title: Enhanced immunity against classical swine fever in pigs induced by prime-boost immunization using an alphavirus replicon-vectored DNA vaccine and a recombinant adenovirus.
abstract: Classical swine fever (CSF) - caused by the classical swine fever virus (CSFV) - is a fatal disease of pigs that is responsible for extensive losses to the swine industry worldwide. We had demonstrated previously that a prime-boost vaccination strategy using an alphavirus (Semliki Forest virus, SFV) replicon-vectored DNA vaccine (pSFV1CS-E2) and a recombinant adenovirus (rAdV-E2) expressing the E2 glycoprotein of CSFV induced enhanced immune responses in a mouse model. In this study, we evaluated further the efficacy of the heterologous prime-boost immunization approach in pigs, the natural host of CSFV. The results showed that the pigs (n=5) receiving pSFV1CS-E2/rAdV-E2 heterologous prime-boost immunization developed significantly higher titers of CSFV-specific neutralizing antibodies and comparable CD4(+) and CD8(+) T-cell proliferation, compared to the pigs receiving double immunizations with rAdV-E2 alone. When challenged with virulent CSFV Shimen strain, the pigs of the heterologous prime-boost group did not show clinical symptoms or viremia, which were observed in one of the 5 pigs immunized with rAdV-E2 alone and all the 5 control pigs immunized with an empty adenovirus. The results demonstrate that the heterologous DNA prime and recombinant adenovirus boost strategy can induce solid protective immunity.
authors.affiliation: Division of Swine Infectious Diseases, National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, 427 Maduan Street, Harbin 150001, Heilongjiang, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Hong-Yu
authors.initials: HY
authors.lastname: Li
authors.forename: Miao
authors.initials: M
authors.lastname: Li
authors.forename: Hua-Ji
authors.initials: HJ
authors.lastname: Qiu
mesh_terms: D000256:Adenoviridae / Q000235:genetics*; D000524:Alphavirus / Q000235:genetics*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D006691:Classical Swine Fever / Q000276:immunology*; D006692:Classical Swine Fever Virus / Q000276:immunology; D005822:Genetic Vectors; D007114:Immunization; D007117:Immunization, Secondary; D008213:Lymphocyte Activation; D011995:Recombination, Genetic; D012093:Replicon; D013552:Swine; D019444:Vaccines, DNA / Q000276:immunology*; D019562:Viral Load; D014765:Viral Vaccines / Q000276:immunology*; D014766:Viremia / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D019444:Vaccines, DNA; D014765:Viral Vaccines