Molecular cloning and characterization of Toll-like receptor 3 in Japanese flounder, Paralichthys olivaceus

Structural insights of rohu TLR3, its binding site analysis with fish reovirus dsRNA, poly I:C and zebrafish TRIF

“…The horseshoeshaped solenoid structure of rTLR3-ECD resembles the human TLR3-ECD, indicating the similar type of ligand recognition and interaction. In human, poly I:C binding amino acids residues were detected at LRR21, whereas in rohu fish, the peptides at LRR (4-6), (13)(14) and (20)(21)(22) were predicted as the key domains that may interact and bind with poly I:C. Docking of rTLR3-ECD with the dsRNA of glycoprotein gene of AGCRV,VHSV and IHNV identified LRR8-15 and LRR17-24 as the predominant binding sites. The relatively large number of dsRNA interacting LRR domains in rohu TLR3 may suggest the possibility of a wider region of dsRNA recognition in fish TLR3 as compared to higher vertebrates.…”

“…TLR3 has been identified in various fish species viz., zebrafish (Danio rerio) [15], rainbow trout (Oncorhynchus mykiss) [16], common carp (Cyprinus carpio) [17], rare minnow (Gobiocypris rarus) [18], grass carp (Ctenopharyngodon idella) [19], large yellow croaker (Pseudosciaena crocea) [20] and Japanese flounder (Paralichthys olivaceous) [21]. In zebrafish, the modulation of TLR3 gene expression was reported following the infection with viral hemorrhagic septicemia virus (VHSV), a single stranded RNA (ssRNA) virus, and in grass carp, by the grass carp reovirus (GCRV), a double-stranded RNA (dsRNA) virus [22,23].…”

A toll‐like receptor 3 homologue that is up‐regulated by poly I:C and DNA virus in turbot Scophthalmus maximus

“…crocea (Huang et al , ), and most similar to another flatfish P . olivaceus that also has higher tlr3 transcript levels in the head kidney and heart (Hwang et al , ). On the contrary, the liver was reported to express tlr3 mRNA abundantly in some teleosts (Baoprasertkul et al , ; Huang et al , ), whereas it expressed them much less in S .…”

“…As far as is known, this study is the first report for induction of tlr3 by DNA virus in teleosts although one study reported its up‐regulation with CpG ODN, a synthetic mimic of bacterial and viral DNA, in P . olivaceus (Hwang et al , ).…”

“…rubripes and P . olivaceus , demonstrating that poly I:C stimulation causes Tlr3 to activate IFN and nuclear factor kappa B (NF‐κB) pathway (Phelan et al , ; Matsuo et al , ; Hwang et al , ), suggesting a conserved function of Tlr3 between teleosts and mammals. The information about Tlr3 in turbot Scophthalmus maximus (L. 1758) (Smtlr3), however, is scarce.…”