title: A novel vaccine against Porcine circovirus type 2 (PCV2) and Streptococcus equi ssp. zooepidemicus (SEZ) co-infection.
abstract: To develop a vaccine against Porcine circovirus type 2 (PCV2) and Streptococcus equi ssp. zooepidemicus (SEZ) co-infection, the genes of porcine IL-18, capsid protein (Cap) of PCV2 and M-like protein (SzP) of SEZ were inserted into the swinepox virus (SPV) genome by homologous recombination. The recombinant swinepox virus rSPV-ICS was verified by PCR and indirect immunofluorescence assays. To evaluate the immunogenicity of rSPV-ICS, 28 PCV2 and SEZ seronegative Bama minipigs were immunized with rSPV-ICS (n=8), commercial PCV2 vaccine and SEZ vaccine (n=8) or wild type SPV (n=8). The results showed that SzP-specific antibody and PCV2 neutralizing antibody of the rSPV-ICS immunized group increased significantly compared to the wild type SPV treated group after vaccination and increased continuously over time. The levels of IL-4 and IFN-γ in the rSPV-ICS immunized group were significantly higher than the other three groups, respectively. After been co-challenged with PCV2 and SEZ, 87.5% piglets in rSPV-ICS immunized group were survived. Significant reductions in gross lung lesion score, histopathological lung lesion score, and lymph node lesion score were noticed in the rSPV-ICS immunized group compared with the wtSPV treated group. The results suggested that the recombinant rSPV-ICS provided piglets with significant protection against PCV2-SEZ co-infection; thus, it offers proof-of-principle for the development of a vaccine for the prevention of these swine diseases.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Hui-xing
authors.initials: HX
authors.lastname: Lin
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Ma
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Xu-qiu
authors.initials: XQ
authors.lastname: Yang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address: fhj@njau.edu.cn.
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Fan
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Cheng-ping
authors.initials: CP
authors.lastname: Lu
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology / Q000592:standards; D018173:Circoviridae Infections / Q000150:complications / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D017925:Circovirus / Q000235:genetics / Q000276:immunology; D060085:Coinfection; D007114:Immunization / Q000662:veterinary*; D013290:Streptococcal Infections / Q000150:complications / Q000473:pathology / Q000517:prevention & control / Q000662:veterinary*; D018502:Streptococcus equi / Q000235:genetics / Q000276:immunology; D018148:Suipoxvirus / Q000235:genetics; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control*; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000235:genetics; D014765:Viral Vaccines / Q000276:immunology / Q000592:standards
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D014614:Vaccines, Synthetic; D014764:Viral Proteins; D014765:Viral Vaccines
keywords: Porcine circovirus type 2; Recombinant swinepox virus; Streptococcus equi ssp. zooepidemicus; Vaccine