Title:In-Vivo Neutralization of Botulinum Neurotoxin Serotype E Using Rabbit Polyclonal Antibody Developed against BoNT/E Light Chain
Volume: 24
Issue: 6
Author(s): Sarita Rani, S. Ponmariappan*, Arti Sharma, D. V. Kamboj and A. K. Jain
Affiliation:
- Biotechnology Division, Defence Research Development & Establishment, Jhansi Road, Gwalior- 474 002, M.P.,India
Keywords:
Clostridium botulinum, botulinum neurotoxin, botulism, biowarfare agent, neutralizing antibody, therapeutic
intervention.
Abstract: Background: Clostridium botulinum is an obligate anaerobic, Gram positive bacterium
that secretes extremely toxic substances known as botulinum neurotoxins (BoNTs) that cause serious
paralytic illness called botulism. Based upon the serological properties, these neurotoxin have been
classified into seven serotypes designated from A to G. Due to extreme toxicity of BoNTs, these
neurotoxins have been designated as category A biowarfare agents. There is no commercial neutralizing
antibody available for the treatment of botulism. Hence there is an urgent need to develop
therapeutic intervention for prevention and cure of botulism within short period. BoNT antiserum
injection is still the effective treatment.
Method: In the present study, the recombinant light chain of BoNT/E was successfully purified in
soluble form. The purified rBoNT/E LC was used for the generation of polyclonal antibody in rabbit.
In order to find out the neutralizing capacity of generated antisera, rabbit antiserum was incubated
with 20 LD50 of botulinum neurotoxin type E for 1 hour at 37°C and then injected intraperitoneally
(IP) into mice. Further in another set of experiments antiserum was administered in different ways
that included administration of – antiserum and BoNT/E toxin simultaneously without preincubation,
one after another at the same and different time points for its therapeutic ability. To find
out cross neutralization capacity, rBoNT/E LC antiserum was pre-incubated with 5 LD50 of
BoNT/A, BoNT/B, BoNT/F and then injected (IP) into mice. In all the cases mice were observed
continuously for 96 hours.
Result: The results clearly indicate that developed polyclonal rabbit antiserum showed serotype specific
neutralization of BoNT/E toxin only but not of BoNT/A, BoNT/B and BoNT/F.
Conclusion: The developed antibodies will be used for preventive and therapeutic intervention of
type ‘E’ botulism.
