Institute of Military Veterinary, Academy of Military Medical Sciences, Changchun 130062, Jilin Province, China.
Res Vet Sci. 2010 Aug;89(1):93-7. doi: 10.1016/j.rvsc.2010.01.007. Epub 2010 Feb 4.
More effective vaccines against Toxoplasma gondii may contribute to the control of this pathogen that has major veterinary and public health significance. In this study, two recombinant plasmids pcDNA/TgSAG1 and pVAX/mIL-18 containing T. gondii SAG1 (TgSAG1) and murine cytokine interleukin-18 (IL-18) were evaluated for their ability to protect mice against T. gondii challenge. Mice were given two intramuscular immunizations 3 weeks apart, and challenged with T. gondii 3 weeks later. All animals vaccinated with pcDNA/TgSAG1 alone or with pVAX/mIL-18 developed specific anti-TLA (T. gondii lysate antigen) antibodies and specific lymphocyte proliferative responses. Co-injection of pVAX/mIL-18 significantly increased the production of IFN-gamma and IL-2. Further, challenge experiments showed that co-immunization with pVAX/mIL-18 significantly (P<0.05) increased the survival rate (60%), compared with pcDNA/TgSAG1 alone (40%). Therefore, codelivery of the IL-18-secreting plasmid potentiates the induction and maintenance of the type 1 helper T-cell immune response and may be a potent strategy for enhancing the protective efficacy of vaccines against T. gondii.
更有效的弓形虫疫苗可能有助于控制这种具有重要兽医和公共卫生意义的病原体。在这项研究中，评估了含有弓形虫 SAG1（TgSAG1）和鼠细胞因子白细胞介素 18（IL-18）的两个重组质粒 pcDNA/TgSAG1 和 pVAX/mIL-18，以确定它们预防弓形虫感染的能力。小鼠接受两次肌肉内免疫，间隔 3 周，然后在 3 周后用弓形虫进行挑战。单独用 pcDNA/TgSAG1 或用 pVAX/mIL-18 接种的所有动物均产生针对 TLA（弓形虫裂解抗原）的特异性抗体和特异性淋巴细胞增殖反应。共注射 pVAX/mIL-18 显着增加了 IFN-γ和 IL-2 的产生。此外，挑战实验表明，与单独用 pcDNA/TgSAG1 相比（40％），与 pVAX/mIL-18 共同免疫显着（P<0.05）提高了存活率（60％）。因此，IL-18 分泌质粒的共递送增强了 1 型辅助 T 细胞免疫反应的诱导和维持，并且可能是增强针对弓形虫的疫苗的保护效力的有效策略。
