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Rasetti-Escargueil C, Palea S. Embracing the Versatility of Botulinum Neurotoxins in Conventional and New Therapeutic Applications. Toxins (Basel) 2024; 16:261. [PMID: 38922155 PMCID: PMC11209287 DOI: 10.3390/toxins16060261] [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: 04/15/2024] [Revised: 05/26/2024] [Accepted: 05/27/2024] [Indexed: 06/27/2024] Open
Abstract
Botulinum neurotoxins (BoNTs) have been used for almost half a century in the treatment of excessive muscle contractility. BoNTs are routinely used to treat movement disorders such as cervical dystonia, spastic conditions, blepharospasm, and hyperhidrosis, as well as for cosmetic purposes. In addition to the conventional indications, the use of BoNTs to reduce pain has gained increased recognition, giving rise to an increasing number of indications in disorders associated with chronic pain. Furthermore, BoNT-derived formulations are benefiting a much wider range of patients suffering from overactive bladder, erectile dysfunction, arthropathy, neuropathic pain, and cancer. BoNTs are categorised into seven toxinotypes, two of which are in clinical use, and each toxinotype is divided into multiple subtypes. With the development of bioinformatic tools, new BoNT-like toxins have been identified in non-Clostridial organisms. In addition to the expanding indications of existing formulations, the rich variety of toxinotypes or subtypes in the wild-type BoNTs associated with new BoNT-like toxins expand the BoNT superfamily, forming the basis on which to develop new BoNT-based therapeutics as well as research tools. An overview of the diversity of the BoNT family along with their conventional therapeutic uses is presented in this review followed by the engineering and formulation opportunities opening avenues in therapy.
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Affiliation(s)
| | - Stefano Palea
- Humana Biosciences-Prologue Biotech, 516 Rue Pierre et Marie Curie, 31670 Labège, France;
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2
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Gregg BM, Matsumura T, Wentz TG, Tepp WH, Bradshaw M, Stenmark P, Johnson EA, Fujinaga Y, Pellett S. Botulinum neurotoxin X lacks potency in mice and in human neurons. mBio 2024; 15:e0310623. [PMID: 38347673 PMCID: PMC10936432 DOI: 10.1128/mbio.03106-23] [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: 11/15/2023] [Accepted: 01/16/2024] [Indexed: 03/14/2024] Open
Abstract
Botulinum neurotoxins (BoNTs) are a class of toxins produced by Clostridium botulinum (C. botulinum) and other species of Clostridia. BoNT/X is a putative novel botulinum neurotoxin identified through genome sequencing and capable of SNARE cleavage, but its neurotoxic potential in humans and vertebrates remained unclear. The C. botulinum strain producing BoNT/X, Strain 111, encodes both a plasmid-borne bont/b2 as well as the chromosomal putative bont/x. This study utilized C. botulinum Strain 111 from Japan as well as recombinantly produced full-length BoNT/X to more fully analyze this putative pathogenic toxin. We confirmed production of full-length, catalytically active native BoNT/X by C. botulinum Strain 111, produced as a disulfide-bonded dichain polypeptide similar to other BoNTs. Both the purified native and the recombinant BoNT/X had high enzymatic activity in vitro but displayed very low potency in human-induced pluripotent stem cell-derived neuronal cells and in mice. Intraperitoneal injection of up to 50 µg of native BoNT/X in mice did not result in botulism; however, mild local paralysis was observed after injection of 2 μg into the gastrocnemius muscle. We further demonstrate that the lack of toxicity by BoNT/X is due to inefficient neuronal cell association and entry, which can be rescued by replacing the receptor binding domain of BoNT/X with that of BoNT/A. These data demonstrate that BoNT/X is not a potent vertebrate neurotoxin like the classical seven serotypes of BoNTs. IMPORTANCE The family of botulinum neurotoxins comprises the most potent toxins known to humankind. New members of this family of protein toxins as well as more distantly related homologs are being identified. The discovery of BoNT/X via bioinformatic screen in 2017 as a putative new BoNT serotype raised concern about its potential as a pathogenic agent with no available countermeasures. This study for the first time assessed both recombinantly produced and native purified BoNT/X for its vertebrate neurotoxicity.
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Affiliation(s)
- Brieana M. Gregg
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Takuhiro Matsumura
- Department of Bacteriology, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Travis G. Wentz
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - William H. Tepp
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Marite Bradshaw
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Eric A. Johnson
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Yukako Fujinaga
- Department of Bacteriology, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
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3
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Košenina S, Škerlová J, Zhang S, Dong M, Stenmark P. The cryo-EM structure of the BoNT/Wo-NTNH complex reveals two immunoglobulin-like domains. FEBS J 2024; 291:676-689. [PMID: 37746829 DOI: 10.1111/febs.16964] [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: 07/03/2023] [Revised: 09/07/2023] [Accepted: 09/20/2023] [Indexed: 09/26/2023]
Abstract
The botulinum neurotoxin-like toxin from Weissella oryzae (BoNT/Wo) is one of the BoNT-like toxins recently identified outside of the Clostridium genus. We show that, like the canonical BoNTs, BoNT/Wo forms a complex with its non-toxic non-hemagglutinin (NTNH) partner, which in traditional BoNT serotypes protects the toxin from proteases and the acidic environment of the hosts' guts. We here report the cryo-EM structure of the 300 kDa BoNT/Wo-NTNH/Wo complex together with pH stability studies of the complex. The structure reveals molecular details of the toxin's interactions with its protective partner. The overall structural arrangement is similar to other reported BoNT-NTNH complexes, but NTNH/Wo uniquely contains two extra bacterial immunoglobulin-like (Big) domains on the C-terminus. Although the function of these Big domains is unknown, they are structurally most similar to bacterial proteins involved in adhesion to host cells. In addition, the BoNT/Wo protease domain contains an internal disulfide bond not seen in other BoNTs. Mass photometry analysis revealed that the BoNT/Wo-NTNH/Wo complex is stable under acidic conditions and may dissociate at neutral to basic pH. These findings established that BoNT/Wo-NTNH/Wo shares the general fold of canonical BoNT-NTNH complexes. The presence of unique structural features suggests that it may have an alternative mode of activation, translocation and recognition of host cells, raising interesting questions about the activity and the mechanism of action of BoNT/Wo as well as about its target environment, receptors and substrates.
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Affiliation(s)
- Sara Košenina
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Jana Škerlová
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, MA, USA
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
- Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, 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, Sweden
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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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Smith TJ, Schill KM, Williamson CHD. Navigating the Complexities Involving the Identification of Botulinum Neurotoxins (BoNTs) and the Taxonomy of BoNT-Producing Clostridia. Toxins (Basel) 2023; 15:545. [PMID: 37755971 PMCID: PMC10535752 DOI: 10.3390/toxins15090545] [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: 06/09/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 09/28/2023] Open
Abstract
Botulinum neurotoxins are a varied group of protein toxins that share similar structures and modes of activity. They include at least seven serotypes and over forty subtypes that are produced by seven different clostridial species. These bacterial species are not limited strictly to BoNT-producers as neuro-toxigenic and non-neuro-toxigenic members have been identified within each species. The nomenclature surrounding these toxins and associated bacteria has been evolving as new isolations and discoveries have arisen, resulting in challenges in diagnostic reporting, epidemiology and food safety studies, and in the application of therapeutic products. An understanding of the intricacies regarding the nomenclature of BoNTs and BoNT-producing clostridia is crucial for communication that allows for accurate reporting of information that is pertinent to each situation.
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Affiliation(s)
- Theresa J. Smith
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA;
| | - Kristin M. Schill
- Food Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA;
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Intiso D, Centra AM, Gravina M, Chiaramonte A, Bartolo M, Di Rienzo F. Botulinum Toxin-A High-Dosage Effect on Functional Outcome and Spasticity-Related Pain in Subjects with Stroke. Toxins (Basel) 2023; 15:509. [PMID: 37624266 PMCID: PMC10467116 DOI: 10.3390/toxins15080509] [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: 06/29/2023] [Revised: 08/08/2023] [Accepted: 08/14/2023] [Indexed: 08/26/2023] Open
Abstract
Stroke patients can develop spasticity and spasticity-related pain (SRP). These disorders are frequent and can contribute to functional limitations and disabling conditions. Many reports have suggested that higher doses than initially recommended of BTX-A can be used effectively and safely, especially in the case of severe spasticity; however, whether the treatment produces any benefit on the functional outcome and SRP is unclear. Studies published between January 1989 and December 2022 were retrieved from MEDLINE/PubMed, Embase, and Cochrane Central Register. Only obabotulinumtoxinA (obaBTX-A), onabotulinumtoxinA, (onaBTX-A), and incobotulinumtoxinA (incoBTX-A) were considered. The term "high dosage" indicates ≥600 U. Nine studies met the inclusion criteria. Globally, 460 subjects were treated with BTX-A high dose, and 301 suffered from stroke. Studies had variable method designs, sample sizes, and aims. Only five (55.5%) reported data about the functional outcome after BTX-A injection. Functional measures were also variable, and the improvement was observed predominantly in the disability assessment scale (DAS). SRP pain was quantified by visual analog scale (VAS) and only three studies reported the BTX-A effect. There is no scientific evidence that this therapeutic strategy unequivocally improves the functionality of the limbs. Although no clear-cut evidence emerges, certain patients with spasticity might obtain goal-oriented improvement from high-dose BTX-A. Likewise, data are insufficient to recommend high BTX dosage in SRP.
