肝癌细胞裂解物负载的树突状细胞来源的exosomes制备及其抗肝癌免疫活性的研究

摘要

目的:制备一种比单纯源于DC的、更有效的新型治疗肝癌的DC来源的exosomes瘤苗,进而探讨其生物学特性、免疫学功能及抗肿瘤免疫活性.方法:用细胞因子诱导培养树突状细胞(dendritic cell,DC),将肝癌细胞HepG2裂解物负载DC后,提取exosomes.透射电镜观察exosomes形态,流式细胞术检测exosomes蛋白分子的表达;其后应用exosomes直接刺激效应淋巴细胞,MTT法检测CTL对靶细胞HepG2的杀伤活性.结果:透射电镜下观察到负载组exosomes为直径50-100nm的膜性微囊,圆形或椭圆形,有完整包膜.FCM检测表明,负载组exosomes含有DC的特征分子(包括CD86、CD83).负载组来源的exosomes活化的T细胞对HepG2的杀伤率显著高于未负载组及单纯淋巴细胞组(P＜0.05).结论:肝癌细胞裂解物负载能增强DC分泌的exosomes体外诱导CTL效应.本研究为制备高效的exosomes肝癌瘤苗提供了实验依据.%Objective:To obtain high eifficacy hepatocellular carcinoma exosomes cancer vaccine and to assess the properties of these exosomes.Methods:Dendritic cells (DCs) were induced with cytokines and then loaded with whole hepatocellular carcinoma cell lysates.Exosomes were isolated from supematant of DCs.Transmission electron microscopy was used to observe their structu1es.The expressions of several proteins were investigated by flow cytometry.T lymphocytes were pulsed with exosomes directly in the presence of IL-2.After co-cultured with target cells,the stimulated lymphocytes were tested by cytotoxicity capacity assay.Results:Application of the isolation procedure to loaded DCs revealed exosomes vesicles by transmission electron microscopy.Protein analysis by FCM was performed and revealed that the costimulatory molecule CD86 and CD83 was detectable.The loaded DCs derived exosomes could directly activate T lymphocytes which lysed HepG2 target cells much more effectively than unloaded groups and L groups (P ＜ 0.05).Conclusion:The exosomes derived from loaded with whole hepatocellular carcinoma cell lysates could activate T cells directly and could induce effective HepG2 secific CTL responses.