The production and bioactivity of rainbow trout (Oncorhynchus mykiss) recombinant IL-1 beta

The predicted rainbow trout mature interleukin-1 beta (IL-1 beta) peptide h as been produced as a recombinant protein in E. coli, The bioactivity of th is molecule has been studied using trout head kidney cell preparations and a trout macrophage cell line (RTS11). Trout rIL-1 beta was shown to increas e the expression level of IL-1 beta, cyclooxygenase (COX2) and MHC class II beta chain transcription, as determined by Northern blot analysis. Stimula tory doses of rIL-1 beta were typically greater than or equal to 10 ng/ml. Induction of IL-1 beta expression occurred within 1 h post-stimulation with trout rIL-1 beta and was maximal 3-6 h post-stimulation. Trout rIL-1 beta was also able to increase murine D10.G4.1 cell proliferation and trout head kidney leukocyte phagocytic activity, in a dose-dependent manner. However, equivalent D10.G4.1 cell proliferation was induced with approximately 1000 -fold lower doses of human rIL-1 beta. That LPS contamination did not contr ibute to the effects seen was confirmed by determining its concentration in the trout rIL-1 beta preparation, and demonstrating that the rIL-1 beta ac tivity was inhibited by heating or pre-incubation with a polyclonal anti-tr out rIL-1 beta antibody. (C) 2001 Elsevier Science B.V. All rights reserved .