title: Baculovirus expression of the N-terminus of porcine heat shock protein Gp96 improves the immunogenicity of recombinant PCV2 capsid protein.
abstract: Porcine circovirus type 2 (PCV2) causes significant economic losses to the swine industry worldwide. Heat shock proteins (Hsps) can be used as modulators to enhance both innate and adaptive immune responses. In the present study, recombinant baculoviruses expressing the PCV2Cap protein and the N-terminal 22-370 amino acids of porcine Gp96 (Gp96N), Hsp90, and Hsp70 (rBac-cap/Gp96N, rBac-cap/Hsp90 and rBac-cap/Hsp70, respectively) were constructed and the immune responses were examined in mice and piglets. The mouse experiments showed that rBac-cap/Gp96N increased the titers of specific anti-PCV2 neutralizing antibodies, proliferative responses of peripheral blood mononuclear cells (PBMCs) and IFN-γ levels compared to rBac-cap/Hsp90, rBac-cap/Hsp70, or rBac-cap. The pig experiments showed that the levels of anti-PCV2 antibody, proliferative responses of PBMCs, and IFN-γ in the rBac-cap/Gp96N groups were increased compared to those in rBac-cap group. There were no clear clinical signs of infection following PCV2 challenge in pigs inoculated with recombinant rBac-cap/Gp96N and rBac-cap, and the relative daily weight gains were higher than those in the challenge control (CC) group. The pathological lesions, extent of viremia, and viral loads of the vaccinated groups were milder than those in the CC group. Meanwhile, the extent of viremia and viral load present in the rBac-cap/Gp96N group were significantly lower than those in the rBac-cap group. These results indicated that porcine Gp96N effectively increased the humoral and cell-mediated immune responses of PCV2Cap. Gp96N presents an attractive adjuvant or immunotargeting strategy to enhance the protective efficacy of PCV2 subunit vaccines in swine.
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Bai
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Panrao
authors.initials: P
authors.lastname: Liu
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tingjie
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address: jiangp@njau.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: xwwang@njau.edu.cn.
authors.forename: Xianwei
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D016367:Baculoviridae; D036022:Capsid Proteins / Q000737:chemistry / Q000276:immunology*; D017925:Circovirus / Q000276:immunology*; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology*; D013552:Swine; D064166:Vaccine Potency; D022223:Vaccines, Subunit / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*; D014773:Virology / Q000379:methods
chemical_list: D036022:Capsid Proteins; D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; D022223:Vaccines, Subunit; D014765:Viral Vaccines
keywords: Baculoviruses; Gp96N; Hsps; PCV2Cap based vaccine