title: Reactivity of Porcine Epidemic Diarrhea Virus Structural Proteins to Antibodies against Porcine Enteric Coronaviruses: Diagnostic Implications.
abstract: The development of porcine epidemic diarrhea virus (PEDV) antibody-based assays is important for detecting infected animals, confirming previous virus exposure, and monitoring sow herd immunity. However, the potential cross-reactivity among porcine coronaviruses is a major concern for the development of pathogen-specific assays. In this study, we used serum samples (n= 792) from pigs of precisely known infection status and a multiplex fluorescent microbead-based immunoassay and/or enzyme-linked immunoassay platform to characterize the antibody response to PEDV whole-virus (WV) particles and recombinant polypeptides derived from the four PEDV structural proteins, i.e., spike (S), nucleocapsid (N), membrane (M), and envelope (E). Antibody assay cutoff values were selected to provide 100% diagnostic specificity for each target. The earliest IgG antibody response, mainly directed against S1 polypeptides, was observed at days 7 to 10 postinfection. With the exception of nonreactive protein E, we observed similar antibody ontogenies and patterns of seroconversion for S1, N, M, and WV antigens. Recombinant S1 provided the best diagnostic sensitivity, regardless of the PEDV strain, with no cross-reactivity detected against transmissible gastroenteritis virus (TGEV), porcine respiratory coronavirus (PRCV), or porcine deltacoronavirus (PDCoV) pig antisera. The WV particles showed some cross-reactivity to TGEV Miller and TGEV Purdue antisera, while N protein presented some cross-reactivity to TGEV Miller. The M protein was highly cross-reactive to TGEV and PRCV antisera. Differences in the antibody responses to specific PEDV structural proteins have important implications in the development and performance of antibody assays for the diagnosis of PEDV enteric disease.
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA luisggl@iastate.edu.
authors.forename: Luis Gabriel
authors.initials: LG
authors.lastname: Gimenez-Lirola
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Departamento de Microbiología, Facultad de Medicina, Universidad de Granada-ibs, Granada, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Carrillo-Avila
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Magtoto
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Korakrit
authors.initials: K
authors.lastname: Poonsuk
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: David H
authors.initials: DH
authors.lastname: Baum
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Pablo
authors.initials: P
authors.lastname: Piñeyro
authors.affiliation: College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Zimmerman
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D000956:Antigens, Viral / Q000276:immunology*; D018352:Coronavirus Infections / Q000175:diagnosis / Q000662:veterinary / Q000821:virology; D000086862:Coronavirus M Proteins; D000086462:Coronavirus Nucleocapsid Proteins; D003429:Cross Reactions / Q000276:immunology; D003937:Diagnosis, Differential; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D019590:Nucleocapsid Proteins / Q000276:immunology; D053485:Porcine epidemic diarrhea virus / Q000276:immunology*; D013552:Swine / Q000821:virology*; D013553:Swine Diseases / Q000175:diagnosis* / Q000821:virology; D005760:Transmissible gastroenteritis virus / Q000276:immunology*; D014763:Viral Matrix Proteins / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000086862:Coronavirus M Proteins; D000086462:Coronavirus Nucleocapsid Proteins; D007074:Immunoglobulin G; C000706236:M protein, Porcine epidemic diarrhea virus; C000706238:M protein, Transmissible gastroenteritis virus; D019590:Nucleocapsid Proteins; D014763:Viral Matrix Proteins
keywords: ELISA; PEDV; antibody response; cross-reactivity; multiplex FMIA; recombinant structural proteins; whole virus