1
|
Fonfria E, Marks E, Foulkes LM, Schofield R, Higazi D, Coward S, Kippen A. Replacement of the Mouse LD 50 Assay for Determination of the Potency of AbobotulinumtoxinA with a Cell-Based Method in Both Powder and Liquid Formulations. Toxins (Basel) 2023; 15:toxins15050314. [PMID: 37235349 DOI: 10.3390/toxins15050314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 04/18/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are important therapeutic agents. The in vivo median lethal dose (LD50) assay has been commonly used to measure the potency of BoNT commercial preparations. As an alternative, we developed cell-based assays for abobotulinumtoxinA in both powder (Dysport®, Azzalure®) and liquid (Alluzience®) formulations using the in vitro BoCell® system. The assays demonstrated linearity over 50-130% of the expected relative potency, with a correlation coefficient of 0.98. Mean recoveries of 90-108% of the stated potency were observed over this range. The coefficients of variation for powder and liquid formulations, respectively, were 3.6% and 4.0% for repeatability and 8.3% and 5.0% for intermediate precision. A statistically powered comparability assessment of the BoCell® and LD50 assays was performed. Equivalence was demonstrated between the assays for the liquid formulation at release and end of shelf life using a paired equivalence test with predefined equivalence margins. For the powder formulation, the assays were also shown to be equivalent for release samples and when determining loss of potency following thermal degradation. The BoCell® assay was approved for establishing the potency of abobotulinumtoxinA for both powder and liquid formulations in Europe and for the powder formulation only in the USA.
Collapse
Affiliation(s)
| | | | | | | | | | - Sam Coward
- Ipsen Biopharm Ltd., Wrexham LL13 9UF, UK
| | | |
Collapse
|
2
|
Ambrin G, Cai S, Singh BR. Critical analysis in the advancement of cell-based assays for botulinum neurotoxin. Crit Rev Microbiol 2023; 49:1-17. [PMID: 35212259 DOI: 10.1080/1040841x.2022.2035315] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The study on botulinum neurotoxins (BoNTs) has rapidly evolved for their structure and functions as opposed to them being poisons or cures. Since their discoveries, the scientific community has come a long way in understanding BoNTs' structure and biological activity. Given its current application as a tool for understanding neurocellular activity and as a drug against over 800 neurological disorders, relevant and sensitive assays have become critical for biochemical, physiological, and pharmacological studies. The natural entry of the toxin being ingestion, it has also become important to examine its mechanism while crossing the epithelial cell barrier. Several techniques and methodologies have been developed, for its entry, pharmacokinetics, and biological activity for identification, and drug efficacy both in vivo and in vitro conditions. However, each of them presents its own challenges. The cell-based assay is a platform that exceeds the sensitivity of mouse bioassay while encompassing all the steps of intoxication including cell binding, transcytosis, endocytosis, translocation and proteolytic activity. In this article we review in detail both the neuronal and nonneuronal based cellular interaction of BoNT involving its transportation, and interaction with the targeted cells, and intracellular activities.
Collapse
Affiliation(s)
- Ghuncha Ambrin
- Department of Biomedical Engineering and Biotechnology, University of Massachusetts, Dartmouth, MA, USA.,Department of Chemistry and Biochemistry, University of Massachusetts, Dartmouth, MA, USA
| | - Shuowei Cai
- Department of Chemistry and Biochemistry, University of Massachusetts, Dartmouth, MA, USA
| | - Bal Ram Singh
- Institute of Advanced Sciences, Botulinum Research Center, Dartmouth, MA, USA
| |
Collapse
|
3
|
Botulinum toxin antibody titres: measurement, interpretation, and practical recommendations. J Neurol 2023; 270:1524-1530. [PMID: 36434127 PMCID: PMC9971068 DOI: 10.1007/s00415-022-11424-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 11/27/2022]
Abstract
Botulinum toxin (BT) therapy may be blocked by antibodies (BT-AB) resulting in BT-AB induced therapy failure (ABF). BT-AB may be detected by the mouse lethality assay (MLA), the mouse diaphragm assay (MDA) and the sternocleidomastoid test (SCMT). For the first time, we wanted to compare all three BT-AB tests and correlate them to subjective complaint of complete or partial secondary therapy failure in 37 patients with cervical dystonia (25 females, 12 males, age 51.2 ± 11.4 years, disease duration 12.4 ± 6.3 years). Complaint of therapy failure was not correlated with any of the BT-AB tests. MDA and MLA are closely correlated, indicating that the MDA might replace the MLA as the current gold standard for BT-AB measurement. The SCMT is closely correlated with MDA and MLA confirming that BT-AB titres and BT's paretic effect are in a functional balance: low BT-AB titres are reducing BT's paretic effect only marginally, whereas high BT-AB titres may completely block it. When therapy failure is classified as secondary and permanent, BT-AB evaluation is recommended and any BT-AB test may be applied. For MDA > 10 mU/ml, MLA > 3 and SCMT < 25%, ABF is highly likely. MDA < 0.6 mU/ml are therapeutically irrelevant. They are neither correlated with pathologic MLA nor with pathologic SCMT. They should not be the basis for treatment decisions, such as switching dystonia therapy to deep brain stimulation. All other results are intermediate results. Their interactions with therapy efficacy is unpredictable. In these cases, BT-AB tests should be repeated or one or two additional test methods should be applied.
Collapse
|
4
|
Rasetti-Escargueil C, Popoff MR. Recent Developments in Botulinum Neurotoxins Detection. Microorganisms 2022; 10:microorganisms10051001. [PMID: 35630444 PMCID: PMC9145529 DOI: 10.3390/microorganisms10051001] [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: 04/01/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are produced as protein complexes by bacteria of the genus Clostridium that are Gram-positive, anaerobic and spore forming (Clostridium botulinum, C. butyricum, C. baratii and C. argentinense spp.). BoNTs show a high immunological and genetic diversity. Therefore, fast, precise, and more reliable detection methods are still required to monitor outbreaks and ensure surveillance of botulism. The botulinum toxin field also comprises therapeutic uses, basic research studies and biodefense issues. This review presents currently available detection methods, and new methods offering the potential of enhanced precision and reproducibility. While the immunological methods offer a range of benefits, such as rapid analysis time, reproducibility and high sensitivity, their implementation is subject to the availability of suitable tools and reagents, such as specific antibodies. Currently, the mass spectrometry approach is the most sensitive in vitro method for a rapid detection of active or inactive forms of BoNTs. However, these methods require inter-laboratory validation before they can be more widely implemented in reference laboratories. In addition, these surrogate in vitro models also require full validation before they can be used as replacement bioassays of potency. Cell-based assays using neuronal cells in culture recapitulate all functional steps of toxin activity, but are still at various stages of development; they are not yet sufficiently robust, due to high batch-to-batch cell variability. Cell-based assays have a strong potential to replace the mouse bioassay (MBA) in terms of BoNT potency determination in pharmaceutical formulations; they can also help to identify suitable inhibitors while reducing the number of animals used. However, the development of safe countermeasures still requires the use of in vivo studies to complement in vitro immunological or cell-based approaches.
Collapse
|
5
|
Dressler D, Johnson EA. Botulinum toxin therapy: past, present and future developments. J Neural Transm (Vienna) 2022; 129:829-833. [PMID: 35396965 PMCID: PMC9188496 DOI: 10.1007/s00702-022-02494-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 03/23/2022] [Indexed: 12/17/2022]
Abstract
Although botulinum toxin (BT) is now being used in a large number of different indications in numerous medical specialties, there is still dynamic and rapid development. Treatment algorithms were improved by the introduction of BT short-interval therapy, BT high-dose therapy and improved dosing guidelines. Ultrasound guidance may be helpful in special situations. New indication areas including depression and inflammatory processes are being explored. Drug development projects are mainly focusing on onabotulinumtoxinA analogues, some are addressing liquid preparations and modifications of BT's duration of action. Recombinant BT may simplify production processes. Cell-based assays for potency measurement will soon be required by registration authorities. Treatment algorithms will be further refined and indications will be expanded. New indication areas are still uncertain. BT type A will remain the drug substance of choice. Removal of complexing proteins seems logical. Whether there is a need for BT drugs with modified duration of action and for liquid preparations, is unclear. Bringing BT therapy to those who need it, is the biggest challenge. Current high-price business models need to be changed, either by employing a biosimilar registration approach or by referring to companies from countries where business models are based on different cost structures.
