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Umarje SC, Banerjee SK. Non-traditional approaches for control of antibiotic resistance. Expert Opin Biol Ther 2023; 23:1113-1135. [PMID: 38007617 DOI: 10.1080/14712598.2023.2279644] [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: 08/28/2023] [Accepted: 11/01/2023] [Indexed: 11/27/2023]
Abstract
INTRODUCTION The drying up of antibiotic pipeline has necessitated the development of alternative therapeutic strategies to control the problem of antimicrobial resistance (AMR) that is expected to kill 10-million people annually by 2050. Newer therapeutic approaches address the shortcomings of traditional small-molecule antibiotics - the lack of specificity, evolvability, and susceptibility to mutation-based resistance. These 'non-traditional' molecules are biologicals having a complex structure and mode(s) of action that makes them resilient to resistance. AREAS COVERED This review aims to provide information about the non-traditional drug development approaches to tackle the problem of antimicrobial resistance, from the pre-antibiotic era to the latest developments. We have covered the molecules under development in the clinic with literature sourced from reviewed scholarly articles, official company websites involved in innovation of concerned therapeutics, press releases from the regulatory bodies, and clinical trial databases. EXPERT OPINION Formal introduction of non-traditional therapies in general practice can be quick and feasible only if supported with companion diagnostics and used in conjunction with established therapies. Owing to relatively higher development costs, non-traditional therapeutics require more funding as well as well as clarity in regulatory and clinical path. We are hopeful these issues are adequately addressed before AMR develops into a pandemic.
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Affiliation(s)
- Siddharth C Umarje
- Department of Proteomics, AbGenics Life Sciences Pvt. Ltd., Pune, India
- AbGenics Life Sciences Pvt. Ltd., Pune, India
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Cavaco M, Castanho MARB, Neves V. The Use of Antibody-Antibiotic Conjugates to Fight Bacterial Infections. Front Microbiol 2022; 13:835677. [PMID: 35330773 PMCID: PMC8940529 DOI: 10.3389/fmicb.2022.835677] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/14/2022] [Indexed: 12/26/2022] Open
Abstract
The emergence of antimicrobial resistance (AMR) is rapidly increasing and it is one of the significant twenty-first century’s healthcare challenges. Unfortunately, the development of effective antimicrobial agents is a much slower and complex process compared to the spread of AMR. Consequently, the current options in the treatment of AMR are limited. One of the main alternatives to conventional antibiotics is the use of antibody-antibiotic conjugates (AACs). These innovative bioengineered agents take advantage of the selectivity, favorable pharmacokinetic (PK), and safety of antibodies, allowing the administration of more potent antibiotics with less off-target effects. Although AACs’ development is challenging due to the complexity of the three components, namely, the antibody, the antibiotic, and the linker, some successful examples are currently under clinical studies.
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Affiliation(s)
- Marco Cavaco
- Faculdade de Medicina, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel A R B Castanho
- Faculdade de Medicina, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
| | - Vera Neves
- Faculdade de Medicina, Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Lisbon, Portugal
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Avril A, Tournier JN, Paucod JC, Fournes B, Thullier P, Pelat T. Antibodies against Anthrax Toxins: A Long Way from Benchlab to the Bedside. Toxins (Basel) 2022; 14:toxins14030172. [PMID: 35324669 PMCID: PMC8955606 DOI: 10.3390/toxins14030172] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 02/01/2023] Open
Abstract
Anthrax is an acute disease caused by the bacterium Bacillus anthracis, and is a potential biowarfare/bioterrorist agent. Its pulmonary form, caused by inhalation of the spores, is highly lethal and is mainly related to injury caused by the toxins secretion. Antibodies neutralizing the toxins of B. anthracis are regarded as promising therapeutic drugs, and two are already approved by the Federal Drug Administration. We developed a recombinant human-like humanized antibody, 35PA83 6.20, that binds the protective antigen and that neutralized anthrax toxins in-vivo in White New Zealand rabbits infected with the lethal 9602 strain by intranasal route. Considering these promising results, the preclinical and clinical phase one development was funded and a program was started. Unfortunately, after 5 years, the preclinical development was cancelled due to industrial and scientific issues. This shutdown underlined the difficulty particularly, but not only, for an academic laboratory to proceed to clinical development, despite the drug candidate being promising. Here, we review our strategy and some preliminary results, and we discuss the issues that led to the no-go decision of the pre-clinical development of 35PA83 6.20 mAb. Our review provides general information to the laboratories planning a (pre-)clinical development.
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Affiliation(s)
- Arnaud Avril
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; (J.-N.T.); (J.-C.P.); (P.T.); (T.P.)
- Correspondence: ; Tel.: +33-(0)-1-78-65-10-72
| | - Jean-Nicolas Tournier
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; (J.-N.T.); (J.-C.P.); (P.T.); (T.P.)
- Ecole du Val-de-Grâce, 75005 Paris, France
| | - Jean-Charles Paucod
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; (J.-N.T.); (J.-C.P.); (P.T.); (T.P.)
| | - Bénédicte Fournes
- Laboratoire Français du Fractionnement et des Biotechnologies, 91940 Les Ulis, France;
| | - Philippe Thullier
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; (J.-N.T.); (J.-C.P.); (P.T.); (T.P.)
| | - Thibaut Pelat
- Département Microbiologie et Maladies Infectieuses, Institut de Recherche Biomédicale des Armées, 91220 Brétigny-sur-Orge, France; (J.-N.T.); (J.-C.P.); (P.T.); (T.P.)
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Firstova VV, Shakhova AS, Riabko AK, Silkina MV, Zeninskaya NA, Romanenko YO, Marin MA, Rogozin MM, Kartseva AS, Dyatlov IA, Shemyakin IG. Characterization of the adaptive immune response of donors receiving live anthrax vaccine. PLoS One 2021; 16:e0260202. [PMID: 34928976 PMCID: PMC8687594 DOI: 10.1371/journal.pone.0260202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 11/04/2021] [Indexed: 11/19/2022] Open
Abstract
Live anthrax vaccine containing spores from attenuated strains STI-1 of Bacillus anthracis is used in Russia and former CIS (Commonwealth of Independent States) to prevent anthrax. In this paper we studied the duration of circulation of antibodies specific to spore antigens, the protective antigen (PA), the lethal factor (LF) and their domains (D) in donors’ blood at different times after their immunization with live anthrax vaccine. The relationship between the toxin neutralization activity level and the level of antibodies to PA, LF and their domains was tested. The effect of age, gender and number of vaccinations on the level of adaptive post-vaccination immune response has been studied. It was shown that antibodies against PA-D1 circulate in the blood of donors for 1 year or more after immunization with live anthrax vaccine. Antibodies against all domains of LF and PA-D4 were detected in 11 months after vaccination. Antibodies against the spores were detected in 8 months after vaccination. A moderate positive correlation was found between the titers of antibodies to PA, LF, or their domains, and the TNA of the samples of blood serum from the donors.
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Affiliation(s)
- Victoria V. Firstova
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Anastasia S. Shakhova
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Alena K. Riabko
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
- * E-mail:
| | - Marina V. Silkina
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Natalia A. Zeninskaya
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Yana O. Romanenko
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Maksim A. Marin
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Methun M. Rogozin
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Alena S. Kartseva
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Ivan A. Dyatlov
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
| | - Igor G. Shemyakin
- Laboratory of Molecular Biology, Federal Budget Institution of Science «State Research Center for Applied Microbiology and Biotechnology» of Federal Service of Consumer Right Surveillance & Human Welfare, Ministry of Health & Welfare, Obolensk, Moscow Region, Russian Federation
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Progress towards the Development of a NEAT Vaccine for Anthrax II: Immunogen Specificity and Alum Effectiveness in an Inhalational Model. Infect Immun 2020; 88:IAI.00082-20. [PMID: 32393506 DOI: 10.1128/iai.00082-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/23/2020] [Indexed: 12/24/2022] Open
Abstract
Bacillus anthracis is the causative agent of anthrax disease, presents with high mortality, and has been at the center of bioweapon efforts. The only currently U.S. FDA-approved vaccine to prevent anthrax in humans is anthrax vaccine adsorbed (AVA), which is protective in several animal models and induces neutralizing antibodies against protective antigen (PA), the cell-binding component of anthrax toxin. However, AVA requires a five-course regimen to induce immunity, along with an annual booster, and is composed of undefined culture supernatants from a PA-secreting strain. In addition, it appears to be ineffective against strains that lack anthrax toxin. Here, we investigated a vaccine formulation consisting of recombinant proteins from a surface-localized heme transport system containing near-iron transporter (NEAT) domains and its efficacy as a vaccine for anthrax disease. The cocktail of five NEAT domains was protective against a lethal challenge of inhaled bacillus spores at 3 and 28 weeks after vaccination. The reduction of the formulation to three NEATs (IsdX1, IsdX2, and Bslk) was as effective as a five-NEAT domain cocktail. The adjuvant alum, approved for use in humans, was as protective as Freund's Adjuvant, and protective vaccination correlated with increased anti-NEAT antibody reactivity and reduced bacterial levels in organs. Finally, the passive transfer of anti-NEAT antisera reduced mortality and disease severity, suggesting the protective component is comprised of antibodies. Collectively, these results provide evidence that a vaccine based upon recombinant NEAT proteins should be considered in the development of a next-generation anthrax vaccine.
