Figure 2. Mechanisms of negative regulation mediated by IL-1R2.
In membrane-bound or soluble form IL-1R2 captures IL-1β and IL-1α with high affinity, but not IL-1Ra; it interacts with IL-1RAcp inhibiting the formation of a signalling receptor complex, and with soluble IL-1RAcP, which increases the affinity for IL-1α and IL-1β. In cytosol soluble form, IL-1R2 interacts with pro-IL1α preventing its pro-inflammatory activity during necrosis. In infectious conditions, caspase-1 cleaves IL-1R2 and allows the secretion of IL-1α.