Identification of a novel B-cell epitope on the spike protein of porcine epidemic diarrhea virus

Abstract Porcine epidemic diarrhea virus (PEDV) is a highly pathogenic coronavirus that currently poses significant threats to the global swine industry. The spike (S) protein is the main PEDV structural protein that mediates viral entry while also serving as the major antigen that triggers host immune responses. To aid in the development of novel, advanced antiviral intervention strategies, identification of conserved epitopes within the fast-evolving S protein is essential. In the present study, we generated seven monoclonal antibodies (mAbs) against the S protein via the use of purified PEDV virions as immunogens, namely, 1F11, 2C4, 3D11, 3G7, 4G5, 8B2, and 8E4. Most of them were demonstrated to recognize conformational epitopes of the S protein, whereas only 4G5 was shown to recognize a linear epitope. To this end, a novel B-cell epitope, 1273 NATYLNLTGE 1282 , was identified and further shown to be highly conserved among different PEDV isolates. Taken together, our study contributes to a better understanding of PEDV S antigenicity, as the identification and validation of this conserved epitope will provide support for the development of serological diagnostic tools.