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Brin MF, Nelson M, Ashourian N, Brideau-Andersen A, Maltman J. Update on Non-Interchangeability of Botulinum Neurotoxin Products. Toxins (Basel) 2024; 16:266. [PMID: 38922160 PMCID: PMC11209304 DOI: 10.3390/toxins16060266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/01/2024] [Accepted: 06/05/2024] [Indexed: 06/27/2024] Open
Abstract
The growing use of botulinum neurotoxins (BoNTs) for medical and aesthetic purposes has led to the development and marketing of an increasing number of BoNT products. Given that BoNTs are biological medications, their characteristics are heavily influenced by their manufacturing methods, leading to unique products with distinct clinical characteristics. The manufacturing and formulation processes for each BoNT are proprietary, including the potency determination of reference standards and other features of the assays used to measure unit potency. As a result of these differences, units of BoNT products are not interchangeable or convertible using dose ratios. The intrinsic, product-level differences among BoNTs are compounded by differences in the injected tissues, which are innervated by different nerve fiber types (e.g., motor, sensory, and/or autonomic nerves) and require unique dosing and injection sites that are particularly evident when treating complex therapeutic and aesthetic conditions. It is also difficult to compare across studies due to inherent differences in patient populations and trial methods, necessitating attention to study details underlying each outcome reported. Ultimately, each BoNT possesses a unique clinical profile for which unit doses and injection paradigms must be determined individually for each indication. This practice will help minimize unexpected adverse events and maximize efficacy, duration, and patient satisfaction. With this approach, BoNT is poised to continue as a unique tool for achieving individual goals for an increasing number of medical and aesthetic indications.
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Affiliation(s)
- Mitchell F. Brin
- AbbVie/Allergan Aesthetics, Irvine, CA 92612, USA; (A.B.-A.); (J.M.)
- Department of Neurology, University of California, Irvine, CA 92697, USA
| | | | | | | | - John Maltman
- AbbVie/Allergan Aesthetics, Irvine, CA 92612, USA; (A.B.-A.); (J.M.)
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Leka O, Wu Y, Zanetti G, Furler S, Reinberg T, Marinho J, Schaefer JV, Plückthun A, Li X, Pirazzini M, Kammerer RA. A DARPin promotes faster onset of botulinum neurotoxin A1 action. Nat Commun 2023; 14:8317. [PMID: 38110403 PMCID: PMC10728214 DOI: 10.1038/s41467-023-44102-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 11/30/2023] [Indexed: 12/20/2023] Open
Abstract
In this study, we characterize Designed Ankyrin Repeat Proteins (DARPins) as investigative tools to probe botulinum neurotoxin A1 (BoNT/A1) structure and function. We identify DARPin-F5 that completely blocks SNAP25 substrate cleavage by BoNT/A1 in vitro. X-ray crystallography reveals that DARPin-F5 inhibits BoNT/A1 activity by interacting with a substrate-binding region between the α- and β-exosite. This DARPin does not block substrate cleavage of BoNT/A3, indicating that DARPin-F5 is a subtype-specific inhibitor. BoNT/A1 Glu-171 plays a critical role in the interaction with DARPin-F5 and its mutation to Asp, the residue found in BoNT/A3, results in a loss of inhibition of substrate cleavage. In contrast to the in vitro results, DARPin-F5 promotes faster substrate cleavage of BoNT/A1 in primary neurons and muscle tissue by increasing toxin translocation. Our findings could have important implications for the application of BoNT/A1 in therapeutic areas requiring faster onset of toxin action combined with long persistence.
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Affiliation(s)
- Oneda Leka
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Yufan Wu
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Giulia Zanetti
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
| | - Sven Furler
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Thomas Reinberg
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Joana Marinho
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Jonas V Schaefer
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Xiaodan Li
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, 35121, Padova, Italy
| | - Richard A Kammerer
- Laboratory of Biomolecular Research, Division of Biology, Paul Scherrer Institut, 5232, Villigen PSI, Switzerland.
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Kwak S, Lee JY, Kim MJ, Lee HJ, Lee DK, Kang J, Kang WH, Son WC, Cruz DJM. Combination of PD-1 Checkpoint Blockade and Botulinum Toxin Type A1 Improves Antitumor Responses in Mouse Tumor Models of Melanoma and Colon Carcinoma. Immunol Invest 2023; 52:749-766. [PMID: 37403798 DOI: 10.1080/08820139.2023.2232403] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
BACKGROUND Tumor innervation has been shown to be utilized by some solid cancers to support tumor initiation, growth, progression, and metastasis, as well as confer resistance to immune checkpoint blockade through suppression of antitumor immunologic responses. Since botulinum neurotoxin type A1 (BoNT/A1) blocks neuronal cholinergic signaling, its potential use as an anticancer drug in combination with anti-PD-1 therapy was investigated in four different syngeneic mouse tumor models. METHODS Mice implanted with breast (4T1), lung (LLC1), colon (MC38), and melanoma (B16-F10) tumors were administered a single intratumoral injection of 15 U/kg BoNT/A1, repeated intraperitoneal injections of 5 mg/kg anti-PD-1 (RMP1-14), or both. RESULTS Compared to the single-agent treatments, anti-PD-1 and BoNT/A1 combination treatment elicited significant reduction in tumor growth among B16-F10 and MC38 tumor-bearing mice. The combination treatment also lowered serum exosome levels in these mice compared to the placebo control group. In the B16-F10 syngeneic mouse tumor model, anti-PD-1 + BoNT/A1 combination treatment lowered the proportion of MDSCs, negated the increased proportion of Treg cells, and elicited a higher number of tumor-infiltrating CD4+ and CD8+ T lymphocytes into the tumor microenvironment compared to anti-PD-1 treatment alone. CONCLUSION Our findings demonstrate the synergistic antitumor effects of BoNT/A1 and PD-1 checkpoint blockade in mouse tumor models of melanoma and colon carcinoma. These findings provide some evidence on the potential application of BoNT/A1 as an anticancer drug in combination with immune checkpoint blockade and should be further explored.
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Affiliation(s)
- Seongsung Kwak
- Pharmacology and Toxicology Department, Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Ji-Young Lee
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Min Ju Kim
- Pharmacology and Toxicology Department, Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
| | - Hyo Jin Lee
- Pharmacology and Toxicology Department, Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
| | - Dong-Kyu Lee
- Pharmacology and Toxicology Department, Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
| | - Jiyeon Kang
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Won-Ho Kang
- Medytox Korea Co. Ltd., Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
| | - Woo-Chan Son
- Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Deu John M Cruz
- Pharmacology and Toxicology Department, Medytox Gwanggyo R&D Center, Yeongtong-gu, Suwon-si, Republic of Korea
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Kaji R. A look at the future-new BoNTs and delivery systems in development: What it could mean in the clinic. Toxicon 2023; 234:107264. [PMID: 37657515 DOI: 10.1016/j.toxicon.2023.107264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/07/2023] [Accepted: 08/22/2023] [Indexed: 09/03/2023]
Abstract
Despite the expanding clinical utility of botulinum neurotoxins, there remain problems to be solved for attaining the best outcome. The efficacy and safety need to be reconsidered for commercially available preparations all derived from subtype A1 or B1. Emerging new toxins include A2 or A6 subtypes or engineered toxins with less spread, more potency, longer durations of action, less antigenicity and better safety profile than currently used preparations. Non-toxic BoNTs with a few amino acid replacements of the light chain (LC) may have a role as a drug-delivery system if the toxicity is abolished entirely. At present, efficacy of these BoNTs in animal botulism was demonstrated.
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Affiliation(s)
- Ryuji Kaji
- Tokushima University, Department of Clinical Neuroscience, 2-50-1 Kuramoto-cho, Tokushima, 770-8503, Japan.
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5
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Gupta S, Pellett S. Recent Developments in Vaccine Design: From Live Vaccines to Recombinant Toxin Vaccines. Toxins (Basel) 2023; 15:563. [PMID: 37755989 PMCID: PMC10536331 DOI: 10.3390/toxins15090563] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 09/28/2023] Open
Abstract
Vaccines are one of the most effective strategies to prevent pathogen-induced illness in humans. The earliest vaccines were based on live inoculations with low doses of live or related pathogens, which carried a relatively high risk of developing the disease they were meant to prevent. The introduction of attenuated and killed pathogens as vaccines dramatically reduced these risks; however, attenuated live vaccines still carry a risk of reversion to a pathogenic strain capable of causing disease. This risk is completely eliminated with recombinant protein or subunit vaccines, which are atoxic and non-infectious. However, these vaccines require adjuvants and often significant optimization to induce robust T-cell responses and long-lasting immune memory. Some pathogens produce protein toxins that cause or contribute to disease. To protect against the effects of such toxins, chemically inactivated toxoid vaccines have been found to be effective. Toxoid vaccines are successfully used today at a global scale to protect against tetanus and diphtheria. Recent developments for toxoid vaccines are investigating the possibilities of utilizing recombinant protein toxins mutated to eliminate biologic activity instead of chemically inactivated toxins. Finally, one of the most contemporary approaches toward vaccine design utilizes messenger RNA (mRNA) as a vaccine candidate. This approach was used globally to protect against coronavirus disease during the COVID-19 pandemic that began in 2019, due to its advantages of quick production and scale-up, and effectiveness in eliciting a neutralizing antibody response. Nonetheless, mRNA vaccines require specialized storage and transport conditions, posing challenges for low- and middle-income countries. Among multiple available technologies for vaccine design and formulation, which technology is most appropriate? This review focuses on the considerable developments that have been made in utilizing diverse vaccine technologies with a focus on vaccines targeting bacterial toxins. We describe how advancements in vaccine technology, combined with a deeper understanding of pathogen-host interactions, offer exciting and promising avenues for the development of new and improved vaccines.
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Affiliation(s)
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA;
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Tepp WH, Bradshaw M, Gardner AP, Kaufman RL, Barbieri JT, Pellett S. Botulinum Neurotoxin A4 Has a 1000-Fold Reduced Potency Due to Three Single Amino Acid Alterations in the Protein Receptor Binding Domain. Int J Mol Sci 2023; 24:5690. [PMID: 36982762 PMCID: PMC10055998 DOI: 10.3390/ijms24065690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/19/2023] Open
Abstract
Botulinum neurotoxin subtype A4 (BoNT/A4) is ~1000-fold less potent than BoNT/A1. This study addresses the basis for low BoNT/A4 potency. Utilizing BoNT/A1-A4 and BoNT/A4-A1 Light Chain-Heavy Chain (LC-HC) chimeras, HC-A4 was responsible for low BoNT/A4 potency. Earlier studies showed BoNT/A1-receptor binding domain (Hcc) bound a β-strand peptide (556-564) and glycan-N559 within Luminal Domain 4 (LD4) of SV2C, the BoNT/A protein receptor. Relative to BoNT/A1, the Hcc of BoNT/A4 possesses two amino acid variants (D1141 and N1142) within the β-peptide binding interface and one amino acid variant (R1292) located near the SV2C glycan-N559. Introduction of BoNT/A4 β-strand peptide variant (D1141 and N1142) into BoNT/A1 reduced toxin potency 30-fold, and additional introduction of the BoNT/A4 glycan-N559 variant (D1141, N1142, and R1292) further reduced toxin potency to approach BoNT/A4. While introduction of BoNT/A1 glycan-N559 variant (G1292) into BoNT/A4 did not alter toxin potency, additional introduction of BoNT/A1 β-strand peptide variants (G1141, S1142, and G1292) resulted in potency approaching BoNT/A1 potency. Thus, outcomes from these functional and modeling studies indicate that in rodent models, disruption of Hcc -SV2C β-peptide and -glycan-N559 interactions mediate low BoNT/A4 potency, while in human motor neurons, disruption of Hcc-SV2C β-peptide alone mediates low BoNT/A4 potency, which link to a species-specific variation at SV2C563.
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Affiliation(s)
- William H. Tepp
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Marite Bradshaw
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Alexander P. Gardner
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA (J.T.B.)
| | - Rebecca L. Kaufman
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
| | - Joseph T. Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI 53226, USA (J.T.B.)
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA
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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.
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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
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A Comprehensive Structural Analysis of Clostridium botulinum Neurotoxin A Cell-Binding Domain from Different Subtypes. Toxins (Basel) 2023; 15:toxins15020092. [PMID: 36828407 PMCID: PMC9966434 DOI: 10.3390/toxins15020092] [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: 12/01/2022] [Revised: 01/11/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) cause flaccid neuromuscular paralysis by cleaving one of the SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) complex proteins. BoNTs display high affinity and specificity for neuromuscular junctions, making them one of the most potent neurotoxins known to date. There are seven serologically distinct BoNTs (serotypes BoNT/A to BoNT/G) which can be further divided into subtypes (e.g., BoNT/A1, BoNT/A2…) based on small changes in their amino acid sequence. Of these, BoNT/A1 and BoNT/B1 have been utilised to treat various diseases associated with spasticity and hypersecretion. There are potentially many more BoNT variants with differing toxicological profiles that may display other therapeutic benefits. This review is focused on the structural analysis of the cell-binding domain from BoNT/A1 to BoNT/A6 subtypes (HC/A1 to HC/A6), including features such as a ganglioside binding site (GBS), a dynamic loop, a synaptic vesicle glycoprotein 2 (SV2) binding site, a possible Lys-Cys/Cys-Cys bridge, and a hinge motion between the HCN and HCC subdomains. Characterising structural features across subtypes provides a better understanding of how the cell-binding domain functions and may aid the development of novel therapeutics.
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Gardner AP, Barbieri JT, Pellett S. How Botulinum Neurotoxin Light Chain A1 Maintains Stable Association with the Intracellular Neuronal Plasma Membrane. Toxins (Basel) 2022; 14:toxins14120814. [PMID: 36548711 PMCID: PMC9783275 DOI: 10.3390/toxins14120814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022] Open
Abstract
Botulinum neurotoxin serotype A (BoNT/A) is the most potent protein toxin for humans and is utilized as a therapy for numerous neurologic diseases. BoNT/A comprises a catalytic Light Chain (LC/A) and a Heavy Chain (HC/A) and includes eight subtypes (BoNT/A1-/A8). Previously we showed BoNT/A potency positively correlated with stable localization on the intracellular plasma membrane and identified a low homology domain (amino acids 268-357) responsible for LC/A1 stable co-localization with SNAP-25 on the plasma membrane, while LC/A3 was present in the cytosol of Neuro2A cells. In the present study, steady-state- and live-imaging of a cytosolic LC/A3 derivative (LC/A3V) engineered to contain individual structural elements of the A1 LDH showed that a 59 amino acid region (275-334) termed the MLD was sufficient to direct LC/A3V from the cytosol to the plasma membrane co-localized with SNAP-25. Informatics and experimental validation of the MLD-predicted R1 region (an α-helix, residues 275-300) and R2 region (a loop, α-helix, loop, residues 302-334) both contribute independent steps to the stable co-localization of LC/A1 with SNAP-25 on the plasma membrane of Neuro-2A cells. Understanding how these structural elements contribute to the overall association of LC/A1 on the plasma membrane may identify the molecular basis for the LC contribution of BoNT/A1 to high potency.
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Affiliation(s)
- Alexander P. Gardner
- Microbiology and Immunology, Medical College, Wisconsin 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Joseph T. Barbieri
- Microbiology and Immunology, Medical College, Wisconsin 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
- Correspondence: (J.T.B.); (S.P.)
| | - Sabine Pellett
- Department of Bacteriology, Microbial Sciences Building, University of Wisconsin-Madison, 1550 Linden Dr., Madison, WI 53706, USA
- Correspondence: (J.T.B.); (S.P.)
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10
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Bowe BK, Wentz TG, Gregg BM, Tepp WH, Schill KM, Sharma S, Pellett S. Genomic Diversity, Competition, and Toxin Production by Group I and II Clostridium botulinum Strains Used in Food Challenge Studies. Microorganisms 2022; 10:1895. [PMID: 36296172 PMCID: PMC9611418 DOI: 10.3390/microorganisms10101895] [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: 08/26/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) produced by the bacteria Clostridium botulinum are the causative agent of human and animal botulism, a rare but serious and potentially deadly intoxication. Foodborne botulism is caused by the consumption of foods containing BoNTs, which results from contamination of foods with C. botulinum spores and toxin production by the bacteria during growth within the food. Validation of the safety of food products is essential in preventing foodborne botulism, however, limited guidance and standards exist for the selection of strains used in C. botulinum food challenge studies. Sequencing and genomics studies have revealed that C. botulinum is a large, diverse, and polyphyletic species, with physiologic and growth characteristics studied only in a few representatives. Little is known about potential growth competition or effects on toxin production between C. botulinum strains. In this study, we investigated an applied cocktail of ten C. botulinum strains, seven Group I and three Group II. Whole genome SNP alignments revealed that this strain cocktail encompasses the major clades of the Group I and II C. botulinum species. While growth competition appears to exist between several of the strains, the cocktail as a whole resulted in high levels of BoNT production.
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Affiliation(s)
- Brooke Kathryn Bowe
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
- Food Research Institute, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - Travis Gwynn Wentz
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - Brieana Marie Gregg
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - William Howard Tepp
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - Kristin Marie Schill
- Food Research Institute, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
| | - Shashi Sharma
- Division of Microbiology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD 20740, USA
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
- Food Research Institute, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA
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11
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Crystal Structures of the Clostridium botulinum Neurotoxin A6 Cell Binding Domain Alone and in Complex with GD1a Reveal Significant Conformational Flexibility. Int J Mol Sci 2022; 23:ijms23179620. [PMID: 36077016 PMCID: PMC9456117 DOI: 10.3390/ijms23179620] [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: 08/03/2022] [Revised: 08/22/2022] [Accepted: 08/24/2022] [Indexed: 11/26/2022] Open
Abstract
Clostridium botulinum neurotoxin A (BoNT/A) targets the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, by cleaving synaptosomal-associated protein of 25 kDa size (SNAP-25). Cleavage of SNAP-25 results in flaccid paralysis due to repression of synaptic transmission at the neuromuscular junction. This activity has been exploited to treat a range of diseases associated with hypersecretion of neurotransmitters, with formulations of BoNT/A commercially available as therapeutics. Generally, BoNT activity is facilitated by three essential domains within the molecule, the cell binding domain (HC), the translocation domain (HN), and the catalytic domain (LC). The HC, which consists of an N-terminal (HCN) and a C-terminal (HCC) subdomain, is responsible for BoNT’s high target specificity where it forms a dual-receptor complex with synaptic vesicle protein 2 (SV2) and a ganglioside receptor on the surface of motor neurons. In this study, we have determined the crystal structure of botulinum neurotoxin A6 cell binding domain (HC/A6) in complex with GD1a and describe the interactions involved in ganglioside binding. We also present a new crystal form of wild type HC/A6 (crystal form II) where a large ‘hinge motion’ between the HCN and HCC subdomains is observed. These structures, along with a comparison to the previously determined wild type crystal structure of HC/A6 (crystal form I), reveals the degree of conformational flexibility exhibited by HC/A6.
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12
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Byun J, Kwak S, Kwon JH, Shin M, Lee DK, Rhee CH, Kang WH, Oh JW, Cruz DJM. Comparative Pharmacodynamics of Three Different Botulinum Toxin Type A Preparations following Repeated Intramuscular Administration in Mice. Toxins (Basel) 2022; 14:toxins14060365. [PMID: 35737026 PMCID: PMC9227525 DOI: 10.3390/toxins14060365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 12/10/2022] Open
Abstract
Botulinum neurotoxin type A (BoNT/A) causes muscle paralysis by blocking cholinergic signaling at neuromuscular junctions and is widely used to temporarily correct spasticity-related disorders and deformities. The paralytic effects of BoNT/A are time-limited and require repeated injections at regular intervals to achieve long-term therapeutic benefits. Differences in the level and duration of effectivity among various BoNT/A products can be attributed to their unique manufacturing processes, formulation, and noninterchangeable potency units. Herein, we compared the pharmacodynamics of three BoNT/A formulations, i.e., Botox® (onabotulinumtoxinA), Xeomin® (incobotulinumtoxinA), and Coretox®, following repeated intramuscular (IM) injections in mice. Three IM injections of BoNT/A formulations (12 U/kg per dose), 12-weeks apart, were administered at the right gastrocnemius. Local paresis and chemodenervation efficacy were evaluated over 36 weeks using the digit abduction score (DAS) and compound muscle action potential (CMAP), respectively. One week after administration, all three BoNT/A formulations induced peak DAS and maximal reduction of CMAP amplitudes. Among the three BoNT/A formulations, only Coretox® afforded a significant increase in paretic effects and chemodenervation with a prolonged duration of action after repeated injections. These findings suggest that Coretox® may offer a better overall therapeutic performance in clinical settings.
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Affiliation(s)
- Jaeyoon Byun
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
| | - Seongsung Kwak
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
| | - Jin-Hee Kwon
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
| | - Minhee Shin
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
| | - Dong-Kyu Lee
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
| | - Chang-Hoon Rhee
- Medytox Osong R&D Center, 102 Osongsaengmyeong 4-ro, Osong-eup, Heungdeok-gu, Cheongju-si 28161, Korea;
| | - Won-ho Kang
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
| | - Jae-Wook Oh
- Department of Stem Cell and Regenerative Biotechnology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Korea
- Correspondence: (J.-W.O.); (D.J.M.C.); Tel.: +82-2-2049-6271 (J.-W.O.); +82-31-8065-8254 (D.J.M.C.)
| | - Deu John M. Cruz
- Medytox Gwanggyo R&D Center, 114 Central town-ro, Yeongtong-gu, Suwon-si 16506, Korea; (J.B.); (S.K.); (J.-H.K.); (M.S.); (D.-K.L.); (W.-h.K.)
- Correspondence: (J.-W.O.); (D.J.M.C.); Tel.: +82-2-2049-6271 (J.-W.O.); +82-31-8065-8254 (D.J.M.C.)
