Differential regulation of dendritic cells migration after L. major and L. amazonensis infection

Leishmaniasis is an endemic disease in tropical and subtropical regions of the world, where it is mainly manifested within mammals. This zoonotic disease is caused by an infection with a protozoan parasite called Leishmania, which resides within the mammal\u27s macrophages and/or dendritic cells.;In this study we worked with 2 different species of Leishmania responsible for the cutaneous form of the disease, Leishmania major and Leishmania amazonensis. Generally, when C3H mice are infected with L. major, the mice display cutaneous self-healing lesions. The resolution of these lesions is characterized by a strong Th1 response. However, when C3H mice are infected with L. amazonensis, lesions do not heal due to an inability of the mice to mount an effective Th1 response.;This study was aimed to determine the effects of L. major and L. amazonensis on dendritic cells migration in vitro. Bone marrow derived-dendritic cells were infected with both the promastigotes and the amastigotes forms of L. major and L. amazonensis to detect differences between species or morphological forms. These studies indicate that bone marrow derived-dendritic cells infected with L. amazonensis amastigote after 24 hour display an impaired migration towards MIP-3beta and produce much lower levels of IL-12p40, an important Th1 cytokine, than cells infected with L. major amastigotes. These two major events may very well play an important role on susceptibility to L. amazonensis infection