Establishment of Immunochromatographic Test Strips for Porcine Epidemic Diarrhea Virus (PEDV) Antibody Detection Based on Monoclonal Antibodies Against S2 Protein

Porcine epidemic diarrhea (PED) is an acute infectious disease caused by the porcine epidemic diarrhea virus (PEDV). Clinical manifestations include severe diarrhea, vomiting, dehydration and even death in piglets, causing significant economic losses to the global pig farming industry. Reliable on-site diagnostic tools for early PEDV detection, particularly for emerging variants, remain scarce. The spike (S) protein plays a critical role during the viral entry process, and its S2 subunit exhibits high conservation among different PEDV strains. In this study, a recombinant pColdI-S2 protein was expressed and purified. Following mouse immunization, cell fusion, and screening, two monoclonal antibodies (mAbs) targeting distinct conserved epitopes of the S2 protein were generated using hybridoma technology. The recombinant S2 protein was then conjugated with Prussian blue nanoparticles (PBNPs) to serve as a detector reagent. Staphylococcal protein A (SPA) and the anti-S2 mAb were immobilized on the test (T) line and control (C) line of the strip, respectively. Based on these components, an immunochromatographic strip was preliminarily established for detecting antibodies specific to the S2 protein of PEDV. Our findings demonstrate the potential of this assay as a reliable tool for serological surveillance of PEDV infection in swine populations, facilitate rapid clinical diagnosis and contribute to PED control strategies.