树突状细胞与尤文肉瘤细胞融合诱导抗肿瘤免疫应答的体外研究

In vitro antitumor immune response induced by fusion of dendritic cells and Ewing′s sarcoma cells

目的检测尤文肉瘤细胞A673和树突细胞(DC)融合构建的肿瘤疫苗对尤文肉瘤细胞株A673的杀伤作用。方法应用促融合剂PEG对尤文肉瘤A673细胞和从外周血单个核细胞(PBMC)诱生的树突细胞进行融合。利用细胞因子hGMCSF和hIL4从PBMC诱生DC,并对其表型进行流式细胞仪(FCM)分析,红色荧光染料PKH26标记A673细胞,绿色荧光染料PKH67标记DC,应用促融合剂PEG融合后光镜及电镜观察DC细胞和融合细胞形态,FCM检测融合效率,通过同种混合淋巴细胞反应检测其免疫刺激活性。通过IFNγELISA法产生细胞毒性T淋巴细胞(CTL)的量,通过51Cr细胞杀伤试验检测融合细胞对A673细胞的杀伤作用。结果FCM检测出从PBMC成功诱生出CD83、CD80、CD86及HLADR高表达的成熟DC。DCs/A673融合细胞的融合效率达到23%,同种混合淋巴细胞反应显示DCs/A673融合细胞有很强的免疫刺激活性。IFNγ分泌检测显示DCs/A673融合细胞组较对照组产生CTL水平显著增高。51Cr释放法检测融合细胞体外诱导抗原特异的CTL,融合细胞激活的CTL对肿瘤细胞系A673细胞的杀伤作用强于DCA673混合组、DC组、A673组的CTL(P<0.05),作用较对照各组显著增强。结论DC与A673细胞融合体外致敏自体T淋巴细胞能生成抗原特异CTL对尤文肉瘤细胞A673有一定的杀伤作用。

Objective Human Ewing sarcoma A673 cells and human peripheral blood-derived DCs were fused to induce an antitumor activity against human EW. Methods EW A673 cells and human peripheral blood-derived DCs were fused with polyethylene glycol(PEG). Results Mature DCs with highly expressed surface markers(CD80, CD86, CD83 and HLA-DR) were generated in vitro and flow cytometry. It showed that the highest fusion efficiency was 23.01%. T cell proliferation assay indicated that the novel dendritomas in fused DCs/A673 cells were the most potent in activation of autologous T cell proliferation. The IFN-γ assay showed that The IFN-γ secretion by CTLs activated by the novel dendritomas increased more than by other stimulators. CTL assay demonstrated that the novel dendritomas induced A673 cell-specific cytotoxic responses to lyse the A673 cells in the context of MHC classⅠ. Conclusion The data indicates that fusion of tumor cells with DCs is an attractive strategy to induce tumor rejection.