title: Unmethylated CpG oligodeoxynucleotides activate head kidney leukocytes of Atlantic cod, Gadus morhua.
abstract: Bacterial DNA and synthetic oligodeoxynucleotides (ODNs) that contain unmethylated CpG motifs are strong inducers of immune response in most mammalian organisms. The use of these synthetic CpG motifs in fish, particularly in salmonids and carp, resulted in the modulation of their immune system. However, much less is known in other species of fish such as gadoids including Atlantic cod, Gadus morhua. Using head kidney (HK) leukocytes of cod in an in vitro study, we determined the effects of some established CpG-ODNs on the cellular responses of the fish immunocytes. Incubation of the HK leukocytes with 2 μM concentration of the CpG-ODNs resulted in enhanced respiratory burst. There were differential effects on the activities of acid phosphatase and cellular myeloperoxidase. Only CpG-ODN 1826 triggered a significant increase in the level of both enzymes. On the other hand, the supernatants derived from the HK leukocytes after incubation with different CpG-ODNs did not possess bactericidal activity against Vibrio anguillarum and Aeromonas salmonicida. This study has shown that CpG-ODNs at low concentrations are able to stimulate respiratory burst in cod but have minimal effects on cellular enzymatic activities and antibacterial action.
authors.affiliation: Faculty of Biosciences and Aquaculture, Bodø University College, 8049, Bodø, Norway. cmacaipang@yahoo.com
authors.forename: Christopher Marlowe A
authors.initials: CM
authors.lastname: Caipang
authors.forename: Sanchala
authors.initials: S
authors.lastname: Gallage
authors.forename: Carlo C
authors.initials: CC
authors.lastname: Lazado
authors.forename: Monica F
authors.initials: MF
authors.lastname: Brinchmann
authors.forename: Viswanath
authors.initials: V
authors.lastname: Kiron
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D048409:Aeromonas salmonicida / Q000187:drug effects; D000704:Analysis of Variance; D000818:Animals; D048389:Gadus morhua / Q000235:genetics / Q000276:immunology*; D066298:In Vitro Techniques; D007668:Kidney / Q000166:cytology / Q000276:immunology*; D007962:Leukocytes / Q000187:drug effects*; D009838:Oligodeoxyribonucleotides / Q000235:genetics / Q000276:immunology / Q000494:pharmacology*; D009195:Peroxidase / Q000378:metabolism; D016897:Respiratory Burst / Q000187:drug effects*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014733:Vibrio / Q000187:drug effects
chemical_list: C408982:CPG-oligonucleotide; D009838:Oligodeoxyribonucleotides; D013778:Tetrazolium Salts; D013844:Thiazoles; D009195:Peroxidase; D000135:Acid Phosphatase; C022616:thiazolyl blue