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Affiliation(s)
- Domenico Intiso
- Unit of Neuro-Rehabilitation Unit and Rehabilitation Medicine, IRCCS ‘Casa Sollievo della Sofferenza’, Viale dei Cappuccini 1, San Giovanni Rotondo, 71013 Foggia, Italy; (A.M.C.); (M.G.); (A.C.); (F.D.R.)
| | - Antonello Marco Centra
- Unit of Neuro-Rehabilitation Unit and Rehabilitation Medicine, IRCCS ‘Casa Sollievo della Sofferenza’, Viale dei Cappuccini 1, San Giovanni Rotondo, 71013 Foggia, Italy; (A.M.C.); (M.G.); (A.C.); (F.D.R.)
| | - Michele Gravina
- Unit of Neuro-Rehabilitation Unit and Rehabilitation Medicine, IRCCS ‘Casa Sollievo della Sofferenza’, Viale dei Cappuccini 1, San Giovanni Rotondo, 71013 Foggia, Italy; (A.M.C.); (M.G.); (A.C.); (F.D.R.)
| | - Angelo Chiaramonte
- Unit of Neuro-Rehabilitation Unit and Rehabilitation Medicine, IRCCS ‘Casa Sollievo della Sofferenza’, Viale dei Cappuccini 1, San Giovanni Rotondo, 71013 Foggia, Italy; (A.M.C.); (M.G.); (A.C.); (F.D.R.)
| | - Michelangelo Bartolo
- Department of Rehabilitation, Neurorehabilitation Unit, HABILITA Zingonia, Ciserano, 24040 Bergamo, Italy;
| | - Filomena Di Rienzo
- Unit of Neuro-Rehabilitation Unit and Rehabilitation Medicine, IRCCS ‘Casa Sollievo della Sofferenza’, Viale dei Cappuccini 1, San Giovanni Rotondo, 71013 Foggia, Italy; (A.M.C.); (M.G.); (A.C.); (F.D.R.)
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7
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Fan Y, Lou J, Tam CC, Wen W, Conrad F, Leal da Silva Alves P, Cheng LW, Garcia-Rodriguez C, Farr-Jones S, Marks JD. A Three-Monoclonal Antibody Combination Potently Neutralizes BoNT/G Toxin in Mice. Toxins (Basel) 2023; 15:toxins15050316. [PMID: 37235351 DOI: 10.3390/toxins15050316] [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: 02/25/2023] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Equine-derived antitoxin (BAT®) is the only treatment for botulism from botulinum neurotoxin serotype G (BoNT/G). BAT® is a foreign protein with potentially severe adverse effects and is not renewable. To develop a safe, more potent, and renewable antitoxin, humanized monoclonal antibodies (mAbs) were generated. Yeast displayed single chain Fv (scFv) libraries were prepared from mice immunized with BoNT/G and BoNT/G domains and screened with BoNT/G using fluorescence-activated cell sorting (FACS). Fourteen scFv-binding BoNT/G were isolated with KD values ranging from 3.86 nM to 103 nM (median KD 20.9 nM). Five mAb-binding non-overlapping epitopes were humanized and affinity matured to create antibodies hu6G6.2, hu6G7.2, hu6G9.1, hu6G10, and hu6G11.2, with IgG KD values ranging from 51 pM to 8 pM. Three IgG combinations completely protected mice challenged with 10,000 LD50s of BoNT/G at a total mAb dose of 6.25 μg per mouse. The mAb combinations have the potential for use in the diagnosis and treatment of botulism due to serotype G and, along with antibody combinations to BoNT/A, B, C, D, E, and F, provide the basis for a fully recombinant heptavalent botulinum antitoxin to replace the legacy equine product.
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Affiliation(s)
- Yongfeng Fan
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - Jianlong Lou
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - Christina C Tam
- Western Regional Research Center, Agricultural Research Station, United States Department of Agriculture, Albany, CA 94710, USA
| | - Weihua Wen
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - Fraser Conrad
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - Priscila Leal da Silva Alves
- Western Regional Research Center, Agricultural Research Station, United States Department of Agriculture, Albany, CA 94710, USA
| | - Luisa W Cheng
- Western Regional Research Center, Agricultural Research Station, United States Department of Agriculture, Albany, CA 94710, USA
| | - Consuelo Garcia-Rodriguez
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - Shauna Farr-Jones
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, USA
| | - James D Marks
- Department of Anesthesia and Perioperative Care, University of California, 1001 Potrero Ave., San Francisco, CA 94110, 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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Peñuelas M, Guerrero-Vadillo M, Valdezate S, Zamora MJ, Leon-Gomez I, Flores-Cuéllar Á, Carrasco G, Díaz-García O, Varela C. Botulism in Spain: Epidemiology and Outcomes of Antitoxin Treatment, 1997-2019. Toxins (Basel) 2022; 15:2. [PMID: 36668823 PMCID: PMC9863742 DOI: 10.3390/toxins15010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Botulism is a low incidence but potentially fatal infectious disease caused by neurotoxins produced mainly by Clostridium botulinum. There are different routes of acquisition, food-borne and infant/intestinal being the most frequent presentation, and antitoxin is the treatment of choice in all cases. In Spain, botulism is under surveillance, and case reporting is mandatory. METHODS This retrospective study attempts to provide a more complete picture of the epidemiology of botulism in Spain from 1997 to 2019 and an assessment of the treatment, including the relationship between a delay in antitoxin administration and the length of hospitalization using the Cox proportional hazards test and Kruskal-Wallis test, and an approach to the frequency of adverse events, issues for which no previous national data have been published. RESULTS Eight of the 44 outbreaks were associated with contaminated commercial foods involving ≤7 cases/outbreak; preserved vegetables were the main source of infection, followed by fish products; early antitoxin administration significantly reduces the hospital stay, and adverse reactions to the antitoxin affect around 3% of treated cases.
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Affiliation(s)
- Marina Peñuelas
- Escuela Internacional de Doctorado, Universidad Nacional de Educación a Distancia (UNED), Calle de Bravo Murillo, 38, 28015 Madrid, Spain
- Department of Communicable Diseases, National Centre of Epidemiology, Instituto de Salud Carlos III, C/Monforte de Lemos 5, Pabellón 12, 28029 Madrid, Spain
| | - María Guerrero-Vadillo
- Department of Communicable Diseases, National Centre of Epidemiology, Instituto de Salud Carlos III, C/Monforte de Lemos 5, Pabellón 12, 28029 Madrid, Spain
| | - Sylvia Valdezate
- Laboratorio de Referencia e Investigación en Taxonomía, Bacteriología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera Pozuelo-Majadahonda Km 2.2, 28220 Madrid, Spain
| | - María Jesús Zamora
- Servicio de Microbiología Alimentaria, Centro Nacional de Alimentación, Agencia Española de Seguridad Alimentaria y Nutrición, Ctra. Pozuelo a Majadahonda Km 5.1, 28220 Madrid, Spain
| | - Inmaculada Leon-Gomez
- Department of Communicable Diseases, National Centre of Epidemiology, Instituto de Salud Carlos III, C/Monforte de Lemos 5, Pabellón 12, 28029 Madrid, Spain
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), 28029 Madrid, Spain
| | - Ángeles Flores-Cuéllar
- Medicines for Human Use Department, Agencia Española de Medicamentos y Productos Sanitarios (AEMPS), C/Campezo 1, Edificio 8, 28022 Madrid, Spain
| | - Gema Carrasco
- Laboratorio de Referencia e Investigación en Taxonomía, Bacteriología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Carretera Pozuelo-Majadahonda Km 2.2, 28220 Madrid, Spain
| | - Oliva Díaz-García
- Department of Communicable Diseases, National Centre of Epidemiology, Instituto de Salud Carlos III, C/Monforte de Lemos 5, Pabellón 12, 28029 Madrid, Spain
| | - Carmen Varela
- Department of Communicable Diseases, National Centre of Epidemiology, Instituto de Salud Carlos III, C/Monforte de Lemos 5, Pabellón 12, 28029 Madrid, Spain
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), 28029 Madrid, Spain
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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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11
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Cleveland JD, Taslimi A, Liu Q, Van Keuren AM, Churchill MEA, Tucker CL. Reprogramming the Cleavage Specificity of Botulinum Neurotoxin Serotype B1. ACS Synth Biol 2022; 11:3318-3329. [PMID: 36153971 PMCID: PMC9907380 DOI: 10.1021/acssynbio.2c00235] [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] [Indexed: 01/24/2023]
Abstract
Proteases with reprogrammed specificity for nonnative substrates are highly desired in synthetic biology and biomedicine. However, generating reprogrammed proteases that are orthogonal and highly specific for a new target has been a major challenge. In this work, we sought to expand the versatility of protease systems by engineering an orthogonal botulinum neurotoxin serotype B (BoNT/B) protease that recognizes an orthogonal substrate. We designed and validated an orthogonal BoNT/B protease system in mammalian cells, combining mutations in the protease with compensatory mutations in the protease substrate and incorporating a truncated target sequence and then demonstrated use of this orthogonal BoNT/B protease-substrate combination to regulate complex transcriptional circuitry in mammalian cells. Transposing this platform into yeast, we demonstrated utility of this approach for in vivo protease evolution. We tested this platform with the newly designed orthogonal protease and then used it in a high-throughput screen to identify novel orthogonal protease/protease substrate combinations. While carrying out this work, we also generated new cleavage reporters that could be used to report botulinum toxin protease activity in mammalian cells using simple fluorescent readouts. We envision that these approaches will expand the applications of botulinum protease in new directions and aid in the development of new reprogrammed proteases.
