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Gallegos-Candela M, Boyer AE, Woolfitt AR, Brumlow J, Lins RC, Quinn CP, Hoffmaster AR, Meister G, Barr JR. Validated MALDI-TOF-MS method for anthrax lethal factor provides early diagnosis and evaluation of therapeutics. Anal Biochem 2017; 543:97-107. [PMID: 29224733 PMCID: PMC7904043 DOI: 10.1016/j.ab.2017.12.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/01/2017] [Accepted: 12/06/2017] [Indexed: 01/12/2023]
Abstract
Anthrax lethal factor (LF) is a zinc-dependent endoprotease and a critical virulence factor for Bacillus anthracis, the causative agent of anthrax. The mass spectrometry (MS) method for total-LF quantification includes three steps; 1) LF specific antibody capture/concentration, 2) LF-specific hydrolysis of a peptide substrate, and 3) detection and quantification of LF-cleaved peptides by isotope-dilution MALDI-TOF/MS. Recombinant LF spiked plasma was used for calibration and quality control (QC) materials. Specificity was 100% from analysis of serum and plasma from 383 non-infected humans, 31 rabbits, and 24 rhesus macaques. Sensitivity was 100% from 32 human clinical anthrax cases including infections by inhalation, ingestion, cutaneous and injection exposures and experimental infections for 29 rabbits and 24 rhesus macaques with inhalation anthrax. Robustness evaluation included sample storage, serum and plasma, antimicrobial and antitoxin effects and long-term performance. Data from 100 independent runs gave detection limits 0.01 ng/mL (111 amol/mL) for the 4-h method and 0.0027 ng/mL (30 amol/mL) for an alternate 20-h method. QC precision ranged from 7.7 to 14.8% coefficient of variation and accuracy from 0.2 to 9.8% error. The validated LF MS method provides sensitive quantification of anthrax total-LF using a robust high throughput platform for early diagnosis and evaluation of therapeutics during an anthrax emergency.
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Affiliation(s)
- Maribel Gallegos-Candela
- Centers for Disease Control and Prevention, 4770 Buford Highway Mailstop F-50, Atlanta, GA 30341, USA
| | - Anne E Boyer
- Centers for Disease Control and Prevention, 4770 Buford Highway Mailstop F-50, Atlanta, GA 30341, USA.
| | - Adrian R Woolfitt
- Centers for Disease Control and Prevention, 4770 Buford Highway Mailstop F-50, Atlanta, GA 30341, USA
| | - Judy Brumlow
- Battelle Atlanta Analytical Services, 2987 Clairmont Road NE, Suite 450, Atlanta, GA 30329, USA
| | - Renato C Lins
- Battelle Atlanta Analytical Services, 2987 Clairmont Road NE, Suite 450, Atlanta, GA 30329, USA
| | - Conrad P Quinn
- Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30329, USA
| | - Alex R Hoffmaster
- Centers for Disease Control and Prevention, 1600 Clifton Road, Atlanta, GA 30329, USA
| | - Gabriel Meister
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Rd, West Jefferson, OH 43162, USA
| | - John R Barr
- Centers for Disease Control and Prevention, 4770 Buford Highway Mailstop F-50, Atlanta, GA 30341, USA
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Sachdeva A, Singh AK, Sharma SK. An electrochemiluminescence assay for the detection of bio threat agents in selected food matrices and in the screening of Clostridium botulinum outbreak strains associated with type A botulism. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:707-712. [PMID: 23873138 DOI: 10.1002/jsfa.6310] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 05/02/2013] [Accepted: 07/19/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND Specific screening methods for complex food matrices are needed that enable unambiguous and sensitive detection of bio threat agents (BTAs) such as Bacillus anthracis spores and microbial toxins (e.g. staphylococcal enterotoxin B (SEB) and clostridial botulinum neurotoxins (BoNTs)). The present study describes an image-based 96-well Meso Scale Discovery (MSD) electrochemiluminescence (ECL) assay for simultaneous detection of BTAs in dairy milk products. RESULTS The limit of detection of this ECL assay is 40 pg mL⁻¹ for BoNT/A complex, 10 pg mL⁻¹ for SEB and 40000 CFU mL⁻¹ for Bacillus anthracis spores in dairy milk products. The ECL assay was successfully applied to screen type A Clostridium botulinum outbreak strains. CONCLUSION The results of the study indicate that this ECL assay is very sensitive, rapid (<6 h) and multiplex in nature. The ECL assay has potential for use as an in vitro screening method for BTAs over other comparable immunoassays.
