造血干细胞来源的树突状细胞负载p53基因诱导对HMCC97肝癌细胞特异性杀伤

Dendritic cells derived from hematopoietic stem cells pulsed with p53 induce a specific immune response against HMCC97 hepatocellular carcinoma cells

目的:以p53基因转染CD34造血干细胞采集物来源的树突状细胞(dendritic cell,DC),诱导DC产生特异性抗肝癌免疫,观察其对表达P53抗原肝癌细胞的杀伤效果。方法:采用化疗和集落刺激因子联合动员肝癌患者外周血造血干细胞,血细胞分离机采集CD34+造血干细胞,白细胞介素(interleukin-4,IL-4)、粒-巨细胞集落刺激因子(granulocyte-macrophage colony-stimulating-factor,GM-CSF)联合肿瘤坏死因子(tumor necrosis factorα,TNF-α)刺激CD34+细胞分化为DC。通过脂质体转染的方法将携带人p53基因的质粒pEGFP-C3/p53转染培养7d的DC,MTT法检测对不同人肝癌细胞HMCC97和HepG2的特异性杀伤效果。结果:经细胞因子刺激诱导培养的DC具有典型的分枝状突起,高表达CD1a、CD11c、CD80、CD86和HLA-DR分子。转染p53基因后可见到转染DC细胞表达绿色荧光蛋白,免疫荧光染色可见转染p53基因的DC发出红色荧光,而未转染DC无荧光表达。MTT法检测结果表明,p53基因转染后的DC可诱发特异性细胞毒性T淋巴细胞(CTL)反应,杀伤表达P53抗原的HMCC97细胞,p53基因转染组、空载体组和未转染DC组的杀伤率分别为(49.3±4.6)%、(25.4±4.1)%和(24.8±3.8)%,转染组与空载体组和未转染DC组间存在统计学差异(P<0.05)。而对于不表达P53抗原的HepG2细胞,转染P53的DC诱导的CTL反应未能产生明显的杀伤作用,p53基因转染组、空载体组和未转染DC组的杀伤率分别为(30.8±4.6)%、(27.3±4.3)%和(28.5±5.1)%,3组间差异无统计学意义(P>0.05)。结论:p53基因转染CD34+造血干细胞来源的DC可诱导特异性CTL反应杀伤表达P53抗原的肝癌细胞,提示P53可能成为DC细胞免疫治疗的潜在靶点。

Objective：To evaluate dendritic cells induced immune response against hepatocellular carcinoma by pulsed CD34^＋ hematopoietic stem cells originated dendritic cells with p53 gene. Methods： CD34^＋ hematopoietie stem cells were harvested after mobilization by chemotherapy and G-CSF. CD34^＋ hematopoietie stem cell apheresis was induced to differentiate into dendritic cells by cytokine cocktail IL-4, GM-CSF and TNF-α. On day 7, dendritic cells were transfected with plasmid pEGFP-C3/p53 DNA. The CTL response triggered by p53 pulsed dendritic cells was assayed by MTT method. Results ： Dendritic cells originated from CD34^＋ cell apheresis had typical dendritic stick and expressed high level CD1a, CDllc, CD80, CD86, and HLA-DR molecules. After being pulsed with p53 gene, dendritic cells expressed green fluorescence protein and immunofluorescence assay （Cy3 labeled anti-P53 antibody） showed that transfected dendritic cells emitted red fluorescence. Dendritic cells inducing CTL response against HMCC97 cells （P53 positive） and HepG2 cells （P53 negative） were assessed by MTT method. P53 pulsed dendritic cells could induce P53 specific immune response against HMCC97 cells and the eytotoxin rate was （49.3±4.6） % compared with pEGFP-C3 transfeetion group [（25.4±4.1）%] and control group[（24.8±3.8）%]（P〈0.05）. However, P53 pulsed dendritic cells could not induce specific CTL against 1753 expression negative HepG2 cells, which the cytotoxin rates were （30.8±4.6）% , （27.3±4.3） %, and （28.5 ±5.1） % respectively in pEGFP-C3/P53 transfection group, pEGFP-C3 transfection group and control group （P〉0.05）. Conclusion ： P53 gene transfecting hematopoietic stem cell apheresis originated dendritic cells could induce specific CTL response against P53-expressing hepatocellular carcinoma cells. P53 may be a potential candidate for dendritic cell based immunotherapy of cancer.