PROTECTIVE VACCINATION WITH A RECOMBINANT FRAGMENT OF CLOSTRIDIUM-BOTULINUM NEUROTOXIN SEROTYPE A EXPRESSED FROM A SYNTHETIC GENE IN ESCHERICHIA-COLI

A completely synthetic gene encoding fragment C, a similar to 50-kDa f ragment, of botulinum neurotoxin serotype A was constructed from oligo nucleotides. The gene was expressed in Escherichia coli, and full-size d product was produced as judged by Western blot (immunoblot) analysis . Crude extracts of E. coli expressing the gene were used to vaccinate mice and evaluate their survival against challenge with active toxin. Mice given three subcutaneous vaccinations were protected against an intraperitoneal administration of 10(6) 50% lethal doses (LD(50)) of s erotype A toxin. The same mice survived when challenged with 3 LD(50) of botulinum toxin serotype E but died when challenged with 10 LD(50) of serotype E or 3 LD(50) of serotype B. Purified fragment C was compa red with the botulinum toroid vaccine in a vaccination and challenge s tudy. Fragment C was as efficacious in protecting against challenge wi th active botulinum neurotoxin serotype A as the toroid vaccine. This recombinant protein product has many properties that make it a good ca ndidate for human use to protect against botulinum toxin.