Anti‐inflammatory therapy by intravenous delivery of non‐heparan sulfate‐binding CXCL12

Abstract

Interaction between chemokines and heparan sulfate (HS) is essential for leukocyte recruitment during inflammation. Previous studies have shown that a non-HS-binding mutant form of the inflammatory chemokine CCL7 can block inflammation produced by wild-type chemokines. This study examined the anti-inflammatory mechanism of a non-HS-binding mutant of the homeostatic chemokine CXCL12. Initial experiments demonstrated that mutant CXCL12 was an effective CXCR4 agonist. However, this mutant chemokine failed to promote transendothelial migration in vitro and inhibited the haptotactic response to wild-type CCL7, CXCL12, and CXCL8, and naturally occurring chemoattractants in synovial fluid from the rheumatoid synovium, including CCL2, CCL7, and CXCL8. Notably, intravenous administration of mutant CXCL12 also inhibited the recruitment of leukocytes to murine air pouches filled with wild-type CXCL12. Following intravenous administration, wild-type CXCL12 was cleared from the circulation rapidly, while the mutant chemokine persisted for >24 h. Chronic exposure to mutant CXCL12 in the circulation reduced leukocyte-surface expression of CXCR4, reduced the chemotactic response of these cells to CXCL12, and inhibited normal chemokine-mediated induction of adhesion between the ␣4␤1 integrin, VLA-4, and VCAM-1. These data demonstrate that systemic administration of non-HS-binding variants of CXCL12 can mediate a powerful anti-inflammatory effect through chemokine receptor desensitization.-O'Boyle, G., Mellor, P., Kirby, J. A., Ali, S. Anti-inflammatory therapy by intravenous delivery of non-heparan sulfate-binding CXCL12. FASEB J. 23, 3906 -3916 (2009). www.fasebj.org

Chemokine (C-X-C Motif) Receptor 4 and Atypical Chemokine Receptor 3 Regulate Vascular α1-Adrenergic Receptor Function

“…As expected (19,21,(45)(46)(47) Next, we studied the effects of the CXCR4 and ACKR3 ligands that did not influence normal blood pressure in a hemorrhagic shock model. This model consisted of 30 min hemorrhage to a mean arterial blood pressure (MAP) of 30 mmHg followed by crystalloid fluid resuscitation to a MAP of 70 mmHg.…”

Homeostatic and Tissue Reparation Defaults in Mice Carrying Selective Genetic Invalidation of CXCL12/Proteoglycan Interactions

“…[11][12][13][14][15] K24S and K25S point mutations were introduced in the critical HSbinding domain (encoded in the second exon) shared by the 3 CXCL12 isoforms ( Figure IIA in the online-only Data Supplement). Furthermore, a nonsense amber mutation was introduced in the fourth exon to prevent the translation of the distinctive 30 last Aa of the highly cationic C-ter domain of CXCL12␥ ( Figure IA in the online-only Data Supplement).…”

“…12 We reported previously that neutralization of the K24H25L26K27 cationic charge (K24S and K27S substitutions) is sufficient to drastically reduce binding to HS and complexing of CXCL12␣ with either immobilized heparin or HS. [11][12][13][14] Similarly, O'Boyle et al 15 recently reported that combined K24S and K27S in CXCL12␤ are sufficient to impede HS binding of this isoform on the apical surface of endothelial cells and promote a dramatic blood and delayed clearance compared with the wild-type (WT) counterpart. To abrogate HS binding of CXCL12␥, the mutation of K24H25L26K27 combined with the C-ter 4 -overlapping BBXB motifs is required.…”

“…12,13 Of note, although all these HS-binding CXCL12 mutants show a preserved global structure defined by nuclear magnetic resonance 11,12 and are full CXCR4 agonists in vitro, 10 -13,15 they have only a marginal capacity to attract leukocytes or endothelial progenitor cells in vivo and are unable to immobilize and localize properly on GAG structures. 13,15 Importantly, CXCL12 HS-binding mutants induce homologous CXCR4 desensitization, thus neutralizing the chemoattractant properties of CXCL12 WT molecules. 15 CXCL12 binds both CXCR4 and CXCR7, 16 -19 is the only cognate ligand of CXCR4, and plays essential and nonredundant roles in organogenesis.…”

“…13,15 Importantly, CXCL12 HS-binding mutants induce homologous CXCR4 desensitization, thus neutralizing the chemoattractant properties of CXCL12 WT molecules. 15 CXCL12 binds both CXCR4 and CXCR7, 16 -19 is the only cognate ligand of CXCR4, and plays essential and nonredundant roles in organogenesis. 20,21 CXCL12 is widely expressed by mesothelial cells, epithelial cells, endothelial cells, and osteoblasts, as well as bone marrow (BM) stromal cells.…”