Recombinant human Flt3 ligand exerts both direct and indirect effects on hematopoiesis  

重组人Flt3配体在造血过程中存在直接和间接作用(英文)

作　　者：许志祥[1] 徐颖[1] 朱剑昆[1] 施勤[1] 李颖[1] 张学光[1] 

机构地区：[1]苏州医学院医学生物技术研究所免疫研究室,苏州215007

出　　处：《Chinese Medical Journal》2002年第2期202-205,149,共4页中华医学杂志（英文版）

基　　金：agrantfromtheIAEAFoundationfortheProtectionofAcuteIrradiationInjury (No CPR/9/0 2 5 )

摘　　要：OBJECTIVE: To investigate the direct effects of the Flt3 ligand (FL) on hematopoiesis, such as the stimulation of the formation of hematopoietic colonies and the proliferation of dendritic cells, as well as the indirect stimulation of hematopoiesis, especially via the proliferation of endothelial cells. METHODS: Mononuclear cells from human cord blood were plated in methylcellulose medium containing different cytokines to induce hematopoietic colony formation. Dendritic cells (DCs) were induced from the mononuclear cells with a cytokine cocktail with or without recombinant human soluble FL (rhFL; 100 ng/ml). The Flt3 receptors on the surface of a human microvascular endothelial cell line (ECV) were analyzed by flow cytometry. The proliferation of ECV stimulated by rhFL was measured with the microculture tetrazolium assay. The levels of FL, IL-6, IL-8, G-CSF and GM-CSF in the supernatant of ECV cultures were measured by enzyme linked immunoabsorbent assay (ELISA). RESULTS: rhFL stimulates colony formation from cord blood when used as a sole stimulant. FL in combination with other cytokines increased colony formation significantly. The number of DCs was approximately 2.5 times higher when rhFL was used. rhFL stimulates the proliferation of ECV on which Flt3 receptors are expressed. Furthermore, ECV secretes FL, IL-6, IL-8, G-CSF and GM-CSF, which were augmented by tumor necrosis factor-alpha and rhFL. CONCLUSIONS: rhFL enhances hematopoietic colony formation and DC proliferation from human cord blood cells. FL not only stimulates the proliferation of ECV, but is also secreted by ECV. FL may exert direct and indirect effects on hematopoiesis.目的　研究重组人Flt3配体 (rhFL)对造血的直接作用 ,如造血集落形成、树突状细胞的增殖等 ,并研究rhFL刺激内皮细胞 (ECV)增殖 ,对造血的间接作用。方法　采用甲基纤维素半固体集落形成试验 ,观察rhFL单独或与其它细胞因子联合对脐血造血细胞体外集落形成的影响 ,计数自脐血细胞产生的造血集落数 ;用含有 10 0ng/mlrhFL等多种细胞因子混合的方法 ,自人脐血单个核细胞中诱导产生树突状细胞 (DC)。用流式细胞仪测定人ECV表面Flt3受体的表达 ,用MTT法分析rhFL对ECV的促增殖作用。同时还测定了ECV培养上清中FL、IL 6、IL 8、G CSF和GM CSF的水平。结果　rhFL可显著促进人脐带血造血细胞体外集落的形成 ,与其它细胞因子合用时 ,作用明显增强 ;当rhFL与其它诱导DC的细胞因子联合使用时 ,诱导的树突状细胞数增加 2 5倍。ECV表达Flt3受体 ,rhFL促进ECV的增殖。另外 ,ECV能够分泌FL、IL 6、IL 8、G CSF和GM CSF ,TNFα和rhFL促进ECV分泌FL。结论　rhFL增强自脐血单个核细胞诱导产生造血集落和DC。FL不仅能够刺激ECV的增殖 ,而且ECV可分泌FL。FL在机体的造血过程中可能起直接和简接作用。

关 键 词：Cell Division Cell Line Dendritic Cells DEXAMETHASONE Dose-Response Relationship  Drug Endothelium  Vascular Fetal Blood HEMATOPOIESIS Hematopoietic Stem Cells Humans IMMUNOPHENOTYPING Membrane Proteins Recombinant Proteins Research Support  Non-U.S. Gov't Tumor Necrosis Factor-alpha 

分 类 号：R331.1[医药卫生—人体生理学]