目的：探讨分泌表达的抗ErbB2单链抗体与重构型人caspase-3融合蛋白对ErbB2抗原阳性肿瘤细胞的靶向杀伤作用。 方法：将重构型人caspase-3基因亚克隆入pCMV-e23scFv-PeⅡ-PEⅢ相应位点，构建表达分泌型的抗ErbB2单链抗体与重构型人caspase-3融合蛋白基因的真核表达载体pCMV-e23scFv-PeⅡ-revcasp-3，转染人T淋巴瘤细胞系Jurkat，筛选并建系，ELISA检测培养上清中融合蛋白的分泌表达。用含有该融合蛋白的培养介质培养人宫颈癌细胞Hela、乳腺癌细胞SKBr3以及人卵巢癌细胞SKOV3等研究该蛋白对细胞生长的抑制作用；将转染建系的Jurkat细胞尾静脉注射SKBr3荷瘤裸鼠研究其对肿瘤的抑制作用，间接免疫荧光检测重构型人caspase-3蛋白在瘤体的靶向分布。结果：融合蛋白基因可通过Jurkat细胞分泌表达并杀伤ErbB2抗原阳性的SKBr3和SKOV3细胞而对ErbB2抗原阴性的Hela细胞生长无明显影响，尾静脉注射该细胞可靶向抑制荷瘤裸鼠肿瘤生长。结论：分泌表达的抗ErbB2单链抗体与重构型人caspase 3融合蛋白靶向诱导ErbB2抗原阳性肿瘤细胞死亡。

Objiective：To investigate the targeted killing effect to ErbB2 antigen positive cells due to the expression of a secreted fusion protein consisting of anti-erB2 single chain antibody and reversed caspase-3 protein. Methods：pCMV-e23scFv-PeⅡ-revcasp-3 was constructed by sub cloning reversed caspase-3 gene to downstream of anti-erbB2 antibody and PE40 domain Ⅱ genes in recombinant pCMV vector and transfect Jurkat cells. The cell lines secreted expressing fusion protein stable were selected. Fusion protein in mediate was detected by ELISA. Then such mediate was used to culture Hela, SKBr3 and SKOV3 cells respectively and their survivals were compared through MTT. Finally Jurkat- pCMV-e23scFv-PEⅡ-revcasp-3 cells were administrated to BALB/c nude mice bearing SKBr3 tumor through their tail veins. Results： Fusion protein could be expressed by Jurkat cells stably and kill SKBr3 and SKOV3 cells which express ErbB2 antigen but had no influence on Hela which does not expressed ErbB2 antigen. Administrating Jurkat- pCMV-e23scFv-PEⅡ-revcasp-3 cells could inhibit SKBr3 tumor in vivo. Conclusions: Secreted expression of the fusion protein consisting of anti-erbB2 antibody and reversed caspase-3 could targetedly induce ErbB2 antigen positive cells to death.

国家高技术研究发展计划（863计划）（2001AA217101）、国家杰出青年科学基金（399Z5036）及军队杰出中青年人研究基金（98J009）资助