Toll-like receptors and interferon associated immune factors in viral haemorrhagic septicaemia virus-infected olive flounder (Paralichthys olivaceus)

Effects of NV gene knock-out recombinant viral hemorrhagic septicemia virus (VHSV) on Mx gene expression in Epithelioma papulosum cyprini (EPC) cells and olive flounder (Paralichthys olivaceus)

“…Induction of Mx gene expression by VHSV infection has been demonstrated in vitro and in vivo experiments in rainbow trout [23,24] and in olive flounder [25,26]. Furthermore, antiviral activity of Mx proteins in fish has also been demonstrated from Atlantic salmon Mx1 protein that suppressed infectious pancreatic necrosis virus (IHNV) replication [27], and from olive flounder Mx protein that inhibit replication of two novirhabdoviruses, hirame rhabdovirus (HIRRV) and VHSV [28].…”

Temperature-dependent viral replication and antiviral apoptotic response in viral haemorrhagic septicaemia virus (VHSV)-infected olive flounder (Paralichthys olivaceus)

“…Primers for partial sequencing of caspase 3 (sense primer-5 0 -gtcccacagcttcagatacagc-3 0 , antisense primer 5 0 -gacgtggagacgacatcag-3 0 ; product size: 712 bp) were designed from our cDNA library following earlier described methods [18]. The deduced amino acid sequence showed close homology with the caspase 3 from the fire clownfish (Amphiprion melanopus) (92%), mandarin fish (Siniperca chuatsi) (91%), Atlantic salmon (Salmo salar) (73%), chicken (Gallus gallus) (66%) and human (Homo sapiens) (65%), confirming that the obtained sequence is caspase 3 of the olive flounder.…”

“…Primers for real-time PCR were designed using Primer3-Plus. The primer efficiency was determined as previously described [18]. The details of the primers used for real-time PCR expression study are given in Table 1.…”

“…However, some viruses have developed mechanisms to block or delay early apoptosis so that they can achieve maximum replication [14,16]. Though the recombinant Mx protein was very efficient in controlling the VHSV in in vitro condition [17], VHSV-infected olive flounder containing high viral copies at 15 C expressed high level of Mx transcript but toll-like receptor 7 (TLR-7) and TLR-2 were under-expressed [18]. The non-virion (NV) protein of VHSV is reported to inhibit apoptosis at an early infectious stage to allow effective viral recruitment [19].…”

“…Based on our previous results [18] and the importance of an apoptotic immune defence mechanism, we designed this study to investigate the expression kinetics of apoptosis-associated genes in VHSV-infected olive flounder maintained at two different temperatures. We developed VHSV infection in olive flounder at 15 C and 20 C to study the apoptotic immune response and the viral replication at early infectious as well as later recovery period.…”