Tsukamoto H, Nagasawa K, Ueda Y, Mayumi T, Furugo I, Tsuru T, Niho Y
First Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Immunology. 1992 Dec;77(4):621-3.
Association of complement synthesis with cell differentiation in U937 cells was investigated using granulocyte-macrophage colony-stimulating factor (GM-CSF), vitamin D3 and interferon-gamma (IFN-gamma) as differentiation-inducing agents. GM-CSF or vitamin D3 enhanced the synthesis of the third component of complement (C3) by U937 cells, but had no stimulatory effect on the synthesis of the fourth component of complement (C4). IFN-gamma increased both C3 and C4 synthesis by U937 cells. Combination of two of these three agents resulted in synergistic enhancement and all three agents caused maximal enhancement of C3 synthesis. Vitamin D3 enhanced IFN-gamma-induced C4 synthesis by U937 cells. These results were confirmed by ELISA and SDS-PAGE after biosynthetic labelling. GM-CSF, vitamin D3 or IFN-gamma increased the expression of complement receptor type 3 (CR3), one of the markers of monocyte/macrophage differentiation. Two of these agents caused a further increase and all three agents maximal increase in CR3 expression. Since C3 was synthesized in parallel with the degree of CR3 expression, the synthesis of C3, but not C4, by U937 cells is thought to be closely related to cell differentiation. It was reconfirmed that the synthesis of C3 and C4 by U937 cells was independently regulated.
使用粒细胞-巨噬细胞集落刺激因子（GM-CSF）、维生素D3和γ干扰素（IFN-γ）作为分化诱导剂，研究了U937细胞中补体合成与细胞分化的关系。GM-CSF或维生素D3可增强U937细胞补体第三成分（C3）的合成，但对补体第四成分（C4）的合成无刺激作用。IFN-γ可增加U937细胞中C3和C4的合成。这三种试剂中的两种联合使用可导致协同增强，而三种试剂共同作用则使C3合成得到最大增强。维生素D3可增强IFN-γ诱导的U937细胞C4合成。生物合成标记后的ELISA和SDS-PAGE证实了这些结果。GM-CSF、维生素D3或IFN-γ可增加补体3型受体（CR3）的表达，CR3是单核细胞/巨噬细胞分化的标志物之一。其中两种试剂可使CR3表达进一步增加，而三种试剂共同作用则使CR3表达达到最大增加。由于C3的合成与CR3表达程度平行，因此认为U937细胞中C3而非C4的合成与细胞分化密切相关。再次证实U937细胞中C3和C4的合成是独立调节的。
