Evaluation of infection course in mice induced by L. major in presence of positively charged liposomes containing CpG ODN

Abstract

An inoculation of virulent <em>Leishmania major</em> is known as leishmanization (LZ) which is proven to be the most effective control measure against Cutaneous Leishmaniasis (CL). However, using LZ is restricted due to various side effects such as uncontrolled lesion development. In the present research, the efficacy of cationic nanoliposomes containing CpG oligodeoxynucleotides (CpG ODN) as an improved adjuvant delivery system was studied to diminish the lesion development and infection course of <em>L. major</em> after inoculation into the mice. BALB/c mice were inoculated subcutaneously (SC) with <em>L. major </em>plus empty DSPC, DSPC (CpG ODN), DSPC (Non CpG ODN), empty DMPC, DMPC (CpG ODN), DMPC (Non CpG ODN) or HEPES buffer. The results showed that group of mice received DMPC (CpG ODN) nanoliposomes developed a significantly smaller lesion and showed minimum number of <em>L. major</em> in the spleen and draining lymph nodes. In addition, using DMPC (CpG ODN) liposomes resulted in a Th1 type of immune response with a preponderance of IgG2a isotype which is concurrent with the production of DMPC (CpG) induced IFN-γ in the spleen of the mice. Taken together, the results suggested that immune modulation using DMPC (CpG ODN) nanoliposomes might be a practical approach to improve the safety of LZ