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Lin GL, Chang HH, Lin WT, Liou YS, Lai YL, Hsieh MH, Chen PK, Liao CY, Tsai CC, Wang TF, Chu SC, Kau JH, Huang HH, Hsu HL, Sun DS. Dachshund Homolog 1: Unveiling Its Potential Role in Megakaryopoiesis and Bacillus anthracis Lethal Toxin-Induced Thrombocytopenia. Int J Mol Sci 2024; 25:3102. [PMID: 38542074 PMCID: PMC10970148 DOI: 10.3390/ijms25063102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 04/04/2024] Open
Abstract
Lethal toxin (LT) is the critical virulence factor of Bacillus anthracis, the causative agent of anthrax. One common symptom observed in patients with anthrax is thrombocytopenia, which has also been observed in mice injected with LT. Our previous study demonstrated that LT induces thrombocytopenia by suppressing megakaryopoiesis, but the precise molecular mechanisms behind this phenomenon remain unknown. In this study, we utilized 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced megakaryocytic differentiation in human erythroleukemia (HEL) cells to identify genes involved in LT-induced megakaryocytic suppression. Through cDNA microarray analysis, we identified Dachshund homolog 1 (DACH1) as a gene that was upregulated upon TPA treatment but downregulated in the presence of TPA and LT, purified from the culture supernatants of B. anthracis. To investigate the function of DACH1 in megakaryocytic differentiation, we employed short hairpin RNA technology to knock down DACH1 expression in HEL cells and assessed its effect on differentiation. Our data revealed that the knockdown of DACH1 expression suppressed megakaryocytic differentiation, particularly in polyploidization. We demonstrated that one mechanism by which B. anthracis LT induces suppression of polyploidization in HEL cells is through the cleavage of MEK1/2. This cleavage results in the downregulation of the ERK signaling pathway, thereby suppressing DACH1 gene expression and inhibiting polyploidization. Additionally, we found that known megakaryopoiesis-related genes, such as FOSB, ZFP36L1, RUNX1, FLI1, AHR, and GFI1B genes may be positively regulated by DACH1. Furthermore, we observed an upregulation of DACH1 during in vitro differentiation of CD34-megakaryocytes and downregulation of DACH1 in patients with thrombocytopenia. In summary, our findings shed light on one of the molecular mechanisms behind LT-induced thrombocytopenia and unveil a previously unknown role for DACH1 in megakaryopoiesis.
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Affiliation(s)
- Guan-Ling Lin
- Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan; (G.-L.L.); (H.-H.C.); (P.-K.C.)
- Integration Center of Traditional Chinese and Modern Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Hsin-Hou Chang
- Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan; (G.-L.L.); (H.-H.C.); (P.-K.C.)
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Wei-Ting Lin
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Yu-Shan Liou
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Yi-Ling Lai
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Min-Hua Hsieh
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
| | - Po-Kong Chen
- Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan; (G.-L.L.); (H.-H.C.); (P.-K.C.)
| | - Chi-Yuan Liao
- Department of Obstetrics and Gynecology, Mennonite Christian Hospital, Hualien 97004, Taiwan; (C.-Y.L.); (C.-C.T.)
| | - Chi-Chih Tsai
- Department of Obstetrics and Gynecology, Mennonite Christian Hospital, Hualien 97004, Taiwan; (C.-Y.L.); (C.-C.T.)
| | - Tso-Fu Wang
- Department of Hematology and Oncology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan; (T.-F.W.); (S.-C.C.)
- Department of Medicine, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Buddhist Tzu Chi Stem Cells Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan
| | - Sung-Chao Chu
- Department of Hematology and Oncology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan; (T.-F.W.); (S.-C.C.)
- Department of Medicine, College of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Buddhist Tzu Chi Stem Cells Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97004, Taiwan
| | - Jyh-Hwa Kau
- Institute of Preventive Medicine, National Defense Medical Center, Taipei 11490, Taiwan; (J.-H.K.); (H.-H.H.); (H.-L.H.)
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei 11490, Taiwan; (J.-H.K.); (H.-H.H.); (H.-L.H.)
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei 11490, Taiwan; (J.-H.K.); (H.-H.H.); (H.-L.H.)
| | - Der-Shan Sun
- Institute of Medical Sciences, Tzu Chi University, Hualien 97004, Taiwan; (G.-L.L.); (H.-H.C.); (P.-K.C.)
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien 97004, Taiwan; (W.-T.L.); (Y.-S.L.); (Y.-L.L.); (M.-H.H.)
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Boening-Ulman KM, Mikelonis AM, Heckman JL, Calfee MW, Ratliff K, Youn S, Smith JS, Mitchell CE, Hunt WF, Winston RJ. The potential to manage releases of Bacillus anthracis using bioretention and a high flow media filter: Results of simulated runoff testing with tracer spores Bacillus globigii. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 354:120286. [PMID: 38354613 DOI: 10.1016/j.jenvman.2024.120286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/19/2024] [Accepted: 02/02/2024] [Indexed: 02/16/2024]
Abstract
The threat of bioterrorism has spurred research on the decontamination and containment of different agents. Anthrax [causative agent Bacillus anthracis (Ba)] is a disease that can lead to severe infections within human and animals, particularly when inhaled. This research investigated the use of spore-contaminated simulated runoff events into stormwater control measures (SCMs), which are designed to retain and improve the quality of runoff and may have the potential to filter and contain the spores. In this study, the effectiveness of a bioretention cell (BRC) and high flow media filter (HFMF) in Huron, Ohio, were evaluated for removal of Bacillus globigii (Bg) spores (a harmless cognate of Ba). Three 4-8 mm simulated runoff events were created for each SCM using a fire hydrant and Bg spores were injected into the runoff upstream of the SCM inlets. The BRC significantly (p < 0.001) outperformed the HFMF in reducing Bg concentrations and loads, with an average load reduction of 1.9 log (∼99% reduction) compared to 0.4 (∼60% reduction), respectively. A probable critical design factor leading to these differences was the infiltration rate of the media and subsequent retention time within the filters, which was supported by similar disparities in suspended solids reductions. Differences in spore removal may also have been due to particle size distribution of the HFMF, which was more gravelly than the bioretention cell. At 3 and 6 months after the-simulated runoff tests, soil samples taken from both SCMs, yielding detectable Bg spores within the top 15 cm of media, with increased spore concentrations where ponding occurred for longer durations during the tests. This suggests that forebays and areas near inlets may be hotspots for spore cleanup in a real-world bioterrorism incident.
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Affiliation(s)
- Kathryn M Boening-Ulman
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Dr., Columbus, OH, 43210, USA.
| | - Anne M Mikelonis
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Solutions and Emergency Response, 109 T.W. Alexander Dr., Research Triangle Park, NC, 27711, USA
| | - J Lee Heckman
- APTIM Government Solutions, 1600 Gest St., U.S. Environmental Protection Agency Test and Evaluation Facility, Cincinnati, OH, 45204, USA
| | - M Worth Calfee
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Solutions and Emergency Response, 109 T.W. Alexander Dr., Research Triangle Park, NC, 27711, USA
| | - Katherine Ratliff
- U.S. Environmental Protection Agency, Office of Research and Development, Center for Environmental Solutions and Emergency Response, 109 T.W. Alexander Dr., Research Triangle Park, NC, 27711, USA
| | - Sungmin Youn
- Department of Civil Engineering, Marshall University, Huntington, WV, 25755, USA
| | - Joseph S Smith
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Dr., Columbus, OH, 43210, USA
| | - Caleb E Mitchell
- Department of Biological and Agricultural Engineering, North Carolina State University, 3100 Faucette Dr., Raleigh, NC, 27695, USA
| | - William F Hunt
- Department of Biological and Agricultural Engineering, North Carolina State University, 3100 Faucette Dr., Raleigh, NC, 27695, USA
| | - Ryan J Winston
- Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Dr., Columbus, OH, 43210, USA; Department of Civil, Environmental and Geodetic Engineering, The Ohio State University, 2070 Neil Ave., Columbus, OH, 43210, USA
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Liu A, Zhang H, Zheng Q, Wang S. The Potential of Cyclodextrins as Inhibitors for the BM2 Protein: An In Silico Investigation. Molecules 2024; 29:620. [PMID: 38338365 PMCID: PMC10856705 DOI: 10.3390/molecules29030620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 02/12/2024] Open
Abstract
The influenza BM2 transmembrane domain (BM2TM), an acid-activated proton channel, is an attractive antiviral target due to its essential roles during influenza virus replication, whereas no effective inhibitors have been reported for BM2. In this study, we draw inspiration from the properties of cyclodextrins (CDs) and hypothesize that CDs of appropriate sizes may possess the potential to act as inhibitors of the BM2TM proton channel. To explore this possibility, molecular dynamics simulations were employed to assess their inhibitory capabilities. Our findings reveal that CD4, CD5, and CD6 are capable of binding to the BM2TM proton channel, resulting in disrupted water networks and reduced hydrogen bond occupancy between H19 and the solvent within the BM2TM channel necessary for proton conduction. Notably, CD4 completely obstructs the BM2TM water channel. Based on these observations, we propose that CD4, CD5, and CD6 individually contribute to diminishing the proton transfer efficiency of the BM2 protein, and CD4 demonstrates promising potential as an inhibitor for the BM2 proton channel.
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Affiliation(s)
- Aijun Liu
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China; (A.L.); (H.Z.)
| | - Hao Zhang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China; (A.L.); (H.Z.)
| | - Qingchuan Zheng
- School of Pharmaceutical Sciences, Jilin University, Changchun, 130021, China
| | - Song Wang
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China; (A.L.); (H.Z.)
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Goossens PL. Bacillus anthracis, "la maladie du charbon", Toxins, and Institut Pasteur. Toxins (Basel) 2024; 16:66. [PMID: 38393144 PMCID: PMC10891547 DOI: 10.3390/toxins16020066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/25/2023] [Accepted: 12/30/2023] [Indexed: 02/25/2024] Open
Abstract
Institut Pasteur and Bacillus anthracis have enjoyed a relationship lasting almost 120 years, starting from its foundation and the pioneering work of Louis Pasteur in the nascent fields of microbiology and vaccination, and blooming after 1986 following the molecular biology/genetic revolution. This contribution will give a historical overview of these two research eras, taking advantage of the archives conserved at Institut Pasteur. The first era mainly focused on the production, characterisation, surveillance and improvement of veterinary anthrax vaccines; the concepts and technologies with which to reach a deep understanding of this research field were not yet available. The second period saw a new era of B. anthracis research at Institut Pasteur, with the anthrax laboratory developing a multi-disciplinary approach, ranging from structural analysis, biochemistry, genetic expression, and regulation to bacterial-host cell interactions, in vivo pathogenicity, and therapy development; this led to the comprehensive unravelling of many facets of this toxi-infection. B. anthracis may exemplify some general points on how science is performed in a given society at a given time and how a scientific research domain evolves. A striking illustration can be seen in the additive layers of regulations that were implemented from the beginning of the 21st century and their impact on B. anthracis research. B. anthracis and anthrax are complex systems that raise many valuable questions regarding basic research. One may hope that B. anthracis research will be re-initiated under favourable circumstances later at Institut Pasteur.
