IL-1β is a member of the interleukin 1 family of cytokines. The IL-1 family of cytokines encompasses eleven proteins that each share a similar β-barrel structure and bind to Ig-like receptors. Several of the well characterized members of the IL-1 cytokines play key roles in the development and regulation of inflammation. IL-1α (IL-1F1), IL-1β (IL-1F2), and IL-18 (IL-1F4) are well-known inflammatory cytokines active in the initiation of the inflammatory reaction and in driving Th1 and Th17 inflammatory responses. In contrast, IL-1 receptor antagonist (IL-1ra; IL-1F3) and IL-36 receptor antagonist (IL-36ra; IL-1F5) reduce inflammation by blocking the binding of the agonist receptor ligands. IL-33 (IL-1F11) is thought to function as an ‘alarmin’ released following cell necrosis to alerting the immune system to tissue damage or stress. The biological properties of IL-37 (IL-1F7) are mainly those of down-regulating inflammation.
The IL-1 beta (IL-1β) cytokine is produced by activated macrophages as a proprotein, which is proteolytically processed to its active form by caspase 1 (CASP1/ICE). This cytokine is an important mediator of the inflammatory response and is involved in a variety of cellular activities, including cell proliferation, differentiation, and apoptosis.