Recombinant expression of SARS-CoV-۲ Receptor Binding Domain (RBD) in Escherichia coli and its immunogenicity in mice

Objective(s): The severe acute respiratory syndrome coronavirus-۲ (SARS-CoV-۲), giving rise to the coronavirus disease ۲۰۱۹ (COVID-۱۹), has become a danger to wellbeing worldwide. Thus, finding efficient and safe vaccines for COVID-۱۹ is of great importance. As a basic step amid contamination, SARS-CoV-۲ employs the receptor-binding domain (RBD) of the spike protein to lock in with the receptor angiotensin-converting enzyme ۲ (ACE۲) on host cells. SARS-CoV-۲ receptor-binding domain (RBD) is the main human antibody target for developing vaccines and virus inhibitors, as well as neutralizing antibodies. A bacterial procedure was developed for the expression and purification of the SARS-CoV-۲ spike protein receptor-binding domain.Materials and Methods: In this research study, RBD was expressed by Escherichia coli and purified with Ni-NTA chromatography. Then it was affirmed by the western blot test. The immunogenicity and protective efficacy of RBD recombinant protein were assessed on BALB/c mice. Additionally, RBD recombinant protein was tested by ELISA utilizing sera of COVID-۱۹ healing patients contaminated with SARS-CoV-۲ wild type and Delta variation. Results: Indirect ELISA was able to detect the protein RBD in serum of the immunized mouse expressed in E. coli. The inactive SARS-CoV۲ was detected by antibodies within the serum of immunized mice. Serum antibodies from individuals recovered from Covid۱۹ reacted to the expressed protein.Conclusion: Our findings showed that RBD is of great importance in vaccine design and it can be used to develop recombinant vaccines through induction of antibodies against RBD.

Keywords:

Neutralizing antibodies , RBD , Recombinant proteins , SARS-CoV-۲ , Vaccines