人肝癌细胞系HepG_2上清液抑制树突状细胞的免疫功能

Human hepatocarcinoma cell line HepG 2 supernate inhibit immune function of dendritic cells

目的研究人肝癌细胞系ＨｅｐＧ２与肝癌患者树突状细胞（ＤＣ）表面分子表达及ＤＣ免疫功能间的相关性。方法以间接免疫荧光法检测肝癌患者及正常人各１０例的外周血ＤＣ，同时测定了正常人外周血ＤＣ经人肝癌细胞系ＨｅｐＧ２上清液培养前后其表面人白细胞抗原ＤＲ（ＨＬＡＤＲ）及免疫分子Ｂ７表达水平，并进一步检测该ＤＣ免疫诱导能力。结果肝癌患者ＤＣ表面ＨＬＡＤＲ（６７±１６ＶＯＦ）及Ｂ７（６１±１１ＶＯＦ）表达水平及ＤＣ诱导Ｔ细胞增殖能力（３１００±１２０ｃｐｍ）明显低于经３种不同浓度上清培养的正常人ＤＣ（１１２±０９ＶＯＦ，Ｐ＜０．０５；１０±１３ＶＯＦ，Ｐ＜０．０１；６２００±９６ｃｐｍ，Ｐ＜００１）；正常人ＤＣ经ＨｅｐＧ２上清液培养后，其表面ＨＬＡＤＲ及Ｂ７表达水平（１０７±１４及９６±１２；７１±１６及７３±１１；３２±０８及２９±１１ＶＯＦ）及ＤＣ诱导Ｔ细胞增殖能力（５６８０±９３ｃｐｍ；４１００±１１０ｃｐｍ；３３７９±８１ｃｐｍ）均下降，且其与ＨｅｐＧ２上清液浓度（２５％、５０％、７５％）呈负相关。结论ＤＣ表面ＨＬＡＤＲ及Ｂ７表达水平下降与肿瘤细胞密切相关；肿瘤细?

Objective To study the relationship between tumor, dendritic cell (DC) and tumor bearing host. Methods The expression level of major histocompatibility complex Ⅱ (HLA DR) and B 7 on DC from normal adults ( n =10) was tested before and after incubation with human hepatocarcinoma cell line HepG 2 supernate and the ability of DC to induce immune response was evuluated. Results The expression level of HLA DR (6.7± 1.6 VOF) and B 7 (6.1±1.1 VOF) on DC from patients was obviously lower than that from normal adults (11 2±0.9 VOF, P <0.05; 12.0±1.3 VOF, P <0.05); the expression level of HLA DR and B 7 on DC from normal adults was down regulated (from 11.2±0.9 and 12.0±1.3 to 10.7±1.4 and 9.6±1.2; 7.1±1.6 and 7 3±1.1; 3.2±0.8 and 2.9±1.1 VOF) after incubation with HepG 2 supernate and was negatively correlated with the concentration of HepG 2 supernate (25%, 50%, 75%), the ability of DC to induce immune response was also decreased (from 6 200±90 cpm to 5 680±93 cpm, P >0.05; 4 100±110 cpm, P <0.05; 3 379±81 cpm, P <0.01) after incubation with HepG 2 supernate. Conclusion The immune function of DC is closely related with tumor cells which produce some cytokines to down regulate the expression of HLA DR and B 7 on DC thus inhibiting the immune function of DC and leading to further escape from the immune surveillance of tumor bearing host.