title: Neuroendocrine-immune interactions in fish: a role for interleukin-1.
abstract: Bi-directional communication between the hypothalamus-pituitary-adrenal (HPA)-axis and the sympathetic nervous system with the immune system is crucial to ensure homeostasis. Shared use of ligands and especially receptors forms a key component of this bi-directional interaction. Glucocorticoids (GC), the major end products of the HPA-axis differentially modulate immune function. Cytokines, especially interleukin-1 (IL-1), tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), ensure immune signalling to the neuroendocrine system. In addition, hormones from leukocyte origin such as corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH) and beta-endorphin, as well as centrally synthesised and secreted cytokines, contribute to the communication network. In teleost fish cortisol is the major product of the hypothalamus-pituitary-interrenal (HPI)-axis which is the teleost equivalent of the HPA-axis. Moderate and substantial increases in cortisol during stressful circumstances negatively affect B-lymphocytes, whereas rescue of neutrophilic granulocytes may support innate immunity. Recent elucidation of lower vertebrate cytokine sequences has facilitated research into neuroendocrine-immune interactions in teleosts and the first evidence for a significant function of interleukin-1 in the bi-directional communication is discussed.
authors.affiliation: Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, P.O. Box 338, 6700 AH Wageningen, The Netherlands.
authors.forename: Marc Y
authors.initials: MY
authors.lastname: Engelsma
authors.forename: Mark O
authors.initials: MO
authors.lastname: Huising
authors.forename: Willem B
authors.initials: WB
authors.lastname: van Muiswinkel
authors.forename: Gert
authors.initials: G
authors.lastname: Flik
authors.forename: Jimmy
authors.initials: J
authors.lastname: Kwang
authors.forename: Huub F J
authors.initials: HF
authors.lastname: Savelkoul
authors.forename: B M Lidy
authors.initials: BM
authors.lastname: Verburg-van Kemenade
mesh_terms: D000818:Animals; D005399:Fishes / Q000276:immunology* / Q000502:physiology; D007107:Immune System / Q000502:physiology*; D007375:Interleukin-1 / Q000502:physiology*; D015850:Interleukin-6 / Q000502:physiology; D009490:Neurosecretory Systems / Q000502:physiology*; D010802:Phylogeny; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology
chemical_list: D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha