Interleukin-1 receptor antagonist: discovery, structure and properties

Prog Growth Factor Res. 1990;2(4):193-205. doi: 10.1016/0955-2235(90)90018-f.


Interleukin-1 receptor antagonist (IL-1ra) is a recently-described member of the IL-1 family. This unique human protein has 30% amino acid sequence homology to IL-1 beta and binds to human types I and II IL-1 receptors without apparent cellular activation. IL-1ra blocks the in vitro stimulatory effects of IL-1 on thymocytes, fibroblasts, endothelial cells and bone cells. In addition, IL-1ra is a potent inhibitor of the inflammatory effects of IL-1 in vivo. IL-1ra represents the first naturally-occurring cytokine inhibitor and may be important in modulating IL-1 effects in both normal and abnormal physiology.

Publication types

  • Review

MeSH terms

  • Epithelium / metabolism
  • Humans
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1 / metabolism
  • Molecular Structure
  • Monocytes / metabolism
  • Proteins / chemistry*
  • Proteins / pharmacology
  • Proteins / physiology
  • Sialoglycoproteins*


  • IL1RN protein, human
  • Interleukin 1 Receptor Antagonist Protein
  • Interleukin-1
  • Proteins
  • Sialoglycoproteins