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Human monoclonal anti-protective antigen antibody for the low-dose post-exposure prophylaxis and treatment of Anthrax. BMC Infect Dis 2018; 18:640. [PMID: 30526504 PMCID: PMC6288905 DOI: 10.1186/s12879-018-3542-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 11/23/2018] [Indexed: 12/21/2022] Open
Abstract
Background Disease caused by Bacillus anthracis is often accompanied by high mortality primarily due to toxin-mediated injury. In the early disease course, anthrax toxins are secreted; thus, antibiotic use is limited to the early stage. In this regard, antibodies against the toxin component, protective antigen (PA), play an important role in protecting against anthrax. Therefore, we developed PA21, a fully human anti-PA immunoglobulin G monoclonal antibody. Methods Combining human Fab was screened from a phage library with human heavy constant regions. Enzyme-linked immune sorbent assay, Western blot analysis and immunoprecipitation test evaluated the binding ability of PA21. Moreover, the affinity and neutralizing activity of the antibody was detected in vitro while the protective effectiveness in 60 rats was also examined in vivo. Results The Fischer 344 rats challenged with the lethal toxin can be protected by PA21 at a concentration of 0.067 mg/kg. All six rats remained alive although PA21 was injected 24 h before the toxin challenge. PA21 did not influence the binding of PA to cell receptors and that of a lethal factor to PA. Conclusion The PA21 monoclonal antibody against PA can be used for emergency prophylaxis and anthrax treatment.
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Avril A. Therapeutic Antibodies for Biodefense. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1053:173-205. [PMID: 29549640 DOI: 10.1007/978-3-319-72077-7_9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Diseases can be caused naturally by biological agents such as bacteria, viruses and toxins (natural risk). However, such biological agents can be intentionally disseminated in the environment by a State (military context) or terrorists to cause diseases in a population or livestock, to destabilize a nation by creating a climate of terror, destabilizing the economy and undermining institutions. Biological agents can be classified according to the severity of illness they cause, its mortality and how easily the agent can be spread. The Centers for Diseases Control and Prevention (CDC) classify biological agents in three categories (A, B and C); Category A consists of the six pathogens most suitable for use as bioweapons (Bacillus anthracis, Yersinia pestis, Francisella tularensis, botulinum neurotoxins, smallpox and viral hemorrhagic fevers). Antibodies represent a perfect biomedical countermeasure as they present both prophylactic and therapeutic properties, act fast and are highly specific to the target. This review focuses on the main biological agents that could be used as bioweapons, the history of biowarfare and antibodies that have been developed to neutralize these agents.
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Affiliation(s)
- Arnaud Avril
- Département des maladies infectieuses, Unité biothérapies anti-infectieuses et immunité, Institut de Recherche Biomédical des Armées, Brétigny-sur-Orge, France.
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Wang-Lin SX, Balthasar JP. Pharmacokinetic and Pharmacodynamic Considerations for the Use of Monoclonal Antibodies in the Treatment of Bacterial Infections. Antibodies (Basel) 2018; 7:antib7010005. [PMID: 31544858 PMCID: PMC6698815 DOI: 10.3390/antib7010005] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/01/2018] [Accepted: 01/02/2018] [Indexed: 12/17/2022] Open
Abstract
Antibiotic-resistant bacterial pathogens are increasingly implicated in hospital- and community-acquired infections. Recent advances in monoclonal antibody (mAb) production and engineering have led to renewed interest in the development of antibody-based therapies for treatment of drug-resistant bacterial infections. Currently, there are three antibacterial mAb products approved by the Food and Drug Administration (FDA) and at least nine mAbs are in clinical trials. Antibacterial mAbs are typically developed to kill bacteria or to attenuate bacterial pathological activity through neutralization of bacterial toxins and virulence factors. Antibodies exhibit distinct pharmacological mechanisms from traditional antimicrobials and, hence, cross-resistance between small molecule antimicrobials and antibacterial mAbs is unlikely. Additionally, the long biological half-lives typically found for mAbs may allow convenient dosing and vaccine-like prophylaxis from infection. However, the high affinity of mAbs and the involvement of the host immune system in their pharmacological actions may lead to complex and nonlinear pharmacokinetics and pharmacodynamics. In this review, we summarize the pharmacokinetics and pharmacodynamics of the FDA-approved antibacterial mAbs and those are currently in clinical trials. Challenges in the development of antibacterial mAbs are also discussed.
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Affiliation(s)
- Shun Xin Wang-Lin
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14214, USA.
| | - Joseph P Balthasar
- Department of Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14214, USA.
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Wycoff K, Maclean J, Belle A, Yu L, Tran Y, Roy C, Hayden F. Anti-infective immunoadhesins from plants. PLANT BIOTECHNOLOGY JOURNAL 2015; 13:1078-93. [PMID: 26242703 PMCID: PMC4749143 DOI: 10.1111/pbi.12441] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 06/24/2015] [Accepted: 06/27/2015] [Indexed: 05/22/2023]
Abstract
Immunoadhesins are recombinant proteins that combine the ligand-binding region of a receptor or adhesion molecule with immunoglobulin constant domains. All FDA-approved immunoadhesins are designed to modulate the interaction of a human receptor with its normal ligand, such as Etanercept (Enbrel(®) ), which interferes with the binding of tumour necrosis factor (TNF) to the TNF-alpha receptor and is used to treat inflammatory diseases such as rheumatoid arthritis. Like antibodies, immunoadhesins have long circulating half-lives, are readily purified by affinity-based methods and have the avidity advantages conferred by bivalency. Immunoadhesins that incorporate normal cellular receptors for viruses or bacterial toxins hold great, but as yet unrealized, potential for treating infectious disease. As decoy receptors, immunoadhesins have potential advantages over pathogen-targeted monoclonal antibodies. Planet Biotechnology has specialized in developing anti-infective immunoadhesins using plant expression systems. An immunoadhesin incorporating the cellular receptor for anthrax toxin, CMG2, potently blocks toxin activity in vitro and protects animals against inhalational anthrax. An immunoadhesin based on the receptor for human rhinovirus, ICAM-1, potently blocks infection of human cells by one of the major causes of the common cold. An immunoadhesin targeting the MERS coronavirus is in an early stage of development. We describe here the unique challenges involved in designing and developing immunoadhesins targeting infectious diseases in the hope of inspiring further research into this promising class of drugs.
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Affiliation(s)
| | | | | | - Lloyd Yu
- Planet Biotechnology Inc., Hayward, CA, USA
| | - Y Tran
- Planet Biotechnology Inc., Hayward, CA, USA
| | - Chad Roy
- Tulane National Primate Research Center, Covington, LA, USA
| | - Frederick Hayden
- University of Virginia School of Medicine, Charlottesville, VA, USA
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Yang NJ, Liu DV, Sklaviadis D, Gui DY, Vander Heiden MG, Wittrup KD. Antibody-mediated neutralization of perfringolysin o for intracellular protein delivery. Mol Pharm 2015; 12:1992-2000. [PMID: 25881713 PMCID: PMC4876977 DOI: 10.1021/mp500797n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Perfringolysin O (PFO) is a member of the cholesterol-dependent cytolysin (CDC) family of bacterial pore-forming proteins, which are highly efficient in delivering exogenous proteins to the cytoplasm. However, the indiscriminate and potent cytotoxicity of PFO limits its practical use as an intracellular delivery system. In this study, we describe the design and engineering of a bispecific, neutralizing antibody against PFO, which targets reversibly attenuated PFO to endocytic compartments via receptor-mediated internalization. This PFO-based system efficiently mediated the endosomal release of a co-targeted gelonin construct with high specificity and minimal toxicity in vitro. Consequently, the therapeutic window of PFO was improved by more than 5 orders of magnitude. Our results demonstrating that the activity of pore-forming proteins can be controlled by antibody-mediated neutralization present a novel strategy for utilizing these potent membrane-lytic agents as a safe and effective intracellular delivery vehicle.
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Affiliation(s)
- Nicole J. Yang
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - David V. Liu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Demetra Sklaviadis
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Dan Y. Gui
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Matthew G. Vander Heiden
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, United States
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - K. Dane Wittrup
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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Evaluation of anthrax vaccine safety in 18 to 20 year olds: A first step towards age de-escalation studies in adolescents. Vaccine 2015; 33:2470-6. [DOI: 10.1016/j.vaccine.2015.03.071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 03/02/2015] [Accepted: 03/24/2015] [Indexed: 11/18/2022]
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Ohanjanian L, Remy KE, Li Y, Cui X, Eichacker PQ. An overview of investigational toxin-directed therapies for the adjunctive management of Bacillus anthracis infection and sepsis. Expert Opin Investig Drugs 2015; 24:851-65. [PMID: 25920540 DOI: 10.1517/13543784.2015.1041587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
INTRODUCTION Sepsis with Bacillus anthracis infection has a very high mortality rate despite appropriate antibiotic and supportive therapies. Over the past 15 years, recent outbreaks in the US and in Europe, coupled with anthrax's bioterrorism weapon potential, have stimulated efforts to develop adjunctive therapies to improve clinical outcomes. Since lethal toxin and edema toxin (LT and ET) make central contributions to the pathogenesis of B. anthracis, these have been major targets in this effort. AREAS COVERED Here, the authors review different investigative biopharmaceuticals that have been recently identified for their therapeutic potential as inhibitors of LT or ET. Among these inhibitors are two antibody preparations that have been included in the Strategic National Stockpile (SNS) and several more that have reached Phase I testing. Presently, however, many of these candidate agents have only been studied in vitro and very few tested in bacteria-challenged models. EXPERT OPINION Although a large number of drugs have been identified as potential therapeutic inhibitors of LT and ET, in most cases their testing has been limited. The use of the two SNS antibody therapies during a large-scale exposure to B. anthracis will be difficult. Further testing and development of agents with oral bioavailability and relatively long shelf lives should be a focus for future research.
