Human botulism can result from the ingestion of food contaminated with botulinum neurotoxin (BoNT), from the infection of wounds or intestine, or from direct inhalation of the toxin, which can be transcytosed across epithelial barriers as a physiologically active molecule. Intoxication, if untreated, may lead to death due to respiratory muscle failure, while recovery from botulism is a prolonged process (up to several months) and may require intensive and expensive hospital care. Due to their extreme toxicity and ease of production, BoNTs are classified as one of the six highest-risk threat agents for bioterrorism by the US Center for Disease Control and Prevention (CDC). Developing antidotes to botulinum neurotoxins is a priority goal of the Biodefense Research Agenda. Our laboratory has developed genetic constructs and expression systems based on recombinant, full- length, atoxic BoNT derivatives that preserve key structural features of the wt BoNT/A required for physiological trafficking, and enable the development of novel anti-BoNT therapeutics (ABTs) that will be effective in a post-exposure setting by oral or inhalational routes. The construction and expression of these atoxic BoNT derivatives provide molecular delivery vehicles that target motor neurons, and can contain specific sites for enzymatic attachment of a wide variety of cargo and tracker molecules. The genetic constructs are modular by design, and enable the facile production of diverse candidate ABTs for evaluation. In this application we will test two approaches for delivering therapeutic moieties to target neurons: a) For the ABT-1 approach, therapeutic moieties effective against all BoNT serotypes will be incorporated directly into the amino acid sequence of the BoNT atoxic light chain (LC) metalloprotease, which will be expressed in combination with the BoNT/A heavy chain (HC) as full-length ABT-1;b) For the ABT-2 approach, a therapeutic moiety specifically active against wt BoNT/A will be coupled to the full length ABT-2 by site- selective enzymatic attachment to the ABT-2 precursor, carried by the BoNT/A heavy chain. The full-length BoNT derivatives we propose are expected to have unique advantages with respect to their ability to compete with wild type toxin for neuronal binding sites, and to mimic the endosome-to-cytosol channeling required for delivery of ABTs to the neuronal cytosol. Our current methods can produce sufficient quantities for in vitro and in vivo testing. These ABTs can be administered in a post-exposure setting by oral or inhalational routes.

Public Health Relevance

The goal of this project is to create anti-botulinum neurotoxin therapeutics and to test these therapeutics for efficacy and toxicity in model assays and in preclinical in vivo systems. This project provides product-ready alternatives to currently existing treatment modalities, including passive immunotherapy and vaccination, which have well described limitations. It is recognized that a large botulism outbreak would be disastrous due to lack of sufficient numbers of ICUs equipped with mechanical ventilators for prolonged life support, and the lack of an antidote that is effective after the toxin has entered neuronal cells (24-48 hours after intoxication), which emphasizes the need for a therapeutics that can treat botulism by inactivating BoNT after neuronal entry.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI093504-01
Application #
8077790
Study Section
Special Emphasis Panel (ZAI1-LG-M (J1))
Program Officer
Ranallo, Ryan
Project Start
2011-04-15
Project End
2016-05-31
Budget Start
2011-04-15
Budget End
2012-03-31
Support Year
1
Fiscal Year
2011
Total Cost
$1,381,473
Indirect Cost
Name
New York University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
121911077
City
New York
State
NY
Country
United States
Zip Code
10016
Beske, Phillip H; Hoffman, Katie M; Machamer, James B et al. (2017) Use-dependent potentiation of voltage-gated calcium channels rescues neurotransmission in nerve terminals intoxicated by botulinum neurotoxin serotype A. Sci Rep 7:15862
Pellett, Sabine; Tepp, William H; Johnson, Eric A et al. (2017) Assessment of ELISA as endpoint in neuronal cell-based assay for BoNT detection using hiPSC derived neurons. J Pharmacol Toxicol Methods 88:1-6
Vazquez-Cintron, Edwin J; Beske, Phillip H; Tenezaca, Luis et al. (2017) Engineering Botulinum Neurotoxin C1 as a Molecular Vehicle for Intra-Neuronal Drug Delivery. Sci Rep 7:42923
Beske, Phillip H; Bradford, Aaron B; Grynovicki, Justin O et al. (2016) Botulinum and Tetanus Neurotoxin-Induced Blockade of Synaptic Transmission in Networked Cultures of Human and Rodent Neurons. Toxicol Sci 149:503-15
Vazquez-Cintron, Edwin; Tenezaca, Luis; Angeles, Christopher et al. (2016) Pre-Clinical Study of a Novel Recombinant Botulinum Neurotoxin Derivative Engineered for Improved Safety. Sci Rep 6:30429
Pellett, Sabine; Tepp, William H; Scherf, Jacob M et al. (2015) Botulinum Neurotoxins Can Enter Cultured Neurons Independent of Synaptic Vesicle Recycling. PLoS One 10:e0133737
Lin, Guangyun; Tepp, William H; Bradshaw, Marite et al. (2015) Immunoprecipitation of native botulinum neurotoxin complexes from Clostridium botulinum subtype A strains. Appl Environ Microbiol 81:481-91
Pellett, Sabine; Schwartz, Michael P; Tepp, William H et al. (2015) Human Induced Pluripotent Stem Cell Derived Neuronal Cells Cultured on Chemically-Defined Hydrogels for Sensitive In Vitro Detection of Botulinum Neurotoxin. Sci Rep 5:14566
Pellett, Sabine; Tepp, William H; Scherf, Jacob M et al. (2015) Activity of botulinum neurotoxin type D (strain 1873) in human neurons. Toxicon 101:63-9
Scherf, Jacob M; Hu, Xiaoyang Serene; Tepp, William H et al. (2014) Analysis of gene expression in induced pluripotent stem cell-derived human neurons exposed to botulinum neurotoxin A subtype 1 and a type A atoxic derivative. PLoS One 9:e111238

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