IL-1H, an interleukin 1-related protein that binds IL-18 receptor/IL-1Rrp

Cytokine. 2001 Jan 7;13(1):1-7. doi: 10.1006/cyto.2000.0799.


IL-18, or IGIF (interferon-gamma inducing factor), is an IL-1-related, pro-inflammatory cytokine, which plays a pivotal role in systemic and local inflammation. We have identified and characterized IL-1H, a novel IL-1-related molecule. IL-1H appears to be expressed in most tissues with relatively high levels in testis, thymus and uterus. The IL-1H transcripts were stimulated by phorbol ester (PMA) in human cell lines (A431, THP-1 and KG-1) and peripheral blood mononuclear cells (HPBMC) and dendritic cells (NHDC). The protein sequence of IL-1H is mostly related to IL-1ra with a similarity of 36%. A short form of IL-1H was identified, and lacks a 40-amino acid segment in the amino-terminal region of the protein. When expressed in mammalian cells, two secreted polypeptides of IL-1H were identified: an uncleaved and a cleaved form starting with amino acid Val-46. Furthermore, IL-1H binds the IL-18 receptor, but not the IL-1 receptor. These findings suggest that IL-1H may be another ligand for the IL-18 receptor and a new player in the inflammatory and immune responses mediated by the IL-18/IL-18R axis.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • CHO Cells
  • Cell Line
  • Cloning, Molecular
  • Cricetinae
  • DNA Primers / genetics
  • Female
  • Gene Expression Regulation / drug effects
  • Humans
  • In Vitro Techniques
  • Interleukin-18 Receptor alpha Subunit
  • Male
  • Models, Molecular
  • Molecular Sequence Data
  • Protein Binding
  • Protein Conformation
  • Proteins / metabolism*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Interleukin / chemistry
  • Receptors, Interleukin / genetics*
  • Receptors, Interleukin / metabolism*
  • Receptors, Interleukin-18
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Tetradecanoylphorbol Acetate / pharmacology
  • Tissue Distribution
  • Transfection


  • DNA Primers
  • IL-1H receptor
  • IL18R1 protein, human
  • Interleukin-18 Receptor alpha Subunit
  • Proteins
  • RNA, Messenger
  • Receptors, Interleukin
  • Receptors, Interleukin-18
  • Recombinant Proteins
  • Tetradecanoylphorbol Acetate

Associated data

  • GENBANK/AF251118
  • GENBANK/AF251119
  • GENBANK/AF251120