Aims

Toxoplasma gondii is an obligate intracellular, protozoan that causes a high incidence of serious zoonotic parasitic disease in humans. In the present study the immune-protective efficacy of a DNA vaccine encoding SAG1 in combination with a gene sequence encoding FliC of Salmonella typhimurium (Toll-like receptor 5 agonist) was evaluated against acute T. gondii infection in mice.

Methods and results

Ninety-nine female inbred BALB/c mice were divided into nine groups of 11 mice and were immunized intramuscularly three times at three-week intervals (days 0, 21 and 42) and challenged with virulent T. gondii RH strain 4 weeks later. The immunization of pVAX1-SAG1 administered with pVAX1-fliC in mice indicated specific humoral responses, with higher IgG antibody titers and a mixed IgG1/IgG2a response than in other groups (with a predominance of IgG2a over IgG2b and IgG1). Also, the cellular immune response elicited high levels of IFN-γ and IL-12 cytokines and low levels of IL-4 production compared to traditional adjuvants. Furthermore, the mice vaccinated with pVAX1-SAG1+pVAX1-fliC survived for slightly longer after the last immunization and challenge with the T. gondii.

Conclusion

This investigation indicated that cocktail DNA vaccine encoded SAG1 gene of T. gondii and FliC can protect against acute toxoplasmosis.

中文翻译：

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评价弓形虫表面抗原1（SAG1）和TLR-5配体作为BALB / c小鼠急性弓形虫病的遗传佐剂的DNA疫苗的免疫原性和保护作用。

目的

弓形虫是专性的细胞内原生动物，会引起人类严重的人畜共患寄生虫病高发。在本研究中，评估了编码SAG1的DNA疫苗与编码鼠伤寒沙门氏菌FliC的基因序列（Toll样受体5激动剂）的免疫保护功效，以对抗小鼠的弓形虫急性感染。

方法与结果

将99只雌性近交BALB / c小鼠分成9组，每组11只小鼠，并以三周的间隔（第0、21和42天）肌内免疫3次，并在4周后用强毒的弓形虫RH株攻击。在小鼠中对接种pVAX1-fliC的pVAX1-SAG1进行的免疫接种显示出特定的体液应答，与其他组相比，IgG抗体效价更高，IgG1 / IgG2a混合应答更高（IgG2a优于IgG2b和IgG1）。此外，与传统佐剂相比，细胞免疫反应引起高水平的IFN-γ和IL-12细胞因子和低水平的IL-4产生。此外，接种了pVAX1-SAG1 + pVAX1-fliC的小鼠在最后一次免疫和刚地弓形虫攻击后存活了更长的时间。

结论

该调查表明那鸡尾酒DNA疫苗编码的基因SAG1弓形虫和单腿可以抵御急性弓形虫病。