title: Prolactin-releasing peptide is a potent mediator of the innate immune response in leukocytes from Salmo salar.
abstract: Prolactin (PRL)-releasing peptide (PrRP) is a strong candidate stimulator of pituitary PRL transcription and secretion in teleosts. However, the role in control of extrapituitary PRL expression or its effects on innate immunity are unclear even in mammals. To study the possible presence of PrRP in peripheral organs, PrRP expression patterns and their effect on innate immunity were characterised in SHK-1 cells and head kidney (HK) leukocytes purified from the salmonid, Salmo salar. We detected immunoreactive cells in leukocytes from blood and HK of S. salar and found that PrRP mRNA was abundantly expressed in these cells. We have recently reported that physiological concentrations of native PRL, downstream of neuropeptide PrRP were able to induce expression of pro-inflammatory cytokines and the production of reactive oxygen species (ROS) in HK leukocytes and macrophages from S. salar and Sparus aurata. It is of interest to note that in this work we have revealed that synthetic PrRP was able to induce expression of pro-inflammatory cytokines (interleukins) IL-1β, IL-6, IL-8, IL-12 and PRL. We also show here that PrRP increased both (ROS) production and phagocytosis. Taken together, our results demonstrate for the first time that PrRP may be a local modulator of innate immune responses in leukocytes from S. salar.
authors.affiliation: Laboratory of Biotechnology and Aquatic Pathology, Faculty of Veterinary Science, Universidad Austral, Campus Isla Teja, Valdivia, Chile. alexromero@uach.cl
authors.forename: Alex
authors.initials: A
authors.lastname: Romero
authors.forename: René
authors.initials: R
authors.lastname: Manríquez
authors.forename: Claudio
authors.initials: C
authors.lastname: Alvarez
authors.forename: Cristina
authors.initials: C
authors.lastname: Gajardo
authors.forename: Jorge
authors.initials: J
authors.lastname: Vásquez
authors.forename: Gudrun
authors.initials: G
authors.lastname: Kausel
authors.forename: Mónica
authors.initials: M
authors.lastname: Monrás
authors.forename: Víctor H
authors.initials: VH
authors.lastname: Olavarría
authors.forename: Alejandro
authors.initials: A
authors.lastname: Yáñez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Enríquez
authors.forename: Jaime
authors.initials: J
authors.lastname: Figueroa
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D015870:Gene Expression; D007113:Immunity, Innate; D007378:Interleukins / Q000235:genetics; D007962:Leukocytes / Q000276:immunology / Q000378:metabolism; D010587:Phagocytosis; D011388:Prolactin / Q000235:genetics; D056690:Prolactin-Releasing Hormone / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016897:Respiratory Burst; D020317:Salmo salar / Q000097:blood / Q000235:genetics / Q000276:immunology*
chemical_list: D029941:Fish Proteins; D007378:Interleukins; D056690:Prolactin-Releasing Hormone; D012333:RNA, Messenger; D011388:Prolactin