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

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

目的:观察CEA迷你基因串联体疫苗pcD NA-triC EA625-667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(pcD NA3.0)、单倍体疫苗实验组(pcD NACEA625-667)、串联体疫苗实验组(pcD NA-triC EA625-667),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pcD NA-triC EA+625-667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pcD NA-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。

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 pc DNA-tri CEA625-667 and to evaluate the safety of the vaccine. Methods： The BALB / c mice were randomly divided into blank vector group（ pc DNA3. 0）,haploid vaccine group（ pc DNA-CEA625-667） and tandem repeats vaccine group（ pc DNA-tri CEA625-667）. 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 Pc DNA3. 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 pc DNA-tri CEA625-667 was stronger than that induced by pc DNA-tri CEA625-667（ 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.