1
|
Wei Y, Li G, Wang Z, Qian K, Zhang S, Zhang L, Lei C, Hu S. Development and characterization of a novel neutralizing scFv vectored immunoprophylaxis against botulinum toxin type A. J Drug Target 2024; 32:213-222. [PMID: 38164940 DOI: 10.1080/1061186x.2023.2301418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 10/18/2023] [Indexed: 01/03/2024]
Abstract
Botulinum toxin is a protein toxin secreted by Clostridium botulinum that is strongly neurotoxic. Due to its characteristics of being super toxic, quick acting, and difficult to prevent, the currently reported antiviral studies focusing on monoclonal antibodies have limited effectiveness. Therefore, for the sake of effectively prevention and treatment of botulism and to maintain country biosecurity as well as the health of the population, in this study, we intend to establish a single chain antibody (scFv) targeting the carboxyl terminal binding functional domain of the botulinum neurotoxin heavy chain (BONT/AHc) of botulinum neurotoxin type A, and explore the value of a new passive immune method in antiviral research which based on adeno-associated virus (AAV) mediated vector immunoprophylaxis (VIP) strategy. The scFv small-molecular single-chain antibody sequenced, designed, constructed, expressed and purified by hybridoma has high neutralising activity and affinity level, which can lay a good foundation for the modification and development of antibody engineering drugs. In vivo experiments, AAV-mediated scFv engineering drug has good anti-BONT/A toxin neutralisation ability, has advantages of simple operation, stable expression and good efficacy, and may be one of the effective treatment strategies for long-term prevention and protection of BONT/A botulinum neurotoxin.
Collapse
Affiliation(s)
- Yongpeng Wei
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
- Hepatic Surgery Department V, The Third Affiliated Hospital, Second Military Medical University, Shanghai, China
| | - Guangyao Li
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
- Department of Biomedical Engineering, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Zhuo Wang
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
- Hepatic Surgery Department V, The Third Affiliated Hospital, Second Military Medical University, Shanghai, China
| | - Kewen Qian
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
- Department of Biomedical Engineering, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China
| | - Shuyi Zhang
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
| | - Lingling Zhang
- Department of Central Laboratory, Clinical Research Center of Changhai Hospital, Shanghai, China
| | - Changhai Lei
- Department of Biophysics, College of Basic Medical Sciences, Second Military Medical University, Shanghai, China
| | - Shi Hu
- Department of Biomedical Engineering, College of Basic Medical Sciences, Naval Medical University (Second Military Medical University), Shanghai, China
| |
Collapse
|
2
|
Jiang Y, Wang R, Guo J, Cheng K, Chen L, Wang X, Li Y, Du P, Gao C, Lu J, Yu Y, Yang Z. Isolation and characterization of Hc-targeting chimeric heavy chain antibodies neutralizing botulinum neurotoxin type B. Front Immunol 2024; 15:1380694. [PMID: 38779676 PMCID: PMC11109933 DOI: 10.3389/fimmu.2024.1380694] [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: 02/02/2024] [Accepted: 04/11/2024] [Indexed: 05/25/2024] Open
Abstract
Background Botulinum neurotoxin (BoNT) produced by Clostridium botulinum is one of the most potent known toxins. Moreover, BoNT is classified as one of the most important biological warfare agents that threatens the biosafety of the world. Currently, the approved treatment for botulism in humans is the use of polyvalent horse serum antitoxins. However, they are greatly limited because of insufficient supply and adverse reactions. Thus, treatment of human botulism requires the development of effective toxin-neutralizing antibodies. Considering their advantages, neutralizing nanobodies will play an increasing role as BoNTs therapeutics. Methods Herein, neutralizing nanobodies binding to the heavy chain (Hc) domain of BoNT/B (BHc) were screened from a phage display library. Then, BoNT/B-specific clones were identified and fused with the human Fc fragment (hFc) to form chimeric heavy chain antibodies. Finally, the affinity, specificity, and neutralizing activity of antibodies against BoNT/B in vivo were evaluated. Results The B5-hFc, B9-hFc and B12-hFc antibodies demonstrated high affinity for BHc in the nanomolar range. The three antibodies were proven to have potent neutralizing activity against BoNT/B in vivo. Conclusion The results demonstrate that inhibiting toxin binding to the host receptor is an efficient strategy and the three antibodies could be used as candidates for the further development of drugs to prevent and treat botulism.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Jiansheng Lu
- Beijing Institute of Biotechnology, Beijing, China
| | - Yunzhou Yu
- Beijing Institute of Biotechnology, Beijing, China
| | - Zhixin Yang
- Beijing Institute of Biotechnology, Beijing, China
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Li Y, Chen Y, Cui J, Liu D, Zhang W, Xue C, Xiong X, Liu G, Chen H. Preparation and characterization of a neutralizing murine monoclonal antibody against tetanus toxin. J Immunol Methods 2023; 513:113427. [PMID: 36652969 DOI: 10.1016/j.jim.2023.113427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 11/11/2022] [Accepted: 01/11/2023] [Indexed: 01/16/2023]
Abstract
After Clostridium tetani infects the human body, it propagates under anaerobic conditions and produces tetanus neurotoxin (TeNT). TeNT can affect the central nervous system, inhibit the release of neurotransmitters, and result in respiratory failure, which are the root causes of death in tetanus patients. Identifying monoclonal antibodies (mAbs) targeting TeNT with neutralizing activity is urgently needed for the prevention and treatment of tetanus infection. In this study, through immunizing BALB/c mice with tetanus toxoid (TT), we obtained six positive hybridoma cell lines (1A7, 2C7, 3A7, 3H4, 4C1, and 4E12). Antibody isotyping showed that the antibodies are all of the IgG1/κ subclass. Ascites fluid was prepared by allogeneic ascites induction and the antibodies were purified through protein G affinity chromatography columns. Purities of the produced murine mAbs were all greater than 95%. All six antibodies bound to linear epitopes, among which 3A7 bound to the TeNT/L domain and the other five antibodies bound to the TeNT/Hc domain. Moreover, the affinity constants of these six antibodies against the antigen were all in the nanomolar range, and the affinity of 4E12 antibody reached the picomolar range. Results from toxin-neutralization assays in mice showed that 2C7 antibody delayed animal death, while 1A7, 3A7, 3H4, and 4E12 antibodies conferred partial protection. Additionally, 4C1 antibody offered complete protection, as 200 μg of 4C1 antibody fully protected against toxin challenge with 10 LD50 of TeNT and had a window period of 1 h. Antibody epitope grouping results revealed that the binding epitopes of 4C1 antibody were different from those of the other five antibodies. When 4C1 antibody was used in combination with another antibody, the neutralizing activities of antibodies were all evidently enhanced. Specifically, 4C1 combined with 3A7 antibody led to the greatest improvement in neutralizing activities, and 20 μg antibodies total (10 + 10 μg) fully protected against toxin challenge with 10 LD50. When 4E12, 3A7, and 4C1 antibodies were used in combination, 18 μg antibodies total (6 + 6 + 6 μg) completely neutralized 10 LD50 toxin. The present study derived murine mAbs with neutralizing activities and laid the foundation for follow-up therapeutic drug development for TeNT poisoning as well as establishment of TeNT detection methods.
Collapse
Affiliation(s)
- Yi Li
- Academy of Military Medical Sciences, Beijing 100080, China
| | - Yangyang Chen
- College of Pharmacy, Harbin University of Commerce, Harbin 1500076, China
| | - Jiazhen Cui
- Academy of Military Medical Sciences, Beijing 100080, China
| | - Dongqi Liu
- College of Pharmacy, Harbin University of Commerce, Harbin 1500076, China
| | - Weicai Zhang
- Academy of Military Medical Sciences, Beijing 100080, China
| | - Chong Xue
- Academy of Military Medical Sciences, Beijing 100080, China
| | - Xianghua Xiong
- Academy of Military Medical Sciences, Beijing 100080, China.
| | - Gang Liu
- Academy of Military Medical Sciences, Beijing 100080, China.
| | - Huipeng Chen
- Academy of Military Medical Sciences, Beijing 100080, China.
| |
Collapse
|
5
|
Li CY, Lv SW, Yang L, Wang J, Liu JM, Wang S. Facile preparation of uniform-sized covalent organic framework nanoflowers as versatile sample-pretreatment platforms for sensitive and specific determination of hazardous substances. JOURNAL OF HAZARDOUS MATERIALS 2022; 438:129566. [PMID: 35999751 DOI: 10.1016/j.jhazmat.2022.129566] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/28/2022] [Accepted: 07/07/2022] [Indexed: 06/15/2023]
Abstract
Covalent-organic frameworks (COFs) have lately received extensive interest for their outstanding performance, especially to adsorption of hazards, while easy-preparation of uniform-sized COFs hold a great challenge. This research presented a simple synthesis method of flower-shaped COF (nanoflower) with strong hydrophobic surface at room temperature. Taking advantage of its easy-prepared and uniform-sized features, we proposed a versatile and efficient sample-pretreatment platform by employing the nanoflower COF for affinity adsorption of various hydrophobic biotoxins and further surface imprinting for selective enrichment of specific biotoxin (COF@MIP), respectively. The COF@MIP was integrating COF with molecular imprinting technique to achieve selective identification of sterigmatocystin (ST) with high specificity and sensitivity. They both exhibited well reusability, preserving 81% of initial activity after being used for six cycles. The as-prepared materials coupled with offline solid phase extraction (SPE) and high performance liquid chromatography (HPLC) were successfully applied to five common cereals with good recoveries in the range of 70.3-100.7%. Moreover, the principle of versatile sample pretreatment and detection platform based on the facile-prepared and uniform-sized COF nanoflower would be easily extended to other hazards. It provided a prospective approach for the pretreatment and determination of hazardous substances with low level in complex sample matrix.
