title: Similarity between the interleukin 1 receptors on a murine T-lymphoma cell line and on a murine fibroblast cell line.
abstract: Interleukin 1 beta (IL-1 beta), one of two different polypeptide hormones with interleukin 1 (IL-1) biological activity, produced by activated human monocytes, is a 17.5-kDa protein. IL-1 beta binds specifically to a variety of cells; the cellular distribution of binding is consistent with reported biological responsiveness. In this report we show that two unrelated, but IL-1-responsive, cell lines, LBRM-33-1A5, a T-lymphoma line, and BALB/3T3, a fibroblast line, bind 125I-labeled IL-1 beta via similar plasma membrane receptor molecules. The T-lymphoma cells possess 238 +/- 16 plasma membrane receptors per cell and bind 125I-labeled IL-1 beta with an affinity of 3.6 +/- 0.9 X 10(9) M-1. The IL-1 receptor has a molecular size of approximately equal to 79.5 kDa, as estimated by affinity cross-linking. The fibroblasts possess 4.8 +/- 0.5 X 10(3) IL-1 receptors per cell and bind 125I-labeled IL-1 beta with an affinity of 2.6 +/- 0.5 X 10(9) M-1. The molecular size of the receptor molecule on the fibroblasts is approximately equal to 78 kDa. Despite the similarity in the characteristics of the ligand-receptor system on the two different cell types, the biological responses of the two cell types to IL-1 beta occur at IL-1 beta concentrations that differ by four orders of magnitude.
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D002460:Cell Line; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000032:analysis*; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D008223:Lymphoma / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D011971:Receptors, Immunologic / Q000032:analysis* / Q000302:isolation & purification; D017472:Receptors, Interleukin-1; D013601:T-Lymphocytes / Q000032:analysis*
chemical_list: D007375:Interleukin-1; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1