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13
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Gregory KS, Mahadeva TB, Liu SM, Acharya KR. Structural Features of Clostridium botulinum Neurotoxin Subtype A2 Cell Binding Domain. Toxins (Basel) 2022; 14:toxins14050356. [PMID: 35622602 PMCID: PMC9146395 DOI: 10.3390/toxins14050356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 12/14/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are a group of clostridial toxins that cause the potentially fatal neuroparalytic disease botulism. Although highly toxic, BoNTs are utilized as therapeutics to treat a range of neuromuscular conditions. Several serotypes (BoNT/A-/G, /X) have been identified with vastly differing toxicological profiles. Each serotype can be further sub-categorised into subtypes due to subtle variations in their protein sequence. These minor changes have been attributed to differences in both the duration of action and potency for BoNT/A subtypes. BoNTs are composed of three domains—a cell-binding domain, a translocation domain, and a catalytic domain. In this paper, we present the crystal structures of the botulinum neurotoxin A2 cell binding domain, both alone and in complex with its receptor ganglioside GD1a at 1.63 and 2.10 Å, respectively. The analysis of these structures reveals a potential redox-dependent Lys-O-Cys bridge close to the ganglioside binding site and a hinge motion between the HCN and HCC subdomains. Furthermore, we make a detailed comparison with the previously reported HC/A2:SV2C structure for a comprehensive structural analysis of HC/A2 receptor binding.
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Affiliation(s)
- Kyle S. Gregory
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (T.B.M.)
| | - Tejaswini B. Mahadeva
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (T.B.M.)
| | - Sai Man Liu
- Protein Sciences Department, Ipsen Bioinnovation Limited, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK;
| | - K. Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (T.B.M.)
- Correspondence: ; Tel.: +44-(0)1225-386238
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14
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Fabris F, Šoštarić P, Matak I, Binz T, Toffan A, Simonato M, Montecucco C, Pirazzini M, Rossetto O. Detection of VAMP Proteolysis by Tetanus and Botulinum Neurotoxin Type B In Vivo with a Cleavage-Specific Antibody. Int J Mol Sci 2022; 23:ijms23084355. [PMID: 35457172 PMCID: PMC9024618 DOI: 10.3390/ijms23084355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/17/2022] Open
Abstract
Tetanus and Botulinum type B neurotoxins are bacterial metalloproteases that specifically cleave the vesicle-associated membrane protein VAMP at an identical peptide bond, resulting in inhibition of neuroexocytosis. The minute amounts of these neurotoxins commonly used in experimental animals are not detectable, nor is detection of their VAMP substrate sensitive enough. The immune detection of the cleaved substrate is much more sensitive, as we have previously shown for botulinum neurotoxin type A. Here, we describe the production in rabbit of a polyclonal antibody raised versus a peptide encompassing the 13 residues C-terminal with respect to the neurotoxin cleavage site. The antibody was affinity purified and found to recognize, with high specificity and selectivity, the novel N-terminus of VAMP that becomes exposed after cleavage by tetanus toxin and botulinum toxin type B. This antibody recognizes the neoepitope not only in native and denatured VAMP but also in cultured neurons and in neurons in vivo in neurotoxin-treated mice or rats, suggesting the great potential of this novel tool to elucidate tetanus and botulinum B toxin activity in vivo.
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Affiliation(s)
- Federico Fabris
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
| | - Petra Šoštarić
- Department of Pharmacology, School of Medicine, University of Zagreb, Šalata 11, 10000 Zagreb, Croatia; (P.Š.); (I.M.)
| | - Ivica Matak
- Department of Pharmacology, School of Medicine, University of Zagreb, Šalata 11, 10000 Zagreb, Croatia; (P.Š.); (I.M.)
| | - Thomas Binz
- Institute of Cellular Biochemistry, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany;
| | - Anna Toffan
- Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, Italy;
| | - Morena Simonato
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Interdepartmental Research Center of Myology CIR-Myo, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
- Correspondence: (M.P.); (O.R.)
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy; (F.F.); (C.M.)
- Institute of Neuroscience, Italian Research Council, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy;
- Interdepartmental Research Center of Myology CIR-Myo, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy
- Correspondence: (M.P.); (O.R.)
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15
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Kim HR, Jung Y, Shin J, Park M, Kweon DH, Ban C. Neuron-recognizable characteristics of peptides recombined using a neuronal binding domain of botulinum neurotoxin. Sci Rep 2022; 12:4980. [PMID: 35322139 PMCID: PMC8943039 DOI: 10.1038/s41598-022-09145-5] [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: 12/09/2021] [Accepted: 03/14/2022] [Indexed: 11/09/2022] Open
Abstract
Recombinant peptides were designed using the C-terminal domain (receptor binding domain, RBD) and its subdomain (peptide A2) of a heavy chain of botulinum neurotoxin A-type 1 (BoNT/A1), which can bind to the luminal domain of synaptic vesicle glycoprotein 2C (SV2C-LD). Peptide A2- or RBD-containing recombinant peptides linked to an enhanced green fluorescence protein (EGFP) were prepared by expression in Escherichia coli. A pull-down assay using SV2C-LD-covered resins showed that the recombinant peptides for CDC297 BoNT/A1, referred to EGFP-A2' and EGFP-RBD', exhibited ≥ 2.0-times stronger binding affinity to SV2C-LD than those for the wild-type BoNT/A1. Using bio-layer interferometry, an equilibrium dissociation rate constant (KD) of EGFP-RBD' to SV2C-LD was determined to be 5.45 μM, which is 33.87- and 15.67-times smaller than the KD values for EGFP and EGFP-A2', respectively. Based on confocal laser fluorescence micrometric analysis, the adsorption/absorption of EGFP-RBD' to/in differentiated PC-12 cells was 2.49- and 1.29-times faster than those of EGFP and EGFP-A2', respectively. Consequently, the recombinant peptides acquired reasonable neuron-specific binding/internalizing ability through the recruitment of RBD'. In conclusion, RBDs of BoNTs are versatile protein domains that can be used to mark neural systems and treat a range of disorders in neural systems.
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Affiliation(s)
- Hye Rin Kim
- Department of Integrative Biotechnology, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea
| | - Younghun Jung
- Department of Integrative Biotechnology, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea.,Institute of Biomolecule Control, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea
| | - Jonghyeok Shin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Myungseo Park
- Environmental Health Sciences, School of Public Health, University of Minnesota, Saint Paul, MN, 55108, USA
| | - Dae-Hyuk Kweon
- Department of Integrative Biotechnology, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea. .,Institute of Biomolecule Control, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea. .,Biologics Research Center, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea. .,Interdisciplinary Program in BioCosmetics, Sungkyunkwan University, Seoburo 2066, Suwon, Gyeonggi, 16419, Republic of Korea.
| | - Choongjin Ban
- Department of Environmental Horticulture, University of Seoul, 163 Seoulsiripdaero, Dongdaemun-gu, Seoul, 02504, Republic of Korea.
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16
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Gregory KS, Mojanaga OO, Liu SM, Acharya KR. Crystal Structures of Botulinum Neurotoxin Subtypes A4 and A5 Cell Binding Domains in Complex with Receptor Ganglioside. Toxins (Basel) 2022; 14:toxins14020129. [PMID: 35202156 PMCID: PMC8876736 DOI: 10.3390/toxins14020129] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/02/2022] [Accepted: 02/05/2022] [Indexed: 02/04/2023] Open
Abstract
Botulinum neurotoxins (BoNT) cause the potentially fatal neuroparalytic disease botulism that arises due to proteolysis of a SNARE protein. Each BoNT is comprised of three domains: a cell binding domain (HC), a translocation domain (HN), and a catalytic (Zn2+ endopeptidase) domain (LC). The HC is responsible for neuronal specificity by targeting both a protein and ganglioside receptor at the neuromuscular junction. Although highly toxic, some BoNTs are commercially available as therapeutics for the treatment of a range of neuromuscular conditions. Here we present the crystal structures of two BoNT cell binding domains, HC/A4 and HC/A5, in a complex with the oligosaccharide of ganglioside, GD1a and GM1b, respectively. These structures, along with a detailed comparison with the previously reported apo-structures, reveal the conformational changes that occur upon ganglioside binding and the interactions involved.
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Affiliation(s)
- Kyle S. Gregory
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (O.O.M.)
| | - Otsile O. Mojanaga
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (O.O.M.)
| | - Sai Man Liu
- Protein Sciences Department, Ipsen Bioinnovation Limited, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK;
| | - K. Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK; (K.S.G.); (O.O.M.)
- Correspondence: ; Tel.: +44-(0)1225-386238
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17
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Takeuchi T, Okuno T, Miyashiro A, Kohda T, Miyamoto R, Izumi Y, Kozaki S, Kaji R. Clinical Safety and Tolerability of A2NTX, a Novel Low-Molecular-Weight Neurotoxin Derived from Botulinum Neurotoxin Subtype A2, in Comparison with Subtype A1 Toxins. Toxins (Basel) 2021; 13:824. [PMID: 34822610 PMCID: PMC8623066 DOI: 10.3390/toxins13110824] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/11/2021] [Accepted: 11/16/2021] [Indexed: 11/29/2022] Open
Abstract
All the botulinum type A neurotoxins available for clinical use are of the A1 subtype. We developed a subtype A2 low-molecular-weight (150 kD (kilo Dalton)) neurotoxin (A2NTX) with less spread and faster entry into the motor nerve terminal than A1 in vitro and in vivo. Preliminary clinical studies showed that its efficacy is superior to A1 toxins. We conducted an open study exploring its safety and tolerability profile in comparison with A1LL (LL type A1 toxin, or onabotulinumtoxinA) and a low-molecular-weight (150 kD) A1 neurotoxin (A1NTX). Those who had been using A1LL (n = 90; 50-360 mouse LD50 units) or A1NTX (n = 30; 50-580 units) were switched to A2NTX (n = 120; 25-600 units) from 2010 to 2018 (number of sessions ~27, cumulative doses ~11,640 units per patient). The adverse events for A2NTX included weakness (n = 1, ascribed to alcoholic polyneuropathy), dysphagia (1), local weakness (4), and spread to other muscles (1), whereas those for A1LL or A1NTX comprised weakness (n = 2, A1NTX), dysphagia (8), ptosis (6), local weakness (7), and spread to other muscles (15). After injections, 89 out of 120 patients preferred A2NTX to A1 for the successive sessions. The present study demonstrated that A2NTX had clinical safety up to the dose of 500 units and was well tolerated compared to A1 toxins.
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Affiliation(s)
- Toshiaki Takeuchi
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Tsuyoshi Okuno
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Ai Miyashiro
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Tomoko Kohda
- Department of Veterinary Sciences, School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan; (T.K.); (S.K.)
| | - Ryosuke Miyamoto
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Yuishin Izumi
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
| | - Shunji Kozaki
- Department of Veterinary Sciences, School of Life and Environmental Sciences, Osaka Prefecture University, Osaka 598-8531, Japan; (T.K.); (S.K.)
| | - Ryuji Kaji
- Department of Clinical Neuroscience, Graduate School of Medicine, Tokushima University, Tokushima 770-8503, Japan; (T.T.); (T.O.); (A.M.); (R.M.); (Y.I.)