Collapse
Affiliation(s)
- Chun-Yang Li
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China
| | - Shi-Wen Lv
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China
| | - Lu Yang
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China
| | - Jin Wang
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China
| | - Jing-Min Liu
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China.
| | - Shuo Wang
- Tianjin Key Laboratory of Food Science and Health, School of Medicine, Nankai University, Tianjin 300071, China; State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China.
| |
Collapse
|
6
|
Fan Y, Sun Z, Conrad F, Wen W, Zhao L, Lou J, Zhou Y, Farr-Jones S, Marks JD. Multicolor fluorescence activated cell sorting to generate humanized monoclonal antibody binding seven subtypes of BoNT/F. PLoS One 2022; 17:e0273512. [PMID: 36048906 PMCID: PMC9436041 DOI: 10.1371/journal.pone.0273512] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 08/09/2022] [Indexed: 11/23/2022] Open
Abstract
Generating specific monoclonal antibodies (mAbs) that neutralize multiple antigen variants is challenging. Here, we present a strategy to generate mAbs that bind seven subtypes of botulinum neurotoxin serotype F (BoNT/F) that differ from each other in amino acid sequence by up to 36%. Previously, we identified 28H4, a mouse mAb with poor cross-reactivity to BoNT/F1, F3, F4, and F6 and with no detectable binding to BoNT/F2, F5, or F7. Using multicolor labeling of the different BoNT/F subtypes and fluorescence-activated cell sorting (FACS) of yeast displayed single-chain Fv (scFv) mutant libraries, 28H4 was evolved to a humanized mAb hu6F15.4 that bound each of seven BoNT/F subtypes with high affinity (KD 5.81 pM to 659.78 pM). In contrast, using single antigen FACS sorting, affinity was increased to the subtype used for sorting but with a decrease in affinity for other subtypes. None of the mAb variants showed any binding to other BoNT serotypes or to HEK293 or CHO cell lysates by flow cytometry, thus demonstrating stringent BoNT/F specificity. Multicolor FACS-mediated antibody library screening is thus proposed as a general method to generate multi-specific antibodies to protein subtypes such as toxins or species variants.
Collapse
Affiliation(s)
- Yongfeng Fan
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Zhengda Sun
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Fraser Conrad
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Weihua Wen
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Lequn Zhao
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Jianlong Lou
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Yu Zhou
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Shauna Farr-Jones
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - James D. Marks
- Zuckerberg San Francisco General Hospital and Trauma Center, Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| |
Collapse
|
7
|
First-in-Human Clinical Trial to Assess the Safety, Tolerability and Pharmacokinetics of Single Doses of NTM-1633, a Novel Mixture of Monoclonal Antibodies against Botulinum Toxin E. Antimicrob Agents Chemother 2022; 66:e0173221. [PMID: 35311524 DOI: 10.1128/aac.01732-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Botulism is a rare, life-threatening paralytic disease caused by botulinum neurotoxin (BoNT). Available treatments including an equine antitoxin and human immune globulin are given postexposure and challenging to produce and administer. NTM-1633 is an equimolar mixture of 3 human IgG monoclonal antibodies, E1, E2, and E3, targeting BoNT serotype E (BoNT/E). This first-in-human study assessed the safety, tolerability, pharmacokinetics (PK), and immunogenicity of NTM-1633. This double-blind, single-center, placebo-controlled dose escalation study randomized 3 cohorts of healthy volunteers to receive a single intravenous dose of NTM-1633 (0.033, 0.165, or 0.330 mg/kg) or saline placebo. Safety monitoring included physical examinations, clinical laboratory studies, and vital signs. Blood sampling was performed at prespecified time points for PK and immunogenicity analyses. Twenty-four subjects received study product (18 NTM-1633; 6 placebo), and no deaths were reported. An unrelated serious adverse event was reported in a placebo subject. Adverse events in the NTM-1633 groups were generally mild and similar in frequency and severity to the placebo group, and no safety signal was identified. NTM-1633 has a favorable PK profile with a half-life >10 days for the 0.330 mg/kg dose and an approximately linear relationship with respect to maximum concentration and area under the concentration-time curve (AUC0→t). NTM-1633 also demonstrated low immunogenicity. NTM-1633 is well tolerated at the administered doses. The favorable safety, PK, and immunogenicity profile supports further development as a treatment for BoNT/E intoxication and postexposure prophylaxis.
Collapse
|
8
|
Abstract
![]()
The paradigm of antivirulence
therapy dictates that bacterial pathogens
are specifically disarmed but not killed by neutralizing their virulence
factors. Clearance of the invading pathogen by the immune system is
promoted. As compared to antibiotics, the pathogen-selective antivirulence
drugs hold promise to minimize collateral damage to the beneficial
microbiome. Also, selective pressure for resistance is expected to
be lower because bacterial viability is not directly affected. Antivirulence
drugs are being developed for stand-alone prophylactic and therapeutic
treatments but also for combinatorial use with antibiotics. This Review
focuses on drug modalities that target bacterial exotoxins after the
secretion or release-upon-lysis. Exotoxins have a significant and
sometimes the primary role as the disease-causing virulence factor,
and thereby they are attractive targets for drug development. We describe
the key pre-clinical and clinical trial data that have led to the
approval of currently used exotoxin-targeted drugs, namely the monoclonal
antibodies bezlotoxumab (toxin B/TcdB, Clostridioides difficile), raxibacumab (anthrax toxin, Bacillus anthracis), and obiltoxaximab (anthrax toxin, Bacillus anthracis), but also to challenges with some of the promising leads. We also
highlight the recent developments in pre-clinical research sector
to develop exotoxin-targeted drug modalities, i.e., monoclonal antibodies,
antibody fragments, antibody mimetics, receptor analogs, neutralizing
scaffolds, dominant-negative mutants, and small molecules. We describe
how these exotoxin-targeted drug modalities work with high-resolution
structural knowledge and highlight their advantages and disadvantages
as antibiotic alternatives.
Collapse
Affiliation(s)
- Moona Sakari
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arttu Laisi
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| | - Arto T. Pulliainen
- Institute of Biomedicine, Research Unit for Infection and Immunity, University of Turku, Kiinamyllynkatu 10, FI-20520 Turku, Finland
| |
Collapse
|
9
|
Lam KH, Tremblay JM, Perry K, Ichtchenko K, Shoemaker CB, Jin R. Probing the structure and function of the protease domain of botulinum neurotoxins using single-domain antibodies. PLoS Pathog 2022; 18:e1010169. [PMID: 34990480 PMCID: PMC8769338 DOI: 10.1371/journal.ppat.1010169] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/19/2022] [Accepted: 12/04/2021] [Indexed: 12/03/2022] Open
Abstract
Botulinum neurotoxins (BoNTs) are among the deadliest of bacterial toxins. BoNT serotype A and B in particular pose the most serious threat to humans because of their high potency and persistence. To date, there is no effective treatment for late post-exposure therapy of botulism patients. Here, we aim to develop single-domain variable heavy-chain (VHH) antibodies targeting the protease domains (also known as the light chain, LC) of BoNT/A and BoNT/B as antidotes for post-intoxication treatments. Using a combination of X-ray crystallography and biochemical assays, we investigated the structures and inhibition mechanisms of a dozen unique VHHs that recognize four and three non-overlapping epitopes on the LC of BoNT/A and BoNT/B, respectively. We show that the VHHs that inhibit the LC activity occupy the extended substrate-recognition exosites or the cleavage pocket of LC/A or LC/B and thus block substrate binding. Notably, we identified several VHHs that recognize highly conserved epitopes across BoNT/A or BoNT/B subtypes, suggesting that these VHHs exhibit broad subtype efficacy. Further, we identify two novel conformations of the full-length LC/A, that could aid future development of inhibitors against BoNT/A. Our studies lay the foundation for structure-based engineering of protein- or peptide-based BoNT inhibitors with enhanced potencies and cross-subtypes properties.
Collapse
Affiliation(s)
- Kwok-ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| | - Jacqueline M. Tremblay
- Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Kay Perry
- NE-CAT, Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, United States of America
| | - Charles B. Shoemaker
- Tufts Cummings School of Veterinary Medicine, North Grafton, Massachusetts, United States of America
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, United States of America
| |
Collapse
|
10
|
Neutralizing Concentrations of Anti-Botulinum Toxin Antibodies Positively Correlate with Mouse Neutralization Assay Results in a Guinea Pig Model. Toxins (Basel) 2021; 13:toxins13090671. [PMID: 34564675 PMCID: PMC8471557 DOI: 10.3390/toxins13090671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/24/2021] [Accepted: 09/16/2021] [Indexed: 11/17/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are some of the most toxic proteins known and can induce respiratory failure requiring long-term intensive care. Treatment of botulism includes the administration of antitoxins. Monoclonal antibodies (mAbs) hold considerable promise as BoNT therapeutics and prophylactics, due to their potency and safety. A three-mAb combination has been developed that specifically neutralizes BoNT serotype A (BoNT/A), and a separate three mAb combination has been developed that specifically neutralizes BoNT serotype B (BoNT/B). A six mAb cocktail, designated G03-52-01, has been developed that combines the anti-BoNT/A and anti-BoNT/B mAbs. The pharmacokinetics and neutralizing antibody concentration (NAC) of G03-52-01 has been determined in guinea pigs, and these parameters were correlated with protection against an inhalation challenge of BoNT/A1 or BoNT/B1. Previously, it was shown that each antibody demonstrated a dose-dependent mAb serum concentration and reached maximum circulating concentrations within 48 h after intramuscular (IM) or intraperitoneal (IP) injection and that a single IM injection of G03-52-01 administered 48 h pre-exposure protected guinea pigs against an inhalation challenge of up to 93 LD50s of BoNT/A1 and 116 LD50s of BoNT/B1. The data presented here advance our understanding of the relationship of the neutralizing NAC to the measured circulating antibody concentration and provide additional support that a single IM or intravenous (IV) administration of G03-52-01 will provide pre-exposure prophylaxis against botulism from an aerosol exposure of BoNT/A and BoNT/B.
