DC-CIK细胞的生物学活性及体外抗白血病作用的研究

本研究探讨树突状细胞（DC）对细胞因子诱导的杀伤细胞（CIK）增殖能力、免疫表型、分泌细胞因子水平及抗白血病细胞的作用。健康人外周血单个核细胞诱导DC和CIK，将DC与CIK共培养，以CIK细胞单独培养为对照。用台盼蓝活细胞计数计算细胞扩增倍数，MTT法测定杀伤活性，流式细胞术分析免疫表型，ELISA双抗体夹心法测定干扰素-γ（IFN-γ）、白介素-12（IL—12）的水平。结果表明：DC—CIK细胞增殖能力明显高于CIK细胞（P〈0．05）；DC、CIK细胞共培养后，CD3^＋CD8^＋、CD3^＋CD56^＋细胞比率较相同条件下CIK细胞组显著增多（P〈0．05）；共培养3天，DC—CIK细胞上清液中IL-12、IFN-γ水平均比CIK细胞单独培养的水平高（P〈0．01，P〈0．05）；在5：1—40：1的效靶比范围内，DC—CIK细胞对白血病细胞的杀伤率显著高于CIK细胞（P〈0．05），且杀伤率与效靶比呈正相关。结论：DC增加CIK细胞的增殖能力和抗白血病活性，有可能作为一种临床有效的抗白血病免疫治疗手段。

Biological Activity of DC-CIK Cells and Its Effect Against Leukemia Cells In Vitro

This study was aimed to investigate the effect of dendritic cells (DC) on the proliferation capability, immunophenotype changes, level of secreted cytokines and activity against leukemia of cytokine-induced killer (CIK) cells in vitro. DCs and CIK cells were induced from peripheral blood mononuclear cells of healthy volunteers. They were co-cultured meanwhile CIK cells were cultured alone as controls. Increased number of cells were counted by trypan-blue staining; the killing activity was detected by MTT assay; immunophenotype changes were analyzed by flow cytometry; the IL-12 and INF-gamma levels of the cultured supernatants were detected by ELISA kits. The results showed that the proliferation capability of DC-CIK cells was significantly higher than that of CIK cells (p < 0.05). Under the same condition, the ratio of double positive cells such as CD3(+) CD8(+), CD3(+) CD56(+) in CIK cells was significantly enhanced by co-cultured with DC cells (p < 0.05). The levels of IL-12 and INF-gamma in cultured supernatants of DC-CIK cells increased noticeably on day 3 as compared with CIK cells cultured alone (p < 0.01, p < 0.05). Within the effector-target ratio range between 5:1 to 40:1, the activity of DC-CIK cells against leukemia cells were much higher than that of CIK cells (p < 0.05), and this effect showed a positive correlation with the effector-target ratio. It is concluded that the proliferation capability of DC-CIK cells, the level of their secreted cytokines and their activity against leukemia cells are significantly higher than those of CIK cells. This research may suggest an approach for clinical immunotherapy against leukemia with DC-CIK cells.