title: The N-N non-covalent domain of the nucleocapsid protein of type 2 porcine reproductive and respiratory syndrome virus enhances induction of IL-10 expression.
abstract: Porcine reproductive and respiratory syndrome virus (PRRSV) usually establishes a prolonged infection and causes an immunosuppressive state. It has been proposed that IL-10 plays an important role in PRRSV-induced immunosuppression. However, this mechanism has not been completely elucidated. In this study, we found that transfection of 3D4/2 macrophages with the N protein gene of type 2 PRRSV significantly upregulated IL-10 expression at the transcriptional level. Moreover, alanine substitution mutation analysis revealed that the N protein residues 33-37, 65-68 and 112-123 were related to the upregulation of IL-10 promoter activity. Recombinant PRRSV with mutations at residues 33-37 in the N protein (rQ33-5A and rS36A) recovered from corresponding infectious cDNA clones and induced significantly lower levels of IL-10 production in infected monocyte-derived dendritic cells, as compared with their revertants rQ33-5A(R) and rS36A(R), and the wild-type recombinant PRRSV strain rNT/wt. These data indicate that the type 2 PRRSV N protein plays an important role in IL-10 induction and the N-N non-covalent domain is associated with this activity.
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR 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, PR 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, PR 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, PR 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, PR China.
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, PR China.|Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
mesh_terms: D000818:Animals; D002460:Cell Line; D054884:Host-Pathogen Interactions; D057131:Immune Evasion; D016753:Interleukin-10 / Q000096:biosynthesis*; D008264:Macrophages / Q000276:immunology / Q000821:virology; D019590:Nucleocapsid Proteins / Q000276:immunology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000276:immunology* / Q000502:physiology*; D013552:Swine
chemical_list: D019590:Nucleocapsid Proteins; D016753:Interleukin-10