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Affiliation(s)
- Amita Sachdeva
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 5100 Paint Branch Parkway, College Park, MD, 20740, USA
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Distinguishing Tropical Infectious Diseases from Bioterrorism. TROPICAL INFECTIOUS DISEASES: PRINCIPLES, PATHOGENS AND PRACTICE 2011. [PMCID: PMC7150159 DOI: 10.1016/b978-0-7020-3935-5.00125-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Säbel CE, St-Denis S, Neureuther JM, Carbone R, Siemann S. Alkaline earth metals are not required for the restoration of the apoform of anthrax lethal factor to its holoenzyme state. Biochem Biophys Res Commun 2010; 403:209-13. [PMID: 21059339 DOI: 10.1016/j.bbrc.2010.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022]
Abstract
Anthrax lethal factor (LF) is a zinc-dependent metalloendopeptidase previously shown to require calcium and magnesium for the restoration of its catalytic function upon exposure of the apoprotein (apoLF) to Zn(2+). Since concrete Ca(2+)/Mg(2+) binding sites have not been identified in LF, the effects of alkaline earth metals on the enzymatic function of holoLF (ZnLF) and on the reconstitution of apoLF were reinvestigated. The current study reveals alkaline earth metals to be inhibitory at concentrations higher than 1mM. A combination of activity/inhibition assays and Tb(3+) luminescence spectroscopy was employed to unequivocally establish the presence of at least one inhibitory low-affinity Ca(2+)-site in LF. A comparative analysis of apoLF preparations obtained by dialysis and centrifugal filtration (following treatment of ZnLF with chelators) revealed the exposure of apoLF to low equimolar amounts of Zn(2+) to be sufficient for the full restoration of the protein's catalytic competence, a finding constistent with the picomolar dissociation constant of ZnLF determined in this study. The previously documented requirement of Ca(2+) and Mg(2+) in apoLF reconstitution may be explicable on the basis of contamination of dialyzed apoprotein preparations with residual chelator, a phenomenon not encountered with apoLF obtained by centrifugal filtration.
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Affiliation(s)
- Crystal E Säbel
- Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Rd., Sudbury, Ontario, Canada P3E 2C6
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Yang X, Yuan R, Chai Y, Zhuo Y, Mao L, Yuan S. Ru(bpy)3(2+)-doped silica nanoparticles labeling for a sandwich-type electrochemiluminescence immunosensor. Biosens Bioelectron 2009; 25:1851-5. [PMID: 20074928 DOI: 10.1016/j.bios.2009.12.027] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2009] [Revised: 12/07/2009] [Accepted: 12/21/2009] [Indexed: 02/09/2023]
Abstract
A new approach was established to construct a sandwich-type electrochemiluminescence (ECL) immunosensor by using Ru(bpy)(3)(2+)-doped silica (abbreviated as Ru-SiO(2)) nanoparticles to label secondary antibody. Firstly, carboxylate-terminated multi-walled carbon nanotubes (MWCNTs) were modified on the electrode to bond with avidin. Subsequently, biotinylated antibodies were immobilized on the surface of the electrode by employing the specific interaction of biotin/avidin and the non-covalent and covalent conjugation function of MWCNTs. Later, the electrode was incubated with antigen of mouse IgG and then reacted with the secondary antibody which was labeled by Ru-SiO(2). Accordingly, through the ECL response of Ru-SiO(2) and tripropylamine (TPA), a strong ECL signal was obtained and an amplification analysis of protein interaction was achieved. The present immunosensor showed a wide linear range of 0.05-200.00 ng mL(-1) for detecting mouse IgG, with a low detection limit of 17 pg mL(-1). There was a 4-300-fold improvement in detection limit compared with other similar studies. The morphologies of Ru-SiO(2) nanoparticles were characterized by using transmission electronic microscopy (TEM). The fabrication process of the immunosensor was studied by cyclic voltammetry (CV) and the performance of the immunosensor was monitored with an electrochemiluminescence analyzer. This new strategy for preparation of the ECL immunosensor could be easily realized and has potential application in ultrasensitive bioassays.
