Co-administration of chitin micro-particle and Leishmania antigen proposed a new immune adjuvant against experimental leishmaniasis

Abstract

Aims: We investigated the protective effect of chitin micro-particle (CMP) as an adjuvant against Leishmania infection in BALB/c mice.

Methods: Mice were immunized subcutaneously with soluble Leishmania antigen (SLA) plus CMP (100 µg SLA + 100 µg CMP/100 µL) as the test group. Three weeks after the last immunization, test and control groups were infected by Leishmania major (L major). Eight weeks post-infection, evaluation of parasites load in lymph nodes was performed using limiting dilution assay. Then, the spleen cell cytokine response (TNF-α, IFN-γ, IL-4, IL-10, IL-17 and IL-27) to SLA among vaccinated and nonvaccinated groups was investigated using ELISA. Serum levels of IgG1 and IgG2a were measured as well.

Results: The SLA plus CMP group demonstrated the protection. The responses included reduced lesion formation and lower parasite load. Also, in comparison with control group higher levels of IFN-γ and, IL-10 in the culture of spleen cells, and lower levels of IgG1 in sera were seen in SLA plus CMP group.

Conclusion: The data supported the possibility of using CMP as a suitable adjuvant in Leishmania vaccination.

Keywords: Leishmania major; adjuvant; chitin.