Conclusion
The results of this study show that liposome DOTAP+SLA+imiquimod formulation generates a cellular immune response that is protective against challenge against L. major.
Methods
Liposomes were provided applying the lipid film procedure. BALB/C mice were subcutaneously immunized, three times with 2-week intervals, with various formulations. Assessment of lesion development and parasite burden in the foot and spleen after challenge with L. major, assessment of Th1 cytokine (IFN-γ), and titration of IgG isotypes assessed the type of generated immune reaction and the protection extent.
Results
The mice immunized with Liposome DOTAP+imiquimod+SLA showed smaller footpad swelling which was meaningfully different (P<0.05) compared with other groups. The highest level of IgG2a was observed with Lip DOTAP+imiquimod+SLA more than the control (P<0.001). Mice immunized with Lip DOTAP+SLA+imiquimod demonstrated the least number of live parasites in the footpad and spleen. Cytokine assay showed that the greatest IFN- γ secretion was seen in the splenocytes of mice immunized with all formulations as compared to the control group (P<0.0001). In contrast, the lowest IL-4 production was detectable in Lip+imiquimod+SLA spleen, which was not significantly different compared with other groups.