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Ali Dahhas M, Alsenaidy MA. Role of site-directed mutagenesis and adjuvants in the stability and potency of anthrax protective antigen. Saudi Pharm J 2022; 30:595-604. [PMID: 35693445 PMCID: PMC9177452 DOI: 10.1016/j.jsps.2022.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 02/21/2022] [Indexed: 11/03/2022] Open
Abstract
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.
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Kondakova OA, Nikitin NA, Evtushenko EA, Ryabchevskaya EM, Atabekov JG, Karpova OV. Vaccines against anthrax based on recombinant protective antigen: problems and solutions. Expert Rev Vaccines 2019; 18:813-828. [PMID: 31298973 DOI: 10.1080/14760584.2019.1643242] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Introduction: Anthrax is a dangerous bio-terror agent because Bacillus anthracis spores are highly resilient and can be easily aerosolized and disseminated. There is a threat of deliberate use of anthrax spores aerosol that could lead to serious fatal diseases outbreaks. Existing control measures against inhalation form of the disease are limited. All of this has provided an impetus to the development of new generation vaccines. Areas сovered: This review is devoted to challenges and achievements in the design of vaccines based on the anthrax recombinant protective antigen (rPA). Scientific databases have been searched, focusing on causes of PA instability and solutions to this problem, including new approaches of rPA expression, novel rPA-based vaccines formulations as well as the simultaneous usage of PA with other anthrax antigens. Expert opinion: PA is a central anthrax toxin component, playing a key role in the defense against encapsulated and unencapsulated strains. Subunit rPA-based vaccines have a good safety and protective profile. However, there are problems of PA instability that are greatly enhanced when using aluminum adjuvants. New adjuvant compositions, dry formulations and resistant to proteolysis and deamidation mutant PA forms can help to handle this issue. Devising a modern anthrax vaccine requires huge efforts.
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Affiliation(s)
- Olga A Kondakova
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Nikolai A Nikitin
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Ekaterina A Evtushenko
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Ekaterina M Ryabchevskaya
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Joseph G Atabekov
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
| | - Olga V Karpova
- a Department of Virology, Faculty of Biology, Lomonosov Moscow State University , Moscow , Russian Federation
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Kumar R, Feltrup TM, Kukreja RV, Patel KB, Cai S, Singh BR. Evolutionary Features in the Structure and Function of Bacterial Toxins. Toxins (Basel) 2019; 11:toxins11010015. [PMID: 30609803 PMCID: PMC6356308 DOI: 10.3390/toxins11010015] [Citation(s) in RCA: 15] [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: 11/02/2018] [Revised: 12/24/2018] [Accepted: 12/25/2018] [Indexed: 12/21/2022] Open
Abstract
Toxins can function both as a harmful and therapeutic molecule, depending on their concentrations. The diversity in their function allows us to ask some very pertinent questions related to their origin and roles: (a) What makes them such effective molecules? (b) Are there evolutionary features encoded within the structures of the toxins for their function? (c) Is structural hierarchy in the toxins important for maintaining their structure and function? (d) Do protein dynamics play a role in the function of toxins? and (e) Do the evolutionary connections to these unique features and functions provide the fundamental points in driving evolution? In light of the growing evidence in structural biology, it would be appropriate to suggest that protein dynamics and flexibility play a much bigger role in the function of the toxin than the structure itself. Discovery of IDPs (intrinsically disorder proteins), multifunctionality, and the concept of native aggregation are shaking the paradigm of the requirement of a fixed three-dimensional structure for the protein’s function. Growing evidence supporting the above concepts allow us to redesign the structure-function aspects of the protein molecules. An evolutionary model is necessary and needs to be developed to study these important aspects. The criteria for a well-defined model would be: (a) diversity in structure and function, (b) unique functionality, and (c) must belong to a family to define the evolutionary relationships. All these characteristics are largely fulfilled by bacterial toxins. Bacterial toxins are diverse and widely distributed in all three forms of life (Bacteria, Archaea and Eukaryotes). Some of the unique characteristics include structural folding, sequence and functional combination of domains, targeting a cellular process to execute their function, and most importantly their flexibility and dynamics. In this work, we summarize certain unique aspects of bacterial toxins, including role of structure in defining toxin function, uniqueness in their enzymatic function, and interaction with their substrates and other proteins. Finally, we have discussed the evolutionary aspects of toxins in detail, which will help us rethink the current evolutionary theories. A careful study, and appropriate interpretations, will provide answers to several questions related to the structure-function relationship of proteins, in general. Additionally, this will also allow us to refine the current evolution theories.
