人脐血树突状细胞体外诱导抗白血病细胞毒效应

Induction of Anti-leukemic Cytotoxicity by Dendritic Cells Derived from Human Cord Blood In Vitro

为了体外观察树突状细胞 (DC)诱导的抗白血病细胞毒效应 ,采用细胞因子组合体外扩增培养脐血单个核细胞 (CBMNC) ,对产生的DC进行形态学观察、免疫表型检测和功能鉴定 ;用DC制备细胞毒T淋巴细胞 (CTL)和51Cr释放法测定CTL的溶靶细胞毒性。结果表明 :CBMNC中T细胞亚群与成人外周血相似 ;CD1a阳性细胞含量极少 ,仅为 (0 .4 1± 0 .0 9) % ;在DC扩增培养过程中 ,DC形态发生明显变化 ,胞体变大 ,形态不规则 ,有的细胞出现毛刺状突起 ,有的细胞出现粗大树根状突起 ;在培养 15天时 ,细胞群中CD1a阳性细胞达 (2 8.4± 3.5 5 ) % ,有 (6 3.6 7± 2 3.33) %的细胞表达CD86 ,(8.7± 1.4 9) %的细胞表达CD83,(32 .5± 1.5 3) %的细胞表达HLA DR ;产生的DC对异基因淋巴细胞具有明显的增殖刺激作用 ;经冻融的HL 6 0全细胞抗原脉冲的DC致敏自体T淋巴细胞产生的CTL对HL 6 0细胞具有特异性细胞毒效应。结论 :本研究中的脐血DC培养体系能产生较高含量的DC ,脐血DC在体外能诱导产生抗白血病细胞毒效应。

The aim was to investigate the cytolytic activity of cytotoxic T lymphocytes (CTL) induced by dendritic cells (DC) derived from human cord blood in vitro. Human cord blood mononuclear cells (CBMNC) were cultured in vitro with addition of various cytokines. DC was confirmed by morphology,immune phenotype and capacity of stimulating MLR (mixed lymphocyte reaction). CTL were generated through the co-culture of autologous T lymphocytes and DC. 51 Cr -release assays were performed for the measurement of cytotoxicity of CTL. The results showed that distribution of the subgroups of T lymphocytes in CBMNC was similar to that in adult peripheral blood. The percentage of CD1a-expressing cells in CBMNC was very low,merely (0.41±0.09)%. During culture,DC became larger and more irregular in shape. Spiny dendrites or multiple cell processes in morphology emerged on the surface of DC. Among the cell populations at 15 days of culture,there were (28.4±3.55)% of CD1a-expressing cells,(63.67±23.33)% of CD86-positive,(8 7±1 49)% of CD83-positive and (32.5±1.53)% of HLA-DR-positive cells. DC derived from CBMNC is capable of stimulating the proliferation of allogeneic lymphocytes in MLR. CTL derived from autologous T lymphocytes induced by dendritic cells pulsed with lysates of HL-60 cells,possessed specific cytolytic effects against HL-60 cells. In conclusions,relatively high percentage of CD1a-expressing cells can be generated in culture system of this study. DC derived from cord blood is able to induce the production of anti-leukemic CTL in vitro.