The Route of Leishmania tropica Infection Determines Disease Outcome and Protection against Leishmania major in BALB/c Mice

Leishmania tropica is one of the causative agents of leishmaniasis in humans. Routes of infection have been reported to be an important variable for some species of Leishmania parasites. The role of this variable is not clear for L. tropica infection. The aim of this study was to explore the effects of route of L. tropica infection on the disease outcome and immunologic parameters in BALB/c mice. Two routes were used; subcutaneous in the footpad and intradermal in the ear. Mice were challenged by Leishmani major, after establishment of the L. tropica infection, to evaluate the level of protective immunity. Immune responses were assayed at week 1 and week 4 after challenge. The subcutaneous route in the footpad in comparison to the intradermal route in the ear induced significantly more protective immunity against L. major challenge, including higher delayed-type hypersensitivity responses, more rapid lesion resolution, lower parasite loads, and lower levels of IL-10. Our data showed that the route of infection in BALB/c model of L. tropica infection is an important variable and should be considered in developing an appropriate experimental model for L. tropica infections.

Immunotherapy with imiquimod increases the efficacy of glucantime therapy of leishmania major infection

Leishmaniasis is a complex disease which presents as visceral, cutaneous and mucocutaneous forms. The current treatment options for this infection are very limited and the immunological state of the host appears to play an important role in the efficacy of the treatment. Immunostimulation through immune response activating agents such as Imiquimod is another rational approach for this purpose. We assessed the efficacy of immunotherapy with Imiquimod alone or combined with Glucantime for treatment of Leishmania major infection in BALB/c mice. Treatment efficacy was monitored by determination of thickness and parasite load of infected foot-pad of mice. The footpad thickness revealed that treatment with Imiquimod plus Glucantime has the highest efficacy. The results were confirmed by parasite load of infected footpad. Our data shows that treatment of Leishmania major infection in BALB/c mice by the combined Imiquimod and Glucantime is more efficient than each drug alone. The combination of Imiquimod with chemotherapy may offer a way for more efficient treatment of leishmaniasis