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Affiliation(s)
- Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
| | - Thomas M Feltrup
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
| | - Roshan V Kukreja
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
| | - Kruti B Patel
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
| | - Shuowei Cai
- Department of Chemistry and Biochemistry, University of Massachusetts, Dartmouth, MA 02747, USA.
| | - Bal Ram Singh
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA.
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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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Storm L, Bikker FJ, Nazmi K, Hulst AG, der Riet-Van Oeveren DV, Veerman ECI, Hays JP, Kaman WE. Anthrax protective antigen is a calcium-dependent serine protease. Virulence 2018; 9:1085-1091. [PMID: 30052476 PMCID: PMC6086315 DOI: 10.1080/21505594.2018.1486139] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Bacillus anthracis secretes a three component exotoxin-complex, which contributes to anthrax pathogenesis. Formation of this complex starts with the binding of protective antigen (PA) to its cellular receptor. In this study, we report that PA is a calcium-dependent serine protease and that the protein potentially uses this proteolytic activity for receptor binding. Additionally our findings shed new light on previous research describing the inhibition of anthrax toxins and exotoxin formation. Importantly, inhibition of the proteolytic activity of protective antigen could be a novel therapeutic strategy in fighting B. anthracis-related infections.
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Affiliation(s)
- Lisanne Storm
- a Department of Medical Microbiology and Infectious Diseases , Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Floris J Bikker
- b Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam , University of Amsterdam and VU University Amsterdam , Amsterdam , The Netherlands
| | - Kamran Nazmi
- b Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam , University of Amsterdam and VU University Amsterdam , Amsterdam , The Netherlands
| | - Albert G Hulst
- c Department of CBRN Protection , Netherlands Organization for Applied Scientific Research TNO , Rijswijk , The Netherlands
| | - Debora V der Riet-Van Oeveren
- c Department of CBRN Protection , Netherlands Organization for Applied Scientific Research TNO , Rijswijk , The Netherlands
| | - Enno C I Veerman
- b Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam , University of Amsterdam and VU University Amsterdam , Amsterdam , The Netherlands
| | - John P Hays
- a Department of Medical Microbiology and Infectious Diseases , Erasmus University Medical Centre , Rotterdam , The Netherlands
| | - Wendy E Kaman
- a Department of Medical Microbiology and Infectious Diseases , Erasmus University Medical Centre , Rotterdam , The Netherlands.,b Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam , University of Amsterdam and VU University Amsterdam , Amsterdam , The Netherlands
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Khandia R, Pattnaik B, Rajukumar K, Pateriya A, Bhatia S, Murugkar H, Prakash A, Pradhan HK, Dhama K, Munjal A, Joshi SK. Anti-proliferative role of recombinant lethal toxin of Bacillus anthracis on primary mammary ductal carcinoma cells revealing its therapeutic potential. Oncotarget 2018; 8:35835-35847. [PMID: 28415766 PMCID: PMC5482621 DOI: 10.18632/oncotarget.16214] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 03/07/2017] [Indexed: 12/11/2022] Open
Abstract
