PF4对造血干/祖细胞系KG1a总粘附性、粘附分子表达及细胞骨架蛋白聚合的作用

The CXC-chemokine Platelet Factor 4(PF4)Increases KG1a Cells Adherence and Modulates Actin Polymerization of KG1a Cells

目的研究ＰＦ４单用及与ＩＬ－３联合应用对造血干／祖细胞系ＫＧ１ａ总粘附性、粘附分子表达及细胞骨架蛋白聚合的影响。方法采用结晶紫染色、免疫标记流式细胞仪测定、ＭＴＴ、荧光分光光度等方法。结果１．单用１００ｎｇ／ｍｌ ＰＦ４作用于ＫＧ１ａ细胞时，ＫＧ１ａ细胞总粘附性增长８０％，单用２０ｎｇ／ｍｌ ＩＬ－３作用于ＫＧ１ａ细胞时，ＫＧ１ａ细胞总粘附性增长９６％，ＰＦ４与ＩＬ－３联合作用于ＫＧ１ａ细胞时，ＫＧ１ａ细胞总粘附性增长９７％。２．ＰＦ４作用于ＫＧ１ａ后，ＣＤ３１、ＣＤ４４、ＣＤ１１ａ、ＣＤ１１ｂ表达分别增加了２１％、２２％、１７％、１８％，较前均有显著性（Ｐ＜０．０５＝，而ＰＦ４对ＫＧ１ａ细胞的ＣＤ６２Ｐ、ＣＤ６２Ｅ表达无影响；ＰＦ４与ＩＬ－３联合作用于ＫＧ１ａ时，ＣＤ３１、ＣＤ４４、ＣＤ１１ａ、ＣＤ１１ｂ表达并没出现互相促进作用。３．分别用抗ＣＤ３１、ＣＤ４４、ＣＤ１１ａ、ＣＤ１１ｂ等单克隆抗体阻断ＫＧ１ａ粘附分子时，对ＰＦ４引起的ＫＧ１ａ粘附性分别下调了３９％、４３％、３４％、３８％。４．ＰＦ４、ＩＬ－３作用ＫＧ１ａ细胞时，能够引起ＫＧ１ａ细胞肌动蛋白的聚合。结论ＰＦ４可刺激早期的白血病性造血干／祖?

Objective To study the effects on adherence of hematopoietic stem/progenitor cells,PF4was assessed alo ne or in combi nation with IL-3for effects on the total adherence and various kinds of adhesion molecules of KG1a cells as well as actin polymerization in KG1a cells.Methods The total adherence was assayed by crystal violet dye staining.The adhesion molecule expression was determ-ined by FACS analysis.These adhesion molecule monoclonal antibodies individually blocked total adhere nce by MTT.F-actin content was monitored by fluorospectrophotometry.Results100ng/ml PF4could increase the total adherence of KG1a cells by80%.20ng/ml IL-3could increase the total adheren ce of KG1a cells by96%.When PF4and IL-3were combined,the total adherence could be promoted by97%.Exposure of1×10 6 cells/ml of KG1a cells to100ng/ml PF4the increased total adherence of KG1a cells was mediated by PECAM-1(CD31),CD44,LFA-1(CD11a)and Mac-1(CD11b)but not by P-selectin(CD62P)and E-selectin(CD62E).These adhesion molecule monoclonal antibodies could individually block total adherence for34%～43%.Similar phenomenon was observed when IL-3was added onto KG1a cells.Further study found that PF4induced actin polymerization of KG1a cells.Conclusions Our study indicated that PF4prom oted total adherence,as well as several adhesion molecule expression and actin polymerization of KG1a cells.The results suggest that PF4may have therapeutic utility along with other cytokines by enhancing the total adhesion of hematopoietic stem/progenitor cells to promote the homing.