免疫刺激序列增强日本血吸虫DNA疫苗的免疫保护作用  

Enhancement of the Protective Effect of SjC23 DNA Vaccine againstSchistosoma japonicum Infection by Immunostimulatory Sequence

作　　者：赵松[1] 朱荫昌[1] D.A.Harn 司进[1] 任建功[1] 殷旭仁[1] 何伟[1] 梁幼生[1] 徐明[1] 许永良[1] 

机构地区：[1]江苏省血吸虫病防治研究所,江苏省寄生虫分子生物学重点实验室,无锡214064 [2]哈佛大学公共卫生学院

出　　处：《中国寄生虫学与寄生虫病杂志》2005年第1期1-5,共5页Chinese Journal of Parasitology and Parasitic Diseases

基　　金：联合国开发署 /世界银行 /世界卫生组织热带病研究与培训特别规划署 (TDR) (No .991 0 51 )~~

摘　　要：目的　探讨免疫刺激序列在日本血吸虫Mr 2 3 0 0 0膜蛋白 (SjC2 3 )DNA疫苗诱导BALB/c小鼠抗血吸虫感染中的作用。　方法　将SjC2 3基因片段克隆到增加了免疫刺激序列的真核表达质粒 pcDNA3 1 CpG中 ,构建pcDNA3 1 SjC2 3 /CpG。 40只雌性BALB/c小鼠随机分为 4组 ,① pcDNA3 1对照组 ;②pcDNA3 1 SjC2 3组 ;③ pcD NA3 1 CpG组 ;④ pcDNA3 1 SjC2 3 /CpG组。每鼠经两侧股四头肌注射质粒DNA共 10 0 μg ,隔 2周加强免疫 1次 ,共 3次。末次免疫后 4周经腹部皮肤感染日本血吸虫尾蚴 45条 /鼠 ,45d后计数成虫及肝脏虫卵数。首次免疫前和感染前 2d分别经尾静脉采血 ,检测IgG及IgG1、IgG2a。末次免疫后 3周取小鼠脾细胞 ,检测经伴刀豆球蛋白和SjC2 3重组蛋白刺激后小鼠白细胞介素 2 (IL 2 )、白细胞介素 4(IL 4)和γ干扰素 (IFN γ)。用51Cr释放法检测经SjC2 3重组蛋白刺激后脾细胞对小鼠淋巴瘤细胞的杀伤作用。　结果　②组和④组减虫率分别为 2 8 1%和 3 5 1% ,减卵率分别为 2 1 6%和 2 6 5 %。④组减虫率显著高于②组 (P <0 0 5 )。这两组均检测到特异性IgG ,IgG2a/IgG1比值分别为 10 1和 12 2。脾细胞经伴刀豆球蛋白和SjC2 3重组蛋白刺激后的IL 2水平 ,②组较①组、④组较③组均有升高。②组脾?Objective To investigate the effect of immunostimulatory sequence on SjC23 DNA vaccine against Schistosoma japonicum infection. Methods SjC23 gene fragment was inserted into pcDNA3 ^1-CpG to construct pcDNA3 ^1-SjC23/CpG. BALB/c mice in 4 groups were immunized intramuscularly 3 times at 2 week intervals, with 100 μg plasmid DNA per injection. Four weeks after the 3rd immunization, all mice were challenged with 45±1 cercariae of S.japonicum by abdominal skin penetration. After 45 days post-challenge, mice were perfused and the number of recovered worms and of eggs in liver was counted. Blood samples were collected from the tail vein of all mice 2 days before the 1st immunization and before challenge respectively. IgG, IgG1 and IgG2a in sera were detected. Three weeks after the 3rd inoculation, the spleen cells of 2 mice from each group were cultured and stimulated with ConA and recombinant peptide. The supernatant was collected to detect IL-2, IL-4 and IFN-γ. Simultaneously, the cytotoxic activity was detected with 51 Cr release assay in vitro. Results The worm reduction rate in SjC23 group and SjC23/CpG group was 28 ^1% and 35 ^1%, the hepatic egg reduction rate was 21 ^6% and 26 ^5%, respectively, compared with the control group. The level of protection in SjC23/CpG group was higher than that in SjC23 group (P<0 ^05). ELISA results indicated that mice immunized with pcDNA3 ^1-SjC23 and SjC23/CpG produced specific IgG to rSjC23, while mice immunized with pcDNA3 ^1 and pcDNA3 ^1-CpG did not. Mice in SjC23 group and SjC23/CpG group also produced IgG1 and IgG2a antibody isotypes, with the ratio of IgG2a/IgG1 10 ^1 and 12 ^2, respectively. In comparison with the control, the level of IL-2 and IFN-γ in mice immunized with pcDNA3 ^1-SjC23 and pcDNA3 ^1-SjC23/CpG was augmented. The cytotoxic activity of spleen cells from mice in SjC23/CpG group was augmented from 9 ^7% to 40 ^0% compared with that in SjC23 group. Conclusion The study indicates that immunostimulatory sequence appears to increase t

关 键 词：免疫刺激序列 PCDNA3 脾细胞 DNA疫苗 日本血吸虫 免疫保护作用 小鼠 白刺 刀豆 成虫 

分 类 号：R392[医药卫生—免疫学] R512[医药卫生—基础医学]