Construction of an acute toxoplasma encephalitis mouse model by the stereotaxic surgery with RH toxoplasma trophozoites

Kaiwei SI; Jianxin Liu; Feng WU; Xiaoqi LI; Zihao FU; Jinhua Gong; Junyang Wang; Yanbin Cheng

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Construction of an acute toxoplasma encephalitis mouse model by the stereotaxic surgery with RH toxoplasma trophozoites

VernacularTitle:RH株弓形虫颅内定位注射建立急性弓形虫脑炎小鼠模型的研究
Author: Kaiwei SI ¹ ; Jianxin LIU ² ; Feng WU ³ ; Xiaoqi LI ¹ ; Zihao FU ⁴ ; Jinhua GONG ⁵ ; Junyang WANG ¹ ; Yanbin CHENG ¹
Author Information

1. Department of Pathogenic Biology and Immunology, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
2. Institute of Neurobiology, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
3. Center of Medical Experiment Teaching for Postgraduates, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
4. Zonglian Experimental Class of Grade 2018, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
5. Basic Medicine Class of Grade 2019, Xi’an Jiaotong University Health Science Center, Xi’an 710061, China
Publication Type:Journal Article
Keywords: toxoplasma; stereotaxic surgery; hippocampus; toxoplasma encephalitis
From: Journal of Xi'an Jiaotong University(Medical Sciences) 2023;44(5):746-754
CountryChina
Language:Chinese
Abstract: 【Objective】 To construct an acute toxoplasma encephalitis mouse model by observing the pathological changes in the hippocampus of mice infected with Toxoplasma gondii strain RH. 【Methods】 The quantitative RH Toxoplasma gondii (100, 500, and 1 000 trophozoites) were injected into the hippocampal CA1 region of mice by the stereotaxic surgery; the survival status of mice was observed. Giemsa staining was used to observe the changes of toxoplasma in mouse ascites and brain tissue homogenates. Nissl staining and HE staining were used to observe the pathological changes of hippocampal nerve tissue. The distribution of Toxoplasma gondii in brain tissue was observed by immunohistochemical ABC method. 【Results】 The RH Toxoplasma gondii infected mice showed obvious symptoms such as arched back, bristling hair, abdominal distension, subtle tremor and hemiplegia on the fourth day of infection. The survival of mice in 100 trophozoites group was longer, no trophozoites of Toxoplasma gondii were found in ascites, a few pseudocysts were found in brain tissue homogenates after infected for 96 hours, and more trophozoites were found after death. Nysl staining and HE staining showed more tissue necrosis foci and loss of nerve cells in CA1 area after infected 144 h. The injury aggravated with the prolongation of infection time. Toxoplasma trophozoites were found in ascites and brain homogenates of mice in 500 and 1000 trophozoites groups. Nissl staining revealed neuronal loss and massive necrosis in the hippocampus. HE staining showed necrosis and inflammatory cell infiltration. The brain tissue injury significantly aggravated compared with 100 trophozoites group. The distribution of Toxoplasma gondii in the necrotic foci was confirmed by immunohistochemistry. 【Conclusion】 The survival of 100 trophozoite mice infected with Toxoplasma gondii strain RH was longer, and the pathological changes of brain tissue gradually aggravated. The damage was relatively confined to the brain tissue, and the mice showed typical symptoms of toxoplasma encephalitis. Therefore, the mouse model of acute toxoplasma encephalitis can be constructed by localized infection of 100 toxoplasma trophozoites, which can lay a foundation for future research on the mechanism of toxoplasma injury to cranial nerves.