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Affiliation(s)
- Lernik Ohanjanian
- National Institutes of Health, Clinical Center, Critical Care Medicine Department , Building 10, Room 2C145, Bethesda, MD 20892 , USA +1 301 402 2914 ; +1 301 402 1213 ;
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Generation and Characterization of Human Monoclonal Antibodies Targeting Anthrax Protective Antigen following Vaccination with a Recombinant Protective Antigen Vaccine. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:553-60. [PMID: 25787135 DOI: 10.1128/cvi.00792-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 03/03/2015] [Indexed: 12/20/2022]
Abstract
The anthrax protective antigen (PA) is the central component of the three-part anthrax toxin, and it is the primary immunogenic component in the approved AVA anthrax vaccine and the "next-generation" recombinant PA (rPA) anthrax vaccines. Animal models have indicated that PA-specific antibodies (AB) are sufficient to protect against infection with Bacillus anthracis. In this study, we investigated the PA domain specificity, affinity, mechanisms of neutralization, and synergistic effects of PA-specific antibodies from a single donor following vaccination with the rPA vaccine. Antibody-secreting cells were isolated 7 days after the donor received a boost vaccination, and 34 fully human monoclonal antibodies (hMAb) were identified. Clones 8H6, 4A3, and 22F1 were able to neutralize lethal toxin (LeTx) both in vitro and in vivo. Clone 8H6 neutralized LeTx by preventing furin cleavage of PA in a dose-dependent manner. Clone 4A3 enhanced degradation of nicked PA, thereby interfering with PA oligomerization. The mechanism of 22F1 is still unclear. A fourth clone, 2A6, that was protective only in vitro was found to be neutralizing in vivo in combination with a toxin-enhancing antibody, 8A7, which binds to domain 3 of PA and PA oligomers. These results provide novel insights into the antibody response elicited by the rPA vaccine and may be useful for PA-based vaccine and immunotherapeutic cocktail design.
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Kaur M, Singh S, Bhatnagar R. Anthrax vaccines: present status and future prospects. Expert Rev Vaccines 2014; 12:955-70. [PMID: 23984963 DOI: 10.1586/14760584.2013.814860] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The management of anthrax remains a top priority among the biowarfare/bioterror agents. It was the Bacillus anthracis spore attack through the US mail system after the September 11, 2001, terrorist attacks in the USA that highlighted the potential of B. anthracis as a bioterrorism agent and the threat posed by its deliberate dissemination. These attacks invigorated the efforts toward understanding the anthrax pathogenesis and development of more comprehensive medical intervention strategies for its containment in case of both natural disease and manmade, accidental or deliberate infection of a non-suspecting population. Currently, efforts are directed toward the development of safe and efficacious vaccines as well as intervention tools for controlling the disease in the advanced fulminant stage when toxemia has already developed. This work presents an overview of the current understanding of anthrax pathogenesis and recent advances made, particularly after 2001, for the successful management of anthrax and outlines future perspectives.
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Affiliation(s)
- Manpreet Kaur
- Laboratory of Molecular Biology and Genetic Engineering, School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, Delhi, India
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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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Bouzianas DG. Potential biological targets ofBacillus anthracisin anti-infective approaches against the threat of bioterrorism. Expert Rev Anti Infect Ther 2014; 5:665-84. [PMID: 17678429 DOI: 10.1586/14787210.5.4.665] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The terrorist attacks of 2001 involving anthrax underscore the imperative that safe and effective medical countermeasures should be readily available. Vaccination appears to be the most effective form of mass protection against a biological attack, but the current vaccines have drawbacks that justify the enormous amount of effort currently being put into developing more effective vaccines and other treatment modalities. After providing a comprehensive overview of the organism Bacillus anthracis as a biological weapon and its pathogenicity, this review briefly summarizes the current knowledge vital to the management of anthrax disease. This knowledge has been acquired since 2001 as a result of the progress on anthrax research and focuses on the possible development of improved human anti-infective strategies targeting B. anthracis spore components, as well as strategies based on host-pathogen interactions.
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Affiliation(s)
- Dimitrios G Bouzianas
- Department of Medical Laboratories, Faculty of Health and Care Professions, University-level Technological Educational Institute of Thessaloniki, Greece.
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Williams JD, Khan AR, Cardinale SC, Butler MM, Bowlin TL, Peet NP. Small molecule inhibitors of anthrax lethal factor toxin. Bioorg Med Chem 2013; 22:419-34. [PMID: 24290062 DOI: 10.1016/j.bmc.2013.11.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Revised: 10/29/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
Abstract
This manuscript describes the preparation of new small molecule inhibitors of Bacillus anthracis lethal factor. Our starting point was the symmetrical, bis-quinolinyl compound 1 (NSC 12155). Optimization of one half of this molecule led to new LF inhibitors that were desymmetrized to afford more drug-like compounds.
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Affiliation(s)
- John D Williams
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Atiyya R Khan
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Steven C Cardinale
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Michelle M Butler
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Terry L Bowlin
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States
| | - Norton P Peet
- Microbiotix, Inc., Department of Medicinal Chemistry, One Innovation Drive, Worcester, MA 01605, United States; Microbiotix, Inc., Department of Molecular Biology, One Innovation Drive, Worcester, MA 01605, United States.
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18
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Affiliation(s)
| | - Sergey M. Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, U.S.A
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A three-dose intramuscular injection schedule of anthrax vaccine adsorbed generates sustained humoral and cellular immune responses to protective antigen and provides long-term protection against inhalation anthrax in rhesus macaques. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1730-45. [PMID: 22933399 DOI: 10.1128/cvi.00324-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 3-dose (0, 1, and 6 months) intramuscular (3-IM) priming series of a human dose (HuAVA) and dilutions of up to 1:10 of anthrax vaccine adsorbed (AVA) provided statistically significant levels of protection (60 to 100%) against inhalation anthrax for up to 4 years in rhesus macaques. Serum anti-protective antigen (anti-PA) IgG and lethal toxin neutralization activity (TNA) were detectable following a single injection of HuAVA or 1:5 AVA or following two injections of diluted vaccine (1:10, 1:20, or 1:40 AVA). Anti-PA and TNA were highly correlated (overall r(2) = 0.89 for log(10)-transformed data). Peak responses were seen at 6.5 months. In general, with the exception of animals receiving 1:40 AVA, serum anti-PA and TNA responses remained significantly above control levels at 28.5 months (the last time point measured for 1:20 AVA), and through 50.5 months for the HuAVA and 1:5 and 1:10 AVA groups (P < 0.05). PA-specific gamma interferon (IFN-γ) and interleukin-4 (IL-4) CD4(+) cell frequencies and T cell stimulation indices were sustained through 50.5 months (the last time point measured). PA-specific memory B cell frequencies were highly variable but, in general, were detectable in peripheral blood mononuclear cells (PBMC) by 2 months, were significantly above control levels by 7 months, and remained detectable in the HuAVA and 1:5 and 1:20 AVA groups through 42 months (the last time point measured). HuAVA and diluted AVA elicited a combined Th1/Th2 response and robust immunological priming, with sustained production of high-avidity PA-specific functional antibody, long-term immune cell competence, and immunological memory (30 months for 1:20 AVA and 52 months for 1:10 AVA). Vaccinated animals surviving inhalation anthrax developed high-magnitude anamnestic anti-PA IgG and TNA responses.
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Characterization of a therapeutic model of inhalational anthrax using an increase in body temperature in New Zealand white rabbits as a trigger for treatment. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1517-25. [PMID: 22837095 DOI: 10.1128/cvi.00292-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The development of an appropriate animal therapeutic model is essential to assess the potential efficacy of therapeutics for use in the event of a Bacillus anthracis exposure. We conducted a natural history study that showed New Zealand White rabbits exhibited a significant increase in body temperature (SIBT), changes in hematologic parameters, and increases in C-reactive protein and succumbed to disease with an average time to death of approximately 73 h following aerosol challenge with B. anthracis Ames spores. The SIBT was used as a trigger to treat with a fully human monoclonal antibody directed at protective antigen (PA). Ninety percent (9/10) of the treated rabbits survived the lethal inhalational challenge of B. anthracis. Further characterization investigated the protective window of opportunity for anti-PA antibody administration up to 12 h post-onset of SIBT. Eighty-three percent (5/6) of the rabbits treated at SIBT and 100% (6/6) of those treated at 6 h after SIBT survived challenge. Only 67% (4/6) of the rabbits treated at 12 h after SIBT survived. The increase in body temperature corresponded with both bacteremia and antigenemia (PA in the blood), indicating that SIBT is a suitable trigger to initiate treatment in a therapeutic model of inhalational anthrax.
