title: PKR Activation Favors Infectious Pancreatic Necrosis Virus Replication in Infected Cells.
abstract: The double-stranded RNA-activated protein kinase R (PKR) is a Type I interferon (IFN) stimulated gene that has important biological and immunological functions. In viral infections, in general, PKR inhibits or promotes viral replication, but PKR-IPNV interaction has not been previously studied. We investigated the involvement of PKR during infectious pancreatic necrosis virus (IPNV) infection using a custom-made rabbit antiserum and the PKR inhibitor C16. Reactivity of the antiserum to PKR in CHSE-214 cells was confirmed after IFNα treatment giving an increased protein level. IPNV infection alone did not give increased PKR levels by Western blot, while pre-treatment with PKR inhibitor before IPNV infection gave decreased eukaryotic initiation factor 2-alpha (eIF2α) phosphorylation. This suggests that PKR, despite not being upregulated, is involved in eIF2α phosphorylation during IPNV infection. PKR inhibitor pre-treatment resulted in decreased virus titers, extra- and intracellularly, concomitant with reduction of cells with compromised membranes in IPNV-permissive cell lines. These findings suggest that IPNV uses PKR activation to promote virus replication in infected cells.
authors.affiliation: Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., 0033 Oslo, Norway. amr.gamil@nmbu.no.
authors.forename: Amr A A
authors.initials: AA
authors.lastname: Gamil
authors.affiliation: Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., 0033 Oslo, Norway. cheng.xu@nmbu.no.
authors.forename: Cheng
authors.initials: C
authors.lastname: Xu
authors.affiliation: Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., 0033 Oslo, Norway. stephen.mutoloki@nmbu.no.
authors.forename: Stephen
authors.initials: S
authors.lastname: Mutoloki
authors.affiliation: Faculty of Veterinary Medicine and Biosciences, Norwegian University of Life Sciences, P.O. Box 8146 Dep., 0033 Oslo, Norway. oystein.evensen@nmbu.no.
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Evensen
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D005399:Fishes; D054884:Host-Pathogen Interactions; D018061:Infectious pancreatic necrosis virus / Q000502:physiology*; D011817:Rabbits; D019562:Viral Load; D014779:Virus Replication; D019892:eIF-2 Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D019892:eIF-2 Kinase
keywords: IPNV; PKR; PKR inhibitor; cloning; eIF2α phosphorylation; necrosis