Toxoplasma gondii (T. gondii) is an obligate intracellular apicomplexan protozoan that can parasitize most warm-blooded animals and cause severe diseases in immunocompromised individuals or fetal abnormalities in pregnant woman. The treatment of toxoplamosis has been limited by effective drugs. Our previous work indicated that the novel gene wx2 of T. gondii may serve as a vaccine antigen candidate. To further investigate the molecular functions of wx2 in highly virulent T. gondii (RH strain), a wx2 gene deletion mutant RH strain (KO-wx2) was established using CRISPR-Cas9. The phynotype of KO-wx2 was analyzed by plaque, invasion, and replication assays in vitro as well as in vivo virulence assays. The results indicated that the targeted deletion of the wx2 gene significantly inhibited in vitro parasite growth and replication in the host cells as well as attenuated parasite virulence in the mouse model. Notably, the percentage of pro-inflammatory factors of interferon gamma (IFN-γ) and interlukin-17A (IL-17A) and anti-inflammatory factor of interlukin-10 (IL-10) in the lymph nodes were upregulated in mice infected with the KO-wx2 strain. Our data suggested that the wx2 gene plays an important role in the process of the parasite's life cycle and virulence in mice. In addition, it also plays an important role in the host's immunity reaction, mainly via Th1 and Th17 cellular immunity, not Th2.

中文翻译：

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弓形虫的新型wx2基因在体外抑制寄生虫侵袭和增殖，并通过免疫应答调节在体内减弱毒力。

弓形虫（T. gondii）是专性的细胞内apicomplexan原生动物，可以寄生大多数温血动物，并在免疫功能低下的个体中引起严重的疾病或孕妇的胎儿异常。弓形虫病的治疗受到有效药物的限制。我们以前的工作表明弓形虫的新基因wx2可以作为疫苗抗原候选物。为了进一步研究wx2在强毒弓形虫（RH株）中的分子功能，使用CRISPR-Cas9建立了wx2基因缺失突变体RH株（KO-wx2）。通过噬斑，侵袭和复制测定以及体外毒力测定分析了KO-wx2的植物型。结果表明，wx2基因的靶向缺失显着抑制了宿主细胞中体外寄生虫的生长和复制，并在小鼠模型中减弱了寄生虫的毒力。值得注意的是，在感染了小鼠的淋巴结中，干扰素γ（IFN-γ）和白细胞介素17A（IL-17A）的促炎因子和白细胞介素10（IL-10）的抗炎因子的百分比上调。 KO-wx2株。我们的数据表明，wx2基因在小鼠体内寄生虫的生命周期和毒力过程中起着重要作用。此外，它在宿主的免疫反应中也起着重要作用，主要是通过Th1和Th17细胞免疫，而不是Th2。KO感染小鼠的淋巴结中干扰素γ（IFN-γ）和白介素17A（IL-17A）的促炎因子和白介素10（IL-10）的抗炎因子的表达上调-wx2应变。我们的数据表明，wx2基因在小鼠体内寄生虫的生命周期和毒力过程中起着重要作用。此外，它在宿主的免疫反应中也起着重要作用，主要是通过Th1和Th17细胞免疫，而不是Th2。KO感染小鼠的淋巴结中干扰素γ（IFN-γ）和白介素17A（IL-17A）的促炎因子和白介素10（IL-10）的抗炎因子的表达上调-wx2应变。我们的数据表明，wx2基因在小鼠体内寄生虫的生命周期和毒力过程中起着重要作用。此外，它在宿主的免疫反应中也起着重要作用，主要是通过Th1和Th17细胞免疫，而不是Th2。