title: Immune responses of piglets immunized by a recombinant plasmid containing porcine circovirus type 2 and porcine interleukin-18 genes.
abstract: In this study, two recombinant plasmids containing the ORF2 gene of porcine circovirus type 2 (PCV2) with or without porcine interleukin-18 (IL-18) were constructed and evaluated for their ability to protect piglets against PCV2 challenge. Transient expression of the plasmids in PK-15 cells could be detected using Western blot. Piglets were given two intramuscular immunizations 3 weeks apart and were challenged with a virulent Wuzhi strain of PCV2 at 42 days after the initial immunization. All animals vaccinated with pBudCE4.1-ORF2 or with pBudCE4.1-ORF2/IL18 developed PCV2-specific antibody and T-lymphocyte proliferative responses. The levels of T-lymphocyte proliferation in piglets immunized with pBudCE4.1-ORF2/IL18 were significantly higher than in those immunized with pBudCE4.1-ORF2, and pBudCE4.1-ORF2/IL18 stimulated a significantly increased production of IFN-γ and IL-2. Furthermore, PCV2 challenge experiments showed that the DNA vaccine-immunized groups can partially prevent PCV2 viremia and significantly reduce the amount of PCV2 virus in the lymphoid tissues, and the piglets immunized by pBudCE4.1-ORF2/IL18 exhibit a marked inhibition of PCV2 replication compared to the pBudCE4.1-ORF2 group. These data demonstrate that the plasmid pBudCE4.1-ORF2/IL18 may be an effective approach for increasing PCV2 DNA vaccine immunogenicity.
authors.affiliation: 1 College of Animal Science and Veterinary Medicine, Henan Agricultural University , Zhengzhou, Henan Province, People's Republic of China .
authors.forename: Guang-Lei
authors.initials: GL
authors.lastname: Chen
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Fu
authors.forename: Lin-Qing
authors.initials: LQ
authors.lastname: Wang
authors.forename: Xin-Sheng
authors.initials: XS
authors.lastname: Li
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Chen
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000235:genetics; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D049109:Cell Proliferation; D018173:Circoviridae Infections / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D017925:Circovirus / Q000235:genetics / Q000276:immunology*; D007273:Injections, Intramuscular; D007371:Interferon-gamma / Q000378:metabolism; D020382:Interleukin-18 / Q000008:administration & dosage* / Q000235:genetics; D007376:Interleukin-2 / Q000378:metabolism; D008221:Lymphoid Tissue / Q000821:virology; D016366:Open Reading Frames; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control*; D013601:T-Lymphocytes / Q000276:immunology; D014611:Vaccination / Q000379:methods; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D019562:Viral Load; D014764:Viral Proteins / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014766:Viremia / Q000517:prevention & control; D014779:Virus Replication
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D020382:Interleukin-18; D007376:Interleukin-2; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D014764:Viral Proteins; D014765:Viral Vaccines; D007371:Interferon-gamma