Fine mapping of antigenic epitopes on capsid proteins of porcine circovirus, and antigenic phenotype of porcine circovirus type 2.
Type 2 porcine circovirus (PCV2) is associated with post-weaning multisystemic wasting syndrome in pigs. In this study, three monoclonal antibodies (mAbs) against the capsid protein (Cap) of PCV2, eight mAbs to Cap of type 1 porcine circovirus (PCV1) and five mAbs specific for Cap of both PCV1 and PCV2, were generated and used to finely map the antigenic sites of PCV1 and PCV2, and to identify the antigenic phenotype of PCV2 with different length of genome. Five linear B-cell epitopes, including the residues 231-233 and 195-202 specific for PCV2, residues 92-103 specific for PCV1, and residues 156-162 and 175-192 shared between PCV1 and PCV2, were finely defined with synthetic peptides, and the critical residue in epitope 231-233 and 156-162 was located at residues 233 ((233)Proline) and 156 ((156)Tyrosine), respectively. The conformational epitopes recognized by mAbs with neutralizing activity against both PCV1 and PCV2 were detected in transfected PK-15 and the residues 231-233 also participated in the formation of conformational epitopes. Analysis of antigenic diversity on these epitopes exhibited three antigenic phenotypes of PCV2, (1766)PCV2, (1767)PCV2 and (1768)PCV2 using mAbs. The results from this study first demonstrated the different antigenic phenotype between PCV2 isolates.
Shang
Shao-Bin
SB
Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, Zhejiang University, Hangzhou 310029, PR China.
Jin
Yu-Lan
YL
Jiang
Xue-tao
XT
Zhou
Ji-Yong
JY
Zhang
Xin
X
Xing
Gang
G
He
Jia Ling
JL
Yan
Yan
Y
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000917:Antibody Formation; D000956:Antigens, Viral / Q000737:chemistry / Q000276:immunology*; D036022:Capsid Proteins / Q000737:chemistry* / Q000276:immunology*; D002460:Cell Line; D018173:Circoviridae Infections / Q000276:immunology; D017925:Circovirus / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D004797:Enzyme-Linked Immunosorbent Assay; D018604:Epitope Mapping; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D016678:Genome; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D010641:Phenotype; D011487:Protein Conformation; D034421:Sus scrofa; D014162:Transfection
D000911:Antibodies, Monoclonal; D000956:Antigens, Viral; D036022:Capsid Proteins; D000939:Epitopes