重组SEA基因真核表达载体的构建及诱导小鼠抗肝癌免疫的效应

目的：构建葡萄球菌肠毒素A（SEA）真核表达载体，并通过体内转染，观察其诱导抗小鼠肝癌的免疫效应。方法：采用基因工程技术构建SEA基因的真核表达载体，使其表达SEA分子。通过阳离子脂质体介导的体内转染，观察其对小鼠肝癌的治疗作用。用^51Cr释放法测定治疗组与对照组动物脾淋巴细胞杀伤H22细胞的活性。结果：成功地构建了SEA真核表达载体pLXSN-SEA,体内转染pLXSN-SEA的荷瘤小鼠肿瘤明显缩小，生存期延长，4／10小鼠肿瘤完全消退，且长期无瘤生存。CTL杀伤活性实验表明，瘤区内转染pLXSN-SEA可诱导强烈的CTL杀伤效应，与对照组相比较差异显著（P＜0．01）。结论：超抗原SEA体内转染对肿瘤具有明显的治疗作用，有望用于抗肿瘤的生物治疗。

Construction of recombinant SEA gene eukaryotic expression vectors and its induction of immune response against murine hepatoma

AIM To construct recombinant SEA gene eukaryotic expression vectors and observe its immunological effects in vivo against murine hepatoma. Methods Gene recombination techniques were used to construct eukaryotic expression vectors containing SEA genes. After in vivo transfection of pLXSN-SEA mediated by liposome mediation, therapeutic effects of pLXSN-SEA were observed. Results pLXSN-SEA had been constructed successfully. After in vivo transfection of pLXSN-SEA, the tumor size volume in mice bearing hepatoma mould reduce obviously, of them, tumors of 4 in 10 mice disappeared completely and survival period of the mice also lengthened. Cytotoxic assay showed that the SEA expression could induce activation of mouse splenic lymphocytes and made tumor cells easily killed. Conclusion SAg SEA possesses strong anti-tumor activity. It is a hopeful candidate for biological therapy of tumors.