Collapse
|
11
|
Larbouret C, Gros L, Pèlegrin A, Chardès T. Improving Biologics' Effectiveness in Clinical Oncology: From the Combination of Two Monoclonal Antibodies to Oligoclonal Antibody Mixtures. Cancers (Basel) 2021; 13:cancers13184620. [PMID: 34572847 PMCID: PMC8465647 DOI: 10.3390/cancers13184620] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/01/2021] [Accepted: 09/09/2021] [Indexed: 01/03/2023] Open
Abstract
Simple Summary The approval of the two antibody combinations trastuzumab/pertuzumab and ipilimumab/nivolumab in oncology has paved the way for novel antibody combinations or oligoclonal antibody mixtures to improve their efficacy in cancer. The underlying biological mechanisms and challenges of these strategies will be discussed using data from clinical trials listed in databases. These therapeutic combinations also lead to questions on how to optimize their formulation and delivery to induce a therapeutic polyclonal response in patients with cancer. Abstract Monoclonal antibodies have revolutionized the treatment of many diseases, but their clinical efficacy remains limited in some other cases. Pre-clinical and clinical trials have shown that combinations of antibodies that bind to the same target (homo-combinations) or to different targets (hetero-combinations) to mimic the polyclonal humoral immune response improve their therapeutic effects in cancer. The approval of the trastuzumab/pertuzumab combination for breast cancer and then of the ipilimumab/nivolumab combination for melanoma opened the way to novel antibody combinations or oligoclonal antibody mixtures as more effective biologics for cancer management. We found more than 300 phase II/III clinical trials on antibody combinations, with/without chemotherapy, radiotherapy, small molecules or vaccines, in the ClinicalTrials.gov database. Such combinations enhance the biological responses and bypass the resistance mechanisms observed with antibody monotherapy. Usually, such antibody combinations are administered sequentially as separate formulations. Combined formulations have also been developed in which separately produced antibodies are mixed before administration or are produced simultaneously in a single cell line or a single batch of different cell lines as a polyclonal master cell bank. The regulation, toxicity and injection sequence of these oligoclonal antibody mixtures still need to be addressed in order to optimize their delivery and their therapeutic effects.
Collapse
Affiliation(s)
- Christel Larbouret
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Institut Régional du Cancer de Montpellier (ICM), Inserm U1194, Université de Montpellier, 34298 Montpellier, France; (L.G.); (A.P.); (T.C.)
- Correspondence: ; Tel.: +33-411-283-110
| | - Laurent Gros
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Institut Régional du Cancer de Montpellier (ICM), Inserm U1194, Université de Montpellier, 34298 Montpellier, France; (L.G.); (A.P.); (T.C.)
- Centre National de la Recherche Scientifique (CNRS), 75016 Paris, France
| | - André Pèlegrin
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Institut Régional du Cancer de Montpellier (ICM), Inserm U1194, Université de Montpellier, 34298 Montpellier, France; (L.G.); (A.P.); (T.C.)
| | - Thierry Chardès
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Institut Régional du Cancer de Montpellier (ICM), Inserm U1194, Université de Montpellier, 34298 Montpellier, France; (L.G.); (A.P.); (T.C.)
- Centre National de la Recherche Scientifique (CNRS), 75016 Paris, France
| |
Collapse
|
12
|
A Four-Monoclonal Antibody Combination Potently Neutralizes Multiple Botulinum Neurotoxin Serotypes C and D. Toxins (Basel) 2021; 13:toxins13090641. [PMID: 34564645 PMCID: PMC8472335 DOI: 10.3390/toxins13090641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 12/04/2022] Open
Abstract
Human botulism can be caused by botulinum neurotoxin (BoNT) serotypes A to G. Here, we present an antibody-based antitoxin composed of four human monoclonal antibodies (mAbs) against BoNT/C, BoNT/D, and their mosaic toxins. This work built on our success in generating protective mAbs to BoNT /A, B and E serotypes. We generated mAbs from human immune single-chain Fv (scFv) yeast-display libraries and isolated scFvs with high affinity for BoNT/C, BoNT/CD, BoNT/DC and BoNT/D serotypes. We identified four mAbs that bound non-overlapping epitopes on multiple serotypes and mosaic BoNTs. Three of the mAbs underwent molecular evolution to increase affinity. A four-mAb combination provided high-affinity binding and BoNT neutralization of both serotypes and their mosaic toxins. The mAbs have potential utility as therapeutics and as diagnostics capable of recognizing and neutralizing BoNT/C and BoNT/D serotypes and their mosaic toxins. A derivative of the four-antibody combination (NTM-1634) completed a Phase 1 clinical trial (Snow et al., Antimicrobial Agents and Chemotherapy, 2019) with no drug-related serious adverse events.
Collapse
|
13
|
Brier S, Rasetti-Escargueil C, Wijkhuisen A, Simon S, Marechal M, Lemichez E, Popoff MR. Characterization of a highly neutralizing single monoclonal antibody to botulinum neurotoxin type A. FASEB J 2021; 35:e21540. [PMID: 33817838 DOI: 10.1096/fj.202002492r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/15/2023]
Abstract
Compared to conventional antisera strategies, monoclonal antibodies (mAbs) represent an alternative and safer way to treat botulism, a fatal flaccid paralysis due to botulinum neurotoxins (BoNTs). In addition, mAbs offer the advantage to be produced in a reproducible manner. We previously identified a unique and potent mouse mAb (TA12) targeting BoNT/A1 with high affinity and neutralizing activity. In this study, we characterized the molecular basis of TA12 neutralization by combining Hydrogen/Deuterium eXchange Mass Spectrometry (HDX-MS) with site-directed mutagenesis and functional studies. We found that TA12 recognizes a conformational epitope located at the interface between the HCN and HCC subdomains of the BoNT/A1 receptor-binding domain (HC ). The TA12-binding interface shares common structural features with the ciA-C2 VHH epitope and lies on the face opposite recognized by ciA-C2- and the CR1/CR2-neutralizing mAbs. The single substitution of N1006 was sufficient to affect TA12 binding to HC confirming the position of the epitope. We further uncovered that the TA12 epitope overlaps with the BoNT/A1-binding site for both the neuronal cell surface receptor synaptic vesicle glycoprotein 2 isoform C (SV2C) and the GT1b ganglioside. Hence, TA12 potently blocks the entry of BoNT/A1 into neurons by interfering simultaneously with the binding of SV2C and to a lower extent GT1b. Our study reveals the unique neutralization mechanism of TA12 and emphasizes on the potential of using single mAbs for the treatment of botulism type A.
Collapse
Affiliation(s)
- Sébastien Brier
- Biological NMR Technological Platform, Institut Pasteur, CNRS UMR3528, Paris, France
| | | | - Anne Wijkhuisen
- Département Médicaments et Technologies pour la santé, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Stéphanie Simon
- Département Médicaments et Technologies pour la santé, Université Paris-Saclay, CEA, INRAE, Gif-sur-Yvette, France
| | - Maud Marechal
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
| | - Emmanuel Lemichez
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
| | - Michel R Popoff
- Institut Pasteur, Unité des Toxines Bactériennes, UMR CNRS 2001, Paris, France
| |
Collapse
|
14
|
Safety, Tolerability, and Pharmacokinetics of NTM-1632, a Novel Mixture of Three Monoclonal Antibodies against Botulinum Toxin B. Antimicrob Agents Chemother 2021; 65:e0232920. [PMID: 33875433 PMCID: PMC8218613 DOI: 10.1128/aac.02329-20] [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] [Indexed: 01/17/2023] Open
Abstract
Botulism is a rare, life-threatening paralytic disease caused by Clostridium botulinum neurotoxin (BoNT). Available treatments, including an equine antitoxin and human immune globulin, are given postexposure and challenging to produce and administer. NTM-1632 is an equimolar mixture of 3 human IgG monoclonal antibodies, B1, B2, and B3, targeting BoNT serotype B (BoNT/B). This first-in-human study assessed the safety, tolerability, pharmacokinetics (PK), and immunogenicity of NTM-1632. This double-blind, single-center, placebo-controlled dose escalation study randomized 3 cohorts of healthy volunteers to receive a single intravenous dose of NTM-1632 (0.033, 0.165, or 0.330 mg/kg) or saline placebo. Safety monitoring included physical examinations, clinical laboratory studies, and vital signs. Blood sampling was performed at prespecified time points for PK and immunogenicity analyses. Twenty-four subjects received study product (18 NTM-1632; 6 placebo), and no deaths or serious adverse events were reported. Adverse events in the NTM-1632 groups were generally mild and similar in frequency and severity to the placebo group, and no safety signal was identified. NTM-1632 has a favorable PK profile with a half-life of >20 days for the 0.330-mg/kg dose and an approximately linear relationship with respect to maximum concentration and area under the concentration-time curve (AUC0→t). NTM-1632 demonstrated low immunogenicity with only a few treatment-emergent antidrug antibody responses in the low and middle dosing groups and none at the highest dose. NTM-1632 is well tolerated at the administered doses. The favorable safety, PK, and immunogenicity profile of NTM-1632 supports further clinical development as a treatment for BoNT/B intoxication and postexposure prophylaxis. (This study has been registered at ClinicalTrials.gov under identifier NCT02779140.).
