Modulation of the Tissue Expression Pattern of Zebrafish CRP-Like Molecules Suggests a Relevant Antiviral Role in Fish Skin

Abstract

Recent studies suggest that short pentraxins in fish might serve as biomarkers for not only bacterial infections, as in higher vertebrates including humans, but also for viral ones. These fish orthologs of mammalian short pentraxins are currently attracting interest because of their newly discovered antiviral activity. In the present work, the modulation of the gene expression of all zebrafish short pentraxins (CRP-like proteins, CRP1-7) was extensively analyzed by quantitative polymerase chain reaction. Initially, the tissue distribution of crp1-7 transcripts and how the transcripts varied in response to a bath infection with the spring viremia of carp virus, were determined. The expression of crp1-7 was widely distributed and generally increased after infection (mostly at 5 days post infection), except for crp1 (downregulated). Interestingly, several crp transcription levels significantly increased in skin. Further assays in mutant zebrafish of recombinant activation gene 1 (rag1) showed that all crps (except for crp2, downregulated) were already constitutively highly expressed in skin from rag1 knockouts and only increased moderately after viral infection. Similar results were obtained for most mx isoforms (a reporter gene of the interferon response), suggesting a general overcompensation of the innate immunity in the absence of the adaptive one.

Characterization of the innate immune response to Streptococcus pneumoniae infection in zebrafish

“…As in humans, at least some of the zebrafish Crp isoforms seem to be acute phase proteins since their expression is induced upon bacterial as well as viral infections [138,156,157]. In the case of crp2-1, this was also evident in our data.…”

Transcriptome and Genome Analyses Applied to Aquaculture Research

“…The authors also found that 11 of these TRIMs were significantly induced during grass carp reovirus (GCRV) infection and, by co-expression analyses, they identified three trim genes that could be considered as a part of the type I interferon response [ 3 ]. On the other hand, Bello-Perez et al [ 4 ] analyzed the expression of the seven C-reactive proteins (CRPs) previously identified in zebrafish ( Danio rerio ) under basal conditions and after spring viraemia of carp virus (SVCV) infection in different tissues. Most of these crp genes were altered after the viral challenge in different tissues, including the skin.…”

“…Most of these crp genes were altered after the viral challenge in different tissues, including the skin. This tissue also showed a higher expression of these genes in the recombinant activation gene 1 ( rag1 ) mutant zebrafish compared to their wild-type counterparts, suggesting an overcompensation of the innate immune in the absence of the adaptive one [ 4 ]. Finally, Pereiro et al [ 5 ] analyzed by RNA-Seq the repertoire of long non-coding RNAs (lncRNAs) in the brain and head kidney from European sea bass ( Dicentrarchus labrax ) and identified those lncRNAs significantly modulated after infection with nodavirus.…”