ABSTRACT
The present work provides the first information concerning the immunostimulatory activity of trout interleukin (IL)-1beta-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-1beta-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 micromol of P3. Furthermore, resistance to viral haemorrhagic septicaemia virus (VHSV) was soon augmented (2 d) post-injection of P3.
Subject(s)
Fish Diseases/immunology , Hemorrhagic Septicemia, Viral/immunology , Interleukin-1/pharmacology , Novirhabdovirus , Oncorhynchus mykiss/virology , Rhabdoviridae Infections/veterinary , Amino Acid Sequence , Animals , Infusions, Parenteral/veterinary , Interleukin-1/immunology , Leukocytes/drug effects , Oncorhynchus mykiss/immunology , Peptides/immunology , Peptides/pharmacology , Phagocytosis/drug effects , Respiratory Burst/drug effectsABSTRACT
The present work provides the first information concerning the immunostimulatory activity of trout recombinant interleukin-1 beta (rIL-1beta) in vivo. The predicted rainbow trout mature IL-1beta peptide was produced as a recombinant protein in Escherichia coli. Optimal migration of peritoneal leucocytes and rIL-1beta induced phagocytosis occurred following intraperitoneal injection of 1 microg of the recombinant protein. Moreover, systemic IL-1beta, COX-2 and lysozyme II gene expression was enhanced following >or=1 microg rIL-1beta administration. Finally, resistance to Aeromonas salmonicida, the causative agent of furunculosis, was augmented at early times (2 days) post-injection of 1 microg rIL-1beta.
Subject(s)
Adjuvants, Immunologic/pharmacology , Aeromonas/immunology , Gram-Negative Bacterial Infections/immunology , Immune System/drug effects , Interleukin-1/pharmacology , Oncorhynchus mykiss/immunology , Animals , Cyclooxygenase 2 , Dose-Response Relationship, Drug , Interleukin-1/biosynthesis , Interleukin-1/genetics , Isoenzymes/biosynthesis , Isoenzymes/genetics , Leukocyte Count , Leukocytes/drug effects , Muramidase/biosynthesis , Muramidase/genetics , Oncorhynchus mykiss/microbiology , Phagocytosis/drug effects , Prostaglandin-Endoperoxide Synthases/biosynthesis , Prostaglandin-Endoperoxide Synthases/geneticsABSTRACT
The present work provides information concerning the immunostimulatory activity of Ergosan, an algal based product, injected intraperitoneally in the rainbow trout (Oncorhynchus mykiss). Ergosan is composed of 0.002% unspecified plant extract, 1% alginic acid from Laminaria digitata, and 98.998% algal based carrier. Migration of leucocytes into the peritoneal cavity was stimulated at doses > or =1 mg ml(-1). A single dose of 1mg significantly augmented the proportion of neutrophils, degree of phagocytosis, respiratory burst activity and expression of interleukin-1beta (IL-1beta), interleukin-8 (IL-8) and one of the two known isoforms of trout tumour necrosis factor-alpha (TNF2) in peritoneal leucocytes at 1 day post-injection. Humoral immune parameters were less responsive to intraperitoneal Ergosan administration, with complement stimulation only evident in the 1mg treated group at 2 days post-injection. Antiprotease and lysozyme activity were unaffected by Ergosan over a 7-day time period at the doses examined.