Collapse
|
15
|
Structural Insights into Rational Design of Single-Domain Antibody-Based Antitoxins against Botulinum Neurotoxins. Cell Rep 2021; 30:2526-2539.e6. [PMID: 32101733 PMCID: PMC7138525 DOI: 10.1016/j.celrep.2020.01.107] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/23/2019] [Accepted: 01/30/2020] [Indexed: 12/12/2022] Open
Abstract
Botulinum neurotoxin (BoNT) is one of the most acutely lethal toxins known to humans, and effective treatment for BoNT intoxication is urgently needed. Single-domain antibodies (VHH) have been examined as a countermeasure for BoNT because of their high stability and ease of production. Here, we investigate the structures and the neutralization mechanisms for six unique VHHs targeting BoNT/A1 or BoNT/B1. These studies reveal diverse neutralizing mechanisms by which VHHs prevent host receptor binding or block transmembrane delivery of the BoNT protease domain. Guided by this knowledge, we design heterodimeric VHHs by connecting two neutralizing VHHs via a flexible spacer so they can bind simultaneously to the toxin. These bifunctional VHHs display much greater potency in a mouse co-intoxication model than similar heterodimers unable to bind simultaneously. Taken together, our studies offer insight into antibody neutralization of BoNTs and advance our ability to design multivalent anti-pathogen VHHs with improved therapeutic properties. Botulinum neurotoxins (BoNTs) are extremely toxic biothreats. Lam et al. report the crystal structures and neutralizing mechanisms of six unique antitoxin VHHs against BoNT/A1 and BoNT/B1, the two major human pathogenic BoNTs. They then develop a platform for structure-based rational design of bifunctional VHH heterodimers with superior antitoxin potencies.
Collapse
|
16
|
McNutt PM, Vazquez-Cintron EJ, Tenezaca L, Ondeck CA, Kelly KE, Mangkhalakhili M, Machamer JB, Angeles CA, Glotfelty EJ, Cika J, Benjumea CH, Whitfield JT, Band PA, Shoemaker CB, Ichtchenko K. Neuronal delivery of antibodies has therapeutic effects in animal models of botulism. Sci Transl Med 2021; 13:eabd7789. [PMID: 33408188 PMCID: PMC8176400 DOI: 10.1126/scitranslmed.abd7789] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/20/2020] [Indexed: 11/02/2022]
Abstract
Botulism is caused by a potent neurotoxin that blocks neuromuscular transmission, resulting in death by asphyxiation. Currently, the therapeutic options are limited and there is no antidote. Here, we harness the structural and trafficking properties of an atoxic derivative of botulinum neurotoxin (BoNT) to transport a function-blocking single-domain antibody into the neuronal cytosol where it can inhibit BoNT serotype A (BoNT/A1) molecular toxicity. Post-symptomatic treatment relieved toxic signs of botulism and rescued mice, guinea pigs, and nonhuman primates after lethal BoNT/A1 challenge. These data demonstrate that atoxic BoNT derivatives can be harnessed to deliver therapeutic protein moieties to the neuronal cytoplasm where they bind and neutralize intracellular targets in experimental models. The generalizability of this platform might enable delivery of antibodies and other protein-based therapeutics to previously inaccessible intraneuronal targets.
Collapse
Affiliation(s)
- Patrick M McNutt
- Wake Forest School of Medicine, Wake Forest Institute for Regenerative Medicine, Winston-Salem, NC 27101, USA
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Edwin J Vazquez-Cintron
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
- City College of City University of New York, NY 10031, USA
| | - Luis Tenezaca
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
| | - Celinia A Ondeck
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Kyle E Kelly
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Mark Mangkhalakhili
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - James B Machamer
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Christopher A Angeles
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Elliot J Glotfelty
- United States Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA
| | - Jaclyn Cika
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | - Cesar H Benjumea
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
| | | | - Philip A Band
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA
- CytoDel Inc., New York, NY 10016, USA
- Department of Orthopaedic Surgery, New York University Langone Orthopedic Hospital, New York, NY 10016, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA.
| |
Collapse
|
17
|
A Monoclonal Antibody Combination against both Serotypes A and B Botulinum Toxin Prevents Inhalational Botulism in a Guinea Pig Model. Toxins (Basel) 2021; 13:toxins13010031. [PMID: 33466411 PMCID: PMC7824882 DOI: 10.3390/toxins13010031] [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: 11/13/2020] [Revised: 12/23/2020] [Accepted: 12/29/2020] [Indexed: 12/28/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are extremely potent and can induce respiratory failure, requiring long-term intensive care to prevent death. Recombinant monoclonal antibodies (mAbs) hold considerable promise as BoNT therapeutics and prophylactics. In contrast, equine antitoxin cannot be used prophylactically and has a short half-life. Two three-mAb combinations are in development that specifically neutralize BoNT serotype A (BoNT/A) and B (BoNT/B). The three-mAb combinations addressing a single serotype provided pre-exposure prophylaxis in the guinea pig inhalation model. A lyophilized co-formulation of six mAbs, designated G03-52-01, that addresses both A and B serotypes is in development. Here, we investigated the efficacy of G03-52-01 to protect guinea pigs against an aerosol exposure challenge of BoNT/A1 or BoNT/B1. Previously, it was found that each antibody demonstrated a dose-dependent exposure and reached maximum circulating concentrations within 48 h after intramuscular (IM) or intravenous (IV) injection. Here we show that G03-52-01, in a single IM injection of G03-52-01 administered 48 h pre-exposure, protected guinea pigs against an aerosol challenge of up to 238 LD50s of BoNT/A1 and 191 LD50s of BoNT/B1. These data suggest that a single IM administration of G03-52-01 provides pre-exposure prophylaxis against botulism from an aerosol exposure of BoNT/A1 or BoNT/B1.
Collapse
|
18
|
Tremblay JM, Vazquez-Cintron E, Lam KH, Mukherjee J, Bedenice D, Ondeck CA, Conroy MT, Bodt SML, Winner BM, Webb RP, Ichtchenko K, Jin R, McNutt PM, Shoemaker CB. Camelid VHH Antibodies that Neutralize Botulinum Neurotoxin Serotype E Intoxication or Protease Function. Toxins (Basel) 2020; 12:toxins12100611. [PMID: 32987745 PMCID: PMC7598594 DOI: 10.3390/toxins12100611] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/02/2020] [Accepted: 09/11/2020] [Indexed: 12/12/2022] Open
Abstract
Botulinum neurotoxin (BoNT) serotype E is one of three serotypes that cause the preponderance of human botulism cases and is a Tier 1 Select Agent. BoNT/E is unusual among BoNT serotypes for its rapid onset and short duration of intoxication. Here we report two large panels of unique, unrelated camelid single-domain antibodies (VHHs) that were selected for their ability to bind to BoNT/E holotoxin and/or to the BoNT/E light chain protease domain (LC/E). The 19 VHHs which bind to BoNT/E were characterized for their subunit specificity and 8 VHHs displayed the ability to neutralize BoNT/E intoxication of neurons. Heterodimer antitoxins consisting of two BoNT/E-neutralizing VHHs, including one heterodimer designed using structural information for simultaneous binding, were shown to protect mice against co-administered toxin challenges of up to 500 MIPLD50. The 22 unique VHHs which bind to LC/E were characterized for their binding properties and 9 displayed the ability to inhibit LC/E protease activity. Surprisingly, VHHs selected on plastic-coated LC/E were virtually unable to recognize soluble or captured LC/E while VHHs selected on captured LC/E were poorly able to recognize LC/E coated to a plastic surface. This panel of anti-LC/E VHHs offer insight into BoNT/E function, and some may have value as components of therapeutic antidotes that reverse paralysis following BoNT/E exposures.
Collapse
Affiliation(s)
- Jacqueline M. Tremblay
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
| | - Edwin Vazquez-Cintron
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Kwok-Ho Lam
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697-4560, USA; (K.-H.L.); (R.J.)
| | - Jean Mukherjee
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
| | - Daniela Bedenice
- Department of Clinical Sciences, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA;
| | - Celinia A. Ondeck
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Matthieu T. Conroy
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Skylar M. L. Bodt
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Brittany M. Winner
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Robert P. Webb
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases, Ft. Detrick, MD 21702-5011, USA;
| | - Konstantin Ichtchenko
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY 10016, USA;
| | - Rongsheng Jin
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697-4560, USA; (K.-H.L.); (R.J.)
| | - Patrick M. McNutt
- The United States Army Medical Research Institute of Chemical Defense, Fort Detrick, MD 21010, USA; (E.V.-C.); (C.A.O.); (M.T.C.); (S.M.L.B.); (B.M.W.); (P.M.M.)
| | - Charles B. Shoemaker
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA; (J.M.T.); (J.M.)
- Correspondence:
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Larbouret C, Poul MA, Chardès T. [Mimicking polyclonal immune response in therapy: from combination of two monoclonal antibodies to oligoclonal antibody-based mixtures]. Med Sci (Paris) 2020; 35:1083-1091. [PMID: 31903921 DOI: 10.1051/medsci/2019216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Monoclonal antibodies have revolutionized the treatment of many diseases, but their clinical effectiveness remains limited in some cases. Associations of antibodies binding to the same target (homo-combination) or to several different targets (hetero-combination), thereby mimicking a polyclonal humoral immune response, have demonstrated a therapeutic improvement in pre-clinical and clinical trials, mainly in the field of oncology and infectious diseases. The combinations increase the efficacy of the biological responses and override resistance mechanisms observed with antibody monotherapy. The most common method of formulating and administering antibody combinations is a separate formulation, with sequential injection of each antibody as individual drug substance. Alternatively, combined formulations are developed where the separately-produced antibodies are mixed before administration or produced simultaneously by a single cell line, or a mixture of cell lines as a polyclonal master cell bank. The regulation, the toxicity and the injection sequence of these oligoclonal antibody-based mixtures remain points to be clarified and optimized for a better therapeutic effect.
