递呈乳腺癌细胞MCF-7肿瘤抗原的树突状细胞对T细胞的激活

T lymphocytes activation by dentritic cells loaded with the tumor antigen from breast cancer cells MCF-7

目的:在体外利用细胞因子的诱导获取树突状细胞(DC),并观察递呈肿瘤抗原后的成熟DC对T细胞的激活作用。方法:健康人外周血单个核细胞(PBMC)在体外用细胞因子诱导获取DC,并经乳腺癌细胞MCF-7肿瘤细胞裂解物体外冲击,再以1∶5的比例将致敏DC与T细胞共同孵育5d并共同作为效应细胞,通过FACS分析T细胞激活前后的表型变化以及MTT试验观察体外特异性肿瘤杀伤效果。结果:DC在细胞因子的诱导下7d后,形态学表现为伸出许多伪足样突起,在摄取抗原后可见内吞样小泡。FACS检测呈现成熟DC的标志,CD40、CD83、CD80、CD86和HLA-DR等高表达。另外,未经成熟DC激活的T淋巴细胞以辅助性T细胞(Th)为主,CD4+52.1%,CD8+仅22.1%;而经成熟DC激活的T淋巴细胞以杀伤性T细胞(Tc)为主,CD4+32.6%,CD8+64.2%。同时,MTT试验证实经递呈MCF-7肿瘤抗原的DC激活了细胞毒性T淋巴细胞(CTL),并对MCF-7具有特异性肿瘤杀伤作用。结论:体外递呈肿瘤抗原MCF-7的成熟DC对T细胞具有激活作用,并产生肿瘤特异性CTL。

OBJECTIVE：To explore T lymphocytes acti-vation by dentritic cells （DCs）induced by several kinds of cyto-kine and loaded with the tumor antigen. METHODS： DCs de-rived from the heathy donor＇s peripheral blood monocyte（PB-MC） were isolated and induced by the cytokine in vitro, and then were pulsed with lysates from breast cancer cells MCF-7.The DCs were co-incubated with T cells（DC ： T cell = 1 ： 5）for 5 days. T cells were analysed by fluorescence-activated cell sorter（FACS）. MTT assay was used to estimate specific cyto-toxic activity to MCF-7. RESULTS：The mature DCs sticked out many pseudopods on the 7th day . Some endosomal vesiclescould be seen after tumor antigen was captured. By FACS a-nalysis, the mature DCs＇ surface marker were upregulated compared with immature DCs, including CD40, CD83, CDS0, CD86 and HLA-DR. T cells were composed of 52.1% CD4^＋ and 22.1% CD8^＋. However, T cell induced by tumor cell-loaded DC consisted of 32.6% CD4^＋ and 64.2% CD8^＋ . MTT assay revealed that the cytokine-driven DCs pulsed with whole tumor lystate induced a strong specific CTL cytotoxicity to MCF-7. CONCLUSION： In vitro T lymphocytes can be activa-ted by the mature DCs loaded with the tumor antigen and pro-duce the activation of tumor-specific CTL against target cells.