Production of a SARS-CoV-2 Virus-Like-Particle System to Investigate Viral Life Cycles In Vitro.

The severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus-like particle (SC2-VLP) method offers a powerful and accessible tool for studying the SARS-CoV-2 life cycle without the need for biosafety level 3 (BSL-3) laboratories. This system effectively mimics critical stages of the viral life cycle, including assembly, genome packaging, and egress, using a luciferase reporter fused to the T20 signal for sensitive and precise detection of viral particle production. SC2-VLPs are generated by co-expressing SARS-CoV-2 structural proteins, including membrane (M), nucleocapsid (N), envelop (E), and spike (S), along with the RNA packaging signal in HEK-293T cells. Unlike traditional virus-like particle systems, the SC2-VLP method ensures accurate quantification and greater fidelity to the natural viral life cycle. Furthermore, compared to lentiviral pseudotyping methods, which are limited to studying viral entry through the incorporation of S protein into HIV-based lentiviral particles, the SC2-VLP system provides a more comprehensive platform for exploring multiple stages of SARS-CoV-2 biology. While this method bypasses the risks of handling live virus and expands accessibility. The SC2-VLP method represents a significant advancement in antiviral research and the development of therapeutic strategies against SARS-CoV-2.