异种EGFR胞外区重组DNA疫苗与蛋白质疫苗抗小鼠Lewis肺癌的作用研究  

Anti-tumor effect of recombinant DNA and protein vaccine based on xenogeneic extracellular domain of EGFR on Lewis lung cancer in mice

作　　者：吴永[1] 张培德[1] 唐亮[2] 谈立松[2] 张尚权[3] 

机构地区：[1]复旦大学生命科学学院生物化学系,上海200433 [2]同济大学医学院附属上海市肺科医院肺癌免疫研究室,上海200433 [3]中国科学院上海生命科学研究院生物化学与细胞生物学研究所,上海200031

出　　处：《肿瘤》2009年第3期195-200,共6页Tumor

基　　金：上海市科学技术委员会科研计划资助项目(编号:05DZ19309)

摘　　要：目的:构建异种表皮生长因子受体(epidermal growth factor receptor,EGFR)胞外区重组DNA和蛋白质疫苗,观察其对小鼠Lewis肺癌的抗肿瘤作用。方法:克隆鸡源性EGFR胞外Ⅱ-Ⅲ区与IgG-Fc融合基因,构建重组DNA疫苗质粒pVAX1-cEGFR-Fc和原核表达质粒pET28a(+)-S-cEGFR-Fc,后者转化大肠杆菌,将诱导表达的重组蛋白作为蛋白质疫苗。免疫小鼠4次后接种Lewis肺癌细胞,19d后处死小鼠,剥离肿瘤称重并计算抑瘤率,检测小鼠血清中抗EGFR抗体效价,并检测特异性细胞毒性T淋巴细胞(cytotoxicity T lymphocyte,CTL)活性。结果:成功构建异种EGFR胞外区重组DNA和蛋白质疫苗。DNA疫苗组、蛋白质疫苗组和联合免疫组的抑瘤率分别为37%、49%和63%。3组小鼠均检测出抗EGFR抗体和CTL反应。结论:重组疫苗能打破机体对自身EGFR分子的免疫耐受,诱导特异性免疫反应,对小鼠Lewis肺癌有明显的抑制作用。2种疫苗的联合应用可进一步加强抑瘤作用。Objective：To construct a DNA vaccine and a protein vaccine based on xenogeneic extracellular domain （ECD） of epidermal growth factor receptor （EGFR） and to evaluate their anti-tumor effect on Lewis lung cancer in mice. Methods： This study cloned extracellular region Ⅱ-Ⅲ of EGFR of chicken origin and fused it with Fc portion of IgG gene to construct recombinant DNA vaccine plasmid pVAX1-cEGFR-Fc and prokaryotic expression plasmid pET28a（＋）-S-cEGFR-Fc. The plasmid pET28a（＋）-S-cEGFR-Fc was transformed into E.coli followed by induction with IPTG. The induced recombinant proteins were used as protein vaccine. Mice were challenged with Lewis lung cancer cells after four times immunization. The mice were sacrified after 19 d and the tumor weight was measured to calculate the inhibition rate of tumor growth. The sera from immunized mice were isolated for the detection of the levels of anti-EGFR antibodies. Spleen lymphocytes were isolated to determine the cytotoxic T lymphocyte（CTL） activity. Results： Both xeno-geneic DNA vaccine and protein vaccine were successfully constructed. The tumor inhibition rates of DNA vaccine group, protein vaccine group and combination immunization group were 37%, 49%, and 63%, separately. Anti-EGFR antibodies and CTL responses were induced in all the three vaccine groups. Conclusion：The recombinant DNA and protein vaccines can break the immune tolerance induced by self-EGFR molecules, induce specific anti-tumor immune responses, and markedly inhibit the growth of Lewis cancer in mice. The combined use of the two kinds of vaccines can further enhance the anti-tumor effect.

关 键 词：癌 Lewis肺 受体 表皮生长因子 癌症疫苗 免疫疗法 主动 

分 类 号：R73-362[医药卫生—肿瘤] R734.2[医药卫生—临床医学]