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Affiliation(s)
- Xia Yang
- Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
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Kim J, Yoon MY. ANTHRAX LETHAL FACTOR: CRITICAL VIRULENCE FACTOR OF PATHOGENESIS OF ANTHRAX TOXINS. TOXIN REV 2008. [DOI: 10.1080/15569540500320987] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hudson MJ, Beyer W, Böhm R, Fasanella A, Garofolo G, Golinski R, Goossens PL, Hahn U, Hallis B, King A, Mock M, Montecucco C, Ozin A, Tonello F, Kaufmann SH. Bacillus anthracis: balancing innocent research with dual-use potential. Int J Med Microbiol 2008; 298:345-64. [PMID: 18375178 PMCID: PMC7106442 DOI: 10.1016/j.ijmm.2007.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 09/21/2007] [Accepted: 09/28/2007] [Indexed: 12/30/2022] Open
Abstract
Anthrax Euronet, a Coordination Action of the EU 6th Framework Programme, was designed to strengthen networking activities between anthrax research groups in Europe and to harmonise protocols for testing anthrax vaccines and therapeutics. Inevitably, the project also addressed aspects of the current political issues of biosecurity and dual-use research, i.e. research into agents of important diseases of man, livestock or agriculture that could be used as agents of bioterrorism. This review provides a comprehensive overview of the biology of Bacillus anthracis, of the pathogenesis, epidemiology and diagnosis of anthrax, as well as vaccine and therapeutic intervention strategies. The proposed requirement for a code of conduct for working with dual-use agents such as the anthrax bacillus is also discussed.
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Affiliation(s)
| | | | | | - Antonio Fasanella
- Istituto Zooprofilattico Sperimentale of Puglia and Basilicata, Foggia, Italy
| | - Giuliano Garofolo
- Istituto Zooprofilattico Sperimentale of Puglia and Basilicata, Foggia, Italy
| | - Robert Golinski
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
| | | | | | - Bassam Hallis
- Health Protection Agency, Porton Down, Salisbury, UK
| | | | | | | | - Amanda Ozin
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
| | | | - Stefan H.E. Kaufmann
- Department of Immunology, Max Planck Institute for Infection Biology, Charitéplatz 1, D-10117 Berlin, Germany
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Quantitative electrochemiluminescence detection of proteins: Avidin-based sensor and tris(2,2'-bipyridine) ruthenium(II) label. Biosens Bioelectron 2008; 23:1645-51. [PMID: 18337079 DOI: 10.1016/j.bios.2008.01.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2007] [Revised: 12/19/2007] [Accepted: 01/29/2008] [Indexed: 10/22/2022]
Abstract
Quantitative electrochemiluminescence (ECL) detection of a model protein, bovine serum albumin (BSA) was achieved via biotin-avidin interaction using an avidin-based sensor and a well-developed ECL system of tris(2,2'-bipyridine) ruthenium(II) derivative as label and tri-n-propylamine (TPA) as coreactant. To detect the protein, avidin was linked to the glassy carbon electrode through passive adsorptions and covalent interaction with carboxylate-terminated carbon nanotubes that was used as binder to immobilize avidin onto the electrode. Then, biotinylated BSA tagged with tris(2,2'-bipyridine) ruthenium(II) label was attached to the prepared avidin surface. After binding of BSA labeled with tris(2,2'-bipyridine) ruthenium(II) derivative to the surface-immobilized avidin through biotin, ECL response was generated when the self-assembled modified electrode was immersed in a TPA-containing electrolyte solution. Such double protein labeling protocol with a biotin label for biorecognition and ruthenium label for ECL detection facilitated the detection of protein compared to the classical double antibody sandwich format. The ECL intensity was linearly proportional to the feed concentration of BSA over two orders of magnitude in the range of 15nM to 7.5microM. The detection limit was estimated to be 1.5nM. Further application to the lysozyme analysis was carried out to validate the present approach for an effective and favorable protocol for the quantitative detection of proteins. The dynamic range of lysozyme was from 0.001gL(-1) to 0.1gL(-1) and the detection limit was 0.1mgL(-1). Electrochemical impedance and cyclic voltammetric measurements along with some necessary control experiments were conducted to characterize the successful formation of self-assembled modified electrodes and to grant the whole detection process.
