Unglycosylated Soluble SARS-CoV-2 Receptor Binding Domain (RBD) Produced in E. coli Combined with the Army Liposomal Formulation Containing QS21 (ALFQ) Elicits Neutralizing Antibodies against Mismatched Variants

Autor: Arasu Balasubramaniyam, Emma Ryan, Dallas Brown, Therwa Hamza, William Harrison, Michael Gan, Rajeshwer S. Sankhala, Wei-Hung Chen, Elizabeth J. Martinez, Jaime L. Jensen, Vincent Dussupt, Letzibeth Mendez-Rivera, Sandra Mayer, Jocelyn King, Nelson L. Michael, Jason Regules, Shelly Krebs, Mangala Rao, Gary R. Matyas, M. Gordon Joyce, Adrian H. Batchelor, Gregory D. Gromowski, Sheetij Dutta
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Vaccines, Vol 11, Iss 1, p 42 (2022)
Druh dokumentu: article
ISSN: 2076-393X
DOI: 10.3390/vaccines11010042
Popis: The emergence of novel potentially pandemic pathogens necessitates the rapid manufacture and deployment of effective, stable, and locally manufacturable vaccines on a global scale. In this study, the ability of the Escherichia coli expression system to produce the receptor binding domain (RBD) of the SARS-CoV-2 spike protein was evaluated. The RBD of the original Wuhan-Hu1 variant and of the Alpha and Beta variants of concern (VoC) were expressed in E. coli, and their biochemical and immunological profiles were compared to RBD produced in mammalian cells. The E. coli-produced RBD variants recapitulated the structural character of mammalian-expressed RBD and bound to human angiotensin converting enzyme (ACE2) receptor and a panel of neutralizing SARS-CoV-2 monoclonal antibodies. A pilot vaccination in mice with bacterial RBDs formulated with a novel liposomal adjuvant, Army Liposomal Formulation containing QS21 (ALFQ), induced polyclonal antibodies that inhibited RBD association to ACE2 in vitro and potently neutralized homologous and heterologous SARS-CoV-2 pseudoviruses. Although all vaccines induced neutralization of the non-vaccine Delta variant, only the Beta RBD vaccine produced in E. coli and mammalian cells effectively neutralized the Omicron BA.1 pseudovirus. These outcomes warrant further exploration of E. coli as an expression platform for non-glycosylated, soluble immunogens for future rapid response to emerging pandemic pathogens.
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