Production of SARS-CoV-2 Spike RBD using the Baculovirus Expression System

JOAQUÍN POODTS; IGNACIO SMITH; JOAQUÍN MANUEL BIRENBAUM; MARÍA SOL RODRÍGUEZ; LUCIANO MONTERO; FEDERICO JAVIER WOLMAN; JUAN IGNACIO MARFIA; SILVINA NOEMÍ VALDEZ; LEONARDO GABRIEL ALONSO; ALEXANDRA MARISA TARGOVNIK; MARÍA VICTORIA MIRANDA

San Francisco

Conferencia; ACS Fall 2023; 2023

ACS

Insect cell-baculovirus expression vector system is one of the most established platforms to produce biological products, and it plays a fundamental role in the context of COVID-19 emergency, providing recombinant proteins for treatment, diagnosis, and prevention. SARS-CoV-2 infection is mediated by the interaction of the spike glycoprotein trimer via its receptor-binding domain (RBD) with the host´s cellular receptor. As RBD is required for many applications, in the context of pandemic it is important to meet the challenge of producing a high amount of pure recombinant RBD (rRBD). For this reason, in the present study, we developed a process based on Sf9 insect cells to improve rRBD yield. Expressed under a novel chimeric promoter (polh-pSeL), rRBD yield was 25.6 ± 3.0 mg/L culture, which is the highest performance described in Sf9 cell lines. rRBD was recovered from the supernatant of infected cells and easily purified in only one step by metal ion affinity chromatography using Nuvia IMAC Ni-NTA Resin (BioRad), with a yield of 82% and purity higher than 95%. Finally, rRBD was successfully used in an assay to detect specific antibodies in serum samples from COVID-19 serum samples. The efficient strategy herein described has the potential to produce high-quality rRBD in Sf9 cell line for different applications.