Objective To investigate the anti-tumor immune response induced by human pancreatic cancer mucin 4 mRNA and human telomerase reverse transcriptase (hTERT) mRNA cotransfected dendritic cells (DC),and to provide the experimental evidences for the treatment of pancreatic cancer with multi-epitope loaded DC vaccine.Methods DC were isolated from peripheral blood mononuclear cells (PBMC) of six patients with HLA-A2+ pancreatic cancer and cultured.Mucin 4 mRNA and hTERT mRNA were transcripted and amplified in vitro,which were transfected into DC separately or in order by eleetroporation.DC were cultured for 48 hours.The expressions of mucin 4 and hTERT in DC were detected by quantitative real-time polymerase chain reaction (PCR) and Western blot.The survival rates of transfected DC were determined by methylthiazolyl tetrazolium (MTT) method.The cytotoxic T lymphocyte (CTL) activation induced by mucin 4 mRNA and hTERT mRNA transfected DC were evaluated by interferon (IFN)-γ release assays (enzyme linked immunosorbent assay) method.The cytotoxicity of CTL induced by mucin 4 mRNA and hTERT mRNA transfected DC in pancreatic cancer cell lines MiaPaCa-2,Capan-2,AsPC-1 and Pane-1 was measured by 51Cr standard cytotoxicity test.Student t test was performed for statistical analysis.Results After in order transfection of mucin 4 mRNA and hTERT mRNA for 48 h,the relative quantity of the expression of mucin 4 and hTERT in DC were 30.09±5.24 and 12.87±3.36,which were lower than the relative quantity of the expression in DC transfected separately (38.54±6.21 and 36.35±5.03,t=3.469,6.721,both P＜0.05).After transfected in order for 96 hours,the survival rate of DC decreased to 52.17％,which was lower than that of DC transfected separately (around 80％).The quantity of IFN-γ releasing of specific CTL induced by mucin 4 mRNA and hTERT mRNA cotransfected DC was (32.57±2.01) U/mL in 24 hours,which was higher than that of CTL induced by DC transfected with mucin 4 mRNA ((23.06±4.74) U/mL) or hTERT mRNA ((16.82±3.67) U/mL) separately (1=5.092,7.141,both P＜0.05).After co-transfected with mucin4 mRNA and hTERT mRNA,DC could effectivly induce HLA-A2+/mucin 4+/hTERT+ specific CTL immune responses,however there was no significant cytotoxicity in HLA-A2+ pancreatic cancer cells.Conclusion The induction of CTL anti-tumor immune response by DC co-transfected with mucin4 mRNA and hTERT mRNA is more significant compared with that by single antigen loaded DC.%目的 研究人胰腺癌黏蛋白4 mRNA与人端粒酶反转录酶(hTERT) mRNA联合转染树突状细胞(DC)诱导的抗肿瘤免疫反应,为构建负载多抗原表位DC疫苗治疗胰腺癌提供实验依据.方法 自6例HLA-A2+的胰腺癌患者外周血单个核细胞中分离、培养DC.体外转录和扩增黏蛋白4和hTERT mRNA,电穿孔法将两者分别及联合转染DC,培养48 h.采用实时定量PCR和Western印迹技术检测DC中黏蛋白4和hTERT的表达.用MTT法监测转染前后DC存活率；使用IFN-γ释放试验(ELISA法)检测黏蛋白4 mRNA和(或)hTERT mRNA转染后DC诱导的CTL的活化反应.采用51Cr标准细胞毒实验检测转染黏蛋白4 mRNA和(或)hTERT mRNA后DC诱导的CTL对体外胰腺癌细胞株MiaPaCa-2、Capan-2、AsPC-1和Panc-1细胞的杀伤作用.采用studentt检验进行统计学处理.结果 黏蛋白4 mRNA与hTERT mRNA联合转染后48 h DC中两者的相对表达量分别为30.09±5.24和12.87±3.36,低于其分别转染时的相对表达量(38.54土6.21和36.35+5.03,t=3.469、6.721,P均＜0.05).黏蛋白4 mRNA与hTERT mRNA联合转染后96h DC存活率降至52.17％,低于分别转染时DC的存活率(均为80％左右).黏蛋白4和hTERT mRNA联合转染DC诱导的特异性CTL 24 h IFN-γ释放量达(32.57±2.01) U/mL,高于分别转染时DC诱导的CTL IFN-γ释放水平[(23.06±4.74) U/mL和(16.82±3.67) U/mL,t=5.092和7.1 11,P均＜0.05].DC经黏蛋白4 mRNA与hTERT mRNA联合转染后,可有效诱导HLA-A2-黏蛋白4+/hTERT+特异性CTL免疫反应,而对HLA-A2-的胰腺癌细胞无显著杀伤作用.结论 黏蛋白4 mRNA与hTERT mRNA联合转染的DC较单胰腺癌抗原负载DC诱导出更加显著的CTL抗肿瘤免疫.
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