Cytokines and dendritic cell activation. DCs both produce cytokines and are susceptible to cytokine-mediated activation. Thus, exposure to DC activators, for example TLR ligands or microbes, triggers secretion of pro-inflammatory cytokines including type I interferons (IFN), acute phase cytokines such as TNF and IL-6, IL-1 as well as IL-12 family (left panel). Several cytokines are able to trigger DCs activation (maturation) either in autocrine or paracrine fashion including IL-1, TNF, type I IFNs and TSLP (right panel).