Collapse
Affiliation(s)
- Dirk Dressler
- Movement Disorders Section, Department of Neurology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Eric A Johnson
- Botulinum Toxins Laboratory, Department of Bacteriology, University of Wisconsin, Madison, WI, USA
| |
Collapse
|
6
|
Transferability study of the BINACLE (binding and cleavage) assay for in vitro determination of botulinum neurotoxin activity. Biologicals 2020; 67:81-87. [PMID: 32739117 DOI: 10.1016/j.biologicals.2020.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/24/2020] [Accepted: 06/28/2020] [Indexed: 11/23/2022] Open
Abstract
The muscle-relaxing effects of the botulinum neurotoxin (BoNT) serotypes A and B are widely used in clinical and aesthetic medicine. The standard method for measuring the biological activity of pharmaceutical BoNT products is a mouse bioassay. In line with the European Directive 2010/63/EU, a replacement by an animal-free method would be desirable. Whereas the existing approved in vitro methods for BoNT activity measurements are product-specific and not freely available for all users, the "binding and cleavage" (BINACLE) assay could become a widely applicable alternative. This method quantifies active BoNT molecules based on their specific receptor-binding and proteolytic properties and can be applied to all BoNT products on the European market. Here we describe the results of a transferability study, in which identical BoNT samples were tested in the BINACLE assay in four laboratories. All participants successfully performed the method and observed clear dose-response relationships. Assay variability was within an acceptable range. These data indicate that the BoNT BINACLE assay is robust and can be straightforwardly transferred between laboratories. They thus provide an appropriate basis for future studies to further substantiate the suitability of the BINACLE assay for the potency determination of BoNT products.
Collapse
|
7
|
Schenke M, Schjeide BM, Püschel GP, Seeger B. Analysis of Motor Neurons Differentiated from Human Induced Pluripotent Stem Cells for the Use in Cell-Based Botulinum Neurotoxin Activity Assays. Toxins (Basel) 2020; 12:toxins12050276. [PMID: 32344847 PMCID: PMC7291138 DOI: 10.3390/toxins12050276] [Citation(s) in RCA: 12] [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: 02/12/2020] [Revised: 04/12/2020] [Accepted: 04/23/2020] [Indexed: 01/03/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are potent neurotoxins produced by bacteria, which inhibit neurotransmitter release, specifically in their physiological target known as motor neurons (MNs). For the potency assessment of BoNTs produced for treatment in traditional and aesthetic medicine, the mouse lethality assay is still used by the majority of manufacturers, which is ethically questionable in terms of the 3Rs principle. In this study, MNs were differentiated from human induced pluripotent stem cells based on three published protocols. The resulting cell populations were analyzed for their MN yield and their suitability for the potency assessment of BoNTs. MNs produce specific gangliosides and synaptic proteins, which are bound by BoNTs in order to be taken up by receptor-mediated endocytosis, which is followed by cleavage of specific soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) proteins required for neurotransmitter release. The presence of receptors and substrates for all BoNT serotypes was demonstrated in MNs generated in vitro. In particular, the MN differentiation protocol based on Du et al. yielded high numbers of MNs in a short amount of time with high expression of BoNT receptors and targets. The resulting cells are more sensitive to BoNT/A1 than the commonly used neuroblastoma cell line SiMa. MNs are, therefore, an ideal tool for being combined with already established detection methods.
Collapse
Affiliation(s)
- Maren Schenke
- Institute for Food Toxicology, Department of Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine, 30173 Hannover, Germany;
| | - Brit-Maren Schjeide
- Institute of Nutritional Science, Department of Nutritional Biochemistry, University of Potsdam, 14558 Nuthetal, Germany; (B.-M.S.); (G.P.P.)
| | - Gerhard P. Püschel
- Institute of Nutritional Science, Department of Nutritional Biochemistry, University of Potsdam, 14558 Nuthetal, Germany; (B.-M.S.); (G.P.P.)
| | - Bettina Seeger
- Institute for Food Toxicology, Department of Food Toxicology and Replacement/Complementary Methods to Animal Testing, University of Veterinary Medicine, 30173 Hannover, Germany;
- Correspondence:
| |
Collapse
|
8
|
Chang J, Hu J, Li CSR, Yu R. Neural correlates of enhanced response inhibition in the aftermath of stress. Neuroimage 2020; 204:116212. [PMID: 31546050 PMCID: PMC7509808 DOI: 10.1016/j.neuroimage.2019.116212] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 09/12/2019] [Accepted: 09/18/2019] [Indexed: 12/25/2022] Open
Abstract
Life stress has been shown to impact cognitive functions, including inhibitory control. However, the immediate effects of acute stress on inhibitory control and the underlying neural mechanisms remain unclear. In a behavioral pilot study (N = 30) and a within-subject functional magnetic resonance imaging study (N = 30), we examined how acute stress induced by Trier Social Stress Test influenced inhibitory control in a stop signal task. Behavioral results across two studies showed that stress consistently improved inhibitory control. Shorter stop signal reaction time (SSRT) in stress as compared with control condition was associated with stronger connectivity between the superior/middle frontal gyrus (SFG/MFG) and striatum. Dynamic causal modeling revealed distinct best models under stress and control condition, with an enhanced interaction between the SFG/MFG and the striatum after stress exposure. This research identified the SFG/MFG-striatum network as a key circuit underlying acute stress-elicited enhancement of inhibitory control in a stop signal task.
Collapse
Affiliation(s)
- Jingjing Chang
- Guangdong Key Laboratory of Mental Health and Cognitive Science, Center for Studies of Psychological Application, School of Psychology, South China Normal University, Guangzhou, China
| | - Jianping Hu
- Laboratory for Behavioral and Regional Finance, Guangdong University of Finance, Guangzhou, China
| | - Chiang-Shan R Li
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA; Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Rongjun Yu
- Department of Psychology, National University of Singapore, Singapore.
| |
Collapse
|
9
|
Pellett S, Tepp WH, Johnson EA. Critical Analysis of Neuronal Cell and the Mouse Bioassay for Detection of Botulinum Neurotoxins. Toxins (Basel) 2019; 11:toxins11120713. [PMID: 31817843 PMCID: PMC6950160 DOI: 10.3390/toxins11120713] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 12/14/2022] Open
Abstract
Botulinum Neurotoxins (BoNTs) are a large protein family that includes the most potent neurotoxins known to humankind. BoNTs delivered locally in humans at low doses are widely used pharmaceuticals. Reliable and quantitative detection of BoNTs is of paramount importance for the clinical diagnosis of botulism, basic research, drug development, potency determination, and detection in clinical, environmental, and food samples. Ideally, a definitive assay for BoNT should reflect the activity of each of the four steps in nerve intoxication. The in vivo mouse bioassay (MBA) is the ‘gold standard’ for the detection of BoNTs. The MBA is sensitive, robust, semi-quantitative, and reliable within its sensitivity limits. Potential drawbacks with the MBA include assay-to-assay potency variations, especially between laboratories, and false positives or negatives. These limitations can be largely avoided by careful planning and performance. Another detection method that has gained importance in recent years for research and potency determination of pharmaceutical BoNTs is cell-based assays, as these assays can be highly sensitive, quantitative, human-specific, and detect fully functional holotoxins at physiologically relevant concentrations. A myriad of other in vitro BoNT detection methods exist. This review focuses on critical factors and assay limitations of the mouse bioassay and cell-based assays for BoNT detection.
Collapse
|
10
|
Weingart OG, Eyer K, Lüchtenborg C, Sachsenheimer T, Brügger B, van Oostrum M, Wollscheid B, Dittrich PS, Loessner MJ. In vitro quantification of botulinum neurotoxin type A1 using immobilized nerve cell-mimicking nanoreactors in a microfluidic platform. Analyst 2019; 144:5755-5765. [PMID: 31433410 DOI: 10.1039/c9an00817a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The bacterial toxin botulinum neurotoxin A (BoNT/A) is not only an extremely toxic substance but also a potent pharmaceutical compound that is used in a wide spectrum of neurological disorders and cosmetic applications. The quantification of the toxin is extremely challenging due to its extraordinary high physiological potency and is further complicated by the toxin's three key functionalities that are necessary for its activity: receptor binding, internalization-translocation, and catalytic activity. So far, the industrial standard to measure the active toxin has been the mouse bioassay (MBA) that is considered today as outdated due to ethical issues. Therefore, recent introductions of cell-based assays were highly anticipated; their impact however remains limited due to their labor-intensive implementation. This report describes a new in vitro approach that combines a nanosensor based on the use of nerve cell-mimicking nanoreactors (NMN) with microfluidic technology. The nanosensor was able to measure all three key functionalities, and therefore suitable to quantify the amount of physiologically active BoNT/A. The integration of such a sensor in a microfluidic device allowed the detection and quantification of BoNT/A amounts in a much shorter time than the MBA (<10 h vs. 2-4 days). Lastly, the system was also able to reliably quantify physiologically active BoNT/A within a simple final pharmaceutical formulation. This complete in vitro testing system and its unique combination of a highly sensitive nanosensor and microfluidic technology represent a significant ethical advancement over in vivo measures and a possible alternative to cell-based in vitro detection methods.
