日本血吸虫复合DNA疫苗的组织表达及免疫保护效果研究

目的 :观察本课题组所构建日本血吸虫大陆株复合DNA疫苗VR10 12 SjGST和VR10 12 SjGST Sj32在小鼠肌肉组织中的表达 ,并进行免疫保护效果测定。方法 :用纯化质粒免疫昆明鼠 :4 8只小鼠分为 4组 ,两个对照组的小鼠分别于股四头肌注射生理盐水 10 0 μl或空质粒VR10 12 10 0 μg,两个实验组的小鼠则同法分别注射VR10 12 SjGST和VR10 12 SjGST Sj32各 10 0 μg。末次免疫后 ,每组解剖两只小鼠 ,以间接免疫荧光法观察SjGST、Sj32在肌肉组织中的表达。其余每只鼠经腹部感染 10条尾蚴 ,4 5d后剖杀计数各小鼠成虫数和肝卵数。结果 :小鼠肌肉组织表达出抗原特异性蛋白质抗原分子。与生理盐水组比较 ,两个实验组的减虫率分别为 33.9%和及 2 7.14 %(均为P <0 .0 5 ) ,减卵率分别为 6 1.86 %和 6 8.87% (均为P <0 .0 0 1)。与VR10 12 SjGST组相比 ,VR10 12 SjGST Sj32组的减卵率为 18.5 1% (P <0 .0 5 )。结论 :DNA疫苗VR10 12 SjGST和VR10 12 SjGST Sj32能在组织中正常表达 ,能诱导小鼠产生一定水平的抗日本血吸虫感染保护作用 ,复合疫苗的保护效果要大于单价疫苗

DNA Vaccines of VR1012-SjGST AND VR1012-SjGST-Sj32:Expression and Protective Immunity in Mice

Objective To observe the gene expression and the protective immunity induced by the DNA vaccines of VR1012-SjGST and VR1012-SjGST-Sj32 of Schistosoma japonicum(Sj) in mice. Methods Forty-eight mice were divided into four groups. Each mouse of control groups was injected in quadriceps femoris with NS or VR1012; for the test groups, with VR1012-SjGST and VR1012-SjGST-Sj32. Two mice from every group were dissected and the expression product of the DNA vaccine was detected by indirect immunofluorescence assay. Other mice were challenged each with 10 cercariae of S. joponicum at 30 days after final immunization. At day 45 after challenge, all mice were sacrificed, the numbers of worms and hepatic eggs were counted. Results The specific positive reaction of the indirect immunofluorescence assay was observed in muscle tissue. Compared with the NS control group, the worm reduction in 2 test groups was 33.9% and 27.14%(P<0.05); while the egg reduction was 61.86% and 68.87%(P<0.001) respectively. Compared with the VR1012-SjGST group, the egg reduction in VR1012-SjGST-Sj32 group was 18.51%(P<0.05). Conclusion The DNA vaccines, VR1012-SjGST and VR1012-SjGST-Sj32, could be expressed in the muscle tissue of the mouse and could induce partial protective immunity against S. joponicum in mice. The Protective Immunity induced by multivalent DNA vaccine was better than that induced by monovalent DNA vaccine.