title: Immunogenicity Evaluation of Modified Adenovirus Vaccines Expressing Porcine Circovirus Type 2 Capsid Protein in Pigs.
abstract: Porcine circovirus type 2 (PCV2) adenovirus vaccine has been reported, but strong immune responses induced by adenovirus vector can decrease vaccine efficacy. To reduce the immunogenicity of adenovirus proteins, in previous study, we constructed the PCV2 adenovirus vaccine either modified with human cytomegalovirus first intron (Intron A) and woodchuck hepatitis virus post-transcriptional regulatory element (WPRE) to increase the expression of Cap, or coexpressed porcine tumor necrosis factor-related activate protein (CD40L) and granulocyte macrophage colony-stimulating factor (GMCSF) to improve the immunogenicity of PCV2 Cap adenovirus vaccine. All these vaccines were evaluated in mice. In the present study, the protective immune responses of Intron A/WPRE-modified recombinant adenovirus Ad-A-C-W and CD40L/GMCSF-modified recombinant adenovirus Ad-CD40L-Cap-GMCSF were evaluated in pigs. Enzyme-linked immunosorbent assay and virus neutralization assay showed that both Ad-A-C-W and Ad-CD40L-Cap-GMCSF could induce a higher specific antibody and neutralizing antibody than Ad-Cap (p < 0.05). Lymphocyte proliferation assay and cytokine release assay showed that Ad-A-C-W and Ad-CD40L-Cap-GMCSF induced a stronger cellular immune response than Ad-Cap. The PCV2 challenge experiment showed that viral loads of Ad-A-C-W-vaccinated group and Ad-CD40L-Cap-GMCSF-vaccinated group were lower than Ad-Cap vaccinated group (p < 0.05) after pigs were oronasally challenged with 5 × 105TCID50PCV2. Autopsy and histopathological examination showed that no obvious clinical and microscopic lesions were observed in groups Ad-Cap, Ad-A-C-W, and Ad-CD40L-Cap-GMCSF. Taken together, the results demonstrated that two modified recombinant adenovirus vaccines (Ad-A-C-W and Ad-CD40L-Cap-GMCSF) induced stronger humoral and cellular immune responses and provided better protection than unmodified adenovirus Ad-Cap. Therefore, Ad-A-C-W and Ad-CD40L-Cap-GMCSF would be used as potential vaccines for prevention and control of PCV2 infection.
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Delong
authors.initials: D
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xu
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Du
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Chang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: College of Veterinary Medicine, Northwest A&F University , Yangling, Shaanxi, People's Republic of China.
authors.forename: Dewen
authors.initials: D
authors.lastname: Tong
mesh_terms: D062705:Adenovirus Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D000276:Adjuvants, Immunologic / Q000235:genetics; D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D049109:Cell Proliferation; D018173:Circoviridae Infections / Q000276:immunology / Q000517:prevention & control*; D017925:Circovirus / Q000235:genetics / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D003587:Cytomegalovirus / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D017919:Hepatitis B Virus, Woodchuck / Q000235:genetics; D008214:Lymphocytes / Q000276:immunology; D009500:Neutralization Tests; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000517:prevention & control*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D062705:Adenovirus Vaccines; D000276:Adjuvants, Immunologic; D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D036022:Capsid Proteins; D016207:Cytokines; D014614:Vaccines, Synthetic
keywords: PCV2; adenovirus; immune responses; pigs