Collapse
Affiliation(s)
- Christel Larbouret
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut régional du Cancer de Montpellier (ICM), 34298 Montpellier, France
| | - Marie-Alix Poul
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut régional du Cancer de Montpellier (ICM), 34298 Montpellier, France
| | - Thierry Chardès
- Institut de Recherche en Cancérologie de Montpellier (IRCM), Inserm U1194, Université de Montpellier, Institut régional du Cancer de Montpellier (ICM), 34298 Montpellier, France - Centre National de la Recherche Scientifique (CNRS), Paris, France
| |
Collapse
|
21
|
The Novel Clostridial Neurotoxin Produced by Strain IBCA10-7060 Is Immunologically Equivalent to BoNT/HA. Toxins (Basel) 2019; 12:toxins12010009. [PMID: 31877649 PMCID: PMC7020490 DOI: 10.3390/toxins12010009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/07/2019] [Accepted: 12/12/2019] [Indexed: 11/16/2022] Open
Abstract
Background: Botulinum neurotoxins (BoNTs) comprise seven agreed-on serotypes, A through G. In 2014, a novel chimeric neurotoxin produced by clostridial strain IBCA10-7060 was reported as BoNT/H, with subsequent names of BoNT/FA or BoNT/HA based on sequence homology of the N-terminus to BoNT/F, the C-terminus to BoNT/A and neutralization studies. The purpose of this study was to define the immunologic identity of the novel BoNT. Methods: monoclonal antibodies (mAbs) to the novel BoNT/H N-terminus were generated by antibody repertoire cloning and yeast display after immunization with BoNT/H LC-HN or BoNT/F LC-HN. Results: 21 unique BoNT/H LC-HN mAbs were obtained; 15 from the BoNT/H LC-HN immunized library (KD 0.78 nM to 182 nM) and six from the BoNT/F-immunized libraries (KD 20.5 nM to 1490 nM). A total of 15 of 21 mAbs also bound catalytically inactive BoNT/H holotoxin. The mAbs bound nine non-overlapping epitopes on the BoNT/H LC-HN. None of the mAbs showed binding to BoNT serotypes A-G, nor any of the seven subtypes of BoNT/F, except for one mAb that weakly bound BoNT/F5. Conclusions: The results, combined with the chimeric structure and neutralization by anti-A, but not anti-F antitoxin indicate that immunologically the novel BoNT is BoNT/HA. This determination has significant implications for existing countermeasures and potential vulnerabilities.
Collapse
|
22
|
Safety and Pharmacokinetics of a Four Monoclonal Antibody Combination Against Botulinum C and D Neurotoxins. Antimicrob Agents Chemother 2019:AAC.01270-19. [PMID: 31591130 PMCID: PMC6879217 DOI: 10.1128/aac.01270-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Botulism is caused by botulinum neurotoxin (BoNT), the most poisonous substance known. BoNTs are also classified as Tier 1 biothreat agents due to their high potency and lethality. The existence of seven BoNT serotypes (A-G), which differ between 35% to 68% in amino acid sequence, necessitates the development of serotype specific countermeasures. We present results of a Phase 1 clinical study of an anti-toxin to BoNT serotypes C and D, NTM-1634, which consists of an equimolar mixture of four fully human IgG1 monoclonal antibodies (mAbs), each binding to non-overlapping epitopes on BoNT serotypes C and D resulting in potent toxin neutralization in rodents. This first-in-human study evaluated the safety and pharmacokinetics of escalating doses of NTM-1634 administered intravenously to healthy adults (NCT03046550). Three cohorts of eight healthy subjects received a single intravenous dose of NTM-1634 or placebo at 0.33 mg/kg, 0.66 mg/kg or 1 mg/kg. Follow-up examinations and pharmacokinetic evaluations were continued up to 121 days post-infusion. Subjects were monitored using physical examinations, hematology and chemistry blood tests, and electrocardiograms. Pharmacokinetic parameters were estimated using noncompartmental methods. The results demonstrated that the materials were safe and well-tolerated with the expected half-lives for human mAbs and with minimal anti-drug antibodies detected over the dose ranges and duration of the study.
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Randomized, Double-Blind, Placebo-Controlled, Single-Ascending-Dose Study of the Penetration of a Monoclonal Antibody Combination (ASN100) Targeting Staphylococcus aureus Cytotoxins in the Lung Epithelial Lining Fluid of Healthy Volunteers. Antimicrob Agents Chemother 2019; 63:AAC.00350-19. [PMID: 31138568 PMCID: PMC6658777 DOI: 10.1128/aac.00350-19] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 05/13/2019] [Indexed: 12/18/2022] Open
Abstract
ASN100 is a novel antibody combination of two fully human IgG1(κ) monoclonal antibodies (MAbs), ASN-1 and ASN-2, which neutralize six Staphylococcus aureus cytotoxins, alpha-hemolysin (Hla) and five bicomponent leukocidins. We assessed the safety, tolerability, and serum and lung pharmacokinetics of ASN100 in a randomized, double-blind, placebo-controlled single-dose-escalation first-in-human study. ASN100 is a novel antibody combination of two fully human IgG1(κ) monoclonal antibodies (MAbs), ASN-1 and ASN-2, which neutralize six Staphylococcus aureus cytotoxins, alpha-hemolysin (Hla) and five bicomponent leukocidins. We assessed the safety, tolerability, and serum and lung pharmacokinetics of ASN100 in a randomized, double-blind, placebo-controlled single-dose-escalation first-in-human study. Fifty-two healthy volunteers were enrolled and randomized to receive either ASN-1, ASN-2, a combination of both MAbs (ASN100), or a corresponding placebo. Thirty-two subjects in the double-blind dose escalation portion of the study received ASN-1 or ASN-2 at a 200-, 600-, 1,800-, or 4,000-mg dose, or placebo. Eight subjects received both MAbs simultaneously in a 1:1 ratio (ASN100) at 3,600 or 8,000 mg, or they received placebos. Twelve additional subjects received open-label ASN100 at 3,600 or 8,000 mg to assess the pharmacokinetics of ASN-1 and ASN-2 in epithelial lining fluid (ELF) by bronchoalveolar lavage fluid sampling. Subjects were monitored for 98 days (double-blind cohorts) or 30 days (open-label cohorts) for safety assessment. No dose-limiting toxicities were observed, and all adverse events were mild and transient, with only two adverse events considered possibly related to the investigational product. ASN100 exhibited linear serum pharmacokinetics with a half-life of approximately 3 weeks and showed detectable penetration into the ELF. No treatment-emergent anti-drug antibody responses were detected. The toxin neutralizing potency of ASN100 in human serum was confirmed up to 58 days postdosing. The favorable safety profile, ELF penetration, and maintained functional activity in serum supported the further clinical development of ASN100.
Collapse
|
25
|
Pharmacokinetics of Human Recombinant Anti-Botulinum Toxin Antibodies in Rats. Toxins (Basel) 2019; 11:toxins11060345. [PMID: 31212950 PMCID: PMC6628388 DOI: 10.3390/toxins11060345] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/02/2019] [Accepted: 06/03/2019] [Indexed: 12/18/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are potential biothreat agents due to their high lethality, potency, and ease of distribution, thus the development of antitoxins is a high priority to the US government. This study examined pre-clinical pharmacokinetic studies in rats of four oligoclonal anti-BoNT mAb-based therapeutics (NTM-1631, NTM-1632, NTM-1633, NTM-1634) for five BoNT serotypes (A, B, E, C, and D). NTM-1631, NTM-1632, and NTM-1633 each consist of three IgG1 mAbs, each with a distinct human or humanized variable region which bind to distinct epitopes on BoNT serotype A, B, or E respectively. NTM-1634 consists of four human immunoglobulin G1 (IgG1) mAbs binding BoNT C/D mosaic toxins. The mechanism of these antitoxins requires that three antibodies simultaneously bind toxin to achieve rapid clearance. Rats (total 378) displayed no adverse clinical signs attributed to antibody treatment from any of the antitoxins. Pharmacokinetic evaluation demonstrated that the individual mAbs are slowly eliminated, exhibiting dose-dependent exposure and long elimination half-lives ranging from 6.5 days to 10 days. There were no consistent differences observed between males and females or among the individual antibodies in each formulation in half-life. Anti-drug antibodies (ADA) were observed, as expected for human antibodies administered to rats. The results presented were used to support the clinical investigation of antibody-based botulism antitoxins.
Collapse
|
26
|
Monoclonal Antibody Combinations Prevent Serotype A and Serotype B Inhalational Botulism in a Guinea Pig Model. Toxins (Basel) 2019; 11:toxins11040208. [PMID: 30959899 PMCID: PMC6520708 DOI: 10.3390/toxins11040208] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/29/2019] [Accepted: 03/30/2019] [Indexed: 11/16/2022] Open
Abstract
Botulinum neurotoxins (BoNT) are some of the most toxic proteins known, with a human LD50 of ~1 ng/kg. Equine antitoxin has a half-life in circulation of less than 1 day and is limited to a treatment rather than a prevention indication. The development of monoclonal antibodies (mAbs) may represent an alternative therapeutic option that can be produced at high quantities and of high quality and with half-lives of >10 days. Two different three mAb combinations are being developed that specifically neutralize BoNT serotypes A (BoNT/A) and B (BoNT/B). We investigated the pharmacokinetics of the anti-BoNT/A and anti-BoNT/B antibodies in guinea pigs (Cavia porcellus) and their ability to protect guinea pigs against an aerosol challenge of BoNT/A1 or BoNT/B1. Each antibody exhibited dose-dependent exposure and reached maximum circulating concentrations within 48 h post intraperitoneal or intramuscular injection. A single intramuscular dose of the three mAb combination protected guinea pigs against an aerosol challenge dose of 93 LD50 of BoNT/A1 and 116 LD50 of BoNT/B1 at 48 h post antibody administration. These mAbs are effective in preventing botulism after an aerosol challenge of BoNT/A1 and BoNT/B1 and may represent an alternative to vaccination to prevent type A or B botulism in those at risk of BoNT exposure.
