ARS | Publication request: STRUCTURE/FUNCTION STUDIES OF THE CAPSID PROTEIN OF CALICIVIRUSES: DOMAIN SWAPS BETWEEN DIFFERENT FELINE CALICIVIRUS STRAINS

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: September 17, 1996
Publication Date: N/A

Technical Abstract: Little is known concerning the function(s) of specific calicivirus protein and the domains within these proteins. This is especially true of the single capsid protein. The capsid protein of the animal caliciviruses has been divided into 6 distinct regions (A-F) based on the degree of conservation of the amino acid sequences among feline calicivirus (FCV), San Miguel sea lion virus, and rabbit hemorrhagic disease virus isolates. To examine the function of the hypervariable E region, sequences encoding the E region from the FCV strains CFI and NADC were used to replace the homologous sequences in the FCV Urbana infectious clone. This resulted in constructs consisting of the Urbana genomic sequences with 334 bp exchanged in the E region-encoding sequences near the 3' end of the genome. Virus was recovered from the NADC/Urbana construct (UN), while the CFI/Urbana construct was apparently nonviable. Serum cross-neutralization analysis of fthe parental Urbana and NADC strains and the recombinant UN demonstrates that antigenic recognition by antisera against the parental strains was greatly altered by the exchange of the E region in the UN recombinant. The UN recombinant showed a 126-fold decrease in neutralization with Urbana antiserum and a 256-fold increase in neutralization with antiserum against NADC. This demonstrates a reversal in neutralization with the exchange of the E region. These data indicate that the capsid protein E region plays a major role in antigenic variation in feline calicivirus.