Lu Shi-hong, Liu Yong-jun, Lu Min, Feng Yi, Li Wen-ying, Cai Ying-lin, Han Zhong-chao
National Laboratory of Experimental Hematology, Institute of Hematology, CAMS, PUMC, Tianjin 300020, China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2002 Feb;24(1):25-9.
To study the effects on adherence of hematopoietic stem/progenitor cells, PF4 was assessed alone or in combination with IL-3 for effects on the total adherence and various kinds of adhesion molecules of KG1a cells as well as actin polymerization in KG1a cells.
The total adherence was assayed by crystal violet dye staining. The adhesion molecule expression was determined by FACS analysis. These adhesion molecule monoclonal antibodies individually blocked total adherence by MTT. F-actin content was monitored by fluorospectrophotometry.
100 ng/ml PF4 could increase the total adherence of KG1a cells by 80%. 20 ng/ml IL-3 could increase the total adherence of KG1a cells by 96%. When PF4 and IL-3 were combined, the total adherence could be promoted by 97%. Exposure of 1 x 10(6) cells/ml of KG1a cells to 100 ng/ml PF4 the 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 for 34%-43%. Similar phenomenon was observed when IL-3 was added onto KG1a cells. Further study found that PF4 induced actin polymerization of KG1a cells.
Our study indicated that PF4 promoted total adherence, as well as several adhesion molecule expression and actin polymerization of KG1a cells. The results suggest that PF4 may have therapeutic utility along with other cytokines by enhancing the total adhesion of hematopoietic stem/progenitor cells to promote the homing.
为研究对造血干/祖细胞黏附的影响，单独评估了PF4以及PF4与IL-3联合使用对KG1a细胞总黏附、各类黏附分子以及KG1a细胞中肌动蛋白聚合的影响。
通过结晶紫染料染色测定总黏附。采用流式细胞术分析确定黏附分子表达。这些黏附分子单克隆抗体通过MTT单独阻断总黏附。通过荧光分光光度法监测F-肌动蛋白含量。
100 ng/ml PF4可使KG1a细胞的总黏附增加80%。20 ng/ml IL-3可使KG1a细胞的总黏附增加96%。当PF4与IL-3联合使用时，总黏附可提高97%。将1×10(6) 个细胞/ml的KG1a细胞暴露于100 ng/ml PF4时，KG1a细胞总黏附的增加由PECAM-1（CD31）、CD44、LFA-1（CD11a）和Mac-1（CD11b）介导，而非由P-选择素（CD62P）和E-选择素（CD62E）介导。这些黏附分子单克隆抗体可单独阻断总黏附的34%-43%。在KG1a细胞上添加IL-3时也观察到类似现象。进一步研究发现PF4可诱导KG1a细胞的肌动蛋白聚合。
我们的研究表明，PF4可促进KG1a细胞的总黏附、多种黏附分子表达以及肌动蛋白聚合。结果提示，PF4可能与其他细胞因子一起通过增强造血干/祖细胞的总黏附来促进归巢，从而具有治疗用途。
