Oral administration of porcine epidemic diarrhea virus spike protein expressing in silkworm pupae failed to elicit immune responses in pigs
Journal
AMB Express
Journal Volume
10
Journal Issue
1
Date Issued
2020
Author(s)
Abstract
The silkworm (Bombyx mori) and its pupae have been used for decades as nutritional additives and applied on the production of high-quality recombinant proteins via the baculovirus expression vector (BEV) system. The bio-capsule, the fat-rich body, and some body components of the silkworm pupae, which deliver antigens passing through the harsh environment of digestive tract and reaching the intestine, have been used as a vehicle for oral vaccines. In the present study, to develop a novel oral vaccine against porcine epidemic diarrhea virus (PEDV), the PEDV spike (S) protein was expressed in silkworm pupae and BmN cells using the BEV system. After three doses of oral administrations with 2-week intervals in pigs, neither PEDV S protein-specific humoral nor mucosal immune responses can be detected. The failure of eliciting the PEDV-specific immune response suggested that the BEV system using BmN cells or silkworm pupae as oral immunogen-expression vehicles was not able to overcome the immunological unresponsiveness, which was?possibly due to gastrointestinal specific barriers?and oral tolerance. Better strategies to enhance the delivery and immunogenicity of oral vaccines should be further investigated. Nevertheless, the PEDV S protein generated in the BmN cells and silkworm pupae herein provides an efficient tool to produce the recombinant antigen for future applications. ? 2020, The Author(s).
Subjects
Baculovirus expression vector system (BEVS); Oral vaccine; Porcine epidemic diarrhea virus (PEDV); Silkworm pupae (Bombyx mori); Spike protein
SDGs
Other Subjects
heat shock protein 70; immunoglobulin A; immunoglobulin G; immunoglobulin M; tumor necrosis factor; virus spike protein; vitronectin; animal cell; animal experiment; animal tissue; antibody response; antibody titer; Article; blood sampling; Bombyx mori; controlled study; enzyme linked immunosorbent assay; epidemic; gene sequence; genetic transfection; immune response; immunization; immunofluorescence test; immunogenicity; ion exchange chromatography; nonhuman; polyacrylamide gel electrophoresis; Porcine epidemic diarrhea virus; promoter region; protein expression; protein synthesis; pupa; tissue culture; vaccination; virus load; Western blotting
Type
journal article