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Affiliation(s)
- Joseph D. Cleveland
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
| | - Amir Taslimi
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
| | - Qi Liu
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
| | - Anna M. Van Keuren
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
| | - Mair E. A. Churchill
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
| | - Chandra L. Tucker
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045 USA
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12
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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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13
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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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14
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Regulatory Networks Controlling Neurotoxin Synthesis in Clostridium botulinum and Clostridium tetani. Toxins (Basel) 2022; 14:toxins14060364. [PMID: 35737025 PMCID: PMC9229411 DOI: 10.3390/toxins14060364] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/16/2022] [Accepted: 05/21/2022] [Indexed: 12/30/2022] Open
Abstract
Clostridium botulinum and Clostridium tetani are Gram-positive, spore-forming, and anaerobic bacteria that produce the most potent neurotoxins, botulinum toxin (BoNT) and tetanus toxin (TeNT), responsible for flaccid and spastic paralysis, respectively. The main habitat of these toxigenic bacteria is the environment (soil, sediments, cadavers, decayed plants, intestinal content of healthy carrier animals). C. botulinum can grow and produce BoNT in food, leading to food-borne botulism, and in some circumstances, C. botulinum can colonize the intestinal tract and induce infant botulism or adult intestinal toxemia botulism. More rarely, C. botulinum colonizes wounds, whereas tetanus is always a result of wound contamination by C. tetani. The synthesis of neurotoxins is strictly regulated by complex regulatory networks. The highest levels of neurotoxins are produced at the end of the exponential growth and in the early stationary growth phase. Both microorganisms, except C. botulinum E, share an alternative sigma factor, BotR and TetR, respectively, the genes of which are located upstream of the neurotoxin genes. These factors are essential for neurotoxin gene expression. C. botulinum and C. tetani share also a two-component system (TCS) that negatively regulates neurotoxin synthesis, but each microorganism uses additional distinct sets of TCSs. Neurotoxin synthesis is interlocked with the general metabolism, and CodY, a master regulator of metabolism in Gram-positive bacteria, is involved in both clostridial species. The environmental and nutritional factors controlling neurotoxin synthesis are still poorly understood. The transition from amino acid to peptide metabolism seems to be an important factor. Moreover, a small non-coding RNA in C. tetani, and quorum-sensing systems in C. botulinum and possibly in C. tetani, also control toxin synthesis. However, both species use also distinct regulatory pathways; this reflects the adaptation of C. botulinum and C. tetani to different ecological niches.
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15
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Rasetti-Escargueil C, Popoff MR. Recent Developments in Botulinum Neurotoxins Detection. Microorganisms 2022; 10:microorganisms10051001. [PMID: 35630444 PMCID: PMC9145529 DOI: 10.3390/microorganisms10051001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/29/2022] [Accepted: 05/03/2022] [Indexed: 02/04/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are produced as protein complexes by bacteria of the genus Clostridium that are Gram-positive, anaerobic and spore forming (Clostridium botulinum, C. butyricum, C. baratii and C. argentinense spp.). BoNTs show a high immunological and genetic diversity. Therefore, fast, precise, and more reliable detection methods are still required to monitor outbreaks and ensure surveillance of botulism. The botulinum toxin field also comprises therapeutic uses, basic research studies and biodefense issues. This review presents currently available detection methods, and new methods offering the potential of enhanced precision and reproducibility. While the immunological methods offer a range of benefits, such as rapid analysis time, reproducibility and high sensitivity, their implementation is subject to the availability of suitable tools and reagents, such as specific antibodies. Currently, the mass spectrometry approach is the most sensitive in vitro method for a rapid detection of active or inactive forms of BoNTs. However, these methods require inter-laboratory validation before they can be more widely implemented in reference laboratories. In addition, these surrogate in vitro models also require full validation before they can be used as replacement bioassays of potency. Cell-based assays using neuronal cells in culture recapitulate all functional steps of toxin activity, but are still at various stages of development; they are not yet sufficiently robust, due to high batch-to-batch cell variability. Cell-based assays have a strong potential to replace the mouse bioassay (MBA) in terms of BoNT potency determination in pharmaceutical formulations; they can also help to identify suitable inhibitors while reducing the number of animals used. However, the development of safe countermeasures still requires the use of in vivo studies to complement in vitro immunological or cell-based approaches.
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16
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Pirazzini M, Montecucco C, Rossetto O. Toxicology and pharmacology of botulinum and tetanus neurotoxins: an update. Arch Toxicol 2022; 96:1521-1539. [PMID: 35333944 PMCID: PMC9095541 DOI: 10.1007/s00204-022-03271-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 02/28/2022] [Indexed: 12/27/2022]
Abstract
Tetanus and botulinum neurotoxins cause the neuroparalytic syndromes of tetanus and botulism, respectively, by delivering inside different types of neurons, metalloproteases specifically cleaving the SNARE proteins that are essential for the release of neurotransmitters. Research on their mechanism of action is intensively carried out in order to devise improved therapies based on antibodies and chemical drugs. Recently, major results have been obtained with human monoclonal antibodies and with single chain antibodies that have allowed one to neutralize the metalloprotease activity of botulinum neurotoxin type A1 inside neurons. In addition, a method has been devised to induce a rapid molecular evolution of the metalloprotease domain of botulinum neurotoxin followed by selection driven to re-target the metalloprotease activity versus novel targets with respect to the SNARE proteins. At the same time, an intense and wide spectrum clinical research on novel therapeutics based on botulinum neurotoxins is carried out, which are also reviewed here.
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Affiliation(s)
- Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy.,Centro Interdipartimentale di Ricerca di Miologia, CIR-Myo, University of Padova, Via U. Bassi 58/B, 35131, Padova, Italy
| | - Cesare Montecucco
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy. .,Institute of Neuroscience, National Research Council, Via Ugo Bassi 58/B, 35131, Padova, Italy.
| | - Ornella Rossetto
- Department of Biomedical Sciences, University of Padova, Via Ugo Bassi 58/B, 35131, Padova, Italy.,Centro Interdipartimentale di Ricerca di Miologia, CIR-Myo, University of Padova, Via U. Bassi 58/B, 35131, Padova, Italy.,Institute of Neuroscience, National Research Council, Via Ugo Bassi 58/B, 35131, Padova, Italy
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17
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Dilena R, Pozzato M, Baselli L, Chidini G, Barbieri S, Scalfaro C, Finazzi G, Lonati D, Locatelli CA, Cappellari A, Anniballi F. Infant Botulism: Checklist for Timely Clinical Diagnosis and New Possible Risk Factors Originated from a Case Report and Literature Review. Toxins (Basel) 2021; 13:toxins13120860. [PMID: 34941698 PMCID: PMC8703831 DOI: 10.3390/toxins13120860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 12/24/2022] Open
Abstract
Infant botulism is a rare and underdiagnosed disease caused by BoNT-producing clostridia that can temporarily colonize the intestinal lumen of infants less than one year of age. The diagnosis may be challenging because of its rareness, especially in patients showing atypical presentations or concomitant coinfections. In this paper, we report the first infant botulism case associated with Cytomegalovirus coinfection and transient hypogammaglobulinemia and discuss the meaning of these associations in terms of risk factors. Intending to help physicians perform the diagnosis, we also propose a practical clinical and diagnostic criteria checklist based on the revision of the literature.
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Affiliation(s)
- Robertino Dilena
- Unità di Neurofiopatologia, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (S.B.); (A.C.)
- Correspondence:
| | - Mattia Pozzato
- Neurology Unit & MS Centre, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation, University of Milan, 20122 Milan, Italy
| | - Lucia Baselli
- Pediatric Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Giovanna Chidini
- Pediatric Intensive Care Unit, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy;
| | - Sergio Barbieri
- Unità di Neurofiopatologia, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (S.B.); (A.C.)
| | - Concetta Scalfaro
- National Reference Centre for Botulism, Nutrition and Veterinary Public Health, Department of Food Safety, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.S.); (F.A.)
| | - Guido Finazzi
- Department of Food Control, Istituto Zooprofilattico Sperimentale della Lombardia e dell’Emilia-Romagna, 25124 Brescia, Italy;
| | - Davide Lonati
- Toxicology Unit, Laboratory of Clinical and Experimental Toxicology, and Poison Control Centre and National Toxicology Information Centre, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy; (D.L.); (C.A.L.)
| | - Carlo Alessandro Locatelli
- Toxicology Unit, Laboratory of Clinical and Experimental Toxicology, and Poison Control Centre and National Toxicology Information Centre, Istituti Clinici Scientifici Maugeri IRCCS, 27100 Pavia, Italy; (D.L.); (C.A.L.)
| | - Alberto Cappellari
- Unità di Neurofiopatologia, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy; (S.B.); (A.C.)
| | - Fabrizio Anniballi
- National Reference Centre for Botulism, Nutrition and Veterinary Public Health, Department of Food Safety, Istituto Superiore di Sanità, 00161 Rome, Italy; (C.S.); (F.A.)
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18
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Hong JY, Kim JH, Jin JE, Shin SH, Park KY. Practical Application of Novel Test Methods to Evaluate the Potency of Botulinum Toxin: A Comparison Analysis among Widely Used Products in Korea. Toxins (Basel) 2021; 13:toxins13120833. [PMID: 34941671 PMCID: PMC8707463 DOI: 10.3390/toxins13120833] [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: 10/15/2021] [Revised: 11/18/2021] [Accepted: 11/22/2021] [Indexed: 11/29/2022] Open
Abstract
The safe and effective dosing of botulinum neurotoxins (BoNTs) requires accurate and reliable methods to measure their potency. Several novel methods have been introduced over the past decade; however, only few studies have compared the potency of BoNT products with that of the LD50 and other alternative assays. Therefore, the objective of this study was to comparatively evaluate widely used BoNT products using various test methods. Four types of BoNTs (prabotulinumtoxin A, onabotulinumtoxin A, neubotulinumtoxin A, and letibotulinumtoxin A) were used in this study. The estimated potency was assessed using the LD50 assay, and the total BoNT type A protein levels were measured using the enzyme-linked immunosorbent assay (ELISA). The in vitro efficacy of the BoNTs was determined using fluorescence resonance energy transfer (FRET) and surface plasmon resonance (SPR) assays. The results showed differences in the total amount of BoNT protein and the cleavage activity of SNAP-25 within all types of BoNTs. The SPR study seemed to be useful for evaluating the potency by specifically measuring intact 19S neurotoxin, and these results provide new insights for assessing different BoNT products.
