ANTI-IL-1 ACTIVITY OF PEPTIDE-FRAGMENTS OF IL-1 FAMILY PROTEINS

A series of peptides containing retro-tuftsin-and tuftsin-like motifs from IL-1 proteins inhibits IL-l-induced IL-2 production and reduces t he humoral immune response, thus supporting our hypothesis that tuftsi n (Thr-Lys-Pro-Arg)-IL-1 competition depends on the presence of such m otifs in IL-1 proteins. Some other peptides from regions of IL-1 respo nsible for receptor binding were also active, with peptide Ile-Thr-Gly -Ser-Glu (III) from IL-1 alpha (residues 98-102), not only strongly af fecting IL-2 production, but also suppressing the immune response; the analogue of hexapeptide Val-Thr-Lys-Phe-Tyr-Phe from the C-terminal p art of IL-1ra, with Lys replaced by Asp, was as efficient as Val-Thr-L ys-Phe-Tyr-Phe with respect to IL-1 competition. (C) 1998 Elsevier Sci ence Inc.