title: The teleost acute-phase inflammatory response and caspase activation by a novel alarmin-like ligand.
abstract: This study tested the hypothesis that NCAMP-1 has alarmin-like properties and activates the caspase-1-binding site in cells of the teleost bone marrow (equivalent). In mammals, alarmins have been studied extensively; however, in teleosts, little is known about their identity and functions. Similar to alarmins, NCAMP-1 has a broad spectrum of bacteriolytic activity. NCAMP-1 is constitutively present in CF serum, and levels were increased following infection with Edwardsiella ictaluri Binding to AK cells was determined with rNCAMP-1 and an anti-His-tag antibody. In vitro treatment of AK (bone marrow equivalent) or spleen cells with rNCAMP-1 increased the IL-1β message three- to fivefold at 3 h, 6 h, and 9 h post-treatment. The association of NCAMP-1 with the activities of alarmin ATP and the acute inflammatory response was demonstrated by NCAMP-1-induced P2X7R pore opening and YO-PRO-1 cellular influx. The association of NCAMP-1 binding with inflammasome activation was demonstrated by NCAMP-1 activation of the caspase-1-binding site for tetrapeptide Z-YVAD-FMK. In competition assays, this tetrapeptide competitively inhibited subsequent binding by the pan-caspase substrate tripeptide FAM-VAD-FMK. Lymphocyte-like cells from the spleen were 16%+, and epithelial cells were also positive for NCAMP-1. IHC staining and confocal microscopy confirmed the cytosolic existence of NCAMP-1 in lymphoreticular tissue and IL-1β in AK cells. CF T cell lines G14D and 28S.3 expressed NCAMP-1 in the cytosol and in storage granules. These studies strongly suggested that NCAMP-1 is an alarmin-like ligand with similar but distinct activities to those of ATP and HMGB-1.
authors.affiliation: Departments of Infectious Diseases and.
authors.forename: Liliana
authors.initials: L
authors.lastname: Jaso-Friedmann
authors.affiliation: Departments of Infectious Diseases and.
authors.forename: John H
authors.initials: JH
authors.lastname: Leary
authors.affiliation: Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: Camus
authors.affiliation: Departments of Infectious Diseases and dlevans@uga.edu.
authors.forename: Donald L
authors.initials: DL
authors.lastname: Evans
mesh_terms: D000210:Acute-Phase Reaction / Q000276:immunology*; D000067531:Alarmins / Q000276:immunology*; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000276:immunology*; D020169:Caspases / Q000276:immunology*; D020610:Edwardsiella ictaluri / Q000276:immunology*; D004756:Enterobacteriaceae Infections / Q000276:immunology*; D004789:Enzyme Activation; D029941:Fish Proteins / Q000276:immunology*; D005399:Fishes / Q000276:immunology*
chemical_list: D000067531:Alarmins; D023181:Antimicrobial Cationic Peptides; D029941:Fish Proteins; D020169:Caspases
keywords: competitive inhibition; cytokines; inflammasome; inflammation; innate immunity; pathogens