The interleukin-1 receptor antagonist protein (IL-1RN) is a protein that in humans is encoded by the IL1RN gene.
IL-1RN is an agent that binds non-productively to the cell surface interleukin-1 receptor (IL-1R), the same receptor that binds interleukin 1 family (IL-1), preventing IL-1’s from sending a signal to that cell.
IL-1RA is a member of the interleukin 1 cytokine family, and is secreted by various cells including: immune cells, epithelial cells, and adipocytes.
It is a natural inhibitor of the pro-inflammatory effect of IL1β.
This protein inhibits the activities of interleukin 1, alpha (IL1A) and interleukin 1, beta (IL1B), and modulates a variety of interleukin 1 related immune and inflammatory responses.
This gene and five other closely related cytokine genes form a gene cluster spanning approximately 400 kb on chromosome 2.
A polymorphism of this gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer.
Mutations in the IL1RN gene results in a rare disease called deficiency of the interleukin-1–receptor antagonist (DIRA).
Variants of the IL1RN gene is also associated with risk of schizophrenia, and elevated levels of IL1RN has been found in serum of schizophrenia patients.
A recombinant, slightly modified version of interleukin 1 receptor antagonist called anakinra is used in the treatment of rheumatoid arthritis, an autoimmune disease in which IL-1 plays a key role.
Anakinra differs from native human IL-1Ra in that it has the addition of a single methionine residue at its amino terminus.