Publication date: Sep 17, 2025
The N-terminal S1 subunit of the spike protein (S1 protein) of porcine epidemic diarrhea virus (PEDV) is recognized as a potential diagnostic antigen for detecting anti-PEDV immunoglobulin A (IgA) levels in colostrum, a key indicator for assessing passive immunity against PEDV infection. Given the advantages of producing Fc-fusion proteins in mammalian cells, it is important to investigate how the addition of the Fc region affects the diagnostic performance of the PEDV-S1 protein. In this study, we successfully produced full-length PEDV-S1 protein fused with an Fc region (PEDV-S1-Fc protein) via transient gene expression in recombinant Chinese hamster ovary (rCHO) cells adapted to serum-free suspension culture. The resulting expression showed significantly higher volumetric productivity than previously reported. The aglycosylated form of PEDV-S1-Fc protein was also generated using PNGase F treatment of the purified protein, as well as tunicamycin treatment to inhibit glycosylation during cell culture. Notably, neither the addition of the Fc region nor the removal of N-glycans markedly affected the diagnostic function, as demonstrated by indirect ELISA using PEDV-positive and PEDV-negative colostrum samples. Moreover, the diagnostic performance of the PEDV-S1-Fc protein was further validated using total IgA purified from PEDV-positive colostrum. In summary, the full-length Fc-fused PEDV-S1 protein produced in rCHO cell culture exhibited high productivity and purity, making it a promising antigenic candidate for indirect ELISA-based detection of anti-PEDV IgA in colostrum.

Semantics
| Type | Source | Name |
|---|---|---|
| disease | IDO | production |
| disease | IDO | protein |
| disease | MESH | infection |
| drug | DRUGBANK | Tunicamycin |
| disease | IDO | cell |
| disease | MESH | Coronavirus Infections |
| disease | IDO | assay |
| disease | MESH | Swine Diseases |