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 Liu, Xing and Fan, Baochao and Bai, Juan and Wang, Haiyan and Li, Yufeng and Jiang, Ping,, 96, 1276-1286 (2015), doi = https://doi.org/10.1099/vir.0.000061, publicationName = Microbiology Society, issn = 0022-1317, 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., language=, type=