Bian Shu, Cai Qingxiu, Wang Shujing, Xie Ying, Chen Nianyuan, Song Qingyang, Li Hongmei, Zhao Ningning, Zhang Xiao
Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Tai'an, China.
The National Animal Health Products for Engineering Technology Research Center.
Vaccine. 2025 Jan 25;45:126632. doi: 10.1016/j.vaccine.2024.126632. Epub 2024 Dec 19.
Toxoplasmosis is a significant zoonotic disease that poses a serious threat to both human and animal health. Despite ongoing research, developing an effective vaccine for toxoplasmosis remains a challenge. In this study, we evaluated the vaccine potential of the Toxoplasma Urm1 gene deletion mutant (PruΔUrm1) by assessing its pathogenicity and protective efficacy in mice. Using CRISPR/Cas9 technology, we successfully created a type II Toxoplasma gondii Pru mutant strain with a deleted Urm1 gene. Compared to the wild-type parasite, the PruΔUrm1 strain exhibited significantly reduced invasive and proliferative abilities in vitro. In in vivo studies, mice intraperitoneally infected with the parental Pru strain showed severe symptoms including emaciation, hunching, and high mortality rates. In contrast, mice infected with PruΔUrm1 tachyzoites demonstrated a 100 % survival rate, no overt symptoms, and a markedly reduced parasite burden in the liver, spleen, and lungs, indicating reduced pathogenicity. Notably, PruΔUrm1 vaccination triggered a strong immune response, characterized by significantly elevated cytokine levels, including TNF-α, IFN-γ and IL-10. Furthermore, we assessed the immunoprotective efficacy of PruΔUrm1 vaccination in mice against type I strains. Mice immunized with PruΔUrm1 were able to resist the tachyzoites of type I RH wild-type parasites, achieving a 100 % survival rate and significantly reduced parasite loads in the liver, spleen and lungs. These data demonstrate that PruΔUrm1 immunization provides effective protection against acute Toxoplasma infections and holds promise as a potential vaccine candidate for toxoplasmosis.
弓形虫病是一种重要的人畜共患病，对人类和动物健康构成严重威胁。尽管研究仍在进行，但开发一种有效的弓形虫病疫苗仍然是一项挑战。在本研究中，我们通过评估弓形虫Urm1基因缺失突变体（PruΔUrm1）在小鼠中的致病性和保护效力，来评估其疫苗潜力。利用CRISPR/Cas9技术，我们成功创建了一种缺失Urm1基因的II型刚地弓形虫Pru突变株。与野生型寄生虫相比，PruΔUrm1株在体外的侵袭和增殖能力显著降低。在体内研究中，腹腔感染亲本Pru株的小鼠表现出严重症状，包括消瘦、弓背和高死亡率。相比之下，感染PruΔUrm1速殖子的小鼠存活率为100%，无明显症状，肝脏、脾脏和肺部的寄生虫负荷显著降低，表明致病性降低。值得注意的是，PruΔUrm1疫苗接种引发了强烈的免疫反应，其特征是细胞因子水平显著升高，包括TNF-α、IFN-γ和IL-10。此外，我们评估了PruΔUrm1疫苗接种对小鼠抵抗I型菌株的免疫保护效力。用PruΔUrm1免疫的小鼠能够抵抗I型RH野生型寄生虫的速殖子，存活率达到100%，肝脏、脾脏和肺部的寄生虫负荷显著降低。这些数据表明，PruΔUrm1免疫接种可有效预防急性弓形虫感染，有望成为弓形虫病的潜在疫苗候选物。
