title: Epitope-specific antibody responses to virulent and avirulent feline infectious peritonitis virus isolates.
abstract: Feline infectious peritonitis virus (FIPV) has been isolated several times from infected cats. Some of these isolates vary markedly in their ability to cause disease. Specific-pathogen-free cats were inoculated with the avirulent FIPV-UCD-2 isolate or the extremely virulent FIPV-79-1146 isolate or both. After 1 month, cats which had received FIPV-79-1146 were either dead or showed clinical signs of FIP. All cats which received only FIPV-UCD-2 remained healthy up to 6 months after inoculation. Antibody-mediated immune enhancement of disease was not observed in cats which received FIPV-UCD-2 before inoculation with FIPV-79-1146. Monoclonal antibodies which recognized type-specific epitopes on each of the structural polypeptides of these two viruses were used in competitive-inhibition enzyme-linked immunosorbent assays to analyze the humoral immune responses of the cats. All cats produced antibodies to epitopes found on the homologous virus. In addition, cats inoculated with FIPV-79-1146 also produced antibodies which inhibited the binding of the anti-FIPV-UCD-2 E1 monoclonal antibody. One cat inoculated twice with FIPV-UCD-2 produced antibodies which inhibited the binding of the anti-FIPV-79-1146 N- and E1-specific monoclonal antibodies. Competitive enzyme-linked immunosorbent assays may prove useful in distinguishing cats which are infected with virulent FIPV isolates from cats infected with avirulent feline coronaviruses.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology; D002371:Cat Diseases / Q000209:etiology / Q000276:immunology*; D002415:Cats; D003332:Coronaviridae / Q000276:immunology* / Q000472:pathogenicity; D003333:Coronaviridae Infections / Q000209:etiology / Q000276:immunology / Q000662:veterinary*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D010538:Peritonitis / Q000209:etiology / Q000276:immunology / Q000662:veterinary*; D013047:Specific Pathogen-Free Organisms; D014774:Virulence
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D007074:Immunoglobulin G