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Merrill GA, Rivera VR, Neal DD, Young C, Poli MA. A quantitative electrochemiluminescence assay for Clostridium perfringens alpha toxin. Anal Biochem 2006; 357:181-7. [PMID: 16949539 DOI: 10.1016/j.ab.2006.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Revised: 07/11/2006] [Accepted: 07/17/2006] [Indexed: 11/20/2022]
Abstract
Described is a rapid direct sandwich format electrochemiluminescence assay for identifying and assaying Clostridium perfringens alpha toxin. Biotinylated antibodies to C. perfringens alpha toxin bound to streptavidin paramagnetic beads specifically immunoadsorbed soluble sample alpha toxin which subsequently selectively immunoadsorbed ruthenium (Ru)-labeled detection antibodies. The ruthenium chelate of detection antibodies chemically reacted in the presence of tripropylamine and upon electronic stimulation emitted photons (electrochemiluminescence) that were detected by the photodiode of the detector. Elevated toxin concentrations increased toxin immunoadsorption and the specific immunoadsorption of Ru-labeled antibodies to alpha toxin, which resulted in increased dose-dependent electrochemiluminescent signals. The standardized assay was rapid (single 2.5-h coincubation of all reagents), required no wash steps, and had a sensitivity of about 1 ng/ml of toxin. The assay had excellent accuracy and precision and was validated in buffer, serum, and urine with no apparent matrix effects.
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Affiliation(s)
- Gerald A Merrill
- Department of Clinical Investigation, Brooke Army Medical Center, 3400 Rawley E. Chambers Ave, STE A, Ft. Sam Houston, TX 78234-6315, USA.
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Distinguishing Tropical Infectious Diseases from Bioterrorism. TROPICAL INFECTIOUS DISEASES 2006. [PMCID: PMC7152372 DOI: 10.1016/b978-0-443-06668-9.50124-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Saunders MJ, Kim H, Woods TA, Nolan JP, Sklar LA, Edwards BS, Graves SW. Microsphere-based protease assays and screening application for lethal factor and factor Xa. Cytometry A 2006; 69:342-52. [PMID: 16604538 DOI: 10.1002/cyto.a.20268] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Proteases regulate many biological pathways in humans and are components of several bacterial toxins. Protease studies and development of protease inhibitors do not follow a single established methodology and are mostly protease specific. METHODS We have created recombinant fusion proteins consisting of a biotinylated attachment sequence linked to a GFP via a protease cleavage site to develop a multiplexable microsphere-based protease assay system. Using the proteases lethal factor and factor Xa, we performed kinetic experiments to determine optimal conditions for inhibitor screens and detect known inhibitors using the HyperCyt flow cytometry system. RESULTS We have demonstrated specific cleavage of lethal factor and factor Xa substrates, optimized screening conditions for these substrates, shown specific inhibition of the proteases, and demonstrated high throughput detection of these inhibitors. CONCLUSIONS The assay developed here is adaptable to any site-specific protease, compatible with high throughput flow cytometry systems, and multiplexable. Coupled with flow cytometry, which provides continuous time resolution and intrinsic resolution of free vs. bound fluorophores, this assay will be useful for high throughput screening of protease inhibitors in general and could simplify assays designed to determine protease mechanism.
