Rainbow trout Oncorhynchus mykiss ladderlectin, but not intelectin, binds viral hemorrhagic septicemia virus IVb

Abstract

The innate immune system of fish is critical for rapid detection and immediate response to infection, as well as to orchestrate the adaptive branch of the immune system. Rainbow trout Oncorhynchus mykiss ladderlectin and intelectin are plasma pattern recognition receptors (PRR) for bacterial and fungal pathogens of rainbow trout, but their role as PRRs for virus is unknown. Viral hemorrhagic septicemia virus (VHSV) IVb is a recently described fish pathogen in the Great Lakes, and rainbow trout can be experimentally infected. Using an indirect enzyme-linked immunosorbent assay, rainbow trout plasma ladderlectin significantly (p < 0.05) bound purified VHSV while int electin did not. In addition, plasma ladderlectin but not intelectin was eluted from a VHSV-conjugated Toyopearl column using EDTA. Protein identification was confirmed with polyclonal antiserum used with slot immunoblot, 1-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis, and Western immunoblot.KEY WORDS: Oncorhychus mykiss · Pattern recognition receptor · Viral hemorrhagic septicemia virus · Innate immunity · Plasma proteins · Binding · Ladderlectin · Intelectin Resale or republication not permitted without written consent of the publisherDis Aquat Org 95: [137][138][139][140][141][142][143] 2011 in rainbow trout by 7 d and lasting up to 21 d (Acosta et al. 2005). A DNA vaccine for VHSV conferred shortterm protection of rainbow trout Oncorhynchus mykiss from infection with heterologous rhabdoviruses and the unenveloped nodavirus of turbot (Sommerset et al. 2003). Resistance was hypothesized to be due to the initial inflammatory response that is likely to produce innate antiviral proteins such as interferon and Mx (Sommerset et al. 2003). Mx proteins are one of the major families of interferon-stimulated proteins resulting from innate immune recognition of viral infection (Ellis 2001). More recently, VHSV has been shown to stimulate multiple components of the innate immune system. In gilthead seabream Sparus aurata, VHSV has been shown to recruit and increase the activity of natural cytotoxic cells (NCC) (Esteban et al. 2008). Rainbow trout TLR9 was upregulated at the site of injection of VHSV glycoprotein G in muscle, suggesting the recruitment of dendritic cells to the site; in the head kidney and spleen there was transcriptional increase of tumor necrosis factor alpha and interleukin-6, which are cytokines known to be upregulated by TLR9 activated by unmethylated CpG DNA (Ortega-Villaizan et al. 2009). In addition, the RIG-I/MAVS pathway of double stranded RNA-stimulated interferon induction has been documented in numerous fish species (Biacchesi et al. 2009), and Mx transcript upregulation has been shown in rainbow trout (Acosta et al. 2005) in response to VHSV infection. In Japanese flounder Paralichthys olivaceus, VHSV infection upregulates the hepatic expression of C3 and complement regulatory proteins (Byon et al. 2006).Lectins are cell-associated or circulating proteins involved in recognition and binding of vir...

Whole genome re-sequencing reveals recent signatures of selection in three strains of farmed Nile tilapia (Oreochromis niloticus)

“…Streptococcosis is an important disease, and the outbreaks affect the advancement of tilapia aquaculture globally. Also, we found the Ladderlectin gene, which has been associated with an innate immune response mechanism, that corresponds to plasma pattern recognition for bacterial, fungal and viruses in rainbow trout 66 .…”

“…Streptococcosis is an important disease, and the outbreaks affect the advancement of tilapia aquaculture globally. Also, we found the Ladderlectin gene, which has been associated with an innate immune response mechanism, that corresponds to plasma pattern recognition for bacterial, fungal and viruses in rainbow trout 66 . www.nature.com/scientificreports/ Through captivity, fish populations present changes in behavior-related traits as well, including aggressiveness, foraging, anti-predator and reproductive behavior, which frequently decrease in complexity 36 .…”

Dietary inclusion of Antarctic krill meal during the finishing feed period improves health and fillet quality of Atlantic salmon (Salmo salarL.)

“…The up-regulation of tight junction proteins (connexin, 1•6-fold) indicates improved cell-cell communication of salmon fed krill-supplemented diets, and Willebrords et al (58) reported involvement of connexin hemichannels in non-alcoholic steatohepatitis. Among genes shown to have a role in immune surveillance of KM was up-regulation of ladderlectin (three genes, 1•5-1•8 fold) with broad pathogen recognition in rainbow trout (59)(60)(61) . In addition to liver, dietary krill meal inclusion appeared to improve gut health as ectopic epithelial cells and focal Ca deposits were not observed in KM.…”

Influence of environmental conditions at spawning sites and migration routes on adaptive variation and population connectivity in Chinook salmon

“…Ladderlectin in rainbow trout ( O . mykiss ) has been shown to be involved in the immune response for bacterial and fungal pathogens (Reid et al, 2011). In addition, the FLK, FST, and SFST test identified regions on Chr10, Chr12, Chr13, Chr14, and Chr17 (Figure Sa,b,d).…”

“…A custom set of scripts were used to merge chromosome and scaffold level genepop files into one (https://github.com/esnie lsen/MSc-bioin forma tics). An R script (Ravinet, 2014) was used to convert the genepop file to a BayeScan input file. BayeScan was run using the SNP matrix option and a prior odds of 100.…”