title: Rainbow trout CK9, a CCL25-like ancient chemokine that attracts and regulates B cells and macrophages, the main antigen presenting cells in fish.
abstract: CK9 is a rainbow trout (Oncorhynchus mykiss) CC chemokine phylogenetically related to mammalian CCL25. Although CK9 is known to be transcriptionally regulated in response to inflammation particularly in mucosal tissues, its functionality has never been revealed. In the current work, we have demonstrated that CK9 is chemoattractant for antigen presenting cells (APCs) expressing major histocompatibility complex class II (MHC II) on the cell surface. Among these APCs, CK9 has a strong chemotactic capacity for both B cells (IgM+ and IgT+) and macrophages. Along with its chemotactic capacities, CK9 modulated the MHC II turnover of B lymphocytes and up-regulated the phagocytic capacity of both IgM+ cells and macrophages. Although CK9 had no lymphoproliferative effects, it increased the survival of IgT+ lymphocytes. Furthermore, we have established that the chemoattractant capacity of CK9 is strongly increased after pre-incubation of leukocytes with a T-independent antigen, whereas B cell receptor (BCR) cross-linking strongly abrogated their capacity to migrate to CK9, indicating that CK9 preferentially attracts B cells at the steady state or under BCR-independent stimulation. These results point to CK9 being a key regulator of B lymphocyte trafficking in rainbow trout, able to modulate innate functions of teleost B lymphocytes and macrophages.
authors.affiliation: Animal Health Research Center (CISA-INIA), Valdeolmos (Madrid), Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Aquilino
authors.affiliation: Animal Health Research Center (CISA-INIA), Valdeolmos (Madrid), Spain.
authors.forename: Aitor G
authors.initials: AG
authors.lastname: Granja
authors.affiliation: Animal Health Research Center (CISA-INIA), Valdeolmos (Madrid), Spain.
authors.forename: Rosario
authors.initials: R
authors.lastname: Castro
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Tiehui
authors.initials: T
authors.lastname: Wang
authors.affiliation: Animal Health Research Center (CISA-INIA), Valdeolmos (Madrid), Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Abos
authors.affiliation: Animal Physiology Unit, Department of Cell Biology, Physiology and Immunology, School of Biosciences, Universitat Autonoma de Barcelona, Cerdanyola del Valles, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Parra
authors.affiliation: Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Secombes
authors.affiliation: Animal Health Research Center (CISA-INIA), Valdeolmos (Madrid), Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Tafalla
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D001402:B-Lymphocytes / Q000276:immunology*; D018925:Chemokines / Q000378:metabolism*; D019742:Chemokines, CC / Q000276:immunology*; D005260:Female; D008264:Macrophages / Q000276:immunology*; D017686:Oncorhynchus mykiss / Q000276:immunology*
chemical_list: D018925:Chemokines; D019742:Chemokines, CC
keywords: B cells; CCL25; CK9; Immune response; Immunity; Immunology and Microbiology Section; chemokines; rainbow trout oncorhynchus mykiss