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Artenstein AW, Opal SM. Novel approaches to the treatment of systemic anthrax. Clin Infect Dis 2012; 54:1148-61. [PMID: 22438345 DOI: 10.1093/cid/cis017] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Anthrax continues to generate concern as an agent of bioterrorism and as a natural cause of sporadic disease outbreaks. Despite the use of appropriate antimicrobial agents and advanced supportive care, the mortality associated with the systemic disease remains high. This is primarily due to the pathogenic exotoxins produced by Bacillus anthracis as well as other virulence factors of the organism. For this reason, new therapeutic strategies that target events in the pathogenesis of anthrax and may potentially augment antimicrobials are being investigated. These include anti-toxin approaches, such as passive immune-based therapies; non-antimicrobial drugs with activity against anthrax toxin components; and agents that inhibit binding, processing, or assembly of toxins. Adjunct therapies that target spore germination or downstream events in anthrax intoxication are also under investigation. In combination, these modalities may enhance the management of systemic anthrax.
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Affiliation(s)
- Andrew W Artenstein
- Center for Biodefense and Emerging Pathogens, Department of Medicine, Memorial Hospital of Rhode Island, Pawtucket, and The Warren Alpert Medical School of Brown University, Providence, RI 02860, USA
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Chow SK, Casadevall A. Monoclonal antibodies and toxins--a perspective on function and isotype. Toxins (Basel) 2012; 4:430-54. [PMID: 22822456 PMCID: PMC3398419 DOI: 10.3390/toxins4060430] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Revised: 06/06/2012] [Accepted: 06/07/2012] [Indexed: 11/16/2022] Open
Abstract
Antibody therapy remains the only effective treatment for toxin-mediated diseases. The development of hybridoma technology has allowed the isolation of monoclonal antibodies (mAbs) with high specificity and defined properties, and numerous mAbs have been purified and characterized for their protective efficacy against different toxins. This review summarizes the mAb studies for 6 toxins—Shiga toxin, pertussis toxin, anthrax toxin, ricin toxin, botulinum toxin, and Staphylococcal enterotoxin B (SEB)—and analyzes the prevalence of mAb functions and their isotypes. Here we show that most toxin-binding mAbs resulted from immunization are non-protective and that mAbs with potential therapeutic use are preferably characterized. Various common practices and caveats of protection studies are discussed, with the goal of providing insights for the design of future research on antibody-toxin interactions.
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Affiliation(s)
- Siu-Kei Chow
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA;
| | - Arturo Casadevall
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA;
- Division of Infectious Diseases of the Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave, Bronx, NY 10461, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-718-430-2811; Fax: +1-718-430-8711
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Smith K, Crowe SR, Garman L, Guthridge CJ, Muther JJ, McKee E, Zheng NY, Farris AD, Guthridge JM, Wilson PC, James JA. Human monoclonal antibodies generated following vaccination with AVA provide neutralization by blocking furin cleavage but not by preventing oligomerization. Vaccine 2012; 30:4276-83. [PMID: 22425791 DOI: 10.1016/j.vaccine.2012.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 02/09/2012] [Accepted: 03/01/2012] [Indexed: 12/28/2022]
Abstract
In order to identify the combination of antibody-mediated mechanisms of neutralization that result from vaccination with anthrax vaccine adsorbed (AVA), we isolated antibody secreting cells from a single donor seven days after booster vaccination with AVA and generated nine fully human monoclonal antibodies (hmAb) with high specificity for protective antigen (PA). Two of the antibodies were able to neutralize lethal toxin in vitro at low concentrations (IC(50): p6C01, 0.12 μg/ml and p6F01, 0.45 μg/ml). Passive transfer of either of these hmAbs to A/J mice prior to challenge with lethal toxin conferred 80-90% protection. We demonstrate that hmAb p6C01 is neutralizing by preventing furin cleavage of PA in a dose-dependent manner, but the mechanism of p6F01 is unclear. Three additional antibodies were found to bind to domain 3 of PA and prevent oligomerization, although they did not confer significant protection in vivo and showed a significant prozone-like effect in vitro. These fully human antibodies provide insight into the neutralizing response to AVA for future subunit vaccine and passive immunotherapeutic cocktail design.
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Affiliation(s)
- Kenneth Smith
- Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma City, OK 73104, USA
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Froude JW, Stiles B, Pelat T, Thullier P. Antibodies for biodefense. MAbs 2011; 3:517-27. [PMID: 22123065 PMCID: PMC3242838 DOI: 10.4161/mabs.3.6.17621] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 08/03/2011] [Indexed: 12/11/2022] Open
Abstract
Potential bioweapons are biological agents (bacteria, viruses, and toxins) at risk of intentional dissemination. Biodefense, defined as development of therapeutics and vaccines against these agents, has seen an increase, particularly in the US following the 2001 anthrax attack. This review focuses on recombinant antibodies and polyclonal antibodies for biodefense that have been accepted for clinical use. These antibodies aim to protect against primary potential bioweapons, or category A agents as defined by the Centers for Disease Control and Prevention (Bacillus anthracis, Yersinia pestis, Francisella tularensis, botulinum neurotoxins, smallpox virus, and certain others causing viral hemorrhagic fevers) and certain category B agents. Potential for prophylactic use is presented, as well as frequent use of oligoclonal antibodies or synergistic effect with other molecules. Capacities and limitations of antibodies for use in biodefense are discussed, and are generally applicable to the field of infectious diseases.
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Affiliation(s)
- Jeffrey W Froude
- US Army Medical Research and Material Command; Fort Detrick, MD USA
- Unité de biotechnologie des anticorps et des toxines; Département de Microbiologie; Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); La Tronche Cedex, France
| | - Bradley Stiles
- US Army Medical Research Institute of Infectious Diseases; Fort Detrick, MD USA
| | - Thibaut Pelat
- Unité de biotechnologie des anticorps et des toxines; Département de Microbiologie; Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); La Tronche Cedex, France
| | - Philippe Thullier
- Unité de biotechnologie des anticorps et des toxines; Département de Microbiologie; Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); La Tronche Cedex, France
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25
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Monoclonal antibody therapies against anthrax. Toxins (Basel) 2011; 3:1004-19. [PMID: 22069754 PMCID: PMC3202866 DOI: 10.3390/toxins3081004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/06/2011] [Accepted: 08/10/2011] [Indexed: 12/15/2022] Open
Abstract
Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. It not only causes natural infection in humans but also poses a great threat as an emerging bioterror agent. The lethality of anthrax is primarily attributed to the two major virulence factors: toxins and capsule. An extensive effort has been made to generate therapeutically useful monoclonal antibodies to each of the virulence components: protective antigen (PA), lethal factor (LF) and edema factor (EF), and the capsule of B. anthracis. This review summarizes the current status of anti-anthrax mAb development and argues for the potential therapeutic advantage of a cocktail of mAbs that recognize different epitopes or different virulence factors.
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Sawada R, Sun SM, Wu X, Hong F, Ragupathi G, Livingston PO, Scholz WW. Human monoclonal antibodies to sialyl-Lewis (CA19.9) with potent CDC, ADCC, and antitumor activity. Clin Cancer Res 2011; 17:1024-32. [PMID: 21343375 DOI: 10.1158/1078-0432.ccr-10-2640] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE The carbohydrate antigen sialyl-Lewis(a) (sLe(a)), also known as CA19.9, is widely expressed on epithelial tumors of the gastrointestinal tract and breast and on small-cell lung cancers. Since overexpression of sLe(a) appears to be a key event in invasion and metastasis of many tumors and results in susceptibility to antibody-mediated lysis, sLe(a) is an attractive molecular target for tumor therapy. EXPERIMENTAL DESIGN We generated and characterized fully human monoclonal antibodies (mAb) from blood lymphocytes from individuals immunized with a sLe(a)-KLH vaccine. RESULTS Several mAbs were selected based on ELISA and FACS including two mAbs with high affinity for sLe(a) (5B1 and 7E3, binding affinities 0.14 and 0.04 nmol/L, respectively) and further characterized. Both antibodies were specific for Neu5Acα2-3Galβ1-3(Fucα1-4)GlcNAcβ as determined by glycan array analysis. Complement-dependent cytotoxicity against DMS-79 cells was higher (EC(50) 0.1 μg/mL vs. 1.7 μg/mL) for r7E3 (IgM) than for r5B1 (IgG1). In addition, r5B1 antibodies showed high level of antibody-dependent cell-mediated cytotoxicity activity on DMS-79 cells with human NK cells or peripheral blood mononuclear cells. To evaluate in vivo efficacy, the antibodies were tested in a xenograft model with Colo205 tumor cells engrafted into SCID (severe combined immunodeficient mice) mice. Treatment during the first 21 days with four doses of r5B1 (100 μg per dose) doubled the median survival time to 207 days, and three of five animals survived with six doses. CONCLUSION On the basis of the potential of sLe(a) as a target for immune attack and their affinity, specificity, and effector functions, 5B1and 7E3 may have clinical utility.
