Interleukin-8 antagonists generated by N-terminal modification.
We have previously shown that the residues Glu4-Leu5-Arg6 (ELR) preceding the first cysteine at the N terminus of the 72-residue form of interleukin-8 (IL-8) are essential for receptor binding and neutrophil activation (Clark-Lewis, I., Schumacher, C., Baggiolini, M., and Moser, B. (1991) J. Biol. Chem. 266, 23128-23134). We have now synthesized a series of analogs of IL-8(4-72), the truncated form of IL-8 with the N-terminal sequence ELRC, as potential IL-8 antagonists. Among 26 analogs with deletions or amino acid replacements in the ELR region several inhibited IL-8 function. The most potent were IL-8(6-72), with Arg6 at the N terminus, and IL-8,AAR(7-72) with N-terminal Ala4-Ala5 instead of Glu4-Leu5. They inhibited IL-8 receptor binding, exocytosis (IC50 0.3 microM), as well as chemotaxis and the respiratory burst. Inhibition was restricted to responses elicited by IL-8, GRO alpha, or NAP-2, and no effect was observed when the unrelated agonists fMet-Leu-Phe or C5a were used as stimuli. These results demonstrate that selective antagonists that prevent or attenuate the action of IL-8 and its related chemotactic cytokines are obtained by modification of the ELR sequence at the N terminus.
Moser
B
B
Theodor-Kocher Institute, University of Bern, Switzerland.
Dewald
B
B
Barella
L
L
Schumacher
C
C
Baggiolini
M
M
Clark-Lewis
I
I
D000595:Amino Acid Sequence; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors* / Q000737:chemistry; D008969:Molecular Sequence Data; D009504:Neutrophils / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors; D023062:Receptors, Interleukin-8A
D016209:Interleukin-8; D011971:Receptors, Immunologic; D023062:Receptors, Interleukin-8A