Figure 3.

Effects of Lutzomyia longipalpis saliva on macrophage activation and neutrophil apoptosis. Macrophages and neutrophils are the first host cells to contact Leishmania after sand fly bite. Saliva triggers macrophages activation by lipid bodies formation committed with the PGE₂ production via COX-2 after phosphorilation of kinases. On the other hand, saliva induces neutrophil apoptosis by caspase and FasL activation. In addition, neutrophils activated by saliva become susceptible to Leishmania chagasi and release MCP-1, which is associated with macrophage recruitment. This scenario promoted by L. longipalpis saliva can contribute to Leishmania transmission in the early times of infection.