Collapse
|
27
|
Natural Compounds and Their Analogues as Potent Antidotes against the Most Poisonous Bacterial Toxin. Appl Environ Microbiol 2018; 84:AEM.01280-18. [PMID: 30389764 DOI: 10.1128/aem.01280-18] [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: 05/31/2018] [Accepted: 09/28/2018] [Indexed: 01/30/2023] Open
Abstract
Botulinum neurotoxins (BoNTs), the most poisonous proteins known to humankind, are a family of seven (serotype A to G) immunologically distinct proteins synthesized primarily by different strains of the anaerobic bacterium Clostridium botulinum Being the causative agents of botulism, the toxins block neurotransmitter release by specifically cleaving one of the three soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins, thereby inducing flaccid paralysis. The development of countermeasures and therapeutics against BoNTs is a high-priority research area for public health because of their extreme toxicity and potential for use as biowarfare agents. Extensive research has focused on designing antagonists that block the catalytic activity of BoNTs. In this study, we screened 300 small natural compounds and their analogues extracted from Indian plants for their activity against BoNT serotype A (BoNT/A) as well as its light chain (LCA) using biochemical and cellular assays. One natural compound, a nitrophenyl psoralen (NPP), was identified to be a specific inhibitor of LCA with an in vitro 50% inhibitory concentration (IC50) value of 4.74 ± 0.03 µM. NPP was able to rescue endogenous synaptosome-associated protein 25 (SNAP-25) from cleavage by BoNT/A in human neuroblastoma cells with an IC50 of 12.2 ± 1.7 µM, as well as to prolong the time to the blocking of neutrally elicited twitch tensions in isolated mouse phrenic nerve-hemidiaphragm preparations.IMPORTANCE The long-lasting endopeptidase activity of BoNT is a critical biological activity inside the nerve cell, as it prompts proteolysis of the SNARE proteins, involved in the exocytosis of the neurotransmitter acetylcholine. Thus, the BoNT endopeptidase activity is an appropriate clinical target for designing new small-molecule antidotes against BoNT with the potential to reverse the paralysis syndrome of botulism. In principle, small-molecule inhibitors (SMIs) can gain entry into BoNT-intoxicated cells if they have a suitable octanol-water partition coefficient (log P) value and other favorable characteristics (P. Leeson, Nature 481:455-456, 2012, https://doi.org/10.1038/481455a). Several efforts have been made in the past to develop SMIs, but inhibitors effective under in vitro conditions have not in general been effective in vivo or in cellular models (L. M. Eubanks, M. S. Hixon, W. Jin, S. Hong, et al., Proc Natl Acad Sci U S A 104:2602-2607, 2007, https://doi.org/10.1073/pnas.0611213104). The difference between the in vitro and cellular efficacy presumably results from difficulties experienced by the compounds in crossing the cell membrane, in conjunction with poor bioavailability and high cytotoxicity. The screened nitrophenyl psoralen (NPP) effectively antagonized BoNT/A in both in vitro and ex vivo assays. Importantly, NPP inhibited the BoNT/A light chain but not other general zinc endopeptidases, such as thermolysin, suggesting high selectivity for its target. Small-molecule (nonpeptidic) inhibitors have better oral bioavailability, better stability, and better tissue and cell permeation than antitoxins or peptide inhibitors.
Collapse
|
28
|
Wijesuriya SD, Pongo E, Tomic M, Zhang F, Garcia-Rodriquez C, Conrad F, Farr-Jones S, Marks JD, Horwitz AH. Antibody engineering to improve manufacturability. Protein Expr Purif 2018; 149:75-83. [DOI: 10.1016/j.pep.2018.04.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 04/04/2018] [Indexed: 10/17/2022]
|
29
|
Nagy E, Nagy G, Power CA, Badarau A, Szijártó V. Anti-bacterial Monoclonal Antibodies. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1053:119-153. [PMID: 29549638 DOI: 10.1007/978-3-319-72077-7_7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The failing efficacy of antibiotics and the high mortality rate among high-risk patients calls for new treatment modalities for bacterial infections. Due to the vastly divergent pathogenesis of human pathogens, each microbe requires a tailored approach. The main modes of action of anti-bacterial antibodies are virulence factor neutralization, complement-mediated bacterial lysis and enhancement of opsonophagocytic uptake and killing (OPK). Gram-positive bacteria cannot be lysed by complement and their pathogenesis often involves secreted toxins, therefore typically toxin-neutralization and OPK activity are required to prevent and ameliorate disease. In fact, the success stories in terms of approved products, in the anti-bacterial mAb field are based on toxin neutralization (Bacillus anthracis, Clostridium difficile). In contrast, Gram-negative bacteria are vulnerable to antibody-dependent complement-mediated lysis, while their pathogenesis rarely relies on secreted exotoxins, and involves the pro-inflammatory endotoxin (lipopolysaccharide). Given the complexity of bacterial pathogenesis, antibody therapeutics are expected to be most efficient upon targeting more than one virulence factor and/or combining different modes of action. The improved understanding of bacterial pathogenesis combined with the versatility and maturity of antibody discovery technologies available today are pivotal for the design of novel anti-bacterial therapeutics. The intensified research generating promising proof-of-concept data, and the increasing number of clinical programs with anti-bacterial mAbs, indicate that the field is ready to fulfill its promise in the coming years.
Collapse
Affiliation(s)
- Eszter Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria.
| | - Gábor Nagy
- Arsanis Biosciences GmbH/Arsanis, Inc, Vienna, Austria
| | | | | | | |
Collapse
|
30
|
Li M, Lee D, Obi CR, Freeberg JK, Farr-Jones S, Tomic MT. An ambient temperature-stable antitoxin of nine co-formulated antibodies for botulism caused by serotypes A, B and E. PLoS One 2018; 13:e0197011. [PMID: 29746518 PMCID: PMC5944936 DOI: 10.1371/journal.pone.0197011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 04/24/2018] [Indexed: 12/11/2022] Open
Abstract
Safe and effective antitoxins to treat and prevent botulism are needed for biodefense. We have developed recombinant antibody-based therapeutics for botulinum neurotoxin (BoNT) serotypes A, B, and E. The mechanism of action of this antitoxin requires that three mAbs bind one toxin molecule to achieve clearance. Here we present a co-formulation of an antitoxin to the three most important serotypes. Combining these antibodies obviates the need to identify the serotype causing intoxication prior to drug administration, which would facilitate administration. The lyophilized powder formulation contains nine mAbs, three mAbs for each of the three serotypes (A, B, E). The formulation was stored as a liquid and lyophilized powder for up to one year, and characterized by binding affinity and multiple physicochemical methods. No significant increase in soluble higher order aggregates, cleavage products, or change in charge isoforms was measured after storage as a lyophilized powder at 50°C for one year. Furthermore, toxin-domain binding ELISA data indicated that each of the individual antibodies in the lyophilized drug product showed essentially full binding capability to their respective toxin domains after being stored at 50°C for one year. Physicochemical characterization of the formulation demonstrated the nine individual mAbs were remarkably stable. This work demonstrates feasibility of lyophilized, oligoclonal antibody therapies for biodefense with ambient temperature stability, that would facilitate stockpiling, distribution, and administration.
Collapse
Affiliation(s)
- Mingxiang Li
- XOMA Corp., Berkeley, CA, United States of America
| | - Dennis Lee
- XOMA Corp., Berkeley, CA, United States of America
| | - Chidi R. Obi
- XOMA Corp., Berkeley, CA, United States of America
| | | | - Shauna Farr-Jones
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, San Francisco, CA, United States of America
| | - Milan T. Tomic
- XOMA Corp., Berkeley, CA, United States of America
- * E-mail:
| |
Collapse
|
31
|
A Three Monoclonal Antibody Combination Potently Neutralizes Multiple Botulinum Neurotoxin Serotype E Subtypes. Toxins (Basel) 2018; 10:toxins10030105. [PMID: 29494481 PMCID: PMC5869393 DOI: 10.3390/toxins10030105] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 11/26/2022] Open
Abstract
Human botulism is most commonly caused by botulinum neurotoxin (BoNT) serotypes A, B, and E. For this work, we sought to develop a human monoclonal antibody (mAb)-based antitoxin capable of binding and neutralizing multiple subtypes of BoNT/E. Libraries of yeast-displayed single chain Fv (scFv) antibodies were created from the heavy and light chain variable region genes of humans immunized with pentavalent-toxoid- and BoNT/E-binding scFv isolated by Fluorescence-Activated Cell Sorting (FACS). A total of 10 scFv were isolated that bound one or more BoNT/E subtypes with nanomolar-level equilibrium dissociation constants (KD). By diversifying the V-regions of the lead mAbs and selecting for cross-reactivity, we generated three scFv that bound all four BoNT/E subtypes tested at three non-overlapping epitopes. The scFvs were converted to IgG that had KD values for the different BoNT/E subtypes ranging from 9.7 nM to 2.28 pM. An equimolar combination of the three mAbs was able to potently neutralize BoNT/E1, BoNT/E3, and BoNT/E4 in a mouse neutralization assay. The mAbs have potential utility as therapeutics and as diagnostics capable of recognizing multiple BoNT/E subtypes. A derivative of the three-antibody combination (NTM-1633) is in pre-clinical development with an investigational new drug (IND) application filing expected in 2018.
Collapse
|
32
|
A Single Tri-Epitopic Antibody Virtually Recapitulates the Potency of a Combination of Three Monoclonal Antibodies in Neutralization of Botulinum Neurotoxin Serotype A. Toxins (Basel) 2018; 10:toxins10020084. [PMID: 29462889 PMCID: PMC5848185 DOI: 10.3390/toxins10020084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 02/05/2018] [Accepted: 02/13/2018] [Indexed: 11/17/2022] Open
Abstract
The standard of treatment for botulism, equine antitoxin, is a foreign protein with associated safety issues and a short serum half-life which excludes its use as a prophylactic antitoxin and makes it a less-than-optimal therapeutic. Due to these limitations, a recombinant monoclonal antibody (mAb) product is preferable. It has been shown that combining three mAbs that bind non-overlapping epitopes leads to highly potent botulinum neurotoxin (BoNT) neutralization. Recently, a triple human antibody combination for BoNT/A has demonstrated potent toxin neutralization in mouse models with no serious adverse events when tested in a Phase I clinical trial. However, a triple antibody therapeutic poses unique development and manufacturing challenges. Thus, potentially to streamline development of BoNT antitoxins, we sought to achieve the potency of multiple mAb combinations in a single IgG-based molecule that has a long serum half-life. The design, production, and testing of a single tri-epitopic IgG1-based mAb (TeAb) containing the binding sites of each of the three parental BoNT/A mAbs yielded an antibody of nearly equal potency to the combination. The approach taken here could be applied to the design and creation of other multivalent antibodies that could be used for a variety of applications, including toxin elimination.