Bacillus anthracis secretes three secretary proteins; lethal factor (LF), protective antigen (PA) and edema factor (EF). The LF has ability to check proliferation of mammary tumors, chiefly depending on mitogen activated protein kinase (MAPK) signaling pathway. Evaluation of therapeutic potential of recombinant LF (rLF), recombinant PA (rPA) and lethal toxin (rLF + rPA = LeTx) on the primary mammary ductal carcinoma cells revealed significant (p < 0.01) reduction in proliferation of tumor cells with mean inhibition indices of 28.0 ± 1.37% and 19.6 ± 1.47% respectively. However, treatment with rPA alone had no significant anti-proliferative effect as evident by low mean inhibition index of 3.4 ± 3.87%. The higher inhibition index observed for rLF alone as compared to LeTx is contrary to the existing knowledge on LF, which explains the requirement of PA dependent endocytosis for its enzymatic activity. Therefore, the plausible existence of PA independent mode of action of LF including direct receptor mediated endocytosis or modulation of signal transduction cascade via unknown means is hypothesized. In silico protein docking analysis of other cellular receptors for any plausibility to play the role of receptor for LF revealed c-Met receptor showing strongest affinity for LF (H bond = 19; Free energy = −773.96), followed by nerve growth factor receptor (NGFR) and human epidermal growth factor receptor (HER)-1. The study summarizes the use of rLF or LeTx as therapeutic molecule against primary mammary ductal carcinoma cells and also the c-Met as potential alternative receptor for LF to mediate and modulate PA independent signal transduction.
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Affiliation(s)
- Rekha Khandia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India.,Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Bramhadev Pattnaik
- Project Directorate on Foot and Mouth Disease, Mukteswar, Uttarakhand, India
| | | | - Atul Pateriya
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Sandeep Bhatia
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Harshad Murugkar
- ICAR-National Institute of High Security Animal Diseases, Bhopal, Madhya Pradesh, India
| | - Anil Prakash
- Department of Microbiology, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Hare Krishna Pradhan
- Ex-Avian Influenza National Consultant, Indian Office of WHO Consultant, Bhartiya Kala Kendra, New Delhi, India
| | - Kuldeep Dhama
- Division of Pathology, ICAR-Indian Veterinary Research Institute, Izatnagar, Bareilly Uttar Pradesh, India
| | - Ashok Munjal
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, Madhya Pradesh, India
| | - Sunil K Joshi
- Cellular Immunology Laboratory, Frank Reidy Research Center of Bioelectrics, College of Health Sciences, Old Dominion University Norfolk, VA USA
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Suffredini DA, Cui X, Xu W, Li Y, Eichacker PQ. The Potential Pathogenic Contributions of Endothelial Barrier and Arterial Contractile Dysfunction to Shock Due to B. anthracis Lethal and Edema Toxins. Toxins (Basel) 2017; 9:toxins9120394. [PMID: 29210983 PMCID: PMC5744114 DOI: 10.3390/toxins9120394] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 11/24/2017] [Accepted: 11/29/2017] [Indexed: 01/22/2023] Open
Abstract
Shock with B. anthracis infection is particularly resistant to conventional cardiovascular support and its mortality rate appears higher than with more common bacterial pathogens. As opposed to many bacteria that lack exotoxins directly depressing hemodynamic function, lethal and edema toxin (LT and ET respectively) both cause shock and likely contribute to the high lethality rate with B. anthracis. Selective inhibition of the toxins is protective in infection models, and administration of either toxin alone in animals produces hypotension with accompanying organ injury and lethality. Shock during infection is typically due to one of two mechanisms: (i) intravascular volume depletion related to disruption of endothelial barrier function; and (ii) extravasation of fluid and/or maladaptive dilation of peripheral resistance arteries. Although some data suggests that LT can produce myocardial dysfunction, growing evidence demonstrates that it may also interfere with endothelial integrity thereby contributing to the extravasation of fluid that helps characterize severe B. anthracis infection. Edema toxin, on the other hand, while known to produce localized tissue edema when injected subcutaneously, has potent vascular relaxant effects that could lead to pathologic arterial dilation. This review will examine recent data supporting a role for these two pathophysiologic mechanisms underlying the shock LT and ET produce. Further research and a better understanding of these mechanisms may lead to improved management of B. anthracis in patients.
