Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Morfologia e Morfogênese Viral, Rio de Janeiro, RJ, Brasil.
Fundação Oswaldo Cruz-Fiocruz, Instituto Oswaldo Cruz, Laboratório de Vírus Respiratórios e do Sarampo, Rio de Janeiro, RJ, Brasil.
Mem Inst Oswaldo Cruz. 2021 Feb 8;116:e200443. doi: 10.1590/0074-02760200443. eCollection 2021.
The coronaviruses (CoVs) called the attention of the world for causing outbreaks of severe acute respiratory syndrome (SARS-CoV), in Asia in 2002-03, and respiratory disease in the Middle East (MERS-CoV), in 2012. In December 2019, yet again a new coronavirus (SARS-CoV-2) first identified in Wuhan, China, was associated with a severe respiratory infection, known today as COVID-19. This new virus quickly spread throughout China and 30 additional countries. As result, the World Health Organization (WHO) elevated the status of the COVID-19 outbreak from emergency of international concern to pandemic on March 11, 2020. The impact of COVID-19 on public health and economy fueled a worldwide race to approve therapeutic and prophylactic agents, but so far, there are no specific antiviral drugs or vaccines available. In current scenario, the development of in vitro systems for viral mass production and for testing antiviral and vaccine candidates proves to be an urgent matter.
The objective of this paper is study the biology of SARS-CoV-2 in Vero-E6 cells at the ultrastructural level.
In this study, we documented, by transmission electron microscopy and real-time reverse transcription polymerase chain reaction (RT-PCR), the infection of Vero-E6 cells with SARS-CoV-2 samples isolated from Brazilian patients.
The infected cells presented cytopathic effects and SARS-CoV-2 particles were observed attached to the cell surface and inside cytoplasmic vesicles. The entry of the virus into cells occurred through the endocytic pathway or by fusion of the viral envelope with the cell membrane. Assembled nucleocapsids were verified inside rough endoplasmic reticulum cisterns (RER). Viral maturation seemed to occur by budding of viral particles from the RER into smooth membrane vesicles.
Therefore, the susceptibility of Vero-E6 cells to SARS-CoV-2 infection and the viral pathway inside the cells were demonstrated by ultrastructural analysis.
冠状病毒（CoVs）在 2002-03 年于亚洲引发严重急性呼吸综合征（SARS-CoV）爆发，在 2012 年于中东引发呼吸疾病（MERS-CoV），引起了全世界的关注。2019 年 12 月，在中国武汉首次发现的另一种新型冠状病毒（SARS-CoV-2）与一种严重的呼吸道感染有关，现在称为 COVID-19。这种新病毒迅速在中国和其他 30 个国家传播。因此，世界卫生组织（WHO）于 2020 年 3 月 11 日将 COVID-19 疫情的紧急状态提升为国际关注的突发公共卫生事件。COVID-19 对公共卫生和经济的影响引发了全球范围内对抗病毒药物和预防性药物的批准竞赛，但到目前为止，尚无特效抗病毒药物或疫苗。在当前情况下，开发用于病毒大量生产以及测试抗病毒和疫苗候选物的体外系统被证明是当务之急。
本文旨在从超微结构水平研究 SARS-CoV-2 在 Vero-E6 细胞中的生物学特性。
在这项研究中，我们通过透射电子显微镜和实时逆转录聚合酶链反应（RT-PCR）记录了从巴西患者分离的 SARS-CoV-2 样本感染 Vero-E6 细胞的情况。
受感染的细胞出现细胞病变效应，并且观察到 SARS-CoV-2 颗粒附着在细胞表面和细胞质囊泡内。病毒进入细胞是通过内吞途径或病毒包膜与细胞膜融合发生的。在粗面内质网腔（RER）内验证了组装的核衣壳。病毒成熟似乎是通过病毒粒子从 RER 出芽到光滑膜囊泡而发生的。
因此，通过超微结构分析证明了 Vero-E6 细胞对 SARS-CoV-2 感染的敏感性和细胞内的病毒途径。
