Comparison of the antibody response to transmissible gastroenteritis virus and porcine respiratory coronavirus, using monoclonal antibodies to antigenic sites A and X of the S glycoprotein.
Pigs were inoculated with various strains of transmissible gastroenteritis virus (TGEV) or with porcine respiratory coronavirus (PRCV), and antigenic site-specific antibody responses were compared. A blocking-ELISA was used to study to what extent antibodies in convalescent sera interfered with the binding of monoclonal antibodies (MAB) 57.16 or 57.110 to the attenuated TGEV/Purdue virus. Monoclonal antibody 57.16 is directed against the A site on the peplomer, neutralizes virus, and recognizes TGEV and PRCV. Monoclonal antibody 57.110 is directed against the X site on the peplomer, but does not neutralize virus, and recognizes only TGEV. Antibodies directed against TGEV and PRCV could be detected in a blocking ELISA, using MAB 57.16 as a conjugate. Antibodies directed against both viruses were detectable as early as 1 week after inoculation. Antibody titers correlated well with those in a virus-neutralization test. Antibodies against TGEV could be detected in a blocking ELISA, using MAB 57.110 as a conjugate. Such antibodies were not induced by a PRCV infection. In the blocking ELISA, using MAB 57.110 as a conjugate, antibodies were detectable as early as 2 weeks after inoculation. There was a significant difference between antibody titers reached after infection with various TGEV strains, however. This difference is ascribed to a variation of the antigenic site defined by MAB 57.110 in TGEV strains. Conditions for a differential test for TGE serodiagnosis, and for serologic discrimination between TGEV- and PRCV-infected pigs, are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)
van Nieuwstadt
A P
AP
Central Veterinary Institute, AJ Lelystad, The Netherlands.
Boonstra
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000956:Antigens, Viral / Q000276:immunology; D001667:Binding, Competitive; D003332:Coronaviridae / Q000276:immunology*; D003333:Coronaviridae Infections / Q000276:immunology / Q000662:veterinary; D004797:Enzyme-Linked Immunosorbent Assay; D005761:Gastroenteritis, Transmissible, of Swine / Q000276:immunology; D005856:Germ-Free Life; D006023:Glycoproteins / Q000276:immunology; D007106:Immune Sera / Q000276:immunology; D012141:Respiratory Tract Infections / Q000276:immunology / Q000662:veterinary; D013047:Specific Pathogen-Free Organisms; D013552:Swine; D013553:Swine Diseases / Q000276:immunology; D005760:Transmissible gastroenteritis virus / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D006023:Glycoproteins; D007106:Immune Sera