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Affiliation(s)
- Dante A Suffredini
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Building 10, Room 2C145, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Xizhong Cui
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Building 10, Room 2C145, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Wanying Xu
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Building 10, Room 2C145, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Yan Li
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Building 10, Room 2C145, 9000 Rockville Pike, Bethesda, MD 20892, USA.
| | - Peter Q Eichacker
- Critical Care Medicine Department, Clinical Center, National Institutes of Health, Building 10, Room 2C145, 9000 Rockville Pike, Bethesda, MD 20892, USA.
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Evaluation of Combination Drug Therapy for Treatment of Antibiotic-Resistant Inhalation Anthrax in a Murine Model. Antimicrob Agents Chemother 2017; 61:AAC.00788-17. [PMID: 28696235 DOI: 10.1128/aac.00788-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 07/02/2017] [Indexed: 12/29/2022] Open
Abstract
Bacillus anthracis is considered a likely agent to be used as a bioweapon, and the use of a strain resistant to the first-line antimicrobial treatments is a concern. We determined treatment efficacies against a ciprofloxacin-resistant strain of B. anthracis (Cipr Ames) in a murine inhalational anthrax model. Ten groups of 46 BALB/c mice were exposed by inhalation to 7 to 35 times the 50% lethal dose (LD50) of B. anthracis Cipr Ames spores. Commencing at 36 h postexposure, groups were administered intraperitoneal doses of sterile water for injections (SWI) and ciprofloxacin alone (control groups), or ciprofloxacin combined with two antimicrobials, including meropenem-linezolid, meropenem-clindamycin, meropenem-rifampin, meropenem-doxycycline, penicillin-linezolid, penicillin-doxycycline, rifampin-linezolid, and rifampin-clindamycin, at appropriate dosing intervals (6 or 12 h) for the respective antibiotics. Ten mice per group were treated for 14 days and observed until day 28. The remaining animals were euthanized every 6 to 12 h, and blood, lungs, and spleens were collected for lethal factor (LF) and/or bacterial load determinations. All combination groups showed significant survival over the SWI and ciprofloxacin controls: meropenem-linezolid (P = 0.004), meropenem-clindamycin (P = 0.005), meropenem-rifampin (P = 0.012), meropenem-doxycycline (P = 0.032), penicillin-doxycycline (P = 0.012), penicillin-linezolid (P = 0.026), rifampin-linezolid (P = 0.001), and rifampin-clindamycin (P = 0.032). In controls, blood, lung, and spleen bacterial counts increased to terminal endpoints. In combination treatment groups, blood and spleen bacterial counts showed low/no colonies after 24-h treatments. The LF fell below the detection limits for all combination groups yet remained elevated in control groups. Combinations with linezolid had the greatest inhibitory effect on mean LF levels.
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Does Bacillus anthracis Lethal Toxin Directly Depress Myocardial Function? A Review of Clinical Cases and Preclinical Studies. Toxins (Basel) 2015; 7:5417-34. [PMID: 26703730 PMCID: PMC4690141 DOI: 10.3390/toxins7124891] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 11/24/2015] [Accepted: 12/07/2015] [Indexed: 12/17/2022] Open
Abstract
The US outbreak of B.anthracis infection in 2001 and subsequent cases in the US and Europe demonstrate that anthrax is a continuing risk for the developed world. While several bacterial components contribute to the pathogenesis of B. anthracis, production of lethal toxin (LT) is strongly associated with the development of hypotension and lethality. However, the mechanisms underlying the cardiovascular instability LT produces are unclear. Some evidence suggests that LT causes shock by impairing the peripheral vasculature, effects consistent with the substantial extravasation of fluid in patients dying with B. anthracis. Other data suggests that LT directly depresses myocardial function. However a clinical correlate for this latter possibility is less evident since functional studies and post-mortem examination in patients demonstrate absent or minimal cardiac changes. The purposes of this review were to first present clinical studies of cardiac functional and histologic pathology with B. anthracis infection and to then examine in vivo, in vitro, and ex vivo preclinical studies of LT’s myocardial effects. Together, these data suggest that it is unclear whether that LT directly depresses cardiac function. This question is important for the clinical management and development of new therapies for anthrax and efforts should continue to be made to answer it.
