How Many Mammalian Reovirus Proteins are involved in the Control of the Interferon Response?

Abstract

As with most viruses, mammalian reovirus can be recognized and attacked by the host-cell interferon response network. Similarly, many viruses have developed resistance mechanisms to counteract the host-cell response at different points of this response. Reflecting the complexity of the interferon signaling pathways as well as the resulting antiviral response, viruses can—and often have—evolved many determinants to interfere with this innate immune response and allow viral replication. In the last few years, it has been evidenced that mammalian reovirus encodes many different determinants that are involved in regulating the induction of the interferon response or in interfering with the action of interferon-stimulated gene products. In this brief review, we present our current understanding of the different reovirus proteins known to be involved, introduce their postulated modes of action, and raise current questions that may lead to further investigations.

Piscine Orthoreovirus-1 Isolates Differ in Their Ability to Induce Heart and Skeletal Muscle Inflammation in Atlantic Salmon (Salmo salar)

“…It is encoded by an internal ORF on the bicistronic S1 segment and thus the coding sequences of p13 and σ3 proteins are intrinsically linked. Several of the structural proteins of reoviruses counteract the innate antiviral activity during replication, including the outer structural protein σ3 and λ2 [ 34 ]. However, the analysis of the innate response did not indicate any substantial differences between low-and high-virulent isolates.…”

Dissemination of Piscine orthoreovirus-1 (PRV-1) in Atlantic Salmon (Salmo salar) during the Early and Regenerating Phases of Infection

“…Antiviral responses have reported that the PRV-1 infection of cultured Atlantic salmon red blood cells induces Mx and Protein kinase R (PKR) [29], the latter being a mediator of translational inhibition [30]. In mammalian orthoreovirus (MRV) infected cells, translational shutoff has been demonstrated through PKR and phosphorylation of the eukaryotic translation initiation factor (eIF)-2α, as part of the interferon-regulated antiviral response [31,32]. Further research would provide more insights into the molecular control mechanisms of PRV replication in target cells, and for the persistence of PRV-1 RNA in salmon erythrocytes, a well-suited cell type for long-term viral persistence.…”

Closely related reovirus lab strains induce opposite expression of RIG-I/IFN-dependent versus -independent host genes, via mechanisms of slow replication versus polymorphisms in dsRNA binding σ3 respectively

“…In addition to inherent advantages in virus replication, it was possible that T3D strains differentially induced host responses and affected virus replication kinetics and oncolytic efficiencies. Indeed, previous studies found differences in interferon responses to distinct reovirus serotypes and lab strains [21][22][23][24][25][26][27]. However, these studies did not investigate the T3D PL strain which is currently in PhaseI/II cancer clinical trials nor compare strains with known differences in in vivo oncolytic activities.…”