Abstract
The glycosylated receptor-binding domain (glycoRBD) of SARS-CoV-2 can induce protective neutralizing antibodies to function as a vaccine. However, it is unclear whether vaccines using non-glycosylated RBD (non-glycoRBD) can induce protective immunity. Here, we report the efficacy of a SARS-CoV-2 non-glycoRBD vaccine produced by prokaryotic system in mice. The recombinant non-glycoRBD protein was overexpressed in Escherichia coli in the form of inclusion bodies, and was obtained after renaturation and three-step purification. From HPLC analysis, the purity of the RBD was 99%. Additionally, angiotensin converting enzyme 2 (ACE2)-binding assays revealed that E.coli-derived non-glycoRBD had binding activity consistent with glycoRBD. The RBD was formulated with CpG ODN and Al(OH) 3 adjuvants and the obtained RBD candidate vaccine elicited potent antibody responses and neutralized SARS-CoV-2 wild-type, Delta, and Omicron pseudoviruses. In summary, our data showed that a non-glycoRBD candidate vaccine produced by E.coli provided a robust immune response and had pseudovirus neutralizing activity, making it a solid candidate vaccine for protection against SARS-CoV-2.
Keywords: Escherichia coli; Neutralizing antibody; Receptor-binding domain (RBD); SARS-CoV-2.
【저자키워드】 neutralizing antibody, SARS-CoV-2, Receptor-binding domain (RBD), Escherichia coli, 【초록키워드】 SARS-CoV-2, Efficacy, Vaccine, immune response, Antibody Response, Delta, omicron, Protein, Neutralizing activity, Receptor-binding domain, protective immunity, pseudovirus, mice, RBD, adjuvant, HPLC, CpG, Analysis, binding activity, pseudoviruses, enzyme, domain, candidate vaccine, wild-type, purification, Inclusion, neutralized, robust, produced, provided, the RBD, induce, elicited, overexpressed, glycosylated, was obtained, Escherichia, protective neutralizing antibody, 【제목키워드】 mice, Neutralizing antibody response, SARS-CoV-2 RBD, robust, elicited,