细胞因子组合对受照射脐带血AC133^+细胞周期和早期凋亡的影响

EFFECTS OF CYTOKINE COMBINATIONS ON THE CELL CYCLE AND EARLY APOPTOSIS OF IRRADIATED UMBILICAL CORD BLOOD AC133^+ CELLS

采用免疫标记法,使用流式细胞仪测定受到2.5Gy6MV-X射线照射的脐带血AC133+细胞加细胞因子组合(IL-3+FL+SCF)在培养不同天数后的细胞周期及早期凋亡情况的变化。结果表明,新鲜分离的未受照的脐带血AC133+细胞在无细胞因子的短期液体培养体系中培养2天,99%的细胞处于G0/G1期;受照的脐带血AC133+细胞加细胞因子组合(IL-3+FL+SCF)培养不同天数后,脐带血AC133+细胞迅速进入增殖循环,在照后第3天,有近50%的细胞进入S期。脐带血AC133+细胞受照后不加细胞因子,培养48小时后,镜下观察到细胞全部死亡;加细胞因子组合(IL-3+FL+SCF)培养48小时后,有(38.0±6.8)%的受照的脐带血AC133+细胞被“救活”,且随着培养时间的延长,被“救活”的AC133+细胞又出现了增殖。因此,可认为细胞因子组合(IL-3+FL+SCF)对受照的脐带血AC133+细胞具有保护作用。

The cell cycle and early apoptosis of 2.5 Gy 6 MV-X my irradiated umbilical cord blood AC133^＋ cells cultured with cytokine combinations （IL-3 ＋ FL ＋ SCF） were immunolabelled and analyzed by flow cytometry at d O, 1, 2, 3 and 7. The result of flow cytometry analysis showed that majority of irradiated umbilical cord blood AC133^＋ cells were in G0/G1 phase of the cell cycle at d O. Under the influence of cytokine cembinations （IL-3 ＋ FL＋ SCF）, nearly 50% of cells were in S phase on 3rd day. AC133^＋ cells irradiated were in vitro incubated in the medium without cytokines, nearly all cells died by apoptosis. However, when we incubated cells with cytokine combinations （IL-3 ＋ FL ＋ SCF）, （38.0 ± 6.8）% of cells were saved from apoptosis at d 2. The more percent of saved AC133^ ＋ cells became to proliferate with the extention of culture. In short, cytokine combinations （IL-3 ＋FL ＋ SCF） could have a key role to protect irradiated cells and partially avoid induction of apoptosis by ionizing radiation in hematopoietics stem/ progenitor cells.