Production of SARS-CoV-2 virus-like particles as a vaccine candidate in stable cell lines through inducible E and M protein expression.

Stable cell lines were established by constructing two plasmids, in which E and M expression was controlled by an inducible Tet-on promoter and they were placed adjacent to S and N, respectively. A HEK293T cell line for stable expression of SARS-CoV-2 VLPs was established by co-selection with two antibiotics, puromycin and blasticidin.

Using a Countstar instrument, the study assessed cell numbers in cell suspensions during quality assessment in the 2025 BMC biotechnology study.