title: Effect of amino acids residues 323-433 and 628-747 in Nsp2 of representative porcine reproductive and respiratory syndrome virus strains on inflammatory response in vitro.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen that is responsible for large economic losses in the swine industry worldwide. In PRRSV strains, many genetic variations occur in the central hypervariable region (HV2) of the Nsp2 gene, which encodes non-structural protein 2. For example, PRRSV strains VR2332, Em2007, MN184C, and TJM-F92 contained variations in the Nsp2 sequences and exhibited differing levels of virulence in adult pigs. However, the role of HV2 with respect to PRRSV immunity is unclear. In this study, four recombinant PRRSV strains (rBB/+30aa, rBB/Δ68aa, rBB/Δ111aa, and rBB/Δ120aa) were rescued using a highly pathogenic type 2 PRRSV cDNA clone (pBB). All rescued strains displayed similar growth characteristics to the parental rBB virus in pulmonary alveolar macrophages (PAMs). Expression levels of inflammatory cytokines IL-β, IL-6, and TNF-α were significantly lower, at the mRNA and protein level, for groups infected with rBB/Δ111aa and rBB/Δ120aa than those in the rBB group. Levels of these inflammatory cytokines in the rBB/+30aa and rBB/Δ68aa groups were not significantly different with those in the rBB group. Phosphorylation levels of IκB were decreased to a greater extent in the rBB/Δ111aa and rBB/Δ120aa groups compared with those in the rBB/+30aa, rBB/Δ68aa, and rBB groups. Our results indicate that amino acids 323-433 and 628-747 of Nsp2 failed to exert significant effects on PRRSV replication in PAMs, but modulated the expression of inflammatory cytokines in vitro.
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Bai
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Baochao
authors.initials: B
authors.lastname: Fan
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address: jiangp@njau.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002460:Cell Line; D015850:Interleukin-6 / Q000235:genetics / Q000276:immunology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000235:genetics / Q000276:immunology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000737:chemistry / Q000235:genetics / Q000276:immunology* / Q000502:physiology; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D014779:Virus Replication
chemical_list: D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D017361:Viral Nonstructural Proteins
keywords: Inflammatory cytokines; Nsp2; PRRSV