Negi Vashi, Kuhn Richard J
Department of Biological Sicences, Purdue University, West Lafayette, Indiana, USA.
Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, Indiana, USA.
J Virol. 2025 May 20;99(5):e0225224. doi: 10.1128/jvi.02252-24. Epub 2025 Apr 30.
A major hindrance to the identification of new drug targets and the large-scale testing of new or existing compound libraries against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is that research on the virus is restricted to biosafety level 3 (BSL-3) laboratories. In such cases, BSL-2 surrogate systems or chimeric and attenuated versions of the virus are developed for safer, faster, and cheaper examination of the stages of the virus life cycle and specific drug targets. In this study, we describe a BSL-2 chimeric viral system utilizing a Sindbis virus background as a tool to study one such target, the SARS-CoV-2 Envelope (E) protein channel activity. This protein is fully conserved between SARS-CoV and SARS-CoV-2 variants of concern (VOCs), except for a threonine to isoleucine mutation in the Omicron variant, making the E ion channel domain an attractive antiviral target for combination therapy. Using a BSL-2-chimeric system, we have been able to show similar inhibition profiles using channel inhibitors as previously reported for E-channel inhibition in authentic SARS-CoV-2. This system has the potential to allow faster initial screening of E-channel inhibitors and can be useful in developing broad-spectrum antivirals against viral channel proteins.IMPORTANCEDespite its importance in viral infections, no antivirals exist against the ion channel activity of the SARS-CoV-2 Envelope (E) protein. The E protein is highly conserved among SARS-CoV-2 variants, making it an attractive target for antiviral therapies. Research on SARS-CoV-2 is restricted to BSL-3 laboratories, creating a bottleneck for screening potential antiviral compounds. This study presents a BSL-2 chimeric system using a Sindbis virus background to study the ion channel activity of the E protein. This novel BSL-2 system bypasses this limitation, offering a safer and faster approach for the initial screening of ion channel inhibitors. By replicating the channel inhibition profiles of authentic SARS-CoV-2 in a more accessible system, this research paves the way for the development of broad-spectrum antivirals against viral channel proteins, potentially expediting the discovery of life-saving treatments for COVID-19 and other viral diseases.
确定新的药物靶点以及针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）对新的或现有的化合物文库进行大规模测试的一个主要障碍是，对该病毒的研究仅限于生物安全3级（BSL-3）实验室。在这种情况下，人们开发了BSL-2替代系统或病毒的嵌合及减毒版本，以便更安全、快速和廉价地检测病毒生命周期的各个阶段以及特定的药物靶点。在本研究中，我们描述了一种利用辛德毕斯病毒背景的BSL-2嵌合病毒系统，作为研究一个此类靶点——SARS-CoV-2包膜（E）蛋白通道活性的工具。除了奥密克戎变体中有一个苏氨酸到异亮氨酸的突变外，该蛋白在SARS-CoV和SARS-CoV-2关注变体（VOCs）之间完全保守，这使得E离子通道结构域成为联合治疗中一个有吸引力的抗病毒靶点。使用BSL-2嵌合系统，我们能够显示出与之前报道的在真实SARS-CoV-2中抑制E通道相似的抑制谱。该系统有可能加快对E通道抑制剂的初步筛选，并有助于开发针对病毒通道蛋白的广谱抗病毒药物。
重要性
尽管SARS-CoV-2包膜（E）蛋白的离子通道活性在病毒感染中很重要，但目前尚无针对该活性的抗病毒药物。E蛋白在SARS-CoV-2变体中高度保守，使其成为抗病毒治疗的一个有吸引力的靶点。对SARS-CoV-2的研究仅限于BSL-3实验室，这为筛选潜在的抗病毒化合物造成了瓶颈。本研究提出了一种利用辛德毕斯病毒背景的BSL-2嵌合系统来研究E蛋白的离子通道活性。这个新颖的BSL-2系统绕过了这一限制，为离子通道抑制剂的初步筛选提供了一种更安全、更快的方法。通过在一个更容易操作的系统中重现真实SARS-CoV-2的通道抑制谱，这项研究为开发针对病毒通道蛋白的广谱抗病毒药物铺平了道路，有可能加快发现针对COVID-19和其他病毒疾病的救命疗法。
