IL-18 contributes to susceptibility to Leishmania amazonensis infection by macrophage-independent mechanisms

We evaluated the role of IL-18 during LeishTania amazonensis infection in C57BL/6 mice, using IL-18K0 mice. We showed that IL-18 is involved in susceptibility to L. amazonensis, since IL-18K0 mice presented reduced lesions and parasite loads. Because macrophages are the host cells of the parasite, we investigated if macrophages were involved in IL-18-mediated susceptibility to L. amazonensis. We showed that macrophages obtained from WT or IL-18K0 responded similarly to L. amazonensis infection. Moreover, we showed that C57BL/6 macrophages do not respond to IL-18, since they do not express IL-18R. Therefore, macrophages are not involved in IL-18-mediated susceptibility to L. amazonensis. (C) 2015 Elsevier Ltd. All rights reserved.