Interference with heparin binding and oligomerization creates a novel anti-inflammatory strategy targeting the chemokine system.
A hallmark of autoimmunity and other chronic diseases is the overexpression of chemokines resulting in a detrimental local accumulation of proinflammatory immune cells. Chemokines play a pivotal role in cellular recruitment through interactions with both cell surface receptors and glycosaminoglycans (GAGs). Anti-inflammatory strategies aimed at neutralizing the chemokine system have to-date targeted inhibition of the receptor-ligand interaction with receptor antagonists. In this study, we describe a novel strategy to modulate the inflammatory process in vivo through mutation of the essential heparin-binding site of a proinflammatory chemokine, which abrogates the ability of the protein to form higher-order oligomers, but retains receptor activation. Using well-established protocols to induce inflammatory cell recruitment into the peritoneal cavity, bronchoalveolar air spaces, and CNS in mice, this non-GAG binding variant of RANTES/CCL5 designated [44AANA47]-RANTES demonstrated potent inhibitory capacity. Through a combination of techniques in vitro and in vivo, [44AANA47]-RANTES appears to act as a dominant-negative inhibitor for endogenous RANTES, thereby impairing cellular recruitment, not through a mechanism of desensitization. [44AANA47]-RANTES is unable to form higher-order oligomers (necessary for the biological activity of RANTES in vivo) and importantly forms nonfunctional heterodimers with the parent chemokine, RANTES. Therefore, although retaining receptor-binding capacity, altering the GAG-associated interactive site of a proinflammatory chemokine renders it a dominant-negative inhibitor, suggesting a powerful novel approach to generate disease-modifying anti-inflammatory reagents.
Johnson
Zoë
Z
Serono Pharmaceutical Research Institute, Geneva, Switzerland.
Kosco-Vilbois
Marie H
MH
Herren
Suzanne
S
Cirillo
Rocco
R
Muzio
Valeria
V
Zaratin
Paola
P
Carbonatto
Michela
M
Mack
Matthias
M
Smailbegovic
Amir
A
Rose
Mark
M
Lever
Rebecca
R
Page
Clive
C
Wells
Timothy N C
TN
Proudfoot
Amanda E I
AE
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics / Q000276:immunology; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D002464:Cell Migration Inhibition; D018946:Chemokine CCL5 / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D003888:Desensitization, Immunologic; D005260:Female; D006493:Heparin / Q000378:metabolism*; D006801:Humans; D018836:Inflammation Mediators / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D007962:Leukocytes / Q000166:cytology / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018715:Microscopy, Video; D009154:Mutation; D010537:Peritoneum / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D000894:Anti-Inflammatory Agents, Non-Steroidal; D018946:Chemokine CCL5; D018836:Inflammation Mediators; D006493:Heparin