Improved Expression of SARS-CoV-2 Spike RBD Using the Insect Cell-Baculovirus System

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

Viruses

MDPI

Lugar: Basel; Año: 2022 vol. 14

first_pagesettingsOrder Article ReprintsOpen AccessArticleImproved Expression of SARS-CoV-2 Spike RBD Using the Insect Cell-Baculovirus Systemby Joaquín Poodts 1,2,†,Ignacio Smith 1,2,†,Joaquín Manuel Birenbaum 1,2ORCID,María Sol Rodriguez 1,2,Luciano Montero 1,2,Federico Javier Wolman 1,2,Juan Ignacio Marfía 3,4,Silvina Noemí Valdez 3,4,Leonardo Gabriel Alonso 1,2,Alexandra Marisa Targovnik 1,2,*,‡ORCID andMaría Victoria Miranda 1,2,*,‡1Cátedra de Biotecnología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires (UBA), Junín 956, Buenos Aires 1113, Argentina2Instituto de Nanobiotecnología (NANOBIOTEC), Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Junín 956, Buenos Aires 1113, Argentina3Cátedra de Inmunología, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires (UBA), Junín 956, Buenos Aires 1113, Argentina4Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Junín 956, Buenos Aires 1113, Argentina*Authors to whom correspondence should be addressed.†These authors contributed equally to this work.‡These authors contributed equally to this work.Viruses 2022, 14(12), 2794; https://doi.org/10.3390/v14122794Received: 19 November 2022 / Revised: 10 December 2022 / Accepted: 12 December 2022 / Published: 15 December 2022(This article belongs to the Special Issue Applications of Baculoviruses: Expression Factories, Vaccines and VLPs, Gene Delivery Vectors, Biological Control and Virus Genetics Models)Download Browse Figures Versions NotesAbstractInsect 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 recombinant RBD (rRBD). For this reason, in the present study, we developed a process based on Sf9 insect cells to improve rRBD yield. rRBD was recovered from the supernatant of infected cells and easily purified by metal ion affinity chromatography, with a yield of 82% and purity higher than 95%. Expressed under a novel chimeric promoter (polh-pSeL), the yield of rRBD after purification was 21.1 ± 3.7 mg/L, which is the highest performance described in Sf9 cell lines. Finally, rRBD was successfully used in an assay to detect specific antibodies in COVID-19 serum samples. The efficient strategy herein described has the potential to produce high-quality rRBD in Sf9 cell line for diagnostic purpose.