Antigenic differences among porcine circovirus type 2 strains, as demonstrated by the use of monoclonal antibodies.
This study examined whether antigenic differences among porcine circovirus type 2 (PCV-2) strains could be detected using monoclonal antibodies (mAbs). A subtractive immunization protocol was used for the genotype 2 post-weaning multisystemic wasting syndrome (PMWS)-associated PCV-2 strain Stoon-1,010. Sixteen stable hybridomas that produced mAbs with an immunoperoxidase monolayer assay (IPMA) titre of 1,000 or more to Stoon-1,010 were obtained. Staining of recombinant PCV-2 virus-like particles demonstrated that all mAbs were directed against the PCV-2 capsid protein. Cross-reactivity of mAbs was tested by IPMA and neutralization assay for genotype 1 strains 48,285, 1,206, VC2,002 and 1,147, and genotype 2 strains 1,121 and 1,103. Eleven mAbs (9C3, 16G12, 21C12, 38C1, 43E10, 55B1, 63H3, 70A7, 94H8, 103H7 and 114C8) recognized all strains in the IPMA and demonstrated neutralization of Stoon-1,010, 48,285, 1,206 and 1,103, but not VC2,002, 1,147 and 1,121. mAbs 31D5, 48B5, 59C6 and 108E8 did not react with genotype 1 strains or had a reduced affinity compared with genotype 2 strains in the IPMA and neutralization assay. mAb 13H4 reacted in the IPMA with PMWS-associated strains Stoon-1,010, 48,285, 1,206 and VC2,002, and the porcine dermatitis and nephropathy syndrome-associated strain 1,147, but not with reproductive failure-associated strains 1,121 and 1,103. mAb 13H4 did not neutralize any of the tested strains. It was concluded that, despite the high amino acid identity of the capsid protein (>or=91 %), antigenic differences at the capsid protein level are present among PCV-2 strains with a different genetic and clinical background.
Lefebvre
D J
DJ
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Costers
S
S
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Van Doorsselaere
J
J
Department of Health Care and Biotechnology, KATHO Catholic University College of South-West Flanders, Wilgenstraat 32, 8800 Roeselare, Belgium.
Misinzo
G
G
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Delputte
P L
PL
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
Nauwynck
H J
HJ
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000276:immunology; D000940:Antigenic Variation / Q000235:genetics*; D002460:Cell Line; D017925:Circovirus / Q000145:classification / Q000235:genetics*; D017124:Conserved Sequence; D017931:DNA Primers; D005838:Genotype; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D016366:Open Reading Frames; D010802:Phylogeny; D012680:Sensitivity and Specificity; D016415:Sequence Alignment; D013552:Swine
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D017931:DNA Primers