Department of Chemical and Biological Engineering, Princeton University, Princeton, United States.
Princeton University Small Molecule Screening Center, Princeton University, Princeton, United States.
Elife. 2021 Apr 23;10:e65962. doi: 10.7554/eLife.65962.
Many enveloped viruses induce multinucleated cells (syncytia), reflective of membrane fusion events caused by the same machinery that underlies viral entry. These syncytia are thought to facilitate replication and evasion of the host immune response. Here, we report that co-culture of human cells expressing the receptor ACE2 with cells expressing SARS-CoV-2 spike, results in synapse-like intercellular contacts that initiate cell-cell fusion, producing syncytia resembling those we identify in lungs of COVID-19 patients. To assess the mechanism of spike/ACE2-driven membrane fusion, we developed a microscopy-based, cell-cell fusion assay to screen ~6000 drugs and >30 spike variants. Together with quantitative cell biology approaches, the screen reveals an essential role for biophysical aspects of the membrane, particularly cholesterol-rich regions, in spike-mediated fusion, which extends to replication-competent SARS-CoV-2 isolates. Our findings potentially provide a molecular basis for positive outcomes reported in COVID-19 patients taking statins and suggest new strategies for therapeutics targeting the membrane of SARS-CoV-2 and other fusogenic viruses.
许多包膜病毒诱导多核细胞（合胞体），反映了由病毒进入所依赖的相同机制引起的膜融合事件。这些合胞体被认为有助于复制和逃避宿主免疫反应。在这里，我们报告说，表达受体 ACE2 的人细胞与表达 SARS-CoV-2 刺突蛋白的细胞共培养，会导致类似于突触的细胞间接触，从而引发细胞融合，产生类似于我们在 COVID-19 患者肺部中发现的合胞体。为了评估刺突/ACE2 驱动的膜融合机制，我们开发了一种基于显微镜的细胞-细胞融合测定法，筛选了约 6000 种药物和 >30 种刺突变体。与定量细胞生物学方法一起，该筛选揭示了膜的生物物理特性（特别是富含胆固醇的区域）在刺突介导的融合中的重要作用，这延伸到具有复制能力的 SARS-CoV-2 分离株。我们的发现可能为 COVID-19 患者服用他汀类药物后报告的积极结果提供了分子基础，并为针对 SARS-CoV-2 和其他融合病毒膜的治疗策略提供了新的思路。
