血小板第四因子对CD34+白血病细胞系KG1a粘附功能的影响

目的研究血小板第四因子(PF4)对CD34 白血病细胞系KG1a细胞与人脐静脉内皮细胞系ECV-304细胞之间粘附性及对多种粘附分子表达的影响。方法采用粘附实验、粘附阻断实验、MTT染色、半定量RT-PCR、免疫标记流式细胞仪测定等方法。结果穴1雪PF4可以增加KG1a细胞与ECV-304细胞之间的粘附作用。PF4与KG1a及ECV-304细胞同时孵育或与KG1a或ECV-304细胞单独孵育,均使KG1a细胞粘附能力增加。穴2雪抗粘附分子CD49d、CD106、CD54单克隆抗体可显著减少PF4对KG1a粘附的增加作用,而抗粘附分子CD62L、CD62E、CD62P单抗则对PF4的这种增加粘附的作用没有影响。穴3雪在PF4作用的3h内,半定量RT-PCR检测粘附分子CD49d、CD106、CD54mRNA表达水平有不同程度的上调。(4)PF4作用2h后,流式细胞仪分析显示KG1a细胞上的CD49d、ECV-304细胞上的CD54蛋白表达水平显著增加。结论PF4通过上调粘附分子的表达促进KG1a细胞的粘附功能。

Effect of platelet factor 4 on the adhesive property of leukemic CD34+ KG1a cell

Objective To study the effect of PF4on the adherence of leukemic CD34 KG1a cell to human umbilical vein endothelial cell line ECV-304cell and on the expression of adhesive molecules. Methods Adhesion assay and adhesion blocking assay were respectively applied to measure the effect of PF4and/or adhesion molecule monoclonal antibodies on the adhesion property of KG1a.The expressions of adhesion molecules were determined by RT-PCR and FACS analysis. Results The adhesion of KG1a cells to ECV-304was significantly enhanced in the presence of PF4.Such enhancement was also observed when KG1a or ECV-304cells were separately treated with PF4before interaction.The adhesion capacity of KG1a cells was reduced when cells were co-incubated with the blocking monoclonal antibodies(MoAbs)against CD49d,CD106,CD54,respectively.In contrast,MoAbs against CD62L,CD62P and CD62E had no such effect.During a period of3hours when KG1a or ECV-304cells were respectively incubated with PF4,the mRNA expressions of CD49d,CD54were up-regulated.Furthermore,when KG1a or ECV-304cells were incubated with PF4for2hours,respectively,the percentages of CD49d KG1a cells and CD54 ECV-304were increased significantly. Conclusion PF4can enhance KG1a cell adhesive capacity by increasing the expres-sions of adhesion molecules.