The combined use of recombinant and pVAX-omp۳۱ DNA Vaccine for immunological protection against pathogenic Brucellas melitesnsis in an experimental model of BALB/c Mice

Background and Aim: Brucellosis is still an important zoonotic infection and evaluation of immunologic properties of various bacterial antigens along with different vaccination strategies helps in designing efficient vaccines against the disease. The aim of this study is to immunological evaluate the eukaryotic vector pVAX۱, carrying the outer membrane protein gene of ۳۱ kDa (Omp۳۱) B.melitensis. Materials and Methods: In this study which was carried out in ۲۰۱۴, whole sequence of omp۳۱ of B. melitensis was inserted between BamHI and XhoI of pVAX۱ plasmid vector. Female BALB/c mice aged ۶-۸ weeks (purchased from Pasteur Institute of Iran) were immunized intra-muscularly with ۱۰۰μg of the construct, followed by either protein or plasmid boosters separately. The level of IL-۴, IL-۱۲, IFN-γ, total serum IgG, and specific IgG۱ and IgG۲a against recombinant Omp۳۱ were evaluated. Finally the protective immune response following exposure to B. melitensis ۱۶M was evaluated. Results: DNA-vaccine omp۳۱ career with protein reminders Omp۳۱, stimulate higher levels of IFN-γ, IL-۱۲ and IgG۲a compared to groups of DNA-vaccine or recombinant protein. Protective immunity was also significantly higher in mice which immunized with DNA vaccine– protein regimen. Conclusions: Mice which immunized with DNA vaccine–protein regimen showed a significantly higher levels of IL-۱۲ and IFN-γ along with serum IgG۲a which together imply augmentation of T cell-mediated immune responses against Omp۳۱. The latter was confirmed by significant protective response to B. melitensis ۱۶M challenge.

Keywords:

B. melitensis , DNA vaccine , Omp۳۱ , pVAX۱ , بروسلا ملی تنسیس , DNA واکسن , Omp۳۱ , pVAX