title: An ELISA for detection of antibodies against porcine epidemic diarrhoea virus (PEDV) based on the specific solubility of the viral surface glycoprotein.
abstract: Viral proteins of porcine epidemic diarrhoea virus (PEDV) were extracted from the cytoplasm of infected Vero cells using hypotonic conditions and a non-ionic detergent. Both the pH and the NaCl concentration of the extraction buffer were varied in attempts to increase the solubility of the virion spike glycoproteins (S-protein) and of the nucleocapsid proteins (N-protein). Monoclonal antibodies, hyperimmune sera and convalescent pig sera were used to identify and monitor these proteins by immunoprecipitation and Western blots. The solubility of the S-protein was optimal at pH 4, whereas that of the N-protein was optimal at pH 9. Consequently, it was possible to enrich for either S-protein or N-protein; increases in the NaCl concentration of the buffer were of no advantage in this respect. Enriched preparations of the S-protein and N-protein were used as ELISA antigen for the S-ELISA and N-ELISA, respectively. The S-ELISA proved to be the more effective of the two immunoassays. Antibodies against S-protein remained detectable for longer periods of time than anti-N-protein antibodies in the sera of PEDV-infected pigs. Using this ELISA of increased sensitivity, it was observed that only a small number of farms in Switzerland had been infected with PEDV.
authors.affiliation: Institut für Virologie, Vet.-med. Fakultät, Universität Zürich, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Knuchel
authors.forename: M
authors.initials: M
authors.lastname: Ackermann
authors.forename: H K
authors.initials: HK
authors.lastname: Müller
authors.forename: U
authors.initials: U
authors.lastname: Kihm
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000737:chemistry / Q000276:immunology; D002213:Capsid / Q000737:chemistry / Q000276:immunology; D003332:Coronaviridae / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006023:Glycoproteins / Q000737:chemistry / Q000276:immunology*; D006863:Hydrogen-Ion Concentration; D015151:Immunoblotting; D008970:Molecular Weight; D012995:Solubility; D013552:Swine; D014709:Vero Cells; D014758:Viral Core Proteins / Q000737:chemistry / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D006023:Glycoproteins; D014758:Viral Core Proteins; D014764:Viral Proteins; C064484:spike protein S, Transmissible gastroenteritis virus