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Biggel M, Jessberger N, Kovac J, Johler S. Recent paradigm shifts in the perception of the role of Bacillus thuringiensis in foodborne disease. Food Microbiol 2022; 105:104025. [DOI: 10.1016/j.fm.2022.104025] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/10/2022] [Accepted: 03/11/2022] [Indexed: 12/16/2022]
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Osterloh A. Vaccination against Bacterial Infections: Challenges, Progress, and New Approaches with a Focus on Intracellular Bacteria. Vaccines (Basel) 2022; 10:vaccines10050751. [PMID: 35632507 PMCID: PMC9144739 DOI: 10.3390/vaccines10050751] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/08/2022] [Accepted: 05/09/2022] [Indexed: 12/13/2022] Open
Abstract
Many bacterial infections are major health problems worldwide, and treatment of many of these infectious diseases is becoming increasingly difficult due to the development of antibiotic resistance, which is a major threat. Prophylactic vaccines against these bacterial pathogens are urgently needed. This is also true for bacterial infections that are still neglected, even though they affect a large part of the world’s population, especially under poor hygienic conditions. One example is typhus, a life-threatening disease also known as “war plague” caused by Rickettsia prowazekii, which could potentially come back in a war situation such as the one in Ukraine. However, vaccination against bacterial infections is a challenge. In general, bacteria are much more complex organisms than viruses and as such are more difficult targets. Unlike comparatively simple viruses, bacteria possess a variety of antigens whose immunogenic potential is often unknown, and it is unclear which antigen can elicit a protective and long-lasting immune response. Several vaccines against extracellular bacteria have been developed in the past and are still used successfully today, e.g., vaccines against tetanus, pertussis, and diphtheria. However, while induction of antibody production is usually sufficient for protection against extracellular bacteria, vaccination against intracellular bacteria is much more difficult because effective defense against these pathogens requires T cell-mediated responses, particularly the activation of cytotoxic CD8+ T cells. These responses are usually not efficiently elicited by immunization with non-living whole cell antigens or subunit vaccines, so that other antigen delivery strategies are required. This review provides an overview of existing antibacterial vaccines and novel approaches to vaccination with a focus on immunization against intracellular bacteria.
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Affiliation(s)
- Anke Osterloh
- Department of Infection Immunology, Research Center Borstel, Parkallee 22, 23845 Borstel, Germany
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7
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Transcriptional Regulators in Bacillus anthracis: A Potent Biothreat Agent. RECENT DEVELOPMENTS IN MICROBIAL TECHNOLOGIES 2021. [DOI: 10.1007/978-981-15-4439-2_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Lawrence WS, Peel JE, Sivasubramani SK, Baze WB, Whorton EB, Beasley DWC, Comer JE, Hughes DE, Ling LL, Peterson JW. Teixobactin Provides Protection against Inhalation Anthrax in the Rabbit Model. Pathogens 2020; 9:pathogens9090773. [PMID: 32971758 PMCID: PMC7558628 DOI: 10.3390/pathogens9090773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 01/20/2023] Open
Abstract
The use of antibiotics is a vital means of treating infections caused by the bacteria Bacillus (B.) anthracis. Importantly, with the potential future use of multidrug-resistant strains of B. anthracis as bioweapons, new antibiotics are needed as alternative therapeutics. In this blinded study, we assessed the protective efficacy of teixobactin, a recently discovered antibiotic, against inhalation anthrax infection in the adult rabbit model. New Zealand White rabbits were infected with a lethal dose of B. anthracis Ames spores via the inhalation route, and blood samples were collected at various times to assess antigenemia, bacteremia, tissue bacterial load, and antibody production. Treatments were administered upon detection of B. anthracis protective antigen in the animals’ sera. For comparison, a fully protective dose of levofloxacin was used as a positive control. Rabbits treated with teixobactin showed 100% survival following infection, and the bacteremia was completely resolved by 24–48 h post-treatment. In addition, the bacterial/spore loads in tissues of the animals treated with teixobactin were either zero or dramatically less relative to that of the negative control animals. Moreover, microscopic evaluation of the tissues revealed decreased pathology following treatment with teixobactin. Overall, these results show that teixobactin was protective against inhalation anthrax infection in the rabbit model, and they indicate the potential of teixobactin as a therapeutic for the disease.
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Affiliation(s)
- William S. Lawrence
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
- Correspondence: ; Tel.: +1-409-266-6919
| | - Jennifer E. Peel
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
| | - Satheesh K. Sivasubramani
- Directorate of Environmental Health Effects Laboratory, Naval Medical Research Unit, Dayton, OH 45433, USA;
| | - Wallace B. Baze
- Department of Comparative Medicine, University of Texas MD Anderson Cancer Center, Bastrop, TX 78602, USA;
| | - Elbert B. Whorton
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
| | - David W. C. Beasley
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jason E. Comer
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institutional Office of Regulated Nonclinical Studies, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Dallas E. Hughes
- NovoBiotic Pharmaceuticals, LLC, Cambridge, MA 02138, USA; (D.E.H.); (L.L.L.)
| | - Losee L. Ling
- NovoBiotic Pharmaceuticals, LLC, Cambridge, MA 02138, USA; (D.E.H.); (L.L.L.)
| | - Johnny W. Peterson
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA; (J.E.P.); (D.W.C.B.); (J.E.C.); (J.W.P.)
- Institute for Human Infections & Immunity, University of Texas Medical Branch, Galveston, TX 77555, USA;
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Pillai SP, Prentice KW, Ramage JG, DePalma L, Sarwar J, Parameswaran N, Bell M, Plummer A, Santos A, Singh A, Pillai CA, Thirunavvukarasu N, Manickam G, Avila JR, Sharma SK, Hoffmaster A, Anderson K, Morse SA, Venkateswaran KV, Hodge DR. Rapid Presumptive Identification of Bacillus anthracis Isolates Using the Tetracore RedLine Alert™ Test. Health Secur 2020; 17:334-343. [PMID: 31433282 DOI: 10.1089/hs.2019.0038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A comprehensive laboratory evaluation of the Tetracore RedLine Alert test, a lateral flow immunoassay (LFA) for the rapid presumptive identification of Bacillus anthracis, was conducted at 2 different test sites. The study evaluated the sensitivity of this assay using 16 diverse strains of B. anthracis grown on sheep blood agar (SBA) plates. In addition, 83 clinically relevant microorganisms were tested to assess the specificity of the RedLine Alert test. The results indicated that the RedLine Alert test for the presumptive identification of B. anthracis is highly robust, specific, and sensitive. RedLine Alert is a rapid test that has applicability for use in a clinical setting for ruling-in or ruling-out nonhemolytic colonies of Bacillus spp. grown on SBA medium as presumptive isolates of B. anthracis.
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Affiliation(s)
- Segaran P Pillai
- Segaran P. Pillai, PhD, is Director, Office of Laboratory Science and Safety, FDA Office of the Commissioner, Department of Health and Human Services, Silver Spring, MD
| | - Kristin W Prentice
- Kristin W. Prentice, MS, is an Associate, and Lindsay DePalma, MS, is a Staff Life Scientist; both at Booz Allen Hamilton, Rockville, MD
| | - Jason G Ramage
- Jason G. Ramage, MS, MBA, PMP, is Assistant Vice Chancellor for Research and Innovation and Director of Research Compliance, University of Arkansas, Fayetteville, AR
| | - Lindsay DePalma
- Kristin W. Prentice, MS, is an Associate, and Lindsay DePalma, MS, is a Staff Life Scientist; both at Booz Allen Hamilton, Rockville, MD
| | - Jawad Sarwar
- Jawad Sarwar, MS, is a Senior Research Scientist, and Nishanth Parameswaran is a Research Scientist; both at Omni Array Biotechnology, Rockville, MD
| | - Nishanth Parameswaran
- Jawad Sarwar, MS, is a Senior Research Scientist, and Nishanth Parameswaran is a Research Scientist; both at Omni Array Biotechnology, Rockville, MD
| | - Melissa Bell
- Melissa Bell, MS, is a Microbiologist, and Alex Hoffmaster, PhD, is Chief, Bacterial Special Pathogens Branch; both in the National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA
| | - Andrea Plummer
- Andrea Plummer and Alan Santos are Microbiologists, and Kodumudi Venkat Venkateswaran, PhD, is Chief Scientist; all at Tetracore, Inc., Rockville, MD
| | - Alan Santos
- Andrea Plummer and Alan Santos are Microbiologists, and Kodumudi Venkat Venkateswaran, PhD, is Chief Scientist; all at Tetracore, Inc., Rockville, MD
| | - Ajay Singh
- Ajay Singh, PhD, is a Research Scientist, Laulima Government Solutions, Contractor Support to USAMRICD Neurobiological Toxicology Branch, Analytical Toxicology Division, Aberdeen Proving Ground, MD
| | - Christine A Pillai
- Christine A. Pillai, Nagarajan Thirunavvukarasu, PhD, and Gowri Manickam, PhD, are ORISE Fellow Research Scientists, and Shashi K. Sharma, PhD, is a Research Microbiologist; all with the FDA Center for Food Safety and Applied Nutrition, Molecular Methods Development Branch, Division of Microbiology, Office of Regulatory Science, College Park, MD
| | - Nagarajan Thirunavvukarasu
- Christine A. Pillai, Nagarajan Thirunavvukarasu, PhD, and Gowri Manickam, PhD, are ORISE Fellow Research Scientists, and Shashi K. Sharma, PhD, is a Research Microbiologist; all with the FDA Center for Food Safety and Applied Nutrition, Molecular Methods Development Branch, Division of Microbiology, Office of Regulatory Science, College Park, MD
| | - Gowri Manickam
- Christine A. Pillai, Nagarajan Thirunavvukarasu, PhD, and Gowri Manickam, PhD, are ORISE Fellow Research Scientists, and Shashi K. Sharma, PhD, is a Research Microbiologist; all with the FDA Center for Food Safety and Applied Nutrition, Molecular Methods Development Branch, Division of Microbiology, Office of Regulatory Science, College Park, MD
| | - Julie R Avila
- Julie R. Avila, MS, is a Scientific Associate, Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA
| | - Shashi K Sharma
- Christine A. Pillai, Nagarajan Thirunavvukarasu, PhD, and Gowri Manickam, PhD, are ORISE Fellow Research Scientists, and Shashi K. Sharma, PhD, is a Research Microbiologist; all with the FDA Center for Food Safety and Applied Nutrition, Molecular Methods Development Branch, Division of Microbiology, Office of Regulatory Science, College Park, MD
| | - Alex Hoffmaster
- Melissa Bell, MS, is a Microbiologist, and Alex Hoffmaster, PhD, is Chief, Bacterial Special Pathogens Branch; both in the National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA
| | - Kevin Anderson
- Kevin Anderson, PhD, and David R. Hodge, PhD, are Program Managers, Science and Technology Directorate, US Department of Homeland Security, Washington, DC
| | - Stephen A Morse
- Stephen A. Morse, MSPH, PhD, is a Senior Advisor, CDC Division of Select Agents and Toxins, and is currently with IHRC, Inc., Atlanta, GA
| | - Kodumudi Venkat Venkateswaran
- Andrea Plummer and Alan Santos are Microbiologists, and Kodumudi Venkat Venkateswaran, PhD, is Chief Scientist; all at Tetracore, Inc., Rockville, MD
| | - David R Hodge
- Kevin Anderson, PhD, and David R. Hodge, PhD, are Program Managers, Science and Technology Directorate, US Department of Homeland Security, Washington, DC
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Perry MR, Ionin B, Barnewall RE, Vassar ML, Reece JJ, Park S, Lemiale L, Skiadopoulos MH, Shearer JD, Savransky V. Development of a guinea pig inhalational anthrax model for evaluation of post-exposure prophylaxis efficacy of anthrax vaccines. Vaccine 2020; 38:2307-2314. [PMID: 32029323 DOI: 10.1016/j.vaccine.2020.01.068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/06/2020] [Accepted: 01/22/2020] [Indexed: 11/29/2022]
Abstract
A next-generation anthrax vaccine candidate, AV7909, is being developed for post-exposure prophylaxis (PEP) of inhalational anthrax in combination with the recommended course of antimicrobial therapy. Clinical efficacy studies of anthrax countermeasures in humans are not ethical or feasible, therefore, licensure of AV7909 for PEP is being pursued under the US Food and Drug Administration (FDA) Animal Rule, which requires that evidence of effectiveness be demonstrated in an animal model of anthrax, where results of studies in such a model can establish reasonable likelihood of AV7909 to produce clinical benefit in humans. Initial development of a PEP model for inhalational anthrax included evaluation of post-exposure ciprofloxacin pharmacokinetics (PK), tolerability and survival in guinea pigs treated with various ciprofloxacin dosing regimens. Three times per day (TID) intraperitoneal (IP) dosing with 7.5 mg/kg of ciprofloxacin initiated 1 day following inhalational anthrax challenge and continued for 14 days was identified as a well tolerated partially curative ciprofloxacin treatment regimen. The added benefit of AV7909 vaccination was evaluated in guinea pigs given the partially curative ciprofloxacin treatment regimen. Groups of ciprofloxacin-treated guinea pigs were vaccinated. 1 and 8 days post-challenge with serial dilutions of AV7909, a 1:16 dilution of AVA, or normal saline. A group of untreated guinea pigs was included as a positive control to confirm lethal B. anthracis exposure. Post-exposure vaccination with the AV7909 anthrax vaccine candidate administered in combination with the partially curative ciprofloxacin treatment significantly increased survival of guinea pigs compared to ciprofloxacin treatment alone. These results suggest that the developed model can be useful in demonstrating added value of the vaccine for PEP.
