Characterization of myeloid suppressor cell activity in experimental leishmaniasis

点击翻译按钮获取中文摘要

In experimental leishmaniasis, the clinical course of disease depends on the genetically determined ability of the infected mouse strain to mount a protective T cell-mediated immune response. C57BL/6 mice control parasite replication, whereas BALB/c mice develop a chronic course of disease. Considering these divergent phenotypes, it is most likely that parameters regulating the adaptive immune response against L. major parasites differ in C57BL/6 and BALB/c mice. Recently, myeloid suppressor cells have been described to suppress T cell functions. The most potent suppressive cells are inflammatory CD11b+ monocytes (IMC) that are characterized by the expression of high levels of lymphocyte antigen 6 complex C (Ly-6C), but are negative for Ly-6G. We quantified IMCs at the site of infection and skin-draining lymph nodes (SDLNs) of infected C57BL/6 and BALB/c mice. BALB/c mice showed an increase of IMC at the site of infection and SDLNs, whereas the numbers of IMCs in C57BL/6 SDLNs were not affected. Thus, we propose the hypothesis that IMCs migrate to the site of infection and SDLNs of BALB/c mice to suppress the development of an efficient T cell response. The overall goal of this project is to characterize the different T cell-suppressing mechanisms mediated by IMCs in the experimental model of leishmaniasis.