肝癌细胞Fas-FasL途径反击免疫细胞

Immune Counterattack Mechanisms by Fas-FasL Pathway of Hepatocellular Carcinoma

为了探讨肝癌细胞反击肿瘤浸润淋巴细胞(TIL)的机制,在体外进行肝癌细胞和TIL混合培养后,检测两种细胞FasL、Fas、caspase-8基因的表达情况,以及肿瘤细胞反击时TIL凋亡比例的变化。将肝癌细胞与TIL按照不同的比例共培养后,流式细胞术检测TIL凋亡率;实时荧光定量PCR检测肝癌细胞与TILFasL、Fas和caspase-8基因的表达情况;以及Western印迹检测FasL、caspase-8的表达情况。不同浓度的肝癌细胞与TIL共同培养48h后,随着肝癌细胞接种浓度的增加,TIL凋亡率明显增加(P<0.01)。与正常人肝细胞相比,人肝癌细胞FasLmRNA表达含量明显增高(P<0.01)。与人肝癌细胞共同培养24h后,TILFas、caspase-8基因mRNA的表达也明显升高;TILcaspase-8的表达也明显升高。结果表明,肝癌细胞可以通过Fas系统诱导TIL发生凋亡,这为肝癌的免疫逃逸和肿瘤反击机制提供了依据。

To investigate the mechanisms of hepatic cancer cells inducing apoptosis of tumor-infiltrating lymphocytes （TILs） in vitro, hepatic cancer cells were co-cultured with TILs in different effector-taget ratio. Apoptotic ratios of TILs were screened by flow cytometry （FCM）. Expression levels of mRNA of FasL, Fas and caspase-8 in hepatic cancer cells and TILs were tested by real time PCR. FasL and caspase-8 expression were screened by immunoblotting. After co-culturing with hepatic cancer cells, apoptotic ratios of TILs were increased with the ascending number of hepatic cancer cells （P〈0.01）. Compared with the normal hepatic cells from healthy donors, FasL mRNA expression level of hepatic cancer cells was significantly increased （P〈0.01）. After 24 hour＇s co-culturing with hepatic cancer cells, Fas and caspase-8 mRNA expression levels of TILs were significantly higher than before co-culturing （P〈0.05）. After co-culturing with hepatic cancer cells, caspase-8 expression of TILs was significantly higher than before. The results suggested that hepatic cancer cells could induce apoptosis of TILs through Fas system, providing a evidence for the metastasis and counterattack of hepatic cancer cells.