|Sosnovtsev, S - LID, NIAID, NIH|
|Green, K - LID, NIAID, NIH|
Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 10, 1998
Publication Date: N/A
Technical Abstract: Feline calicivirus (FCV) isolates can vary greatly antigenically. Two hypervariable regions identified in the capsid protein of FCV are proposed to form the antigenic determinants of the virus. To test this, the sequences encoding the hypervariable domains from the three antigenically distinct strains (CFI, KCD, and NADC) were exchanged with equivalent sequences in the URB strain infectious cDNA clone. Six viable chimeric viruses were recovered. Antisera raised against the four parental viruses confirmed that each strain was antigenically distinct. Neutralization analysis of the chimeric viruses showed that exchange of the hypervariable domains caused the loss of recognition by URB antisera. Parental serum in all but one case failed to recognize chimeric viruses. Transfer of NADC sequences caused elevated neutralization titers (NTs) by NADC antiserum but did not reach homologous levels. NTs of antisera raised against chimeric virus were low when tested against parental viruses but were elevated against all chimeric viruses, suggesting recognition of common elements. These data suggest that conformational epitopes are more important than linear in determining antigenicity in FCV.