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Affiliation(s)
- Mark R Perry
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Boris Ionin
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Roy E Barnewall
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Michelle L Vassar
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Joshua J Reece
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Sukjoon Park
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Laurence Lemiale
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | | | - Jeffry D Shearer
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Vladimir Savransky
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA.
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11
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Savransky V, Lacy M, Ionin B, Skiadopoulos MH, Shearer J. Repeat-Dose Toxicity Study of a Lyophilized Recombinant Protective Antigen-Based Anthrax Vaccine Adjuvanted With CpG 7909. Int J Toxicol 2020; 38:163-172. [PMID: 31179828 DOI: 10.1177/1091581819848722] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A recombinant protective antigen (rPA) anthrax vaccine candidate (rPA7909) was developed as a next-generation vaccine indicated for postexposure prophylaxis of disease resulting from suspected or confirmed Bacillus anthracis exposure. The lyophilized form of rPA7909-vaccinated candidate contains 75 µg purified rPA, 750 µg aluminum (as Alhydrogel adjuvant), and 250 µg of an immunostimulatory Toll-like receptor 9 agonist oligodeoxynucleotide CpG 7909 in a 0.5 mL phosphate-buffered suspension. General toxicity and local reactogenicity were evaluated in Sprague Dawley rats vaccinated with the full human dose of rPA7909 by intramuscular injection. Animals were immunized on study days 1, 15, and 29. Control groups were administered diluent only or adjuvant control (excipients, CpG 7909, and Alhydrogel adjuvant in diluent) intramuscularly at the same dose volume and according to the same schedule used for rPA7909. Toxicity was assessed based on the results of clinical observations, physical examinations, body weights, injection site reactogenicity, ophthalmology, clinical pathology (hematology, coagulation, and serum chemistry), organ weights, and macroscopic and microscopic pathology evaluation. The immune response to rPA7909 vaccination was confirmed by measuring serum anti-PA immunoglobulin G levels. The rPA7909 vaccine produced no apparent systemic toxicity and only transient reactogenicity at the injection site. The injection site reaction from animals receiving the adjuvant control was very similar to those receiving rPA7909 with respect to the inflammation. The inflammatory response observed in the injection site and the draining lymph nodes was consistent with expected immune stimulation. The overall results indicated a favorable safety profile for rPA7909.
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Affiliation(s)
| | - Michael Lacy
- 1 Emergent BioSolutions Inc, Gaithersburg, MD, USA
| | - Boris Ionin
- 1 Emergent BioSolutions Inc, Gaithersburg, MD, USA
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12
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Duplantier AJ, Shurtleff AC, Miller C, Chiang CY, Panchal RG, Sunay M. Combating biothreat pathogens: ongoing efforts for countermeasure development and unique challenges. DRUG DISCOVERY TARGETING DRUG-RESISTANT BACTERIA 2020. [PMCID: PMC7258707 DOI: 10.1016/b978-0-12-818480-6.00007-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Research to discover and develop antibacterial and antiviral drugs with potent activity against pathogens of biothreat concern presents unique methodological and process-driven challenges. Herein, we review laboratory approaches for finding new antibodies, antibiotics, and antiviral molecules for pathogens of biothreat concern. Using high-throughput screening techniques, molecules that directly inhibit a pathogen’s entry, replication, or growth can be identified. Alternatively, molecules that target host proteins can be interesting targets for development when countering biothreat pathogens, due to the modulation of the host immune response or targeting proteins that interfere with the pathways required by the pathogen for replication. Monoclonal and cocktail antibody therapies approved by the Food and Drug Administration for countering anthrax and under development for treatment of Ebola virus infection are discussed. A comprehensive tabular review of current in vitro, in vivo, pharmacokinetic and efficacy datasets has been presented for biothreat pathogens of greatest concern. Finally, clinical trials and animal rule or traditional drug approval pathways are also reviewed. Opinions; interpretations; conclusions; and recommendations are those of the authors and are not necessarily endorsed by the US Army.
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13
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Autumn Smiley M, Sanford DC, Triplett CA, Callahan D, Frolov V, Look J, Ruiz C, Reece JJ, Miles A, Ruiz E, Ionin B, Shearer JD, Savransky V. Comparative immunogenicity and efficacy of thermostable (lyophilized) and liquid formulation of anthrax vaccine candidate AV7909. Vaccine 2019; 37:6356-6361. [PMID: 31530467 PMCID: PMC6764848 DOI: 10.1016/j.vaccine.2019.09.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/22/2019] [Accepted: 09/05/2019] [Indexed: 11/16/2022]
Abstract
The anthrax vaccine candidate AV7909 is being developed as a next-generation vaccine for a post-exposure prophylaxis (PEP) indication against anthrax. AV7909 consists of the anthrax vaccine adsorbed (AVA) (Emergent BioSolutions Inc., Lansing, MI) bulk drug substance adjuvanted with the immunostimulatory oligodeoxynucleotide (ODN) compound, CPG 7909. The addition of CPG 7909 to AVA enhances both the magnitude and the kinetics of antibody responses in animals and human subjects, making AV7909 a suitable next-generation vaccine for use in a PEP setting. Emergent has produced a thermostable (lyophilized) formulation of AV7909 vaccine utilizing drying technology. The purpose of the study described here was to assess the immunogenicity and efficacy of the lyophilized formulation of the AV7909 vaccine candidate as compared with the liquid formulation in the guinea pig general-use prophylaxis (GUP) model. The study also provides initial information on the relationship between the immune response induced by the thermostable formulation of the vaccine, as measured by the toxin neutralization assay (TNA), and animal survival following lethal anthrax aerosol challenge. Results demonstrated that there were no significant differences in the immunogenicity or efficacy of lyophilized AV7909 against lethal anthrax spore aerosol challenge in the guinea pig model as compared to liquid AV7909. For both vaccine formulations, logistic regression modeling showed that the probability of survival increased as the pre-challenge antibody levels increased.
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Affiliation(s)
- M Autumn Smiley
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Daniel C Sanford
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Cheryl A Triplett
- Battelle Biomedical Research Center, 1425 Plain City Georgesville Road, JM7, West Jefferson, OH 46162, USA
| | - Daniel Callahan
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Vladimir Frolov
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Jee Look
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Christian Ruiz
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Joshua J Reece
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Aaron Miles
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Ericka Ruiz
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Boris Ionin
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Jeffry D Shearer
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA
| | - Vladimir Savransky
- Emergent BioSolutions Inc., 300 Professional Drive, Gaithersburg, MD 20879, USA.
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14
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Zeptomole per milliliter detection and quantification of edema factor in plasma by LC-MS/MS yields insights into toxemia and the progression of inhalation anthrax. Anal Bioanal Chem 2019; 411:2493-2509. [PMID: 30911800 DOI: 10.1007/s00216-019-01730-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/06/2019] [Accepted: 02/26/2019] [Indexed: 12/28/2022]
Abstract
Inhalation of Bacillus anthracis spores can cause a rapidly progressing fatal infection. B. anthracis secretes three protein toxins: lethal factor (LF), edema factor (EF), and protective antigen (PA). EF and LF may circulate as free or PA-bound forms. Both free EF (EF) and PA-bound-EF (ETx) have adenylyl cyclase activity converting ATP to cAMP. We developed an adenylyl cyclase activity-based method for detecting and quantifying total EF (EF+ETx) in plasma. The three-step method includes magnetic immunocapture with monoclonal antibodies, reaction with ATP generating cAMP, and quantification of cAMP by isotope-dilution HPLC-MS/MS. Total EF was quantified from 5PL regression of cAMP vs ETx concentration. The detection limit was 20 fg/mL (225 zeptomoles/mL for the 89 kDa protein). Relative standard deviations for controls with 0.3, 6.0, and 90 pg/mL were 11.7-16.6% with 91.2-99.5% accuracy. The method demonstrated 100% specificity in 238 human serum/plasma samples collected from unexposed healthy individuals, and 100% sensitivity in samples from 3 human and 5 rhesus macaques with inhalation anthrax. Analysis of EF in the rhesus macaques showed that it was detected earlier post-exposure than B. anthracis by culture and PCR. Similar to LF, the kinetics of EF over the course of infection were triphasic, with an initial rise (phase-1), decline (phase-2), and final rapid rise (phase-3). EF levels were ~ 2-4 orders of magnitude lower than LF during phase-1 and phase-2 and only ~ 6-fold lower at death/euthanasia. Analysis of EF improves early diagnosis and adds to our understanding of anthrax toxemia throughout infection. The LF/EF ratio may also indicate the stage of infection and need for advanced treatments.
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15
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Solano MI, Woolfitt AR, Boyer AE, Lins RC, Isbell K, Gallegos-Candela M, Moura H, Pierce CL, Barr JR. Accurate and selective quantification of anthrax protective antigen in plasma by immunocapture and isotope dilution mass spectrometry. Analyst 2019; 144:2264-2274. [PMID: 30810119 PMCID: PMC7015108 DOI: 10.1039/c8an02479k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Anthrax protective antigen (83 kDa, PA83) is an essential component of two major binary toxins produced by Bacillus anthracis, lethal toxin (LTx) and edema toxin (ETx). During infection, LTx and ETx contribute to immune collapse, endothelial dysfunction, hemorrhage and high mortality. Following protease cleavage on cell receptors or in circulation, the 20 kDa (PA20) N-terminus is released, activating the 63 kDa (PA63) form which binds lethal factor (LF) and edema factor (EF), facilitating their entry into their cellular targets. Several ELISA-based PA methods previously developed are primarily qualitative or semi-quantitative. Here, we combined protein immunocapture, tryptic digestion and isotope dilution liquid chromatography-mass spectrometry (LC-MS/MS), to develop a highly selective and sensitive method for detection and accurate quantification of total-PA (PA83 + PA63) and PA83. Two tryptic peptides in the 63 kDa region measure total-PA and three in the 20 kDa region measure PA83 alone. Detection limits range from 1.3-2.9 ng mL-1 PA in 100 μL of plasma. Spiked recovery experiments with combinations of PA83, PA63, LF and EF in plasma showed that PA63 and PA83 were quantified accurately against the PA83 standard and that LF and EF did not interfere with accuracy. Applied to a study of inhalation anthrax in rhesus macaques, total-PA suggested triphasic kinetics, similar to that previously observed for LF and EF. This study is the first to report circulating PA83 in inhalation anthrax, typically at less than 4% of the levels of PA63, providing the first evidence that activated PA63 is the primary form of PA throughout infection.
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Affiliation(s)
- Maria I Solano
- Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Highway, Atlanta, GA 30341, USA.