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Affiliation(s)
- Ji-Yeon Hong
- Department of Dermatology, Chungnam National University Sejong Hospital, Sejong 30099, Korea;
| | - Jong-Hee Kim
- NABOTA Research and Development Team, Daewoong Pharmaceuticals, Seoul 06973, Korea; (J.-H.K.); (J.-E.J.)
| | - Jung-Eun Jin
- NABOTA Research and Development Team, Daewoong Pharmaceuticals, Seoul 06973, Korea; (J.-H.K.); (J.-E.J.)
| | - Sun-Hye Shin
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 06973, Korea;
| | - Kui-Young Park
- Department of Dermatology, College of Medicine, Chung-Ang University, Seoul 06973, Korea;
- Correspondence: ; Tel.: +82-2-6299-1544; Fax: +82-2-6299-1718
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19
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Cai S, Kumar R, Singh BR. Clostridial Neurotoxins: Structure, Function and Implications to Other Bacterial Toxins. Microorganisms 2021; 9:2206. [PMID: 34835332 PMCID: PMC8618262 DOI: 10.3390/microorganisms9112206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 01/20/2023] Open
Abstract
Gram-positive bacteria are ancient organisms. Many bacteria, including Gram-positive bacteria, produce toxins to manipulate the host, leading to various diseases. While the targets of Gram-positive bacterial toxins are diverse, many of those toxins use a similar mechanism to invade host cells and exert their functions. Clostridial neurotoxins produced by Clostridial tetani and Clostridial botulinum provide a classical example to illustrate the structure-function relationship of bacterial toxins. Here, we critically review the recent progress of the structure-function relationship of clostridial neurotoxins, including the diversity of the clostridial neurotoxins, the mode of actions, and the flexible structures required for the activation of toxins. The mechanism clostridial neurotoxins use for triggering their activity is shared with many other Gram-positive bacterial toxins, especially molten globule-type structures. This review also summarizes the implications of the molten globule-type flexible structures to other Gram-positive bacterial toxins. Understanding these highly dynamic flexible structures in solution and their role in the function of bacterial toxins not only fills in the missing link of the high-resolution structures from X-ray crystallography but also provides vital information for better designing antidotes against those toxins.
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Affiliation(s)
- Shuowei Cai
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA 02747, USA
| | - Raj Kumar
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA; (R.K.); (B.R.S.)
| | - Bal Ram Singh
- Botulinum Research Center, Institute of Advanced Sciences, Dartmouth, MA 02747, USA; (R.K.); (B.R.S.)
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20
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Current Developments in Diagnostic Assays for Laboratory Confirmation and Investigation of Botulism. J Clin Microbiol 2021; 60:e0013920. [PMID: 34586891 DOI: 10.1128/jcm.00139-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Detection of botulinum neurotoxin or isolation of the toxin producing organism is required for the laboratory confirmation of botulism in clinical specimens. In an effort to reduce animal testing required by the gold standard method of botulinum neurotoxin detection, the mouse bioassay, many technologies have been developed to detect and characterize the causative agent of botulism. Recent advancements in these technologies have led to improvements in technical performance of diagnostic assays; however, many emerging assays have not been validated for the detection of all serotypes in complex clinical and environmental matrices. Improvements to culture protocols, endopeptidase-based assays, and a variety of immunological and molecular methods have provided laboratories with a variety of testing options to evaluate and incorporate into their testing algorithms. While significant advances have been made to improve these assays, additional work is necessary to evaluate these methods in various clinical matrices and to establish standardized criteria for data analysis and interpretation.
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21
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Antonucci L, Locci C, Schettini L, Clemente MG, Antonucci R. Infant botulism: an underestimated threat. Infect Dis (Lond) 2021; 53:647-660. [PMID: 33966588 DOI: 10.1080/23744235.2021.1919753] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Infant botulism (IB) is defined as a potentially life-threatening neuroparalytic disorder affecting children younger than 12 months. It is caused by ingestion of food or dust contaminated by Clostridium botulinum spores, which germinate in the infant's large bowel and produce botulinum neurotoxin. Although the real impact of IB is likely underestimated worldwide, the USA has the highest number of cases. The limited reporting of IB in many countries is probably due to diagnostic difficulties and nonspecific presentation. The onset is usually heralded by constipation, followed by bulbar palsy, and then by a descending bilateral symmetric paralysis; ultimately, palsy can involve respiratory and diaphragmatic muscles, leading to respiratory failure. The treatment is based on supportive care and specific therapy with Human Botulism Immune Globulin Intravenous (BIG-IV), and should be started as early as possible. The search for new human-like antibody preparations that are both highly effective and well tolerated has led to the creation of a mixture of oligoclonal antibodies that are highly protective and can be produced in large quantities without the use of animals. Ongoing research for future treatment of IB involves the search for new molecular targets to produce a new generation of laboratory-produced antitoxins, and the development of new vaccines with safety and efficacy profiles that can be scaled up for clinical use. This narrative literature review aims to provide a readable synthesis of the best current literature on microbiological, epidemiological and clinical features of IB, and a practical guide for its treatment.
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Affiliation(s)
- Luca Antonucci
- Academic Department of Pediatrics, Children's Hospital Bambino Gesù, University of Rome 'Tor Vergata', Rome, Italy
| | - Cristian Locci
- Pediatric Clinic, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
| | - Livia Schettini
- Academic Department of Pediatrics, Children's Hospital Bambino Gesù, University of Rome 'Tor Vergata', Rome, Italy
| | - Maria Grazia Clemente
- Pediatric Clinic, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
| | - Roberto Antonucci
- Pediatric Clinic, Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
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22
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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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Choudhury S, Baker MR, Chatterjee S, Kumar H. Botulinum Toxin: An Update on Pharmacology and Newer Products in Development. Toxins (Basel) 2021; 13:58. [PMID: 33466571 PMCID: PMC7828686 DOI: 10.3390/toxins13010058] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/12/2022] Open
Abstract
Since its introduction as a treatment for strabismus, botulinum toxin (BoNT) has had a phenomenal journey and is now recommended as first-line treatment for focal dystonia, despite short-term clinical benefits and the risks of adverse effects. To cater for the high demand across various medical specialties, at least six US Food and Drug Administration (FDA)-approved formulations of BoNT are currently available for diverse labelled indications. The toxo-pharmacological properties of these formulations are not uniform and thus should not be used interchangeably. Synthetic BoNTs and BoNTs from non-clostridial sources are not far from clinical use. Moreover, the study of mutations in naturally occurring toxins has led to modulation in the toxo-pharmacokinetic properties of BoNTs, including the duration and potency. We present an overview of the toxo-pharmacology of conventional and novel BoNT preparations, including those awaiting imminent translation from the laboratory to the clinic.
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Affiliation(s)
- Supriyo Choudhury
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
| | - Mark R. Baker
- Departments of Neurology and Clinical Neurophysiology, Royal Victoria Infirmary, Queen Victoria Rd, Newcastle upon Tyne NE1 4LP, UK;
- Translational and Clinical Research Institute, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Suparna Chatterjee
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
- Department of Pharmacology, Institute of Post Graduate Medical Education and Research, Kolkata 700020, India
| | - Hrishikesh Kumar
- Department of Neurology, Institute of Neurosciences Kolkata, Kolkata 700017, India; (S.C.); (S.C.)
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Harnessing the Membrane Translocation Properties of AB Toxins for Therapeutic Applications. Toxins (Basel) 2021; 13:toxins13010036. [PMID: 33418946 PMCID: PMC7825107 DOI: 10.3390/toxins13010036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/28/2020] [Accepted: 01/01/2021] [Indexed: 12/31/2022] Open
Abstract
Over the last few decades, proteins and peptides have become increasingly more common as FDA-approved drugs, despite their inefficient delivery due to their inability to cross the plasma membrane. In this context, bacterial two-component systems, termed AB toxins, use various protein-based membrane translocation mechanisms to deliver toxins into cells, and these mechanisms could provide new insights into the development of bio-based drug delivery systems. These toxins have great potential as therapies both because of their intrinsic properties as well as the modular characteristics of both subunits, which make them highly amenable to conjugation with various drug classes. This review focuses on the therapeutical approaches involving the internalization mechanisms of three representative AB toxins: botulinum toxin type A, anthrax toxin, and cholera toxin. We showcase several specific examples of the use of these toxins to develop new therapeutic strategies for numerous diseases and explain what makes these toxins promising tools in the development of drugs and drug delivery systems.