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Affiliation(s)
- Matthew J Saunders
- National Flow Cytometry Resource, Biosciences Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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Kim J, Choi MK, Koo BS, Yoon MY. Development of high-throughput assay of lethal factor using native substrate. Anal Biochem 2005; 341:33-9. [PMID: 15866525 DOI: 10.1016/j.ab.2005.03.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2004] [Indexed: 11/22/2022]
Abstract
The design of inhibitors for anthrax lethal factor (LF) is currently of interest as an approach for the treatment of anthrax because LF plays a major role in the cytotoxicity of target cells. LF is a zinc-dependent metalloprotease that specifically cleaves the mitogen-activated protein kinase kinase (MKK) family. Current assay systems for the screening of LF inhibitor use the optimized synthetic peptide coupled with various kinds of fluorophores, enabling fast, sensitive, and robust assays suited to high-throughput screening. However, evidence suggests that the regions beside the cleavage site are also involved in specificity and proteolytic activity of LF. In the current study, we tried to develop a high-throughput assay for LF activity based on native substrate, mitogen-activated ERK kinase 1 (MEK1). The assay system relies on the enhanced chemiluminescence signal resulting from a specific antibody against the C-terminal region of native substrate. A glutathione-coated multiwell plate was used as a solid support to immobilize the native substrate by its N-terminal glutathione-S-transferase moiety. Immobilized substrate increases the specificity and sensitivity of LF-catalyzed substrate hydrolysis compared with the solution phase assay. This assay system might be used to discover a wide spectrum of anthrax inhibitors.
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Affiliation(s)
- Joungmok Kim
- Department of Chemistry, College of Natural Science, Hanyang University, Seoul 133-791, Republic of Korea
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Barth H, Aktories K, Popoff MR, Stiles BG. Binary bacterial toxins: biochemistry, biology, and applications of common Clostridium and Bacillus proteins. Microbiol Mol Biol Rev 2004; 68:373-402, table of contents. [PMID: 15353562 PMCID: PMC515256 DOI: 10.1128/mmbr.68.3.373-402.2004] [Citation(s) in RCA: 285] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic "A-B" paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The "B" components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated "B" components form homoheptameric rings that subsequently dock with an "A" component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, "A" molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria.
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Affiliation(s)
- Holger Barth
- Institut für Experimentelle und Klinische Pharmakologie und Toxikologie der Albert-Ludwigs-Universität Freiburg, Otto-Krayer-Haus, Albertstrasse 25, D-79104 Freiburg, Germany.
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Bead injection with a simple flow-injection system: an economical alternative for trace analysis. Trends Analyt Chem 2004. [DOI: 10.1016/j.trac.2004.06.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Cordoba-Rodriguez R, Fang H, Lankford CSR, Frucht DM. Anthrax lethal toxin rapidly activates caspase-1/ICE and induces extracellular release of interleukin (IL)-1beta and IL-18. J Biol Chem 2004; 279:20563-6. [PMID: 15010463 DOI: 10.1074/jbc.c300539200] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Anthrax lethal toxin (LT), a critical virulence factor for Bacillus anthracis, has been demonstrated to cleave and to inactivate mitogen-activated protein kinase kinases (MAPKKs) that propagate prosurvival signals in macrophages (1-5). Whether this action of anthrax LT leads to the production of proinflammatory cytokines by macrophages has been more controversial (6, 7). We now report that anthrax LT treatment leads to the specific extracellular release of interleukin (IL)-1beta and IL-18 by the murine macrophage cell lines, RAW264.7 and J774A.1. Studies of the processing of IL-1beta reveal that the levels of activated/cleaved IL-1beta in RAW264.7 and J774.A1 cells are increased following treatment with anthrax LT. Enhanced processing of IL-1beta directly correlates with increased levels in the activation of its upstream regulator, IL-1beta-converting enzyme/Caspase-1 (ICE). The extracellular release of IL-1beta and IL-18 in response to anthrax LT is ICE-dependent, as an ICE-specific inhibitor blocks this process. These data indicate that ICE, IL-1beta, and IL-18 are downstream effectors of anthrax LT in macrophages, providing the basis for new bioassays for anthrax LT activity and representing potential therapeutic targets.
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Affiliation(s)
- Ruth Cordoba-Rodriguez
- Division of Monoclonal Antibodies, Office of Biotechnology Products, Office of Pharmaceutical Science, Center for Drug Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
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