IL1B

Interleukin-1 beta (IL-1β) also known as catabolin, is a is_associated_with::cytokine is_associated_with::protein that in humans is encoded by the IL1B is_associated_with::gene. IL-1β precursor is cleaved by cytosolic is_associated_with::caspase 1 (interleukin 1 beta convertase) to form mature IL-1β.

Function
Interleukin 1 was discovered by Igal Gery in 1972. He named it lymphocyte-activating factor (LAF) because it was a lymphocyte mitogen. It was not until 1985 that interleukin 1 was discovered to consist of two distinct proteins, now called is_associated_with::interleukin-1 alpha and interleukin-1 beta.

IL-1β is a member of the is_associated_with::interleukin 1 family of is_associated_with::cytokines. This cytokine is produced by activated macrophages as a proprotein, which is proteolytically processed to its active form by is_associated_with::caspase 1 (CASP1/ICE). This cytokine is an important mediator of the is_associated_with::inflammatory response, and is involved in a variety of cellular activities, including cell proliferation, differentiation, and is_associated_with::apoptosis. The induction of cyclooxygenase-2 (PTGS2/COX2) by this cytokine in the is_associated_with::central nervous system (CNS) is found to contribute to inflammatory is_associated_with::pain hypersensitivity. This gene and eight other interleukin 1 family genes form a cytokine gene cluster on is_associated_with::chromosome 2.

Properties
The molecular weight of the proteolytically processed IL1B is 17.5 kDa. IL1B has the following amino acid sequence: The physiological activity determined from the dose dependent proliferation of murine D10S cells is 2.5 x 108 to 7.1 x 108 units/mg.
 * APVRSLNCTL RDSQQKSLVM SGPYELKALH LQGQDMEQQV VFSMSFVQGE ESNDKIPVAL GLKEKNLYLS CVLKDDKPTL QLESVDPKNY PKKKMEKRFV FNKIEINNKL EFESAQFPNW YISTSQAENM PVFLGGTKGG QDITDFTMQF VSS

Clinical significance
Increased production of IL-1B causes a number of different is_associated_with::autoinflammatory syndromes, most notably the monogenic conditions referred to as CAPS, due to mutations in the inflammasome receptor NLRP3 which triggers processing of IL-1B.

Therapies that target IL1B
is_associated_with::Canakinumab is a human monoclonal antibody targeted at IL-1B, and approved in many countries for treatment of is_associated_with::cryopyrin-associated periodic syndromes.

Orthographic note
Because many authors of scientific manuscripts make the minor error of using a is_associated_with::homoglyph, sharp s (ß), instead of is_associated_with::beta (β), their mentions of "IL-1ß" [sic] often become "IL-1ss" [sic] upon automated is_associated_with::transcoding (because ß transcodes to ss). This is why so many mentions of the latter appear in web search results.