The Middle East respiratory syndrome coronavirus (MERS-CoV), belonging to the family Coronaviridae and genus Betacoronavirus , has been recognized as a highly pathogenic virus. Due to the lack of therapeutic or preventive agents against MERS-CoV, developing an effective vaccine is essential for preventing a viral outbreak. To address this, we developed a recombinant S1 subunit of MERS-CoV spike protein fused with the human IgG4 Fc fragment (LV-MS1-Fc) in Chinese hamster ovary (CHO) cells. Thereafter, we identified the baculovirus gp64 signal peptide-directed secretion of LV-MS1-Fc protein in the extracellular fluid. To demonstrate the immunogenicity of the recombinant LV-MS1-Fc proteins, BALB/c mice were inoculated with 2.5 μg of LV-MS1-Fc. The inoculated mice demonstrated a significant humoral immune response, measured via total IgG and neutralizing antibodies. In addition, human dipeptidyl peptidase-4 (DPP4) transgenic mice vaccinated with LV-MS1-Fc showed the protective capacity of LV-MS1-Fc against MERS-CoV with no inflammatory cell infiltration. These data showed that the S1 and Fc fusion protein induced potent humoral immunity and antigen-specific neutralizing antibodies in mice, and conferred protection against coronavirus viral challenge, indicating that LV-MS1-Fc is an effective vaccine candidate against MERS-CoV infection.
【저자키워드】 Vaccine development, immunogenicity, RBD, receptor-binding domain, Middle East respiratory syndrome Coronavirus, SARS-CoV, severe acute respiratory syndrome coronavirus, ELISA, enzyme-linked immunosorbent assay, MERS-CoV, Middle East respiratory syndrome coronavirus, MERS, Middle East respiratory syndrome, PCR, polymerase chain reaction, alum adjuvant, PBS, phosphate-buffered saline, PFU, plaque-forming unit, BSL, biosafety level, CEF, chicken embryo fibroblast, CHO, Chinese hamster ovary, Fc, fragment of crystalline, PBST, phosphate-buffered saline in 0.05 % Tween 20, RLU, relative light unit, SFM, serum-free medium, Fragment of crystalline (Fc) molecule, 【초록키워드】 IgG, Vaccine, coronavirus, Neutralizing antibodies, Proteins, virus, MERS-CoV, Spike protein, DPP4, Dipeptidyl peptidase-4, Protein, Humoral immunity, cells, mice, therapeutic, vaccine candidate, humoral immune response, fusion protein, baculovirus, Protective, S1 subunit, viral challenge, Middle East, IgG4, Fc fragment, Chinese hamster, secretion, transgenic mice, family Coronaviridae, respiratory syndrome coronavirus, BALB/c mice, MERS-CoV infection, viral outbreak, inflammatory cell infiltration, highly pathogenic, effective, genus Betacoronavirus, Extracellular, lack, inoculated, addition, demonstrated, fused, antigen-specific neutralizing antibody, 【제목키워드】 Vaccine, MERS-CoV, fusion protein, development, transgenic mice, human DPP4,