Gong Pengtao, Cao Lili, Guo Yanbing, Dong Hang, Yuan Shuxian, Yao Xinhua, Ren Wenzhi, Yao Lin, Xu Zhilin, Sun Qiang, Zhang Xichen
College of Animal Sciences and Veterinary Medicine, Jilin University, Changchun, Jilin Province 130062, PR China.
Jilin Academy of Animal Husbandry and Veterinary Medicine, Changchun, Jilin Province 130062, PR China.
Exp Parasitol. 2016 Jul;166:131-6. doi: 10.1016/j.exppara.2016.04.003. Epub 2016 Apr 6.
The intracellular parasite Toxoplasma gondii is a major cause of abortion and neonatal loss in livestock, and can cause severe illness to human with weakened immune system. The heavy incidence and severe consequence indicate the development of vaccines against T. gondii is required. In this study, DNA vaccines encoding GRA1 and MIC3 antigens were developed. The parasite-specific immune responses and protection efficiency against toxoplasmosis by these DNA vaccines were evaluated in BALB/c mice. The results demonstrated that the IgG antibody production was significantly increased in multi-antigenic vaccine encoding GRA1 and MIC3 immunized group, as well as the IFN-γ level, when compared with single-gene vaccines and controls groups (p < 0.05). Two weeks after the final vaccination, the mice were challenged with either 1 × 10(4) or 1 × 10(2) RH strain tachyzoites, and the mortality and parasite reduction were observed. The multi-antigenic vaccine encoding GRA1 and MIC3 lead to the longest survival time as well as the less parasite-loads in brain and liver of immunized mice (p < 0.01). The present study indicates that the GRA1 and MIC3 showed the potential as target for vaccine investigation against toxoplasmosis. And the immune efficacy induced by multi-antigenic vaccine encoding GRA1 and MIC3 was better than that induced by single-antigenic vaccines alone.
细胞内寄生虫刚地弓形虫是家畜流产和新生儿死亡的主要原因，并且可导致免疫系统较弱的人患重病。高发病率和严重后果表明需要研发针对刚地弓形虫的疫苗。在本研究中，开发了编码GRA1和MIC3抗原的DNA疫苗。在BALB/c小鼠中评估了这些DNA疫苗针对弓形虫病的寄生虫特异性免疫反应和保护效率。结果表明，与单基因疫苗组和对照组相比，编码GRA1和MIC3的多抗原疫苗免疫组的IgG抗体产生显著增加，以及IFN-γ水平也显著增加（p<0.05）。最后一次接种疫苗两周后，用1×10⁴或1×10²速殖子RH株攻击小鼠，并观察死亡率和寄生虫减少情况。编码GRA1和MIC3的多抗原疫苗使免疫小鼠的存活时间最长，并且脑和肝脏中的寄生虫载量最少（p<0.01）。本研究表明，GRA1和MIC3显示出作为抗弓形虫病疫苗研究靶点的潜力。并且编码GRA1和MIC3的多抗原疫苗诱导的免疫效果优于单独的单抗原疫苗诱导的免疫效果。