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18
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Abrahão Cunha TC, Gontijo Couto AC, Januzzi E, Rosa Ferraz Gonçalves RT, Silva G, Silva CR. Analgesic potential of different available commercial brands of botulinum neurotoxin-A in formalin-induced orofacial pain in mice. Toxicon X 2021; 12:100083. [PMID: 34527897 PMCID: PMC8429966 DOI: 10.1016/j.toxcx.2021.100083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/29/2021] [Accepted: 08/26/2021] [Indexed: 11/29/2022] Open
Abstract
The use of botulinum neurotoxin-A (BoNT-A) is an alternative for the management of orofacial pain disorders. Although only Botox has labeled, there are other commercial brands available for use, among them: Dysport, Botulift, Prosigne, and Xeomin. The objective of the present study was to evaluate the possible differences in the antinociceptive effect evoked by different commercially available formulations of BoNT-A in an animal model of inflammatory orofacial pain induced by formalin injection. Male C57/BL6 mice (20–25 g) were submitted to the pre-treatment with five different commercial brands of BoNT-A (Botox, Botulift, Xeomin, Dysport, or Prosigne; with doses between 0.02 and 0.2 Units of Botulinum Toxin, in 20 μL of 0.9% saline) three days prior the 2% formalin injection. All injections were made subcutaneously into the right perinasal area. After formalin injections, nociceptive behaviors like rubbing the place of injection were quantified during the neurogenic (0–5 min) and inflammatory (15–30 min) phases. The treatment using Botox, Botulift, and Xeomin were able to induce antinociceptive effects in both phases of the formalin-induced pain animal model, however, Dysport and Prosigne reduced the response in neither of them. Our data suggest that the treatment using different formulations of BoNT-A is not similar in efficacy as analgesics when evaluated in formalin-induced orofacial pain in mice. Botulinum neurotoxin-a reduced formalin-induced orofacial pain in mice. There are differences in the analgesic potential of different available commercial brands of botulinum neurotoxin-A. Botox, Botulift, Xeomin demonstrated analgesic effect when evaluated in formalin-induced orofacial pain in mice.
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Affiliation(s)
- Thays Crosara Abrahão Cunha
- Post-Graduated Program Genetics and Biochemistry, Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Ana Claudia Gontijo Couto
- Post-Graduated Program Genetics and Biochemistry, Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, MG, Brazil
| | - Eduardo Januzzi
- Post-Graduated Program Orofacial Pain, CIODONTO, Belo Horizonte, MG, Brazil.,Orofacial Pain Department, MaterDei Hospital, Belo Horizonte, MG, Brazil
| | - Rafael Tardin Rosa Ferraz Gonçalves
- Post-Graduated Program Orofacial Pain, CIODONTO, Belo Horizonte, MG, Brazil.,Orofacial Pain Department, MaterDei Hospital, Belo Horizonte, MG, Brazil
| | - Graziella Silva
- Post-Graduated Program Orofacial Pain, CIODONTO, Belo Horizonte, MG, Brazil.,Orofacial Pain Department, MaterDei Hospital, Belo Horizonte, MG, Brazil
| | - Cassia Regina Silva
- Post-Graduated Program Genetics and Biochemistry, Institute of Biotechnology, Federal University of Uberlândia, Uberlândia, MG, Brazil
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19
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Brier S, Rasetti-Escargueil C, Wijkhuisen A, Simon S, Marechal M, Lemichez E, Popoff MR. Characterization of a highly neutralizing single monoclonal antibody to botulinum neurotoxin type A. FASEB J 2021; 35:e21540. [PMID: 33817838 DOI: 10.1096/fj.202002492r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/15/2023]
Abstract
Compared to conventional antisera strategies, monoclonal antibodies (mAbs) represent an alternative and safer way to treat botulism, a fatal flaccid paralysis due to botulinum neurotoxins (BoNTs). In addition, mAbs offer the advantage to be produced in a reproducible manner. We previously identified a unique and potent mouse mAb (TA12) targeting BoNT/A1 with high affinity and neutralizing activity. In this study, we characterized the molecular basis of TA12 neutralization by combining Hydrogen/Deuterium eXchange Mass Spectrometry (HDX-MS) with site-directed mutagenesis and functional studies. We found that TA12 recognizes a conformational epitope located at the interface between the HCN and HCC subdomains of the BoNT/A1 receptor-binding domain (HC ). The TA12-binding interface shares common structural features with the ciA-C2 VHH epitope and lies on the face opposite recognized by ciA-C2- and the CR1/CR2-neutralizing mAbs. The single substitution of N1006 was sufficient to affect TA12 binding to HC confirming the position of the epitope. We further uncovered that the TA12 epitope overlaps with the BoNT/A1-binding site for both the neuronal cell surface receptor synaptic vesicle glycoprotein 2 isoform C (SV2C) and the GT1b ganglioside. Hence, TA12 potently blocks the entry of BoNT/A1 into neurons by interfering simultaneously with the binding of SV2C and to a lower extent GT1b. Our study reveals the unique neutralization mechanism of TA12 and emphasizes on the potential of using single mAbs for the treatment of botulism type A.
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Affiliation(s)
- Sébastien Brier
- Biological NMR Technological Platform, Institut Pasteur, CNRS UMR3528, Paris, France
| | | | - Anne Wijkhuisen
- Département Médicaments et Technologies pour la santé, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Stéphanie Simon
- Département Médicaments et Technologies pour la santé, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Maud Marechal
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
| | - Emmanuel Lemichez
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
| | - Michel R Popoff
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
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20
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Duchesne de Lamotte J, Perrier A, Martinat C, Nicoleau C. Emerging Opportunities in Human Pluripotent Stem-Cells Based Assays to Explore the Diversity of Botulinum Neurotoxins as Future Therapeutics. Int J Mol Sci 2021; 22:7524. [PMID: 34299143 PMCID: PMC8308099 DOI: 10.3390/ijms22147524] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 02/07/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are produced by Clostridium botulinum and are responsible for botulism, a fatal disorder of the nervous system mostly induced by food poisoning. Despite being one of the most potent families of poisonous substances, BoNTs are used for both aesthetic and therapeutic indications from cosmetic reduction of wrinkles to treatment of movement disorders. The increasing understanding of the biology of BoNTs and the availability of distinct toxin serotypes and subtypes offer the prospect of expanding the range of indications for these toxins. Engineering of BoNTs is considered to provide a new avenue for improving safety and clinical benefit from these neurotoxins. Robust, high-throughput, and cost-effective assays for BoNTs activity, yet highly relevant to the human physiology, have become indispensable for a successful translation of engineered BoNTs to the clinic. This review presents an emerging family of cell-based assays that take advantage of newly developed human pluripotent stem cells and neuronal function analyses technologies.
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Affiliation(s)
- Juliette Duchesne de Lamotte
- IPSEN Innovation, 91940 Les Ulis, France;
- I-STEM, INSERM UMR861, Université Evry-Paris Saclay, 91100 Corbeil-Essonne, France
| | - Anselme Perrier
- I-STEM, INSERM UMR861, Université Evry-Paris Saclay, 91100 Corbeil-Essonne, France
- Laboratoire des Maladies Neurodégénératives: Mécanismes, Thérapies, Imagerie, CEA/CNRS UMR9199, Université Paris Saclay, 92265 Fontenay-aux-Roses, France
| | - Cécile Martinat
- I-STEM, INSERM UMR861, Université Evry-Paris Saclay, 91100 Corbeil-Essonne, France
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21
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Leka O, Wu Y, Li X, Kammerer RA. Crystal structure of the catalytic domain of botulinum neurotoxin subtype A3. J Biol Chem 2021; 296:100684. [PMID: 33891946 PMCID: PMC8135040 DOI: 10.1016/j.jbc.2021.100684] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/08/2021] [Accepted: 04/19/2021] [Indexed: 10/28/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are among the most widely used therapeutic proteins; however, only two subtypes within the seven serotypes, BoNT/A1 and BoNT/B1, are currently used for medical and cosmetic applications. Distinct catalytic properties, substrate specificities, and duration of enzymatic activities potentially make other subtypes very attractive candidates to outperform conventional BoNTs in particular therapeutic applications. For example, BoNT/A3 has a significantly shorter duration of action than other BoNT/A subtypes. Notably, BoNT/A3 is the subtype with the least conserved catalytic domain among BoNT/A subtypes. This suggests that the sequence differences, many of which concern the α-exosite, contribute to the observed functional differences in toxin persistence by affecting the binding of the substrate SNAP-25 and/or the stability of the catalytic domain fold. To identify the molecular determinants accounting for the differences in the persistence observed for BoNT/A subtypes, we determined the crystal structure of the catalytic domain of BoNT/A3 (LC/A3). The structure of LC/A3 was found to be very similar to that of LC/A1, suggesting that the overall mode of SNAP-25 binding is common between these two proteins. However, circular dichroism (CD) thermal unfolding experiments demonstrated that LC/A3 is significantly less stable than LC/A1, implying that this might contribute to the reduced toxin persistence of BoNT/A3. These findings could be of interest in developing next-generation therapeutic toxins.
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Affiliation(s)
- Oneda Leka
- The Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Yufan Wu
- The Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Xiaodan Li
- The Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen PSI, Switzerland
| | - Richard A Kammerer
- The Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen PSI, Switzerland.
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22
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Brunt J, van Vliet AHM, Carter AT, Stringer SC, Amar C, Grant KA, Godbole G, Peck MW. Diversity of the Genomes and Neurotoxins of Strains of Clostridium botulinum Group I and Clostridium sporogenes Associated with Foodborne, Infant and Wound Botulism. Toxins (Basel) 2020; 12:toxins12090586. [PMID: 32932818 PMCID: PMC7551954 DOI: 10.3390/toxins12090586] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 12/23/2022] Open
Abstract
Clostridium botulinum Group I and Clostridium sporogenes are closely related bacteria responsible for foodborne, infant and wound botulism. A comparative genomic study with 556 highly diverse strains of C. botulinum Group I and C. sporogenes (including 417 newly sequenced strains) has been carried out to characterise the genetic diversity and spread of these bacteria and their neurotoxin genes. Core genome single-nucleotide polymorphism (SNP) analysis revealed two major lineages; C. botulinum Group I (most strains possessed botulinum neurotoxin gene(s) of types A, B and/or F) and C. sporogenes (some strains possessed a type B botulinum neurotoxin gene). Both lineages contained strains responsible for foodborne, infant and wound botulism. A new C. sporogenes cluster was identified that included five strains with a gene encoding botulinum neurotoxin sub-type B1. There was significant evidence of horizontal transfer of botulinum neurotoxin genes between distantly related bacteria. Population structure/diversity have been characterised, and novel associations discovered between whole genome lineage, botulinum neurotoxin sub-type variant, epidemiological links to foodborne, infant and wound botulism, and geographic origin. The impact of genomic and physiological variability on the botulism risk has been assessed. The genome sequences are a valuable resource for future research (e.g., pathogen biology, evolution of C. botulinum and its neurotoxin genes, improved pathogen detection and discrimination), and support enhanced risk assessments and the prevention of botulism.
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Affiliation(s)
- Jason Brunt
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
- Correspondence: (J.B.); (M.W.P.)
| | - Arnoud H. M. van Vliet
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, UK;
| | - Andrew T. Carter
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
| | - Sandra C. Stringer
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
| | - Corinne Amar
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Kathie A. Grant
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Gauri Godbole
- Gastrointestinal Pathogens Unit, National Infection Service, Public Health England, London NW9 5EQ, UK; (C.A.); (K.A.G.); (G.G.)
| | - Michael W. Peck
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (A.T.C.); (S.C.S.)
- Correspondence: (J.B.); (M.W.P.)
