Department of Parasitology, Shandong University School of Medicine, Jinan, Shandong, PR China.
Vaccine. 2012 Feb 27;30(10):1800-6. doi: 10.1016/j.vaccine.2012.01.004. Epub 2012 Jan 10.
Previous immunological studies from our laboratory have demonstrated the potential role of Toxoplasma gondii antigens SAG1 and GRA2 as vaccine candidates. To further evaluate the vaccine's effects, a series of recombinant DNA vaccines pVAX1-SAG1, pVAX1-GRA2 and pVAX1-SAG1-GRA2, termed pSAG1, pGRA2 and pSAG1-GRA2, respectively, were constructed. A plasmid pVAX1-S/PreS2, termed pSPreS2 encoding hepatitis B virus (HBV) surface antigen (HBsAg) S and PreS2 as a novel genetic adjuvant, was also constructed. The expression abilities of those DNA plasmids were examined in HFF cells by Western blotting. Then BALB/c mice were intramuscularly immunized with DNA plasmids and followed by challenging with the highly virulent T. gondii RH strain. The results demonstrated that the recombinant DNA vaccine pSAG1-GRA2 was capable of eliciting high levels of antibodies, a Th1 type of immune response with significant production of IFN-γ and low levels of IL-4 or IL-10 in BALB/c mice, and partial protection against the acute phase of toxoplasmosis as compared to pSAG1, pGRA2 and controls. In addition, the adjuvant pSPreS2 formulated with DNA vaccine induced a Th1 type of immune response and therefore might be a novel genetic adjuvant to DNA vaccine for further investigation.
先前我们实验室的免疫研究表明，刚地弓形虫抗原 SAG1 和 GRA2 具有作为疫苗候选物的潜力。为了进一步评估疫苗的效果，构建了一系列重组 DNA 疫苗 pVAX1-SAG1、pVAX1-GRA2 和 pVAX1-SAG1-GRA2，分别命名为 pSAG1、pGRA2 和 pSAG1-GRA2。还构建了一个质粒 pVAX1-S/PreS2，称为 pSPreS2，其编码乙型肝炎病毒 (HBV) 表面抗原 (HBsAg) S 和 PreS2，作为一种新型遗传佐剂。通过 Western blot 检查了这些 DNA 质粒在 HFF 细胞中的表达能力。然后，用 DNA 质粒肌肉内免疫 BALB/c 小鼠，并用高毒力刚地弓形虫 RH 株进行攻毒。结果表明，与 pSAG1、pGRA2 和对照组相比，重组 DNA 疫苗 pSAG1-GRA2 能够在 BALB/c 小鼠中引起高水平的抗体，Th1 型免疫反应，显著产生 IFN-γ，IL-4 或 IL-10 水平较低，并对弓形虫病的急性阶段提供部分保护。此外，与 DNA 疫苗联合使用的佐剂 pSPreS2 诱导了 Th1 型免疫反应，因此可能是 DNA 疫苗的新型遗传佐剂，值得进一步研究。
