Rainbow trout (Oncorhynchus mykiss) recombinant IL-1 beta and derived peptides induce migration of head-kidney leucocytes in vitro

The present work provides the first information concerning the chemoattract ant activity of trout recombinant IL-1 beta and its derived peptides, refer red to as P1, P2 and P3. The predicted rainbow trout mature interleukin-1 b eta peptide was produced as a recombinant protein in Escherichia coh. The f irst peptide, P1, corresponded to fragment 146-157 (YVTPVPIETEAR) of the tr out sequence and had an MW of 1.37 kDa. It was equivalent to a region known to be part of the receptor binding domain from the mammalian crystal struc ture of IL-1 beta complexed to its receptor. P2 was used as control peptide , consisting of the same 12 amino acids as P1, but arranged in a random seq uence (VVEEYIRAPPTT). P3 was synthesised to complex with an adjacent region of the IL-1 receptor, and corresponded to fragment 207-216 (YRRNTGVDIS) of the trout sequence, with an MW of 1.18 kDa. Migration was stimulated when leucocytes were exposed to concentrations of greater than or equal to 10 ng ml(-1) rIL-1 beta. Peptide P3 also induced leucocyte migration, with an op timal dose of 0.25 mm being recorded. While P1 had no effect on cell migrat ion when used alone, synergism was evident as a consequence of combining P1 with a suboptimal dose (0.01 mm) of P3. No synergism occurred when cells w ere exposed to a combination of P3 and the control peptide P2. (C) 2001 Aca demic Press.