Collapse
Affiliation(s)
- Oliver G Weingart
- Institute for Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Content/Potency Assessment of Botulinum Neurotoxin Type-A by Validated Liquid Chromatography Methods and Bioassays. Toxins (Basel) 2019; 11:toxins11010035. [PMID: 30642048 PMCID: PMC6356430 DOI: 10.3390/toxins11010035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/28/2018] [Accepted: 01/10/2019] [Indexed: 01/16/2023] Open
Abstract
Botulinum neurotoxin type-A (BoNTA) is one of the seven different serotypes (A to G) produced by Clostridium botulinum. A stability-indicating size-exclusion chromatography (SEC) method was developed and validated, and the specificity was confirmed by forced degradation study, interference of the excipients, and peaks purity. The method was applied to assess the content and high-molecular-weight (HMW) forms of BoNTA in biopharmaceutical products, and the results were compared with those of the LD50 mouse bioassay, the T−47D cell culture assay, and the reversed-phase chromatography (RPC) method, giving mean values of 0.71% higher, 0.36% lower, and 0.87% higher, respectively. Aggregated forms showed significant effects on cytotoxicity, as well as a decrease in the bioactivity (p < 0.05). The employment of the proposed method in conjunction with the optimized analytical technologies for the analysis of the intact and altered forms of the biotechnology-derived medicines, in the correlation studies, enabled the demonstration of the capability of each one of the methods and allowed for great improvements, thereby assuring their safe and effective use.
Collapse
|
12
|
Thirunavukkarasu N, Johnson E, Pillai S, Hodge D, Stanker L, Wentz T, Singh B, Venkateswaran K, McNutt P, Adler M, Brown E, Hammack T, Burr D, Sharma S. Botulinum Neurotoxin Detection Methods for Public Health Response and Surveillance. Front Bioeng Biotechnol 2018; 6:80. [PMID: 29988463 PMCID: PMC6024544 DOI: 10.3389/fbioe.2018.00080] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/30/2018] [Indexed: 01/06/2023] Open
Abstract
Botulism outbreak due to consumption of food contaminated with botulinum neurotoxins (BoNTs) is a public health emergency. The threat of bioterrorism through deliberate distribution in food sources and/or aerosolization of BoNTs raises global public health and security concerns due to the potential for high mortality and morbidity. Rapid and reliable detection methods are necessary to support clinical diagnosis and surveillance for identifying the source of contamination, performing epidemiological analysis of the outbreak, preventing and responding to botulism outbreaks. This review considers the applicability of various BoNT detection methods and examines their fitness-for-purpose in safeguarding the public health and security goals.
Collapse
Affiliation(s)
- Nagarajan Thirunavukkarasu
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Eric Johnson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States
| | - Segaran Pillai
- U.S. Food and Drug Administration Office of Laboratory Science and Safety, Silver Spring, MD, United States
| | - David Hodge
- Chemical and Biological Defense Division, Science and Technology Directorate, U.S. Department of Homeland Security, Washington, DC, United States
| | - Larry Stanker
- U.S. Department of Agriculture, Agriculture Research Service Albany, Albany, CA, United States
| | - Travis Wentz
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - BalRam Singh
- Institute of Advanced Sciences, Botulinum Research Center, Dartmouth, MA, United States
| | | | - Patrick McNutt
- United States Army Medical Research Institute of Chemical Defense, Aberdeen, MD, United States
| | - Michael Adler
- United States Army Medical Research Institute of Chemical Defense, Aberdeen, MD, United States
| | - Eric Brown
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Thomas Hammack
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| | - Donald Burr
- Office of Regulatory Affairs, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, Silver Spring, MD, United States
| | - Shashi Sharma
- Division of Microbiology, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, MD, United States
| |
Collapse
|
13
|
Samizadeh S, De Boulle K. Botulinum neurotoxin formulations: overcoming the confusion. Clin Cosmet Investig Dermatol 2018; 11:273-287. [PMID: 29910630 PMCID: PMC5988049 DOI: 10.2147/ccid.s156851] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Botulinum toxin A is produced by anaerobic spore-forming bacteria and is used for various therapeutic and cosmetic purposes. Botulinum toxin A injections are the most popular nonsurgical procedure worldwide. Despite an increased demand for botulinum toxin A injections, the clinical pharmacology and differences in formulation of commonly available products are poorly understood. The various products available in the market are unique and vary in terms of units, chemical properties, biological activities, and weight, and are therefore not interchangeable. For safe clinical practice and to achieve optimal results, the practitioners need to understand the clinical issues of potency, conversion ratio, and safety issues (toxin spread and immunogenicity). In this paper, the basic clinical pharmacology of botulinum toxin A and differences between onabotulinum toxin A, abobotulinum toxin A, and incobotulinum toxin A are discussed.
Collapse
|
14
|
Rust A, Doran C, Hart R, Binz T, Stickings P, Sesardic D, Peden AA, Davletov B. A Cell Line for Detection of Botulinum Neurotoxin Type B. Front Pharmacol 2017; 8:796. [PMID: 29170639 PMCID: PMC5684488 DOI: 10.3389/fphar.2017.00796] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 10/20/2017] [Indexed: 01/29/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) type A and type B are commonly used as biopharmaceutics for neurological diseases, uniquely allowing months-long paralysis of target muscles. Their exquisite neuronal specificity is conferred by a multistep process of binding, internalization, cytosolic escape and cleavage of the neuron-specific proteins, SNAP-25 and vesicle-associated membrane proteins (VAMPs), ultimately to inhibit secretion of neurotransmitters. Currently the mouse lethality bioassay is the only available method for quality control testing of VAMP-cleaving botulinum products. Refined assays for botulinum product testing are urgently needed. Specifically, in vitro replacement assays which can account for all steps of BoNT intoxication are in high demand. Here, we describe a novel SiMa cell-based approach where re-engineering of the VAMP molecule allows detection of all BoNT/B intoxication steps using a luminescent enzymatic reaction with sensitivity comparable to mouse LD50 bioassay. The presented one-step enzyme-linked immunosorbent assay meets 3Rs (replacement, reduction, and refinement of the use of animals) objectives, is user-friendly and will accelerate development of new botulinum drugs. The sensitive enzymatic reporter cell line could also be adapted for the detection of toxin activity during the manufacture of botulinum and tetanus vaccines.
Collapse
Affiliation(s)
- Aleksander Rust
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Ciara Doran
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Rosalyn Hart
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Thomas Binz
- Institut für Zellbiochemie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Paul Stickings
- Division of Bacteriology, National Institute for Biological Standards and Control, Medicines and Healthcare Product Regulatory Agency, Potters Bar, United Kingdom
| | - Dorothea Sesardic
- Division of Bacteriology, National Institute for Biological Standards and Control, Medicines and Healthcare Product Regulatory Agency, Potters Bar, United Kingdom
| | - Andrew A. Peden
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| | - Bazbek Davletov
- Department of Biomedical Sciences, University of Sheffield, Sheffield, United Kingdom
| |
Collapse
|
15
|
Yadirgi G, Stickings P, Rajagopal S, Liu Y, Sesardic D. Immuno-detection of cleaved SNAP-25 from differentiated mouse embryonic stem cells provides a sensitive assay for determination of botulinum A toxin and antitoxin potency. J Immunol Methods 2017; 451:90-99. [PMID: 28943257 DOI: 10.1016/j.jim.2017.09.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 01/12/2023]
Abstract
Botulinum toxin type A is a causative agent of human botulism. Due to high toxicity and ease of production it is classified by the Centres for Disease Control and Prevention as a category A bioterrorism agent. The same serotype, BoNT/A, is also the most widely used in pharmaceutical preparations for treatment of a diverse range of neuromuscular disorders. Traditionally, animals are used to confirm the presence and activity of toxin and to establish neutralizing capabilities of countermeasures in toxin neutralization tests. Cell based assays for BoNT/A have been reported as the most viable alternative to animal models, since they are capable of reflecting all key steps (binding, translocation, internalization and cleavage of intracellular substrate) involved in toxin activity. In this paper we report preliminary development of a simple immunochemical method for specifically detecting BoNT/A cleaved intracellular substrate, SNAP-25, in cell lysates of neurons derived from mouse embryonic stem cells. The assay offers sensitivity of better than 0.1LD50/ml (3fM) which is not matched by other functional assays, including the mouse bioassay, and provides serotype specificity for quantitative detection of BoNT/A and anti-BoNT/A antitoxin. Subject to formal validation, the method described here could potentially be used as a substitute for the mouse bioassay to measure potency and consistency of therapeutic products.
