Fig. 1.

The NLRP3 inflammasome is a cytosolic protein complex consisting of NLRP3, ASC (apoptosis-associated speck-like protein) and pro-caspase-1. The inflammasome assembly can be triggered by various pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). Upon activation, pro-caspase-1 is turned into its active form, caspase-1. Caspase-1 cleaves pro-interleukin (IL)-1β and pro-IL-18 into their mature forms, with ensuing secretion from the cell. IL-1β binds to its receptor complex consisting of IL-1R1 and IL-R1AcP and initiates a signal cascade leading to proinflammatory effects. IL-Ra is an IL-1 receptor antagonist and regulates the activity of IL-1β by competing with binding to the receptor.