Mumps Virus Induces Protein-Kinase-R-Dependent Stress Granules, Partly Suppressing Type III Interferon Production

Shin Hashimoto; Soh Yamamoto; Noriko Ogasawara; Toyotaka Sato; Keisuke Yamamoto; Hiroshi Katoh; Toru Kubota; Tsukasa Shiraishi; Takashi Kojima; Tetsuo Himi; Hiroyuki Tsutsumi; Shin-Ichi Yokota

doi:10.1371/journal.pone.0161793

Mumps Virus Induces Protein-Kinase-R-Dependent Stress Granules, Partly Suppressing Type III Interferon Production

PLoS One. 2016 Aug 25;11(8):e0161793. doi: 10.1371/journal.pone.0161793. eCollection 2016.

Authors

Affiliations

¹ Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, Japan.
² Department of Microbiology, Sapporo Medical University School of Medicine, Sapporo, Japan.
³ Department of Otorhinolaryngology, Sapporo Medical University School of Medicine, Sapporo, Japan.
⁴ Department of Virology III, National Institute of Infectious Diseases, Tokyo, Japan.
⁵ Department of Cell Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.

Abstract

Stress granules (SGs) are cytoplasmic granular aggregations that are induced by cellular stress, including viral infection. SGs have opposing antiviral and proviral roles, which depend on virus species. The exact function of SGs during viral infection is not fully understood. Here, we showed that mumps virus (MuV) induced SGs depending on activation of protein kinase R (PKR). MuV infection strongly induced interferon (IFN)-λ1, 2 and 3, and IFN-β through activation of IFN regulatory factor 3 (IRF3) via retinoic acid inducible gene-I (RIG-I) and the mitochondrial antiviral signaling (MAVS) pathway. MuV-induced IFNs were strongly upregulated in PKR-knockdown cells. MuV-induced SG formation was suppressed by knockdown of PKR and SG marker proteins, Ras-GTPase-activating protein SH3-domain-binding protein 1 and T-cell-restricted intracellular antigen-1, and significantly increased the levels of MuV-induced IFN-λ1. However, viral titer was not altered by suppression of SG formation. PKR was required for induction of SGs by MuV infection and regulated type III IFN (IFN-λ1) mRNA stability. MuV-induced SGs partly suppressed type III IFN production by MuV; however, the limited suppression was not sufficient to inhibit MuV replication in cell culture. Our results provide insight into the relationship between SGs and IFN production induced by MuV infection.

MeSH terms

Animals
Blotting, Western
Carrier Proteins / genetics
Cell Line
Chlorocebus aethiops
Cytoplasmic Granules / metabolism
Cytoplasmic Granules / virology*
DEAD Box Protein 58 / metabolism
DNA Helicases
Gene Expression
Host-Pathogen Interactions
Humans
Interferon Regulatory Factor-3 / metabolism
Interferons / biosynthesis*
Interferons / genetics
Microscopy, Confocal
Mitochondria / metabolism
Mumps virus / physiology*
Poly(A)-Binding Proteins / genetics
Poly-ADP-Ribose Binding Proteins
RNA Helicases
RNA Interference
RNA Recognition Motif Proteins
Receptors, Immunologic
Reverse Transcriptase Polymerase Chain Reaction
Signal Transduction
Stress, Physiological / physiology
T-Cell Intracellular Antigen-1
Vero Cells
eIF-2 Kinase / genetics
eIF-2 Kinase / metabolism*

Substances

Carrier Proteins
IRF3 protein, human
Interferon Regulatory Factor-3
Poly(A)-Binding Proteins
Poly-ADP-Ribose Binding Proteins
RNA Recognition Motif Proteins
Receptors, Immunologic
T-Cell Intracellular Antigen-1
TIA1 protein, human
Interferons
eIF-2 Kinase
RIGI protein, human
DNA Helicases
G3BP1 protein, human
DEAD Box Protein 58
RNA Helicases

Grants and funding

N. O. was supported by a Grant-in-Aid for Young Scientists (B) (25861574) and GSK Japan Research Grant 2015. H. T. was supported by a Grant-in-Aid for Scientific Research (B) (26293370) and Challenging Exploratory Research (26670746). T. Kojima was supported by a Grant-in-Aid for Scientific Research (C) (15k08350). K. Y. was supported by a Grant-in- Aid for Young Scientists (B) (16K20266). T. Sato was supported by a Grant-in-Aid for Young Scientists (start-up) (15H06521). None of the funders had any role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.