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23
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Davies JR, Britton A, Liu SM, Acharya KR. High-resolution crystal structures of the botulinum neurotoxin binding domains from subtypes A5 and A6. FEBS Open Bio 2020; 10:1474-1481. [PMID: 32654405 PMCID: PMC7396429 DOI: 10.1002/2211-5463.12931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 11/10/2022] Open
Abstract
Clostridium botulinum neurotoxins (BoNTs) cause flaccid paralysis through inhibition of acetylcholine release from motor neurons; however, at tiny doses, this property is exploited for use as a therapeutic. Each member of the BoNT family of proteins consists of three distinct domains: a binding domain that targets neuronal cell membranes (HC ), a translocation domain (HN ) and a catalytic domain (LC). Here, we present high-resolution crystal structures of the binding domains of BoNT subtypes/A5 (HC /A5) and/A6 (HC /A6). These structures show that the core fold identified in other subtypes is maintained, but with subtle differences at the expected receptor-binding sites.
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Affiliation(s)
- Jonathan R Davies
- Department of Biology and Biochemistry, Claverton Down, University of Bath, Bath, UK.,Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Amy Britton
- Department of Biology and Biochemistry, Claverton Down, University of Bath, Bath, UK
| | - Sai Man Liu
- Ipsen Bioinnovation Limited, Milton Park, Abingdon, UK
| | - K Ravi Acharya
- Department of Biology and Biochemistry, Claverton Down, University of Bath, Bath, UK
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24
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Kohda T, Tsukamoto K, Torii Y, Kozaki S, Mukamoto M. Translocation domain of botulinum neurotoxin A subtype 2 potently induces entry into neuronal cells. Microbiol Immunol 2020; 64:502-511. [PMID: 32301520 DOI: 10.1111/1348-0421.12796] [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: 11/19/2019] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 11/27/2022]
Abstract
Botulinum neurotoxin (BoNT) is the causative agent of botulism in humans and animals. Only BoNT serotype A subtype 1 (BoNT/A1) is used clinically because of its high potency and long duration of action. BoNT/A1 and BoNT/A subtype 2 (BoNT/A2) have a high degree of amino acid sequence similarity in the light chain (LC) (96%), whereas their N-and C-terminal heavy chain (HN and HC ) differ by 13%. The LC acts as a zinc-dependent endopeptidase, HN as the translocation domain, and HC as the receptor-binding domain. BoNT/A2 and BoNT/A1 had similar potency in the mouse bioassay, but BoNT/A2 entered faster and more efficiently into neuronal cells. To identify the domains responsible for these characteristics, HN of BoNT/A1 and BoNT/A2 was exchanged to construct chimeric BoNT/A121 and BoNT/A212. After expression in Escherichia coli, chimeric and wild-type BoNT/As were purified as single-chain proteins and activated by conversion to disulfide-linked dichains. The toxicities of recombinant wild-type and chimeric BoNT/As were similar, but dropped to 60% compared with the values of native BoNT/As. The relative orders of SNAP-25 cleavage activity in neuronal cells and toxicity differed. BoNT/A121 and recombinant BoNT/A2 have similar SNAP-25 cleavage activity. BoNT/A2 HN is possibly responsible for the higher potency of BoNT/A2 than BoNT/A1.
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Affiliation(s)
- Tomoko Kohda
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Kentaro Tsukamoto
- Department of Microbiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
| | - Yasushi Torii
- Department of Animal Science, Tokyo University of Agriculture, Atsugi, Kanagawa, Japan
| | - Shunji Kozaki
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
| | - Masafumi Mukamoto
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka, Japan
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Brunt J, van Vliet AHM, Stringer SC, Carter AT, Lindström M, Peck MW. Pan-Genomic Analysis of Clostridium botulinum Group II (Non-Proteolytic C. botulinum) Associated with Foodborne Botulism and Isolated from the Environment. Toxins (Basel) 2020; 12:E306. [PMID: 32397147 PMCID: PMC7291236 DOI: 10.3390/toxins12050306] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 12/21/2022] Open
Abstract
The neurotoxin formed by Clostridium botulinum Group II is a major cause of foodborne botulism, a deadly intoxication. This study aims to understand the genetic diversity and spread of C. botulinum Group II strains and their neurotoxin genes. A comparative genomic study has been conducted with 208 highly diverse C. botulinum Group II strains (180 newly sequenced strains isolated from 16 countries over 80 years, 28 sequences from Genbank). Strains possessed a single type B, E, or F neurotoxin gene or were closely related strains with no neurotoxin gene. Botulinum neurotoxin subtype variants (including novel variants) with a unique amino acid sequence were identified. Core genome single-nucleotide polymorphism (SNP) analysis identified two major lineages-one with type E strains, and the second dominated by subtype B4 strains with subtype F6 strains. This study revealed novel details of population structure/diversity and established relationships between whole-genome lineage, botulinum neurotoxin subtype variant, association with foodborne botulism, epidemiology, and geographical source. Additionally, the genome sequences represent a valuable resource for the research community (e.g., understanding evolution of C. botulinum and its neurotoxin genes, dissecting key aspects of C. botulinum Group II biology). This may contribute to improved risk assessments and the prevention of foodborne botulism.
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Affiliation(s)
- Jason Brunt
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge CB3 0AS, UK
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (S.C.S.); (A.T.C.)
| | - Arnoud H. M. van Vliet
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, UK;
| | - Sandra C. Stringer
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (S.C.S.); (A.T.C.)
| | - Andrew T. Carter
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (S.C.S.); (A.T.C.)
| | - Miia Lindström
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, 00014 Helsinki, Finland;
| | - Michael W. Peck
- Gut Health and Food Safety, Quadram Institute, Norwich Research Park, Norwich NR4 7UQ, UK; (S.C.S.); (A.T.C.)
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26
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Gregory KS, Liu SM, Acharya KR. Crystal structure of botulinum neurotoxin subtype A3 cell binding domain in complex with GD1a co-receptor ganglioside. FEBS Open Bio 2020; 10:298-305. [PMID: 31945264 PMCID: PMC7050238 DOI: 10.1002/2211-5463.12790] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/07/2020] [Accepted: 01/10/2020] [Indexed: 01/20/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are one of the most toxic proteins known to humans. Their molecular structure is comprised of three essential domains—a cell binding domain (HC), translocation domain and catalytic domain (light chain) . The HC domain facilitates the highly specific binding of BoNTs to the neuronal membrane via a dual‐receptor complex involving a protein receptor and a ganglioside. Variation in activity/toxicity across subtypes of serotype A has been attributed to changes in protein and ganglioside interactions, and their implications are important in the design of novel BoNT‐based therapeutics. Here, we present the structure of BoNT/A3 cell binding domain (HC/A3) in complex with the ganglioside GD1a at 1.75 Å resolution. The structure revealed that six residues interact with the three outermost monosaccharides of GD1a through several key hydrogen bonding interactions. A detailed comparison of structures of HC/A3 with HC/A1 revealed subtle conformational differences at the ganglioside binding site upon carbohydrate binding.
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Affiliation(s)
- Kyle S Gregory
- Department of Biology and Biochemistry, Claverton Down, University of Bath, UK
| | | | - K Ravi Acharya
- Department of Biology and Biochemistry, Claverton Down, University of Bath, UK
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27
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Pellett S, Tepp WH, Johnson EA. Critical Analysis of Neuronal Cell and the Mouse Bioassay for Detection of Botulinum Neurotoxins. Toxins (Basel) 2019; 11:E713. [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.
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Affiliation(s)
| | | | - Eric A. Johnson
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Dr, Madison, WI 53706, USA; (S.P.); (W.H.T.)
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28
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Structural insights into the interaction of botulinum neurotoxin a with its neuronal receptor SV2C. Toxicon 2019; 175:36-43. [PMID: 31783045 DOI: 10.1016/j.toxicon.2019.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 11/08/2019] [Accepted: 11/25/2019] [Indexed: 11/23/2022]
Abstract
A dual-receptor interaction with a polysialoganglioside and synaptic vesicle glycoprotein 2 (SV2) is required for botulinum neurotoxin A (BoNT) toxicity. Here, we review what is currently known about the BoNT/A-SV2 interaction based on structural studies. Currently, five crystal structures of the receptor-binding domain (Hc) of BoNT subtypes A1 and A2 complexed to the large luminal domain (LD4) of SV2C have been determined. On the basis of the available structures, we will discuss the importance of protein-protein and protein-carbohydrate interactions for BoNT/A toxicity as well as the high plasticity of BoNT/A for receptor recognition by tolerating a variety of side-chain interactions at the interface. A plausible explanation how receptor-binding specificity of BoNT/A may be achieved without an extensive and conserved side chain-side chain interaction network will be provided.
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29
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Tables of Toxicity of Botulinum and Tetanus Neurotoxins. Toxins (Basel) 2019; 11:toxins11120686. [PMID: 31771110 PMCID: PMC6950492 DOI: 10.3390/toxins11120686] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/18/2019] [Accepted: 11/19/2019] [Indexed: 11/17/2022] Open
Abstract
Tetanus and botulinum neurotoxins are the most poisonous substances known, so much so as to be considered for a possible terrorist use. At the same time, botulinum neurotoxin type A1 is successfully used to treat a variety of human syndromes characterized by hyperactive cholinergic nerve terminals. The extreme toxicity of these neurotoxins is due to their neurospecificity and to their metalloprotease activity, which results in the deadly paralysis of tetanus and botulism. Recently, many novel botulinum neurotoxins and some botulinum-like toxins have been discovered. This large number of toxins differs in terms of toxicity and biological activity, providing a potential goldmine for novel therapeutics and for new molecular tools to dissect vesicular trafficking, fusion, and exocytosis. The scattered data on toxicity present in the literature require a systematic organization to be usable by scientists and clinicians. We have assembled here the data available in the literature on the toxicity of these toxins in different animal species. The internal comparison of these data provides insights on the biological activity of these toxins.
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30
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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.
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Affiliation(s)
- Oliver G Weingart
- Institute for Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland
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31
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Seo MS, Kim YI, Kang KK, Oh SK, Sung SE, Jung YS, Cho JY, Song H, Hwang DY, Park SJ, Kim KS. Comparison study of the response with botulinum toxin muscle injection in the ICR mice from three different sources. Lab Anim Res 2019; 35:11. [PMID: 32257899 PMCID: PMC7081521 DOI: 10.1186/s42826-019-0010-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/04/2019] [Indexed: 11/10/2022] Open
Abstract
Botulinum-toxin A (BoNT/A) is a widely used not only for cosmetics but also for various experimental purposes including muscle-related research. In this study, we applied BoNT/A to mouse muscle of three different sources to compare and evaluate the biological and pathological response. The three different mouse sources consist of Korl:ICR (Korea FDA source), A:ICR (USA source) and B:ICR (Japan source) which were purchased from each different vendors. To compare the responses of ICR mice with BoNT/A muscle injection, we examined the body weight, hematological and serum biochemistry analysis. Also, we evaluated the muscle change by histopathological analysis and gene expression patterns of muscle-related target by qPCR. The body weight gain was decreased in the BoNT/A-treated group compared with the control group. In clinical pathologic analysis and gene expression patterns, the data showed that the responses in the BoNT/A-treated group were similar compared with the control group. Decreased muscle fiber was observed in BoNT/A-treated group compared with control group, while Korl:ICR showed a little low response with the other mouse sources. In conclusion, our results suggest that three different sources ICR mice (Korl:ICR, A:ICR and B:ICR) have a similar biological and pathological responses in BoNT/A muscle injection.
