NDV7793活化的NK细胞对人肝癌HepG2细胞的杀伤及其机制研究

The killing effect and its mechanism of NK cells activated by NDV7793 on human hepatic carcinoma HepG2 cells

目的:研究NDV7793激活的NK细胞对人肝癌HepG2细胞的杀伤作用,并探讨可能的相关机制。方法:用免疫磁珠分离法分离人NK细胞,用乳酸脱氢酶释放法(LDH法)检测不同血凝单位(25.6Hu,51.2Hu,102.4Hu,204.8Hu,512.0Hu)的NDV7793刺激NK细胞后对人肝癌HepG2细胞的杀伤作用,分别用ELISA法和流式细胞术检测活化后的NK细胞分泌肿瘤坏死因子-α(TNF-α)的水平及细胞膜表面的TRAIL蛋白表达水平。结果:人外周血NK细胞分离纯度达(90.6±1.15)%;NDV7793能提高NK细胞对人肝癌HepG2细胞的杀伤作用,其杀伤效力(释放的LDH活力值)随着效靶细胞作用时间的增加及效靶细胞比的增大而增强;NDV7793能显著提高NK细胞TNF-α的分泌水平,其中204.8HuNDV7793刺激NK细胞12h后,TNF-α分泌水平达到高峰(0.184±0.01);102.4HuNDV7793刺激NK细胞16h后,NK细胞膜表面TRAIL表达达到高峰(22.77±1.8)%。结论:NDV7793能增强NK细胞对人肝癌HepG2细胞的杀伤作用,杀伤机制可能是和提高NK细胞分泌的TNF-α及上调细胞膜表面TRAIL蛋白有关。

Objective To observe the killing effect and its possible mechanism of NK cells activated by NDV7793 on human hepatic carcinoma HepG2 cells.Methods NK cells were purified by immunomagnetic microbead method.The killing effect of NK cells activated by various virus dosage（25.6 Hu,51.2 Hu,102.4 Hu,204.8 Hu,512.0 Hu） of NDV7793 on HepG2 cells was analyzed by LDH（Lactate dehydrogenase） releasing assay.Level of TNF-α produced by activated NK cells was detected by ELISA method,and the level of TRAIL protein expressed in the membrane of activated NK cells was examined by flow cytometry.Results The purity of NK cells separated from human peripheral blood was（90.6 ± 1.15）%.The killing effect of NK cells on HepG2 cells was enhanced by NDV7793,and was increased with virus dosage and incubation time.The level of TNF-α produced by NK cells was enhanced by NDV7793,and reached its summit（0.184 ± 0.01） when NK cells were stimulated by 204.8Hu of NDV7793 for 12 h.In addition,the level of TRAIL protein reached its summit [（22.77 ± 1.8） %] when NK cells were stimulated by 102.4Hu of NDV7793 for 16 h.Conclusions NDV7793 can enhance the killing ability of NK cells on HepG2 cells.TRAIL and TNF-α may play an important role in this effect.