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Wycoff KL, Belle A, Deppe D, Schaefer L, Maclean JM, Haase S, Trilling AK, Liu S, Leppla SH, Geren IN, Pawlik J, Peterson JW. Recombinant anthrax toxin receptor-Fc fusion proteins produced in plants protect rabbits against inhalational anthrax. Antimicrob Agents Chemother 2011; 55:132-9. [PMID: 20956592 PMCID: PMC3019684 DOI: 10.1128/aac.00592-10] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/03/2010] [Accepted: 10/07/2010] [Indexed: 11/20/2022] Open
Abstract
Inhalational anthrax, a zoonotic disease caused by the inhalation of Bacillus anthracis spores, has a ∼50% fatality rate even when treated with antibiotics. Pathogenesis is dependent on the activity of two toxic noncovalent complexes: edema toxin (EdTx) and lethal toxin (LeTx). Protective antigen (PA), an essential component of both complexes, binds with high affinity to the major receptor mediating the lethality of anthrax toxin in vivo, capillary morphogenesis protein 2 (CMG2). Certain antibodies against PA have been shown to protect against anthrax in vivo. As an alternative to anti-PA antibodies, we produced a fusion of the extracellular domain of human CMG2 and human IgG Fc, using both transient and stable tobacco plant expression systems. Optimized expression led to the CMG2-Fc fusion protein being produced at high levels: 730 mg/kg fresh leaf weight in Nicotiana benthamiana and 65 mg/kg in N. tabacum. CMG2-Fc, purified from tobacco plants, fully protected rabbits against a lethal challenge with B. anthracis spores at a dose of 2 mg/kg body weight administered at the time of challenge. Treatment with CMG2-Fc did not interfere with the development of the animals' own immunity to anthrax, as treated animals that survived an initial challenge also survived a rechallenge 30 days later. The glycosylation of the Fc (or lack thereof) had no significant effect on the protective potency of CMG2-Fc in rabbits or on its serum half-life, which was about 5 days. Significantly, CMG2-Fc effectively neutralized, in vitro, LeTx-containing mutant forms of PA that were not neutralized by anti-PA monoclonal antibodies.
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Passive vaccination with a human monoclonal antibody: generation of antibodies and studies for efficacy in Bacillus anthracis infections. Immunobiology 2010; 216:847-53. [PMID: 21397977 DOI: 10.1016/j.imbio.2010.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Accepted: 12/04/2010] [Indexed: 11/21/2022]
Abstract
A major difficulty in creating human monoclonal antibodies is the lack of a suitable myeloma cell line to be used for fusion experiments. In order to create fully human monoclonal antibodies for passive immunization, the human mouse heteromyeloma cell line CB-F7 was evaluated. Using this cell line, we generated human monoclonal antibodies against Bacillus anthracis toxin components. Antibodies against protective antigen (PA) and against lethal factor (LF) were obtained using peripheral blood lymphocytes (PBLs) from persons vaccinated with the UK anthrax vaccine. PBL were fused with the cell line CB-F7. We obtained several clones producing PA specific Ig and one clone (hLF1-SAN) producing a monoclonal antibody (hLF1) directed against LF. The LF binding antibody was able to neutralize Anthrax toxin activity in an in vitro neutralization assay, and preliminary in vivo studies in mice also indicated a trend towards protection. We mapped the epitope of the antibody binding to LF by dot blot analysis and ELIFA using 80 synthetic LF peptides of 20 amino acid lengths with an overlapping range of 10 amino acids. Our results suggest the binding of the monoclonal antibody to the peptide regions 121-150 or 451-470 of LF. The Fab-fragment of the antibody hLF1 was cloned in Escherichia coli and could be useful as part of a fully human monoclonal antibody for the treatment of Anthrax infections. In general, our studies show the applicability of the CB-F7 line to create fully human monoclonal antibodies for vaccination.
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Díaz-Moscoso A, Méndez-Ardoy A, Ortega-Caballero F, Benito JM, Ortiz Mellet C, Defaye J, Robinson TM, Yohannes A, Karginov VA, García Fernández JM. Symmetry Complementarity-Guided Design of Anthrax Toxin Inhibitors Based on β-Cyclodextrin: Synthesis and Relative Activities of Face-Selective Functionalized Polycationic Clusters. ChemMedChem 2010; 6:181-92. [DOI: 10.1002/cmdc.201000419] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Thullier P, Pelat T, Paucod JC, Vidal D. [Recombinant antibodies for medical protection against bioterrorism agents: the example of anthrax]. Biol Aujourdhui 2010; 204:81-6. [PMID: 20950579 DOI: 10.1051/jbio/2009048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2009] [Indexed: 11/14/2022]
Abstract
Recombinant antibodies are a highly successful class of therapeutic molecules, they are well adapted for use against bio-weapons (BW) as they act immediately, are often synergistic with other therapeutic molecules, have a long half-life and are well tolerated. Anthrax is regarded at high risk of being used as BW, and its pathogenic properties depend on toxins, which might be neutralized by antibodies. These toxins are made of three different types of sub-units (PA, LF, EF). Several anti-PA have been developed, including an original approach by our team. We have developed an anti-LF, as recommended by experts. Our anti-PA antibody, and to a lesser extend our anti-LF antibody, will be presented here.
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Affiliation(s)
- Philippe Thullier
- Institut de Recherche Biomédicale des Armées, Centre de Recherche du Service de Santé des Armées (CRSSA), 24 avenue des Maquis du Grésivaudan, La Tronche, France.
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A chimeric protein that functions as both an anthrax dual-target antitoxin and a trivalent vaccine. Antimicrob Agents Chemother 2010; 54:4750-7. [PMID: 20713663 DOI: 10.1128/aac.00640-10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Effective measures for the prophylaxis and treatment of anthrax are still required for counteracting the threat posed by inhalation anthrax. In this study, we first demonstrated that the chimeric protein LFn-PA, created by fusing the protective antigen (PA)-binding domain of lethal factor (LFn) to PA, retained the functions of the respective molecules. On the basis of this observation, we attempted to develop an antitoxin that targets the binding of lethal factor (LF) and/or edema factor (EF) to PA and the transportation of LF/EF. Therefore, we replaced PA in LFn-PA with a dominant-negative inhibitory PA (DPA), i.e., PA(F427D). In in vitro models of anthrax intoxication, the LFn-DPA chimera showed 3-fold and 2-fold higher potencies than DPA in protecting sensitive cells against anthrax lethal toxin (LeTx) and edema toxin (EdTx), respectively. In animal models, LFn-DPA exhibited strong potency in rescuing mice from lethal challenge with LeTx. We also evaluated the immunogenicity and immunoprotective efficacy of LFn-DPA as an anthrax vaccine candidate. In comparison with recombinant PA, LFn-DPA induced significantly higher levels of the anti-PA immune response. Moreover, LFn-DPA elicited an anti-LF antibody response that could cross-react with EF. Mice immunized with LFn-DPA tolerated a LeTx challenge that was 5 times its 50% lethal dose. Thus, LFn-DPA represents a highly effective trivalent vaccine candidate for both preexposure and postexposure vaccination. Overall, we have developed a novel and dually functional reagent for the prophylaxis and treatment of anthrax.
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Crowe SR, Ash LL, Engler RJM, Ballard JD, Harley JB, Farris AD, James JA. Select human anthrax protective antigen epitope-specific antibodies provide protection from lethal toxin challenge. J Infect Dis 2010; 202:251-60. [PMID: 20533877 DOI: 10.1086/653495] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Bacillus anthracis remains a serious bioterrorism concern, and the currently licensed vaccine remains an incomplete solution for population protection from inhalation anthrax and has been associated with concerns regarding efficacy and safety. Thus, understanding how to generate long-lasting protective immunity with reduced immunizations or provide protection through postexposure immunotherapeutics are long-sought goals. Through evaluation of a large military cohort, we characterized the levels of antibodies against protective antigen and found that over half of anthrax vaccinees had low serum levels of in vitro toxin neutralization capacity. Using solid-phase epitope mapping and confirmatory assays, we identified several neutralization-associated humoral epitopes and demonstrated that select antipeptide responses mediated protection in vitro. Finally, passively transferred antibodies specific for select epitopes provided protection in an in vivo lethal toxin mouse model. Identification of these antigenic regions has important implications for vaccine design and the development of directed immunotherapeutics.
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Affiliation(s)
- Sherry R Crowe
- Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
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Abstract
Human monoclonal antibodies (mAbs) have become drugs of choice for the management of an increasing number of human diseases. Human antibody repertoires provide a rich source for human mAbs. Here we review the characteristics of natural and non-natural human antibody repertoires and their mining with non-combinatorial and combinatorial strategies. In particular, we discuss the selection of human mAbs from naïve, immune, transgenic, and synthetic human antibody repertoires using methods based on hybridoma technology, clonal expansion of peripheral B cells, single-cell PCR, phage display, yeast display, and mammalian cell display. Our reliance on different strategies is shifting as we gain experience and refine methods to the efficient generation of human mAbs with superior pharmacokinetic and pharmacodynamic properties.
