First early wave of response. The very early response to HSV infection of macrophages (Mφ). During the first few hours of infection HSV induces production of IFN-α/β and TNF in macrophages. The implications of these cytokines for HSV replication in neighbouring cells and for macrophage activation and production of reactive oxygen species (ROS) are outlined. Stimulatory pathways are indicated by green arrows (→), and inhibitory pathways are drawn in red.