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Toxemia in Human Naturally Acquired Botulism. Toxins (Basel) 2020; 12:toxins12110716. [PMID: 33202855 PMCID: PMC7697460 DOI: 10.3390/toxins12110716] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/07/2020] [Accepted: 11/10/2020] [Indexed: 12/18/2022] Open
Abstract
Human botulism is a severe disease characterized by flaccid paralysis and inhibition of certain gland secretions, notably salivary secretions, caused by inhibition of neurotransmitter release. Naturally acquired botulism occurs in three main forms: food-borne botulism by ingestion of preformed botulinum neurotoxin (BoNT) in food, botulism by intestinal colonization (infant botulism and intestinal toxemia botulism in infants above one year and adults), and wound botulism. A rapid laboratory confirmation of botulism is required for the appropriate management of patients. Detection of BoNT in the patient's sera is the most direct way to address the diagnosis of botulism. Based on previous published reports, botulinum toxemia was identified in about 70% of food-borne and wound botulism cases, and only in about 28% of infant botulism cases, in which the diagnosis is mainly confirmed from stool sample investigation. The presence of BoNT in serum depends on the BoNT amount ingested with contaminated food or produced locally in the intestine or wound, and the timeframe between serum sampling and disease onset. BoNT levels in patient's sera are most frequently low, requiring a highly sensitive method of detection. Mouse bioassay is still the most used method of botulism identification from serum samples. However, in vitro methods based on BoNT endopeptidase activity with detection by mass spectrometry or immunoassay have been developed and depending on BoNT type, are more sensitive than the mouse bioassay. These new assays show high specificity for individual BoNT types and allow more accurate differentiation between positive toxin sera from botulism and autoimmune neuropathy patients.
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Rasetti-Escargueil C, Lemichez E, Popoff MR. Human Botulism in France, 1875-2016. Toxins (Basel) 2020; 12:toxins12050338. [PMID: 32455538 PMCID: PMC7291226 DOI: 10.3390/toxins12050338] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 11/16/2022] Open
Abstract
Botulism is a rare but severe disease which is characterized by paralysis and inhibition of secretions. Only a few cases had been reported at the end of the 19th century in France. The disease was frequent during the second world war, and then the incidence decreased progressively. However, human botulism is still present in France with 10-25 cases every year. Food-borne botulism was the main form of botulism in France, whereas infant botulism (17 cases between 2004 and 2016) was rare, and wound and inhalational botulism were exceptional. Type B was the prevalent botulism type and was mainly due to consumption of home-made or small-scale preparations of cured ham and to a lesser extent other pork meat products. In the recent period (2000-2016), a wider diversity of botulism types from various food origin including industrial foods was reported. Severe cases of type A and F botulism as well as type E botulism were more frequent. Albeit rare, the severity of botulism justifies its continued surveillance and recommendations to food industry and consumers regarding food hygiene and preservation practices.
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Matsumura T, Amatsu S, Misaki R, Yutani M, Du A, Kohda T, Fujiyama K, Ikuta K, Fujinaga Y. Fully Human Monoclonal Antibodies Effectively Neutralizing Botulinum Neurotoxin Serotype B. Toxins (Basel) 2020; 12:toxins12050302. [PMID: 32392791 PMCID: PMC7291131 DOI: 10.3390/toxins12050302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/03/2020] [Accepted: 05/04/2020] [Indexed: 01/12/2023] Open
Abstract
Botulinum neurotoxin (BoNT) is the most potent natural toxin known. Of the seven BoNT serotypes (A to G), types A, B, E, and F cause human botulism. Treatment of human botulism requires the development of effective toxin-neutralizing antibodies without side effects such as serum sickness and anaphylaxis. In this study, we generated fully human monoclonal antibodies (HuMAbs) against serotype B BoNT (BoNT/B1) using a murine–human chimera fusion partner cell line named SPYMEG. Of these HuMAbs, M2, which specifically binds to the light chain of BoNT/B1, showed neutralization activity in a mouse bioassay (approximately 10 i.p. LD50/100 µg of antibody), and M4, which binds to the C-terminal of heavy chain, showed partial protection. The combination of two HuMAbs, M2 (1.25 µg) and M4 (1.25 µg), was able to completely neutralize BoNT/B1 (80 i.p. LD50) with a potency greater than 80 i.p. LD50/2.5 µg of antibodies, and was effective both prophylactically and therapeutically in the mouse model of botulism. Moreover, this combination showed broad neutralization activity against three type B subtypes, namely BoNT/B1, BoNT/B2, and BoNT/B6. These data demonstrate that the combination of M2 and M4 is promising in terms of a foundation for new human therapeutics for BoNT/B intoxication.
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Affiliation(s)
- Takuhiro Matsumura
- Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan; (T.M.); (S.A.); (M.Y.)
| | - Sho Amatsu
- Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan; (T.M.); (S.A.); (M.Y.)
| | - Ryo Misaki
- Applied Microbiology Laboratory, International Center for Biotechnology, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan; (R.M.); (K.F.)
| | - Masahiro Yutani
- Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan; (T.M.); (S.A.); (M.Y.)
| | - Anariwa Du
- Department of Virology, Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan; (A.D.); (K.I.)
| | - Tomoko Kohda
- Department of Veterinary Sciences, School of Life and Environmental Sciences, Osaka Prefecture University, Rinkuouraikita, Izumisano, Osaka 598-8531, Japan;
| | - Kazuhito Fujiyama
- Applied Microbiology Laboratory, International Center for Biotechnology, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan; (R.M.); (K.F.)
| | - Kazuyoshi Ikuta
- Department of Virology, Center for Infectious Disease Control, Research Institute for Microbial Diseases, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan; (A.D.); (K.I.)
- The Japan Science and Technology Agency/Japan International Cooperation Agency, Science and Technology Research Partnership for Sustainable Development, Tokyo 102-0076, Japan
| | - Yukako Fujinaga
- Department of Bacteriology, Graduate School of Medical Sciences, Kanazawa University, Takara-machi, Kanazawa, Ishikawa 920-8640, Japan; (T.M.); (S.A.); (M.Y.)
- Correspondence: ; Tel.: +81-76-265-2200
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Poulain B, Lemichez E, Popoff MR. Neuronal selectivity of botulinum neurotoxins. Toxicon 2020; 178:20-32. [PMID: 32094099 DOI: 10.1016/j.toxicon.2020.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 02/03/2020] [Accepted: 02/10/2020] [Indexed: 12/12/2022]
Abstract
Botulinum neurotoxins (BoNTs) are highly potent toxins responsible for a severe disease, called botulism. They are also efficient therapeutic tools with an increasing number of indications ranging from neuromuscular dysfunction to hypersecretion syndrome, pain release, depression as well as cosmetic application. BoNTs are known to mainly target the motor-neurons terminals and to induce flaccid paralysis. BoNTs recognize a specific double receptor on neuronal cells consisting of gangliosides and synaptic vesicle protein, SV2 or synaptotagmin. Using cultured neuronal cells, BoNTs have been established blocking the release of a wide variety of neurotransmitters. However, BoNTs are more potent in motor-neurons than in the other neuronal cell types. In in vivo models, BoNT/A impairs the cholinergic neuronal transmission at the motor-neurons but also at neurons controlling secretions and smooth muscle neurons, and blocks several neuronal pathways including excitatory, inhibitory, and sensitive neurons. However, only a few reports investigated the neuronal selectivity of BoNTs in vivo. In the intestinal wall, BoNT/A and BoNT/B target mainly the cholinergic neurons and to a lower extent the other non-cholinergic neurons including serotonergic, glutamatergic, GABAergic, and VIP-neurons. The in vivo effects induced by BoNTs on the non-cholinergic neurons remain to be precisely investigated. We report here a literature review of the neuronal selectivity of BoNTs.
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Affiliation(s)
- Bernard Poulain
- Université de Strasbourg, CNRS, Institut des Neurosciences Cellulaires et Intégratives, Strasbourg, France
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29
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Harris RA, Anniballi F, Austin JW. Adult Intestinal Toxemia Botulism. Toxins (Basel) 2020; 12:E81. [PMID: 31991691 PMCID: PMC7076759 DOI: 10.3390/toxins12020081] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 12/30/2022] Open
Abstract
Intoxication with botulinum neurotoxin can occur through various routes. Foodborne botulism results after consumption of food in which botulinum neurotoxin-producing clostridia (i.e., Clostridium botulinum or strains of Clostridiumbutyricum type E or Clostridiumbaratii type F) have replicated and produced botulinum neurotoxin. Infection of a wound with C. botulinum and in situ production of botulinum neurotoxin leads to wound botulism. Colonization of the intestine by neurotoxigenic clostridia, with consequent production of botulinum toxin in the intestine, leads to intestinal toxemia botulism. When this occurs in an infant, it is referred to as infant botulism, whereas in adults or children over 1 year of age, it is intestinal colonization botulism. Predisposing factors for intestinal colonization in children or adults include previous bowel or gastric surgery, anatomical bowel abnormalities, Crohn's disease, inflammatory bowel disease, antimicrobial therapy, or foodborne botulism. Intestinal colonization botulism is confirmed by detection of botulinum toxin in serum and/or stool, or isolation of neurotoxigenic clostridia from the stool, without finding a toxic food. Shedding of neurotoxigenic clostridia in the stool may occur for a period of several weeks. Adult intestinal botulism occurs as isolated cases, and may go undiagnosed, contributing to the low reported incidence of this rare disease.
