目的:探索肿瘤裂解物负载的DCs诱导活化的初始T细胞介导细胞免疫及活化的T细胞杀死肿瘤细胞的能力。方法:应用黏附法分离外周血中的淋巴细胞和单核细胞,应用GM-CSF+IL-4刺激单核细胞并诱导为iDCs,然后进行分组,应用相应的细胞因子等刺激iDCs转化为mDCs,其中肿瘤裂解物冲击DCs组:冻融抗原负载+TNF-α+IL-1β;无肿瘤裂解物冲击组:TNF-α+IL-1β。再分别用上述DCs与淋巴细胞进行混合培养以刺激混合淋巴细胞中的T细胞转化为细胞毒性T细胞,并进行分组,肿瘤裂解物冲击DCs组:肿瘤裂解物冲击DCs+IL-2+IL-7;无肿瘤裂解物冲击DCs组:无肿瘤裂解物冲击DCs+IL-2+IL-7;对照组:IL-2+IL-7。结果:成功获得iDCs,并高表达CD86、CD80和HLA-DR;相对于其它组,肿瘤裂解物冲击DCs组mDCs更显著上调CD83,且更有效地刺激淋巴细胞增殖;肿瘤裂解物冲击DCs组的cTLs也高表达CD95(Fas)且TNF-α和IFN-γ的表达水平显著提高(P〈0.05)。结论:肿瘤裂解物冲击DCs可有效促进T细胞活化、增殖;并显著增强相应CTLs的杀死靶细胞的能力,这为发展DCs+CTLs的免疫治疗肿瘤提供了一种新而且简便的生物治疗模式。
AIM: To evaluate the ability of dendritic cells (DCs) loaded with tumor lysate to initiate cell - mediated immune responses by stimulating naive T cells, and the efficiency of activated T cells to kill autologous tumor cells in vitro. METHODS: The peripheral blood lymphocytes and monocytes were obtained from the advanced renal cell carcinoma patient by conglutination method. The immature dendritic cells were generated in the presence of interleukin -4 (IL - 4 ) and granulocyte/macrophage colony - stimulating factor ( GM - CSF) from monocytes of healthy individuals. These cells were pulsed with tumor lysate or not. Induction of tumor - specific cytotoxic T lymphocytes (CTLs) response by mature dendritic cells (mDCs) was evaluated by the CD95 (Fas) expression assay through FCM and the cytotoxic assay a- gainst autologous human tumor cells. RESULTS : Human immature dendritic cells and T cells obtained from healthy donors were stimulated with tumor- pulsed dendritic cells. The immature dendritic cells were applied to the cytotoxicity assay against target autologous tumor cells. The CD95 (Fas) expression, IFN - γand TNF - α secreted by the CTLs in tumor lysate - plused DC group were higher than those of other groups. The capacity of the CTLs to kill autologous tumor cells was significantly different(P 〈 0. 05 ). Antigen- specific DCs vaccine can induce T cells activation and proliferation, thus we can obtain higher proportion of tumor specific cytotoxic T cells( CTLs), and enhance the CTLs to secret IFN - γand TNF -α . CONCLUSION : Our results indicate that monocyte - derived human dendritic cells pulsed with tumor lysate could induce the specific antitumor effect against autologous tumors . This in vitro model offers a new and simple approach to the development of DC + CTL -based immunotherapy.