Collapse
Affiliation(s)
- G Yadirgi
- Division of Bacteriology, National Institute for Biological Standards and Control, a center of the Medicines and Healthcare Products Regulatory Agency, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - P Stickings
- Division of Bacteriology, National Institute for Biological Standards and Control, a center of the Medicines and Healthcare Products Regulatory Agency, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - S Rajagopal
- Division of Bacteriology, National Institute for Biological Standards and Control, a center of the Medicines and Healthcare Products Regulatory Agency, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - Y Liu
- Division of Bacteriology, National Institute for Biological Standards and Control, a center of the Medicines and Healthcare Products Regulatory Agency, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - D Sesardic
- Division of Bacteriology, National Institute for Biological Standards and Control, a center of the Medicines and Healthcare Products Regulatory Agency, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| |
Collapse
|
16
|
SiMa Cells for a Serotype Specific and Sensitive Cell-Based Neutralization Test for Botulinum Toxin A and E. Toxins (Basel) 2017; 9:toxins9070230. [PMID: 28726719 PMCID: PMC5535177 DOI: 10.3390/toxins9070230] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/18/2017] [Indexed: 12/15/2022] Open
Abstract
Botulinum toxins (BoNTs), of which there are seven serotypes, are among the most potent neurotoxins, with serotypes A, B and E causing human botulism. Antitoxins form the first line of treatment for botulism, and functional, highly sensitive in vitro methods for toxin neutralization are needed to replace the current in vivo methods used for determination of antitoxin potency. In this preliminary proof of concept study, we report the development of a neutralization test using the neuroblastoma SiMa cell line. The assay is serotype specific for either BoNT/A or BoNT/E, which both cleave unique sequences on SNAP-25 within SiMa cells. The end point is simple immunodetection of cleaved SNAP-25 from cell lysates with antibodies detecting only the newly exposed sequence on SNAP-25. Neutralizing antibodies prevent the toxin-induced cleavage of SNAP-25. The toxin neutralization assay, with an EC50 of ~2 mIU/mL determined with a standardized reference antiserum, is more sensitive than the mouse bioassays. Relevance was demonstrated with commercial and experimental antitoxins targeting different functional domains, and of known in vivo neutralizing activities. This is the first report describing a simple, specific, in vitro cell-based assay for the detection of neutralizing antibodies against BoNT/A and BoNT/E with a sensitivity exceeding that of the mouse bioassay.
Collapse
|
17
|
Pellett S, Tepp WH, Johnson EA, Sesardic D. Assessment of ELISA as endpoint in neuronal cell-based assay for BoNT detection using hiPSC derived neurons. J Pharmacol Toxicol Methods 2017; 88:1-6. [PMID: 28465161 DOI: 10.1016/j.vascn.2017.04.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/25/2017] [Accepted: 04/28/2017] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Botulinum neurotoxins (BoNTs), the causative agents of botulism, are widely used as powerful bio-pharmaceuticals to treat neuro-muscular disorders. Due to the high potency and potential lethality of BoNTs, careful monitoring of the biologic activity of BoNT-based pharmaceuticals is required to ensure safe usage. For decades, the only approved method for potency determination of pharmaceutical BoNTs was the mouse bioassay (MBA), but in recent years improvements in cell-assay technologies have enabled MBA replacement by cell-based assays for specific product evaluations. This project details a method for quantitative and sensitive detection of biologic activity of BoNT/A1 in human induced pluripotent stem cell (hiPSC) derived neurons using an ELISA as a method to determine SNAP-25 cleavage by BoNT/A1 following toxin exposure. METHODS HiPSC derived neurons from two different sources were exposed to serial dilutions of BoNT/A1, and quantitative detection of toxin activity was evaluated and optimized in cell lysates using ELISA to detect cleaved SNAP-25. RESULTS The results from this study indicate that an ELISA using ultra TMB as a substrate quantitatively detects cleaved SNAP-25 in cell lysates of BoNT/A1 exposed hiPSC-derived neuronal cells with similar or greater sensitivity as Western blot (EC50~0.3U/well). DISCUSSION This study demonstrates a human specific and sensitive cell-based detection platform of BoNT/A1 activity using ELISA as an endpoint for quantitative detection of the SNAP-25 cleavage product. This assay is applicable to moderate to high-throughput formats and importantly employs non-cancerous human-specific neuronal cells for potency evaluation of a bio-pharmaceutical for human use.
Collapse
Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, United States.
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, United States.
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, 1550 Linden Dr., Madison, WI 53706, United States.
| | - Dorothea Sesardic
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), A centre of Medicines and Healthcare products Regulatory Agency; Hertfordshire EN6 3QG, UK.
| |
Collapse
|
18
|
Jenkinson SP, Grandgirard D, Heidemann M, Tscherter A, Avondet MA, Leib SL. Embryonic Stem Cell-Derived Neurons Grown on Multi-Electrode Arrays as a Novel In vitro Bioassay for the Detection of Clostridium botulinum Neurotoxins. Front Pharmacol 2017; 8:73. [PMID: 28280466 PMCID: PMC5322221 DOI: 10.3389/fphar.2017.00073] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/06/2017] [Indexed: 12/01/2022] Open
Abstract
Clostridium botulinum neurotoxins (BoNTs) are the most poisonous naturally occurring protein toxins known to mankind and are the causative agents of the severe and potentially life-threatening disease botulism. They are also known for their application as cosmetics and as unique bio-pharmaceuticals to treat an increasing number of neurological and non-neurological disorders. Currently, the potency of biologically active BoNT for therapeutic use is mainly monitored by the murine LD50-assay, an ethically disputable test causing suffering and death of a considerable number of mice. The aim of this study was to establish an in vitro assay as an alternative to the widely used in vivo mouse bioassay. We report a novel BoNT detection assay using mouse embryonic stem cell-derived neurons (mESN) cultured on multi-electrode arrays (MEAs). After 21 days in culture, the mESN formed a neuronal network showing spontaneous bursting activity based on functional synapses and express the necessary target proteins for BoNTs. Treating cultures for 6 h with 16.6 pM of BoNT serotype A and incubation with 1.66 pM BoNT/A or 33 Units/ml of Botox® for 24 h lead to a significant reduction of both spontaneous network bursts and average spike rate. This data suggests that mESN cultured on MEAs pose a novel, biologically relevant model that can be used to detect and quantify functional BoNT effects, thus accelerating BoNT research while decreasing animal use.
Collapse
Affiliation(s)
- Stephen P Jenkinson
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Biology Division, Spiez Laboratory, Swiss Federal Office for Civil ProtectionSpiez, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland; Graduate School for Cellular and Biomedical Sciences, University of BernBern, Switzerland
| | - Denis Grandgirard
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland
| | | | - Anne Tscherter
- Department of Physiology, University of Bern Bern, Switzerland
| | - Marc-André Avondet
- Biology Division, Spiez Laboratory, Swiss Federal Office for Civil Protection Spiez, Switzerland
| | - Stephen L Leib
- Neuroinfection Laboratory, Institute for Infectious Diseases, University of BernBern, Switzerland; Cluster for Regenerative Neuroscience, Department for Clinical Research, University of BernBern, Switzerland
| |
Collapse
|
19
|
Vazquez-Cintron EJ, Beske PH, Tenezaca L, Tran BQ, Oyler JM, Glotfelty EJ, Angeles CA, Syngkon A, Mukherjee J, Kalb SR, Band PA, McNutt PM, Shoemaker CB, Ichtchenko K. Engineering Botulinum Neurotoxin C1 as a Molecular Vehicle for Intra-Neuronal Drug Delivery. Sci Rep 2017; 7:42923. [PMID: 28220863 PMCID: PMC5318933 DOI: 10.1038/srep42923] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/16/2017] [Indexed: 12/21/2022] Open
Abstract
Botulinum neurotoxin (BoNT) binds to and internalizes its light chain into presynaptic compartments with exquisite specificity. While the native toxin is extremely lethal, bioengineering of BoNT has the potential to eliminate toxicity without disrupting neuron-specific targeting, thereby creating a molecular vehicle capable of delivering therapeutic cargo into the neuronal cytosol. Building upon previous work, we have developed an atoxic derivative (ad) of BoNT/C1 through rationally designed amino acid substitutions in the metalloprotease domain of wild type (wt) BoNT/C1. To test if BoNT/C1 ad retains neuron-specific targeting without concomitant toxic host responses, we evaluated the localization, activity, and toxicity of BoNT/C1 ad in vitro and in vivo. In neuronal cultures, BoNT/C1 ad light chain is rapidly internalized into presynaptic compartments, but does not cleave SNARE proteins nor impair spontaneous neurotransmitter release. In mice, systemic administration resulted in the specific co-localization of BoNT/C1 ad with diaphragmatic motor nerve terminals. The mouse LD50 of BoNT/C1 ad is 5 mg/kg, with transient neurological symptoms emerging at sub-lethal doses. Given the low toxicity and highly specific neuron-targeting properties of BoNT/C1 ad, these data suggest that BoNT/C1 ad can be useful as a molecular vehicle for drug delivery to the neuronal cytoplasm.
