IL-15对骨髓增生异常综合征患者CD34+细胞增殖、分化的影响

目的 探讨IL-15对体外培养的骨髓增生异常综合征(MDS)患者CD34+细胞增殖和分化的影响.方法 应用单克隆抗体(mAb)免疫磁珠系统分离CD34+细胞, 将实验分为加IL-15的实验组和不加IL-15的对照组, 分别用液体培养基和甲基纤维素半固体培养基培养.计数培养后的细胞数和CFU-E、BFU-E、CFU-GM和CFU-GEMM的集落形成数,并用MTT比色法检测IL-15对MDS 患者CD34+细胞增殖的抑制作用.用流式细胞术检测上述培养的细胞上各种表型分子CD33、 CD13、 CD71、 CD19和CD3表达的变化和细胞周期的改变.结果 11例MDS患者CD34+细胞的平均回收率为(75.4±5.2)%, CD34+细胞的纯度为(90.3±6.3)%.富集倍数为(83.1±12.5)倍.用MTT比色法检测表明, IL-15抑制CD34+细胞增殖的最佳剂量为20 μg/L, 最佳时间为8 d.将对照组及20 μg/L 的IL-15(实验组)分别与MDS患者的CD34+细胞共培养8 d, 进行细胞计数显示, 增殖倍数对照组为4.6倍, 实验组为6.3倍(P＜0.05, n＝5); 各祖细胞的集落形成率, 实验组均明显多于对照组.CD34+细胞上各种表型分子的表达率(除CD3外), 实验组均明显高于对照组.IL-15作用后, CD34+细胞的细胞周期中G1、S、G2期的比率均有明显变化, 与对照组相比较, 差异显著(P＜0.05, n＝7).结论 IL-15对MDS患者的CD34+细胞具有明显地促增殖和诱导分化的效应, 对MDS患者的治疗可能开阔了广大的前景.

Effect of IL-15 on the proliferation and differentiation of CD34+ cells from MDS patients

AIM: To explore the effect of IL-15 on proliferation and differentiation of CD34 (+) cells from MDS patients. METHODS: The CD34 (+) cells were separated by magnetic bead-activated cell sorter (MACS) system, and cultured in fluid or methylcellulose semisolid medium. MTT colorimetry was used to examine the inhibitory effect of IL-15 on the proliferation of MDS CD34(+) cells.The numbers of CD34(+)cells and colony formation of CFU-E, BFU-E, CFU-G, CFU-GEMM were counted. The expressions of CD33, CD13, CD71, CD19 and CD3 on cultured cells and the change of cell-cycle were analyzed by FCM. RESULTS: The recovery rate of CD34(+) cells was (75.4+/-5.2) %, the purity of CD34 (+) cells in positive fraction was (90.3+/-6.3) % and the enriched rate was (83.1+/-12.5) % in 11 MDS patients. MTT colorimetry detection showed that IL-15 could promote the proliferation of MDS CD34(+) cells. The optimal time of promotoing CD34(+) cell proliferation by IL-15 was 8 days and optimal dosage of IL-15 was 20 microg/L. After culture for 8 days with 0 microg/L IL-15 (control group) and 20 microg/L IL-15(experimental group), the number of CD34 (+) cells increased by 4.6-fold in control group and 6.3-fold in experimental group (P<0.05, n=5). The colony formation rates of experimental group were significantly higher than those of control group. The expression rates of the CD molecules (except for CD3) on CD34(+) in experimental group were notably higher than those in control group. As compared with control group, much more CD34(+) cells of experimental group were in G(2) and S phase of cell cycle(P<0.05, n=7). CONCLUSION: IL-15 can obviously promote the proliferation and differentiation of CD34(+) cells from MDS patients.