{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,29]],"date-time":"2026-03-29T14:31:33Z","timestamp":1774794693097,"version":"3.50.1"},"reference-count":40,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,11,4]],"date-time":"2020-11-04T00:00:00Z","timestamp":1604448000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","award":["OV5-170348"],"award-info":[{"award-number":["OV5-170348"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000196","name":"Canada Foundation for Innovation","doi-asserted-by":"publisher","award":["32904"],"award-info":[{"award-number":["32904"]}],"id":[{"id":"10.13039\/501100000196","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001804","name":"Canada Research Chairs","doi-asserted-by":"publisher","award":["CRC-240394"],"award-info":[{"award-number":["CRC-240394"]}],"id":[{"id":"10.13039\/501100001804","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Vaccine design strategies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are focused on the Spike protein or its subunits as the main antigen target of neutralizing antibodies. In this work, we propose rapid production methods of an extended segment of the Spike Receptor Binding Domain (RBD) in HEK293SF cells cultured in suspension, in serum-free media, as a major component of a COVID-19 subunit vaccine under development. The expression of RBD, engineered with a sortase-recognition motif for protein-based carrier coupling, was achieved at high yields by plasmid transient transfection or human type-5-adenoviral infection of the cells, in a period of only two and three weeks, respectively. Both production methods were evaluated in 3L-controlled bioreactors with upstream and downstream bioprocess improvements, resulting in a product recovery with over 95% purity. Adenoviral infection led to over 100 \u00b5g\/mL of RBD in culture supernatants, which was around 7-fold higher than levels obtained in transfected cultures. The monosaccharide and sialic acid content was similar in the RBD protein from the two production approaches. It also exhibited a proper conformational structure as recognized by monoclonal antibodies directed against key native Spike epitopes. Efficient direct binding to ACE2 was also demonstrated at similar levels in RBD obtained from both methods and from different production lots. Overall, we provide bioprocess-related data for the rapid, scalable manufacturing of low cost RBD based vaccines against SARS-CoV-2, with the added value of making a functional antigen available to support further research on uncovering mechanisms of virus binding and entry as well as screening for potential COVID-19 therapeutics.<\/jats:p>","DOI":"10.3390\/vaccines8040654","type":"journal-article","created":{"date-parts":[[2020,11,4]],"date-time":"2020-11-04T10:29:00Z","timestamp":1604485740000},"page":"654","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Rapid High-Yield Production of Functional SARS-CoV-2 Receptor Binding Domain by Viral and Non-Viral Transient Expression for Pre-Clinical Evaluation"],"prefix":"10.3390","volume":"8","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1295-8323","authenticated-orcid":false,"given":"Omar","family":"Farn\u00f3s","sequence":"first","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alina","family":"Venereo-S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xingge","family":"Xu","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Cindy","family":"Chan","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shantoshini","family":"Dash","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hanan","family":"Chaabane","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Janelle","family":"Sauvageau","sequence":"additional","affiliation":[{"name":"Human Health Therapeutics, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fouad","family":"Brahimi","sequence":"additional","affiliation":[{"name":"Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, QC H3T 1E2, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6884-8815","authenticated-orcid":false,"given":"Uri","family":"Saragovi","sequence":"additional","affiliation":[{"name":"Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, QC H3T 1E2, Canada"},{"name":"Department of Pharmacology, Department of Ophthalmology and Visual Science, McGill University, Montr\u00e9al, QC H3A 1A3, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9323-1638","authenticated-orcid":false,"given":"Denis","family":"Leclerc","sequence":"additional","affiliation":[{"name":"D\u00e9partement de Microbiologie-Infectiologie et d\u2019immunologie, Facult\u00e9 de M\u00e9decine, Universit\u00e9 Laval, Qu\u00e9bec City, QC G1V 0A6, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amine A.","family":"Kamen","sequence":"additional","affiliation":[{"name":"Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montr\u00e9al, QC H3A 0E9, Canada"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2020,11,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ashour, H.M., Elkhatib, W.F., Rahman, M.M., and Elshabrawy, H.A. 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