趋化因子Fractalkine对小鼠实验性肝癌的基因治疗

Experimental gene therapy mediated by fractalkine (FK) for murine liver cancer

目的通过将趋化因子Fractalkine(FK)基因转染小鼠肝癌细胞株MM45T.Li,探讨FK用于诱导抗肝癌主动免疫的可行性。方法用脂质体将小鼠FK基因导入小鼠肝癌细胞株MM45T.Li,G418筛选抗性克隆。逆转录聚合酶链反应检测FK的表达,体内实验观察野生型及FK基因修饰肿瘤细胞的致瘤性, 组织病理学检测肿瘤中免疫细胞的浸润,流式细胞仪检测外周血中CD4+、CD8+ T淋巴细胞水平。结果逆转录聚合酶链反应检测发现G418筛选得到的转染FK的抗性克隆MM45T.Li-FK表达FK,而野生型MM45T.Li不表达FK。体内成瘤实验显示,与野生型瘤细胞相比,MM45T.Li-FK的成瘤率显著下降。MM45T.Li-FK所形成肿瘤中有明显的免疫细胞浸润,对照组肿瘤中免疫细胞的浸润较少。接种MM45T.Li- FK瘤细胞的小鼠,外周血中CD4+、CD8+ T淋巴细胞水平明显增高,与对照组相比差异均有统计学意义(P <0.01)。结论转染FK基因能促进机体的抗肝癌主动免疫反应。

Objective Chemokines play an important role in the infiltration of immune cells into tumor tissues. Anti-tumor immune response has been elicited in many tumor models by chemokine gene transfection. The aim of this study was to evaluate the possibility of inducing anti-hepatocellular carcinoma active immune response by transfection of mouse hepatocellular carcinoma cells MM45T.Li with chemokine FK gene. Methods Mouse FK gene was transduced into mouse hepatocellular carcinoma cells MM45T.Li using of liposome.G418-resistant clones were selected and the FK mRNA expression was detected by RT-PCR. In vivo experiments were performed to observe the tumorigenicity of wild type MM45T.Li and FK gene modified tumor cells. The immune cell infiltration in tumor tissues was detected histopathologically. The level of CD4^＋ and CD8^＋ T cells in peripheral blood were detected by FACS. Results RT-PCR detection showed that FK was expressed in FK gene transfected G418-resistant clones （MM45T.Li-FK）, but not in the wild type MM45T.Li. In vivo experiments the tumorigenicity of MM45T.Li-FK had decreased compared to the wild type MM45T.Li. In the tumor tissues from MM45T.Li-FK, many infiltrated immune cells were found, but few immune cells infiltrated into the tumor tissues from the controls. The level of CD4^＋ and CD8^＋ T cells had obviously increased in MM45T.Li-FK compared to the controls （P 〈 0.01）. Conclusions Transfection with chemokine FK gene can induce anti-hepatocellular carcinoma active immune response.