JUN and infection: To assess the role of ROS in the activation of MAPK-dependent AP-1 signaling, Raw 264.7 macrophages were transfected with a luciferase reporter vector containing AP-1 response elements and then infected with T. gondii (multiplicity of infection, MOI = 1) for the time periods indicated (Fig. 2C, top) or with various MOI of T. gondii for 18 h (Fig. 2C, bottom).