Stimulation of non-specific immune functions in seawater-acclimated rainbow trout, Oncorhynchus mykiss, with reference to the role of growth hormone

Effects of short-term growth hormone treatment on liver and muscle transcriptomes in rainbow trout (Oncorhynchus mykiss)

“…Similar to the transgenic fish, we found modulation of the complement factor genes, CCAAT/enhancer-binding protein, and barrier-to-autointegration factor genes via microarray. These are in agreement with previous studies that observed increased immune stimulation following GH administration (4) or seawater acclimation, in which endogenous GH is typically elevated (56,66). However, in the present study, we have also identified immune-related genes that that were not differentially expressed in the GH transgenic fish, indicating a difference in the response between the short-term and long-term effects of GH on the immune system.…”

“…In addition, studies have examined the effects of GH augmentation on aspects of physiology and gene expression in salmonids (3,4,26,44,57,66). In the present study, we characterized the short-term effects of exogenous GH on gene expression in the liver and the muscle of rainbow trout (Oncorhynchus mykiss), using a combination of microarray analysis and real-time PCR verification.…”

Growth hormone (GH) treatment acts on the endocrine and autocrine/paracrine GH/IGF-axis and on TNF-α expression in bony fish pituitary and immune organs

“…Furthermore, GH stimulated respiratory burst in vibriosis-furunculosis-vaccinated rainbow trout [28] and plasma lysozyme activity in rainbow trout and channel catfish [29,30]. The stimulatory effects of GH on fish immune functions may be mediated via IGF-I as indicated by the presence of IGF-I gene and peptide in immune tissues [22,31e35], where in tilapia, it has been localised to interrenal cells of the head kidney [31] and to head kidney and spleen leukocytes [22,35].…”

Expression of interferon type I and II, Mx and γIP genes in the kidney of Atlantic salmon, Salmo salar, is induced during smolting

“…For Atlantic salmon smolts, an intact responsive immune system, particularly innate responses, would seem highly important as when they enter the marine environment they are confronted with a range of new pathogens which they have not encountered before in freshwater, including viruses like infectious pancreatic necrosis virus (IPNV), infectious salmon anaemia virus (ISAV) and pancreas disease virus (PDV). It may be highly relevant that growth hormone and prolactin stimulate many aspects of innate immunity such as phagocytosis, lysozyme and mitogenesis [7,9]. Cytokines are important regulators of immune responses and recently increased expression of cytokine genes involved in regulating inflammation and phagocyte functions, interleukin (IL)-1b, tumour necrosis factor (TNF)-a and COX-2 have been found in the kidney and spleen of Atlantic salmon in the month prior to sea water transfer, suggesting that immunostimulatory effects of cytokines may accompany smolting [18].…”