Study of adjuvant capability of the gold nanoparticles on immunity of botulinum neurotoxin serotype E in mouse

Botulism is a dangerous neuroparalytic syndrome caused by Clostridiumbotulinum neurotoxins (serotypes A-G). The more studieshaveshown that the binding domains in all neurotoxin types (A-G) have a great importance in immunity against the botulism syndrome and nowadays، this domain has been introduced as a vaccine candidate. In this study، for evaluation of adjuvant effect of Gold Nanoparticles (GNPs) on a vaccine candidate، the botulinum neurotoxin type E binding domain was used. In vaccine studies one of the problems is thepresence of a potent and biocompatible adjuvant withfewer side effects. For developing of new adjuvantswecompared the adjuvant properties of GNPs to Freund’s adjuvant (FA). A recombinant binding domain BoNT/E conjugated with GNPs was prepared and injected four times into 45 mice in two groups، that one group alone and another one with FA. Then the antibody titers were compared with Antigen-FA group and ultimately the mice were challenged by active BoNT/E. The results showed that the immunized mice with GNP-Ag and GNP-Ag-FA produced high titers of antibody and immune response comparable with FA-Ag group. As regards to antibodyinduction، challenge resultsand itsbiocompatibility، we can introduce the GNPs as a better adjuvant in compare with FA.