Effect of intraperitoneally administered IL-1b-derived peptides on resistance to viral haemorrhagic septicaemia in rainbow trout Oncorhynchus mykiss

Abstract

The present work provides the first information concerning the immunostimulatory activity of trout interleukin (IL)-1β-derived peptides in vivo. Previous studies have demonstrated the ability of 2 such peptides, referred to as P1 and P3, to up-regulate a range of important immune parameters in vitro. P1 corresponds to fragment 146-157 (YVTPVPIETEAR) of the trout sequence and is analogous to a biologically active mammalian IL-1β-derived peptide, whilst P3 was synthesised to complex with the IL-1 receptor and corresponds to fragment 197-206 (YRRNTGVDIS) of the trout sequence. Optimal migration of peritoneal leucocytes, peptide induced phagocytosis and intracellular respiratory burst activity occurred following intraperitoneal injection of 3.0 µmol of P3. Furthermore, resistance to viral haemorrhagic septicaemia virus (VHSV) was soon augmented (2 d) post-injection of P3.KEY WORDS: Interleukin-1β · Phagocytosis · Respiratory burst · Disease resistance · Immunomodulation · VHS 56: 195-200, 2003 cytes (Peddie et al. 2002a). Although bioactive in its own right, the ability of P1 to enhance leucocyte migration and phagocytosis is enhanced when it is combined with P3 (Peddie et al. , 2002a. Resale or republication not permitted without written consent of the publisherDis Aquat OrgThe aim of this paper is to investigate the ability of IL-1β-derived peptides, particularly P3, to enhance leucocyte migration, phagocytic activity and superoxide anion production in the peritoneal cavity of rainbow trout. Furthermore, the ability of these peptides to enhance resistance to viral haemorrhagic septicaemia virus (VHSV) is ascertained. MATERIALS AND METHODSProduction of peptides. Three peptides, referred to as P1, P2 and P3, were synthesised at the Proteome Facility, University of Aberdeen, Scotland, UK. P1 corresponded to fragment 146-157 (YVTPVPIETEAR) of the trout IL-1β sequence (Zou et al. 1999), and had a molecular weight (MW) of 1.37 kDa. P2 was used as an immunologically irrelevant peptide and consisted of the same 12 amino acids as P1, but arranged in a random sequence (VVEEYIRAPPTT). P3 corresponded to fragment 197-206 (YRRNTGVDIS) of the trout sequence and had a MW of 1.18 kDa. Additional details of each peptide are presented in Peddie et al. (2001).Peptides were dissolved in 10 ml sterile 0.15 M phosphate buffered saline (PBS, Gibco), pH 7.2, and sonicated on ice. Stock solutions (10 mM) were stored in 0.5 ml aliquots at -80°C until required. Final concentrations were obtained by diluting the necessary volume of stock solution in sterile PBS.Fish maintenance. Rainbow trout weighing 100 to 500 g were obtained from Almondbank trout farm (Perthshire, UK), stocked in 250 l tanks at the Zoology Department, University of Aberdeen, maintained at 12 ± 1°C, with a constant flow of aerated and dechlorinated mains water. For the VHSV challenge experiment, trout (average weight 10 g) were maintained at the SEERAD Marine Laboratory, Aberdeen. Fish were fed ad libitum daily with commercial pellets (Ewos). An acclimation pe...

Differential Expression of Immune Genes in Atlantic Salmon (Salmo salar L.) Challenged Intraperitoneally or by Cohabitation with IPNV

“…Surprisingly, at all samplings the pro‐inflammatory cytokine IL‐1β was only weakly upregulated. IL‐1β has earlier been shown to be significantly upregulated during an infection with VHSV and in vivo administration of IL‐1β derived peptides conferred to resistance against VHSV in rainbow trout 2 days post‐administration indicating an importance of IL‐1β in the antiviral response [28, 29]. In this experiment the first sampling date was approximately 2 weeks after ip‐challenge and this was probably the reason why IL‐1β was so weakly induced.…”

Quantitative expression profiling of immune response genes in rainbow trout following infectious haematopoietic necrosis virus (IHNV) infection or DNA vaccination

“…In particular, IL-1b1 was elevated over 500 fold in the IHNV infected fish. Injection of IL-1b1 derived peptides into rainbow trout has been shown previously to confer transient resistance to VHSV challenge [53]. Considerable variation in response was observed among individual fish challenged with the live virus; however, individual fish either responded with up-regulation of all genes (except TGF-b1) or did not respond (only 1 individual out of 5 did not respond) (Fig.…”

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

“…IL 1b and IL 8 were elevated throughout the experimental period, whereas IL 6 was elevated after 1 dpi. IL 1b inhibits VHSV [40]; a higher IL 1b level was observed in fish with more viral copies stressing its anti-VHSV role in olive flounder. A similar observation was reported in IHNV-infected rainbow trout [44].…”