Faculty of Life Science and Technology, Yunnan Provincial Center for Molecular Medicine, Kunming University of Science and Technology, Kunming, China.
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, China.
Front Cell Infect Microbiol. 2021 Jun 25;11:687338. doi: 10.3389/fcimb.2021.687338. eCollection 2021.
Sexual transmission of Zika Virus (ZIKV) elevates the risk of its dissemination in the female reproductive tract and causes a serious threat to the fetus. However, the available animal models are not appropriate to investigate sexual transmission, dynamics of ZIKV infection, replication, and shedding. The use of tree shrew as a small animal model of ZIKV vaginal infection was assessed in this study. A total of 23 sexually mature female tree shrews were infected with ZIKV GZ01 the intravaginal route. There was no significant difference in change of body weight, and the temperature between ZIKV infected and control animals. Viral RNA loads were detected in blood, saliva, urine, and vaginal douching. ZIKV RNA was readily detected in vaginal lavage of 22 animals (95.65%, 22/23) at 1 dpi, and viral load ranged from 104.46 to 107.35 copies/ml, and the peak of viral load appeared at 1 dpi. The expression of key inflammatory genes, such as IL6, 8, CCL5, TNF-a, and CXCL9, was increased in the spleen of ZIKV infected animals. In the current study, female tree shrews have been successfully infected with ZIKV through the vaginal route for the first time. Interestingly, at first, ZIKV replicates at the local site of infection and then spreads throughout the host body to develop a robust systemic infection and mounted a protective immune response. This small animal model is not only valuable for exploring ZIKV sexual transmission and may also help to explain the cause of debilitating manifestations of the fetus .
寨卡病毒（ZIKV）的性传播会增加其在女性生殖道中传播的风险，并对胎儿造成严重威胁。然而，现有的动物模型并不适合研究性传播、ZIKV 感染、复制和脱落的动力学。本研究评估了树鼩作为 ZIKV 阴道感染的小动物模型。共 23 只性成熟雌性树鼩通过阴道途径感染 ZIKV GZ01。感染组和对照组动物的体重和体温均无显著差异。在血液、唾液、尿液和阴道冲洗液中检测到病毒 RNA 载量。在 1dpi，22 只动物（95.65%，22/23）的阴道灌洗液中可迅速检测到 ZIKV RNA，病毒载量范围为 104.46 至 107.35 拷贝/ml，病毒载量峰值出现在 1dpi。感染动物脾脏中关键炎症基因（如 IL6、8、CCL5、TNF-a 和 CXCL9）的表达增加。在本研究中，雌性树鼩首次通过阴道途径成功感染 ZIKV。有趣的是，ZIKV 首先在感染部位局部复制，然后传播到宿主全身，引发强烈的全身感染并产生保护性免疫反应。这种小动物模型不仅对探索 ZIKV 的性传播有价值，也有助于解释胎儿致残表现的原因。
