rhG-CSF体内诱导造血干细胞移植供者外周血T细胞免疫耐受的初步研究

本研究探讨rhG CSF体内应用诱导健康供者外周血T淋巴细胞免疫耐受的机制。对 15例病人进行了外周血干细胞移植 ,借助三色和四色荧光标记技术 ,对供者rhG CSF动员前后外周血T细胞上共刺激分子CD2 8的表达、树突状细胞 (DC)亚群以及CD8 CD2 8- 抑制性T细胞的变化进行了流式细胞术测定。结果显示 ,rhG CSF动员后外周血采集物中CD3 CD2 8 细胞的相对数显著升高 (P <0 .0 1) ,CD2 8表达的平均荧光强度明显降低 (P<0 .0 5 ) ;CD8 CD2 8 细胞的相对数也显著升高 (P <0 .0 1)。但在T细胞上CD2 8总体表达的相对荧光强度无变化 (P >0 .0 5 )。动员前外周血中DC2的含量明显低于正常骨髓 (P <0 .0 1) ,动员后采集物中DC2的数量较动员前和正常骨髓均有显著增加 (P <0 .0 1) ,DC的数量也显著增加 (P <0 .0 1) ,DC1 DC2比值倒置 (P <0 0 1) ,而DC1在动员前后无变化 (P >0 .0 5 )。CD8 CD2 8- 细胞占有核细胞的百分比较动员前明显增加 (P <0 0 5 )。结论 :rhG CSF体内应用后 ,采集物中DC2和CD8 CD2 8- 抑制性T细胞数量的增加可能是外周血T细胞免疫耐受产生的重要机制。

Peripheral Blood T Cell Immuno-Tolerance in PBSCT Donors Induced by rhG-CSF in vivo

The study was aimed to investigate the mechanism of T cell tolerance in human peripheral blood induced by rhG-CSF in vivo. Dendritic cell (DC) subsets, CD8(+)CD28(-) T suppressor cells and the expression of CD28 on T cells of peripheral blood before and after mobilization were analyzed by multicolor flow cytometry. The results showed that after mobilization by rhG-CSF in vivo, the relative counts of CD3(+)CD28(+) cells increased significantly (P < 0.01), and so did the CD8(+)CD28(+) cells (P < 0.01). The mean fluorescence intensity of CD28 expression on CD3(+) cells decreased greatly (P < 0.05), but there were no significant changes of the relative fluorescence intensity of CD28 overall expression on T cells (P > 0.05). The percentages of DC2 before mobilization were significantly lower as compared with normal bone marrow (P < 0.01). After using rhG-CSF, the DC2 count was significantly higher in the apheresis graft than in peripheral blood and bone marrow before mobilization (P < 0.01), while the DC1:DC2 ratios were lower (P < 0.01) and there was no significant difference of DC1 before and after mobilization (P > 0.05). The percentages of CD8(+)CD28(-) T suppressor cells increased significantly also after mobilization (P < 0.05). It is concluded that the higher numbers of DC2 and CD8(+)CD28(-) T suppressor cells in peripheral blood grafts may contribute to the ability of tolerance in peripheral blood T cells induced by rhG-CSF in vivo.