The effect of intraperitoneally administered recombinant IL-1β on immune parameters and resistance to Aeromonas salmonicida in the rainbow trout (Oncorhynchus mykiss)

The present work provides the first information concerning the immunostimulatory activity of trout recombinant interleukin-1 beta (rIL-1beta) in vivo. The predicted rainbow trout mature IL-1beta peptide was produced as a recombinant protein in Escherichia coli. Optimal migration of peritoneal leucocytes and rIL-1beta induced phagocytosis occurred following intraperitoneal injection of 1 mug of the recombinant protein. Moreover, systemic IL-1beta, COX-2 and lysozyme 11 gene expression was enhanced following greater than or equal to 1 mug rIL-1beta administration. Finally, resistance to Aeromonas salmonicida, the causative agent of furunculosis, was augmented at early times (2 days) post-injection of 1 mug rIL-1beta. (C) 2003 Elsevier Science Ltd. All rights reserved.