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Affiliation(s)
- Min-Soo Seo
- 1Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | | | - Kyung-Ku Kang
- 1Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Se-Kyung Oh
- 1Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Soo-Eun Sung
- 1Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Young-Suk Jung
- 3Department of Pharmacy, College of Pharmacy, Pusan National University, Busan, Korea
| | - Joon Yong Cho
- 4Department of Health and Exercise Science, Korea National Sport University, 88-15 Oryung-dong, Songpa-gu, Seoul, Korea
| | - HyunKeun Song
- Central Research Institute, Kine sciences, F1, Milovany, 28, Inchon-ro, Seongbuk-gu, Seoul, Korea
| | - Dae Youn Hwang
- 6Department of Biomaterials Science, College of Natural Resources & Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, Korea
| | - Sang-Joon Park
- 7Laboratory of Histology, College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
| | - Kil Soo Kim
- 1Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea.,8College of Veterinary Medicine, Kyungpook National University, Daegu, Korea
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32
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Pellett S, Tepp WH, Johnson EA. Botulinum neurotoxins A, B, C, E, and F preferentially enter cultured human motor neurons compared to other cultured human neuronal populations. FEBS Lett 2019; 593:2675-2685. [PMID: 31240706 PMCID: PMC7751886 DOI: 10.1002/1873-3468.13508] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/11/2022]
Abstract
Human-induced pluripotent stem cell (hiPSC)-derived neurons can be exquisitely sensitive to botulinum neurotoxins (BoNTs), exceeding sensitivity of the traditionally used mouse bioassay. In this report, four defined hiPSC-derived neuronal populations including primarily GABAergic, glutamatergic, dopaminergic, and motor neurons were examined for BoNT/A, B, C, D, E, and F sensitivity. The data indicate that sensitivity varies markedly for the BoNTs tested. Motor neurons are significantly more sensitive than other neuron types for all BoNTs except BoNT/D. Examination of SNARE protein levels and BoNT-specific cell surface protein receptors reveals few differences between the cell types except greater expression levels of the receptor protein SV2C and synapsin-IIa in motor neurons. This indicates that differential toxicity of BoNTs for motor neurons compared to other neuronal cell types involves multiple mechanisms.
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Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin-Madison, WI, USA
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin-Madison, WI, USA
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin-Madison, WI, USA
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33
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Moritz MS, Tepp WH, Inzalaco HN, Johnson EA, Pellett S. Comparative functional analysis of mice after local injection with botulinum neurotoxin A1, A2, A6, and B1 by catwalk analysis. Toxicon 2019; 167:20-28. [PMID: 31181297 PMCID: PMC6688953 DOI: 10.1016/j.toxicon.2019.06.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/20/2019] [Accepted: 06/03/2019] [Indexed: 01/10/2023]
Abstract
Botulinum neurotoxins (BoNTs) are potent neurotoxins and are the causative agent of botulism, as well as valuable pharmaceuticals. BoNTs are divided into seven serotypes that comprise over 40 reported subtypes. BoNT/A1 and BoNT/B1 are currently the only subtypes approved for pharmaceutical use in the USA. While several other BoNT subtypes including BoNT/A2 and/A6 have been proposed as promising pharmaceuticals, detailed characterization using in vivo assays are essential to determine their pharmaceutical characteristics compared to the currently used BoNT/A1 and/B1. Several methods for studying BoNTs in mice are being used, but no objective and quantitative assay for assessment of functional outcomes after injection has been described. Here we describe the use of CatWalk XT as a new analytical tool for the objective and quantitative analysis of the paralytic effect after local intramuscular injection of BoNT subtypes A1, A2, A6, and B1. Catwalk is a sophisticated gait and locomotion analysis system that quantitatively analyzes a rodent's paw print dimensions and footfall patterns while traversing a glass plate during unforced walk. Significant changes were observed in several gait parameters in mice after local intramuscular injection of all tested BoNT subtypes, however, no changes were observed in mice injected intraperitoneally with the same BoNTs. While a clear difference in time to peak paralysis was observed between BoNT/A1 and/B1, injection of all four toxins resulted in a deficit in the injected limb with the other limbs functionally compensating and with no qualitative differences between the four BoNT subtypes. The presented data demonstrate the utility of CatWalk as a tool for functional outcomes after local BoNT injection through its ability to collect large amounts of quantitative data and objectively analyze sensitive changes in static and dynamic gait parameters.
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Affiliation(s)
- Molly S Moritz
- University of Wisconsin-Madison, Dept. of Bacteriology, USA
| | - William H Tepp
- University of Wisconsin-Madison, Dept. of Bacteriology, USA
| | | | - Eric A Johnson
- University of Wisconsin-Madison, Dept. of Bacteriology, USA
| | - Sabine Pellett
- University of Wisconsin-Madison, Dept. of Bacteriology, USA.
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von Berg L, Stern D, Pauly D, Mahrhold S, Weisemann J, Jentsch L, Hansbauer EM, Müller C, Avondet MA, Rummel A, Dorner MB, Dorner BG. Functional detection of botulinum neurotoxin serotypes A to F by monoclonal neoepitope-specific antibodies and suspension array technology. Sci Rep 2019; 9:5531. [PMID: 30940836 PMCID: PMC6445094 DOI: 10.1038/s41598-019-41722-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/15/2019] [Indexed: 12/26/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are the most potent toxins known and cause the life threatening disease botulism. Sensitive and broad detection is extremely challenging due to the toxins' high potency and molecular heterogeneity with several serotypes and more than 40 subtypes. The toxicity of BoNT is mediated by enzymatic cleavage of different synaptic proteins involved in neurotransmitter release at serotype-specific cleavage sites. Hence, active BoNTs can be monitored and distinguished in vitro by detecting their substrate cleavage products. In this work, we developed a comprehensive panel of monoclonal neoepitope antibodies (Neo-mAbs) highly specific for the newly generated N- and/or C-termini of the substrate cleavage products of BoNT serotypes A to F. The Neo-mAbs were implemented in a set of three enzymatic assays for the simultaneous detection of two BoNT serotypes each by monitoring substrate cleavage on colour-coded magnetic Luminex-beads. For the first time, all relevant serotypes could be detected in parallel by a routine in vitro activity assay in spiked serum and food samples yielding excellent detection limits in the range of the mouse bioassay or better (0.3-80 pg/mL). Therefore, this work represents a major step towards the replacement of the mouse bioassay for botulism diagnostics.
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Affiliation(s)
- Laura von Berg
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
| | - Daniel Stern
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
| | - Diana Pauly
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
- Department of Ophthalmology, University Hospital Regensburg, Regensburg, 93053, Germany
| | - Stefan Mahrhold
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Jasmin Weisemann
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Lisa Jentsch
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
| | - Eva-Maria Hansbauer
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
| | - Christian Müller
- Spiez Laboratory, Federal Office for Civil Protection, Spiez, 3700, Switzerland
| | - Marc A Avondet
- Spiez Laboratory, Federal Office for Civil Protection, Spiez, 3700, Switzerland
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, 30625, Hannover, Germany
| | - Martin B Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany
| | - Brigitte G Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, Berlin, 13353, Germany.
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Abstract
Botulinum neurotoxins (BoNTs) are a family of bacterial protein toxins produced by various Clostridium species. They are traditionally classified into seven major serotypes (BoNT/A-G). Recent progress in sequencing microbial genomes has led to an ever-growing number of subtypes, chimeric toxins, BoNT-like toxins, and remotely related BoNT homologs, constituting an expanding BoNT superfamily. Recent structural studies of BoNTs, BoNT progenitor toxin complexes, tetanus neurotoxin (TeNT), toxin-receptor complexes, and toxin-substrate complexes have provided mechanistic understandings of toxin functions and the molecular basis for their variations. The growing BoNT superfamily of toxins present a natural repertoire that can be explored to develop novel therapeutic toxins, and the structural understanding of their variations provides a knowledge basis for engineering toxins to improve therapeutic efficacy and expand their clinical applications.
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Affiliation(s)
- Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA, USA.
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
- Department of Surgery, Harvard Medical School, Boston, MA, USA.
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
- Department of Experimental Medical Science, Lund University, Lund, Sweden.
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Abstract
Botulinum neurotoxins (BoNTs) have proved to be an effective treatment for a large number of neuropathic conditions. BoNTs comprise a large family of zinc metalloproteases, but BoNT/A1 is used nearly exclusively for pharmaceutical purposes. The genetic inactivation of a second BoNT gene in the native strain enabled expression and isolation of a single BoNT/A6 from cultures. Its characterization indicated that BoNT/A subtype A6 has a long duration of action comparable to A1, while it enters neurons faster and more efficiently and remains more localized after intramuscular injection. These characteristics of BoNT/A6 are of interest for potential use of BoNT/A6 as a novel BoNT-based therapeutic that is effective and has a fast onset, an improved safety profile, and a long duration of action. Use of BoNT/A6 as a pharmaceutical also has the potential to reveal novel treatment motifs compared to currently used treatments. Botulinum neurotoxins (BoNTs), the most potent toxins known to humans and the causative agent of botulism, exert their effect by entering motor neurons and cleaving and inactivating SNARE proteins, which are essential for neurotransmitter release. BoNTs are proven, valuable pharmaceuticals used to treat more than 200 neuronal disorders. BoNTs comprise 7 serotypes and more than 40 isoforms (subtypes). BoNT/A1 is the only A-subtype used clinically due to its high potency and long duration of action. While other BoNT/A subtypes have been purified and described, only BoNT/A2 is being investigated as an alternative to BoNT/A1. Here we describe subtype BoNT/A6 with improved pharmacological properties compared to BoNT/A1. It was isolated from Clostridium botulinum CDC41370, which produces both BoNT/B2 and BoNT/A6. The gene encoding BoNT/B2 was genetically inactivated, and A6 was isolated to greater than 95% purity. A6 was highly potent in cultured primary rodent neuronal cultures and in human induced pluripotent stem cell-derived neurons, requiring 20-fold less toxin to cause 50% SNAP-25 cleavage than A1. Second, A6 entered hiPSCs faster and more efficiently than A1 and yet had a long duration of action similar to BoNT/A1. Third, BoNT/A6 had similar LD50 as BoNT/A1 after intraperitoneal injection in mice; however, local intramuscular injection resulted in less systemic toxicity than BoNT/A1 and a higher (i.m.) LD50, indicating its potential as a safer pharmaceutical. These data suggest novel characteristics of BoNT/A6 and its potential as an improved pharmaceutical due to more efficient neuronal cell entry, greater ability to remain localized at the injection site, and a long duration. IMPORTANCE Botulinum neurotoxins (BoNTs) have proved to be an effective treatment for a large number of neuropathic conditions. BoNTs comprise a large family of zinc metalloproteases, but BoNT/A1 is used nearly exclusively for pharmaceutical purposes. The genetic inactivation of a second BoNT gene in the native strain enabled expression and isolation of a single BoNT/A6 from cultures. Its characterization indicated that BoNT/A subtype A6 has a long duration of action comparable to A1, while it enters neurons faster and more efficiently and remains more localized after intramuscular injection. These characteristics of BoNT/A6 are of interest for potential use of BoNT/A6 as a novel BoNT-based therapeutic that is effective and has a fast onset, an improved safety profile, and a long duration of action. Use of BoNT/A6 as a pharmaceutical also has the potential to reveal novel treatment motifs compared to currently used treatments.
