The Interaction between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein with Angiotensin converting enzyme 2 (ACE2) on the host cells is a crucial step for the viral entry and infection. Therefore, investigating the molecular mechanism underlying the interaction is of great importance for the prevention of the infection of SARS-CoV-2. In this study, we aimed to establish a virus-free in vitro system to study the interaction between the spike protein and host cells of SARS-CoV-2. Our results show that ACE2-overexpressing HEK293T cells are captured by immobilized spike S1 protein, and the cell capturing process can be inhibited by the receptor binding domain of the spike protein or antibodies against S protein. Furthermore, spike S1 protein variant with D614G mutant show a higher cell capturing ability than wild type spike S1 protein and stronger binding capacity of its receptor ACE2. In addition, the captured cells can be eluted as living cells for further investigation. This study provides a new in vitro system for investigating the interaction between SARS-CoV-2 and host cells and purifying ACE2-expressing cells.

中文翻译：

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使用体外细胞捕获系统研究 SARS-CoV-2 的刺突蛋白与表达 ACE2 的细胞之间的相互作用

严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 刺突蛋白与宿主细胞上的血管紧张素转化酶 2 (ACE2) 之间的相互作用是病毒进入和感染的关键步骤。因此，研究相互作用的分子机制对于预防SARS-CoV-2的感染具有重要意义。在这项研究中，我们旨在建立一个无病毒的体外系统来研究刺突蛋白与 SARS-CoV-2 宿主细胞之间的相互作用。我们的结果表明 ACE2 过表达的 HEK293T 细胞被固定化的刺突 S1 蛋白捕获，细胞捕获过程可以被刺突蛋白的受体结合域或抗 S 蛋白的抗体抑制。此外，具有 D614G 突变体的刺突 S1 蛋白变体显示出比野生型刺突 S1 蛋白更高的细胞捕获能力和更强的受体 ACE2 结合能力。此外，捕获的细胞可以作为活细胞洗脱以进行进一步研究。该研究为研究SARS-CoV-2与宿主细胞之间的相互作用以及纯化表达ACE2的细胞提供了一个新的体外系统。