Figure 4.

The “damage chain reaction.” Harmful stimuli, including pathogens, injury, heat, autoantigens, tumor, and necrotic cells, cause tissue damage. Endogenous danger signals are generated and induce a pro-inflammatory cascade by activating TLRs. In turn, pro-inflammatory mediators are upregulated and trigger further tissue damage leading to increasing DAMPs levels. Thus a vicious cycle is sustained and may result in chronic inflammation and autoimmunity.