Institute of Animal Husbandry and Veterinary Medicine, Department of Animal Parasitology, Zhejiang Academy of Agricultural Sciences, Hangzhou, China.
Institute of Animal Science and Technology, Department of Animal Diseases Diagnosis and Control of Xinjiang Production & Construction Corps, Tarim University, Alar, China.
Front Cell Infect Microbiol. 2023 Jul 12;13:1209755. doi: 10.3389/fcimb.2023.1209755. eCollection 2023.
Toxoplasma gondii is an apicomplexan parasite that affects the health of humans and livestock, and an effective vaccine is urgently required. Nanoparticles can modulate and improve cellular and humoral immune responses.
In the current study, poly (D, L-lactic-co-glycolic acid) (PLGA) nanoparticles were used as a delivery system for the T. gondii dense granule antigens GRA12 and GRA7. BALB/c mice were injected with the vaccines and protective efficacy was evaluated.
Mice immunized with PLGA+GRA12 exhibited significantly higher IgG, and a noticeable predominance of IgG2a over IgG1 was also observed. There was a 1.5-fold higher level of lymphocyte proliferation in PLGA+GRA12-injected mice compared to Alum+GRA12-immunized mice. Higher levels of IFN-g and IL-10 and a lower level of IL-4 were detected, indicating that Th1 and Th2 immune responses were induced but the predominant response was Th1. There were no significant differences between Alum+GRA7-immunized and PLGA+GRA7-immunized groups. Immunization with these four vaccines resulted in significantly reduced parasite loads, but they were lowest in PLGA+GRA12-immunized mice. The survival times of mice immunized with PLGA+GRA12 were also significantly longer than those of mice in the other vaccinated groups.
The current study indicated that T. gondii GRA12 recombinant protein encapsulated in PLGA nanoparticles is a promising vaccine against acute toxoplasmosis, but PLGA is almost useless for enhancing the immune response induced by T. gondii GRA7 recombinant protein.
刚地弓形虫是一种顶复门寄生虫，影响人类和家畜的健康，因此急需有效的疫苗。纳米颗粒可以调节和增强细胞和体液免疫反应。
在本研究中，聚（D，L-乳酸-共-乙醇酸）（PLGA）纳米颗粒被用作弓形虫致密颗粒抗原 GRA12 和 GRA7 的递送系统。用这些疫苗对 BALB/c 小鼠进行免疫，并评估其保护效力。
用 PLGA+GRA12 免疫的小鼠表现出明显更高水平的 IgG，并且 IgG2a 相对于 IgG1 也明显占优势。与 Alum+GRA12 免疫的小鼠相比，PLGA+GRA12 注射的小鼠的淋巴细胞增殖水平高 1.5 倍。检测到更高水平的 IFN-g 和 IL-10，以及更低水平的 IL-4，表明诱导了 Th1 和 Th2 免疫反应，但主要的反应是 Th1。Alum+GRA7 免疫和 PLGA+GRA7 免疫组之间没有显著差异。用这四种疫苗免疫导致寄生虫载量显著降低，但 PLGA+GRA12 免疫的小鼠最低。用 PLGA+GRA12 免疫的小鼠的存活时间也明显长于其他接种组的小鼠。
本研究表明，包封在 PLGA 纳米颗粒中的弓形虫 GRA12 重组蛋白是一种有前途的急性弓形虫病疫苗，但 PLGA 对增强弓形虫 GRA7 重组蛋白诱导的免疫反应几乎没有作用。
