去岩藻糖GPC3抗体增强NK92细胞对肝癌细胞的杀伤效果

Defucosylation of anti-Glypican 3 antibody enhances the antibodydependent cell cytotoxicity of NK92 to hepatocellular carcinoma cells in vitro

目的去岩藻糖基化改造抗磷脂酰肌醇蛋白聚糖3(Glypican-3,GPC3)抗体GC33,并研究该抗体依赖的NK92细胞对肝癌细胞的杀伤效果。方法以岩藻糖基转移酶8(fucosyltransferase 8,Fut8)缺陷的中国仓鼠卵巢癌细胞(Chinese hamster ovary,CHO)表达去岩藻糖基化的GC33抗体,以野生型CHO细胞表达的GC33作为对照,通过梯度酶联免疫反应检测其与GPC3及FC gama receptorⅢa(FCGRⅢa)的结合活性;以NK92细胞作为效应细胞,检测去岩藻糖基化GC33抗体依赖的NK92细胞对GPC3阳性的肝癌细胞Hep G2和Huh 7细胞毒作用。结果去岩藻糖基化改造的GC33抗体保留了与野生型GC33抗体对GPC3相当的结合活性,其与FCGRⅢa的结合能力增强了7倍,增强天然杀伤细胞(natural killer cells,NK)对Hep G2和Huh 7细胞的细胞毒作用(antibody dependent cellular cytotoxicity,ADCC)。结论去岩藻糖基化增强了GC33抗体依赖的NK92细胞对肝癌细胞杀伤效果。

This study is aimed to defucosylate the anti-GPC3 antibody GC33 and investigate the antibody dependent cell cytotoxicity(ADCC) against hepatocellular carcinoma cell lines. Fut8-deficient CHO cells were used toexpressdefucosylatedGC33 antibody(GC33-fut-),andwild-typeGC33(GC33-wt)wereproducedbywild-typeCHO cells. The binding activity of GC33-fut-to GPC3 and FCGR Ⅲa was detected by enzyme-linked immunoreaction.NK92 cells were used as effector cells to detect the cytotoxicity of GC33-fut-to GPC3-positive hepatoma cells Hep G2 and Huh 7. Compared with GC33-wt, the GC33-fut-retained a considerable binding activity to GPC3,demonstrated a higher binding activity to FCGR Ⅲa by 7 folds, and higher ADCC effect to Hep G2 and Huh 7 cells.In conclusion, defucosylation of anti-GPC3 antibody enhances the ADCC to hepatocellular carcinoma cells.