中文摘要：

目的：建立稳定表达小鼠IL-12（mIL-12）的小鼠Lewis肺癌（Lewis lung carcinoma，LLC）细胞系LLC／mIL-12．为进一步研究mIL-12的免疫调节机制及其抗肿瘤作用奠定基础。方法：构建真核表达质粒pcDNA3．1（＋）-mIL-12，脂质体转染LLC细胞并测其表达。流式细胞仪（FCM）观察细胞周期和凋亡，G418筛选获得阳性克隆后大量培养并检测mIL-12活性。结果：pcDNA3．1（＋）-mIL-12质粒构建正确并成功转导入LLC细胞，重组质粒在mRNA及蛋白质水平均高表达mIL—12，mIL—12使LLC细胞周期重新分布，并促进其凋亡。LLC／mIL-12细胞培养上清能明显引起刀豆蛋白A（ConA）激活的小鼠脾细胞增殖。结论：成功构建pcDNA3．1（＋）-mIL-12真核表达质粒，建立具有mIL—12生物学活性的LLC细胞系。

英文摘要：

Objective： To establish the murine Lewis lung carcinoma cell （LLC） line which can express the murine IL-12 gene stahly and to provide a basis for further study of its immunoregulatory mechanism and antitumor immune response, Methods： The recombinant plasmid containing the mIL-12 gene was transfected by lipofeetion into the LLC cell line, and its expression in LLC cells was measured. Cell cycle and apoptosis were observed by FCM. The positive clone cells were obtained and euhured after selection with G418, and the activity of raiL-12 was examined. Results： PeDNA3.1 （＋）- mIL-12 plasmid was transfected into LLC cells successfully. RT-PCR and ELISA revealed that mIL- 12 showed high expression at the mRNA and protein levels and FCM revealed that the recombinant plasmid could promote LLC cell apoptosis. The T ceil proliferation experiment showed that the euhure supernatant of LLC/mIL-12 cells could induce proliferation of routine spleen cells activated by COMA. Conclusion： A pcDNA3.1 （＋）-mIL-12 eukaryotic expression plasmid has been constructed correctly and the mIL-12 in LLC cells has biological activity.