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16
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Malik A, Gupta M, Mani R, Gogoi H, Bhatnagar R. Trimethyl Chitosan Nanoparticles Encapsulated Protective Antigen Protects the Mice Against Anthrax. Front Immunol 2018; 9:562. [PMID: 29616046 PMCID: PMC5870345 DOI: 10.3389/fimmu.2018.00562] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/06/2018] [Indexed: 01/08/2023] Open
Abstract
Anthrax is an era old deadly disease against which there are only two currently available licensed vaccines named anthrax vaccine adsorbed and precipitated (AVP). Though they can provide a protective immunity, their multiple side-effects owing to their ill-defined composition and presence of toxic proteins (LF and EF) of Bacillus anthracis, the causative organism of anthrax, in the vaccine formulation makes their widespread use objectionable. Hence, an anthrax vaccine that contains well-defined and controlled components would be highly desirable. In this context, we have evaluated the potential of various vaccine formulations comprising of protective antigen (PA) encapsulated trimethyl-chitosan nanoparticles (TMC-PA) in conjunction with either CpG-C ODN 2395 (CpG) or Poly I:C. Each formulation was administered via three different routes, viz., subcutaneous (SC), intramuscular (IM), and intraperitoneal in female BALB/c mice. Irrespective of the route of immunization, CpG or Poly I:C adjuvanted TMC-PA nanoparticles induced a significantly higher humoral response (total serum IgG and its isotypes viz., IgG1, IgG2a, and IgG2b), compared to their CpG or Poly I:C PA counterparts. This clearly demonstrates the synergistic behavior of CpG and Poly I:C with TMC nanoparticles. The adjuvant potential of TMC nanoparticles could be observed in all the three routes as the TMC-PA nanoparticles by themselves induced IgG titers (1-1.5 × 105) significantly higher than both CpG PA and Poly I:C PA groups (2-8 × 104). The effect of formulations on T-helper (Th) cell development was assessed by quantifying the Th1-dependant (TNF-α, IFN-γ, and IL-2), Th2-dependant (IL-4, IL-6, and IL-10), and Th17-type (IL-17A) cytokines. Adjuvanation with CpG and Poly I:C, the TMC-PA nanoparticles triggered a Th1 skewed immune response, as suggested by an increase in the levels of total IgG2a along with IFN-γ cytokine production. Interestingly, the TMC-PA group showed a Th2-biased immune response. Upon challenge with the B. anthracis Ames strain, CpG and Poly I:C adjuvanted TMC-PA nanoparticles immunized via the SC and IM routes showed the highest protective efficacy of ~83%. Altogether, the results suggest that CpG or Poly I:C adjuvanted, PA-loaded TMC nanoparticles could be used as an effective, non-toxic, second generation subunit-vaccine candidate against anthrax.
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Affiliation(s)
- Anshu Malik
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Manish Gupta
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Rajesh Mani
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Himanshu Gogoi
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - Rakesh Bhatnagar
- Molecular Biology and Genetic Engineering Laboratory, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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17
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Goldstein JM, Lee J, Tang X, Boyer AE, Barr JR, Bagarozzi DA, Quinn CP. Phage Display Analysis of Monoclonal Antibody Binding to Anthrax Toxin Lethal Factor. Toxins (Basel) 2017. [PMCID: PMC5535168 DOI: 10.3390/toxins9070221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
AVR1674 and AVR1675 are monoclonal antibodies (mAbs) that bind with high specificity to anthrax toxin lethal factor (LF) and lethal toxin (LTx). These mAbs have been used as pivotal reagents to develop anthrax toxin detection tests using mass spectrometry. The mAbs were demonstrated to bind LF with good affinity (KD 10−7–10−9 M) and to enhance LF-mediated cleavage of synthetic peptide substrates in vitro. Sequence analysis indicated that the mAbs shared 100% amino acid identity in their complementarity determining regions (CDR). A phage display library based on a combinatorial library of random heptapeptides fused to the pIII coat protein of M13 phage was enriched and screened to identify peptide sequences with mAb binding properties. Selection and sequence analysis of 18 anti-LF-reactive phage clones identified a 7-residue (P1–P7) AVR1674/1675 consensus target binding sequence of TP1-XP2-K/RP3-DP4-D/EP5-ZP6-X/ZP7 (X = aromatic, Z = non-polar). The phage peptide sequence with highest affinity binding to AVR1674/1675 was identified as T-F-K-D-E-I-V. Synthetic oligopeptides were designed based on the phage sequences and interacted with mAbs with high affinity (KD ~ 10−9 M). Single amino acid substitutions of A, H, or Q in the peptides identified positions P1–P5 as critical residues for mAb-peptide interactions. CLUSTALW alignment of phage sequences with native LF implicated residues 644–650 (sequence T-H-Q-D-E-I-Y) as a putative linear epitope component located within a structural loop (L2) of LF Domain IV. The activation effects of these mAbs contribute to the analytic sensitivity of function-based LF detection assays.
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Affiliation(s)
- Jason M. Goldstein
- Reagent and Diagnostic Services Branch, Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, MS-A03, 1600 Clifton Road, Atlanta, GA 30333, USA; (J.L.); (X.T.); (D.A.B.J.)
- Correspondence: ; Tel.: +1-404-639-2258
| | - Joo Lee
- Reagent and Diagnostic Services Branch, Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, MS-A03, 1600 Clifton Road, Atlanta, GA 30333, USA; (J.L.); (X.T.); (D.A.B.J.)
| | - Xiaoling Tang
- Reagent and Diagnostic Services Branch, Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, MS-A03, 1600 Clifton Road, Atlanta, GA 30333, USA; (J.L.); (X.T.); (D.A.B.J.)
| | - Anne E. Boyer
- Clinical Chemistry Branch, Division of Laboratory Services, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; (A.E.B.); (J.R.B.)
| | - John R. Barr
- Clinical Chemistry Branch, Division of Laboratory Services, National Center for Environmental Health, Centers for Disease Control and Prevention, 4770 Buford Hwy, NE, Atlanta, GA 30341, USA; (A.E.B.); (J.R.B.)
| | - Dennis A. Bagarozzi
- Reagent and Diagnostic Services Branch, Division of Scientific Resources, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, MS-A03, 1600 Clifton Road, Atlanta, GA 30333, USA; (J.L.); (X.T.); (D.A.B.J.)
| | - Conrad P. Quinn
- Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, MS-D17, 1600 Clifton Road, Atlanta, GA 30333, USA;
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18
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Protection against inhalation anthrax by immunization with Salmonella enterica serovar Typhi Ty21a stably producing protective antigen of Bacillus anthracis. NPJ Vaccines 2017; 2:17. [PMID: 29263873 PMCID: PMC5627300 DOI: 10.1038/s41541-017-0018-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 04/28/2017] [Accepted: 05/11/2017] [Indexed: 02/08/2023] Open
Abstract
The national blueprint for biodefense concluded that the United States is underprepared for biological threats. The licensed anthrax vaccine absorbed vaccine, BioThrax, requires administration of at least 3–5 intramuscular doses. The anthrax vaccine absorbed vaccine consists of complex cell-free culture filtrates of a toxigenic Bacillus anthracis strain and causes tenderness at the injection site and significant adverse events. We integrated a codon-optimized, protective antigen gene of B. anthracis (plus extracellular secretion machinery), into the chromosome of the licensed, oral, live-attenuated typhoid fever vaccineTy21a to form Ty21a-PA-01 and demonstrated excellent expression of the gene encoding protective antigen. We produced the vaccine in a 10-L fermenter; foam-dried and vialed it, and characterized the dried product. The vaccine retained ~50% viability for 20 months at ambient temperature. Sera from animals immunized by the intraperitoneal route had high levels of anti-protective antigen antibodies by enzyme-linked immunosorbent assay and anthrax lethal toxin-neutralizing activity. Immunized mice were fully protected against intranasal challenge with ~5 LD50 of B. anthracis Sterne spores, and 70% (7/10) of vaccinated rabbits were protected against aerosol challenge with 200 LD50 of B. anthracis Ames spores. There was a significant correlation between protection and antibody levels determined by enzyme-linked immunosorbent assay and toxin-neutralizing activity. These data provide the foundation for achievement of our ultimate goal, which is to develop an oral anthrax vaccine that is stable at ambient temperatures and induces the rapid onset of durable, high-level protection after a 1-week immunization regimen. A vaccine candidate for anthrax infection shows promise for improving preparedness for a biological attack. Bacillus anthracis, the bacterium responsible for anthrax is a top-tier bioterrorism agent due to its high lethality and spore stability. The current FDA-approved anthrax vaccine and other vaccine candidates in development lack ease of preparation, have short shelf lives and adverse effects. B. Kim Lee Sim of Protein Potential LLC and her collaborators combined key B. anthracis genetic material into an existing typhoid vaccine. The vaccine vector possesses high stability, a strong safety record, and offers long-term protection after oral administration, which Sim’s group hopes to preserve in their candidate anthrax vaccine. The team showed that their hybrid vaccine conferred excellent protection in rabbits and a short vaccination regimen, and suggest further studies into its suitability for human vaccine studies.
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Ramage JG, Prentice KW, DePalma L, Venkateswaran KS, Chivukula S, Chapman C, Bell M, Datta S, Singh A, Hoffmaster A, Sarwar J, Parameswaran N, Joshi M, Thirunavkkarasu N, Krishnan V, Morse S, Avila JR, Sharma S, Estacio PL, Stanker L, Hodge DR, Pillai SP. Comprehensive Laboratory Evaluation of a Highly Specific Lateral Flow Assay for the Presumptive Identification of Bacillus anthracis Spores in Suspicious White Powders and Environmental Samples. Health Secur 2017; 14:351-65. [PMID: 27661796 DOI: 10.1089/hs.2016.0041] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We conducted a comprehensive, multiphase laboratory evaluation of the Anthrax BioThreat Alert(®) test strip, a lateral flow immunoassay (LFA) for the rapid detection of Bacillus anthracis spores. The study, conducted at 2 sites, evaluated this assay for the detection of spores from the Ames and Sterne strains of B. anthracis, as well as those from an additional 22 strains. Phylogenetic near neighbors, environmental background organisms, white powders, and environmental samples were also tested. The Anthrax LFA demonstrated a limit of detection of about 10(6) spores/mL (ca. 1.5 × 10(5) spores/assay). In this study, overall sensitivity of the LFA was 99.3%, and the specificity was 98.6%. The results indicated that the specificity, sensitivity, limit of detection, dynamic range, and repeatability of the assay support its use in the field for the purpose of qualitatively evaluating suspicious white powders and environmental samples for the presumptive presence of B. anthracis spores.
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Huang E, Pillai SK, Bower WA, Hendricks KA, Guarnizo JT, Hoyle JD, Gorman SE, Boyer AE, Quinn CP, Meaney-Delman D. Antitoxin Treatment of Inhalation Anthrax: A Systematic Review. Health Secur 2016; 13:365-77. [PMID: 26690378 DOI: 10.1089/hs.2015.0032] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Concern about use of anthrax as a bioweapon prompted development of novel anthrax antitoxins for treatment. Clinical guidelines for the treatment of anthrax recommend antitoxin therapy in combination with intravenous antimicrobials; however, a large-scale or mass anthrax incident may exceed antitoxin availability and create a need for judicious antitoxin use. We conducted a systematic review of antitoxin treatment of inhalation anthrax in humans and experimental animals to inform antitoxin recommendations during a large-scale or mass anthrax incident. A comprehensive search of 11 databases and the FDA website was conducted to identify relevant animal studies and human reports: 28 animal studies and 3 human cases were identified. Antitoxin monotherapy at or shortly after symptom onset demonstrates increased survival compared to no treatment in animals. With early treatment, survival did not differ between antimicrobial monotherapy and antimicrobial-antitoxin therapy in nonhuman primates and rabbits. With delayed treatment, antitoxin-antimicrobial treatment increased rabbit survival. Among human cases, addition of antitoxin to combination antimicrobial treatment was associated with survival in 2 of the 3 cases treated. Despite the paucity of human data, limited animal data suggest that adjunctive antitoxin therapy may improve survival. Delayed treatment studies suggest improved survival with combined antitoxin-antimicrobial therapy, although a survival difference compared with antimicrobial therapy alone was not demonstrated statistically. In a mass anthrax incident with limited antitoxin supplies, antitoxin treatment of individuals who have not demonstrated a clinical benefit from antimicrobials, or those who present with more severe illness, may be warranted. Additional pathophysiology studies are needed, and a point-of-care assay correlating toxin levels with clinical status may provide important information to guide antitoxin use during a large-scale anthrax incident.
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21
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Seo Y, Kim JE, Jeong Y, Lee KH, Hwang J, Hong J, Park H, Choi J. Engineered nanoconstructs for the multiplexed and sensitive detection of high-risk pathogens. NANOSCALE 2016; 8:1944-1951. [PMID: 26462853 DOI: 10.1039/c5nr06230f] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Many countries categorize the causative agents of severe infectious diseases as high-risk pathogens. Given their extreme infectivity and potential to be used as biological weapons, a rapid and sensitive method for detection of high-risk pathogens (e.g., Bacillus anthracis, Francisella tularensis, Yersinia pestis, and Vaccinia virus) is highly desirable. Here, we report the construction of a novel detection platform comprising two units: (1) magnetic beads separately conjugated with multiple capturing antibodies against four different high-risk pathogens for simple and rapid isolation, and (2) genetically engineered apoferritin nanoparticles conjugated with multiple quantum dots and detection antibodies against four different high-risk pathogens for signal amplification. For each high-risk pathogen, we demonstrated at least 10-fold increase in sensitivity compared to traditional lateral flow devices that utilize enzyme-based detection methods. Multiplexed detection of high-risk pathogens in a sample was also successful by using the nanoconstructs harboring the dye molecules with fluorescence at different wavelengths. We ultimately envision the use of this novel nanoprobe detection platform in future applications that require highly sensitive on-site detection of high-risk pathogens.