Collapse
Affiliation(s)
- Edwin J Vazquez-Cintron
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA.,The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Phillip H Beske
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Luis Tenezaca
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA
| | - Bao Q Tran
- Excet, Inc., 6225 Brandon Ave., Suite 360, Springfield, VA, 22150, USA
| | - Jonathan M Oyler
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Elliot J Glotfelty
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Christopher A Angeles
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Aurelia Syngkon
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| | - Jean Mukherjee
- Department of Infectious Diseases and Global Health, Tufts University Clinical and Translational Science Institute, North Grafton, MA, 01536, USA
| | - Suzanne R Kalb
- Centers for Disease Control and Prevention, National Center for Environmental Health/Agency for Toxic Substances and Disease Registry, Atlanta, GA 30341, USA
| | - Philip A Band
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA.,CytoDel LLC, New York, NY, 10027, USA.,Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, NY, 10016, USA
| | - Patrick M McNutt
- The United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Tufts University Clinical and Translational Science Institute, North Grafton, MA, 01536, USA
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, 10016, USA
| |
Collapse
|
20
|
Weingart OG, Loessner MJ. Nerve cell-mimicking liposomes as biosensor for botulinum neurotoxin complete physiological activity. Toxicol Appl Pharmacol 2016; 313:16-23. [PMID: 27743862 DOI: 10.1016/j.taap.2016.10.010] [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] [Received: 07/02/2016] [Revised: 09/02/2016] [Accepted: 10/10/2016] [Indexed: 10/20/2022]
Abstract
Botulinum neurotoxins (BoNT) are the most toxic substances known, and their neurotoxic properties and paralysing effects are exploited for medical treatment of a wide spectrum of disorders. To accurately quantify the potency of a pharmaceutical BoNT preparation, its physiological key activities (binding to membrane receptor, translocation, and proteolytic degradation of SNARE proteins) need to be determined. To date, this was only possible using animal models, or, to a limited extent, cell-based assays. We here report a novel in vitro system for BoNT/B analysis, based on nerve-cell mimicking liposomes presenting motoneuronal membrane receptors required for BoNT binding. Following triggered membrane translocation of the toxin's Light Chain, the endopeptidase activity can be quantitatively monitored employing a FRET-based reporter assay within the functionalized liposomes. We were able to detect BoNT/B physiological activity at picomolar concentrations in short time, opening the possibility for future replacement of animal experimentation in pharmaceutical BoNT testing.
Collapse
Affiliation(s)
- Oliver G Weingart
- Institute for Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, CH-8092 Zurich, Switzerland.
| | - Martin J Loessner
- Institute for Food, Nutrition and Health, ETH Zurich, Schmelzbergstrasse 7, CH-8092 Zurich, Switzerland
| |
Collapse
|
21
|
Wild E, Bonifas U, Klimek J, Trösemeier JH, Krämer B, Kegel B, Behrensdorf-Nicol HA. In vitro potency determination of botulinum neurotoxin B based on its receptor-binding and proteolytic characteristics. Toxicol In Vitro 2016; 34:97-104. [PMID: 27032463 DOI: 10.1016/j.tiv.2016.03.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2016] [Indexed: 01/09/2023]
Abstract
Botulinum neurotoxins (BoNTs) are the most potent toxins known. However, the paralytic effect caused by BoNT serotypes A and B is taken advantage of to treat different forms of dystonia and in cosmetic procedures. Due to the increasing areas of application, the demand for BoNTs A and B is rising steadily. Because of the high toxicity, it is mandatory to precisely determine the potency of every produced BoNT batch, which is usually accomplished by performing toxicity testing (LD50 test) in mice. Here we describe an alternative in vitro assay for the potency determination of the BoNT serotype B. In this assay, the toxin is first bound to its specific receptor molecules. After the proteolytic subunit of the toxin has been released and activated by chemical reduction, it is exposed to synaptobrevin, its substrate protein. Finally the proteolytic cleavage is quantified by an antibody-mediated detection of the neoepitope, reaching a detection limit below 0.1mouseLD50/ml. Thus, the assay, named BoNT/B binding and cleavage assay (BoNT/B BINACLE), takes into account the binding as well as the protease function of the toxin, thereby measuring its biological activity.
Collapse
Affiliation(s)
- Emina Wild
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany
| | - Ursula Bonifas
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany
| | - Jolanta Klimek
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany
| | - Jan-Hendrik Trösemeier
- Microbiology Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany; Molecular Bioinformatics, Institute of Computer Science, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
| | - Beate Krämer
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany
| | - Birgit Kegel
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany
| | - Heike A Behrensdorf-Nicol
- Veterinary Medicine Division, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicals), Langen, Germany.
| |
Collapse
|
22
|
Erickson BP, Lee WW, Cohen J, Grunebaum LD. The role of neurotoxins in the periorbital and midfacial areas. Facial Plast Surg Clin North Am 2016; 23:243-55. [PMID: 25921574 DOI: 10.1016/j.fsc.2015.01.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Initially popularized for the treatment of strabismus and blepharospasm, injection of botulinum neurotoxin has become the most commonly performed cosmetic treatment in the United States. Injection techniques have been particularly well-studied in the midface and periocular region, and patient satisfaction tends to be very high. We review the salient differences among available neurotoxins, how to optimally reconstitute them, how to inject the forehead, glabella, lateral canthal lines ("crow's feet"), infralid region, and transverse nasal lines ("bunny lines"), how to sculpt the brow, and how to manage potential complications.
Collapse
Affiliation(s)
- Benjamin P Erickson
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17th Street, Miami, FL 33136, USA
| | - Wendy W Lee
- Department of Clinical Ophthalmology and Dermatology Oculofacial Plastic & Reconstructive Surgery, Orbit and Oncology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 900 NW 17th Street, Miami, FL 33136, USA
| | - Joel Cohen
- AboutSkin Dermatology, 499 East Hamden Avenue, Suite 450, Englewood, CO 80113, USA
| | - Lisa D Grunebaum
- Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology and Dermatology, University of Miami Miller School of Medicine, 900 NW 17th Street, Miami, FL 33136, USA.
| |
Collapse
|
23
|
Abstract
Botulinum neurotoxin injections are a valuable treatment modality for many therapeutic indications and have revolutionized the field of aesthetic medicine so that they are the leading cosmetic procedure performed worldwide. Studies show that onabotulinumtoxinA, abobotulinumtoxinA, and incobotulinumtoxinA are comparable in terms of clinical efficacy. Differences between the products relate to the botulinum neurotoxin complexes, specific biological potency, and their immunogenicity. Protein complex size and molecular weight have no effect on biological activity, stability, distribution, or side effect profile. Complexing proteins and inactive toxin (toxoid) content increase the risk of neutralizing antibody formation, which can cause secondary treatment failure, particularly in chronic disorders that require frequent injections and long-term treatment. These attributes could lead to differences in therapeutic outcomes, and, given the widespread aesthetic use of these three neurotoxin products, physicians should be aware of how they differ to ensure their safe and effective use.
Collapse
Affiliation(s)
- Jürgen Frevert
- Head of Botulinum Toxin Research, Merz Pharmaceuticals GmbH, Hermannswerder 15, 14473, Potsdam, Germany,
| |
Collapse
|
24
|
Weisemann J, Krez N, Fiebig U, Worbs S, Skiba M, Endermann T, Dorner MB, Bergström T, Muñoz A, Zegers I, Müller C, Jenkinson SP, Avondet MA, Delbrassinne L, Denayer S, Zeleny R, Schimmel H, Åstot C, Dorner BG, Rummel A. Generation and Characterization of Six Recombinant Botulinum Neurotoxins as Reference Material to Serve in an International Proficiency Test. Toxins (Basel) 2015; 7:5035-54. [PMID: 26703728 PMCID: PMC4690111 DOI: 10.3390/toxins7124861] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 12/22/2022] Open
Abstract
The detection and identification of botulinum neurotoxins (BoNT) is complex due to the existence of seven serotypes, derived mosaic toxins and more than 40 subtypes. Expert laboratories currently use different technical approaches to detect, identify and quantify BoNT, but due to the lack of (certified) reference materials, analytical results can hardly be compared. In this study, the six BoNT/A1–F1 prototypes were successfully produced by recombinant techniques, facilitating handling, as well as improving purity, yield, reproducibility and biosafety. All six BoNTs were quantitatively nicked into active di-chain toxins linked by a disulfide bridge. The materials were thoroughly characterized with respect to purity, identity, protein concentration, catalytic and biological activities. For BoNT/A1, B1 and E1, serotypes pathogenic to humans, the catalytic activity and the precise protein concentration were determined by Endopep-mass spectrometry and validated amino acid analysis, respectively. In addition, BoNT/A1, B1, E1 and F1 were successfully detected by immunological assays, unambiguously identified by mass spectrometric-based methods, and their specific activities were assigned by the mouse LD50 bioassay. The potencies of all six BoNT/A1–F1 were quantified by the ex vivo mouse phrenic nerve hemidiaphragm assay, allowing a direct comparison. In conclusion, highly pure recombinant BoNT reference materials were produced, thoroughly characterized and employed as spiking material in a worldwide BoNT proficiency test organized by the EQuATox consortium.
