An antibody to a 17 amino acid synthetic peptide of the type I interleukin-1 receptor preferentially blocks interleukin-1 beta binding

J Interferon Cytokine Res. 1996 Dec;16(12):1079-88. doi: 10.1089/jir.1996.16.1079.


On the basis of their relative hydropathy and alpha-helical structure, we prepared antibodies to four synthetic peptides with amino acid sequences homolgous to four hydrophilic, extracellular regions of the murine 80 kDa type I interleukin-1 receptor (IL-1RI). Antibodies to each of the four peptides recognized their specific immunogen. Human [125I]-IL-1 alpha or -beta was crosslinked to murine EL4 and D10S cells. Antiserum to peptide 150-166 precipitated the IL-1/IL-1R complex, whereas antibodies to peptide 66-84, 190-200, or 266-285 did not. Antibody to peptide 150-166 did not precipitate the type II IL-1R. Anti-IL-1RI150-166 blocked 71% of the binding of radiolabeled human IL-1 beta to EL4 cells and 50% of the binding to D10S cells. Using affinity-purified anti-IL-1RI150-166, we compared the ability of this antibody to inhibit the binding of murine or human IL-1 alpha to that of murine or human IL-1 beta. At a concentration of 20 ng/ml, affinity-purified anti-IL-1RI150-166 blocked 50% binding of murine IL-1 beta. At 1 microgram/ml, 90% blockage was observed. In contrast, no significant blockade of IL-1 alpha binding was observed at concentrations as high as 3 micrograms/ml of anti-IL-1RI150-166. The selective blockade of IL-1 beta forms was not due to differences in the affinities of these ligands for receptors on these cells. The antibody also blocked the binding of human IL-1 beta but not human IL-1 alpha to EL4 cells. The biologic activity of murine IL-1 beta but not IL-1 alpha on EL4 cells was also inhibited by this antibody. These data suggest (1) that antibody to a specific epitope on the extracellular domain interferes with the binding of IL-1 beta but not IL-1 alpha, (2) the differential inhibition of binding of IL-1 beta but not IL-1 alpha by anti-IL-1RI150-166 also blocks biologic activity, and (3) IL-1 alpha and IL-1 beta may transduce different signals by binding to separate loci on the IL-1RI.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen-Antibody Reactions*
  • Binding Sites
  • Cell Line
  • Humans
  • Immunoglobulins / chemistry
  • Interleukin-1 / metabolism*
  • Mice
  • Molecular Sequence Data
  • Molecular Weight
  • Peptide Fragments / immunology*
  • Precipitin Tests
  • Protein Structure, Secondary*
  • Receptors, Interleukin-1 / chemistry
  • Receptors, Interleukin-1 / immunology*
  • Receptors, Interleukin-1 / metabolism
  • Solubility
  • Tumor Cells, Cultured
  • Water / chemistry


  • Immunoglobulins
  • Interleukin-1
  • Peptide Fragments
  • Receptors, Interleukin-1
  • Water