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Affiliation(s)
| | - Christoph Rader
- 2Experimental Transplantation and Immunology Branch, Center for Cancer Research, National Cancer Institute
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34
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Abstract
Human monoclonal antibodies (mAbs) have become drugs of choice for the management of an increasing number of human diseases. Human antibody repertoires provide a rich source for human mAbs. Here we review the characteristics of natural and non-natural human antibody repertoires and their mining with non-combinatorial and combinatorial strategies. In particular, we discuss the selection of human mAbs from naïve, immune, transgenic, and synthetic human antibody repertoires using methods based on hybridoma technology, clonal expansion of peripheral B cells, single-cell PCR, phage display, yeast display, and mammalian cell display. Our reliance on different strategies is shifting as we gain experience and refine methods to the efficient generation of human mAbs with superior pharmacokinetic and pharmacodynamic properties.
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Affiliation(s)
| | - Christoph Rader
- 2Experimental Transplantation and Immunology Branch, Center for Cancer Research, National Cancer Institute
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Peterson JW, Moen ST, Healy D, Pawlik JE, Taormina J, Hardcastle J, Thomas JM, Lawrence WS, Ponce C, Chatuev BM, Gnade BT, Foltz SM, Agar SL, Sha J, Klimpel GR, Kirtley ML, Eaves-Pyles T, Chopra AK. Protection Afforded by Fluoroquinolones in Animal Models of Respiratory Infections with Bacillus anthracis, Yersinia pestis, and Francisella tularensis. Open Microbiol J 2010; 4:34-46. [PMID: 21127743 PMCID: PMC2995158 DOI: 10.2174/1874285801004010034] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 04/19/2010] [Accepted: 04/23/2010] [Indexed: 11/28/2022] Open
Abstract
Successful treatment of inhalation anthrax, pneumonic plague and tularemia can be achieved with fluoroquinolone antibiotics, such as ciprofloxacin and levofloxacin, and initiation of treatment is most effective when administered as soon as possible following exposure. Bacillus anthracis Ames, Yersinia pestis CO92, and Francisella tularensis SCHU S4 have equivalent susceptibility in vitro to ciprofloxacin and levofloxacin (minimal inhibitory concentration is 0.03 μg/ml); however, limited information is available regarding in vivo susceptibility of these infectious agents to the fluoroquinolone antibiotics in small animal models. Mice, guinea pig, and rabbit models have been developed to evaluate the protective efficacy of antibiotic therapy against these life-threatening infections. Our results indicated that doses of ciprofloxacin and levofloxacin required to protect mice against inhalation anthrax were approximately 18-fold higher than the doses of levofloxacin required to protect against pneumonic plague and tularemia. Further, the critical period following aerosol exposure of mice to either B. anthracis spores or Y. pestis was 24 h, while mice challenged with F. tularensis could be effectively protected when treatment was delayed for as long as 72 h postchallenge. In addition, it was apparent that prolonged antibiotic treatment was important in the effective treatment of inhalation anthrax in mice, but short-term treatment of mice with pneumonic plague or tularemia infections were usually successful. These results provide effective antibiotic dosages in mice, guinea pigs, and rabbits and lay the foundation for the development and evaluation of combinational treatment modalities.
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Affiliation(s)
- Johnny W Peterson
- Department of Microbiology and Immunology, Galveston National Laboratory, University of Texas Medical Branch, 301 University Blvd. Galveston, Texas 77555-0610
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Andrianov V, Brodzik R, Spitsin S, Bandurska K, McManus H, Koprowski H, Golovkin M. Production of recombinant anthrax toxin receptor (ATR/CMG2) fused with human Fc in planta. Protein Expr Purif 2010; 70:158-62. [PMID: 19796689 DOI: 10.1016/j.pep.2009.09.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Revised: 09/21/2009] [Accepted: 09/23/2009] [Indexed: 11/23/2022]
Abstract
Mass vaccination against anthrax with existing vaccines is costly and unsafe due to potential side effects. For post-infection treatment, passive immunotherapy measures are currently available, most based on anthrax protective antigen (PA)-specific therapeutic antibodies. Efficient against wild-type strains, these treatment(s) might fail to protect against infections caused by genetically engineered Bacillus anthracis strains. A recent discovery revealed that the von Willebrand factor A (VWA) domain of human capillary morphogenesis protein 2 (CMG2) is an exceptionally effective anthrax toxin receptor (ATR) proficient in helping to resolve this issue. Here we describe in planta production of chimeric recombinant protein (immunoadhesin) comprised of functional ATR domain fused with the human immunoglobulin Fc fragment (pATR-Fc). The fusion design allowed us to obtain pATR-Fc in plant green tissues in a soluble form making it fairly easy to purify by Protein-A chromatography. Standardized pATR-Fc preparations (purity>90%) were shown to efficiently bind anthrax PA as demonstrated by ELISA and Western blot analysis. Recombinant pATR-Fc was also shown to protect J774A1 macrophage cells against the anthrax toxin. This study confirmed that plant-derived pATR-Fc antibody-like protein is a prospective candidate for anthrax immunotherapy.
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Affiliation(s)
- V Andrianov
- Biotechnology Foundation Laboratories at Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
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37
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Tran M, Zhou B, Pettersson PL, Gonzalez MJ, Mayfield SP. Synthesis and assembly of a full-length human monoclonal antibody in algal chloroplasts. Biotechnol Bioeng 2009; 104:663-73. [PMID: 19562731 DOI: 10.1002/bit.22446] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Monoclonal antibodies can be effective therapeutics against a variety of human diseases, but currently marketed antibody-based drugs are very expensive compared to other therapeutic options. Here, we show that the eukaryotic green algae Chlamydomonas reinhardtii is capable of synthesizing and assembling a full-length IgG1 human monoclonal antibody (mAb) in transgenic chloroplasts. This antibody, 83K7C, is derived from a human IgG1 directed against anthrax protective antigen 83 (PA83), and has been shown to block the effects of anthrax toxin in animal models. Here we show that 83K7C heavy and light chain proteins expressed in the chloroplast accumulate as soluble proteins that assemble into complexes containing two heavy and two light chain proteins. The algal-expressed 83K7C binds PA83 in vitro with similar affinity to the mammalian-expressed 83K7C antibody. In addition, a second human IgG1 and a mouse IgG1 were also expressed and shown to properly assemble in algal chloroplast. These results show that chloroplasts have the ability to fold and assemble full-length human mAbs, and suggest the potential of algae as a platform for the cost effective production of complex human therapeutic proteins.
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Affiliation(s)
- Miller Tran
- Department of Cell Biology, The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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Cybulski RJ, Sanz P, O'Brien AD. Anthrax vaccination strategies. Mol Aspects Med 2009; 30:490-502. [PMID: 19729034 DOI: 10.1016/j.mam.2009.08.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Accepted: 08/24/2009] [Indexed: 01/10/2023]
Abstract
The biological attack conducted through the US postal system in 2001 broadened the threat posed by anthrax from one pertinent mainly to soldiers on the battlefield to one understood to exist throughout our society. The expansion of the threatened population placed greater emphasis on the reexamination of how we vaccinate against Bacillus anthracis. The currently-licensed Anthrax Vaccine, Adsorbed (AVA) and Anthrax Vaccine, Precipitated (AVP) are capable of generating a protective immune response but are hampered by shortcomings that make their widespread use undesirable or infeasible. Efforts to gain US Food and Drug Administration (FDA) approval for licensure of a second generation recombinant protective antigen (rPA)-based anthrax vaccine are ongoing. However, this vaccine's reliance on the generation of a humoral immune response against a single virulence factor has led a number of scientists to conclude that the vaccine is likely not the final solution to optimal anthrax vaccine design. Other vaccine approaches, which seek a more comprehensive immune response targeted at multiple components of the B. anthracis organism, are under active investigation. This review seeks to summarize work that has been done to build on the current PA-based vaccine methodology and to evaluate the search for future anthrax prophylaxis strategies.
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Affiliation(s)
- Robert J Cybulski
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814-4799, United States
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Chen Z, Moayeri M, Zhao H, Crown D, Leppla SH, Purcell RH. Potent neutralization of anthrax edema toxin by a humanized monoclonal antibody that competes with calmodulin for edema factor binding. Proc Natl Acad Sci U S A 2009; 106:13487-92. [PMID: 19651602 PMCID: PMC2726367 DOI: 10.1073/pnas.0906581106] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2009] [Indexed: 11/18/2022] Open
Abstract
This study describes the isolation and characterization of a neutralizing monoclonal antibody (mAb) against anthrax edema factor, EF13D. EF13D neutralized edema toxin (ET)-mediated cyclic AMP (cAMP) responses in cells and protected mice from both ET-induced footpad edema and systemic ET-mediated lethality. The antibody epitope was mapped to domain IV of EF. The mAb was able to compete with calmodulin (CaM) for EF binding and displaced CaM from EF-CaM complexes. EF-mAb binding affinity (0.05-0.12 nM) was 50- to 130-fold higher than that reported for EF-CaM. This anti-EF neutralizing mAb could potentially be used alone or with an anti-PA mAb in the emergency prophylaxis and treatment of anthrax infection.
