人脐血来源树突细胞抗乙型肝炎病毒细胞免疫的体外实验研究

目的借助DC的强大抗原呈递能力,使其负载HBsAg后以激活HBsAg特异性的CTL,从而探索一种可有效活化机体抗HBV细胞免疫的免疫方式。方法从健康产妇分娩的胎儿脐血中分离出单个核细胞,在细胞因子组合的作用下诱导出DC,于体外负载HBsAg后,激活自体T细胞成CTL,于体外培养环境下检测其对表达HBsAg的靶细胞HepG2-S的杀伤效应。结果人脐血来源的单个核细胞可在多种细胞因子的作用下,被诱导为DC。DC在负载HBsAg后可于体外活化HBsAg特异性的CTL。效应细胞为负载HBsAg的DC活化脐血单个核细胞,靶细胞分别为不表达和表达HBsAg的HepG2,当效应细胞和靶细胞比为1:1时出现最大的杀伤效率,CTL对靶细胞的杀伤率分别为(16.36±6.42)%和(78.09±9.66)%,差别有统计学意义(P<0.01)。结论健康人脐血来源的DC,具有较强的抗原呈递功能,可在体外激活产生HBsAg特异性CTL,在表达HBsAg的靶细胞模型上可观察到一定杀伤效果,为人脐血来源DC用于抗HBV治疗进行了有益的探索。

A study on the anti-HBV effect of dendritic cell from human umbilical cord blood

Objectives Regarding the strong antigen-presenting abilities of dendritic cells (DC), this study was carried out based on the induction and proliferation of DC derived from human umbilical cord blood; the anti-HBV effect of cytotoxicity T lymphocytes (CTL) activated by those DC pulsed with HBsAg was also carried out to explore a new way to activate the HBsAg-specific CTL. Methods Cord blood was collected from the cord veins of normal placentae after Cesarean sections, from which cord blood mono-nuclear cells (CBMC) were separated through density gradient centrifugation. The CBMC were cultured in RPMI 1640 with a cytokine cocktail. Pulsed with HBsAg, the DC were prepared to activate the HBsAg-specific CTL among the CBMC. The cytotoxic effect of CBMCs activated by the DC primed with HBsAg was assayed through the killing of those HepG2-S target cells. Results Typical DC could be induced from CMBC cultured with a cytokine cocktail. DC pulsed by HBsAg activated HBsAg-specific CTL, which killed the target HepG2-S cells to some extent. Conclusion DC can be induced from CMBC with the cytokine cocktail and they show a strong antigen-presenting ability. DC produced in this way and pulsed by HBsAg can activate HBsAg-specific CTL in vitro. This might mean that it could be a new way to break the tolerance to HBV in chronic HBV-infected patients.