An effective Leishmania
vaccine must induce strong Th1 immune responses and generate long-term
effectiveness in the host. To date, most designated anti-Leishmania
vaccines have shown poor efficacy in clinical studies. One of the most
effective approaches in enhancing the efficacy of vaccines to generate
protective immunity is the use of multiple distinct antigens in a single
vaccination regimen. For this reason, we investigated the immunogenicity and protective efficacy of liposomal formulation composed of DOTAP:Cholesterol, protamine and CpG ODNs (LPD NPs) containing rLmaC1N and rgp63 recombinant proteins (LPD-rLmaC1N/rgp63) as an effective vaccine. Then, we have investigated the immunogenicity and protective efficacy of LPD-rLmaC1N/rgp63 in experimental animal model of cutaneous leishmaniasis
compared to free antigens. Our study showed that mice immunization with
LPD-rLmaC1N/rgp63 significantly activates Th1 immune response and
enhances IFN-γ production and IgG2a
levels. Notably, LPD-rLmaC1N/rgp63 immunization greatly reduced the
number of live parasites in the spleen and footpads of immunized mice
compared to other vaccinated groups. As well, the thickness of footpad
was remarkably smaller in mice immunized with LPD-rLmaC1N/rgp63. In
conclusion, our study indicated that LPD-rLmaC1N/rgp63 could be regarded
as a promising multiple-antigen candidate vaccine compared to single
antigen counterparts to generate protective immunity against leishmaniasis. The potential advantages of this formulation may warrant further investigation.