Medical College of Wisconsin
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Nontoxic, multi-domain botulinum neurotoxin-LCHCN as vaccines against botulism. Vaccine 2025 Oct 24;65:127779

Date

09/25/2025

Pubmed ID

40997375

Pubmed Central ID

PMC13246459

DOI

10.1016/j.vaccine.2025.127779

Scopus ID

2-s2.0-105019270072 (requires institutional sign-in at Scopus site)   1 Citation

Abstract

Botulinum neurotoxins (BoNTs), the causative agents of botulism, are proteins consisting of an N-terminal catalytic Light Chain (LC) and a C-terminal Heavy Chain (HC), which comprises a LC-translocation domain (HCN) and a receptor binding domain (HCC). There are seven BoNT serotypes (A-G) and multiple subtypes. Currently, there is no approved vaccine against botulism available for human use. Several studies have investigated BoNT domains, multi-domains, or mutated holotoxins as candidate BoNT vaccines. However, residual toxicity has been observed in mutated full-length BoNTs and multi-domain (LCHCN) vaccines. In this study, six-individual point substitutions (6M) were introduced into the substrate binding and cleavage sites, zinc binding motif, and LC translocation region of LCHCN/A1 and LCHCN/B1, which possessed no detectable toxicity in mice at 200 μg, being >40-million-fold less toxic than full-length BoNT. IP immunization of mice with 6MLCHCN/A1 or 6MLCHCN/B1 elicited a strong IgG response that protected against high dose challenge with BoNT/A1 or BoNT/B1, respectively. 4MBoNT/B1 and 7MBoNT/B1 were also engineered and found to elicit strong IgG responses that protected against high dose challenge with BoNT/B1. Thus, multi-domain inactivation may yield potent and safe vaccines against other BoNT-serotypes and BoNT-like proteins. The strategy of systematic inactivation of multiple functional domains by targeted single amino acid substitutions to decrease toxicity, combined with investigations of the most immunogenic and protective domains, provides a robust platform for protein toxin vaccines for humans and animals.

Author List

Przedpelski A, Tepp WH, Gupta S, Barbieri JT, Pellett S

Author

Joseph T. Barbieri PhD Professor in the Microbiology and Immunology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Animals
Antibodies, Bacterial
Antibodies, Neutralizing
Bacterial Vaccines
Botulinum Toxins
Botulism
Female
Immunoglobulin G
Mice
Mice, Inbred BALB C