title: Plasmids expressing porcine interferon gamma up-regulate pro-inflammatory cytokine and co-stimulatory molecule expression which are suppressed by porcine reproductive and respiratory syndrome virus.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) suppresses the pro-inflammatory immune response following infection of myeloid antigen-presenting cells. A reduced pro-inflammatory immune response modulates PRRSV replication, clinical disease, and persistent infection of the virus. Numerous efforts have been made to enhance the pro-inflammatory immune response to PRRSV, but only a few attempts have so far elicited satisfactory results. The present study aims to evaluate in vitro the potential of plasmids expressing porcine interferon gamma (pcDNA-IFNγ) to enhance the expression of pro-inflammatory immune parameters in PRRSV-inoculated monocytes. Naïve blood monocytes from eight PRRSV-seronegative pigs were inoculated with PRRSV and subsequently transfected with pcDNA-IFNγ or pcDNA (empty plasmid vector) and stimulated with lipopolysaccharide (LPS). The mRNA expression levels of IFNγ, interleukin-1 beta (IL-1β), IL-10, IL-12p40, tumor necrosis factor alpha (TNFα), transforming growth factor beta (TGFβ), CD80, and CD86 were evaluated by real-time PCR. The IFNγ, IL-10, and TNFα protein production was determined by ELISA. Compared with PRRSV-inoculated monocyte control, transfection with pcDNA-IFNγ, but not pcDNA, significantly enhanced IFNγ, TNFα, CD80, and CD86 mRNA expression, and IFNγ and TNFα protein production. A slight increase in IL-1β and IL-12p40 mRNA expression was also observed. Neither pcDNA-IFNγ nor pcDNA transfection affected IL-10 and TGFβ expression. Our results thus suggest that pcDNA-IFNγ may be an effective immunostimulator for potentiating the pro-inflammatory immune response to PRRSV.
authors.affiliation: Program of Biotechnology, Faculty of Science, Maejo University, Chiang Mai, Thailand. wasin@mju.ac.th
authors.forename: Wasin
authors.initials: W
authors.lastname: Charerntantanakul
authors.forename: Surangkanang
authors.initials: S
authors.lastname: Yamkanchoo
authors.forename: Watchara
authors.initials: W
authors.lastname: Kasinrerk
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics*; D007371:Interferon-gamma / Q000235:genetics / Q000502:physiology*; D009000:Monocytes / Q000276:immunology; D010957:Plasmids; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis; D013552:Swine; D014162:Transfection
chemical_list: D016207:Cytokines; D012333:RNA, Messenger; D007371:Interferon-gamma