title: Expression of interferon-alpha and Mx1 protein in pigs acutely infected with porcine reproductive and respiratory syndrome virus (PRRSV).
abstract: The expression of mRNA encoding interferon-alpha (IFN-alpha) and Mx1 protein was studied, by reverse transcription-polymerase chain reaction and by in-situ hybridization with a non-radioactive digoxigenin-labelled cDNA probe, in formalin-fixed, paraffin wax-embedded lung tissue from pigs experimentally infected with a Korean isolate (North American genotype) of porcine reproductive and respiratory syndrome virus (PRRSV). The animals were examined over a period of 10 days after intranasal inoculation. IFN-alpha and Mx1 protein was detected in the lung at 1 day post inoculation (dpi), the number of positive cells increasing at 7dpi, and rapidly decreasing thereafter. Hybridization signals for IFN-alpha and Mx1 protein were usually associated with inflammation, and in particular with macrophages. Expression of IFN-alpha and Mx1 protein was negative in non-lesional lung of PRRSV-infected pigs and in normal lung from control pigs. There was a good statistical correlation between the number of cells positive for mRNA encoding IFN-alpha and Mx1 protein in the infected lungs (r = 0.95, P< 0.05). The results suggest that the expression of IFN-alpha and Mx1 protein plays a role in the early host defence against PRRSV infection.
authors.affiliation: Department of Veterinary Pathology, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University, San 56-1, Kwanak-Gu, Seoul 151-742, South Korea.
authors.forename: H-K
authors.initials: HK
authors.lastname: Chung
authors.forename: J-H
authors.initials: JH
authors.lastname: Lee
authors.forename: S-H
authors.initials: SH
authors.lastname: Kim
authors.forename: C
authors.initials: C
authors.lastname: Chae
mesh_terms: D000818:Animals; D019204:GTP-Binding Proteins / Q000096:biosynthesis*; D017403:In Situ Hybridization; D016898:Interferon-alpha / Q000096:biosynthesis*; D008168:Lung / Q000378:metabolism* / Q000473:pathology; D008264:Macrophages / Q000378:metabolism; D064547:Myxovirus Resistance Proteins; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology / Q000378:metabolism*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013552:Swine; D013553:Swine Diseases / Q000276:immunology / Q000378:metabolism*
chemical_list: D016898:Interferon-alpha; D064547:Myxovirus Resistance Proteins; D012333:RNA, Messenger; D019204:GTP-Binding Proteins