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Affiliation(s)
- Youngmin Seo
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea.
| | - Ji-eun Kim
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea.
| | - Yoon Jeong
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea.
| | - Kwan Hong Lee
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea. and Department of Bionano Engineering, Hanyang University ERICA, Ansan 426-791, Korea
| | - Jangsun Hwang
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea.
| | - Jongwook Hong
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea. and Department of Bionano Engineering, Hanyang University ERICA, Ansan 426-791, Korea
| | - Hansoo Park
- School of Integrative Engineering, Chung-Ang University, Seoul 156-756, Korea.
| | - Jonghoon Choi
- Department of Bionano Technology, Graduate School, Hanyang University, Seoul 133-791, Korea. and Department of Bionano Engineering, Hanyang University ERICA, Ansan 426-791, Korea
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Muller J, Gwozdz J, Hodgeman R, Ainsworth C, Kluver P, Czarnecki J, Warner S, Fegan M. Diagnostic performance characteristics of a rapid field test for anthrax in cattle. Prev Vet Med 2015; 120:277-82. [PMID: 25956134 DOI: 10.1016/j.prevetmed.2015.03.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 03/25/2015] [Accepted: 03/25/2015] [Indexed: 10/23/2022]
Abstract
Although diagnosis of anthrax can be made in the field with a peripheral blood smear, and in the laboratory with bacterial culture or molecular based tests, these tests require either considerable experience or specialised equipment. Here we report on the evaluation of the diagnostic sensitivity and specificity of a simple and rapid in-field diagnostic test for anthrax, the anthrax immunochromatographic test (AICT). The AICT detects the protective antigen (PA) component of the anthrax toxin present within the blood of an animal that has died from anthrax. The test provides a result in 15min and offers the advantage of avoiding the necessity for on-site necropsy and subsequent occupational risks and environmental contamination. The specificity of the test was determined by testing samples taken from 622 animals, not infected with Bacillus anthracis. Diagnostic sensitivity was estimated on samples taken from 58 animals, naturally infected with B. anthracis collected over a 10-year period. All samples used to estimate the diagnostic sensitivity and specificity of the AICT were also tested using the gold standard of bacterial culture. The diagnostic specificity of the test was estimated to be 100% (99.4-100%; 95% CI) and the diagnostic sensitivity was estimated to be 93.1% (83.3-98.1%; 95% CI) (Clopper-Pearson method). Four samples produced false negative AICT results. These were among 9 samples, all of which tested positive for B. anthracis by culture, where there was a time delay between collection and testing of >48h and/or the samples were collected from animals that were >48h post-mortem. A statistically significant difference (P<0.001; Fishers exact test) was found between the ability of the AICT to detect PA in samples from culture positive animals <48h post-mortem, 49 of 49, Se=100% (92.8-100%; 95% CI) compared with samples tested >48h post-mortem 5 of 9 Se=56% (21-86.3%; 95% CI) (Clopper-Pearson method). Based upon these results a post hoc cut-off for use of the AICT of 48h post-mortem was applied, Se=100% (92.8-100%; 95% CI) and Sp=100% (99.4-100%; 95% CI). The high diagnostic sensitivity and specificity and the simplicity of the AICT enables it to be used for active surveillance in areas with a history of anthrax, or used as a preliminary tool in investigating sudden, unexplained death in cattle.
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Affiliation(s)
- Janine Muller
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia
| | - Jacek Gwozdz
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia
| | - Rachel Hodgeman
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia
| | - Catherine Ainsworth
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia
| | - Patrick Kluver
- Livestock Biosecurity Networks, National Farmers Federation House, Canberra, ACT 2601, Australia
| | - Jill Czarnecki
- Biological Defense Research Directorate, Naval Medical Research Center-Frederick, 8400 Research Plaza, Fort Detrick, MD 21702, USA
| | - Simone Warner
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia
| | - Mark Fegan
- Department of Economic Development, Jobs, Transport and Resources, Biosciences Research Division, AgriBio, Centre for AgriBioscience, 5 Ring Road, La Trobe University Research and Development Park, Bundoora, VIC 3086, Australia.
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Efficacy and immunogenicity of single-dose AdVAV intranasal anthrax vaccine compared to anthrax vaccine absorbed in an aerosolized spore rabbit challenge model. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:430-9. [PMID: 25673303 DOI: 10.1128/cvi.00690-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
AdVAV is a replication-deficient adenovirus type 5-vectored vaccine expressing the 83-kDa protective antigen (PA83) from Bacillus anthracis that is being developed for the prevention of disease caused by inhalation of aerosolized B. anthracis spores. A noninferiority study comparing the efficacy of AdVAV to the currently licensed Anthrax Vaccine Absorbed (AVA; BioThrax) was performed in New Zealand White rabbits using postchallenge survival as the study endpoint (20% noninferiority margin for survival). Three groups of 32 rabbits were vaccinated with a single intranasal dose of AdVAV (7.5 × 10(7), 1.5 × 10(9), or 3.5 × 10(10) viral particles). Three additional groups of 32 animals received two doses of either intranasal AdVAV (3.5 × 10(10) viral particles) or intramuscular AVA (diluted 1:16 or 1:64) 28 days apart. The placebo group of 16 rabbits received a single intranasal dose of AdVAV formulation buffer. All animals were challenged via the inhalation route with a targeted dose of 200 times the 50% lethal dose (LD50) of aerosolized B. anthracis Ames spores 70 days after the initial vaccination and were followed for 3 weeks. PA83 immunogenicity was evaluated by validated toxin neutralizing antibody and serum anti-PA83 IgG enzyme-linked immunosorbent assays (ELISAs). All animals in the placebo cohort died from the challenge. Three of the four AdVAV dose cohorts tested, including two single-dose cohorts, achieved statistical noninferiority relative to the AVA comparator group, with survival rates between 97% and 100%. Vaccination with AdVAV also produced antibody titers with earlier onset and greater persistence than vaccination with AVA.
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Chang HH, Chiang YW, Lin TK, Lin GL, Lin YY, Kau JH, Huang HH, Hsu HL, Wang JH, Sun DS. Erythrocytic mobilization enhanced by the granulocyte colony-stimulating factor is associated with reduced anthrax-lethal-toxin-induced mortality in mice. PLoS One 2014; 9:e111149. [PMID: 25384016 PMCID: PMC4226491 DOI: 10.1371/journal.pone.0111149] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/26/2014] [Indexed: 12/27/2022] Open
Abstract
Anthrax lethal toxin (LT), one of the primary virulence factors of Bacillus anthracis, causes anthrax-like symptoms and death in animals. Experiments have indicated that levels of erythrocytopenia and hypoxic stress are associated with disease severity after administering LT. In this study, the granulocyte colony-stimulating factor (G-CSF) was used as a therapeutic agent to ameliorate anthrax-LT- and spore-induced mortality in C57BL/6J mice. We demonstrated that G-CSF promoted the mobilization of mature erythrocytes to peripheral blood, resulting in a significantly faster recovery from erythrocytopenia. In addition, combined treatment using G-CSF and erythropoietin tended to ameliorate B. anthracis-spore-elicited mortality in mice. Although specific treatments against LT-mediated pathogenesis remain elusive, these results may be useful in developing feasible strategies to treat anthrax.
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Affiliation(s)
- Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Ya-Wen Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ting-Kai Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Guan-Ling Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - You-Yen Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Jyh-Hwa Kau
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Jen-Hung Wang
- Department of Medical Research, Tzu Chi General Hospital, Hualien, Taiwan
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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25
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Efficacy and safety of AVP-21D9, an anthrax monoclonal antibody, in animal models and humans. Antimicrob Agents Chemother 2014; 58:3618-25. [PMID: 24733473 DOI: 10.1128/aac.02295-13] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Timely administration of antibiotics approved for the treatment of anthrax disease may prevent associated morbidity and mortality. However, any delay in initiating antimicrobial therapy may result in increased mortality, as inhalational anthrax progresses rapidly to the toxemic phase of disease. An anthrax antitoxin, AVP-21D9, also known as Thravixa (fully human anthrax monoclonal antibody), is being developed as a therapeutic agent against anthrax toxemia. The efficacy of AVP-21D9 in B. anthracis-infected New Zealand White rabbits and in cynomolgus macaques was evaluated, and its safety and pharmacokinetics were assessed in healthy human volunteers. The estimated mean elimination half-life values of AVP-21D9 in surviving anthrax-challenged rabbits and nonhuman primates (NHPs) ranged from approximately 2 to 4 days and 6 to 11 days, respectively. In healthy humans, the mean elimination half-life was in the range of 20 to 27 days. Dose proportionality was observed for the maximum serum concentration (Cmax) of AVP-21D9 and the area under the concentration-time curve (AUC). In therapeutic efficacy animal models, treatment with AVP-21D9 resulted in survival of up to 92% of the rabbits and up to 67% of the macaques. Single infusions of AVP-21D9 were well tolerated in healthy adult volunteers across all doses evaluated, and no serious adverse events were reported. (This study has been registered at ClinicalTrials.gov under registration no. NCT01202695.).
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26
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Ramachandran G. Gram-positive and gram-negative bacterial toxins in sepsis: a brief review. Virulence 2014; 5:213-8. [PMID: 24193365 PMCID: PMC3916377 DOI: 10.4161/viru.27024] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 10/28/2013] [Accepted: 10/31/2013] [Indexed: 12/31/2022] Open
Abstract
Bacterial sepsis is a major cause of fatality worldwide. Sepsis is a multi-step process that involves an uncontrolled inflammatory response by the host cells that may result in multi organ failure and death. Both gram-negative and gram-positive bacteria play a major role in causing sepsis. These bacteria produce a range of virulence factors that enable them to escape the immune defenses and disseminate to remote organs, and toxins that interact with host cells via specific receptors on the cell surface and trigger a dysregulated immune response. Over the past decade, our understanding of toxins has markedly improved, allowing for new therapeutic strategies to be developed. This review summarizes some of these toxins and their role in sepsis.
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Affiliation(s)
- Girish Ramachandran
- Center for Vaccine Development; Department of Medicine; University of Maryland School of Medicine; Baltimore, MD USA
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27
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Kim DJ, Park HC, Sohn IY, Jung JH, Yoon OJ, Park JS, Yoon MY, Lee NE. Electrical graphene aptasensor for ultra-sensitive detection of anthrax toxin with amplified signal transduction. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:3352-3360. [PMID: 23589198 DOI: 10.1002/smll.201203245] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 01/23/2013] [Indexed: 06/02/2023]
Abstract
Detection of the anthrax toxin, the protective antigen (PA), at the attomolar (aM) level is demonstrated by an electrical aptamer sensor based on a chemically derived graphene field-effect transistor (FET) platform. Higher affinity of the aptamer probes to PA in the aptamer-immobilized FET enables significant improvements in the limit of detection (LOD), dynamic range, and sensitivity compared to the antibody-immobilized FET. Transduction signal enhancement in the aptamer FET due to an increase in captured PA molecules results in a larger 30 mV/decade shift in the charge neutrality point (Vg,min ) as a sensitivity parameter, with the dynamic range of the PA concentration between 12 aM (LOD) and 120 fM. An additional signal enhancement is obtained by the secondary aptamer-conjugated gold nanoparticles (AuNPs-aptamer), which have a sandwich structure of aptamer/PA/aptamer-AuNPs, induce an increase in charge-doping in the graphene channel, resulting in a reduction of the LOD to 1.2 aM with a three-fold increase in the Vg,min shift.