Collapse
Affiliation(s)
| | - Nadja Krez
- Toxogen GmbH, Feodor-Lynen-Str. 35, 30625 Hannover, Germany.
| | - Uwe Fiebig
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin Skiba
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Tanja Endermann
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Martin B Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Tomas Bergström
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Cementvägen 20, 90182 Umeå, Sweden.
| | - Amalia Muñoz
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Ingrid Zegers
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Christian Müller
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Stephen P Jenkinson
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Marc-Andre Avondet
- Federal Department of Defence, Civil Protection and Sport-Spiez Laboratory, Austrasse 1, 3700 Spiez, Switzerland.
| | - Laurence Delbrassinne
- Scientific Service of Food-Borne Pathogens, Operational Directorate of Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Sarah Denayer
- Scientific Service of Food-Borne Pathogens, Operational Directorate of Communicable and Infectious Diseases, Scientific Institute of Public Health (WIV-ISP), 1050 Brussels, Belgium.
| | - Reinhard Zeleny
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Heinz Schimmel
- Joint Research Centre, Institute for Reference Materials and Measurements, European Commission, Retieseweg 111, 2440 Geel, Belgium.
| | - Crister Åstot
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Cementvägen 20, 90182 Umeå, Sweden.
| | - Brigitte G Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestr. 10, 13353 Berlin, Germany.
| | - Andreas Rummel
- Toxogen GmbH, Feodor-Lynen-Str. 35, 30625 Hannover, Germany.
| |
Collapse
|
25
|
Simon S, Fiebig U, Liu Y, Tierney R, Dano J, Worbs S, Endermann T, Nevers MC, Volland H, Sesardic D, Dorner MB. Recommended Immunological Strategies to Screen for Botulinum Neurotoxin-Containing Samples. Toxins (Basel) 2015; 7:5011-34. [PMID: 26703727 PMCID: PMC4690110 DOI: 10.3390/toxins7124860] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 12/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) cause the life-threatening neurological illness botulism in humans and animals and are divided into seven serotypes (BoNT/A–G), of which serotypes A, B, E, and F cause the disease in humans. BoNTs are classified as “category A” bioterrorism threat agents and are relevant in the context of the Biological Weapons Convention. An international proficiency test (PT) was conducted to evaluate detection, quantification and discrimination capabilities of 23 expert laboratories from the health, food and security areas. Here we describe three immunological strategies that proved to be successful for the detection and quantification of BoNT/A, B, and E considering the restricted sample volume (1 mL) distributed. To analyze the samples qualitatively and quantitatively, the first strategy was based on sensitive immunoenzymatic and immunochromatographic assays for fast qualitative and quantitative analyses. In the second approach, a bead-based suspension array was used for screening followed by conventional ELISA for quantification. In the third approach, an ELISA plate format assay was used for serotype specific immunodetection of BoNT-cleaved substrates, detecting the activity of the light chain, rather than the toxin protein. The results provide guidance for further steps in quality assurance and highlight problems to address in the future.
Collapse
Affiliation(s)
- Stéphanie Simon
- CEA Saclay, Institute of Biology and Technologies of Saclay, Laboratory for Immunoanalytical Researches, Gif-sur-Yvette 91191 cedex, France.
| | - Uwe Fiebig
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| | - Yvonne Liu
- Division of Bacteriology, National Institute for Biological Standards and Control, a Centre of Medicines & Healthcare Products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - Rob Tierney
- Division of Bacteriology, National Institute for Biological Standards and Control, a Centre of Medicines & Healthcare Products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - Julie Dano
- CEA Saclay, Institute of Biology and Technologies of Saclay, Laboratory for Immunoanalytical Researches, Gif-sur-Yvette 91191 cedex, France.
| | - Sylvia Worbs
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| | - Tanja Endermann
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| | - Marie-Claire Nevers
- CEA Saclay, Institute of Biology and Technologies of Saclay, Laboratory for Immunoanalytical Researches, Gif-sur-Yvette 91191 cedex, France.
| | - Hervé Volland
- CEA Saclay, Institute of Biology and Technologies of Saclay, Laboratory for Immunoanalytical Researches, Gif-sur-Yvette 91191 cedex, France.
| | - Dorothea Sesardic
- Division of Bacteriology, National Institute for Biological Standards and Control, a Centre of Medicines & Healthcare Products Regulatory Agency, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK.
| | - Martin B Dorner
- Biological Toxins, Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Seestrasse 10, 13353 Berlin, Germany.
| |
Collapse
|
26
|
Botulinum Neurotoxins: Qualitative and Quantitative Analysis Using the Mouse Phrenic Nerve Hemidiaphragm Assay (MPN). Toxins (Basel) 2015; 7:4895-905. [PMID: 26610569 PMCID: PMC4690105 DOI: 10.3390/toxins7124855] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 08/26/2015] [Accepted: 09/01/2015] [Indexed: 12/30/2022] Open
Abstract
The historical method for the detection of botulinum neurotoxin (BoNT) is represented by the mouse bioassay (MBA) measuring the animal survival rate. Since the endpoint of the MBA is the death of the mice due to paralysis of the respiratory muscle, an ex vivo animal replacement method, called mouse phrenic nerve (MPN) assay, employs the isolated N. phrenicus-hemidiaphragm tissue. Here, BoNT causes a dose-dependent characteristic decrease of the contraction amplitude of the indirectly stimulated muscle. Within the EQuATox BoNT proficiency 13 test samples were analysed using the MPN assay by serial dilution to a bath concentration resulting in a paralysis time within the range of calibration curves generated with BoNT/A, B and E standards, respectively. For serotype identification the diluted samples were pre-incubated with polyclonal anti-BoNT/A, B or E antitoxin or a combination of each. All 13 samples were qualitatively correctly identified thereby delivering superior results compared to single in vitro methods like LFA, ELISA and LC-MS/MS. Having characterized the BoNT serotype, the final bath concentrations were calculated using the calibration curves and then multiplied by the respective dilution factor to obtain the sample concentration. Depending on the source of the BoNT standards used, the quantitation of ten BoNT/A containing samples delivered a mean z-score of 7 and of three BoNT/B or BoNT/E containing samples z-scores <2, respectively.
Collapse
|
27
|
Eckle VS, Balk M, Thiermann H, Antkowiak B, Grasshoff C. Botulinum toxin B increases intrinsic muscle activity in organotypic spinal cord-skeletal muscle co-cultures. Toxicol Lett 2015; 244:167-171. [PMID: 26260118 DOI: 10.1016/j.toxlet.2015.08.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 07/30/2015] [Accepted: 08/04/2015] [Indexed: 12/21/2022]
Abstract
In organotypic spinal cord-skeletal muscle co-cultures, motoneurons are driven by locomotor commands and induce contractions in surrounding muscle fibres. Using these co-cultures, it has been shown that effects of organophosphorus compounds on neuromuscular synapses can be determined in vitro. In the present study we aimed to extend this in vitro tool for pharmacologic testing of botulinum toxin B. This neurotoxin is widely used for the treatment of dystonia. Besides its effects on the neuromuscular junction, botulinum toxins may also act at centrally located synapses. Incubation with botulinum toxin B (Neurobloc(®)) induced a significant increase in muscular activity after 24, 48 and 72h. Application of the NMDA- and AMPA-receptor antagonists AP5 (20μM) and CNQX (15μM) induced a similar augmentation of muscle activity after 48 and 72h, respectively. Administration of the glycine- and GABA(A)-receptor antagonists strychnine (1μM) and bicuculline (100μM) did not alter intrinsic muscle activity. In contrast, application of a non-depolarizing muscle relaxant rocuronium bromide reduced the muscle activity in a dose-dependent manner. Our findings suggest that glutamatergic synapses in the spinal cord are more sensitive to botulinum toxin B than synaptic contacts between spinal motoneurons and muscle fibres.
Collapse
Affiliation(s)
- Veit-Simon Eckle
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care Medicine, Eberhard-Karls-University, Tübingen, Germany.
| | - Monika Balk
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care Medicine, Eberhard-Karls-University, Tübingen, Germany
| | - Horst Thiermann
- Bundeswehr Institute of Pharmacology and Toxicology, Munich, Germany
| | - Bernd Antkowiak
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care Medicine, Eberhard-Karls-University, Tübingen, Germany
| | - Christian Grasshoff
- Experimental Anesthesiology Section, Department of Anesthesiology and Intensive Care Medicine, Eberhard-Karls-University, Tübingen, Germany
| |
Collapse
|
28
|
A chip-based assay for botulinum neurotoxin A activity in pharmaceutical preparations. Appl Microbiol Biotechnol 2015; 99:4355-60. [PMID: 25672850 DOI: 10.1007/s00253-015-6438-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 01/25/2015] [Indexed: 12/30/2022]
Abstract
The production of botulinum neurotoxin A (BoNT/A) for therapeutic and cosmetic applications requires precise determination of batch potency, and the enzymatic activity of BoNT/A light chain is a crucial index that can be measured in vitro. We previously established a SNAP-25 chip-based assay using surface plasmon resonance (SPR) that is more sensitive than the standard mouse bioassay for the quantification of BoNT/A activity. We have now adapted this procedure for pharmaceutical preparations. The optimized SPR assay allowed multiple measurements on a single chip, including the kinetics of substrate cleavage. The activity of five different batches of a pharmaceutical BoNT/A preparation was determined in a blind study by SPR and found to be in agreement with data from the in vivo mouse lethality assay. Biosensor detection of specific proteolytic products has the potential to accurately monitor the activity of pharmaceutical BoNT/A preparations, and a single chip can be used to assay more than 100 samples.
