DNA vaccination using the fragment C of botulinum neurotoxin type A provided protective immunity in mice

Botulinum neurotoxin (BoNT) is one of the most toxic substances known to pr oduce severe neuromuscular paralysis. The currently used vaccine is prepare d mainly from biohazardous toxins. Thus, we studied an alternative method a nd demonstrated that DNA immunization provided sufficient protection agains t botulism in a murine model. A plasmid of pBoNT/A-Hc, which encodes the fr agment C gene of type A botulinum neurotoxin, was constructed and fused wit h an Ig kappa leader sequence under the control of a human cytomegalovirus promoter. After 10 cycles of DNA inoculation with this plasmid, mice surviv ed lethal doses of type A botulinum neurotoxin challenges. Immunized mice a lso elicited cross-protection to the challenges of type E botulinum neuroto xin. This is the first study demonstrating the potential use of DNA vaccina tion for botulinum neurotoxins. (C) 2000 National Science Council, ROC and S. Karger AG, Basel.