用移植物细胞模型评价CD_(34)^+细胞选择的效果

Evaluating effect of CD_(34) positive selection with the graft cell-model

目的 用移植物细胞模型评价免疫磁珠法进行CD34 阳性细胞选择的效果。方法 用荧光素Calcein AM标记靶细胞后分别种入细胞株、骨髓 (BM)或外周血干 (祖 )细胞 (PBSC)中以建立模型 ;用免疫磁珠法对模型进行CD34 阳性细胞选择 ,以流式细胞仪 (FCM)进行选择前后的效果评价。结果 模型Ⅰ (靶细胞加细胞系 )、Ⅱ (靶细胞加BM)、Ⅲ (靶细胞加PBSC)经选择后CD+ 34 细胞纯度分别为(94 54± 0 93) %、(68 1 5± 2 3 53) %、(57 1 8± 9 2 3) % ;富集倍数分别为 7 9± 0 1、1 0 4± 4 0、8 2±1 3 ;回收率分别为 (2 7 6± 3 8) %、(44 4± 1 3 1 ) %、(66 4± 1 3 9) %。模型Ⅱ中肿瘤细胞的清除率为(1 82± 0 51 )个对数级 (log) ;模型Ⅲ中T细胞的清除率为 (2 48± 0 38)log。结论 移植物细胞模型能简便、准确、快速地评价CD34 阳性细胞选择时的富集和净化作用。免疫磁珠法进行CD34 阳性选择具有良好的CD+ 34

Objectives The immunocytology staining and polymerase chain reaction (PCR) are usually used to evaluate the effect of the CD 34 positive selection in residual tumor cells While the two main methods showed a discrepancy between the number of tumor cells detected and the actual number remained, which may influence the accuracy of applicability and security of the purging methods To achieve an accurate evaluation of purging effects, a group of graft cell models was established and used to evaluate the efficacy of CD 34 positive selection with immunomagnetic beads (IMB) through 3 graft cell models Methods Cells labeled with Calcein AM were seeded into the cell line, bone marrow (BM) cells and peripheral blood stem cells (PBSC) to establish 3 cell models The CD 34 positive selections with IMB in 3 cell models were carried out and the efficacies were evaluated with the flow cytometry (FCM) Results After the CD 34 positive selection, the purities of CD + 34 cells in model Ⅰ,Ⅱ and Ⅲ were (94 54±0 93)%, (68 15±23 53)% and (57 18±9 23)% , respectively, which was significantly increased ( P <0 01, n = 3; P <0 05, n = 5; P < 0 05, n = 4 ) with the enrichment rates of (7 9±0 1), (10 4±4 0) and (8 2±1 3) folds The recovery rates of CD + 34 cells after the selection were (27 6±3 8)%, (44 4±13 1)% and(66 4±13 9)%, respectively In the model II, tumor cells of (1 82±0 51) log were effectively removed ( P < 0 02) However, a low level of tumor cells (0 13±0 13)% was still remained after the CD 34 positive selection T cells of (2 48± 0 38) log could be removed through the model III Conclusion Using the graft cell models to evaluate the effects of selection seems to be a convenient and quick approach with the high sensitivity and reliability After the CD 34 positive selection with IMB, the CD + 34 cells in grafts could be effectively enriched and T cells depleted However, a complete depletion of tumor cells in grafts could not be accomplished