多药耐药K562/A02和敏感K562细胞来源的树突状细胞介导抗白血病效应对比研究

本研究探讨多药耐药(MDR)白血病K562/A02细胞和敏感K562细胞诱导树突状细胞(DC)分化及介导的抗白血病效应。采用慢性粒细胞白血病(CML)P170糖蛋白(Pgp)高表达的MDRK562/A02细胞、敏感K562细胞在含细胞因子GMCSF(1000U/ml)、IL4(500U/ml)和TNFα(100ng/ml)的RPMI1640完全培养液中诱导分化成DC,以光镜观察细胞形态、流式细胞术检测细胞表型,异基因混合淋巴细胞反应(alloMLR)检测T细胞增殖活性,MTT法测定细胞毒作用。结果表明:培养14天的K562/A02细胞和K562细胞均出现典型的DC形态特征,表达DC的相关分化抗原及共刺激分子CD1a、CD83、HLADR、CD80、CD86。alloMLR检测中,K562/A02DC较K562DC具有更强的刺激异基因T细胞增殖能力(P<0.05)。两种DC激活的CTL分别对K562/A02和K562细胞较HL60细胞具有显著的杀伤活性(P<0.01);更重要的是,K562/A02DC较K562DC激活的CTL对Pgp高表达的MDRK562/A02细胞、HL60/VCR细胞具有更强的细胞毒作用,杀伤活性分别为(40.7±1.3)%、(28.4±0.9)%(P<0.01)和(24.9±1.1)%、(8.2±0.7)%(P<0.01)。结论:Pgp高表达的MDR白血病细胞K562/A02和敏感K562细胞都可在GMCSF、IL4和TNFα作用下诱导分化为成熟DC,均可活化CTL产生特异的抗白血病效应;尤其K562/A02细胞来源的DC可介导针对Pgp高表达的多药耐药白血病的特异细胞毒作用。

Induction of Anti-leukemic Immunity of Dendritic Cells Derived from Multidrug Resistant Leukemia K562/A02 cells with High Expression of P-glycoprotein and Sensitive K562 cells

This study was aimed to investigate and compare the anti-leukemic effect mediated by dendritic cells (DC) derived from multidrug resistant (MDR) leukemia K562/A02 cells with high expression of p-glycoprotein (P-gp) and sensitive K562 cells. Multidrug resistant K562/A02 cell line and sensitive K562 cell line from chronic myeloid leukemia (CML) were induced for differentiating to DC in complete RPMI 1640 culture medium supplemented with GM-CSF (1 000 U/ml), IL-4 (500 U/ml) and TNF-alpha (100 ng/ml) for 14 days. The morphologic features of DC were observed by means of optical microscopy and the phenotype of DC was detected by flow cytometry. T-cell stimulating activity was determined by allogeneic lymphocyte reaction (allo-MLR). Cytotoxic activity was measured by MTT assay. The results indicated that DC derived from K562/A02 cells and K562 cells similarly showed the typical morphology of dendritic cell and expressed the surface differentiation antigens and costimulatory molecules CD1a, CD83, HLA-DR, CD80 and CD86 of DC. In allo-MLR, K562/A02-DC had a higher capacity to induce lymphocyte proliferation, compared with K562-DC (P < 0.05). K562/A02-DC and K562-DC could similarly generate specific cytotoxic activity against K562/A02 cells or K562 cells respectively, but low reactivity against HL-60 cells. More importantly, the cytotoxic activity mediated by K562/A02-DC was stronger than that by K562-DC against K562/A02 cells or HL-60/VCR cells (P < 0.01, respectively). It is concluded that functional DC can be differentiated from multidrug resistant leukemia K562/A02 cells as well as sensitive K562 cells in the presence of GM-CSF, IL-4 and TNF-alpha. Especially, DC derived from K562/A02 cells can induced a p-glycoprotein specific anti-leukemic immunity.