日本血吸虫调宁蛋白样蛋白P14基因疫苗对小鼠免疫保护作用研究

摘要

目的 研究日本血吸虫调宁蛋白样蛋白P14基因DNA疫苗对小鼠免疫保护作用.方法 制备无内毒素DNA疫苗,用于免疫小鼠.将雌性BALB/e小鼠随机分为4组,每组10只.生理盐水组给予100μL／鼠／次;空质粒组100 μg/鼠／次、pcDNA3.1 (+)-SjP14组、pcDNA3.1(+ )-SjP14+pcDNA3.1(+)-SjGST组分别给予100μg／鼠／次;每2w免疫一次,共3次.末次免疫后2w.经腹部皮肤感染日本血吸虫尾蚴(30±1)条／鼠.尾蚴攻击6周后解剖小鼠,收集成虫,计算减虫率;同时留取肝脏,部分消化后在显微镜下行虫卵计数,计算减卵率,部分肝脏用于组织病理学分析(HE染色法).观察肝细胞变化及肉芽肿情况.结果 与NS对照组比较,pcDNA3.1(+)-Sj P14p核酸疫苗组减虫率和减卵率分别达到44.6％和61.6％;sjP14核酸疫苗与SjGST核酸疫苗联合免疫组减虫率和减卵率分别提高至56.2％和73.5％.肝组织切片镜下显示,pcD-NA3.1(+)-SjP14组肝脏病变较生理盐水组和空质粒组明显减轻,pcDNA3.1(+)-SjP14+pcDNA3.1(+)-SjGST组肝脏损伤程度最轻,虫卵肉芽肿周围炎症反应轻,肉芽肿面积较小.结论 pcDNA3.1(+)-Sj P14核酸疫苗有一定程度的抗血吸虫感染作用,pcDNA3.1(+)-SjP14与pcDNA3.1 (+)-SjGST疫苗联合免疫能增强小鼠对血吸虫感染的保护.%The aim of this research was to study the immunoprotection of SjVU DNA vaccine against Schistosoma japonicum (S. japonicum) infection in mice. The endotoxin-free DNA vaccines were prepared for mice immunization. The BALB/c mice were randomly divided into 4 groups (n=10), which including saline control group, pcDNA3. 1( + ) group, pcDNA3. K + )-SjP14 group and pcDNA3. K + )-SjP14 + pcDNA3. l( + )-S>GST group. Except for those in control groups, all mice were immunized intramuscularly three times with a 2-week"s intervals. Mice in saline and pcDNA3. 1( + ) groups were given 100 jtg saline and pcDNA3.1(+) per mouse respectively. The pcDNA3. l( + )-5jP14 group was immunized with pcD-NA3. l( + )-SjP14 alone (100 jig/mouse ·time). And mice in the synergistic group were injected with pcDNA3. l( + )-S/P14 (100 jig/mouse · time) plus pcDNA3. l( + )-S^GST (100 fig/mouse · time). Two weeks after the last immunization, the cer-cariae of S. japonicum were infected to mice percutaneously (30+ 1 per mouse). Six weeks later, all mice were sacrificed by cervical dislocation. The adult worms were collected and the worm reduction rate was calculated as an index to evaluate the protective effect of DNA vaccines. Meanwhile, the liver was removed and some of them were digested and counted for the egg reduction rate. HE staining method was used to detect the hepatic changes and granuloma. After immunizing the mice, the results showed that DNA vaccine pcDNA3. l( + )-S)P14 enhanced the immune function of mice infected with cercariae of S. ja-ponicumi and the worm reduction rate and egg reduction rate reached to 44. 6% and 61. 6% , respectively. When combined withrnDNA vaccine pcDNA3. 1 ( + )-SjGST, the protective effect was significantly strengthened, and both worm and egg burdens were reduced markedly. The worm reduction rate and egg reduction rate reached to 56. 2% and 73. 5%, respectively. The structure of hepatic lobule was integrated togeth-er, and the inflammatory reaction around the egg granulomas was slight. It's suggested that the pcDNA3. l( + )-S/P14 DNA vaccine has some immunoprotection effect on S. japonicum infection, and the protective effect could be enhanced significantly by combining with pcDNA3. l( + )-SjGST DNA vaccine.