角蛋白19致敏的DC/CTL对MCF-7体外抑瘤作用的实验研究

Cytotoxicity of cytotoxic T lymphcytes induced by keratin 19-sensitized dendritic cells against MCF-7 cells in vitro

目的探讨体外经角蛋白19(K19)致敏的树突状细胞(DC)诱导的细胞毒T细胞(CTL)对MCF-7细胞株的抑瘤作用。方法经抗原多肽K19体外致敏外周血来源的DC诱导特异性CTL,流式细胞仪检测DC表面标志及细胞因子分泌,3H-TdR掺入法检测DC诱导CTL增殖,51Cr释放法测定CTL对MCF-7细胞的杀伤活性。结果外周血单个核细胞经体外扩增培养出可见树突状形状的DC,流式细胞仪检测细胞表面CD83、CD40、CD80及CD86高表达,混合淋巴细胞反应观察经K19致敏的DC刺激的自体淋巴细胞增殖明显较对照组高(P<0.01)。在同一效靶比时,K19致敏的DC诱导的CTL对MCF-7细胞的杀伤率与对照组比较差异有显著性(P<0.01),且随着效靶比增加,杀伤作用增强(P<0.01)。结论DC在体外经K19抗原致敏后,可诱导产生对MCF-7细胞有特异性杀伤作用的效应细胞杀伤MCF-7细胞,且随效靶比增加,杀伤力增强。

Objective To investigate the cytotoxicity of cytotoxic T lymphcytes （CTL） induced by keratin 19 （K19） -sensitized dendritic cells （DC） against MCF-7 cells in vitro. Methods DC isolated from peripheral blood mononuclear cells were cultured in vitro and sensitized by K l9 peptide to generate specific CTL. The phenotypes and intracytoplasm cytokine of DC were analyzed by flow cytometry. Mixed leukocyte responses were evaluated by ^3H-TdR incorporation assay. The T cells were generated by DC pulsed with K19 antigen and T cell cytotoxicity was measured by ^51Cr release assay. Results The DCs derived from peripheral blood mononuclear cells expressed high levels of CD40, CD86, CD80 and CD83. Mixed leukocyte responses induced by the DCs pulsed with K19 was stronger than that induced by naive DCs （P〈0.01）. The cytotoxicity rate of CTL induced by the sensitized DCs was higher than that of CTL induced by naive DCs （P〈0.01）. The cytotoxity activity was enhanced by increasing the effector/target ratio （P〈0.01）. Conclusion After sensitization with K19 antigen, the DCs can stimulate T cell proliferation and induce cytotoxicity activity against MCF-7 cells. Increased effector/target ratio may enhance the cytotoxity activity. Sensitized DCs possess the potential for amplification in immunotherapy of carcinoma.