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Variability of Botulinum Toxins: Challenges and Opportunities for the Future. Toxins (Basel) 2018; 10:toxins10090374. [PMID: 30217070 PMCID: PMC6162648 DOI: 10.3390/toxins10090374] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/03/2018] [Accepted: 09/08/2018] [Indexed: 12/31/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are the most potent known toxins, and are therefore classified as extremely harmful biological weapons. However, BoNTs are therapeutic drugs that are widely used and have an increasing number of applications. BoNTs show a high diversity and are divided into multiple types and subtypes. Better understanding of the activity at the molecular and clinical levels of the natural BoNT variants as well as the development of BoNT-based chimeric molecules opens the door to novel medical applications such as silencing the sensory neurons at targeted areas and dermal restoration. This short review is focused on BoNTs’ variability and the opportunities or challenges posed for future clinical applications.
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Torii Y, Sasaki M, Shin MC, Akaike N, Kaji R. Comparison of efficacy and toxicity between botulinum toxin subtypes A1 and A2 in cynomolgus macaques. Toxicon 2018; 153:114-119. [PMID: 30193802 DOI: 10.1016/j.toxicon.2018.08.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/15/2018] [Accepted: 08/30/2018] [Indexed: 11/18/2022]
Abstract
Botulinum toxin type A (subtype A1) is used as therapeutic agent for some neurological disorders causing spasticity. The toxin products have an upper dosage limit, and their adverse events, such as side effects of diffusion following high-dose administration, have become serious issues. Therefore, a preparation with greater therapeutic efficacy at lower dosages and less diffusion in the body is desired. We have attempted to produce neurotoxin derived from subtype A2 (A2NTX), which has a different amino acid sequence from that of neurotoxin derived from subtype A1. In this study, to investigate whether A2NTX is applicable for treatment, we compared the muscle relaxation effects and the toxicity between A1LL and A2NTX in adult cynomolgus macaques. In the isometric muscle contraction test elicited by 30 Hz tetanus stimulation, the contractions observed in the 0.4 U/site A1LL-treated group were similar in value to those in the 0.13 U/site A2NTX-treated group. In the toxicity test, the 12 and 24 U/kg A1LL- and A2NTX-treated groups all exhibited similar signs of toxicity regarding symptoms, rate of weight loss, and decrease in the length of the right lower leg perimeter. Thus, A2NTX demonstrated approximately 3.0-times higher muscle relaxation activity than A1LL, and their toxicity was equivalent. This study suggested that A2NTX products are more suitable for the treatment of neurological disorders.
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Affiliation(s)
- Yasushi Torii
- Department of Animal Science, Tokyo University of Agriculture, Kanagawa, 243-0034, Japan.
| | | | - Min-Chul Shin
- Research Division for Life Science, Kumamoto Health Science University, Kumamoto, 861-5598, Japan
| | - Norio Akaike
- Research Division for Life Science, Kumamoto Health Science University, Kumamoto, 861-5598, Japan; Research Division for Clinical Pharmacology, Kumamoto Kinoh Hospital, Kumamoto, 860-8518, Japan
| | - Ryuji Kaji
- Graduate School of Medicine, University of Tokushima, Tokushima, 770-8503, Japan
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Sikorra S, Skiba M, Dorner MB, Weisemann J, Weil M, Valdezate S, Davletov B, Rummel A, Dorner BG, Binz T. Botulinum Neurotoxin F Subtypes Cleaving the VAMP-2 Q 58⁻K 59 Peptide Bond Exhibit Unique Catalytic Properties and Substrate Specificities. Toxins (Basel) 2018; 10:toxins10080311. [PMID: 30071628 PMCID: PMC6116196 DOI: 10.3390/toxins10080311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 07/23/2018] [Accepted: 07/30/2018] [Indexed: 11/16/2022] Open
Abstract
In the recent past, about 40 botulinum neurotoxin (BoNT) subtypes belonging to serotypes A, B, E, and F pathogenic to humans were identified among hundreds of independent isolates. BoNTs are the etiological factors of botulism and represent potential bioweapons; however, they are also recognized pharmaceuticals for the efficient counteraction of hyperactive nerve terminals in a variety of human diseases. The detailed biochemical characterization of subtypes as the basis for development of suitable countermeasures and possible novel therapeutic applications is lagging behind the increase in new subtypes. Here, we report the primary structure of a ninth subtype of BoNT/F. Its amino-acid sequence diverges by at least 8.4% at the holotoxin and 13.4% at the enzymatic domain level from all other known BoNT/F subtypes. We found that BoNT/F9 shares the scissile Q58/K59 bond in its substrate vesicle associated membrane protein 2 with the prototype BoNT/F1. Comparative biochemical analyses of four BoNT/F enzymatic domains showed that the catalytic efficiencies decrease in the order F1 > F7 > F9 > F6, and vary by up to a factor of eight. KM values increase in the order F1 > F9 > F6 ≈ F7, whereas kcat decreases in the order F7 > F1 > F9 > F6. Comparative substrate scanning mutagenesis studies revealed a unique pattern of crucial substrate residues for each subtype. Based upon structural coordinates of F1 bound to an inhibitor polypeptide, the mutational analyses suggest different substrate interactions in the substrate binding channel of each subtype.
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Affiliation(s)
- Stefan Sikorra
- Institute of Cell Biochemistry, OE 4310, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Martin Skiba
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Martin B Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Jasmin Weisemann
- Institute of Toxicology, OE 5340, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Mirjam Weil
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Sylvia Valdezate
- Reference and Research Laboratory for Taxonomy, Spanish National Centre of Microbiology, Institute of Health Carlos III, 28220 Madrid, Spain.
| | - Bazbek Davletov
- Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
| | - Andreas Rummel
- Institute of Toxicology, OE 5340, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
| | - Brigitte G Dorner
- Biological Toxins (ZBS 3), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, 13353 Berlin, Germany.
| | - Thomas Binz
- Institute of Cell Biochemistry, OE 4310, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany.
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Light Chain Diversity among the Botulinum Neurotoxins. Toxins (Basel) 2018; 10:toxins10070268. [PMID: 30004421 PMCID: PMC6070880 DOI: 10.3390/toxins10070268] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 12/30/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are produced by several species of clostridium. There are seven immunologically unique BoNT serotypes (A⁻G). The Centers for Disease Control classifies BoNTs as 'Category A' select agents and are the most lethal protein toxins for humans. Recently, BoNT-like proteins have also been identified in several non-clostridia. BoNTs are di-chain proteins comprised of an N-terminal zinc metalloprotease Light Chain (LC) and a C-terminal Heavy Chain (HC) which includes the translocation and receptor binding domains. The two chains are held together by a disulfide bond. The LC cleaves Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs). The cleavage of SNAREs inhibits the fusion of synaptic vesicles to the cell membrane and the subsequent release of acetylcholine, which results in flaccid paralysis. The LC controls the catalytic properties and the duration of BoNT action. This review discusses the mechanism for LC catalysis, LC translocation, and the basis for the duration of LC action. Understanding these properties of the LC may expand the applications of BoNT as human therapies.
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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: 34] [Impact Index Per Article: 5.7] [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.
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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
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Kohda T, Nakamura K, Hosomi K, Torii Y, Kozaki S, Mukamoto M. Characterization of the functional activity of botulinum neurotoxin subtype B6. Microbiol Immunol 2018; 61:482-489. [PMID: 28898517 DOI: 10.1111/1348-0421.12540] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/30/2017] [Accepted: 09/07/2017] [Indexed: 12/01/2022]
Abstract
Clostridium botulinum produces the highly potent neurotoxin, botulinum neurotoxin (BoNT), which is classified into seven serotypes (A-G); the subtype classification is confirmed by the diversity of amino acid sequences among the serotypes. BoNT from the Osaka05 strain is associated with type B infant botulism and has been classified as BoNT/B subtype B6 (BoNT/B6) by phylogenetic analysis and the antigenicity of its C-terminal heavy chain (HC ) domain. However, the molecular bases for its properties, including its potency, are poorly understood. In this study, BoNT/B6 holotoxin was purified and the biological activity and receptor binding activity of BoNT/B6 compared with those of the previously-characterized BoNT/B1 and BoNT/B2 subtypes. The derivative BoNT/B6 was found to be already nicked and in an activated form, indicating that endogenous protease production may be higher in this strain than in the other two strains. BoNT/B1 exhibited the greatest lethal activity in mice, followed by BoNT/B6, which is consistent with the sensitivity of PC12 cells. No significant differences were seen in the enzymatic activities of the BoNT/Bs against their substrate. HC /B1 and HC /B6 exhibited similar binding affinities to synaptotagmin II (SytII), which is a specific protein receptor for BoNT/B. Binding to the SytII/ganglioside complex is functionally related to the toxic action; however, the receptor recognition sites are conserved. These results suggest that the distinct characteristics and differences in biological sensitivity of BoNT/B6 may be attributable to the function of its Hc .domain.
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Affiliation(s)
- Tomoko Kohda
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, 598-8531 Osaka, Japan
| | - Keiji Nakamura
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, 598-8531 Osaka, Japan
| | - Koji Hosomi
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, 598-8531 Osaka, Japan
| | - Yasushi Torii
- Department of Animal Science, Tokyo University of Agriculture, Funako, Atsugi, 243-0034 Kanagawa, Japan
| | - Shunji Kozaki
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, 598-8531 Osaka, Japan
| | - Masafumi Mukamoto
- Department of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, 598-8531 Osaka, Japan
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Fonfria E, Maignel J, Lezmi S, Martin V, Splevins A, Shubber S, Kalinichev M, Foster K, Picaut P, Krupp J. The Expanding Therapeutic Utility of Botulinum Neurotoxins. Toxins (Basel) 2018; 10:E208. [PMID: 29783676 PMCID: PMC5983264 DOI: 10.3390/toxins10050208] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/15/2018] [Accepted: 05/16/2018] [Indexed: 12/11/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is a major therapeutic agent that is licensed in neurological indications, such as dystonia and spasticity. The BoNT family, which is produced in nature by clostridial bacteria, comprises several pharmacologically distinct proteins with distinct properties. In this review, we present an overview of the current therapeutic landscape and explore the diversity of BoNT proteins as future therapeutics. In recent years, novel indications have emerged in the fields of pain, migraine, overactive bladder, osteoarthritis, and wound healing. The study of biological effects distal to the injection site could provide future opportunities for disease-tailored BoNT therapies. However, there are some challenges in the pharmaceutical development of BoNTs, such as liquid and slow-release BoNT formulations; and, transdermal, transurothelial, and transepithelial delivery. Innovative approaches in the areas of formulation and delivery, together with highly sensitive analytical tools, will be key for the success of next generation BoNT clinical products.
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Affiliation(s)
- Elena Fonfria
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Jacquie Maignel
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Stephane Lezmi
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Vincent Martin
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
| | - Andrew Splevins
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Saif Shubber
- Ipsen Biopharm Ltd., Wrexham Industrial Estate, 9 Ash Road, Wrexham LL13 9UF, UK.
| | | | - Keith Foster
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, UK.
| | - Philippe Picaut
- Ipsen Bioscience, 650 Kendall Street, Cambridge, MA 02142, USA.
| | - Johannes Krupp
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
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Tehran DA, Pirazzini M. Novel Botulinum Neurotoxins: Exploring Underneath the Iceberg Tip. Toxins (Basel) 2018; 10:toxins10050190. [PMID: 29748471 PMCID: PMC5983246 DOI: 10.3390/toxins10050190] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 05/05/2018] [Accepted: 05/08/2018] [Indexed: 12/26/2022] Open
Abstract
Botulinum neurotoxins (BoNTs), the etiological agents of botulism, are the deadliest toxins known to humans. Yet, thanks to their biological and toxicological features, BoNTs have become sophisticated tools to study neuronal physiology and valuable therapeutics for an increasing number of human disorders. BoNTs are produced by multiple bacteria of the genus Clostridium and, on the basis of their different immunological properties, were classified as seven distinct types of toxin. BoNT classification remained stagnant for the last 50 years until, via bioinformatics and high-throughput sequencing techniques, dozens of BoNT variants, novel serotypes as well as BoNT-like toxins within non-clostridial species have been discovered. Here, we discuss how the now “booming field” of botulinum neurotoxin may shed light on their evolutionary origin and open exciting avenues for future therapeutic applications.
