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

ABSTRACT

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]. 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 L. major after inoculation into the mice. BALB/c mice were inoculated subcutaneously [SC] with L. major 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 L. major 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-gamma 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