Assembly of the NLRP3 inflammasome. (a) Without an activator, NLRP3 is autorepressed by the interaction between LRRs and the NACHT domain. (b) NLRP3 activator opens up NLRP3 and allows to interact with ASC. ASC further interacts with procaspase-1. Although a CARDINAL homolog is not present in mice, we showed human CARDINAL, shown with a shade, as a part of the human NLRP3 inflammasome complex. (c) NLRP3 units polymerize. Active caspase-1 processes maturation of IL-1β and IL-18. Pyroptosis is also induced by activated caspase-1.