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Affiliation(s)
- Duck-Jin Kim
- Department of Chemistry, Hanyang University, Seoul 133-791, Korea
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28
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Antonelli AC, Zhang Y, Golub LM, Johnson F, Simon SR. Inhibition of anthrax lethal factor by curcumin and chemically modified curcumin derivatives. J Enzyme Inhib Med Chem 2013; 29:663-9. [PMID: 24102525 PMCID: PMC4196590 DOI: 10.3109/14756366.2013.837901] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Curcuma longa Curcumin (diferuloylmethane), the active ingredient in the eastern spice turmeric (Curcuma longa), has been shown to inhibit the activities of numerous enzymes and signaling molecules involved in cancer, bacterial and viral infections and inflammatory diseases. We have investigated the inhibitory activities of curcumin and chemically modified curcumin (CMC) derivatives toward lethal factor (LF), the proteolytic component of anthrax toxin produced by the bacterium Bacillus anthracis. Curcumin (Compound 1) appears to inhibit the catalytic activity of LF through a mixture of inhibitory mechanisms, without significant compromise to the binding of oligopeptide substrates, and one CMC derivative in particular, Compound 3 (4-phenylaminocarbonylbis-demethoxycurcumin), is capable of inhibiting LF with potency comparable with the parent compound, while also showing improved solubility and stability. The quantitative reduction in catalytic activity achieved by the different CMC derivatives appears to be a function of the proportion of the multiple mechanisms through which they inhibit the enzyme.
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29
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Tevell Åberg A, Björnstad K, Hedeland M. Mass Spectrometric Detection of Protein-Based Toxins. Biosecur Bioterror 2013; 11 Suppl 1:S215-26. [DOI: 10.1089/bsp.2012.0072] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Annica Tevell Åberg
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - Kristian Björnstad
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
| | - Mikael Hedeland
- Annica Tevell Åberg, PhD, is a Senior Researcher; Kristian Björnstad, PhD, is a Senior Researcher; and Mikael Hedeland, PhD, is an Associate Professor and Deputy Head of Department; all at the Department of Chemistry, Environment and Feed Hygiene, National Veterinary Institute (SVA), Uppsala, Sweden. Dr. Åberg and Dr. Hedeland are also affiliated with the Division of Analytical Pharmaceutical Chemistry, Uppsala University, Uppsala, Sweden
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30
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Chang HH, Wang TP, Chen PK, Lin YY, Liao CH, Lin TK, Chiang YW, Lin WB, Chiang CY, Kau JH, Huang HH, Hsu HL, Liao CY, Sun DS. Erythropoiesis suppression is associated with anthrax lethal toxin-mediated pathogenic progression. PLoS One 2013; 8:e71718. [PMID: 23977125 PMCID: PMC3747219 DOI: 10.1371/journal.pone.0071718] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 07/01/2013] [Indexed: 01/01/2023] Open
Abstract
Anthrax is a disease caused by the bacterium Bacillus anthracis, which results in high mortality in animals and humans. Although some of the mechanisms are already known such as asphyxia, extensive knowledge of molecular pathogenesis of this disease is deficient and remains to be further investigated. Lethal toxin (LT) is a major virulence factor of B. anthracis and a specific inhibitor/protease of mitogen-activated protein kinase kinases (MAPKKs). Anthrax LT causes lethality and induces certain anthrax-like symptoms, such as anemia and hypoxia, in experimental mice. Mitogen-activated protein kinases (MAPKs) are the downstream pathways of MAPKKs, and are important for erythropoiesis. This prompted us to hypothesize that anemia and hypoxia may in part be exacerbated by erythropoietic dysfunction. As revealed by colony-forming cell assays in this study, LT challenges significantly reduced mouse erythroid progenitor cells. In addition, in a proteolytic activity-dependent manner, LT suppressed cell survival and differentiation of cord blood CD34+-derived erythroblasts in vitro. Suppression of cell numbers and the percentage of erythroblasts in the bone marrow were detected in LT-challenged C57BL/6J mice. In contrast, erythropoiesis was provoked through treatments of erythropoietin, significantly ameliorating the anemia and reducing the mortality of LT-treated mice. These data suggested that suppressed erythropoiesis is part of the pathophysiology of LT-mediated intoxication. Because specific treatments to overcome LT-mediated pathogenesis are still lacking, these efforts may help the development of effective treatments against anthrax.
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Affiliation(s)
- Hsin-Hou Chang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Tsung-Pao Wang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Po-Kong Chen
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Yo-Yin Lin
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Hsien Liao
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ting-Kai Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Ya-Wen Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Wen-Bin Lin
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Chih-Yu Chiang
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
| | - Jyh-Hwa Kau
- Department of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan
| | - Hsin-Hsien Huang
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Hui-Ling Hsu
- Institute of Preventive Medicine, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Yuan Liao
- Department of Obstetrics and Gynecology, Mennonite Christian HospitalHualien, Taiwan
| | - Der-Shan Sun
- Department of Molecular Biology and Human Genetics, Tzu-Chi University, Hualien, Taiwan
- Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan
- * E-mail:
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Evaluation of immunogenicity and efficacy of anthrax vaccine adsorbed for postexposure prophylaxis. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2013; 20:1016-26. [PMID: 23658392 DOI: 10.1128/cvi.00099-13] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Antimicrobials administered postexposure can reduce the incidence or progression of anthrax disease, but they do not protect against the disease resulting from the germination of spores that may remain in the body after cessation of the antimicrobial regimen. Such additional protection may be achieved by postexposure vaccination; however, no anthrax vaccine is licensed for postexposure prophylaxis (PEP). In a rabbit PEP study, animals were subjected to lethal challenge with aerosolized Bacillus anthracis spores and then were treated with levofloxacin with or without concomitant intramuscular (i.m.) vaccination with anthrax vaccine adsorbed (AVA) (BioThrax; Emergent BioDefense Operations Lansing LLC, Lansing, MI), administered twice, 1 week apart. A significant increase in survival rates was observed among vaccinated animals compared to those treated with antibiotic alone. In preexposure prophylaxis studies in rabbits and nonhuman primates (NHPs), animals received two i.m. vaccinations 1 month apart and were challenged with aerosolized anthrax spores at day 70. Prechallenge toxin-neutralizing antibody (TNA) titers correlated with animal survival postchallenge and provided the means for deriving an antibody titer associated with a specific probability of survival in animals. In a clinical immunogenicity study, 82% of the subjects met or exceeded the prechallenge TNA value that was associated with a 70% probability of survival in rabbits and 88% probability of survival in NHPs, which was estimated based on the results of animal preexposure prophylaxis studies. The animal data provide initial information on protective antibody levels for anthrax, as well as support previous findings regarding the ability of AVA to provide added protection to B. anthracis-infected animals compared to antimicrobial treatment alone.
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Bozue J, Powell BS, Cote CK, Moody KL, Gelhaus HC, Vietri NJ, Rozak DA. Disrupting the luxS quorum sensing gene does not significantly affect Bacillus anthracis virulence in mice or guinea pigs. Virulence 2012; 3:504-9. [PMID: 23076278 PMCID: PMC3524149 DOI: 10.4161/viru.21934] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Many bacterial species use secreted quorum-sensing autoinducer molecules to regulate cell density- and growth phase-dependent gene expression, including virulence factor production, as sufficient environmental autoinducer concentrations are achieved. Bacillus anthracis, the causative agent of anthrax, contains a functional autoinducer (AI-2) system, which appears to regulate virulence gene expression. To determine if the AI-2 system is necessary for disease, we constructed a LuxS AI-2 synthase-deficient mutant in the virulent Ames strain of B. anthracis. We found that growth of the LuxS-deficient mutant was inhibited and sporulation was delayed when compared with the parental strain. However, spores of the Ames luxS mutant remained fully virulent in both mice and guinea pigs.
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Affiliation(s)
- Joel Bozue
- The United States Army of Medical Research Institute of Infectious Diseases, Fort Detrick, MD, USA.
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33
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Panning of a phage display library against a synthetic capsule for peptide ligands that bind to the native capsule of Bacillus anthracis. PLoS One 2012; 7:e45472. [PMID: 23029033 PMCID: PMC3446873 DOI: 10.1371/journal.pone.0045472] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 08/17/2012] [Indexed: 11/19/2022] Open
Abstract
Bacillus anthracis is the causative agent of anthrax with the ability to not only produce a tripartite toxin, but also an enveloping capsule comprised primarily of γ-D-glutamic acid residues. The purpose of this study was to isolate peptide ligands capable of binding to the native capsule of B. anthracis from a commercial phage display peptide library using a synthetic form of the capsule consisting of 12 γ-D-glutamic acid residues. Following four rounds of selection, 80 clones were selected randomly and analysed by DNA sequencing. Four clones, each containing a unique consensus sequence, were identified by sequence alignment analysis. Phage particles were prepared and their derived 12-mer peptides were also chemically synthesized and conjugated to BSA. Both the phage particles and free peptide-BSA conjugates were evaluated by ELISA for binding to encapsulated cells of B. anthracis as well as a B. anthracis capsule extract. All the phage particles tested except one were able to bind to both the encapsulated cells and the capsule extract. However, the peptide-BSA conjugates could only bind to the encapsulated cells. One of the peptide-BSA conjugates, with the sequence DSSRIPMQWHPQ (termed G1), was fluorescently labelled and its binding to the encapsulated cells was further confirmed by confocal microscopy. The results demonstrated that the synthetic capsule was effective in isolating phage-displayed peptides with binding affinity for the native capsule of B. anthracis.
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34
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Neutralization of B. anthracis toxins during ex vivo phagocytosis. Glycoconj J 2012; 30:473-84. [PMID: 22983705 DOI: 10.1007/s10719-012-9446-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 08/26/2012] [Accepted: 08/27/2012] [Indexed: 10/27/2022]
Abstract
Glycoconjugates (GCs) are recognized as stimulation and signaling agents, affecting cell adhesion, activation, and growth of living organisms. Among GC targets, macrophages are considered ideal since they play a central role in inflammation and immune responses against foreign agents. In this context, we studied the effects of highly selective GCs in neutralizing toxin factors produced by B. anthracis during phagocytosis using murine macrophages. The effects of GCs were studied under three conditions: A) prior to, B) during, and C) following exposure of macrophages to B. anthracis individual toxin (protective antigen [PA], edema factor [EF], lethal factor [LF] or toxin complexes (PA-EF-LF, PA-EF, and PA-LF). We employed ex vivo phagocytosis and post-phagocytosis analysis including direct microscopic observation of macrophage viability, and macrophage activation. Our results demonstrated that macrophages are more prone to adhere to GC-altered PA-EF-LF, PA-EF, and PA-LF toxin complexes. This adhesion results in a higher phagocytosis rate and toxin complex neutralization during phagocytosis. In addition, GCs enhance macrophage viability, activate macrophages, and stimulate nitric oxide (NO) production. The present study may be helpful in identifying GC ligands with toxin-neutralizing and/or immunomodulating properties. In addition, our study could suggest GCs as new targets for existing vaccines and the prospective development of vaccines and immunomodulators used to combat the effects of B. anthracis.
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Abstract
Having access to mild and operationally simple techniques for attaining carbohydrate targets will be necessary to facilitate advancement in biological, medicinal, and pharmacological research. Even with the abundance of elegant reports for generating glycosidic linkages, stereoselective construction of α- and β-oligosaccharides and glycoconjugates is by no means trivial. In an era where expanded awareness of the impact we are having on the environment drives the state-of-the-art, synthetic chemists are tasked with developing cleaner and more efficient reactions for achieving their transformations. This movement imparts the value that prevention of waste is always superior to its treatment or cleanup. This review will highlight recent advancement in this regard by examining strategies that employ transition metal catalysis in the synthesis of oligosaccharides and glycoconjugates. These methods are mild and effective for constructing glycosidic bonds with reduced levels of waste through utilization of sub-stoichiometric amounts of transition metals to promote the glycosylation.
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Affiliation(s)
- Matthew J. McKay
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Hien M. Nguyen
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
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Göttle M, Dove S, Seifert R. Bacillus anthracis edema factor substrate specificity: evidence for new modes of action. Toxins (Basel) 2012; 4:505-35. [PMID: 22852066 PMCID: PMC3407890 DOI: 10.3390/toxins4070505] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 06/15/2012] [Accepted: 06/27/2012] [Indexed: 12/20/2022] Open
Abstract
Since the isolation of Bacillus anthracis exotoxins in the 1960s, the detrimental activity of edema factor (EF) was considered as adenylyl cyclase activity only. Yet the catalytic site of EF was recently shown to accomplish cyclization of cytidine 5'-triphosphate, uridine 5'-triphosphate and inosine 5'-triphosphate, in addition to adenosine 5'-triphosphate. This review discusses the broad EF substrate specificity and possible implications of intracellular accumulation of cyclic cytidine 3':5'-monophosphate, cyclic uridine 3':5'-monophosphate and cyclic inosine 3':5'-monophosphate on cellular functions vital for host defense. In particular, cAMP-independent mechanisms of action of EF on host cell signaling via protein kinase A, protein kinase G, phosphodiesterases and CNG channels are discussed.
