弓形虫复合基因疫苗pcSAG1-ROP5诱导小鼠免疫应答的研究  

Immune Response in Mice Induced by Complex Gene Vaccine pcSAG1-ROP5 of Toxoplasma gondii

作　　者：赵焕阁[1] 范志刚[1] 黄风迎[1] 黄用豪[1] 周松林[1] 林映莹[1] 谭光宏[1] 

机构地区：[1]海南医学院海南省热带病重点实验室,海口571101

出　　处：《中国寄生虫学与寄生虫病杂志》2013年第1期1-5,共5页Chinese Journal of Parasitology and Parasitic Diseases

基　　金：海南省自然科学基金(No.809018)~~

摘　　要：目的观察弓形虫复合基因疫苗pcSAGl-ROP5免疫小鼠后诱导的免疫应答。方法构建弓形虫重组真核表达质粒pcSAGl、pcROP5和pcSAGl-ROP5，分别通过PCR、酶切和测序鉴定后，转染人宫颈癌细胞（HeLa细胞），蛋白印迹（Westernblotting）分析重组蛋白的体外表达情况。70只昆明小鼠随机均分为5组（每组14只），分别为pc-SAGl组、pcROP5组、pcSAGl-ROP5组、空质粒组和空白对照组。重组质粒组每次每只肌注100μg重组质粒，每2周免疫1次，共3次。空质粒组和空白对照组分别注射等量的空质粒和PBS。于每次免疫前和末次免疫后2周眼眶采血。制备血清。采用ELISA法检测pcSAGl-ROP5组小鼠末次免疫后2周的血清与重组蛋白SAGl、ROP5和SAGl-ROP5结合的效价，以及5组小鼠的各次血清中抗弓形虫抗体IgG水平。末次免疫后3周，每组小鼠取10只腹腔接种10s弓形虫速殖子，观察生存时间。末次免疫后4周，采用ELISA法检测小鼠脾细胞培养上清中r干扰素（IFN-r）和白细胞介素4（IL-4）的水平。结果重组真核表达质粒构建成功。Westernblotting分析结果显示，重组质粒pcSAGl、pcROP5和pcSAGl-ROP5均能在HeLa细胞中表达，重组蛋白的相对分子质量（尬）分别为31000、57000和88000。pcSAGl-ROP5组小鼠血清与重组蛋白SAGl、ROP5和SAGl-ROP5结合的效价分别为1：320、1：160和1：2560。3个重组质粒组小鼠血清抗弓形虫IgG抗体水平随着免疫次数的增加和时间的延长逐渐升高，末次免疫后2周，pcSAGl-ROP5组小鼠血清IgG抗体水平（0．612±0．031）显著高于其他各组（P〈0．05）。攻击感染后，pcSAGl-ROP5组小鼠的平均存活时间为（288±7）h，较pc—SAGl组和pcROP5组分别延长了48h和96h（P〈0．05）。末次免疫后4周，pcSAGl-ROP5组小鼠脾细胞培养上清中IFN-1水平[（908．52±6．31）pg／m1]显著高于其他各组（P〈0．05），各组的IL-4水平差异无统计学意义Objective To observe the immune response induced by complex gene vaccine pcSAG1-ROP5 of Toxoplasma gondii in mice. Methods The recombinant eukaryotic expression plasmids pcSAG1, pcROP5 and pcSAG1- ROP5 were constructed and identified by PCR, restriction enzyme digestion, and sequencing. The three recombinant plasmids were transfected into HeLa cells to express in vitro and identified by Western blotting analysis. Seventy Kunming mice were randomly divided into 5 groups with 14 each, i.e. pcSAG1 group, pcROP5 group, pcSAG1-ROP5 group, blank plasmid group and PBS control group. The mice were immunized intramuscularly with pcSAG1, pcROP5, pcSAG1-ROP5, pcDNA3.1, and PBS, respectively, every two weeks for three times. Sera were collected before each injection and 2 weeks after the last immunization. The titer of mice serum in pcSAG1-ROP5 group combined with recombinant protein SAG1, ROP5 and SAG1-ROP5 and the level of IgG against T. gondii in 5 groups were determined by ELISA. Three weeks after the last immunization, ten mice of each group were challenged with 103 tachyzoites of the virulent T. gondii RH strain to observe the survival time. One week later, the rest four mice in each group were sacrificed and the supernant of cultured splenocytes was collected for the detection of IFN-r and IL-4. ResultsWestern blotting showed that the recombinant plasmids pcSAG1, pcROP5 and pcSAG1-ROP5 were expressed in HeLa cells with Mr 31 000, 57 000, and 88 000, respectively. The serum titer in pcSAG1-ROP5 group combined with SAG1, ROP5 and SAG1-ROP5 was 1：320, 1：160, and 1：2 560, respectively. The IgG level kept rising in pcSAG1, pcROP5 and pcSAG1-ROP5 groups. Two weeks after the last immunization, the IgG level in pcSAG1-ROP5 group was higher than those in other groups（P〈0.05）. After a lethal challenge of T. gondii RH strain, the survival time of the mice in pcSAG1- ROP5 group was （288±7） h, which was 48 h and 96 h longer than the groups of pcSAG1 and pcROP5, respectively （P〈 0.05）. Four weeks after the la

关 键 词：刚地弓形虫 复合基因疫苗 SAG1-ROP5 

分 类 号：R382.5[医药卫生—医学寄生虫学]