Gesner T, Mufson R A, Turner K J, Clark S C
Genetics Institute, Cambridge, MA.
Blood. 1989 Dec;74(8):2652-6.
Granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3) each bind specifically to a small number of high-affinity receptors present on the surface of the cells of the acute myelogenous leukemia line, KG-1. Through chemical cross-linking of IL-3 and GM-CSF to KG-1 cells, we identified distinct binding proteins for each of these cytokines with approximate molecular masses of 69 and 93 Kd, respectively. Although these two binding proteins are distinct, GM-CSF and IL-3 compete with each other for binding to KG-1 cells. Other cell lines, which express receptors for either factor but not for both do not display this cross-competition for binding with IL-3 and GM-CSF. These findings imply that distinct IL-3 and GM-CSF binding proteins are expressed on the cell surface and that an association exists between these proteins on KG-1 cells.
粒细胞/巨噬细胞集落刺激因子（GM-CSF）和白细胞介素-3（IL-3）各自特异性结合急性髓性白血病细胞系KG-1细胞表面存在的少量高亲和力受体。通过将IL-3和GM-CSF与KG-1细胞进行化学交联，我们鉴定出这两种细胞因子各自的不同结合蛋白，其近似分子量分别为69和93 kDa。尽管这两种结合蛋白不同，但GM-CSF和IL-3相互竞争与KG-1细胞的结合。其他细胞系，它们表达其中一种因子的受体但不表达另一种因子的受体，不会表现出与IL-3和GM-CSF结合的这种交叉竞争。这些发现表明，不同的IL-3和GM-CSF结合蛋白在细胞表面表达，并且在KG-1细胞上这些蛋白之间存在关联。
