Cellular & Molecular Medicine: Open access

Abstract

Leishmaniasis is one of the main vector-borne diseases caused by an intracellular protozoan parasite of the genus Leishmania. Cutaneous Leishmaniasis (CL) is the most common form of the disease. In the absence of an effective vaccine and a well-proven therapeutic approach to cure the disease, a deeper understanding of the immunity against leishmaniasis, especially the study of the impact of cytokines on the course and outcome of infection, is the key to optimize the management of the disease. To address this, an experimental model of CL was developed to assess the role of IL-13 in shaping the course of infection in BALB/c mice infected with low and high dose of L. major. This model offered a perfect venue to assess the effect of IL-13 on the parasite burden and on the paw thickness. Furthermore, it was possible to investigate the cytokine mode of action by monitoring its impact on the levels of key Th1 and Th2 cytokines. Our findings suggest that susceptible BALB/c mice infected with high and low dose of L. major exhibit high parasite burden and paw swelling in the presence of IL-13, which leads to a Th2 inflammatory response causing a non-healing track of the disease. Our work also highlights the ability of hypoalgesic exogenous IL-13 to induce susceptibility to L. major infection.