Conget P, Minguell J J
Unidad de Biología Celular, INTA, Universidad de Chile, Santiago.
Br J Haematol. 1995 Jan;89(1):1-7. doi: 10.1111/j.1365-2141.1995.tb08918.x.
Haemopoietic progenitor cells (HPC) synthesize and accumulate a single type of membrane-associated chondroitin sulphate proteoglycan (MA-PG), which participates in HPC adhesiveness to fibronectin by interacting with its heparin-binding domain. Shortly after incubating cells with IL-3, we observed an increase in MA-PG synthesis in the multipotent (FDCP-mix) but not in the bipotent (FDCP-1) progenitor cell line. The charge density, hydrodynamic size, nature of the glycosaminoglycan (GAG) chains and stability of MA-PG from IL-3-treated and non-treated FDCP-mix cells were the same, suggesting that IL-3 affects the amount of MA-PG. The latter was evaluated by flow cytometry using monoclonal antibodies to the core protein and GAG residues. In all cases the mean fluorescence intensities were higher for IL-3-treated than for untreated cells. Cell adhesion studies to dishes coated with the fibronectin 40 kD fragment, containing the heparin-binding domain, demonstrated that adhesiveness of IL-3-treated cells was higher than that of untreated cells. These results suggest that in multipotent haemopoietic cells IL-3 regulates the amount of membrane-associated proteoglycans, which in turn modify the adhesive interactions of cells with the heparin-binding domain of fibronectin.
造血祖细胞（HPC）合成并积累单一类型的膜相关硫酸软骨素蛋白聚糖（MA-PG），该蛋白聚糖通过与其肝素结合域相互作用参与HPC与纤连蛋白的黏附。在用白细胞介素-3（IL-3）孵育细胞后不久，我们观察到多能（FDCP-mix）祖细胞系中MA-PG的合成增加，而双能（FDCP-1）祖细胞系中则没有增加。来自经IL-3处理和未处理的FDCP-mix细胞的MA-PG的电荷密度、流体力学大小、糖胺聚糖（GAG）链的性质和稳定性相同，这表明IL-3影响MA-PG的量。通过使用针对核心蛋白和GAG残基的单克隆抗体的流式细胞术评估了后者。在所有情况下，经IL-3处理的细胞的平均荧光强度均高于未处理的细胞。对涂有包含肝素结合域的纤连蛋白40 kD片段的培养皿进行的细胞黏附研究表明，经IL-3处理的细胞的黏附性高于未处理的细胞。这些结果表明，在多能造血细胞中，IL-3调节膜相关蛋白聚糖的量，进而改变细胞与纤连蛋白肝素结合域的黏附相互作用。