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Affiliation(s)
- Domenico Azarnia Tehran
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy.
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131 Padova, Italy.
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Caleo M, Restani L. Exploiting Botulinum Neurotoxins for the Study of Brain Physiology and Pathology. Toxins (Basel) 2018; 10:toxins10050175. [PMID: 29693600 PMCID: PMC5983231 DOI: 10.3390/toxins10050175] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 04/21/2018] [Accepted: 04/23/2018] [Indexed: 01/25/2023] Open
Abstract
Botulinum neurotoxins are metalloproteases that specifically cleave N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in synaptic terminals, resulting in a potent inhibition of vesicle fusion and transmitter release. The family comprises different serotypes (BoNT/A to BoNT/G). The natural target of these toxins is represented by the neuromuscular junction, where BoNTs block acetylcholine release. In this review, we describe the actions of botulinum toxins after direct delivery to the central nervous system (CNS), where BoNTs block exocytosis of several transmitters, with near-complete silencing of neural networks. The use of clostridial neurotoxins in the CNS has allowed us to investigate specifically the role of synaptic activity in different physiological and pathological processes. The silencing properties of BoNTs can be exploited for therapeutic purposes, for example to counteract pathological hyperactivity and seizures in epileptogenic brain foci, or to investigate the role of activity in degenerative diseases like prion disease. Altogether, clostridial neurotoxins and their derivatives hold promise as powerful tools for both the basic understanding of brain function and the dissection and treatment of activity-dependent pathogenic pathways.
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Affiliation(s)
- Matteo Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
| | - Laura Restani
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy.
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Pellett S, Bradshaw M, Tepp WH, Pier CL, Whitemarsh RCM, Chen C, Barbieri JT, Johnson EA. The Light Chain Defines the Duration of Action of Botulinum Toxin Serotype A Subtypes. mBio 2018; 9:e00089-18. [PMID: 29588398 PMCID: PMC5874905 DOI: 10.1128/mbio.00089-18] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 12/26/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is the causative agent of botulism and a widely used pharmaceutical to treat a variety of neurological diseases. BoNTs are 150-kDa protein toxins organized into heavy chain (HC) and light chain (LC) domains linked by a disulfide bond. The HC selectively binds to neurons and aids cell entry of the enzymatically active LC. There are seven immunological BoNT serotypes (A to G); each serotype includes genetic variants, termed subtypes. Only two subtypes, BoNT/A1 and BoNT/B1, are currently used as therapeutics. BoNT serotype A (BoNT/A) subtypes A2 to A8 show distinct potency, duration of action, and pathology relative to BoNT/A1. Specifically, BoNT/A3 possesses shorter duration of action and elicits distinct symptoms in mice at high toxin doses. In this report, we analyzed the roles of LC and HC of BoNT/A3 for duration of action, neuronal cell entry, and mouse pathology by using clostridium-derived recombinant hybrid BoNTs consisting of reciprocal LC and HC (BoNTA1/A3 and BoNTA3/A1). Hybrid toxins were processed in their expression host to a dichain BoNT consisting of LC and HC linked via a disulfide bond. The LC and HC defined BoNT potency in mice and BoNT toxicity for cultured neuronal cells, while the LC defined the duration of BoNT action in cell and mouse models. Protein alignment identified a previously unrecognized region within the LC subtype A3 (LC/A3) relative to the other LC serotype A (LC/A) subtypes (low primary acid homology [LPH]) that correlated to intracellular LC localization. This study shows the utility of recombinant hybrid BoNTs with new therapeutic potential, while remaining sensitive to antitoxins and therapies to native BoNT.IMPORTANCE Botulinum neurotoxins are the most potent protein toxins for humans and potential bioterrorism threats, but they are also widely used as pharmaceuticals. Within the large family of BoNTs, only two subtypes are currently used as pharmaceuticals, with a large number of BoNT subtypes remaining as untapped potential sources for unique pharmaceuticals. Here, two recombinant hybrid toxins were engineered, consisting of domains from two BoNT subtypes that possess distinct duration of action and activity in human neurons and mice. We define the functional domains responsible for BoNT action and demonstrate creation of functional hybrid BoNTs with new therapeutic potential, while remaining sensitive to antitoxins and therapies to native BoNT.
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Affiliation(s)
- Sabine Pellett
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Marite Bradshaw
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - William H Tepp
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Christina L Pier
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | | | - Chen Chen
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Joseph T Barbieri
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Eric A Johnson
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
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A Study and Review of Effects of Botulinum Toxins on Mast Cell Dependent and Independent Pruritus. Toxins (Basel) 2018; 10:toxins10040134. [PMID: 29570628 PMCID: PMC5923300 DOI: 10.3390/toxins10040134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/21/2018] [Accepted: 03/21/2018] [Indexed: 12/03/2022] Open
Abstract
Pruriceptive itch originates following activation of peripheral sensory nerve terminals when pruritogens come in contact with the skin. The ability of botulinum neurotoxins (BoNTs) to attenuate transmitter release from afferent terminals provides a rationale for studying its effect on pruritus. This study investigated the effects of BoNT/A1 and BoNT/B1 on mast cell dependent (Compound 48/80:48/80) and independent (Chloroquine:CQ) scratching. C57Bl/6 male mice received intradermal injection of 1.5 U of BoNT/A1, BoNT/B1 or saline 2, 7, 14 and 21 days prior to ipsilateral 48/80 or CQ at the nape of the neck. Ipsilateral hind paw scratching was determined using an automated recording device. The effect of BoNTs on 48/80 mediated mast cell degranulation was analyzed in human and murine mast cells and the presence of SNAREs was determined using qPCR, immunostaining and Western blot. Pre-treatment with BoNT/A1 and BoNT/B1 reduced 48/80 and CQ induced scratching behavior starting on day 2 with reversal by day 21. Both serotypes inhibited 48/80 induced mast cell degranulation. qPCR and immunostaining detected SNAP-25 mRNA and protein, respectively, in mast cells, however, Western blots did not. This study demonstrates the long-lasting anti-pruritic effects of two BoNT serotypes, in a murine pruritus model using two different mechanistically driven pruritogens. These data also indicate that BoNTs may have a direct effect upon mast cell degranulation.
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49
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In vitro assessment of chemotherapy-induced neuronal toxicity. Toxicol In Vitro 2018; 50:109-123. [PMID: 29427706 DOI: 10.1016/j.tiv.2018.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 12/13/2017] [Accepted: 02/06/2018] [Indexed: 12/14/2022]
Abstract
Neurotoxicity is a major concern during drug development, and together with liver and cardio-toxicity, it is one of the main causes of clinical drug attrition. Current pre-clinical models may not sufficiently identify and predict the risk for central or peripheral nervous system toxicity. One such example is clinically dose-limiting neuropathic effects after the administration of chemotherapeutic agents. Thus, the need to establish novel in vitro tools to evaluate the risk of neurotoxicities, such as neuropathy, remains unmet in drug discovery. Though in vitro studies have been conducted using primary and immortalized cell lines, some limitations include the utility for higher throughput methodologies, method reproducibility, and species extrapolation. As a novel alternative, human induced-pluripotent stem cell (iPSC)-derived neurons appear promising for testing new drug candidates. These iPSC-derived neurons are readily available and can be manipulated as required. Here, we describe a novel approach to assess neurotoxicity caused by different classes of chemotherapeutics using kinetic monitoring of neurite dynamic changes and apoptosis in human iPSC-neurons. These studies show promising changes in neurite dynamics in response to clinical inducers of neuropathy, as well as the ability to rank-order and gather mechanistic insight into class-specific compound induced neurotoxicity. This platform can be utilized in early drug development, as part of a weight of evidence approach, to screen drug candidates, and potentially reduce clinical attrition due to neurotoxicity.
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Przedpelski A, Tepp WH, Zuverink M, Johnson EA, Pellet S, Barbieri JT. Enhancing toxin-based vaccines against botulism. Vaccine 2018; 36:827-832. [PMID: 29307477 DOI: 10.1016/j.vaccine.2017.12.064] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 01/25/2023]
Abstract
Botulinum neurotoxins (BoNT) are the most toxic proteins for humans. BoNTs are single chain proteins with an N-terminal light chain (LC) and a C-terminal heavy chain (HC). HC comprises a translocation domain (HCN) and a receptor binding domain (HCC). Currently, there are no approved vaccines against botulism. This study tests a recombinant, full-length BoNT/A1 versus LCHCN/A1 and HCC/A1 as vaccine candidates against botulism. Recombinant, full-length BoNT/A1 was detoxified by engineering 3-amino acid mutations (E224A/R363A/Y366F) (M-BoNT/A1) into the LC to eliminate catalytic activity, which reduced toxicity in a mouse model of botulism by >106-fold relative to native BoNT/A1. As a second step to improve vaccine safety, an additional mutation (W1266A) was engineered in the ganglioside binding pocket, resulting in reduced receptor binding, to produce M-BoNT/A1W. M-BoNT/A1W vaccination protected against challenge by 106 LD50 Units of native BoNT/A1, while M-BoNT/A1 or M-BoNT/A1W vaccination equally protected against challenge by native BoNT/A2, a BoNT subtype. Mice vaccinated with M-BoNT/A1W surviving BoNT challenge had dominant antibody responses to the LCHCN domain, but varied antibody responses to HCC. Sera from mice vaccinated with M-BoNT/A1W also neutralized BoNT/A1 action on cultured neuronal cells. The cell- and mouse-based assays measured different BoNT-neutralizing antibodies, where M-BoNT/A1W elicited a strong neutralizing response in both assays. Overall, M-BoNT/A1W, with defects in multiple toxin functions, elicits a potent immune response to BoNT/A challenge as a vaccine strategy against botulism and other toxin-mediated diseases.
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Affiliation(s)
- Amanda Przedpelski
- Medical College of Wisconsin, 8701 W Watertown Plank Rd., Microbiology and Immunology, Milwaukee, WI 53226, United States
| | - William H Tepp
- University of Wisconsin-Madison, 6303 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706, United States
| | - Madison Zuverink
- Medical College of Wisconsin, 8701 W Watertown Plank Rd., Microbiology and Immunology, Milwaukee, WI 53226, United States
| | - Eric A Johnson
- University of Wisconsin-Madison, 6303 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706, United States
| | - Sabine Pellet
- University of Wisconsin-Madison, 6303 Microbial Sciences Building, 1550 Linden Dr., Madison, WI 53706, United States
| | - Joseph T Barbieri
- Medical College of Wisconsin, 8701 W Watertown Plank Rd., Microbiology and Immunology, Milwaukee, WI 53226, United States.
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