Effects of NV gene knock-out recombinant viral hemorrhagic septicemia virus (VHSV) on Mx gene expression in Epithelioma papulosum cyprini (EPC) cells and olive flounder (Paralichthys olivaceus)

NV Proteins of Fish Novirhabdovirus Recruit Cellular PPM1Bb Protein Phosphatase and Antagonize RIG-I-Mediated IFN Induction

“…Indeed, as shown in Fig. S2, NV expression is required for the efficient inhibition of virus-induced IFN, as previously observed1523. By analyzing the LC-MS/MS data, we found that three proteins, DDX3 (a DEAD-box RNA helicase37), EFTUD2 (a spliceosomal GTPase38) and PPM1Bb (a serine/threonine protein phosphatase type 2 C (PP2C)34) were previously described in mammals as regulators of type I IFN production (Fig.…”

“…Indeed, a recombinant IHNV, rIHNV-NVvhsv, in which the IHNV NV gene was replaced by that of VHSV, was shown to replicate efficiently in fish cells and to induce similar cumulative percentage of mortality in vivo in rainbow trout compared to the wild-type (WT) IHNV22. Comparative studies between WT and NV-deletion mutant IHNV or VHSV suggest that NV proteins may downregulate the induction of interferon (IFN) and interferon-stimulated genes (ISG) during in vitro infection of rainbow trout- or cyprinid-derived cell lines1523 and in vivo infection of olive flounder23. Moreover, the inhibition of virus-induced IFN response by NV depends on its localization in the infected-cell nucleus15.…”

Isolation and identification of a viral haemorrhagic septicaemia virus (VHSV) isolate from wild largemouth bass Micropterus salmoides in China

“…The Nv gene of VHSV was approximately 500 bp encoding 14 KDa Nv protein (Schutze, Enzmann, Mundt, & Mettenleiter, ). Regarding the function of Nv protein, several studies have demonstrated that it is necessary for an efficient virus replication by inhibiting the interferon system (Biacchesi et al, ; Kim & Kim, ). Various amino acid changes have been identified in all the proteins of various VHSV isolates exhibiting contrasted virulence phenotypes from highly virulent to attenuated, and any chance or substitution in VHSV protein sequences may affect the pathogenicity of VHSV strains (Boudinot et al, ; Campbell, Collet, Einer‐Jensen, Secombes, & Snow, ; Matlin, Reggio, Helenius, & Simons, ; Tafalla, Chico, Perez, Coll, & Estepa, ).…”

Gilthead seabream (Sparus aurata) Mx gene promoters respond differentially to IPNV and VHSV infections in RTG-2 cells

“…However, it has been recently reported that the non-structural NV protein of VHSV interferes with the IFN signalling pathway, resulting in a poor in vitro and in vivo induction of the Japanese flounder (Paralichthys olivaceus) Mx promoter (Kim and Kim, 2012). In addition, the sole Mx promoter was not stimulated in CHSE-214 cells infected with VHSV (Alvarez-Torres et al, 2014).…”