Collapse
|
29
|
Torii Y, Goto Y, Nakahira S, Ginnaga A. Establishment of alternative potency test for botulinum toxin type A using compound muscle action potential (CMAP) in rats. Toxicon 2014; 90:97-105. [PMID: 25110177 DOI: 10.1016/j.toxicon.2014.07.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/24/2014] [Accepted: 07/24/2014] [Indexed: 12/27/2022]
Abstract
The biological activity of botulinum toxin type A has been evaluated using the mouse intraperitoneal (ip) LD50 test. This method requires a large number of mice to precisely determine toxin activity, and, as such, poses problems with regard to animal welfare. We previously developed a compound muscle action potential (CMAP) assay using rats as an alternative method to the mouse ip LD50 test. In this study, to evaluate this quantitative method of measuring toxin activity using CMAP, we assessed the parameters necessary for quantitative tests according to ICH Q2 (R1). This assay could be used to evaluate the activity of the toxin, even when inactive toxin was mixed with the sample. To reduce the number of animals needed, this assay was set to measure two samples per animal. Linearity was detected over a range of 0.1-12.8 U/mL, and the measurement range was set at 0.4-6.4 U/mL. The results for accuracy and precision showed low variability. The body weight was selected as a variable factor, but it showed no effect on the CMAP amplitude. In this study, potency tests using the rat CMAP assay of botulinum toxin type A demonstrated that it met the criteria for a quantitative analysis method.
Collapse
Affiliation(s)
- Yasushi Torii
- The Chemo-Sero- Therapeutic Research Institute (KAKETSUKEN), 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan; Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita-shi, Osaka 565-0871, Japan.
| | - Yoshitaka Goto
- The Chemo-Sero- Therapeutic Research Institute (KAKETSUKEN), 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan
| | - Shinji Nakahira
- The Chemo-Sero- Therapeutic Research Institute (KAKETSUKEN), 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan
| | - Akihiro Ginnaga
- The Chemo-Sero- Therapeutic Research Institute (KAKETSUKEN), 1-6-1 Okubo, Kita-ku, Kumamoto-shi, Kumamoto 860-8568, Japan
| |
Collapse
|
30
|
Development of a prediction method for skin sensitization using novel cysteine and lysine derivatives. J Pharmacol Toxicol Methods 2014; 70:94-105. [DOI: 10.1016/j.vascn.2014.06.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/08/2014] [Accepted: 06/02/2014] [Indexed: 12/29/2022]
|
31
|
Peiser M, Hitzler M, Luch A. On the role of co-inhibitory molecules in dendritic cell: T helper cell coculture assays aimed to detect chemical-induced contact allergy. EXPERIENTIA SUPPLEMENTUM (2012) 2014; 104:115-35. [PMID: 24214622 DOI: 10.1007/978-3-0348-0726-5_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
T cells play a pivotal role in sensitization and elicitation of type IV allergic reactions. While T helper cells sustain and maintain the differentiation of further effector cells, regulatory T cells are involved in control of cytokine release and proliferation, and T killer cells execute cellular lysis, thereby leading to certain levels of tissue damage. According to their central role, the widely applied and OECD-supported test method for the assessment of the sensitization potential of a chemical, i.e., the local lymph node assay (LLNA), relies on the detection of the immune-responsive proliferation of lymphocytes. However, most sensitization assays recently developed take advantage of the initiators of sensitization, dendritic cells (DCs) or DC-like cell lines. Here, we focus on inhibitory molecules expressed on the surface of DCs and their corresponding receptors on T cells. We summarize insight into the function of CTLA-4, the ligands of inducible co-stimulators (ICOSs), and on the inhibitory receptor programmed death (PD). The targeting of immune cell surface receptors by inhibitory molecules holds some promise with regard to the development of T cell-based sensitization assays. Firstly, a broader and more sensitive dynamic range of detection could be achieved by blocking inhibitors or by removing inhibiting regulatory T cells from the assays. Secondly, the actual expression levels of inhibitory molecules could be also a valuable indicator for the process of sensitization. Finally, inhibitory molecules in coculture test systems are supposed to have a major influence on DCs by reverse signaling, thereby affecting their differentiation and maturation status in a feedback loop. In conclusion, inhibitory ligands of DC surface receptors and/or their cognate receptors on T cells could serve as useful tools in cell-based assays, directly influencing toxicological endpoints such as sensitization.
Collapse
Affiliation(s)
- Matthias Peiser
- Department of Product Safety, German Federal Institute for Risk Assessment (BfR), Max-Dohrn-Strasse 8-10, 10589, Berlin, Germany,
| | | | | |
Collapse
|
32
|
Kiris E, Kota KP, Burnett JC, Soloveva V, Kane CD, Bavari S. Recent developments in cell-based assays and stem cell technologies for botulinum neurotoxin research and drug discovery. Expert Rev Mol Diagn 2014; 14:153-68. [PMID: 24450833 DOI: 10.1586/14737159.2014.867808] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Botulinum neurotoxins (BoNTs) are exceptionally potent inhibitors of neurotransmission, causing muscle paralysis and respiratory failure associated with the disease botulism. Currently, no drugs are available to counter intracellular BoNT poisoning. To develop effective medical treatments, cell-based assays provide a valuable system to identify novel inhibitors in a time- and cost-efficient manner. Consequently, cell-based systems including immortalized cells, primary neurons and stem cell-derived neurons have been established. Stem cell-derived neurons are highly sensitive to BoNT intoxication and represent an ideal model to study the biological effects of BoNTs. Robust immunoassays are used to quantify BoNT activity and play a central role during inhibitor screening. In this review, we examine recent progress in physiologically relevant cell-based assays and high-throughput screening approaches for the identification of both direct and indirect BoNT inhibitors.
Collapse
Affiliation(s)
- Erkan Kiris
- Geneva Foundation, 917 Pacific Avenue, Tacoma, WA 98402, USA
| | | | | | | | | | | |
Collapse
|
33
|
Pellett S. Progress in cell based assays for botulinum neurotoxin detection. Curr Top Microbiol Immunol 2013; 364:257-85. [PMID: 23239357 DOI: 10.1007/978-3-642-33570-9_12] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Botulinum neurotoxins (BoNTs) are the most potent human toxins known and the causative agent of botulism, and are widely used as valuable pharmaceuticals. The BoNTs are modular proteins consisting of a heavy chain and a light chain linked by a disulfide bond. Intoxication of neuronal cells by BoNTs is a multi-step process including specific cell binding, endocytosis, conformational change in the endosome, translocation of the enzymatic light chain into the cells cytosol, and SNARE target cleavage. The quantitative and reliable potency determination of fully functional BoNTs produced as active pharmaceutical ingredient (API) requires an assay that considers all steps in the intoxication pathway. The in vivo mouse bioassay has for years been the 'gold standard' assay used for this purpose, but it requires the use of large numbers of mice and thus causes associated costs and ethical concerns. Cell-based assays are currently the only in vitro alternative that detect fully functional BoNTs in a single assay and have been utilized for years for research purposes. Within the last 5 years, several cell-based BoNT detection assays have been developed that are able to quantitatively determine BoNT potency with similar or greater sensitivity than the mouse bioassay. These assays now offer an alternative method for BoNT potency determination. Such quantitative and reliable BoNT potency determination is a crucial step in basic research, in the development of pharmaceutical BoNTs, and in the quantitative detection of neutralizing antibodies.
Collapse
Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA.
| |
Collapse
|
34
|
Chen JJ, Dashtipour K. Abo-, inco-, ona-, and rima-botulinum toxins in clinical therapy: a primer. Pharmacotherapy 2013; 33:304-18. [PMID: 23400888 DOI: 10.1002/phar.1196] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Botulinum neurotoxin (BoNT) is an acetylcholine release inhibitor and a neuromuscular-blocking agent used for the treatment of a variety of medical and cosmetic indications. Currently, in the United States, there are four BoNT formulations licensed for use: abobotulinumtoxinA, incobotulinumtoxinA, onabotulinumtoxinA, and rimabotulinumtoxinB. These revised name designations were established to reinforce the understanding that each BoNT product has an individual potency and is not interchangeable with any other BoNT product. The therapeutic use of BoNTs is expanding and new formulations are on the horizon. This article is a primer that describes distinctions among currently available, licensed BoNT formulations. Toxin pharmacology, product characteristics, storage, handling, preparation, and dosages will be reviewed. In addition, issues related to dose equivalency ratios, immunogenicity, potency, and toxin spread will be discussed. Therapeutic indications and safety are discussed briefly. Knowledge of the available and licensed BoNT formulations and the ability to make distinctions in toxin pharmacology, product characteristics, and indications are vital for product selection, preparation, drug information, avoidance of drug errors, quality assurance, and patient safety.
