KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, Herestraat 49, 3000, Leuven, Belgium.
KU Leuven, Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Clinical and Epidemiological Virology, Herestraat 49, 3000, Leuven, Belgium.
Antiviral Res. 2022 Jul;203:105342. doi: 10.1016/j.antiviral.2022.105342. Epub 2022 May 18.
Despite the great success of the administered vaccines against SARS-CoV-2, the virus can still spread, as evidenced by the current circulation of the highly contagious Omicron variant. This emphasizes the additional need to develop effective antiviral countermeasures. In the context of early preclinical studies for antiviral assessment, robust cellular infection systems are required to screen drug libraries. In this study, we reported the implementation of a human glioblastoma cell line, stably expressing ACE2, in a SARS-CoV-2 cytopathic effect (CPE) reduction assay. These glioblastoma cells, designated as U87.ACE2, expressed ACE2 and cathepsin B abundantly, but had low cellular levels of TMPRSS2 and cathepsin L. The U87.ACE2 cells fused highly efficiently and quickly with SARS-CoV-2 spike expressing cells. Furthermore, upon infection with SARS-CoV-2 wild-type virus, the U87.ACE2 cells displayed rapidly a clear CPE that resulted in complete cell lysis and destruction of the cell monolayer. By means of several readouts we showed that the U87.ACE2 cells actively replicate SARS-CoV-2. Interestingly, the U87.ACE2 cells could be successfully implemented in an MTS-based colorimetric CPE reduction assay, providing IC values for Remdesivir and Nirmatrelvir in the (low) nanomolar range. Lastly, the U87.ACE2 cells were consistently permissive to all tested SARS-CoV-2 variants of concern, including the current Omicron variant. Thus, ACE2 expressing glioblastoma cells are highly permissive to SARS-CoV-2 with productive viral replication and with the induction of a strong CPE that can be utilized in high-throughput screening platforms.
尽管针对 SARS-CoV-2 的疫苗接种取得了巨大成功，但病毒仍在传播，目前高度传染性的奥密克戎变体的流行就证明了这一点。这强调了开发有效抗病毒对策的额外需求。在用于抗病毒评估的早期临床前研究中，需要有强大的细胞感染系统来筛选药物库。在这项研究中，我们报告了在 SARS-CoV-2 细胞病变效应（CPE）减少测定中实施稳定表达 ACE2 的人胶质母细胞瘤细胞系。这些胶质母细胞瘤细胞系命名为 U87.ACE2，大量表达 ACE2 和组织蛋白酶 B，但细胞中 TMPRSS2 和组织蛋白酶 L 的水平较低。U87.ACE2 细胞与表达 SARS-CoV-2 刺突的细胞高效且快速融合。此外，在用 SARS-CoV-2 野生型病毒感染后，U87.ACE2 细胞迅速表现出明显的 CPE，导致细胞完全裂解和细胞单层破坏。通过多种读数，我们表明 U87.ACE2 细胞能够主动复制 SARS-CoV-2。有趣的是，U87.ACE2 细胞可以成功地应用于基于 MTS 的比色 CPE 减少测定中，为瑞德西韦和奈玛特韦提供了在纳摩尔范围内的 IC 值。最后，U87.ACE2 细胞对所有测试的 SARS-CoV-2 变体均保持易感性，包括当前的奥密克戎变体。因此，表达 ACE2 的胶质母细胞瘤细胞对 SARS-CoV-2 具有高度易感性，可进行有效的病毒复制，并诱导强烈的 CPE，可用于高通量筛选平台。
