Characterization and identification of interleukin-1 receptors on bovine fibroblasts.
Interleukin-1 (IL-1), a pro-inflammatory cytokine, initiates its many biological effects by first binding to cell-surface receptors. Prior to this study, there were no published reports addressing the nature of the bovine IL-1 receptor. In this study, we characterized and identified cell-surface IL-1 receptors on bovine fibroblasts. Direct binding studies using [125I]-labeled bovine IL-1 beta demonstrated that bovine fibroblasts had approximately 130 high affinity and 2,500 low affinity binding sites (Kd = 4.9 x 10(-11) M and 3.7 x 10(-9) M, respectively). Competitive binding studies using unlabeled recombinant bovine IL-1 beta, IL-2, IFN-alpha, and bovine insulin demonstrated that only unlabeled bovine IL-1 beta competitively blocked fibroblast binding of [125I]-labeled bovine IL-1 beta. Affinity cross-linking of [125I]-labeled IL-1 beta to fibroblasts demonstrated that IL-1 receptors on bovine fibroblasts have an apparent M(r) of 71.5 kD. This report provides the first characterization and identification of IL-1 receptors on bovine fibroblasts.
Lederer
J
J
Department of Pathobiological Sciences, University of Wisconsin-Madison School of Veterinary Medicine 53706.
Czuprynski
C
C
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002417:Cattle; D002478:Cells, Cultured / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism; D017472:Receptors, Interleukin-1 / Q000737:chemistry* / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D007375:Interleukin-1; D017472:Receptors, Interleukin-1; D011994:Recombinant Proteins