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Affiliation(s)
| | - Mahtab Moayeri
- Laboratory of Bacterial Diseases, National Institute of Allergy and Infectious Diseases, and
| | - Huaying Zhao
- National Institute for Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892
| | - Devorah Crown
- Laboratory of Bacterial Diseases, National Institute of Allergy and Infectious Diseases, and
| | - Stephen H. Leppla
- Laboratory of Bacterial Diseases, National Institute of Allergy and Infectious Diseases, and
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Rosenfeld R, Marcus H, Ben-Arie E, Lachmi BE, Mechaly A, Reuveny S, Gat O, Mazor O, Ordentlich A. Isolation and chimerization of a highly neutralizing antibody conferring passive protection against lethal Bacillus anthracis infection. PLoS One 2009; 4:e6351. [PMID: 19629185 PMCID: PMC2710523 DOI: 10.1371/journal.pone.0006351] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2009] [Accepted: 06/22/2009] [Indexed: 11/18/2022] Open
Abstract
Several studies have demonstrated that the passive transfer of protective antigen (PA)-neutralizing antibodies can protect animals against Bacillus anthracis infection. The standard protocol for the isolation of PA-neutralizing monoclonal antibodies is based upon a primary selection of the highest PA-binders by ELISA, and usually yields only few candidates antibodies. We demonstrated that by applying a PA-neutralization functionality-based screen as the primary criterion for positive clones, it was possible to isolate more than 100 PA-neutralizing antibodies, some of which exhibited no measurable anti-PA titers in ELISA. Among the large panel of neutralizing antibodies identified, mAb 29 demonstrated the most potent activity, and was therefore chimerized. The variable region genes of the mAb 29 were fused to human constant region genes, to form the chimeric 29 antibody (cAb 29). Guinea pigs were fully protected against infection by 40LD(50)B. anthracis spores following two separate administrations with 10 mg/kg of cAb 29: the first administration was given before the challenge, and a second dose was administered on day 4 following exposure. Moreover, animals that survived the challenge and developed endogenous PA-neutralizing antibodies with neutralizing titers above 100 were fully protected against repeat challenges with 40LD(50) of B. anthracis spores. The data presented here emphasize the importance of toxin neutralization-based screens for the efficient isolation of protective antibodies that were probably overlooked in the standard screening protocol. The protective activity of the chimeric cAb 29 demonstrated in this study suggest that it may serve as an effective immunotherapeutic agent against anthrax.
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Affiliation(s)
- Ronit Rosenfeld
- Departments of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Hadar Marcus
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Einat Ben-Arie
- Departments of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Bat-El Lachmi
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Adva Mechaly
- Department of Infectious Diseases, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Shaul Reuveny
- Department of Biotechnology, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Orit Gat
- Departments of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Ohad Mazor
- Departments of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
| | - Arie Ordentlich
- Departments of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness-Ziona, Israel
- * E-mail:
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Novel chimpanzee/human monoclonal antibodies that neutralize anthrax lethal factor, and evidence for possible synergy with anti-protective antigen antibody. Infect Immun 2009; 77:3902-8. [PMID: 19528217 DOI: 10.1128/iai.00200-09] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three chimpanzee Fabs reactive with lethal factor (LF) of anthrax toxin were isolated and converted into complete monoclonal antibodies (MAbs) with human gamma1 heavy-chain constant regions. In a macrophage toxicity assay, two of the MAbs, LF10E and LF11H, neutralized lethal toxin (LT), a complex of LF and anthrax protective antigen (PA). LF10E has the highest reported affinity for a neutralizing MAb against LF (dissociation constant of 0.69 nM). This antibody also efficiently neutralized LT in vitro, with a 50% effective concentration (EC(50)) of 0.1 nM, and provided 100% protection of rats against toxin challenge with a 0.5 submolar ratio relative to LT. LF11H, on the other hand, had a slightly lower binding affinity to LF (dissociation constant of 7.4 nM) and poor neutralization of LT in vitro (EC(50) of 400 nM) and offered complete protection in vivo only at an equimolar or higher ratio to toxin. Despite this, LF11H, but not LF10E, provided robust synergistic protection when combined with MAb W1, which neutralizes PA. Epitope mapping and binding assays indicated that both LF10E and LF11H recognize domain I of LF (amino acids 1 to 254). Although domain I is responsible for binding to PA, neither MAb prevented LF from binding to activated PA. Although two unique MAbs could protect against anthrax when used alone, even more efficient and broader protection should be gained by combining them with anti-PA MAbs.
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Schneemann A, Manchester M. Anti-toxin antibodies in prophylaxis and treatment of inhalation anthrax. Future Microbiol 2009; 4:35-43. [PMID: 19207098 DOI: 10.2217/17460913.4.1.35] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The CDC recommend 60 days of oral antibiotics combined with a three-dose series of the anthrax vaccine for prophylaxis after potential exposure to aerosolized Bacillus anthracis spores. The anthrax vaccine is currently not licensed for anthrax postexposure prophylaxis and has to be made available under an Investigational New Drug protocol. Postexposure prophylaxis based on antibiotics can be problematic in cases where the use of antibiotics is contraindicated. Furthermore, there is a concern that an exposure could involve antibiotic-resistant strains of B. anthracis. Availability of alternate treatment modalities that are effective in prophylaxis of inhalation anthrax is therefore highly desirable. A major research focus toward this end has been on passive immunization using polyclonal and monoclonal antibodies against B. anthracis toxin components. Since 2001, significant progress has been made in isolation and commercial development of monoclonal and polyclonal antibodies that function as potent neutralizers of anthrax lethal toxin in both a prophylactic and therapeutic setting. Several new products have completed Phase I clinical trials and are slated for addition to the National Strategic Stockpile. These rapid advances were possible because of major funding made available by the US government through programs such as Bioshield and the Biomedical Advanced Research and Development Authority. Continued government funding is critical to support the development of a robust biodefense industry.
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Affiliation(s)
- Anette Schneemann
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
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Vuyisich M, Gnanakaran S, Lovchik JA, Lyons CR, Gupta G. A dual-purpose protein ligand for effective therapy and sensitive diagnosis of anthrax. Protein J 2009; 27:292-302. [PMID: 18649128 DOI: 10.1007/s10930-008-9137-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article reports the design of a bivalent protein ligand with dual use in therapy and diagnosis of anthrax caused by Bacillus anthracis. The ligand specifically binds to PA and thereby blocks the intracellular delivery of LF and EF toxins that, respectively, cause cell lysis and edema. The ligand is a chimeric scaffold with two PA-binding domains (called VWA) linked to an IgG-Fc frame. Molecular modeling and binding measurements reveal that the VWA-Fc dimer binds to PA with high affinity (K(D)=0.2 nM). An in vitro bio-luminescence assay shows that VWA-Fc (at nanomolar concentration) protects mouse macrophages from lysis by PA/LF. In vivo studies demonstrate that VWA-Fc at low doses (approximately 50 microg/animal) are able to rescue animals from lethal doses of PA/LF and B. anthracis spores. Finally, VWA-Fc is utilized as the capture molecule in the sensitive (down to 30 picomolar) detection of PA using surface plasmon resonance.
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Affiliation(s)
- Momchilo Vuyisich
- Biosciences Division, Group B-7, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
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44
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Crystal structure of the engineered neutralizing antibody M18 complexed to domain 4 of the anthrax protective antigen. J Mol Biol 2009; 387:680-93. [PMID: 19361425 DOI: 10.1016/j.jmb.2009.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2008] [Revised: 02/03/2009] [Accepted: 02/03/2009] [Indexed: 11/24/2022]
Abstract
The virulence of Bacillus anthracis is critically dependent on the cytotoxic components of the anthrax toxin, lethal factor (LF) and edema factor (EF). LF and EF gain entry into host cells through interactions with the protective antigen (PA), which binds to host cellular receptors such as CMG2. Antibodies that neutralize PA have been shown to confer protection in animal models and are undergoing intense clinical development. A murine monoclonal antibody, 14B7, has been reported to interact with domain 4 of PA (PAD4) and block its binding to CMG2. More recently, the 14B7 antibody was used as the platform for the selection of very high affinity, single-chain antibodies that have tremendous potential as a combination anthrax prophylactic and treatment. Here, we report the high-resolution X-ray structures of three high-affinity, single-chain antibodies in the 14B7 family; 14B7 and two high-affinity variants 1H and M18. In addition, we present the first neutralizing antibody-PA structure, M18 in complex with PAD4 at 3.8 A resolution. These structures provide insights into the mechanism of neutralization, and the effect of various mutations on antibody affinity, and enable a comparison between the binding of the M18 antibody and CMG2 with PAD4.
