Genomic analysis and pathogenic characteristics of Type 2 porcine reproductive and respiratory syndrome virus nsp2 deletion strains isolated in Korea

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

“…onwards. The aa 33-37, 65-68 and 112-123 (except 117) of the N protein were conserved in different type 2 PRRSV strains (data not shown); however, the extents of IL-10 induction were distinct (Choi et al, 2014;Guo et al, 2013;Zhang et al, 2013). This finding suggested that other regions of the viral genome might also be related to IL-10 induction.…”

Pathogenicity and genetic characteristics associated with cell adaptation of a virulent porcine reproductive and respiratory syndrome virus nsp2 DEL strain CA-2

“…The cells were maintained at 37 C in a humidified 5% CO 2 incubator. The PRRSV CA-2 strain was described previously and was propagated in MARC-145 or PAM-pCD163 cells (Choi et al, 2014). The CA-2 virus was plaque purified twice in MARC-145 cells, and the purified virus was serially passaged on MARC-145 cells as described previously with some modifications (Lee and Yoo, 2005).…”

“…Virus titers were measured by 10-fold serial dilutions of each serum sample on target cells in 96-well microtiter plates through immunofluorescence assay in duplicate as described previously (Choi et al, 2014) and then calculated as TCID 50 per ml using the Spearman-Kärber method (Finney, 1978).…”

“…The type 2 PRRSV lineage 1 includes virulent MN184 and its relative strains with a notable discontinuous 111-1-19 deletion of 131 amino acids within the middle hypervariable region 2 (HV2) of nsp2 (nsp2 111-1-19 DEL) compared to type 2 prototype VR-2332 (Brockmeier et al, 2012;Han et al, 2006). The MN184-related nsp2 DEL variant first emerged in South Korea likely in the early 2010s and has since spread across the country, causing severe PRRS outbreaks (Choi et al, 2014).…”

Effect of Nonstructural Protein 2 Hypervariable Regions in the Replication of Porcine Reproductive and Respiratory Syndrome Virus in Marc-145 Cells

“…ORF1a encodes Nsp1α, Nsp1β, Nsp2-Nsp6, Nsp7α, Nsp7β and Nsp8, and ORF1b encodes Nsp9-Nsp12 [8,[10][11][12] . Nsp2, the largest Nsp ( ∼ 2.9 kb) is notable for its genetic heterogeneity and relevance to virus replication [13][14][15][16] . It is associated with PRRSV cell and tissue tropism, and may participate in multiprotein assembly, forming viral replication complexes [17] .…”