title: Humoral immune response of cats to virulent and avirulent feline infectious peritonitis virus isolates.
abstract: Isolates of feline infectious peritonitis virus (FIPV) vary in their degree of virulence and have antigenically and functionally different peplomer glycoproteins. We tested the most virulent isolate, FIPV-79-1146 and the avirulent isolate, FIPV-UCD-2 in vivo in order to better understand the pathogenesis of FIP. Specific pathogen free cats were inoculated with either FIPV-79-1146 or FIPV-UCD-2. After 28 days cats which had received FIPV-79-1146 were either dead or showing clinical signs of FIP. The FIPV-UCD-2 inoculated cats seroconverted but remained healthy and were then divided into three groups. One group was not manipulated, one group received a second dose of FIPV-UCD-2, and the third group received FIPV-79-1146. One month later all FIPV-UCD-2 cats which had subsequently received FIPV-79-1146 were dead of FIP while the FIPV-UCD-2 inoculated cats remained healthy. Antibody mediated immune enhancement of FIP disease was not observed. Serum neutralization assays demonstrated that only those cats which received FIPV-79-1146 developed neutralizing antibodies to FIPV-79-1146. However, all cats except uninoculated controls developed neutralizing titers to FIPV-UCD-2. Competition ELISAs were used to analyze the specific humoral immune responses of cats to structural polypeptides of the viruses.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000956:Antigens, Viral / Q000276:immunology; D002415:Cats; D003332:Coronaviridae / Q000276:immunology* / Q000302:isolation & purification / Q000472:pathogenicity; D003333:Coronaviridae Infections / Q000276:immunology*; D000939:Epitopes / Q000276:immunology; D009500:Neutralization Tests; D010538:Peritonitis / Q000276:immunology*; D013045:Species Specificity; D014764:Viral Proteins / Q000276:immunology; D015678:Viral Structural Proteins; D014774:Virulence
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D014764:Viral Proteins; D015678:Viral Structural Proteins