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Affiliation(s)
- Richard A. Harris
- Botulism Reference Service for Canada, Microbiology Research Division, Bureau of Microbial Hazards, Food Directorate, Health Products and Food Branch, Ottawa, ON K1A 0K9, Canada;
| | - Fabrizio Anniballi
- National Reference Centre for Botulism, Microbiological Foodborne Hazard Unit, Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, viale Regina Elena, 29900161 Rome, Italy;
| | - John W. Austin
- Botulism Reference Service for Canada, Microbiology Research Division, Bureau of Microbial Hazards, Food Directorate, Health Products and Food Branch, Ottawa, ON K1A 0K9, Canada;
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30
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Steward L, Brin MF, Brideau-Andersen A. Novel Native and Engineered Botulinum Neurotoxins. Handb Exp Pharmacol 2020; 263:63-89. [PMID: 32274579 DOI: 10.1007/164_2020_351] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Botulinum neurotoxins (BoNTs), produced by Clostridia and other bacteria, are the most potent toxins known. Their cleavage of the soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE) proteins in neurons prevents the release of neurotransmitters, thus resulting in the muscle paralysis that is characteristic of botulism. This mechanism of action has been exploited for a variety of therapeutic and cosmetic applications of BoNTs. This chapter provides an overview of the native BoNTs, including the classical serotypes and their clinical use, mosaic BoNTs, and novel BoNTs that have been recently identified in clostridial and non-clostridial strains. In addition, the modular structure of native BoNTs, which are composed of a light chain and a heavy chain, is amenable to a multitude of novel fusions and mutations using molecular biology techniques. These novel recombinant BoNTs have been used or are being developed to further characterize the biology of toxins, to assist in vaccine production, to serve as delivery vehicles to neurons, and to be utilized as novel therapeutics for both neuronal and non-neuronal cells.
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Affiliation(s)
| | - Mitchell F Brin
- Allergan plc, Irvine, CA, USA.,University of California, Irvine, CA, USA
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31
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Rasetti-Escargueil C, Lemichez E, Popoff MR. Public Health Risk Associated with Botulism as Foodborne Zoonoses. Toxins (Basel) 2019; 12:E17. [PMID: 31905908 PMCID: PMC7020394 DOI: 10.3390/toxins12010017] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/23/2019] [Accepted: 12/25/2019] [Indexed: 12/03/2022] Open
Abstract
Botulism is a rare but severe neurological disease in man and animals that is caused by botulinum neurotoxins (BoNTs) produced by Clostridium botulinum and atypical strains from other Clostridium and non-Clostridium species. BoNTs are divided into more than seven toxinotypes based on neutralization with specific corresponding antisera, and each toxinotype is subdivided into subtypes according to amino acid sequence variations. Animal species show variable sensitivity to the different BoNT toxinotypes. Thereby, naturally acquired animal botulism is mainly due to BoNT/C, D and the mosaic variants CD and DC, BoNT/CD being more prevalent in birds and BoNT/DC in cattle, whereas human botulism is more frequently in the types A, B and E, and to a lower extent, F. Botulism is not a contagious disease, since there is no direct transmission from diseased animals or man to a healthy subject. Botulism occurs via the environment, notably from food contaminated with C. botulinum spores and preserved in conditions favorable for C. botulinum growth and toxin production. The high prevalence of botulism types C, D and variants DC and CD in farmed and wild birds, and to a lower extent in cattle, raises the risk of transmission to human beings. However, human botulism is much rarer than animal botulism, and botulism types C and D are exceptional in humans. Only 15 cases or suspected cases of botulism type C and one outbreak of botulism type D have been reported in humans to date. In contrast, animal healthy carriers of C. botulinum group II, such as C. botulinum type E in fish of the northern hemisphere, and C. botulinum B4 in pigs, represent a more prevalent risk of botulism transmission to human subjects. Less common botulism types in animals but at risk of transmission to humans, can sporadically be observed, such as botulism type E in farmed chickens in France (1998-2002), botulism type B in cattle in The Netherlands (1977-1979), botulism types A and B in horses, or botulism type A in dairy cows (Egypt, 1976). In most cases, human and animal botulisms have distinct origins, and cross transmissions between animals and human beings are rather rare, accidental events. But, due to the severity of this disease, human and animal botulism requires a careful surveillance.
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Affiliation(s)
| | | | - Michel R. Popoff
- Institut Pasteur, Département de Microbiologie, Unité des Toxines Bactériennes, CNRS ERL6002, 75724 Paris, France; (C.R.-E.); (E.L.)
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32
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Martínez-Carranza M, Blasco P, Gustafsson R, Dong M, Berntsson RPA, Widmalm G, Stenmark P. Synaptotagmin Binding to Botulinum Neurotoxins. Biochemistry 2019; 59:491-498. [PMID: 31809018 DOI: 10.1021/acs.biochem.9b00554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Botulinum neurotoxins (BoNTs) are exceptionally toxic proteins that cause paralysis but are also extensively used as treatment for various medical conditions. Most BoNTs bind two receptors on neuronal cells, namely, a ganglioside and a protein receptor. Differences in the sequence between the protein receptors from different species can impact the binding affinity and toxicity of the BoNTs. Here we have investigated how BoNT/B, /DC, and /G, all three toxins that utilize synaptotagmin I and II (Syt-I and Syt-II, respectively) as their protein receptors, bind to Syt-I and -II of mouse/rat, bovine, and human origin by isothermal titration calorimetry analysis. BoNT/G had the highest affinity for human Syt-I, and BoNT/DC had the highest affinity for bovine Syt-II. As expected, BoNT/B, /DC, and /G showed very low levels of binding to human Syt-II. Furthermore, we carried out saturation transfer difference (STD) and STD-TOCSY NMR experiments that revealed the region of the Syt peptide in direct contact with BoNT/G, which demonstrate that BoNT/G recognizes the Syt peptide in a model similar to that in the established BoNT/B-Syt-II complex. Our analyses also revealed that regions outside the Syt peptide's toxin-binding region are important for the helicity of the peptide and, therefore, the binding affinity.
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Affiliation(s)
| | - Pilar Blasco
- Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Robert Gustafsson
- Department of Biochemistry and Biophysics , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Min Dong
- Department of Urology, Boston's Children Hospital, and Department of Microbiology and Immunology and Department of Surgery , Harvard Medical School , Boston , Massachusetts 02115 , United States
| | - Ronnie Per-Arne Berntsson
- Department of Medical Biochemistry and Biophysics , Umeå University , SE-90187 Umeå , Sweden.,Wallenberg Centre for Molecular Medicine , Umeå University , SE-90187 Umeå , Sweden
| | - Göran Widmalm
- Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Experimental Medical Science , Lund University , SE-221 00 Lund , Sweden
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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:toxins11120713. [PMID: 31817843 PMCID: PMC6950160 DOI: 10.3390/toxins11120713] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/12/2019] [Accepted: 11/22/2019] [Indexed: 12/14/2022] Open
Abstract
Botulinum Neurotoxins (BoNTs) are a large protein family that includes the most potent neurotoxins known to humankind. BoNTs delivered locally in humans at low doses are widely used pharmaceuticals. Reliable and quantitative detection of BoNTs is of paramount importance for the clinical diagnosis of botulism, basic research, drug development, potency determination, and detection in clinical, environmental, and food samples. Ideally, a definitive assay for BoNT should reflect the activity of each of the four steps in nerve intoxication. The in vivo mouse bioassay (MBA) is the ‘gold standard’ for the detection of BoNTs. The MBA is sensitive, robust, semi-quantitative, and reliable within its sensitivity limits. Potential drawbacks with the MBA include assay-to-assay potency variations, especially between laboratories, and false positives or negatives. These limitations can be largely avoided by careful planning and performance. Another detection method that has gained importance in recent years for research and potency determination of pharmaceutical BoNTs is cell-based assays, as these assays can be highly sensitive, quantitative, human-specific, and detect fully functional holotoxins at physiologically relevant concentrations. A myriad of other in vitro BoNT detection methods exist. This review focuses on critical factors and assay limitations of the mouse bioassay and cell-based assays for BoNT detection.
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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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35
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Kim K, Choi N, Jeon JH, Rhie GE, Choo J. SERS-Based Immunoassays for the Detection of Botulinum Toxins A and B Using Magnetic Beads. SENSORS 2019; 19:s19194081. [PMID: 31546587 PMCID: PMC6806190 DOI: 10.3390/s19194081] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 01/19/2023]
Abstract
Rapid and sensitive detection of botulinum neurotoxins (BoNTs) is important for immediate treatment with proper antitoxins. However, it is difficult to detect BoNTs at the acute phase of infection, owing to its rarity and ambiguous symptoms. To resolve this problem, we developed a surface-enhanced Raman scattering (SERS)-based immunoassay technique for the rapid and sensitive detection of BoNTs. Magnetic beads and SERS nanotags as capture substrates and detection probes, respectively, and Nile Blue A (NBA) and malachite green isothiocyanate (MGITC) as Raman reporter molecules were used for the detection of two different types of BoNTs (types A and B), respectively. The corresponding limits of detection (LODs) were determined as 5.7 ng/mL (type A) and 1.3 ng/mL (type B). Total assay time, including that for immunoreaction, washing, and detection, was less than 2 h.
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Affiliation(s)
- Kihyun Kim
- Department of Chemistry, Chung-Ang University, Seoul 06974, Korea.
| | - Namhyun Choi
- Department of Bionano Technology, Hanyang University, Ansan 426-791, Korea.
| | - Jun Ho Jeon
- Division of High-risk Pathogens, Laboratory Control of Infectious Diseases, Korea Centers for Disease Control and Prevention, Chungju 28159, Korea.
| | - Gi-Eun Rhie
- Division of High-risk Pathogens, Laboratory Control of Infectious Diseases, Korea Centers for Disease Control and Prevention, Chungju 28159, Korea.
| | - Jaebum Choo
- Department of Chemistry, Chung-Ang University, Seoul 06974, Korea.
