抗原致敏树突状细胞诱导CTL杀伤K562细胞体外实验研究

In vitro study of cytotoxic T lymphocyte activation by antigen-loaded dendritic cells for killing of K562 cells

目的研究体外负载K562细胞冻融抗原的树突状细胞(DC)诱导细胞毒性T淋巴细胞(CTL)的特异性杀伤作用。方法联合应用细胞因子从外周血单个核细胞(PBMC)诱导培养出DC,在体外负载K562细胞冻融抗原。采用乳酸脱氢酶释放法,对比K562冻融抗原致敏DC组、未致敏DC组、淋巴细胞组、前列腺癌PC3冻融抗原致敏DC组分别激活的CTL对K562细胞的杀伤作用。结果培养出具有典型特征的DC;在效靶比为10:1及20:1时,K562冻融抗原致敏DC组诱导的CTL对K562细胞的杀伤率分别为55.9%±22.0%、90.2%±24.8%,均高于其他3组(P<0.05)。结论K562细胞冻融抗原致敏DC可诱导激活CTL,具有明显杀伤K562细胞作用,并具有特异性。

Objective To study the effect of dendritic cells （DC） stimulated with K562 cell lysate in inducing specific cytotoxic T lymphocytes （CTL） against K562 cells in vitro. Methods The DCs were derived from healthy human peripheral blood monocytes in the presence of granulocyte-macrophage colony-stimulating factor, interlenkin （IL）-4 and tumor necrosis factor （TNF） α. The T cells were stimulated by DCs loaded with freeze-thawed K562 cells and T-cell cytotoxicities were measured by lactate dehydrogenase （LDH） assay. Results The DCs could be successfully obtained from peripheral blood monocyte after the culture. Mixed lymphocyte reactions induced by the antigen-loaded DC were much stronger than those induced by human peripheral blood monocytes （P〈0.05）. At the effector to target ratio of 10：1 and 20：1, cytotoxicities against K562 cells by CTL derived from culture with the antigen-loaded DCs were the strongest （P〈0.05）. Conclusion CTL derived from DCs pulsed with K562 cell lysate show effecitive and specific cytotoxicity against K562 cells.