Pro‐inflammatory caspase‐1 activation during the immune response in cells from rainbow trout Oncorhynchus mykiss (Walbaum 1792) challenged with pathogen‐associated molecular patterns. Issue 11 (5th December 2014)

• Record Type: Journal Article
• Authors: Rojas, V; Camus‐Guerra, H; Guzmán, F; Mercado, L
• Is Part Of: Journal of fish diseases. Volume 38:Issue 11(2015:Nov.)
• Page Start: 993
• Page End: 1003
• Publication Date: 2014-12-05
• Subjects: Fishes -- Diseases -- Periodicals; 639.3
• DOI: 10.1111/jfd.12315
• Languages: English
• ISSNs: 0140-7775

Abstract

<abstract abstract-type="main" id="jfd12315-abs-0001"> <title>Abstract</title> <p>In response to pathogens, the higher vertebrate innate immune system activates pro‐inflammatory caspase‐1 which is responsible for the processing and secretion of several important cytokines involved in the host's defence against infection. To date, caspase‐1 has been described in few teleost fish, and its activity has been demonstrated through substrate cleavage and inhibition by pharmacological agents. In this study, the detection of the active form of caspase‐1 during the immune response in salmonid fish is described, where two antibodies were produced. These antibodies differentially recognize the structural epitopes of the inactive pro‐caspase‐1 and the processed active form of the caspase. Firstly, caspase‐1 activation was demonstrated <italic>in vitro</italic> by ELISA, Western blotting and immunocytochemistry in rainbow trout macrophages exposed to different pathogen‐associated molecular patterns plus the pathogen <italic>Aeromonas hydrophila</italic>. This activity was clearly abrogated by a caspase inhibitor and seems to be unrelated to IL‐1β secretion. Caspase‐1 activation was then validated <italic>in vivo</italic> in gill cells from fish challenged with <italic>Aeromonas salmonicida</italic>. These results represent the first demonstration of caspase‐1 activation in salmonids, and the first evidence of the putative regulatory role which this protease plays in inflammatory response in this fish group, as described for some other teleosts and mammals.</p> </abstract>