摘要
【目的】弓形虫是一种专性细胞内寄生的原虫,可感染包括人类在内的所有温血动物。目前,弓形虫病的治疗缺乏特效药物,传统药物治疗存在毒副作用大、疗效有限等问题。因此,开发安全有效的疫苗成为防控该病的重要策略。弓形虫表面抗原相关序列蛋白(SRSs)在虫体的毒力、入侵与黏附、免疫调节等方面均发挥着关键作用。其中,SRS51蛋白(TGME49_308840)作为SRS家族成员之一,具体生物学功能尚不明确,具有潜在的研究价值。旨在探究弓形虫SRS51蛋白的生物学功能及作用机制,为开发安全有效的弓形虫疫苗提供参考依据。【方法】以弓形虫II型Pru株为研究对象,采用CRISPR-Cas9基因编辑和无缝克隆技术,构建Tgsrs51基因缺失株(PruΔsrs51),分别通过噬斑试验、细胞入侵与增殖试验、逸出试验、体外缓殖子转化试验以及小鼠毒力试验,系统评估弓形虫SRS51蛋白的生物学功能。【结果】Tgsrs51基因缺失后,弓形虫的噬斑面积和数量显著减少(P<0.000 1),降低了微线体蛋白MIC2的表达,入侵和胞内增殖能力明显下降(P<0.001),对小鼠的致病力也有所减弱(P<0.05),但不影响虫体的逸出能力和体外缓殖子转化(P>0.05)。【结论】SRS51蛋白缺失可显著削弱弓形虫的急性毒力及慢性包囊形成能力,可作为弓形虫弱毒疫苗候选基因。
[Objective]Toxoplasma gondii is an obligate intracellular protozoan parasite that infects all warm-blooded animals,including humans.Currently,there is a lack of specific drugs for the treatment of toxoplasmosis,and traditional drug therapy faces issues such as significant toxic side effects and limited efficacy.Therefore,developing a safe and effective vaccine has become an important strategy for preventing and controlling the disease.Surface antigen-related sequence proteins(SRSs)of T.gondii play a crucial role in virulence,invasion and adhesion,and immune regulation of the parasite.Among them,SRS51 protein(TGME49_308840),as a member of the SRS family,has potential research value due to its unclear specific biological function.This study aims to explore the biological function and mechanism of action of Toxoplasma gondii SRS51 protein,providing a reference for the development of safe and effective T.gondii vaccines.[Method]With the Toxoplasma gondii type II Pru strain as the subject,CRISPR-Cas9 gene editing and seamless cloning techniques were employed to construct a Tgsrs51 gene-deleted strain(PruΔsrs51).The biological function of the Toxoplasma SRS51 protein was systematically evaluated through plaque assay,cell invasion and proliferation assay,escape assay,in vitro bradyzoite conversion assay,and mouse virulence assay[.Result]After the deletion of the Tgsrs51 gene,the plaque area and number of T.gondii significantly decreased(P<0.0001).The deletion of the Tgsrs51 gene caused a decrease in MIC2 protein expression.The invasion and proliferation abilities were significantly reduced(P<0.001).The pathogenicity to mice also weakened(P<0.05),but it did not affect the escape ability and in vitro tachyzoite transformation of the parasite(P>0.05).[Conclusion]SRS51 protein deletion significantly reduces acute virulence and chronic cyst formation.It can be considered as a candidate gene for a weakened T.gondii vaccine.
作者
肖淑婷
江新成
王萌
邬向东
李谷月
陈小庆
XIAO Shuting;JIANG Xincheng;WANG Meng;WU Xiangdong;LI Guyue;CHEN Xiaoqing(Key Laboratory for Animal Health of Jiangxi Province,College of Animal Science and Technology,Jiangxi Agricultural University,Nanchang 330045,China;State Key Laboratory for Animal Disease Control and Prevention,Key Laboratory of Veterinary Parasitology of Gansu Province,Lanzhou Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Lanzhou 730046,China)
出处
《江西农业大学学报》
2026年第1期196-207,共12页
Acta Agriculturae Universitatis Jiangxiensis
基金
国家自然科学基金青年项目(32202839)
江西省科技计划青年项目(S2024QNJJL1431)。