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36
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Rasetti-Escargueil C, Popoff MR. Antibodies and Vaccines against Botulinum Toxins: Available Measures and Novel Approaches. Toxins (Basel) 2019; 11:toxins11090528. [PMID: 31547338 PMCID: PMC6783819 DOI: 10.3390/toxins11090528] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 08/29/2019] [Accepted: 09/05/2019] [Indexed: 12/18/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is produced by the anaerobic, Gram-positive bacterium Clostridium botulinum. As one of the most poisonous toxins known and a potential bioterrosism agent, BoNT is characterized by a complex mode of action comprising: internalization, translocation and proteolytic cleavage of a substrate, which inhibits synaptic exocytotic transmitter release at neuro-muscular nerve endings leading to peripheral neuroparalysis of the skeletal and autonomic nervous systems. There are seven major serologically distinct toxinotypes (A-G) of BoNT which act on different substrates. Human botulism is generally caused by BoNT/A, B and E. Due to its extreme lethality and potential use as biological weapon, botulism remains a global public health concern. Vaccination against BoNT, although an effective strategy, remains undesirable due to the growing expectation around therapeutic use of BoNTs in various pathological conditions. This review focuses on the current approaches for botulism control by immunotherapy, highlighting the future challenges while the molecular underpinnings among subtypes variants and BoNT sequences found in non-clostridial species remain to be elucidated.
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Affiliation(s)
- Christine Rasetti-Escargueil
- Institut Pasteur, Département de Microbiologie, Unité des Toxines Bactériennes, 25 Rue du Docteur Roux, 75015 Paris, France.
| | - Michel R Popoff
- Institut Pasteur, Département de Microbiologie, Unité des Toxines Bactériennes, 25 Rue du Docteur Roux, 75015 Paris, France.
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37
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Panthee S, Paudel A, Blom J, Hamamoto H, Sekimizu K. Complete Genome Sequence of Weissella hellenica 0916-4-2 and Its Comparative Genomic Analysis. Front Microbiol 2019; 10:1619. [PMID: 31396169 PMCID: PMC6667553 DOI: 10.3389/fmicb.2019.01619] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/01/2019] [Indexed: 12/21/2022] Open
Abstract
Weissella genus from Leuconostocaceae family forms a group of Gram-positive lactic acid bacteria (LAB) that mostly reside in fermented foods and some have been isolated from the environment and vertebrates including humans. Currently there are 23 recognized species, 16 complete and 37 draft genome assemblies for this genus. Weissella hellenica has been found in various sources and is characterized by their probiotic and bacteriocinogenic properties. Despite its widespread importance, little attention has been paid to genomic characterization of this species with the availability of draft assembly of two species in the public database so far. In this manuscript, we identified W. hellenica 0916-4-2 from fermented kimchi and completed its genome sequence. Comparative genomic analysis identified 88 core genes that had interspecies mean amino acid identity of more than 65%. Whole genome phylogenetic analysis showed that three W. hellenica strains clustered together and the strain 0916-4-2 was close to strain WiKim14. In silico analysis for the secondary metabolites biosynthetic gene cluster showed that Weissella are far less producers of secondary metabolites compared to other members of Leuconostocaceae. The availability of the complete genome of W. hellenica 0916-4-2 will facilitate further comparative genomic analysis of Weissella species, including studies of its biotechnological potential and improving the nutritional value of various food products.
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Affiliation(s)
- Suresh Panthee
- Institute of Medical Mycology, Teikyo University, Hachioji, Japan
| | - Atmika Paudel
- Institute of Medical Mycology, Teikyo University, Hachioji, Japan
| | - Jochen Blom
- Bioinformatics and Systems Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Hiroshi Hamamoto
- Institute of Medical Mycology, Teikyo University, Hachioji, Japan
| | - Kazuhisa Sekimizu
- Institute of Medical Mycology, Teikyo University, Hachioji, Japan.,Genome Pharmaceuticals Institute, Bunkyōku, Japan
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38
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Contreras E, Masuyer G, Qureshi N, Chawla S, Dhillon HS, Lee HL, Chen J, Stenmark P, Gill SS. A neurotoxin that specifically targets Anopheles mosquitoes. Nat Commun 2019; 10:2869. [PMID: 31253776 PMCID: PMC6599013 DOI: 10.1038/s41467-019-10732-w] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/23/2019] [Indexed: 11/24/2022] Open
Abstract
Clostridial neurotoxins, including tetanus and botulinum neurotoxins, generally target vertebrates. We show here that this family of toxins has a much broader host spectrum, by identifying PMP1, a clostridial-like neurotoxin that selectively targets anopheline mosquitoes. Isolation of PMP1 from Paraclostridium bifermentans strains collected in anopheline endemic areas on two continents indicates it is widely distributed. The toxin likely evolved from an ancestral form that targets the nervous system of similar organisms, using a common mechanism that disrupts SNARE-mediated exocytosis. It cleaves the mosquito syntaxin and employs a unique receptor recognition strategy. Our research has an important impact on the study of the evolution of clostridial neurotoxins and provides the basis for the use of P. bifermentans strains and PMP1 as innovative, environmentally friendly approaches to reduce malaria through anopheline control. So far identified clostridial neurotoxins target vertebrates. Here, Contreras et al. isolate the clostridial-like neurotoxin PMP1 from Paraclostridium bifermentans strains and show that it selectively targets anopheline mosquitoes by targeting mosquito syntaxin.
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Affiliation(s)
- Estefania Contreras
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden
| | - Nadia Qureshi
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Swati Chawla
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Harpal S Dhillon
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Han Lim Lee
- Unit of Medical Entomology, Institute for Medical Research, Jalan Pahang, 50588, Kuala Lumpur, Malaysia
| | - Jianwu Chen
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, 106 91, Stockholm, Sweden. .,Department of Experimental Medical Science, Lund University, Lund, 22100, Sweden.
| | - Sarjeet S Gill
- Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA.
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39
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Košenina S, Masuyer G, Zhang S, Dong M, Stenmark P. Crystal structure of the catalytic domain of the Weissella oryzae botulinum-like toxin. FEBS Lett 2019; 593:1403-1410. [PMID: 31111466 DOI: 10.1002/1873-3468.13446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/15/2019] [Accepted: 05/16/2019] [Indexed: 11/10/2022]
Abstract
Botulinum neurotoxins (BoNTs) are the most potent toxins known. So far, eight serotypes have been identified that all act as zinc-dependent endopeptidases targeting SNARE proteins and inhibiting the release of neurotransmitters. Recently, the first botulinum toxin-like protein was identified outside the Clostridial genus, designated BoNT/Wo in the genome of Weissella oryzae. Here, we report the 1.6 Å X-ray crystal structure of the light chain of BoNT/Wo (LC/Wo). LC/Wo presents the core fold common to BoNTs but has an unusually wide, open and negatively charged catalytic pocket, with an additional Ca2+ ion besides the zinc ion and a unique ß-hairpin motif. The structural information will help establish the substrate profile of BoNT/Wo and help our understanding of how BoNT evolved.
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Affiliation(s)
- Sara Košenina
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, Sweden
| | - Sicai Zhang
- Department of Urology, Boston Children's Hospital, Boston, MA, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA.,Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Boston, MA, USA.,Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA.,Department of Surgery, Harvard Medical School, Boston, MA, USA
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, Sweden.,Department of Experimental Medical Science, Lund University, Sweden
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40
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Rossetto O, Pirazzini M, Lista F, Montecucco C. The role of the single interchains disulfide bond in tetanus and botulinum neurotoxins and the development of antitetanus and antibotulism drugs. Cell Microbiol 2019; 21:e13037. [PMID: 31050145 PMCID: PMC6899712 DOI: 10.1111/cmi.13037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/18/2019] [Accepted: 04/30/2019] [Indexed: 01/02/2023]
Abstract
A large number of bacterial toxins consist of active and cell binding protomers linked by an interchain disulfide bridge. The largest family of such disulfide‐bridged exotoxins is that of the clostridial neurotoxins that consist of two chains and comprise the tetanus neurotoxins causing tetanus and the botulinum neurotoxins causing botulism. Reduction of the interchain disulfide abolishes toxicity, and we discuss the experiments that revealed the role of this structural element in neuronal intoxication. The redox couple thioredoxin reductase–thioredoxin (TrxR‐Trx) was identified as the responsible for reduction of this disulfide occurring on the cytosolic surface of synaptic vesicles. We then discuss the very relevant finding that drugs that inhibit TrxR‐Trx also prevent botulism. On this basis, we propose that ebselen and PX‐12, two TrxR‐Trx specific drugs previously used in clinical trials in humans, satisfy all the requirements for clinical tests aiming at evaluating their capacity to effectively counteract human and animal botulism arising from intestinal toxaemias such as infant botulism.
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Affiliation(s)
- Ornella Rossetto
- Dipartimento di Scienze Biomediche, Università di Padova, Padua, Italy
| | - Marco Pirazzini
- Dipartimento di Scienze Biomediche, Università di Padova, Padua, Italy
| | - Florigio Lista
- Sezione di Istologia e Biologia Molecolare, Centro di ricerca Medica e Veterinaria del Ministero della Difesa, Rome, Italy
| | - Cesare Montecucco
- Dipartimento di Scienze Biomediche, Università di Padova, Padua, Italy.,Istituto Neuroscienze del CNR, Università di Padova, Padua, Italy
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41
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Bioinformatic discovery of a toxin family in Chryseobacterium piperi with sequence similarity to botulinum neurotoxins. Sci Rep 2019; 9:1634. [PMID: 30733520 PMCID: PMC6367388 DOI: 10.1038/s41598-018-37647-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 12/05/2018] [Indexed: 11/12/2022] Open
Abstract
Clostridial neurotoxins (CNTs), which include botulinum neurotoxins (BoNTs) and tetanus neurotoxin (TeNT), are the most potent toxins known to science and are the causative agents of botulism and tetanus, respectively. The evolutionary origins of CNTs and their relationships to other proteins remains an intriguing question. Here we present a large-scale bioinformatic screen for putative toxin genes in all currently available genomes. We detect a total of 311 protein sequences displaying at least partial homology to BoNTs, including 161 predicted toxin sequences that have never been characterized. We focus on a novel toxin family from Chryseobacterium piperi with homology to BoNTs. We resequenced the genome of C. piperi to confirm and further analyze the genomic context of these toxins, and also examined their potential toxicity by expression of the protease domain of one C. piperi toxin in human cells. Our analysis suggests that these C. piperi sequences encode a novel family of metalloprotease toxins that are distantly related to BoNTs with similar domain architecture. These toxins target a yet unknown class of substrates, potentially reflecting divergence in substrate specificity between the metalloprotease domains of these toxins and the related metalloprotease domain of clostridial neurotoxins.
