重组腺相关病毒转导人树突状细胞体外诱导抗肝癌免疫应答

目的 探讨携带甲胎蛋白基因的重组腺相关病毒(rAAV-AFP)转导人树突状细胞(DC)体外诱导抗肝癌免疫应答.方法 分离健康志愿者外周血单核细胞,贴壁细胞转导rAAV-AFP后,在粒细胞巨噬细胞集落刺激因子(GMCSF)和白细胞介素4(IL-4)的联合作用下,诱导分化为DC.用四唑盐(MTS)比色法检测AAV-AFP转导的DC(AAV-AFP+DC)刺激自体T细胞增殖的能力;流式细胞仪检测DC表型、AAV-AFP转导DC的效率以及AAV-AFP+DC激活的T细胞干扰素γ(IFN-γ)和IL-4的分泌;乳酸脱氢酶(LDH)释放细胞毒试验检测AAV-AFP+DC刺激的T细胞对AFP阳性肝癌细胞系的杀伤活性.结果 AAV-AFP转导的DC高表达人类主要组织相容性复合体Ⅰ类分子(HLA Ⅰ,97.12%)、HLAⅡ(97.32%)、CD80(38.94%)、CD83(60.84%)、CD86(98.14%)等DC的典型表面标记;AAV-AFP转导后,81.2%的DC表达AFP;AAV-AFP+DC能够有效地刺激自体T细胞增殖、活化,激活后19.84%的CD4+T细胞和18.65%的CD8+T细胞能够分泌IFN-γ而不分泌IL-4,对AFP阳性的肝癌细胞系HepG2、BEL7402杀伤率分别为56.45%和78.94%.结论 AAV-AFP+DC体外能够诱导出有效地抗AFP阳性肝癌免疫应答,为AFP表达阳性的肝癌患者的主动性免疫治疗提供了实验依据.

Abstract：

Objective To investigate the generation of antitumor response against hepatocellular carcinoma by in vitro transduction of dendritic cells (DC)with recombinant adeno-associated virus expressing α-fetoprotein (rAAV-AFP). Methods Peripheral blood mononuclear cells were isolated from healthy volunteers. Adherent peripheral blood mononuclear cells were transduced with AAV-AFP and cultured in the presence of granulocyte macrophage colony stimulating factor and interleukin-4 to generate dendritic cells.MTS assay was used to measure the ability of DC transduced with AAV-AFP ( AAV-AFP + DC) to stimulate the proliferation of T cell. The phenotype and AFP protein expression of DC and the secretion of IFN (interferon)-γ and IL (interleukin)-4 by T cells were detected by flow cytometry. The killing efficacy of cytotoxic T lymphocytes (CTL) activated by AAV-AFP + DC against AFP positive hepatocellular carcinoma cell lines was detected by lactate dehydrogenase (LDH) release assay. Results AAV-AFP + DC expressed HLA Ⅰ (97. 12%), HLAⅡ (97.32%), CD80(38.94%), CD83(60.84%)and CD86(98. 14%). AFP was secreted by 81.2% of AAV-AFP + DC. And it could stimulate effectively the proliferation of T cell.19. 84% of CD4 + T cells and 18.65% of CD8 + T cells activated by AAV-AFP + DC produced IFN-γbut not IL-4 and showed distinct killing activities against AFP positive hepatocellular carcinoma cell lines HepG2 (56. 45% ) and BEL7402 (78. 84% ). Conclusion AAV-AFP + DC can elicit distinct antitumor responses against AFP positive hepatocellular carcinoma cell lines so as to provide a basis for further researches on the clinical application of AAV-AFP + DC in the treatment of hepatocellular carcinoma.