title: Enhancement of the immunogenicity of a porcine circovirus type 2 DNA vaccine by a recombinant plasmid coexpressing capsid protein and porcine interleukin-6 in mice.
abstract: The development of effective vaccines against porcine circovirus type 2 (PCV2) has been accepted as an important strategy in the prophylaxis of post-weaning multisystemic wasting syndrome; a DNA vaccine expressing the major immunogenic capsid (Cap) protein of PCV2 is considered to be a promising candidate. However, DNA vaccines usually induce weak immune responses. In this study, it was found that the efficacy of a DNA vaccine expressing Cap protein was improved by simultaneous expression of porcine IL-6. A plasmid (pIRES-ORF2/IL6) separately expressing both Cap protein and porcine IL-6 was constructed and compared with another plasmid (pIRES-ORF2) expressing Cap protein for its potential to induce PCV2-specific immune responses. Mice were vaccinated i.m. twice at 3 week intervals and the induced humoral and cellular responses evaluated. All animals vaccinated with pIRES-ORF2/IL6 and pIRES-ORF2 developed specific anti-PCV2 antibodies (according to enzyme-linked immunosorbent assay) and a T lymphocyte proliferation response. The percentages of CD3(+), CD3(+)CD8(+), and CD3(+)CD4(+) subgroups of peripheral blood T-lymphocytes were significantly higher in mice immunized with pIRES-ORF2/IL6 than in those that had received pIRES-ORF2. After challenge with the virulent PCV2 Wuzhi isolate, mice vaccinated with pIRES-ORF2/IL6 had significantly less viral replication than those vaccinated with pIRES-ORF2, suggesting that the protective immunity induced by pIRES-ORF2/IL6 is superior to that induced by pIRES-ORF2.
authors: College of Animal Science and Veterinary Medicine, Henan Agricultural University, 63 Nongye Road, Zhengzhou, 450002.
authors: Xiao-Qing
authors: XQ
authors: Guo
authors: Lin-Qing
authors: LQ
authors: Wang
authors: Han
authors: H
authors: Qiao
authors: Xing-Wu
authors: XW
authors: Yang
authors: Ming-Fan
authors: MF
authors: Yang
authors: Hong-Ying
authors: HY
authors: Chen
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D036022:Capsid Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D018173:Circoviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary* / Q000821:virology; D017925:Circovirus / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D005260:Female; D015850:Interleukin-6 / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D008297:Male; D051379:Mice; D009500:Neutralization Tests; D010957:Plasmids / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D013601:T-Lymphocytes / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins; D015850:Interleukin-6; D019444:Vaccines, DNA; D014765:Viral Vaccines
keywords: DNA vaccine; ORF2; porcine circovirus type 2; porcine interleukin-6