肝脏肿瘤细胞诱导T淋巴细胞PD-1表达及功能研究

目的研究肝脏肿瘤细胞系细胞HepG2细胞与HepG2．2．15细胞对T淋巴细胞程序性死亡分子1（PD-1）表达的影响及PD-1的作用。方法HepG2细胞、HepG2．2．15细胞分别和Jurkat细胞共同培养后，标记流式抗体，流式细胞检测仪检测Jurkat细胞PD-1的表达，ELISA检测并比较阻断组与对照组培养上清中细胞因子含量，单核细胞直接细胞毒性测定法检测并比较阻断组与对照组T淋巴细胞杀伤能力即OD值的改变。结果肝脏肿瘤细胞能诱导T淋巴细胞PD-1的表达，共培养2d时表达率分别为16．17％±2．5％（HepG2细胞）和17．43％±2．2％（HepG2．2．15细胞）；阻断组培养上清中IL-2、IFN-γ、IL-10浓度分别为202．9±53．0pg/ml、88．6±4．6pg/ml和63．7±13．4pg／ml，均明显高于对照组（102．9±53．0pg/ml、39．3±4．2pg/ml和34．6±13．7pg/m1），P〈0．05；阻断组Jurkat细胞对HepG2．2．15细胞杀伤的OD值为0．29±0．06，明显高于对照组（0．19±0．09），P〈0．05。结论肝脏肿瘤细胞能诱导T淋巴细胞PD-1的表达；阻断PD-1／PD—L1能提高T淋巴细胞分泌细胞因子的量和杀伤能力。

PD-1 expression of T lymphocytes induced by hepatoma cells and the function of PD-1

Objective To investigate the differences in programmed cell death-1 （PD-1） expression of T lymphocytes induced by HepG2 cells and HepG2.2.15 cells and the function of PD-1 in T lymphocytes. Methods HepG2 cells and HepG2.2.15 cells were cocultured with Jurkat cells. The levels of PD-1 were detected by flow cytometry （FCM）. The number of cytokines in culture supernatants was measured using enzyme-linked immunosorbent assay （ELISA） and compared between the blocking group and the control group. The optical density （OD） value of cytotoxic action of T lymphocytes was determined using mono-nuclear cell direct cytotoxicity （MTT） assay and compared between the two groups. Results The expression rates of PD-1 in Jurkat cells were 16.17% ± 2.5% and 17.43% ± 2.2% after the co-culture with HepG2 cells and HepG2.2.15 cells for 2 days, respectively. The levels af IL-2, IFN-γ and IL-10 in the culture supernatants in the blocking group were significantly higher than those in the control group （202.9 ± 53.0 pg/ml and 102.9 ±53.0 pg/ml, 88.6 ± 4.6 pg/ml and 39.3± 4.2 pg/ml, 63.7 ±13.4 pg/ml and 34.6 ± 13.7 pg/ml, respectively, P〈0.05）. The OD value of cytotoxic action on HepG2.2.15 cells in the blocking group was significantly higher than that in the control group （0.29 ±0.06 and 0.19± 0.09, P〈0.05）. Conclusions The PD-I expression in Jurkat cells can be induced by hepatoma cells. Blocking PD-1/PDL-1 expression can increase the number of cytokines and enhance cytotoxic action.