Fish Innate Immune Response to Viral Infection—An Overview of Five Major Antiviral Genes

Abstract

Fish viral diseases represent a constant threat to aquaculture production. Thus, a better understanding of the cellular mechanisms involved in establishing an antiviral state associated with protection against virus replication and pathogenesis is paramount for a sustainable aquaculture industry. This review summarizes the current state of knowledge on five selected host innate immune-related genes in response to the most relevant viral pathogens in fish farming. Viruses have been classified as ssRNA, dsRNA, and dsDNA according to their genomes, in order to shed light on what those viruses may share in common and what response may be virus-specific, both in vitro (cell culture) as well as in vivo. Special emphasis has been put on trying to identify markers of resistance to viral pathogenesis. That is, those genes more often associated with protection against viral disease, a key issue bearing in mind potential applications into the aquaculture industry.

Self-assembling ferritin nanoplatform for the development of infectious hematopoietic necrosis virus vaccine

“…Our results showed that FerritVac NPs upregulated the expression of innate antiviral and relevant gene markers of IHNV and other fish Rhabdovirus infection, including mx, vig1, ifit5 , and isg-15 , in antigen-presenting cells, trout head kidney macrophages ( 33 , 34 ). Type I IFNs interfere with viral infection through the induction of a vast repertoire of ISGs via the Jak/STAT pathway, some of the ISGs exerting a direct antiviral activity such as mx, viperin/vig1, and isg15 ( 50 ), the expression of which can be simulated during IHNV infection ( 34 ).…”

“…Untreated cells and cells treated with 25 µg/mL of Ferritin and iRFP were used as controls. Genes tested included mx, vig1, ifit5 , and isg-15 , which are relevant markers of innate antiviral immunity, IHNV, and other fish rhabdovirus infections ( 33 , 34 ). For all genes tested, FerritVac NPs exposure induced up-regulation significantly different from the controls in a dose-dependent manner ( Figure 5 ).…”

“…Total RNA was then extracted from the cells using the ReliaPrep™ RNA Cell Miniprep System (Promega), and cDNA was synthesized using the GoScript™ Reverse Transcription System Kit (Promega). The qPCR was performed using Fast SYBR™ Green Master Mix (ThermoFisher, DE) ( 32 ),, for gene markers of the innate immune response to viral infection ( mx, vig1, ifit5 , and isg-15 ) ( 33 , 34 ),. The expression of the target genes has been corrected based on a reference gene ( EF-1 α ) and calculated relative to the control via the 2 - ΔΔCt method ( 35 ).…”