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Affiliation(s)
- Martin Göttle
- Department of Neurology, Emory University School of Medicine, 6302 Woodruff Memorial Research Building, 101 Woodruff Circle, Atlanta, GA 30322, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-404-727-1678; Fax: +1-404-727-3157
| | - Stefan Dove
- Department of Medicinal/Pharmaceutical Chemistry II, University of Regensburg, D-93040 Regensburg, Germany;
| | - Roland Seifert
- Institute of Pharmacology, Medical School of Hannover, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany;
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Klezovich-Bénard M, Corre JP, Jusforgues-Saklani H, Fiole D, Burjek N, Tournier JN, Goossens PL. Mechanisms of NK cell-macrophage Bacillus anthracis crosstalk: a balance between stimulation by spores and differential disruption by toxins. PLoS Pathog 2012; 8:e1002481. [PMID: 22253596 PMCID: PMC3257302 DOI: 10.1371/journal.ppat.1002481] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 11/28/2011] [Indexed: 01/08/2023] Open
Abstract
NK cells are important immune effectors for preventing microbial invasion and dissemination, through natural cytotoxicity and cytokine secretion. Bacillus anthracis spores can efficiently drive IFN-γ production by NK cells. The present study provides insights into the mechanisms of cytokine and cellular signaling that underlie the process of NK-cell activation by B. anthracis and the bacterial strategies to subvert and evade this response. Infection with non-toxigenic encapsulated B. anthracis induced recruitment of NK cells and macrophages into the mouse draining lymph node. Production of edema (ET) or lethal (LT) toxin during infection impaired this cellular recruitment. NK cell depletion led to accelerated systemic bacterial dissemination. IFN-γ production by NK cells in response to B. anthracis spores was: i) contact-dependent through RAE-1-NKG2D interaction with macrophages; ii) IL-12, IL-18, and IL-15-dependent, where IL-12 played a key role and regulated both NK cell and macrophage activation; and iii) required IL-18 for only an initial short time window. B. anthracis toxins subverted both NK cell essential functions. ET and LT disrupted IFN-γ production through different mechanisms. LT acted both on macrophages and NK cells, whereas ET mainly affected macrophages and did not alter NK cell capacity of IFN-γ secretion. In contrast, ET and LT inhibited the natural cytotoxicity function of NK cells, both in vitro and in vivo. The subverting action of ET thus led to dissociation in NK cell function and blocked natural cytotoxicity without affecting IFN-γ secretion. The high efficiency of this process stresses the impact that this toxin may exert in anthrax pathogenesis, and highlights a potential usefulness for controlling excessive cytotoxic responses in immunopathological diseases. Our findings therefore exemplify the delicate balance between bacterial stimulation and evasion strategies. This highlights the potential implication of the crosstalk between host innate defences and B. anthracis in initial anthrax control mechanisms. NK cells are important immune effectors that perform a surveillance task and react to transformed, stressed, and virally infected cells. They represent a first-line defence against cancer and pathogen invasion. Different pathogens trigger distinct NK-cell activation pathways. The Bacillus anthracis spore is the highly resistant form that enters the host and provokes anthrax. This microbe kills through a combination of acute bacterial infection and devastating toxemia. In the present study, we characterise the crosstalk between NK cells and spores, as well as the strategies used by B. anthracis to evade initial control mechanisms and impact anthrax pathogenesis. Our findings exemplify the spores' property to efficiently drive a high production of IFN-γ by NK cells, as well as the complex pathways used for activation which require both cytokine and cellular signaling. B. anthracis subverts this response through its toxins by paralysing essential NK cell functions. Furthermore, edema toxin from B. anthracis blocks natural cytotoxicity without affecting IFN-γ secretion. The CyaA toxin of Bordetella pertussis possesses the same enzymatic activity and has a similar effect. The high efficiency of these toxins in blocking cytotoxicity in vivo implies possible exploitation of their subverting activity to modulate excessive cytotoxic responses in immunopathological diseases.
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MESH Headings
- Animals
- Bacillus anthracis/immunology
- Bacterial Toxins/pharmacology
- Cells, Cultured
- Female
- Homeostasis/drug effects
- Homeostasis/immunology
- Immunity, Cellular/drug effects
- Immunity, Cellular/immunology
- Killer Cells, Natural/drug effects
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- Macrophage Activation/drug effects
- Macrophage Activation/immunology
- Macrophages/drug effects
- Macrophages/immunology
- Macrophages/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptor Cross-Talk/drug effects
- Receptor Cross-Talk/immunology
- Spores, Bacterial/immunology
- Spores, Bacterial/physiology
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Affiliation(s)
- Maria Klezovich-Bénard
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | - Jean-Philippe Corre
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | | | - Daniel Fiole
- Unité Interactions Hôte-Agents Pathogènes, Département de Microbiologie, Institut de Recherche Biomédicale des Armées, La Tronche, France
- Laboratoire Interdisciplinaire de Physique, UMR 5588 CNRS/Université Joseph Fourier, St-Martin-d'Hères, France
| | - Nick Burjek
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
| | - Jean-Nicolas Tournier
- Unité Interactions Hôte-Agents Pathogènes, Département de Microbiologie, Institut de Recherche Biomédicale des Armées, La Tronche, France
- École du Val-de-Grâce, Paris, France
| | - Pierre L. Goossens
- Laboratoire Pathogénie et Toxi-Infections Bactériennes, Institut Pasteur, Paris, France
- CNRS URA 2172, Paris, France
- * E-mail:
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Rameshwar P, Wong EW, Connell ND. Effects by anthrax toxins on hematopoiesis: a key role for cytokines as mediators. Cytokine 2011; 57:143-9. [PMID: 22082805 DOI: 10.1016/j.cyto.2011.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 09/27/2011] [Accepted: 10/20/2011] [Indexed: 01/03/2023]
Abstract
An understanding of anthrax toxins on the emerging immune system and blood production are significant to medicine. This study examined the effects of anthrax toxin on hematopoiesis and determined roles for cytokines. Anthrax holotoxin toxin is three components: protective antigen (PA) binds to the target cell and mediates the entry of lethal factor (LF) and edema factor (EF). Anthrax toxin dramatically inhibits signaling in immune cells. We first identified the cell subsets that interacted with the protective antigen (PA) and then studied the effects on hematopoietic progenitors in clonogenic assays: granulocytic-monocytic (CFU-GM) and late erythroid (CFU-E). Multi-color immunofluorescence with FITC-PA indicated its interaction with early and late myeloid cells. Clonogenic assays, in the presence or absence of holotoxin and individual toxin proteins resulted in significant suppression by hologenic toxic alone, despite the presence of growth-promoting cytokines. Antibodies to anthrax receptor (ATR1) reversed the suppressive effects, indicating specificity. Monomeric proteins showed different effects on myeloid and erythroid progenitors. Suppression was not due to cell death, based on undetectable active caspase 3. Cytokine array analyses with supernatants from toxin-stimulated stroma showed an increase in the hematopoietic suppressor, MIP-1α. This finding, in addition to our previous studies, showing an increase in IL-10, suggested indirect roles for cytokines in toxin-mediated hematopoietic suppression. The chemokine, SDF-1α was increased. Since SDF-1 is involved in the mobilization of hematopoietic cells, it is likely that anthrax holotoxin could induce cell exit from BM. In summary, anthrax holotoxin, but not individual toxins, exerted hematopoietic effects on myeloid and erythroid progenitors via specific receptor, partly through the induction of cytokines.
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Affiliation(s)
- Pranela Rameshwar
- Department of Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA.
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39
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Mechanism of lethal toxin neutralization by a human monoclonal antibody specific for the PA(20) region of Bacillus anthracis protective antigen. Toxins (Basel) 2011; 3:979-90. [PMID: 22069752 PMCID: PMC3202870 DOI: 10.3390/toxins3080979] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/07/2011] [Accepted: 08/04/2011] [Indexed: 11/17/2022] Open
Abstract
The primary immunogenic component of the currently approved anthrax vaccine is the protective antigen (PA) unit of the binary toxin system. PA-specific antibodies neutralize anthrax toxins and protect against infection. Recent research has determined that in humans, only antibodies specific for particular determinants are capable of effecting toxin neutralization, and that the neutralizing epitopes recognized by these antibodies are distributed throughout the PA monomer. The mechanisms by which the majority of these epitopes effect neutralization remain unknown. In this report we investigate the process by which a human monoclonal antibody specific for the amino-terminal domain of PA neutralizes lethal toxin in an in vitro assay of cytotoxicity, and find that it neutralizes LT by blocking the requisite cleavage of the amino-terminal 20 kD portion of the molecule (PA20) from the remainder of the PA monomer. We also demonstrate that the epitope recognized by this human monoclonal does not encompass the 166RKKR169 furin recognition sequence in domain 1 of PA.
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40
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Lawrence WS, Marshall JR, Zavala DL, Weaver LE, Baze WB, Moen ST, Whorton EB, Gourley RL, Peterson JW. Hemodynamic effects of anthrax toxins in the rabbit model and the cardiac pathology induced by lethal toxin. Toxins (Basel) 2011; 3:721-36. [PMID: 22069736 PMCID: PMC3202836 DOI: 10.3390/toxins3060721] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2011] [Revised: 06/11/2011] [Accepted: 06/21/2011] [Indexed: 01/13/2023] Open
Abstract
Anthrax lethal toxin (LeTx) and edema toxin (EdTx) have been shown to alter hemodynamics in the rodent model, while LeTx primarily is reported to induce extensive tissue pathology. However, the rodent model has limitations when used for comparison to higher organisms such as humans. The rabbit model, on the other hand, has gained recognition as a useful model for studying anthrax infection and its pathophysiological effects. In this study, we assessed the hemodynamic effects of lethal toxin (LeTx) and edema toxin (EdTx) in the rabbit model using physiologically relevant amounts of the toxins. Moreover, we further examine the pathological effects of LeTx on cardiac tissue. We intravenously injected Dutch-belted rabbits with either low-dose and high-dose recombinant LeTx or a single dose of EdTx. The animals’ heart rate and mean arterial pressure were continuously monitored via telemetry until either 48 or 72 h post-challenge. Additional animals challenged with LeTx were used for cardiac troponin I (cTnI) quantitation, cardiac histopathology, and echocardiography. LeTx depressed heart rate at the lower dose and mean arterial pressure (MAP) at the higher dose. EdTx, on the other hand, temporarily intensified heart rate while lowering MAP. Both doses of LeTx caused cardiac pathology with the higher dose having a more profound effect. Lastly, left-ventricular dilation due to LeTx was not apparent at the given time-points. Our study demonstrates the hemodynamic effects of anthrax toxins, as well as the pathological effects of LeTx on the heart in the rabbit model, and it provides further evidence for the toxins’ direct impact on the heart.
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Affiliation(s)
- William S Lawrence
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston/TX 77555, USA.
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Jones MB, Peterson SN, Benn R, Braisted JC, Jarrahi B, Shatzkes K, Ren D, Wood TK, Blaser MJ. Role of luxS in Bacillus anthracis growth and virulence factor expression. Virulence 2011; 1:72-83. [PMID: 21178420 DOI: 10.4161/viru.1.2.10752] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Quorum-sensing (QS), the regulation of bacterial gene expression in response to changes in cell density, involves pathways that synthesize signaling molecules (auto-inducers). The luxS/AI-2-mediated QS system has been identified in both gram-positive and gram-negative bacteria. Bacillus anthracis, the etiological agent of anthrax, possesses genes involved in luxS/AI-2-mediated QS, and deletion of luxS in B. anthracis Sterne strain 34F2 results in inhibition of AI-2 synthesis and a growth defect. In the present study, we created a ΔluxS B. anthracis strain complemented in trans by insertion of a cassette, including luxS and a gene encoding erythromycin resistance, into the truncated plcR regulator locus. The complemented ΔluxS strain has restored AI-2 synthesis and wild-type growth. A B. anthracis microarray study revealed consistent differential gene expression between the wild-type and ΔluxS strain, including downregulation of the B. anthracis S-layer protein gene EA1 and pXO1 virulence genes. These data indicate that B. anthracis may use luxS/AI-2-mediated QS to regulate growth, density-dependent gene expression and virulence factor expression.
