Identification of a potent, selective non-peptide CXCR2 antagonist that inhibits interleukin-8-induced neutrophil migration.
Interleukin-8 (IL-8) and closely related Glu-Leu-Arg (ELR) containing CXC chemokines, including growth-related oncogene (GRO)alpha, GRObeta, GROgamma, and epithelial cell-derived neutrophil-activating peptide-78 (ENA-78), are potent neutrophil chemotactic and activating peptides, which are proposed to be major mediators of inflammation. IL-8 activates neutrophils by binding to two distinct seven-transmembrane (7-TMR) G-protein coupled receptors CXCR1 (IL-8RA) and CXCR2 (IL-8RB), while GROalpha, GRObeta, GROgamma, and ENA-78 bind to and activate only CXCR2. A chemical lead, which selectively inhibited CXCR2 was discovered by high throughput screening and chemically optimized. SB 225002 (N-(2-hydroxy-4-nitrophenyl)-N'-(2-bromophenyl)urea) is the first reported potent and selective non-peptide inhibitor of a chemokine receptor. It is an antagonist of 125I-IL-8 binding to CXCR2 with an IC50 = 22 nM. SB 225002 showed >150-fold selectivity over CXCR1 and four other 7-TMRs tested. In vitro, SB 225002 potently inhibited human and rabbit neutrophil chemotaxis induced by both IL-8 and GROalpha. In vivo, SB 225002 selectively blocked IL-8-induced neutrophil margination in rabbits. The present findings suggest that CXCR2 is responsible for neutrophil chemotaxis and margination induced by IL-8. This selective antagonist will be a useful tool compound to define the role of CXCR2 in inflammatory diseases where neutrophils play a major role.
White
J R
JR
Department of Molecular Immunology, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA. john_r_white@sbphrd.com
Lee
J M
JM
Young
P R
PR
Hertzberg
R P
RP
Jurewicz
A J
AJ
Chaikin
M A
MA
Widdowson
K
K
Foley
J J
JJ
Martin
L D
LD
Griswold
D E
DE
Sarau
H M
HM
D000818:Animals; D016466:CHO Cells; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000502:physiology; D006224:Cricetinae; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors* / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects*; D010671:Phenylurea Compounds / Q000494:pharmacology*; D011817:Rabbits; D019707:Receptors, Chemokine / Q000037:antagonists & inhibitors*; D018123:Receptors, Interleukin / Q000037:antagonists & inhibitors*; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors
D016209:Interleukin-8; D010671:Phenylurea Compounds; D019707:Receptors, Chemokine; D018123:Receptors, Interleukin; D023063:Receptors, Interleukin-8B; D011994:Recombinant Proteins; C112019:SB 225002