The role of liposome-protamine-DNA nanoparticles containing CpG oligodeoxynucleotides in the course of infection induced by Leishmania major in BALB/c mice.

An inoculation of virulent Leishmania major is known as leishmanization (LZ) which is proven to be the most effective control measure against cutaneous leishmaniasis (CL) and mimic natural infection. However, use of LZ is restricted due to various reasons such as development of uncontrolled lesion. In the present study, the efficacy of coadminstration of live L. major with liposome-protamine-DNA nanoparticles (LPD) containing immunostimulatory CpG oligodeoxynucleotides (CpG ODN) which is an improved adjuvant delivery system is examined to check Leishmania pathology and immune response generated. BALB/c mice were inoculated subcutaneously (SC) with L. major plus LPD (CpG), CpG ODN or PBS buffer. The results showed that group of mice received LPD nanoparticles developed a significantly smaller lesion and the mice in this group showed minimum number of L. major in the spleen and lymph nodes. In addition, using LPD (CpG) resulted in a Th1 type of immune response with a preponderance of IgG2a isotype which is concurrent with the production of LPD induced IFN-γ in the spleen of the mice. Taken together, the results suggested that immune modulation using LPD nanoparticles might be a practical approach to improve the safety of LZ.