Induction of immune responses by protein vaccines formulated with adjuvants against Leishmania major in vivo

Abstract

We used TSA as a principal antigen of Leishmania major with adjuvants. The aim of this research was to assess the efficacy of protein vaccine in the presence of Montanide vis-a-vis chitosan nanoparticle. The expression of recombinant protein was confirmed with SDS (sodium dodecyl sulfate) page and Western blotting. A total of 36 BALB/c mice were divided into six groups (TSA/high chitosan, TSA/low chitosan, TSA/Montanide, high chitosan, low chitosan, and PBS groups) and subcutaneously immunized with 20 mg of vaccine at three time intervals on days 0, 14, and 28. The mice were challenged with parasites 21 days after the final immunization. For assaying lymphocyte proliferation, the Brdu test and for evaluation of IgG subclasses and cytokines, the ELISA method was carried out. No statistically noteworthy variation was found between the vaccinated groups before and after the infectious challenge or intervention in terms of IgG and IFN-γ values. Statistically, significant difference was seen among the vaccinated and control groups in terms of IgG and IFN-γ. In terms of IL-4 before and after intervention, no statistically substantial difference was noted in the vaccinated and control groups, whereas, IgG isotypes rose to a great extent prior to and following intervention in all vaccine-immunized groups as compared with control groups. The formulated recombinant TSA protein vaccine with adjuvants induced lymphocytes proliferation and increased cytokines and antibodies as compared with the control groups. Given their potency, the formulated candidate vaccines may be recommended for further studies.