Collapse
|
33
|
Carter PJ, Lazar GA. Next generation antibody drugs: pursuit of the 'high-hanging fruit'. Nat Rev Drug Discov 2017; 17:197-223. [DOI: 10.1038/nrd.2017.227] [Citation(s) in RCA: 447] [Impact Index Per Article: 63.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
34
|
Yu J, Wang X, Xu T, Jin Q, Duan J, Wu J, Wu H, Xu T, Ye S. A rational approach to enhancing antibody Fc homodimer formation for robust production of antibody mixture in a single cell line. J Biol Chem 2017; 292:17885-17896. [PMID: 28878018 DOI: 10.1074/jbc.m116.771188] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 08/19/2017] [Indexed: 11/06/2022] Open
Abstract
Combinations of different antibodies have been shown to be more effective for managing certain diseases than monotherapy. Co-expression of the antibody mixture in a single cell line is key to reducing complexity during antibody development and manufacturing. However, co-transfection of multiple light and heavy chains into cells often leads to production of mismatched, heterodimeric by-products that are inactive, making the development of co-expression systems that robustly and efficiently produce highly active antibody mixtures a high priority. In this study, we modified the CH3 domain interface of the antibody fragment crystallizable (Fc) region by changing several charge pairs to create electrostatic interactions favoring Fc homodimer formation and disfavoring Fc heterodimer formation. When co-expressed, these modified antibodies with altered charge polarity across the Fc dimer interface preferentially formed homodimers that fully preserved the functions of each component, rather than inactive heterodimers whose formation was reduced because of rationally designed repulsive interactions. We designed eight different combinations and experimentally screened the best one, which enabled us to produce a binary antibody mixture against the EGF receptor with a minimal heterodimer contaminant. We further determined the crystal structure of a triple-mutated Fc variant in the best combination, and we elucidated the molecular interactions favoring Fc homodimer over heterodimer formation, which provided a structural basis for further optimization. The approach presented here demonstrates the feasibility of rational antibody modification for efficient and consistent production of monoclonal antibody mixtures in a single cell line and thus broadens our options for manufacturing more effective antibody-based therapeutic agents.
Collapse
Affiliation(s)
- Jie Yu
- From the Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 and
| | | | - Tao Xu
- Alphamab Co. Ltd., Suzhou 215125, China
| | - Qiuheng Jin
- From the Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 and
| | - Jinyuan Duan
- From the Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 and
| | - Jie Wu
- Alphamab Co. Ltd., Suzhou 215125, China
| | - Haiyan Wu
- Alphamab Co. Ltd., Suzhou 215125, China
| | - Ting Xu
- Alphamab Co. Ltd., Suzhou 215125, China
| | - Sheng Ye
- From the Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058 and
| |
Collapse
|
35
|
Genetically engineered red cells expressing single domain camelid antibodies confer long-term protection against botulinum neurotoxin. Nat Commun 2017; 8:423. [PMID: 28871080 PMCID: PMC5583347 DOI: 10.1038/s41467-017-00448-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 06/08/2017] [Indexed: 12/12/2022] Open
Abstract
A short half-life in the circulation limits the application of therapeutics such as single-domain antibodies (VHHs). We utilize red blood cells to prolong the circulatory half-life of VHHs. Here we present VHHs against botulinum neurotoxin A (BoNT/A) on the surface of red blood cells by expressing chimeric proteins of VHHs with Glycophorin A or Kell. Mice whose red blood cells carry the chimeric proteins exhibit resistance to 10,000 times the lethal dose (LD50) of BoNT/A, and transfusion of these red blood cells into naive mice affords protection for up to 28 days. We further utilize an improved CD34+ culture system to engineer human red blood cells that express these chimeric proteins. Mice transfused with these red blood cells are resistant to highly lethal doses of BoNT/A. We demonstrate that engineered red blood cells expressing VHHs can provide prolonged prophylactic protection against bacterial toxins without inducing inhibitory immune responses and illustrates the potentially broad translatability of our strategy for therapeutic applications. The therapeutic use of single-chain antibodies (VHHs) is limited by their short half-life in the circulation. Here the authors engineer mouse and human red blood cells to express VHHs against botulinum neurotoxin A (BoNT/A) on their surface and show that an infusion of these cells into mice confers long lasting protection against a high dose of BoNT/A.
Collapse
|
36
|
Yao G, Lam KH, Weisemann J, Peng L, Krez N, Perry K, Shoemaker CB, Dong M, Rummel A, Jin R. A camelid single-domain antibody neutralizes botulinum neurotoxin A by blocking host receptor binding. Sci Rep 2017; 7:7438. [PMID: 28785006 PMCID: PMC5547058 DOI: 10.1038/s41598-017-07457-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 06/23/2017] [Indexed: 01/07/2023] Open
Abstract
Antibody treatment is currently the only available countermeasure for botulism, a fatal illness caused by flaccid paralysis of muscles due to botulinum neurotoxin (BoNT) intoxication. Among the seven major serotypes of BoNT/A-G, BoNT/A poses the most serious threat to humans because of its high potency and long duration of action. Prior to entering neurons and blocking neurotransmitter release, BoNT/A recognizes motoneurons via a dual-receptor binding process in which it engages both the neuron surface polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Previously, we identified a potent neutralizing antitoxin against BoNT/A1 termed ciA-C2, derived from a camelid heavy-chain-only antibody (VHH). In this study, we demonstrate that ciA-C2 prevents BoNT/A1 intoxication by inhibiting its binding to neuronal receptor SV2. Furthermore, we determined the crystal structure of ciA-C2 in complex with the receptor-binding domain of BoNT/A1 (HCA1) at 1.68 Å resolution. The structure revealed that ciA-C2 partially occupies the SV2-binding site on HCA1, causing direct interference of HCA1 interaction with both the N-glycan and peptide-moiety of SV2. Interestingly, this neutralization mechanism is similar to that of a monoclonal antibody in clinical trials, despite that ciA-C2 is more than 10-times smaller. Taken together, these results enlighten our understanding of BoNT/A1 interactions with its neuronal receptor, and further demonstrate that inhibiting toxin binding to the host receptor is an efficient countermeasure strategy.
Collapse
Affiliation(s)
- Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
| | - Kwok-Ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
| | - Jasmin Weisemann
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Lisheng Peng
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Nadja Krez
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, USA
| | - Charles B Shoemaker
- Department of Infectious Diseases and Global Health, Tufts Clinical and Translational Science Institute, North Grafton, Massachusetts, USA
| | - Min Dong
- Department of Urology, Boston Children's Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, USA.
| |
Collapse
|
37
|
Torgeman A, Ozeri E, Ben David A, Diamant E, Rosen O, Schwartz A, Barnea A, Makovitzki A, Mimran A, Zichel R. Role of Homologous Fc Fragment in the Potency and Efficacy of Anti-Botulinum Antibody Preparations. Toxins (Basel) 2017; 9:toxins9060180. [PMID: 28555060 PMCID: PMC5488030 DOI: 10.3390/toxins9060180] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 05/24/2017] [Accepted: 05/27/2017] [Indexed: 12/12/2022] Open
Abstract
The only approved treatment for botulism relies on passive immunity which is mostly based on antibody preparations collected from hyper-immune horses. The IgG Fc fragment is commonly removed from these heterologous preparations to reduce the incidence of hyper-sensitivity reactions. New-generation therapies entering the pipeline are based on a combination of humanized monoclonal antibodies (MAbs), which exhibit improved safety and pharmacokinetics. In the current study, a systematic and quantitative approach was applied to measure the direct contribution of homologous Fc to the potency of monoclonal and polyclonal antitoxin preparations in mice. Homologous Fc increased the potency of three individual anti-botulinum toxin MAbs by up to one order of magnitude. Moreover, Fc fragment removal almost completely abolished the synergistic potency obtained from a combined preparation of these three MAbs. The MAb mixture neutralized a 400-mouse median lethal dose (MsLD50) of botulinum toxin, whereas the F(ab′)2 combination failed to neutralize 10 MsLD50 of botulinum toxin. Notably, increased avidity did not compensate for this phenomenon, as a polyclonal, hyper-immune, homologous preparation lost 90% of its potency as well upon Fc removal. Finally, the addition of homologous Fc arms to a heterologous pharmaceutical anti-botulinum toxin polyclonal horse F(ab′)2 preparation improved its efficacy when administered to intoxicated symptomatic mice. Our study extends the aspects by which switching from animal-based to human-based antitoxins will improve not only the safety but also the potency and efficacy of passive immunity against toxins.