Collapse
Affiliation(s)
- Jack J Chen
- School of Pharmacy, Shryock Hall #225, Loma Linda University, Loma Linda, CA 92350, USA.
| | | |
Collapse
|
35
|
Fernández-Salas E, Wang J, Molina Y, Nelson JB, Jacky BPS, Aoki KR. Botulinum neurotoxin serotype A specific cell-based potency assay to replace the mouse bioassay. PLoS One 2012. [PMID: 23185348 PMCID: PMC3504020 DOI: 10.1371/journal.pone.0049516] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Botulinum neurotoxin serotype A (BoNT/A), a potent therapeutic used to treat various disorders, inhibits vesicular neurotransmitter exocytosis by cleaving SNAP25. Development of cell-based potency assays (CBPAs) to assess the biological function of BoNT/A have been challenging because of its potency. CBPAs can evaluate the key steps of BoNT action: receptor binding, internalization-translocation, and catalytic activity; and therefore could replace the current mouse bioassay. Primary neurons possess appropriate sensitivity to develop potential replacement assays but those potency assays are difficult to perform and validate. This report describes a CBPA utilizing differentiated human neuroblastoma SiMa cells and a sandwich ELISA that measures BoNT/A-dependent intracellular increase of cleaved SNAP25. Assay sensitivity is similar to the mouse bioassay and measures neurotoxin biological activity in bulk drug substance and BOTOX® product (onabotulinumtoxinA). Validation of a version of this CBPA in a Quality Control laboratory has led to FDA, Health Canada, and European Union approval for potency testing of BOTOX®, BOTOX® Cosmetic, and Vistabel®. Moreover, we also developed and optimized a BoNT/A CBPA screening assay that can be used for the discovery of novel BoNT/A inhibitors to treat human disease.
Collapse
Affiliation(s)
- Ester Fernández-Salas
- Department of Biological Sciences, Allergan Inc., Irvine, California, United States of America.
| | | | | | | | | | | |
Collapse
|
36
|
Kim SH, Kim SB, Yang GH, Rhee CH. Mouse compound muscle action potential assay: An alternative method to conduct the LD50 botulinum toxin type A potency test. Toxicon 2012; 60:341-7. [DOI: 10.1016/j.toxicon.2012.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 05/03/2012] [Accepted: 05/08/2012] [Indexed: 12/01/2022]
|
37
|
Neurotransmitter vesicle release from human model neurons (NT2) is sensitive to botulinum toxin A. Cell Mol Neurobiol 2012; 32:1021-9. [PMID: 22373696 DOI: 10.1007/s10571-012-9818-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Accepted: 02/14/2012] [Indexed: 01/06/2023]
Abstract
Botulinum neurotoxins (BoNTs) internalize into nerve terminals and block the release of neurotransmitters into the synapse. BoNTs are widely used as a therapeutic agent for treatment of movement disorders and recently gained more attention as a biological weapon. Consequently, there is strong interest to develop a cell-based assay platform to screen the toxicity and bioactivity of the BoNTs. In this study, we present an in vitro screening assay for BoNT/A based on differentiated human embryonal carcinoma stem (NT2) cells. The human NT2 cells fully differentiated into mature neurons that display immunoreactivity to cytoskeletal markers (βIII-tubulin and MAP2) and presynaptic proteins (synapsin and synaptotagmin I). We showed that the human NT2 cells undergo a process of exo-endocytotic synaptic vesicle recycling upon depolarization with high K(+) buffer. By employing an antibody directed against light chain of BoNT/A, we detected internalized toxin as a punctate staining along the neurites of the NT2 neurons. Using well-established methods of synaptic vesicle exocytosis assay (luminal synaptotagmin I and FM1-43 imaging) we show that pre-incubation with BoNT/A resulted in a blockade of vesicle release from human NT2 neurons in a dose-dependent manner. Moreover, this blocking effect of BoNT/A was abolished by pre-adsorbing the toxin with neutralizing antibody. In a proof of principle, we demonstrate that our cell culture assay for vesicle release is sensitive to BoNT/A and the activity of BoNT/A can be blocked by specific neutralizing antibodies. Overall our data suggest that human NT2 neurons are suitable for large scale screening of botulinum bioactivity.
Collapse
|
38
|
|
39
|
Liebsch M, Grune B, Seiler A, Butzke D, Oelgeschläger M, Pirow R, Adler S, Riebeling C, Luch A. Alternatives to animal testing: current status and future perspectives. Arch Toxicol 2011; 85:841-58. [PMID: 21607681 PMCID: PMC3149673 DOI: 10.1007/s00204-011-0718-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
On the occasion of the 20th anniversary of the Center for Alternative Methods to Animal Experiments (ZEBET), an international symposium was held at the German Federal Institute for Risk Assessment (BfR) in Berlin. At the same time, this symposium was meant to celebrate the 50th anniversary of the publication of the book “The Principles of Humane Experimental Technique” by Russell and Burch in 1959 in which the 3Rs principle (that is, Replacement, Reduction, and Refinement) has been coined and introduced to foster the development of alternative methods to animal testing. Another topic addressed by the symposium was the new vision on “Toxicology in the twenty-first Century”, as proposed by the US-National Research Council, which aims at using human cells and tissues for toxicity testing in vitro rather than live animals. An overview of the achievements and current tasks, as well as a vision of the future to be addressed by ZEBET@BfR in the years to come is outlined in the present paper.
Collapse
Affiliation(s)
- Manfred Liebsch
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Barbara Grune
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Andrea Seiler
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Daniel Butzke
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Michael Oelgeschläger
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Ralph Pirow
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Sarah Adler
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Christian Riebeling
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| | - Andreas Luch
- German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments—ZEBET, 12277 Berlin, Germany
| |
Collapse
|
40
|
Adler S, Basketter D, Creton S, Pelkonen O, van Benthem J, Zuang V, Andersen KE, Angers-Loustau A, Aptula A, Bal-Price A, Benfenati E, Bernauer U, Bessems J, Bois FY, Boobis A, Brandon E, Bremer S, Broschard T, Casati S, Coecke S, Corvi R, Cronin M, Daston G, Dekant W, Felter S, Grignard E, Gundert-Remy U, Heinonen T, Kimber I, Kleinjans J, Komulainen H, Kreiling R, Kreysa J, Leite SB, Loizou G, Maxwell G, Mazzatorta P, Munn S, Pfuhler S, Phrakonkham P, Piersma A, Poth A, Prieto P, Repetto G, Rogiers V, Schoeters G, Schwarz M, Serafimova R, Tähti H, Testai E, van Delft J, van Loveren H, Vinken M, Worth A, Zaldivar JM. Alternative (non-animal) methods for cosmetics testing: current status and future prospects-2010. Arch Toxicol 2011; 85:367-485. [PMID: 21533817 DOI: 10.1007/s00204-011-0693-2] [Citation(s) in RCA: 357] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 03/03/2011] [Indexed: 01/09/2023]
Abstract
The 7th amendment to the EU Cosmetics Directive prohibits to put animal-tested cosmetics on the market in Europe after 2013. In that context, the European Commission invited stakeholder bodies (industry, non-governmental organisations, EU Member States, and the Commission's Scientific Committee on Consumer Safety) to identify scientific experts in five toxicological areas, i.e. toxicokinetics, repeated dose toxicity, carcinogenicity, skin sensitisation, and reproductive toxicity for which the Directive foresees that the 2013 deadline could be further extended in case alternative and validated methods would not be available in time. The selected experts were asked to analyse the status and prospects of alternative methods and to provide a scientifically sound estimate of the time necessary to achieve full replacement of animal testing. In summary, the experts confirmed that it will take at least another 7-9 years for the replacement of the current in vivo animal tests used for the safety assessment of cosmetic ingredients for skin sensitisation. However, the experts were also of the opinion that alternative methods may be able to give hazard information, i.e. to differentiate between sensitisers and non-sensitisers, ahead of 2017. This would, however, not provide the complete picture of what is a safe exposure because the relative potency of a sensitiser would not be known. For toxicokinetics, the timeframe was 5-7 years to develop the models still lacking to predict lung absorption and renal/biliary excretion, and even longer to integrate the methods to fully replace the animal toxicokinetic models. For the systemic toxicological endpoints of repeated dose toxicity, carcinogenicity and reproductive toxicity, the time horizon for full replacement could not be estimated.
Collapse
Affiliation(s)
- Sarah Adler
- Centre for Documentation and Evaluation of Alternatives to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|