Abstract：
Toxoplasma gondii (T. gondii) is one of the most common pathogenic protozoa in the world, and causes toxoplasmosis, which in varying degrees causes significant economic losses and poses a serious public health challenge globally. To date, the development of an effective vaccine for human toxoplasmosis remains a challenge. Given that T.gondii calcium-dependent protein kinase 3 (CDPK3), dense granule protein 35 (GRA35) and rhoptry organelle protein 46 (ROP46) play key roles during Toxoplasma gondii invasion of host cells, we developed a protein vaccine cocktail including these proteins and validated its protective efficacy. The specific protective effects of vaccine on mice were analyzed by measuring serum antibodies, cytokines, splenocyte proliferation, the percentage of CD4+ and CD8+ T-lymphocytes, survival rate, and parasite cyst burden. The results showed that mice vaccinated with a three-protein cocktail produced the highest levels of immune protein antibodies to IgG, and high levels of IFN-γ, IL-2, IL-4, and IL-10 compared to other mice vaccinated with two proteins. In addition, CD4+ and CD8+ T cell percentages were significantly elevated. Compared to the control groups, mice vaccinated with the three-protein cocktail survived significantly longer after acute infection with T. gondii and had significantly fewer cysts after chronic infection. These results demonstrated that a cocktail vaccine of TgCDPK3, TgGRA35, and TgROP46 can effectively induce cellular and humoral immune responses with good protective effects in mice, indicating its potential as vaccine candidates for toxoplasmosis.
摘要：
弓形虫(T.gondii)是世界上最常见的病原原生动物之一，并导致弓形虫病，这在不同程度上造成了巨大的经济损失，并在全球范围内构成了严重的公共卫生挑战。迄今为止,开发有效的人类弓形虫病疫苗仍然是一个挑战。鉴于弓形虫钙依赖性蛋白激酶3（CDPK3），致密颗粒蛋白35(GRA35)和右旋细胞器蛋白46(ROP46)在弓形虫入侵宿主细胞过程中发挥关键作用,我们开发了一种包含这些蛋白质的蛋白质疫苗混合物，并验证了其保护功效。通过检测血清抗体,分析疫苗对小鼠的特异性保护作用,细胞因子,脾细胞增殖，CD4+和CD8+T淋巴细胞的百分比，存活率,和寄生虫囊肿负担。结果表明，接种三种蛋白混合物的小鼠产生的免疫蛋白抗体水平最高，和高水平的IFN-γ，IL-2、IL-4和IL-10与接种两种蛋白质的其他小鼠相比。此外,CD4+和CD8+T细胞百分比显著升高。与对照组相比，接种三蛋白混合物的小鼠在弓形虫急性感染后存活时间明显更长，慢性感染后囊肿明显减少。这些结果表明，TgCDPK3，TgGRA35和TgROP46的鸡尾酒疫苗可以有效诱导小鼠的细胞和体液免疫反应，具有良好的保护作用。表明其作为弓形虫病候选疫苗的潜力。
