title: The gene expression profile of porcine alveolar macrophages infected with a highly pathogenic porcine reproductive and respiratory syndrome virus indicates overstimulation of the innate immune system by the virus.
abstract: Since the highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) variant emerged in 2006, it has caused death in more than 20 million pigs in China and other Southeast Asian countries, making it the most destructive swine pathogen currently in existence. To characterize the cellular responses to HP-PRRSV infection, the gene expression profile of porcine alveolar macrophage (PAM) cells, the primary target cells of PRRSV, was analyzed in HP-PRRSV-infected and uninfected PAMs by suppression subtractive hybridization. After confirmation by Southern blot, genes that were differentially expressed in the HP-PRRSV-infected and uninfected PAMs were sequenced and annotated. Genes that were upregulated mainly in HP-PRRSV-infected PAM cells were related to immunity and cell signaling. Among the differentially expressed genes, Mx1 and HSP70 protein expression was confirmed by western blotting, and IL-8 expression was confirmed by ELISA. In PAM cells isolated from HP-PRRSV-infected piglets, the differential expression of 21 genes, including IL-16, TGF-beta type 1 receptor, epidermal growth factor, MHC-I SLA, Toll-like receptor, hepatoma-derived growth factor, FTH1, and MHC-II SLA-DRB1, was confirmed by real-time PCR. To our knowledge, this is the first study to demonstrate differential gene expression between HP-PRRSV-infected and uninfected PAMs in vivo. The results indicate that HP-PRRSV infection excessively stimulates genes involved in the innate immune response, including proinflammatory cytokines and chemokines.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, CAAS, No. 427 Maduan Street, Nangang District, Harbin, 150001, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Xiao
authors.forename: Tong-Qing
authors.initials: TQ
authors.lastname: An
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Tian
authors.forename: Tian-Chao
authors.initials: TC
authors.lastname: Wei
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Jiang
authors.forename: Jin-Mei
authors.initials: JM
authors.lastname: Peng
authors.forename: Yan-Jun
authors.initials: YJ
authors.lastname: Zhou
authors.forename: Xue-Hui
authors.initials: XH
authors.lastname: Cai
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Tong
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002681:China; D004797:Enzyme-Linked Immunosorbent Assay; D020869:Gene Expression Profiling; D007113:Immunity, Innate; D016676:Macrophages, Alveolar / Q000276:immunology* / Q000821:virology*; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology* / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D013552:Swine