Division of Global Epidemiology, International Institute for Zoonosis Control, Hokkaido Universitygrid.39158.36, Sapporo, Japan.
International Collaboration Unit, International Institute for Zoonosis Control, Hokkaido Universitygrid.39158.36, Sapporo, Japan.
Microbiol Spectr. 2022 Aug 31;10(4):e0087022. doi: 10.1128/spectrum.00870-22. Epub 2022 Jul 11.
Severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 have a single envelope glycoprotein (S protein) that binds to human angiotensin-converting enzyme 2 (ACE2) on the host cell membrane. Previous mutational scanning studies have suggested that some substitutions corresponding to single nucleotide variants (SNVs) in human ACE2 affect the binding affinity to the receptor binding domain (RBD) of the SARS-CoV-2 S protein. However, the importance of these substitutions in actual virus infection is still unclear. In this study, we investigated the effects of the reported ACE2 SNV substitutions on the entry of SARS-CoV and SARS-CoV-2 into cells, using vesicular stomatitis Indiana virus (VSIV) pseudotyped with S proteins of these coronaviruses (CoVs). HEK293T cells transfected with plasmids expressing ACE2 having each SNV substitution were infected with the pseudotyped VSIVs and relative infectivities were determined compared to the cells expressing wild-type ACE2. We found that some of the SNV substitutions positively or negatively affected the infectivities of the pseudotyped viruses. Particularly, the H505R substitution significantly enhanced the infection with the pseudotyped VSIVs, including those having the substitutions found in the S protein RBD of SARS-CoV-2 variants of concern. Our findings suggest that human ACE2 SNVs may potentially affect cell susceptibilities to SARS-CoV and SARS-CoV-2. SARS-CoV and SARS-CoV-2 are known to cause severe pneumonia in humans. The S protein of these CoVs binds to the ACE2 molecule on the plasma membrane and mediates virus entry into cells. The interaction between the S protein and ACE2 is thought to be important for host susceptibility to these CoVs. Although previous studies suggested that some SNV substitutions in ACE2 might affect the binding to the S protein, it remains elusive whether these SNV substitutions actually alter the efficiency of the entry of SARS CoVs into cells. We analyzed the impact of the ACE2 SNVs on the cellular entry of SARS CoVs using pseudotyped VSIVs having the S protein on the viral surface. We found that some of the SNV substitutions positively or negatively affected the infectivities of the viruses. Our data support the notion that genetic polymorphisms of ACE2 may potentially influence cell susceptibilities to SARS CoVs.
严重急性呼吸综合征冠状病毒（SARS-CoV）和 SARS-CoV-2 都有一个包膜糖蛋白（S 蛋白），它与宿主细胞膜上的人血管紧张素转换酶 2（ACE2）结合。以前的突变扫描研究表明，人类 ACE2 中的一些对应于单核苷酸变异（SNV）的取代会影响 SARS-CoV-2 S 蛋白受体结合域（RBD）的结合亲和力。然而，这些取代在实际病毒感染中的重要性仍不清楚。在这项研究中，我们使用这些冠状病毒的 S 蛋白假型水疱性口炎印度病毒（VSIV）研究了报道的 ACE2 SNV 取代对 SARS-CoV 和 SARS-CoV-2 进入细胞的影响。用表达每种 SNV 取代的 ACE2 的质粒转染 HEK293T 细胞，并用假型 VSIV 感染细胞，并与表达野生型 ACE2 的细胞相比确定相对感染性。我们发现，一些 SNV 取代会积极或消极地影响假型病毒的感染性。特别是，H505R 取代显著增强了假型 VSIV 的感染，包括那些在 SARS-CoV-2 变体的 S 蛋白 RBD 中发现的取代。我们的研究结果表明，人类 ACE2 SNV 可能会潜在地影响细胞对 SARS-CoV 和 SARS-CoV-2 的易感性。SARS-CoV 和 SARS-CoV-2 已知会导致人类严重肺炎。这些 CoV 的 S 蛋白与质膜上的 ACE2 分子结合，并介导病毒进入细胞。S 蛋白与 ACE2 的相互作用被认为对这些 CoV 的宿主易感性很重要。尽管以前的研究表明 ACE2 中的一些 SNV 取代可能会影响与 S 蛋白的结合，但实际上这些 SNV 取代是否会改变 SARS CoV 进入细胞的效率仍不清楚。我们使用表面具有 S 蛋白的假型 VSIV 分析了 ACE2 SNV 对 SARS CoV 细胞进入的影响。我们发现，一些 SNV 取代会积极或消极地影响病毒的感染性。我们的数据支持这样的观点，即 ACE2 的遗传多态性可能会潜在地影响细胞对 SARS CoV 的易感性。
