Coulie P G, Stevens M, Van Snick J
Unit of Experimental Medicine, Université Catholique de Louvain, Brussels, Belgium.
Eur J Immunol. 1989 Nov;19(11):2107-14. doi: 10.1002/eji.1830191121.
The distribution of the murine receptor for interleukin (IL) 6 was examined on a variety of cells. Binding sites for IL 6 were found on many cell lines including fibroblasts and bone marrow-derived macrophages. The highest density of binding sites was found on B cell hybridomas and plasmacytomas, irrespective of their IL 6 dependence for growth. Scatchard analysis carried out with these cells identified about 1000 high-affinity sites (Kd = 25 pM) and 10,000 low-affinity sites (Kd = 2.5 nM). The binding was specific for IL 6 and led to the internalization of the ligand. Receptors for IL 6 were also present on other B cell lines, but binding on normal resting or activated B cells was below the limit of detection (less than 3 molecules/cell). In contrast, receptors were found on mature thymocytes and on peripheral T cells. However, unlike plasmacytomas and hybridomas, T cells expressed only high-affinity binding sites. The difference in the relative numbers of high- and low-affinity receptors on different cells suggests that IL 6 interacts with several proteins, the expression of which varies from one cell type to another.
在多种细胞上检测了小鼠白细胞介素（IL）-6受体的分布。在包括成纤维细胞和骨髓来源的巨噬细胞在内的许多细胞系上发现了IL-6的结合位点。在B细胞杂交瘤和浆细胞瘤上发现结合位点的密度最高，无论它们对IL-6生长的依赖性如何。对这些细胞进行的Scatchard分析确定了约1000个高亲和力位点（Kd = 25 pM）和10000个低亲和力位点（Kd = 2.5 nM）。这种结合对IL-6具有特异性，并导致配体内化。IL-6受体也存在于其他B细胞系上，但在正常静止或活化的B细胞上的结合低于检测限（小于3个分子/细胞）。相比之下，在成熟胸腺细胞和外周T细胞上发现了受体。然而，与浆细胞瘤和杂交瘤不同，T细胞仅表达高亲和力结合位点。不同细胞上高亲和力和低亲和力受体相对数量的差异表明，IL-6与几种蛋白质相互作用，其表达因细胞类型而异。
