title: Enhancement of the immunogenicity of an alphavirus replicon-based DNA vaccine against classical swine fever by electroporation and coinjection with a plasmid expressing porcine interleukin 2.
abstract: Alphavirus replicon-based DNA vaccines have emerged as a promising approach to generation of antigen-specific immune responses. However, due to their low immunogenicity, there is a need for other approaches to enhance the vaccine potency. In this study, electroporation (EP) and a plasmid expressing porcine interleukin 2 (IL-2) were used to improve the immunogenicity of an alphavirus replicon-based DNA vaccine pSFV1CS-E2 against classical swine fever (CSF). Pigs were immunized with pSFV1CS-E2 alone or together with IL-2 by EP or by simple intramuscular injection. The results showed that EP combined with IL-2 resulted in marked enhancement of E2-specific antibody responses. Moreover, CSFV-specific lymphocyte proliferation, IFN-γ and IL-4 responses were increased significantly in the pSFV1CS-E2+IL-2/EP group. Pigs immunized with pSFV1CS-E2 plus IL-2 by EP were completely protected from lethal challenge, which is comparable to the sterilizing immunity and full protection offered by the live attenuated vaccine C-strain and in contrast with the incomplete protection conferred by pSFV1CS-E2 without or with IL-2 or EP alone, as demonstrated by the presence of pathological changes or/and viral loads. We conclude that EP in combination with IL-2 can significantly improve the immunogenicity of the plasmid DNA vaccine.
authors.affiliation: Division of Swine Infectious Diseases, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, China.
authors.forename: Da-Yong
authors.initials: DY
authors.lastname: Tian
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Sing Fai
authors.initials: SF
authors.lastname: Wai
authors.forename: Fuk Ki
authors.initials: FK
authors.lastname: Lee
authors.forename: Qi-Lin
authors.initials: QL
authors.lastname: Meng
authors.forename: Kar Man
authors.initials: KM
authors.lastname: Suen
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Han
authors.forename: Su
authors.initials: S
authors.lastname: Li
authors.forename: Yong-Feng
authors.initials: YF
authors.lastname: Li
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Ling
authors.forename: Ya-Jin
authors.initials: YJ
authors.lastname: Liao
authors.forename: Hua-Ji
authors.initials: HJ
authors.lastname: Qiu
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000235:genetics; D000524:Alphavirus / Q000235:genetics*; D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D049109:Cell Proliferation; D006691:Classical Swine Fever / Q000276:immunology / Q000517:prevention & control*; D018274:Electroporation / Q000379:methods*; D005822:Genetic Vectors; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000008:administration & dosage* / Q000235:genetics; D015847:Interleukin-4 / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology; D010957:Plasmids / Q000008:administration & dosage; D013552:Swine; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007376:Interleukin-2; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D015847:Interleukin-4; D007371:Interferon-gamma