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Xiong S, Tang Q, Liang X, Zhou T, Yang J, Liu P, Chen Y, Wang C, Feng Z, Zhu J. A Novel Chimeric Anti-PA Neutralizing Antibody for Postexposure Prophylaxis and Treatment of Anthrax. Sci Rep 2015; 5:11776. [PMID: 26134518 PMCID: PMC4488766 DOI: 10.1038/srep11776] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 05/28/2015] [Indexed: 12/11/2022] Open
Abstract
Anthrax is a highly lethal infectious disease caused by the bacterium Bacillus anthracis, and the associated shock is closely related to the lethal toxin (LeTx) produced by the bacterium. The central role played by the 63 kDa protective antigen (PA63) region of LeTx in the pathophysiology of anthrax makes it an excellent therapeutic target. In the present study, a human/murine chimeric IgG mAb, hmPA6, was developed by inserting murine antibody variable regions into human constant regions using antibody engineering technology. hmPA6 expressed in 293F cells could neutralize LeTx both in vitro and in vivo. At a dose of 0.3 mg/kg, it could protect all tested rats from a lethal dose of LeTx. Even administration of 0.6 mg/kg hmPA6 48 h before LeTx challenge protected all tested rats. The results indicate that hmPA6 is a potential candidate for clinical application in anthrax treatment.
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Affiliation(s)
- Siping Xiong
- 1] Department of Pathology, Nanjing Medical University, Nanjing 210029, China [2] Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
| | - Qi Tang
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
| | - Xudong Liang
- National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206 China
| | - Tingting Zhou
- Huadong Medical Institute of Biotechniques, Nanjing 210002, China
| | - Jin Yang
- Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
| | - Peng Liu
- Huadong Medical Institute of Biotechniques, Nanjing 210002, China
| | - Ya Chen
- 1] Department of Pathology, Nanjing Medical University, Nanjing 210029, China [2] Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
| | - Changjun Wang
- Huadong Medical Institute of Biotechniques, Nanjing 210002, China
| | - Zhenqing Feng
- 1] Department of Pathology, Nanjing Medical University, Nanjing 210029, China [2] Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
| | - Jin Zhu
- 1] Huadong Medical Institute of Biotechniques, Nanjing 210002, China [2] Key Laboratory of Antibody Technique of Ministry of Health, Nanjing Medical University, Nanjing 210029, China
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Kim BJ, Hancock BM, Bermudez A, Del Cid N, Reyes E, van Sorge NM, Lauth X, Smurthwaite CA, Hilton BJ, Stotland A, Banerjee A, Buchanan J, Wolkowicz R, Traver D, Doran KS. Bacterial induction of Snail1 contributes to blood-brain barrier disruption. J Clin Invest 2015; 125:2473-83. [PMID: 25961453 DOI: 10.1172/jci74159] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 04/06/2015] [Indexed: 12/23/2022] Open
Abstract
Bacterial meningitis is a serious infection of the CNS that results when blood-borne bacteria are able to cross the blood-brain barrier (BBB). Group B Streptococcus (GBS) is the leading cause of neonatal meningitis; however, the molecular mechanisms that regulate bacterial BBB disruption and penetration are not well understood. Here, we found that infection of human brain microvascular endothelial cells (hBMECs) with GBS and other meningeal pathogens results in the induction of host transcriptional repressor Snail1, which impedes expression of tight junction genes. Moreover, GBS infection also induced Snail1 expression in murine and zebrafish models. Tight junction components ZO-1, claudin 5, and occludin were decreased at both the transcript and protein levels in hBMECs following GBS infection, and this repression was dependent on Snail1 induction. Bacteria-independent Snail1 expression was sufficient to facilitate tight junction disruption, promoting BBB permeability to allow bacterial passage. GBS induction of Snail1 expression was dependent on the ERK1/2/MAPK signaling cascade and bacterial cell wall components. Finally, overexpression of a dominant-negative Snail1 homolog in zebrafish elevated transcription of tight junction protein-encoding genes and increased zebrafish survival in response to GBS challenge. Taken together, our data support a Snail1-dependent mechanism of BBB disruption and penetration by meningeal pathogens.
