: 11/18/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, which is a major cause of morbidity and mortality in endemic regions. Currently there is no human vaccine against melioidosis. In this study, LPS or capsular polysaccharide was used to immunize BALB/c mice. The different polysaccharide antigens induced antibody responses. Mice vaccinated with LPS developed predominantly IgM and IgG3 responses. Contrastingly, mice vaccinated with capsular polysaccharide developed a predominantly IgG2b response. After immunization, mice were challenged by the intra-peritoneal route and an increased mean time to death was observed compared with unvaccinated controls. Immunization with LPS provided an optimal protective response. Mice challenged by the aerosol route showed a small increase in the mean time to death compared with the unvaccinated controls. The passive transfer of antigen from immunized into naïve mice provided protection against a subsequent challenge. This study is the first time antigens protective by active immunization have been identified and suggests that polysaccharides have potential as vaccine candidates against melioidosis.
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Affiliation(s)
- Michelle Nelson
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Joann L Prior
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - M Stephen Lever
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Helen E Jones
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Timothy P Atkins
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
| | - Richard W Titball
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ, UK
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24
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Prior JL, Prior RG, Hitchen PG, Diaper H, Griffin KF, Morris HR, Dell A, Titball RW. Characterization of the O antigen gene cluster and structural analysis of the O antigen of Francisella tularensis subsp. tularensis. J Med Microbiol 2003; 52:845-851. [PMID: 12972577 DOI: 10.1099/jmm.0.05184-0] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [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: 11/18/2022] Open
Abstract
A gene cluster encoding enzymes involved in LPS O antigen biosynthesis was identified from the partial genome sequence of Francisella tularensis subsp. tularensis Schu S4. All of the genes within the cluster were assigned putative functions based on sequence similarity with genes from O antigen biosynthetic clusters from other bacteria. Ten pairs of overlapping primers were designed to amplify the O antigen biosynthetic cluster by PCR from nine strains of F. tularensis. Although the gene cluster was present in all strains, there was a size difference in one of the PCR products between subsp. tularensis strains and subsp. holarctica strains. LPS was purified from F. tularensis subsp. tularensis Schu S4 and the O antigen was shown by mass spectrometry to have a structure similar to that of F. tularensis subsp. holarctica strain 15. When LPS from F. tularensis subsp. tularensis Schu S4 was used to immunize mice that were then challenged with F. tularensis subsp. tularensis Schu S4, an extended time to death was observed.
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Affiliation(s)
- Joann L Prior
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Richard G Prior
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Paul G Hitchen
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Helen Diaper
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Kate F Griffin
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Howard R Morris
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Anne Dell
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
| | - Richard W Titball
- Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Biological Sciences, Imperial College, London SW7 2AZ, UK 3M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot SL5 7PZ, UK 4Department of Infectious and Tropical Disease, London School of Hygiene and Tropical Medicine, Keppel St., London WC1E 7HT, UK
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25
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Prior JL, Titball RW. Monoclonal antibodies against Yersinia pestis lipopolysaccharide detect bacteria cultured at 28 degrees C or 37 degrees C. Mol Cell Probes 2003; 16:251-6. [PMID: 12270265 DOI: 10.1006/mcpr.2002.0420] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 11/22/2022]
Abstract
Four monoclonal antibodies were generated against Yersinia pestis lipopolysaccharide by immunising mice with a cell surface preparation from Y. pestis strain 1255. In an ELISA the monoclonal antibodies reacted with live whole cells of Y. pestis strain GB cultured at 28 degrees C or 37 degrees C. The lowest detection threshold for Y. pestis strain GB cultured at 28 degrees C was 4 x 10(5) cfu ml(-1) and for bacteria cultured at 37 degrees C was 1 x 10(4) cfu ml(-1). The monoclonal antibodies did not cross react with other pathogenic Yersinia in an ELISA, but showed some cross reactivity in an immuno-blot. The monoclonal antibodies could be used for the detection of Y. pestis cultured at different temperatures and with varying plasmid profiles as the lipopolysaccharide molecule is not temperature regulated and the genes encoding its biosynthesis are located on the bacterial chromosome.
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Affiliation(s)
- J L Prior
- Dstl Chemical and Biological Sciences, Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK.
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26
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Oyston PCF, Prior JL, Kiljunen S, Skurnik M, Hill J, Titball RW. Expression of heterologous O-antigen in Yersinia pestis KIM does not affect virulence by the intravenous route. J Med Microbiol 2003; 52:289-294. [PMID: 12676866 DOI: 10.1099/jmm.0.05044-0] [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: 11/18/2022] Open
Abstract
All strains of Yersinia pestis examined have been found to lack an O-antigen. In other members of the Enterobacteriaceae, the rough phenotype often results in attenuation. However, Y. pestis is the aetiological agent of bubonic plague. In evolving from the ancestral enteropathogenic Yersinia pseudotuberculosis, and with the development of an arthropod-vectored systemic pathogenesis, smooth LPS production is not necessary for Y. pestis virulence and the metabolic burden has been alleviated by inactivation of the O-antigen biosynthetic operon. To investigate this, Y. pestis strain KIM D27 was transformed with a plasmid carrying the operon encoding the O-antigen of Yersinia enterocolitica O : 3. Expression of the O-antigen could be detected in silver-stained gels. The receptor for bacteriophage phiYeO3-12 has been shown to be O-antigen, and infection by this bacteriophage results in lysis of Y. enterocolitica O : 3. Expression of the O-antigen in Y. pestis conferred sensitivity to lysis by phiYeO3-12. The O-antigen-expressing clone was shown to be as virulent in mice by the intravenous route of challenge as the rough wild-type. Assays showed no alteration in the ability of Y. pestis to resist lysis by cationic antimicrobial peptides, serum or polymyxin.
