Porcine epidemic diarrhea virus (PEDV) is a highly infectious pathogen of watery diarrhea that causes serious economic loss to the swine industry worldwide. Especially because of the high mortality rate in neonatal piglets, a vaccine with less production cost and high protective effect against PEDV is desired. The intrinsically assembled homotrimer of spike (S) protein on the PEDV viral membrane contributing to the host cell entry is a target of vaccine development. In this study, we designed trimerized PEDV S protein for efficient production in the silkworm-baculovirus expression vector system (silkworm-BEVS) and evaluated its immunogenicity in the mouse. The genetic fusion of the trimeric motif improved the expression of S protein in silkworm-BEVS. A small-scale screening of silkworm strains to further improve the S protein productivity finally achieved the yield of about 2 mg from the 10 mL larval serum. Mouse immunization study demonstrated that the trimerized S protein could elicit strong humoral immunity, including the S protein-specific IgG in the serum. These sera contained neutralizing antibodies that can protect Vero cells from PEDV infection. These results demonstrated that silkworm-BEVS provides a platform for the production of trimeric S proteins, which are promising subunit vaccines against coronaviruses such as PEDV. Supplementary Information The online version contains supplementary material available at 10.1186/s13567-021-00971-5.
【저자키워드】 Spike protein, Subunit vaccine, Silkworm-baculovirus expression vector system, Porcine epidemic diarrhea virus, trimeric motif, 【초록키워드】 neutralizing antibody, IgG, Vaccine, Vaccine development, coronavirus, S protein, Genetic, Infection, diarrhea, virus, immunization, Protein, serum, Humoral immunity, pathogen, sera, mouse, expression, platform, protective effect, strain, Neonatal, host cell, economic loss, epidemic diarrhea, supplementary material, viral membrane, S proteins, PEDV, high mortality rate, motif, expression vector, Vero Cell, trimeric, IMPROVE, PROTECT, evaluated, provide, less, demonstrated, elicit, cause, contributing to, the S protein, watery, intrinsically, homotrimer, 【제목키워드】 neutralizing antibody, virus, mice, Efficiency, epidemic diarrhea, trimer, STABLE, IMPROVE, induce,