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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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Preparation and evaluation of human-murine chimeric antibody against protective antigen of Bacillus anthracis. Int J Mol Sci 2014; 15:18496-507. [PMID: 25318053 PMCID: PMC4227228 DOI: 10.3390/ijms151018496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/25/2014] [Accepted: 09/30/2014] [Indexed: 12/24/2022] Open
Abstract
The aim of this research is to develop a human/murine chimeric Fab antibody which neutralizes the anthrax toxin, protective antigen (PA). The chimeric Fab was constructed using variable regions of murine anti-PA monoclonal antibody in combination with constant regions of human IgG. The chimeric PA6-Fab was expressed in E. coli. BL21 and evaluated by ELISA and co-immunoprecipitation- mass spectra. The potency of PA6-Fab to neutralize LeTx was examined in J774A.1 cell viability in vitro and in Fisher 344 rats in vivo. The PA6-Fab did not have domain similarity corresponding to the current anti PA mAbs, but specifically bound to anthrax PA at an affinity of 1.76 nM, and was able to neutralize LeTx in vitro and protected 56.9% cells at 20 μg/mL against anthrax LeTx. One hundred μg PA6-Fab could neutralize 300 μg LeTx in vivo. The PA6-Fab has potential as a therapeutic mAb for treatment of anthrax.
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A human/murine chimeric fab antibody neutralizes anthrax lethal toxin in vitro. Clin Dev Immunol 2013; 2013:475809. [PMID: 23861692 PMCID: PMC3687597 DOI: 10.1155/2013/475809] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 05/12/2013] [Accepted: 05/13/2013] [Indexed: 12/21/2022]
Abstract
Human anthrax infection caused by exposure to Bacillus anthracis cannot always be treated by antibiotics. This is mostly because of the effect of the remaining anthrax toxin in the body. Lethal factor (LF) is a component of lethal toxin (LeTx), which is the major virulence of anthrax toxin. A murine IgG monoclonal antibody (mAb) against LF with blocking activity (coded LF8) was produced in a previous study. In this report, a human/murine chimeric Fab mAb (coded LF8-Fab) was developed from LF8 by inserting murine variable regions into human constant regions using antibody engineering to reduce the incompatibility of the murine antibody for human use. The LF8-Fab expressed in Escherichia coli could specifically identify LF with an affinity of 3.46 × 107 L/mol and could neutralize LeTx with an EC50 of 85 μg/mL. Even after LeTx challenge at various time points, the LF8-Fab demonstrated protection of J774A.1 cells in vitro. The results suggest that the LF8-Fab might be further characterized and potentially be used for clinical applications against anthrax infection.
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Smoum R, Rubinstein A, Dembitsky VM, Srebnik M. Boron containing compounds as protease inhibitors. Chem Rev 2012; 112:4156-220. [PMID: 22519511 DOI: 10.1021/cr608202m] [Citation(s) in RCA: 298] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Reem Smoum
- The School of Pharmacy, Institute for Drug Research, The Hebrew University of Jerusalem, Faculty of Medicine, Jerusalem, Israel.
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