Baculovirus-Free SARS-CoV-2 Virus-like Particle Production in Insect Cells for Rapid Neutralization Assessment

Jaron, Marcel; Lehky, Michael; Zara, Marta; Zaydowicz, Chris Nicole; Lak, Aidin; Ballmann, Rico; Heine, Philip Alexander; Wenzel, Esther Veronika; Schneider, Kai-Thomas; Bertoglio, Federico; Kempter, Susanne; Köster, Reinhard Wolfgang; Barbieri, Silvia Stella; Heuvel, Joop van den; Hust, Michael; Dübel, Stefan and Schubert, Maren (2022): Baculovirus-Free SARS-CoV-2 Virus-like Particle Production in Insect Cells for Rapid Neutralization Assessment. In: Viruses, Vol. 14, No. 10, 2087

Abstract

Virus-like particles (VLPs) resemble authentic virus while not containing any genomic information. Here, we present a fast and powerful method for the production of SARS-CoV-2 VLP in insect cells and the application of these VLPs to evaluate the inhibition capacity of monoclonal antibodies and sera of vaccinated donors. Our method avoids the baculovirus-based approaches commonly used in insect cells by employing direct plasmid transfection to co-express SARS-CoV-2 envelope, membrane, and spike protein that self-assemble into VLPs. After optimization of the expression plasmids and vector ratios, VLPs with an similar to 145 nm diameter and the typical Corona aura were obtained, as confirmed by nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). Fusion of the membrane protein to GFP allowed direct quantification of binding inhibition to angiotensin II-converting enzyme 2 (ACE2) on cells by therapeutic antibody candidates or sera from vaccinated individuals. Neither VLP purification nor fluorescent labeling by secondary antibodies are required to perform these flow cytometric assays.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• Language: English