title: Immune responses of chickens inoculated with a recombinant fowlpox vaccine coexpressing HA of H9N2 avain influenza virus and chicken IL-18.
abstract: Control of the circulation of H9N2 avian influenza virus (AIV) is a major concern for both animal and public health, and H9N2 AIV poses a major threat to the chicken industry worldwide. Here, we developed a recombinant fowlpox virus (rFPV-HA) expressing the haemagglutinin (HA) gene of the A/CH/JY/1/05 (H9N2) influenza virus and a recombinant fowlpox virus (rFPV-HA/IL18) expressing the HA gene and chicken interleukin-18 (IL-18) gene. Recombinant plasmid pSY-HA/IL18 was constructed by cloning chicken IL-18 expression cassette into recombinant plasmid pSY-HA containing the HA gene. Two rFPVs were generated by transfecting two recombinant plasmids into the chicken embryo fibroblast cells pre-infected with S-FPV-017, and assessed for their immunological efficacy on one-day-old White Leghorn specific-pathogen-free chickens challenged with the A/CH/JY/1/05 (H9N2) strain. There was a significant difference in HI antibody levels (P<0.05) elicited by either rFPV-HA or rFPV-HA/IL18. The level of splenocyte proliferation response in the rFPV-HA/IL18-vaccinated group was significantly higher (P<0.05) than that in the rFPV-HA group. After challenge with 10(6.5)ELD(50) H9N2 AIV 43days after immunization, rFPVs vaccinated groups could prevent virus shedding and replication in multiple organs in response to H9N2 AIV infection, and rFPV-HA/IL18 vaccinated group had better inhibition of viruses than rFPV-HA vaccinated group. Our results show that the protective efficacy of the rFPV-HA vaccine could be enhanced significantly by simultaneous expression of IL-18.
authors.affiliation: College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan Province, People's Republic of China.
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Chen
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Shang
authors.forename: Hui-Xia
authors.initials: HX
authors.lastname: Yao
authors.forename: Bao-An
authors.initials: BA
authors.lastname: Cui
authors.forename: Hong-Ying
authors.initials: HY
authors.lastname: Zhang
authors.forename: Zi-Xin
authors.initials: ZX
authors.lastname: Wang
authors.forename: Ya-Dan
authors.initials: YD
authors.lastname: Wang
authors.forename: An-Jun
authors.initials: AJ
authors.lastname: Chao
authors.forename: Ting-Yun
authors.initials: TY
authors.lastname: Duan
mesh_terms: D000818:Animals; D000914:Antibodies, Viral; D002478:Cells, Cultured; D002642:Chick Embryo; D002645:Chickens / Q000276:immunology; D005586:Fowlpox / Q000276:immunology* / Q000517:prevention & control; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics* / Q000276:immunology*; D005585:Influenza in Birds / Q000235:genetics / Q000276:immunology* / Q000517:prevention & control; D020382:Interleukin-18 / Q000276:immunology*; D012320:RNA Polymerase III; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D020382:Interleukin-18; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; D012320:RNA Polymerase III