CEA 迷你基因串联体疫苗免疫小鼠脾细胞对CEA 阳性肿瘤细胞的杀伤作用及疫苗的安全性评价

目的:观察CEA 迷你基因串联体疫苗pcDNA-triCEA625-667 免疫小鼠脾细胞对肿瘤细胞特异性杀伤作用并对疫苗免疫小鼠后的安全性进行评估。方法: BALB/ c 小鼠随机分为空白载体组(pcDNA3.0)、单倍体疫苗实验组(pcDNA-CEA625-667 )、串联体疫苗实验组(pcDNA-triCEA625-667 ),肌肉注射法免疫动物,每隔10 d 免疫1 次,共免疫4 次,记录免疫小鼠的体重变化、存活情况以及检测血清ALT、肌酐水平。以疫苗免疫小鼠的脾细胞为效应细胞,以LDH 释放法检测其对CEA 阳性的小鼠肝癌细胞株(H22-CEA+ )、胃癌细胞株(MFC-CEA+ )、结肠癌细胞株(CT26-CEA+ )以及CEA 阴性小鼠肝癌细胞株(H22-CEA- )的特异性CTL 的杀伤活性。结果:两种疫苗对CEA 阳性的肝癌、胃癌及结肠癌细胞均具有较强的杀伤活性,与PcDNA3.0 空载体组相比,差异有统计学意义(P<0.01)。而对CEA 阴性肿瘤细胞(H22-CEA- )则几乎无影响。迷你串联体基因疫苗pcDNA-triCEA625-667 对肝癌细胞H22-CEA+及胃癌细胞MFC-CEA+的杀伤活性强于单倍体基因疫苗pcDNA-CEA625-667(P<0.05)。疫苗免疫对小鼠的存活状态、体重变化及肝肾功能指标均无影响。结论:CEA 迷你基因疫苗安全有效,能够诱导肿瘤特异性CTL 产生,且三倍体串联体疫苗免疫效果优于单倍体疫苗。

Tumor specific immune response induced by three tandem repeats of CEA mini gene DNA vaccine and safety evaluation

Objective:To observe the specific killing effect on tumor cells of the spleen cells in mice immunized with three tandem repeats of CEA minigene DNA vaccine pcDNA- triCEA625-667 and to evaluate the safety of the vaccine.Methods: The BALB/ c mice were randomly divided into blank vector group (pcDNA3.0),haploid vaccine group (pcDNA-CEA625-667 ) and tandem repeats vaccine group (pcDNA-triCEA625-667 ).The mice received a total of 4 intramuscular immunization every 10 days once.The changes of body weight,survival state were recorded and the levels of serum ALT and serum creatinine were detected.The specific CTL killing activity of spleen cells in accinated mice on mouse hepatoma cells(H22-CEA+ ),gastric cancer cells(MFC-CEA+ ),colorectal cancer cells( CT26-CEA+ ) with high expression of CEA and mouse hepatoma cells ( H22-CEA- ) without expression of CEA was detected.Results: The two vaccines had strong killing activity on CEA positive liver cancer,gastric cancer and colon cancer cells,and the difference was statistically significant (P <0.01) compared with the PcDNA3.0 group.And they had almost no effect on CEA negative tumor cells (H22-CEA- ).The killing activity on liver cancer cell(H22-CEA+ ) and gastric cancer cell(MFC-CEA+ ) induced by pcDNA-triCEA625-667 was stronger than that induced by pcDNA-triCEA625-667(P<0.05).The survival status,change of body weight and function of liver and kidney of the mice were not affected by the vaccine.Conclusion: There was no adverse reaction in the course of vaccine immunization.The minigene DNA vaccine derived from CEA can induce tumor specific CTL effect and the immune response level elicited by three tandem repeats of minigene DNA vaccine was superior to that elicited by haploid vaccine.