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Dadachova E, Rivera J, Revskaya E, Nakouzi A, Cahill SM, Blumenstein M, Xiao H, Rykunov D, Casadevall A. In vitro evaluation, biodistribution and scintigraphic imaging in mice of radiolabeled anthrax toxins. Nucl Med Biol 2008; 35:755-61. [PMID: 18848660 DOI: 10.1016/j.nucmedbio.2008.07.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Revised: 07/05/2008] [Accepted: 07/10/2008] [Indexed: 10/21/2022]
Abstract
INTRODUCTION There is a lot of interest towards creating therapies and vaccines for Bacillus anthracis, a bacterium which causes anthrax in humans and which spores can be made into potent biological weapons. Systemic injection of lethal factor (LF), edema factor (EF) and protective antigen (PA) in mice produces toxicity, and this protocol is commonly used to investigate the efficacy of specific antibodies in passive protection and vaccine studies. Availability of toxins labeled with imageable radioisotopes would allow to demonstrate their tissue distribution after intravenous injection at toxin concentration that are below pharmacologically significant to avoid masking by toxic effects. METHODS LF, EF and PA were radiolabeled with (188)Re and (99m)Tc, and their performance in vitro was evaluated by macrophages and Chinese hamster ovary cells toxicity assays and by binding to macrophages. Scintigraphic imaging and biodistribution of intravenously (IV) injected (99m)Tc-and (123)I-labeled toxins was performed in BALB/c mice. RESULTS Radiolabeled toxins preserved their biological activity. Scatchard-type analysis of the binding of radiolabeled PA to the J774.16 macrophage-like cells revealed 6.6 x 10(4) binding sites per cell with a dissociation constant of 6.7 nM. Comparative scintigraphic imaging of mice injected intravenously with either (99m)Tc-or (123)I-labeled PA, EF and LF toxins demonstrated similar biodistribution patterns with early localization of radioactivity in the liver, spleen, intestines and excretion through kidneys. The finding of renal excretion shortly after IV injection strongly suggests that toxins are rapidly degraded which could contribute to the variability of mouse toxigenic assays. Biodistribution studies confirmed that all three toxins concentrated in the liver and the presence of high levels of radioactivity again implied rapid degradation in vivo. CONCLUSIONS The availability of (188)Re and (99m)Tc-labeled PA, LF and EF toxins allowed us to confirm the number of PA binding sites per cell, to provide an estimate of the dissociation constant of PA for its receptor and to demonstrate tissue distribution of toxins in mice after intravenous injection.
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Affiliation(s)
- Ekaterina Dadachova
- Department of Nuclear Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Lü J, He R, Dong M, Zhang L, Wang X. Immunological dynamics in response to two anthrax vaccines in mice. ACTA ACUST UNITED AC 2008; 51:872-8. [PMID: 18815750 DOI: 10.1007/s11427-008-0119-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 06/02/2008] [Indexed: 11/28/2022]
Abstract
In order to understand the variation of humoral and cellular immune responses to A16R live spore and AVA vaccine and to identify efficient immunological parameters for the early evaluation of post immunization in mice, we dynamically monitored the antibody production and cellular responses after the vaccination of Balb/C mice with the anthrax vaccines. The results show that both anti-AVA and anti-Spore antibodies were detectable in the A16R live spore vaccinated group while high titers of anti-AVA antibodies but not anti-Spore antibodies existed in the AVA-immunized group. IgG1 and IgG2 were the major subtypes of IgG in both of the two groups. However, the IgG2a level was significantly higher in the A16R group than in the AVA group. At the cellular level, responses of antigen-specific TH2, TH1 and plasma cells were detected. The peripheral T(H)2 responses could be seen on day 5 after vaccination, and remained at a high level throughout the experiment (from day 5 post primary immunization to day 60 post the tertiary immunization); the T(H)1 responses to A16R vaccine appeared on day 5, while the responses to AVA could only be detected by day 7 after the secondary immunization; a low level of T(H)1 responses could be observed at the end of the experiment. Antigen-specific plasma cells could be found in the peripheral blood of both the immunized groups, however, the responses in the A16R group appeared earlier, lasted longer, and shown an ascending tendency until the end of the experiment when the plasma cell responses in the AVA group were reduced to a very low level. The results suggest that the multiple antigen containing A16R live spore vaccine induces better immune responses than AVA. Combined with serum antibody titers, T(H)2, T(H)1 and plasma cell responses could be used as immunological parameters for the evaluation of vaccine efficacy. These findings may afford new insight into the early evaluation of vaccination as well as being a powerful strategy for vaccine development.
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Affiliation(s)
- Jin Lü
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
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Improvement of an Antibody Neutralizing the Anthrax Toxin by Simultaneous Mutagenesis of Its Six Hypervariable Loops. J Mol Biol 2008; 378:1094-103. [DOI: 10.1016/j.jmb.2008.03.045] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2007] [Revised: 03/17/2008] [Accepted: 03/21/2008] [Indexed: 11/22/2022]
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De BP, Hackett NR, Crystal RG, Boyer JL. Rapid/Sustained Anti-anthrax Passive Immunity Mediated by Co-administration of Ad/AAV. Mol Ther 2008; 16:203-9. [DOI: 10.1038/sj.mt.6300344] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Zhou B, Carney C, Janda KD. Selection and characterization of human antibodies neutralizing Bacillus anthracis toxin. Bioorg Med Chem 2007; 16:1903-13. [PMID: 18023190 DOI: 10.1016/j.bmc.2007.11.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 10/05/2007] [Accepted: 11/01/2007] [Indexed: 11/30/2022]
Abstract
A less than adequate therapeutic plan for the treatment of anthrax in the 2001 bioterrorism attacks has highlighted the importance of developing alternative or complementary therapeutic approaches for biothreat agents. In these regards passive immunization possesses several important advantages over active vaccination and the use of antibiotics, as it can provide immediate protection against Bacillus anthracis. Herein, we report the selection and characterization of several human monoclonal neutralizing antibodies against the toxin of B. anthracis from a phage displayed human scFv library. In total 15 clones were selected with distinct sequences and high specificity to protective antigen and thus were the subject of a series of both biophysical and cell-based cytotoxicity assays. From this panel of antibodies a set of neutralizing antibodies were identified, of which clone A8 recognizes the lethal (and/or edema) factor binding domain, and clones F1, G11, and G12 recognize the cellular receptor binding domain found within the protective antigen. It was noted that all clones distinguish a conformational epitope existing on the protective antigen; this steric relationship was uncovered using a sequential epitope mapping approach. For each neutralizing antibody, the kinetic constants were determined by surface plasmon resonance, while the potency of protection was established using a two-tier macrophage cytotoxicity assay. Among the neutralizing antibodies identified, clone F1 possessed the highest affinity to protective antigen, and provided superior protection from lethal toxin in the cell cytotoxicity assay. The data presented provide the ever-growing arsenal of immunological and functional analysis of monoclonal antibodies to the exotoxins of anthrax. In addition it grants new candidates for the prophylaxis and therapeutic treatment against this toxin.
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Affiliation(s)
- Bin Zhou
- Department of Chemistry, Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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50
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Kelly CD, O'Loughlin C, Gelder FB, Peterson JW, Sower LE, Cirino NM. Rapid generation of an anthrax immunotherapeutic from goats using a novel non-toxic muramyl dipeptide adjuvant. JOURNAL OF IMMUNE BASED THERAPIES AND VACCINES 2007; 5:11. [PMID: 17953756 PMCID: PMC2104530 DOI: 10.1186/1476-8518-5-11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2007] [Accepted: 10/22/2007] [Indexed: 12/12/2022]
Abstract
BACKGROUND There is a clear need for vaccines and therapeutics for potential biological weapons of mass destruction and emerging diseases. Anthrax, caused by the bacterium Bacillus anthracis, has been used as both a biological warfare agent and bioterrorist weapon previously. Although antibiotic therapy is effective in the early stages of anthrax infection, it does not have any effect once exposed individuals become symptomatic due to B. anthracis exotoxin accumulation. The bipartite exotoxins are the major contributing factors to the morbidity and mortality observed in acute anthrax infections. METHODS Using recombinant B. anthracis protective antigen (PA83), covalently coupled to a novel non-toxic muramyl dipeptide (NT-MDP) derivative we hyper-immunized goats three times over the course of 14 weeks. Goats were plasmapheresed and the IgG fraction (not affinity purified) and F(ab')2 derivatives were characterized in vitro and in vivo for protection against lethal toxin mediated intoxication. RESULTS Anti-PA83 IgG conferred 100% protection at 7.5 mug in a cell toxin neutralization assay. Mice exposed to 5 LD50 of Bacillus anthracis Ames spores by intranares inoculation demonstrated 60% survival 14 d post-infection when administered a single bolus dose (32 mg/kg body weight) of anti-PA83 IgG at 24 h post spore challenge. Anti-PA83 F(ab')2 fragments retained similar neutralization and protection levels both in vitro and in vivo. CONCLUSION The protection afforded by these GMP-grade caprine immunotherapeutics post-exposure in the pilot murine model suggests they could be used effectively to treat post-exposure, symptomatic human anthrax patients following a bioterrorism event. These results also indicate that recombinant PA83 coupled to NT-MDP is a potent inducer of neutralizing antibodies and suggest it would be a promising vaccine candidate for anthrax. The ease of production, ease of covalent attachment, and immunostimulatory activity of the NT-MDP indicate it would be a superior adjuvant to alum or other traditional adjuvants in vaccine formulations.
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Affiliation(s)
- Cassandra D Kelly
- Wadsworth Center, New York State Department of Health, Biodefense Laboratory, Albany, NY, USA
- SUNY at Albany, School of Public Health, Department of Biomedical Sciences, Albany, NY, USA
| | | | | | | | - Laurie E Sower
- The University of Texas Medical Branch, Galveston, TX, USA
| | - Nick M Cirino
- Wadsworth Center, New York State Department of Health, Biodefense Laboratory, Albany, NY, USA
- SUNY at Albany, School of Public Health, Department of Biomedical Sciences, Albany, NY, USA
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