Human Interleukin-1

The Interleukin-1 family (IL-1 family) is a group of 11 cytokines, which plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults. IL-1 family is a group of 11 cytokines, which induces a complex network of proinflammatory cytokines and via expression of integrins on leukocytes and endothelial cells, regulates and initiates inflammatory responses. IL-1α and IL-1β are the most studied members, because they were discovered first and because they possess strongly proinflammatory effect. They have a natural antagonist IL-1Ra (IL-1 receptor antagonist). All three of them include a beta trefoil fold and bind IL-1 receptor (IL-1R) and activate signaling via MyD88 adaptor, which is described in the Signaling section of this page. IL-1Ra regulates IL-1α and IL-1β proinflammatory activity by competing with them for binding sites of the receptor.