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42
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Neurobiology and therapeutic applications of neurotoxins targeting transmitter release. Pharmacol Ther 2019; 193:135-155. [DOI: 10.1016/j.pharmthera.2018.08.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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43
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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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44
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Scalfaro C, Auricchio B, De Medici D, Anniballi F. Foodborne botulism: an evolving public health challenge. Infect Dis (Lond) 2018; 51:97-101. [DOI: 10.1080/23744235.2018.1524584] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Concetta Scalfaro
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Bruna Auricchio
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Dario De Medici
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
| | - Fabrizio Anniballi
- Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità, Rome, Italy
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45
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Abstract
Botulinum neurotoxins (BoNTs) and tetanus neurotoxin (TeNT) are the most potent toxins known and cause botulism and tetanus, respectively. BoNTs are also widely utilized as therapeutic toxins. They contain three functional domains responsible for receptor-binding, membrane translocation, and proteolytic cleavage of host proteins required for synaptic vesicle exocytosis. These toxins also have distinct features: BoNTs exist within a progenitor toxin complex (PTC), which protects the toxin and facilitates its absorption in the gastrointestinal tract, whereas TeNT is uniquely transported retrogradely within motor neurons. Our increasing knowledge of these toxins has allowed the development of engineered toxins for medical uses. The discovery of new BoNTs and BoNT-like proteins provides additional tools to understand the evolution of the toxins and to engineer toxin-based therapeutics. This review summarizes the progress on our understanding of BoNTs and TeNT, focusing on the PTC, receptor recognition, new BoNT-like toxins, and therapeutic toxin engineering.
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Affiliation(s)
- Min Dong
- Department of Urology, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Geoffrey Masuyer
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden;
| | - Pål Stenmark
- Department of Biochemistry and Biophysics, Stockholm University, 106 91 Stockholm, Sweden; .,Department of Experimental Medical Science, Lund University, 221 00 Lund, Sweden
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46
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Davies JR, Liu SM, Acharya KR. Variations in the Botulinum Neurotoxin Binding Domain and the Potential for Novel Therapeutics. Toxins (Basel) 2018; 10:toxins10100421. [PMID: 30347838 PMCID: PMC6215321 DOI: 10.3390/toxins10100421] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/11/2018] [Accepted: 10/18/2018] [Indexed: 01/23/2023] Open
Abstract
Botulinum neurotoxins (BoNTs) are categorised into immunologically distinct serotypes BoNT/A to /G). Each serotype can also be further divided into subtypes based on differences in amino acid sequence. BoNTs are ~150 kDa proteins comprised of three major functional domains: an N-terminal zinc metalloprotease light chain (LC), a translocation domain (HN), and a binding domain (HC). The HC is responsible for targeting the BoNT to the neuronal cell membrane, and each serotype has evolved to bind via different mechanisms to different target receptors. Most structural characterisations to date have focussed on the first identified subtype within each serotype (e.g., BoNT/A1). Subtype differences within BoNT serotypes can affect intoxication, displaying different botulism symptoms in vivo, and less emphasis has been placed on investigating these variants. This review outlines the receptors for each BoNT serotype and describes the basis for the highly specific targeting of neuronal cell membranes. Understanding receptor binding is of vital importance, not only for the generation of novel therapeutics but also for understanding how best to protect from intoxication.
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Affiliation(s)
- Jonathan R Davies
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
| | - Sai Man Liu
- Ipsen Bioinnovation Limited, Abingdon OX14 4RY, UK.
| | - K Ravi Acharya
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK.
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47
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Benoit RM. Botulinum Neurotoxin Diversity from a Gene-Centered View. Toxins (Basel) 2018; 10:E310. [PMID: 30071587 PMCID: PMC6115791 DOI: 10.3390/toxins10080310] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 07/24/2018] [Accepted: 07/30/2018] [Indexed: 12/16/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) rank amongst the most potent toxins known. The factors responsible for the emergence of the many known and yet unknown BoNT variants remain elusive. It also remains unclear why anaerobic bacteria that are widely distributed in our environment and normally do not pose a threat to humans, produce such deadly toxins. Even the possibility of accidental toxicity to humans has not been excluded. Here, I review the notion that BoNTs may have specifically evolved to target vertebrates. Considering the extremely complex molecular architecture of the toxins, which enables them to reach the bloodstream, to recognize and enter neurons, and to block neurotransmitter release, it seems highly unlikely that BoNT toxicity to vertebrates is a coincidence. The carcass⁻maggot cycle provides a plausible explanation for a natural role of the toxins: to enable mass reproduction of bacteria, spores, and toxins, using toxin-unaffected invertebrates, such as fly maggots, as the vectors. There is no clear correlation between toxigenicity and a selective advantage of clostridia in their natural habitat. Possibly, non-toxigenic strains profit from carcasses resulting from the action of toxigenic strains. Alternatively, a gene-centered view of toxin evolution would also explain this observation. Toxin-coding mobile genetic elements may have evolved as selfish genes, promoting their own propagation, similar to commensal viruses, using clostridia and other bacteria as the host. Research addressing the role of BoNTs in nature and the origin of toxin variability goes hand in hand with the identification of new toxin variants and the design of improved toxin variants for medical applications. These research directions may also reveal yet unknown natural antidotes against these extremely potent neurotoxins.
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Affiliation(s)
- Roger M Benoit
- Laboratory of Biomolecular Research, Division of Biology and Chemistry, Paul Scherrer Institute, Villigen CH-5232, Switzerland.
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48
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Tehran DA, Pirazzini M. Preparation of Cerebellum Granule Neurons from Mouse or Rat Pups and Evaluation of Clostridial Neurotoxin Activity and Their Inhibitors by Western Blot and Immunohistochemistry. Bio Protoc 2018; 8:e2918. [PMID: 34395747 DOI: 10.21769/bioprotoc.2918] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/12/2018] [Accepted: 06/17/2018] [Indexed: 01/29/2023] Open
Abstract
Cerebellar Granule Neurons (CGN) from post-natal rodents have been widely used as a model to study neuronal development, physiology and pathology. CGN cultured in vitro maintain the same features displayed in vivo by mature cerebellar granule cells, including the development of a dense neuritic network, neuronal activity, neurotransmitter release and the expression of neuronal protein markers. Moreover, CGN represent a convenient model for the study of Clostridial Neurotoxins (CNT), most notably known as Tetanus and Botulinum neurotoxins, as they abundantly express both CNT receptors and intraneuronal substrates, i.e., Soluble N-ethylmaleimide-sensitive factor activating protein receptors (SNARE proteins). Here, we describe a protocol for obtaining a highly pure culture of CGN from postnatal rats/mice and an easy procedure for their intoxication with CNT. We also illustrate handy methods to evaluate CNT activity and their inhibition.
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Affiliation(s)
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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49
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Fonfria E, Elliott M, Beard M, Chaddock JA, Krupp J. Engineering Botulinum Toxins to Improve and Expand Targeting and SNARE Cleavage Activity. Toxins (Basel) 2018; 10:toxins10070278. [PMID: 29973505 PMCID: PMC6071219 DOI: 10.3390/toxins10070278] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 06/29/2018] [Accepted: 07/01/2018] [Indexed: 12/14/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are highly successful protein therapeutics. Over 40 naturally occurring BoNTs have been described thus far and, of those, only 2 are commercially available for clinical use. Different members of the BoNT family present different biological properties but share a similar multi-domain structure at the molecular level. In nature, BoNTs are encoded by DNA in producing clostridial bacteria and, as such, are amenable to recombinant production through insertion of the coding DNA into other bacterial species. This, in turn, creates possibilities for protein engineering. Here, we review the production of BoNTs by the natural host and also recombinant production approaches utilised in the field. Applications of recombinant BoNT-production include the generation of BoNT-derived domain fragments, the creation of novel BoNTs with improved performance and enhanced therapeutic potential, as well as the advancement of BoNT vaccines. In this article, we discuss site directed mutagenesis, used to affect the biological properties of BoNTs, including approaches to alter their binding to neurons and to alter the specificity and kinetics of substrate cleavage. We also discuss the target secretion inhibitor (TSI) platform, in which the neuronal binding domain of BoNTs is substituted with an alternative cellular ligand to re-target the toxins to non-neuronal systems. Understanding and harnessing the potential of the biological diversity of natural BoNTs, together with the ability to engineer novel mutations and further changes to the protein structure, will provide the basis for increasing the scope of future BoNT-based therapeutics.
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Affiliation(s)
- Elena Fonfria
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Mark Elliott
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Matthew Beard
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - John A Chaddock
- Ipsen Bioinnovation, 102 Park Drive, Milton Park, Abingdon OX14 4RY, UK.
| | - Johannes Krupp
- Ipsen Innovation, 5 Avenue du Canada, 91940 Les Ulis, France.
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50
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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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