论文部分内容阅读
为了探讨HBV感染后Tim-3/Galectin-9信号通路对NK细胞功能的影响,我们首先利用RT-PCR和FACS法比较四种不同肝癌细胞系HepG2、HepG2-N1、HBV阳性的HepG2.2.15和HepG2-HBV细胞表面Galectin-9的表达差异,继而观察NK细胞对不同Galectin-9表达水平的靶细胞的杀伤效率和产生IFN-γ能力的变化,并采用Annexin V/PI双染法观察Galectin-9对NK细胞凋亡的影响。结果显示,HBV阳性的HepG2-HBV和HepG2.2.15细胞表面Galectin-9的表达明显高于HepG2和HepG2-N1细胞,NK细胞对高表达Galectin-9的HepG2-HBV和HepG2.2.15细胞的杀伤能力明显低于低表达Galectin-9的HepG2细胞,产生IFN-γ的能力亦明显降低。Galectin-9重组蛋白抑制NK细胞的杀伤效率并促进其发生凋亡;阻断Tim-3/Galectin-9信号可在一定程度上恢复NK细胞的功能。结果表明,HBV感染可通过诱导肝细胞表面Galectin-9的表达抑制NK细胞杀伤和IFN-γ分泌能力,并促使其发生凋亡,这可能是HBV感染易造成机体细胞免疫耐受的重要原因之一。
To investigate the effect of Tim-3 / Galectin-9 signaling pathway on NK cell function after HBV infection, we first compared HepG2, HepG2-N1, HBV positive HepG2.2.15 HepG2-HBV cell surface Galectin-9 expression differences, followed by observation of NK cells on different Galectin-9 expression levels of target cells killing efficiency and IFN-γ production capacity changes, and Annexin V / PI double staining observed Galectin- 9 on NK cell apoptosis. The results showed that the expression of Galectin-9 on HepG2-HBV and HepG2.2.15 cells was significantly higher than that on HepG2 and HepG2-N1 cells. The cytotoxicity of NK cells to HepG2-HBV and HepG2.2.15 cells highly expressing Galectin-9 Obviously lower than HepG2 cells with low expression of Galectin-9, the ability to produce IFN-γ also significantly reduced. Galectin-9 recombinant protein can inhibit the killing efficiency of NK cells and promote the apoptosis of NK cells. Blocking Tim-3 / Galectin-9 signal can restore the function of NK cells to a certain extent. The results showed that HBV infection could induce NK cell killing and IFN-γ secretion by inducing the expression of Galectin-9 on the surface of hepatocytes and induce apoptosis, which may be one of the important reasons that HBV infection can easily lead to cell immune tolerance one.