血小板第4因子对脐血CD_(34)^+细胞黏附功能的影响

Effect of platelet factor 4 on the adherence of cord blood CD_(34)^+ cells

目的 研究血小板第 4因子 (PF4 )对新鲜脐血CD34+ 细胞及扩增后脐血CD34+ 细胞黏附功能的影响 ;PF4对脐血CD34+ 细胞上的黏附分子CD4 9d及基质细胞趋化因子 (SDF 1)受体CXCR4的作用。方法 采用免疫磁珠法 (MACS)分选CD34+ 细胞 ,结晶紫染色测定细胞总黏附性 ,免疫荧光标记流式细胞仪测定CD4 9d及CXCR4的表达。结果 ①PF4可使新鲜脐血CD34 + 细胞总黏附性提高 ,且与剂量相关。②SDF 110 0ng ml可使脐血CD34+ 细胞总黏附性提高。③脐血CD34+ 细胞扩增 10d后未加PF4刺激的自发以及经SDF 1诱导的黏附功能开始下降 ,在扩增脐血CD34+ 细胞不同时间段加入 10 0ng mlPF4 ,脐血CD34 + 细胞对基质层的黏附能力始终保持较高水平 ,以 0天时脐血CD34 + 细胞黏附性为10 0 % ,扩增 14d时脐血CD34+ 细胞黏附性PF4组为 (2 6 2 .0 4± 6 4 .81) % ,同期对照组为 (6 4 .35±8 2 9) % ,经SDF 1诱导下扩增 14d的CD34+ 细胞的总黏附性PF4组为 (138.31± 32 .39) % ,同期对照组为 (6 7.6 6± 12 .4 4 ) %。④PF4 10 0ng ml作用于CD34 + 细胞时 ,CD4 9d 表达增长 13.0 2 % ,CXCR4表达增长17 33%。结论 PF4可使新鲜及扩增后的脐血CD34+ 细胞黏附功能增强 ,并促进CD4 9d及CXCR4的表达 ,提示PF4可能有助于脐血干细胞的归巢。

Objective To investigate the effects of platelet factor 4(PF4) on the adherence, and the expressions of adherent molecules CD_ 49d and CXCR4 and the receptor of SDF-1 of fresh and expanded cord blood CD_ 34 + cells. Methods CD_ 34 + cells were isolated from cord blood using MACS immune magnetic beads. The adherent ability was assayed by using crystal violet staining and the expression of adherent molecule CD_ 49d and CXCR4 by FACS. Results ①PF4 could increase the adherent ability of the fresh cord blood CD_ 34 + cells, the effect being positively correlated with the dose of PF4. ②SDF-1 at concentration of 100?ng/ml increased the adherent ability of the fresh cord blood CD_ 34 + cells. ③The spontaneous and the SDF-1 induced adherent ability of the cord blood CD_ 34 + cells began to decrease after being cultured for 10 days without PF4, while in the presence of PF4 at 100 ng/ml,the ability of the cord blood CD_ 34 + cell adhering to the stroma layer still remained at higher level. At day 14,the adherent ability was (262.04±64.81)% and (64.35±8.29)% in PF4 group and control group, respectively,if it was defined as 100% at day 0. SDF-1 at concentration of 100 ng/ml induced adherent ability was (138.31±32.39)% and (67.66±12.44)% in PF4 group and control group, respectively. ④The expression of CD_ 49d and CXCR4 increased 13.02% and 17.33%, respectively, when incubated with PF4. Conclusions PF4 could increase the adherent ability and promote the expression of CD_ 49d and CXCR4 of the cord blood CD_ 34 + cells, suggesting that PF4 promote the circulating stem cells homing to the marrow in the process of stem cells transplantation.