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Affiliation(s)
- Marcus B Jones
- Pathogen Functional Genomics Resource Center, J. Craig Venter Institute, Rockville, MD, USA.
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42
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Hao RZ, Song HB, Zuo GM, Yang RF, Wei HP, Wang DB, Cui ZQ, Zhang Z, Cheng ZX, Zhang XE. DNA probe functionalized QCM biosensor based on gold nanoparticle amplification for Bacillus anthracis detection. Biosens Bioelectron 2011; 26:3398-404. [DOI: 10.1016/j.bios.2011.01.010] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 12/21/2010] [Accepted: 01/06/2011] [Indexed: 10/18/2022]
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43
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Thomas J, Epshtein Y, Chopra A, Ordog B, Ghassemi M, Christman JW, Nattel S, Cook JL, Levitan I. Anthrax lethal factor activates K(+) channels to induce IL-1β secretion in macrophages. THE JOURNAL OF IMMUNOLOGY 2011; 186:5236-43. [PMID: 21421849 DOI: 10.4049/jimmunol.1001078] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Anthrax lethal toxin (LeTx) is a virulence factor of Bacilillus anthracis that is a bivalent toxin, containing lethal factor (LF) and protective Ag proteins, which causes cytotoxicity and altered macrophage function. LeTx exposure results in early K(+) efflux from macrophages associated with caspase-1 activation and increased IL-1β release. The mechanism of this toxin-induced K(+) efflux is unknown. The goals of the current study were to determine whether LeTx-induced K(+) efflux from macrophages is mediated by toxin effects on specific K(+) channels and whether altered K(+)-channel activity is involved in LeTx-induced IL-1β release. Exposure of macrophages to LeTx induced a significant increase in the activities of two types of K(+) channels that have been identified in mouse macrophages: Ba(2+)-sensitive inwardly rectifying K(+) (Kir) channels and 4-aminopyridine-sensitive outwardly rectifying voltage-gated K(+) (Kv) channels. LeTx enhancement of both Kir and Kv required the proteolytic activity of LF, because exposure of macrophages to a mutant LF-protein (LF(E687C)) combined with protective Ag protein had no effect on the currents. Furthermore, blocking Kir and Kv channels significantly decreased LeTx-induced release of IL-1β. In addition, retroviral transduction of macrophages with wild-type Kir enhanced LeTx-induced release of IL-1β, whereas transduction of dominant-negative Kir blocked LeTx-induced release of IL-1β. Activation of caspase-1 was not required for LeTx-induced activation of either of the K(+) channels. These data indicate that a major mechanism through which LeTx stimulates macrophages to release IL-1β involves an LF-protease effect that enhances Kir and Kv channel function during toxin stimulation.
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Affiliation(s)
- Johnson Thomas
- Section of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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Bagramyan K, Kalkum M. Ultrasensitive detection of botulinum neurotoxins and anthrax lethal factor in biological samples by ALISSA. Methods Mol Biol 2011; 739:23-36. [PMID: 21567315 DOI: 10.1007/978-1-61779-102-4_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Both botulinum neurotoxins (BoNTs) and anthrax lethal factor, a component of anthrax toxin, exhibit zinc metalloprotease activity. The assay detailed here is capable of quantitatively detecting these proteins by measuring their enzymatic functions with high sensitivity. The detection method encompasses two steps: (1) specific target capture and enrichment and (2) cleavage of a fluorogenic substrate by the immobilized active target, the extent of which is quantitatively determined by differential fluorometry. Because a critical ingredient for the target enrichment is an immobilization matrix made out of hundreds of thousands of microscopic, antibody-coated beads, we have termed this detection method an assay with a large immuno-sorbent surface area (ALISSA). The binding and reaction surface area in the ALISSA is approximately 30-fold larger than in most microtiter plate-based enzyme-linked immunosorbent assays (ELISAs). ALISSA reaches atto (10(-18)) to femto (10(-15)) molar sensitivities for the detection of BoNT serotypes A and E and anthrax lethal factor. In addition, ALISSA provides high specificity in complex biological matrices, such as serum and liquid foods, which may contain various other proteases and hydrolytic enzymes. This methodology can potentially be expanded to many other enzyme targets by selecting appropriate fluorogenic substrates and capture antibodies. Important requirements are that the enzyme remains active after being immobilized by the capture antibody and that the substrate is specifically converted by the immobilized enzyme target at a fast conversion rate.A detailed protocol to conduct ALISSA for the detection and quantification of BoNT serotypes A and E and anthrax lethal factor is described.
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Affiliation(s)
- Karine Bagramyan
- Department of Immunology, The Beckman Research Institute of the City of Hope, Duarte, CA, USA
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45
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Nguyen J, Russell SC. Targeted proteomics approach to species-level identification of Bacillus thuringiensis spores by AP-MALDI-MS. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2010; 21:993-1001. [PMID: 20236838 DOI: 10.1016/j.jasms.2010.01.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 01/28/2010] [Accepted: 01/28/2010] [Indexed: 05/28/2023]
Abstract
Anthrax infections progress at a rapid pace, making rapid detection methods of utmost importance. MALDI-MS proteomics methods focused on Bacillus anthracis detection have targeted chromosomally encoded proteins, which are highly conserved between closely related species, hindering species identification. Presented here is an AP-MALDI-MS method targeting plasmid-borne proteins from Bacillus spores for species-level identification. A bioinformatics analysis revealed that 60.3% and 75.4% of tryptic peptides from plasmid-borne proteins of B. anthracis and B. thuringiensis were species-specific, respectively. Reported here is a method in which plasmid-borne delta-endotoxins were extracted directly from B. thuringiensis spores in 100 mM KOH. The pH was then adjusted to 8 and a 5-min trypsin digestion was performed on the extracted proteins. The resulting tryptic peptides were analyzed by AP-MALDI-MS/MS, which produced a definitive identification the B. thuringiensis species-specific Cry1Ab protein with a MASCOT score of 278 and expect value of 7.5 x 10(-23). This method has demonstrated the detection and identification of B. thuringiensis spores at the species level following a 5-min trypsin digestion. The challenges in applying a similar approach to the detection of plasmid-borne protein toxins from B. anthracis are also discussed.
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Affiliation(s)
- Jennifer Nguyen
- Department of Chemistry, California State University, Stanislaus, Turlock, California 95382-0299, USA
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46
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Lipscomb MF, Hutt J, Lovchik J, Wu T, Lyons CR. The pathogenesis of acute pulmonary viral and bacterial infections: investigations in animal models. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2010; 5:223-52. [PMID: 19824827 DOI: 10.1146/annurev-pathol-121808-102153] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Acute viral and bacterial infections in the lower respiratory tract are major causes of morbidity and mortality worldwide. The proper study of pulmonary infections requires interdisciplinary collaboration among physicians and biomedical scientists to develop rational hypotheses based on clinical studies and to test these hypotheses in relevant animal models. Animal models for common lung infections are essential to understand pathogenic mechanisms and to clarify general mechanisms for host protection in pulmonary infections, as well as to develop vaccines and therapeutics. Animal models for uncommon pulmonary infections, such as those that can be caused by category A biothreat agents, are also very important because the infrequency of these infections in humans limits in-depth clinical studies. This review summarizes our understanding of innate and adaptive immune mechanisms in the lower respiratory tract and discusses how animal models for selected pulmonary pathogens can contribute to our understanding of the pathogenesis of lung infections and to the search for new vaccines and therapies.
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Affiliation(s)
- Mary F Lipscomb
- Departments of Pathology and University of New Mexico School of Medicine, Albuquerque, New Mexico 87131.
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Liu K, Wong EW, Schutzer SE, Connell ND, Upadhyay A, Bryan M, Rameshwar P. Non-canonical effects of anthrax toxins on haematopoiesis: implications for vaccine development. J Cell Mol Med 2008; 13:1907-1919. [PMID: 18752638 DOI: 10.1111/j.1582-4934.2008.00477.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Anthrax receptor (ATR) shares similarities with molecules relevant to haematopoiesis. This suggests that anthrax proteins might bind to these mimicking molecules and exert non-specific haematopoietic effects. The haematopoietic system is the site of immune cell development in the adult. As such, ATR ligand, protective antigen (PA) and the other anthrax proteins, lethal factor, edema factor, could be significant to haematopoietic responses against Bacillus anthracis infection. Because haematopoiesis is the process of immune cell development, effects by anthrax proteins could be relevant to vaccine development. Here, we report on effects of anthrax proteins and toxins on early and late haematopoiesis. Flow cytometry shows binding of PA to haematopoietic cells. This binding might be partly specific because flow cytometry and Western blots demonstrate the presence of ATR1 on haematopoietic cell subsets and the supporting stromal cells. Functional studies with long-term initiating cell and clonogenic assays determined haematopoietic suppression by anthrax toxins and stimulation by monomeric proteins. The suppressive effects were not attributed to cell death, but partly through the induction of haematopoietic suppressors, interleukin (IL)-10 and CCL3 (MIP-1alpha). In summary, anthrax proteins affect immune cell development by effects on haematopoiesis. The type of effect, stimulation or suppression, depend on whether the stimulator is a toxin or monomeric protein. The studies show effects of anthrax proteins beginning at the early stage of haematopoiesis, and also show secondary mediators such as IL-10 and CCL3. The roles of other cytokines and additional ATR are yet to be investigated.
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Affiliation(s)
- Katherine Liu
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
| | - Elaine W Wong
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
| | - Steven E Schutzer
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
| | - Nancy D Connell
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
| | - Alok Upadhyay
- Graduate School of Biomedical Sciences - UMDNJ, Newark Campus, NJ, USA
| | - Margarette Bryan
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
| | - Pranela Rameshwar
- New Jersey Medical School - UMDNJ, Department of Medicine-Hematology/Oncology, Newark, NJ, USA
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48
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In Vitro Screening and In Vivo Analysis of Anthrax Lethal Factor Inhibitor. JOURNAL OF THE KOREAN CHEMICAL SOCIETY-DAEHAN HWAHAK HOE JEE 2008. [DOI: 10.5012/jkcs.2008.52.5.495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Detoxified lethal toxin as a potential mucosal vaccine against anthrax. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2008; 15:612-6. [PMID: 18256208 DOI: 10.1128/cvi.00402-07] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The nontoxic mutant lethal factor (mLF; which has the E687C substitution) and functional protective antigen (PA63) of Bacillus anthracis were evaluated for their use as mucosal vaccines against anthrax in A/J mice. Intranasal vaccination of three doses of 30 microg of mLF or 60 microg of PA63 elicited significant serum and mucosal antibody responses, with anthrax lethal toxin-neutralizing titers of 40 and 60 in immune sera, respectively. However, only 30% and 60% of the vaccinated animals in the two groups could survive a challenge with 100 times the 50% lethal dose of B. anthracis Sterne spores, respectively. In contrast, vaccination with three doses of the combination of 30 microg of mLF and 60 microg of PA63, the detoxified lethal toxin, elicited antibody responses against LF and PA significantly higher than those elicited after vaccination with mLF or PA63 individually by use of the same dose and schedule. Vaccination with the detoxified lethal toxin resulted in significantly higher lethal toxin-neutralizing antibody titers in sera (titer, 90). Animals vaccinated with three doses of the detoxified lethal toxin were completely protected against the spore challenge. The data suggest that mLF and PA63 have a mutual enhancement effect for evoking systemic and mucosal immune responses and that the detoxified lethal toxin can be used as an efficient mucosal vaccine against anthrax.
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Analysis of a novel spore antigen in Bacillus anthracis that contributes to spore opsonization. Microbiology (Reading) 2008; 154:619-632. [DOI: 10.1099/mic.0.2007/008292-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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