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Affiliation(s)
- P C F Oyston
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
| | - J L Prior
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
| | - S Kiljunen
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
| | - M Skurnik
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
| | - J Hill
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
| | - R W Titball
- Microbiology, DSTL, CBS Porton Down, Salisbury, Wiltshire SP4 0JQ, UK 2Department of Medical Biochemistry and Molecular Biology, Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland
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27
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Hitchen PG, Prior JL, Oyston PCF, Panico M, Wren BW, Titball RW, Morris HR, Dell A. Structural characterization of lipo-oligosaccharide (LOS) from Yersinia pestis: regulation of LOS structure by the PhoPQ system. Mol Microbiol 2002; 44:1637-50. [PMID: 12067350 DOI: 10.1046/j.1365-2958.2002.02990.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [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]
Abstract
The two-component regulatory system PhoPQ has been shown to regulate the expression of virulence factors in a number of bacterial species. For one such virulence factor, lipopolysaccharide (LPS), the PhoPQ system has been shown to regulate structural modifications in Salmonella enterica var Typhimurium. In Yersinia pestis, which expresses lipo-oligosaccharide (LOS), a PhoPQ regulatory system has been identified and an isogenic mutant constructed. To investigate potential modifications to LOS from Y. pestis, which to date has not been fully characterized, purified LOS from wild-type plague and the phoP defective mutant were analysed by mass spectrometry. Here we report the structural characterization of LOS from Y. pestis and the direct comparison of LOS from a phoP mutant. Structural modifications to lipid A, the host signalling portion of LOS, were not detected but analysis of the core revealed the expression of two distinct molecular species in wild-type LOS, differing in terminal galactose or heptose. The phoP mutant was restricted to the expression of a single molecular species, containing terminal heptose. The minimum inhibitory concentration of cationic antimicrobial peptides for the two strains was determined and compared with the wild-type: the phoP mutant was highly sensitive to polymyxin. Thus, LOS modification is under the control of the PhoPQ regulatory system and the ability to alter LOS structure may be required for survival of Y. pestis within the mammalian and/or flea host.
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Affiliation(s)
- Paul G Hitchen
- Department of Biological Sciences, Wolfson Building, Imperial College, London, SW7 2AY, UK
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28
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Prior JL, Parkhill J, Hitchen PG, Mungall KL, Stevens K, Morris HR, Reason AJ, Oyston PC, Dell A, Wren BW, Titball RW. The failure of different strains of Yersinia pestis to produce lipopolysaccharide O-antigen under different growth conditions is due to mutations in the O-antigen gene cluster. FEMS Microbiol Lett 2001; 197:229-33. [PMID: 11313139 DOI: 10.1111/j.1574-6968.2001.tb10608.x] [Citation(s) in RCA: 46] [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: 11/27/2022] Open
Abstract
The lipopolysaccharide (LPS) from eight strains of Yersinia pestis which had been cultured at 28 degrees C appeared to be devoid of an O-antigen when analysed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. LPS isolated from three of these strains which had been cultured at 37 degrees C also appeared to be devoid of an O-antigen. When the LPS from Y. pestis strain CO92 was purified and analysed by matrix-assisted laser desorption-ionisation time-of-flight mass spectrometry, the observed signals were in the mass range predicted for molecules containing lipid A plus the core oligosaccharide but lacking an O-antigen. The nucleotide sequence of Y. pestis strain CO92 revealed the presence of a putative O-antigen gene cluster. However, frame-shift mutations in the ddhB, gmd, fcl and ushA genes are likely to prevent expression of the O-antigen thus explaining the loss of phenotype.
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Affiliation(s)
- J L Prior
- Defence Evaluation and Research Agency, CBD Porton Down, Salisbury, Wiltshire, UK.
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29
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Prior JL, Hitchen PG, Williamson DE, Reason AJ, Morris HR, Dell A, Wren BW, Titball RW. Characterization of the lipopolysaccharide of Yersinia pestis. Microb Pathog 2001; 30:49-57. [PMID: 11162185 DOI: 10.1006/mpat.2000.0411] [Citation(s) in RCA: 44] [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: 11/22/2022]
Abstract
Lipopolysaccharide (LPS) extracted from eight strains of Yersinia pestis, which had been cultured at 28 or 37 degrees C, reacted equally well, in Western blots, with four monoclonal antibodies generated against the LPS from a single strain of Y. pestis cultured at 28 degrees C. LPS was extracted and purified from Y. pestis strain GB, which had been cultured at 28 degrees C. When the LPS was analysed by SDS-PAGE and MALDI-TOF mass spectrometry it was found to be devoid of an O-antigen. The LPS possessed activity of 2.7 endotoxin units/ng in the Limulus amoebocyte lysate assay. The LPS stimulated the production of TNFalpha and IL-6 from mouse macrophages, but was less active in these assays than LPS isolated from Escherichia coli strain 0111. Y. pestis LPS, either alone or with cholera toxin B subunit, was used to immunize mice. Either immunization schedule resulted in the development of an antibody response to LPS. However, this response did not provide protection against 100 MLD of Y. pestis strain GB.
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Affiliation(s)
- J L Prior
- DERA, CBD Porton Down, Salisbury, Wiltshire, SP4 0JQ, UK.
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