Collapse
Affiliation(s)
- Amram Torgeman
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Eyal Ozeri
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Alon Ben David
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Eran Diamant
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Osnat Rosen
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Arieh Schwartz
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Ada Barnea
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Arik Makovitzki
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Avishai Mimran
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| | - Ran Zichel
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 7410001, Israel.
| |
Collapse
|
38
|
A three monoclonal antibody combination potently neutralizes multiple botulinum neurotoxin serotype F subtypes. PLoS One 2017; 12:e0174187. [PMID: 28323873 PMCID: PMC5360321 DOI: 10.1371/journal.pone.0174187] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 03/04/2017] [Indexed: 11/19/2022] Open
Abstract
Human botulism is primarily caused by botulinum neurotoxin (BoNT) serotypes A, B and E, with around 1% caused by serotype F (BoNT/F). BoNT/F comprises at least seven different subtypes with the amino acid sequence difference between subtypes as high as 36%. The sequence differences present a significant challenge for generating monoclonal antibodies (mAbs) that can bind, detect and neutralize all BoNT/F subtypes. We used repertoire cloning of immune mouse antibody variable (V) regions and yeast display to generate a panel of 33 lead single chain Fv (scFv) mAbs that bound one or more BoNT/F subtypes with a median equilibrium dissociation constant (KD) of 4.06 × 10-9 M. By diversifying the V-regions of the lead mAbs and selecting for cross reactivity we generated five mAbs that bound each of the seven subtypes. Three scFv binding non-overlapping epitopes were converted to IgG that had KD for the different BoNT/F subtypes ranging from 2.2×10-8 M to 1.47×10-12 pM. An equimolar combination of the mAbs was able to potently neutralize BoNT/F1, F2, F4 and F7 in the mouse neutralization assay. The mAbs have potential utility as diagnostics capable of recognizing the known BoNT/F subtypes and could be developed as antitoxins to prevent and treat type F botulism.
Collapse
|
39
|
Yao G, Lam KH, Perry K, Weisemann J, Rummel A, Jin R. Crystal Structure of the Receptor-Binding Domain of Botulinum Neurotoxin Type HA, Also Known as Type FA or H. Toxins (Basel) 2017; 9:toxins9030093. [PMID: 28282873 PMCID: PMC5371848 DOI: 10.3390/toxins9030093] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/03/2017] [Accepted: 03/04/2017] [Indexed: 01/02/2023] Open
Abstract
Botulinum neurotoxins (BoNTs), which have been exploited as cosmetics and muscle-disorder treatment medicines for decades, are well known for their extreme neurotoxicity to humans. They pose a potential bioterrorism threat because they cause botulism, a flaccid muscular paralysis-associated disease that requires immediate antitoxin treatment and intensive care over a long period of time. In addition to the existing seven established BoNT serotypes (BoNT/A–G), a new mosaic toxin type termed BoNT/HA (aka type FA or H) was reported recently. Sequence analyses indicate that the receptor-binding domain (HC) of BoNT/HA is ~84% identical to that of BoNT/A1. However, BoNT/HA responds differently to some potent BoNT/A-neutralizing antibodies (e.g., CR2) that target the HC. Therefore, it raises a serious concern as to whether BoNT/HA poses a new threat to our biosecurity. In this study, we report the first high-resolution crystal structure of BoNT/HA-HC at 1.8 Å. Sequence and structure analyses reveal that BoNT/HA and BoNT/A1 are different regarding their binding to cell-surface receptors including both polysialoganglioside (PSG) and synaptic vesicle glycoprotein 2 (SV2). Furthermore, the new structure also provides explanations for the ~540-fold decreased affinity of antibody CR2 towards BoNT/HA compared to BoNT/A1. Taken together, these new findings advance our understanding of the structure and function of this newly identified toxin at the molecular level, and pave the way for the future development of more effective countermeasures.
Collapse
Affiliation(s)
- Guorui Yao
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
| | - Kwok-Ho Lam
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Building 436E, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA.
| | - Jasmin Weisemann
- Institut für Toxikologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Rongsheng Jin
- Department of Physiology & Biophysics, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
40
|
Yao G, Zhang S, Mahrhold S, Lam KH, Stern D, Bagramyan K, Perry K, Kalkum M, Rummel A, Dong M, Jin R. N-linked glycosylation of SV2 is required for binding and uptake of botulinum neurotoxin A. Nat Struct Mol Biol 2016; 23:656-62. [PMID: 27294781 PMCID: PMC5033645 DOI: 10.1038/nsmb.3245] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/13/2016] [Indexed: 02/01/2023]
Abstract
Botulinum neurotoxin serotype A1 (BoNT/A1), a licensed drug widely used for medical and cosmetic applications, exerts its action by invading motoneurons. Here we report a 2.0-Å-resolution crystal structure of the BoNT/A1 receptor-binding domain in complex with its neuronal receptor, glycosylated human SV2C. We found that the neuronal tropism of BoNT/A1 requires recognition of both the peptide moiety and an N-linked glycan on SV2. This N-glycan-which is conserved in all SV2 isoforms across vertebrates-is essential for BoNT/A1 binding to neurons and for its potent neurotoxicity. The glycan-binding interface on SV2 is targeted by a human BoNT/A1-neutralizing antibody currently licensed as an antibotulism drug. Our studies reveal a new paradigm of host-pathogen interactions, in which pathogens exploit conserved host post-translational modifications, thereby achieving highly specific receptor binding while also tolerating genetic changes across multiple isoforms of receptors.
Collapse
Affiliation(s)
- Guorui Yao
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
| | - Sicai Zhang
- Department of Urology, Boston Children’s Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Stefan Mahrhold
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Kwok-ho Lam
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
| | - Daniel Stern
- Centre for Biological Threats and Special Pathogens - Biological Toxins (ZBS3), Robert Koch-Institut, Berlin, Germany
| | - Karine Bagramyan
- Department of Molecular Immunology, Beckman Research Institute of City of Hope, Duarte, California USA
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois USA
| | - Markus Kalkum
- Department of Molecular Immunology, Beckman Research Institute of City of Hope, Duarte, California USA
| | - Andreas Rummel
- Institut für Toxikologie, Medizinische Hochschule Hannover, Hannover, Germany
| | - Min Dong
- Department of Urology, Boston Children’s Hospital, Department of Microbiology and Immunobiology and Department of Surgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Rongsheng Jin
- Department of Physiology and Biophysics, University of California, Irvine, California, USA
| |
Collapse
|
41
|
Corti D, Kearns JD. Promises and pitfalls for recombinant oligoclonal antibodies-based therapeutics in cancer and infectious disease. Curr Opin Immunol 2016; 40:51-61. [PMID: 26995095 PMCID: PMC7127534 DOI: 10.1016/j.coi.2016.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 02/08/2023]
Abstract
Monoclonal antibodies (mAbs) have revolutionized the diagnosis and treatment of many human diseases and the application of combinations of mAbs has demonstrated improved therapeutic activity in both preclinical and clinical testing. Combinations of antibodies have several advantages such as the capacities to target multiple and mutating antigens in complex pathogens and to engage varied epitopes on multiple disease-related antigens (e.g. receptors) to overcome heterogeneity and plasticity. Oligoclonal antibodies are an emerging therapeutic format in which a novel antibody combination is developed as a single drug product. Here, we will provide historical context on the use of oligoclonal antibodies in oncology and infectious diseases and will highlight practical considerations related to their preclinical and clinical development programs.
Collapse
Affiliation(s)
| | - Jeffrey D Kearns
- Merrimack Pharmaceuticals, Inc., One Kendall Square, Suite B7201, Cambridge, MA 02139, USA.
| |
Collapse
|
42
|
Fan Y, Barash JR, Lou J, Conrad F, Marks JD, Arnon SS. Immunological Characterization and Neutralizing Ability of Monoclonal Antibodies Directed Against Botulinum Neurotoxin Type H. J Infect Dis 2016; 213:1606-14. [PMID: 26936913 PMCID: PMC4837907 DOI: 10.1093/infdis/jiv770] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 12/19/2015] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Only Clostridium botulinum strain IBCA10-7060 produces the recently described novel botulinum neurotoxin type H (BoNT/H). BoNT/H (N-terminal two-thirds most homologous to BoNT/F and C-terminal one-third most homologous to BoNT/A) requires antitoxin to toxin ratios ≥1190:1 for neutralization by existing antitoxins. Hence, more potent and safer antitoxins against BoNT/H are needed. METHODS We therefore evaluated our existing monoclonal antibodies (mAbs) to BoNT/A and BoNT/F for BoNT/H binding, created yeast-displayed mutants to select for higher-affinity-binding mAbs by using flow cytometry, and evaluated the mAbs' ability to neutralize BoNT/H in the standard mouse bioassay. RESULTS Anti-BoNT/A HCC-binding mAbs RAZ1 and CR2 bound BoNT/H with high affinity. However, only 1 of 6 BoNT/F mAbs (4E17.2A) bound BoNT/H but with an affinity >800-fold lower (equilibrium dissociation binding constant [KD] = 7.56 × 10(-8)M) than its BoNT/F affinity (KD= 9.1 × 10(-11)M), indicating that the N-terminal two-thirds of BoNT/H is immunologically unique. The affinity of 4E17.2A for BoNT/H was increased >500-fold to KD= 1.48 × 10(-10)M (mAb 4E17.2D). A combination of mAbs RAZ1, CR2, and 4E17.2D completely protected mice challenged with 280 mouse median lethal doses of BoNT/H at a mAb dose as low as 5 µg of total antibody. CONCLUSIONS This 3-mAb combination potently neutralized BoNT/H and represents a potential human antitoxin that could be developed for the prevention and treatment of type H botulism.
Collapse
Affiliation(s)
- Yongfeng Fan
- Department of Anesthesia, University of California San Francisco, San Francisco General Hospital
| | - Jason R Barash
- Infant Botulism Treatment and Prevention Program, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, Richmond
| | - Jianlong Lou
- Department of Anesthesia, University of California San Francisco, San Francisco General Hospital
| | - Fraser Conrad
- Department of Anesthesia, University of California San Francisco, San Francisco General Hospital
| | - James D Marks
- Department of Anesthesia, University of California San Francisco, San Francisco General Hospital
| | - Stephen S Arnon
- Infant Botulism Treatment and Prevention Program, Division of Communicable Disease Control, Center for Infectious Diseases, California Department of Public Health, Richmond
| |
Collapse
|
43
|
Spiess C, Zhai Q, Carter PJ. Alternative molecular formats and therapeutic applications for bispecific antibodies. Mol Immunol 2015; 67:95-106. [DOI: 10.1016/j.molimm.2015.01.003] [Citation(s) in RCA: 417] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/30/2014] [Accepted: 01/02/2015] [Indexed: 12/21/2022]
|