Data Sheet 1_PLGA nanoparticles as an efficient carrier in Toxoplasma GAP45: a more effective vaccine against acute toxoplasmosis than traditional ones.docx

IntroductionToxoplasma gondii (T. gondii), as a strict intracellular parasite, can infect nearly all mammals, including humans, posing significant threats to public health. Toxoplasmosis in animals also leads to substantial economic losses in animal husbandry. Currently, no effective treatments are available for toxoplasmosis, creating an urgent need for safe and efficient therapeutics.
MethodsIn this study, we constructed a subunit vaccine using T. gondii glidesome-associated protein 45 (TgGAP45). To enhance immunogenicity, poly (lactic-co-glycolic acid) (PLGA) nanoparticles were employed as delivery carriers to prepare TgGAP45-PLGA nanospheres. For comparison, two oil adjuvants, Montanide™ ISA 660 VG and Montanide™ ISA 206 VG, were used to formulate TgGAP45-206VG and TgGAP45-660VG emulsions. Following safety evaluation, protective immunity was assessed in animals. Antibody levels, cytokine profiles, dendritic cell (DC) maturation and differentiation, and T lymphocyte proliferation and differentiation were analyzed.
ResultsThe results demonstrated that TgGAP45-PLGA nanospheres induced a mixed Th1/Th2 immune response against T. gondii. Furthermore, parasite burden analysis in spleen and heart tissues revealed that TgGAP45-PLGA nanospheres provided the strongest immunoprotection among the tested vaccines.
DiscussionThese findings indicate that TgGAP45 delivered via PLGA nanospheres is a promising candidate for preventing acute toxoplasmosis. Further studies and applications are warranted to explore its full therapeutic potential.

引言
刚地弓形虫（Toxoplasma gondii, T. gondii）是一种专性胞内寄生虫，几乎可感染包括人类在内的所有哺乳动物，对公共卫生安全构成显著威胁。动物弓形虫病还会给畜牧业带来巨额经济损失。目前针对弓形虫病尚无有效治疗手段，因此亟需安全高效的防治制剂。

方法
本研究以刚地弓形虫滑行体相关蛋白45（TgGAP45）为靶标构建亚单位疫苗。为提升免疫原性，本研究采用聚乳酸-羟基乙酸共聚物（poly (lactic-co-glycolic acid), PLGA）纳米粒作为递送载体，制备TgGAP45-PLGA纳米球。为设置对照实验组，选用两种油佐剂Montanide™ ISA 660 VG与Montanide™ ISA 206 VG，分别配制得到TgGAP45-206VG与TgGAP45-660VG乳剂。完成安全性评价后，对实验动物的保护性免疫水平进行评估。检测指标涵盖抗体水平、细胞因子谱、树突状细胞（dendritic cell, DC）的成熟与分化情况，以及T淋巴细胞的增殖与分化状态。

结果
实验结果表明，TgGAP45-PLGA纳米球可诱导针对刚地弓形虫的混合型Th1/Th2免疫应答。此外，对脾脏与心脏组织的寄生虫负荷分析显示，在所有受试疫苗中，TgGAP45-PLGA纳米球的免疫保护效力最强。

讨论
本研究结果证实，经PLGA纳米球递送的TgGAP45是一种极具潜力的急性弓形虫病预防候选制剂。后续仍需开展进一步研究与应用，以充分挖掘其治疗潜力。