title: Positive effects of porcine IL-2 and IL-4 on virus-specific immune responses induced by the porcine reproductive and respiratory syndrome virus (PRRSV) ORF5 DNA vaccine in swine.
abstract: The purpose of this study was to investigate the effects of porcine interleukin (IL)-2 and IL-4 genes on enhancing the immunogenicity of a porcine reproductive and respiratory syndrome virus ORF5 DNA vaccine in piglets. Eukaryotic expression plasmids pcDNA-ORF5, pcDNA-IL-2, and pcDNA-IL-4 were constructed and then expressed in Marc-145 cells. The effects of these genes were detected using an indirect immunofluorescent assay and reverse transcription polymerase chain reaction (RT-PCR). Characteristic fluorescence was observed at different times after pcDNA- ORF5 was expressed in the Marc-145 cells, and PCR products corresponding to ORF5, IL-2, and IL-4 genes were detected at 48 h. Based on these data, healthy piglets were injected intramuscularly with different combinations of the purified plasmids: pcDNA-ORF5 alone, pcDNA-ORF5 + pcDNA-IL-2, pcDNA-ORF5 + pcDNA-IL-4, and pcDNA-ORF5 + pcDNA- IL-4 + pcDNA-IL-2. The ensuing humoral immune responses, percentages of CD4(+) and CD8(+) T lymphocytes, proliferation indices, and interferon-g expression were analyzed. Results revealed that the piglets co-immunized with pcDNA-ORF5 + pcDNA-IL-4 + pcDNA-IL-2 plasmids developed significantly higher antibody titers and neutralizing antibody levels, had significantly increased levels of specific T lymphocyte proliferation, elevated percentages of CD4(+) and CD8(+) T lymphocytes, and significantly higher IFN-γ production than the other inoculated pigs (p < 0.05).
authors.affiliation: Department of Animal Science, Guizhou University, Guiyang 550025, China.tdyuan@163.com.
authors.forename: Deyuan
authors.initials: D
authors.lastname: Tang
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Chunyan
authors.initials: C
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Ma
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Luo
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zeng
authors.forename: Nining
authors.initials: N
authors.lastname: Hong
authors.forename: Xia
authors.initials: X
authors.lastname: Liu
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Zhenlei
authors.initials: Z
authors.lastname: Gan
authors.forename: Fei
authors.initials: F
authors.lastname: Hao
mesh_terms: D000818:Animals; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics; D000882:Haplorhini; D007111:Immunity, Cellular; D007376:Interleukin-2 / Q000235:genetics / Q000378:metabolism*; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism*; D009500:Neutralization Tests / Q000662:veterinary; D010957:Plasmids; D019318:Porcine Reproductive and Respiratory Syndrome / Q000517:prevention & control*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013552:Swine; D019444:Vaccines, DNA / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000378:metabolism; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C114789:glycoprotein 5, PRRSV; D015847:Interleukin-4
keywords: IL-2; IL-4; ORF5 DNA vaccine; immunogenicity; porcine reproductive and respiratory syndrome virus