The Receptor-Binding Domain (RBD) of the Spike (S) protein from Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has glycosylation sites which can limit the production of reliable antigens expressed in prokaryotic platforms, due to glycan-mediated evasion of the host immune response. However, protein regions without glycosylated residues capable of inducing neutralizing antibodies could be useful for antigen production in systems that do not carry the glycosylation machinery. To test this hypothesis, the potential antigens NG06 and NG19, located within the non-glycosylated S-RBD region, were selected and expressed in Escherichia coli , purified by FPLC and employed to determine their immunogenic potential through detection of antibodies in serum from immunized rabbits, mice, and COVID-19 patients. IgG antibodies from sera of COVID-19-recovered patients detected the recombinant antigens NG06 and NG19 (A 450 nm = 0.80 ± 0.33; 1.13 ± 0.33; and 0.11 ± 0.08 for and negatives controls, respectively). Also, the purified antigens were able to raise polyclonal antibodies in animal models evoking a strong immune response with neutralizing activity in mice model. This research highlights the usefulness of antigens based on the non-N-glycosylated region of RBD from SARS-CoV-2 for candidate vaccine development.
【저자키워드】 SARS-CoV-2, Vaccine, Spike protein, Receptor binding domain, Prokaryotic expression, viral glycosylation, 【초록키워드】 neutralizing antibody, glycosylation, antibody, animal model, coronavirus 2, Antigen, Protein, serum, Neutralizing activity, IgG antibody, Host immune response, mice, RBD, sera, S-RBD, Research, Patient, respiratory, COVID-19 patients, Hypothesis, Escherichia coli, polyclonal antibody, residue, candidate vaccine, strong immune response, controls, limit, immunized, highlight, glycosylation site, raise, selected, determine, expressed, purified, glycosylated, the Spike, immunogenic potential, not carry, protein region, 【제목키워드】 COVID-19, Region, RBD, recombinant, candidate, Potential,