Abstract
Background: SARS-CoV-2 has spread worldwide causing more than 400 million people with virus infections since early 2020. Currently, the existing vaccines targeting the spike glycoprotein (S protein) of SARS-CoV-2 are facing great challenge from the infection of SARS-CoV-2 virus and its multiple S protein variants. Thus, we need to develop a new generation of vaccines to prevent infection of the SARS-CoV-2 variants. Compared with the S protein, the nucleocapsid protein (N protein) of SARS-CoV-2 is more conservative and less mutations, which also plays a vital role in viral infection. Therefore, the N protein may have the great potential for developing new vaccines.
Methods: The N protein of SARS-CoV-2 was recombinantly expressed and purified in Escherichia coli. Western Blot and ELISA assays were used to demonstrate the immunoreactivity of the recombinant N protein with the serum of 22 COVID-19 patients. We investigated further the response of the specific serum antibodies and cytokine production in BALB/c mice immunized with recombinant N protein by Western Blot and ELISA.
Results: The N protein had good immunoreactivity and the production of IgG antibody against N protein in COVID-19 patients was tightly correlated with disease severity. Furthermore, the N protein was used to immunize BALB/c mice to have elicited strong immune responses. Not only high levels of IgG antibody, but also cytokine-IFN-γ were produced in the N protein-immunized mice. Importantly, the N protein immunization induced a high level of IgM antibody produced in the mice.
Conclusion: SARS-CoV-2 N protein shows a great big bundle of potentiality for developing a new generation of vaccines in fighting infection of SARS-CoV-2 and its variants.
Keywords: SARS-CoV-2; antibody; immune response; nucleocapsid protein; vaccine.
【저자키워드】 SARS-CoV-2, immune response, antibody, nucleocapsid protein, vaccine., 【초록키워드】 viral infection, Vaccine, immune response, Vaccines, S protein, antibody, disease severity, mutations, spike glycoprotein, Infection, SARS-CoV-2 virus, cytokine, immunization, variants, ELISA, immune, nucleocapsid protein, Spread, Protein, serum, IgG antibody, Viral, SARS-CoV-2 variants, mice, nucleocapsid, western blot, immune responses, N protein, SARS-CoV-2 N protein, serum antibody, virus infection, virus infections, cytokine production, COVID-19 patients, ELISA assay, COVID-19 patient, Escherichia coli, specific serum, IgM antibody, immunoreactivity, serum antibodies, BALB/c mice, potentiality, ELISA assays, SARS-CoV-2 N, Prevent, immunized, Blot, produced, was used, develop, investigated, were used, less, in viral, expressed, correlated, the S protein, immunize, elicited, purified, the N protein, the SARS-CoV-2, 【제목키워드】 Vaccine, Protein,