Description
The CC chemokine receptor-1 (CCR1), whose ligands include macrophage inflammatory protein-1α (MIP-1α), RANTES, and monocyte chemotactic protein-3 (MCP-3), has a central role in leukocyte trafficking and is highly expressed in certain autoimmune diseases. BX 471 is a nonpeptide CCR1 antagonist that has been shown to displace MIP-1α, RANTES, and MCP-3 with Ki values of 1, 2.8, and 5.5 nM, respectively. It demonstrates >10,000-fold selectivity for CCR1 over 28 additional G protein-coupled receptors, including related chemokine receptors. In a rat experimental allergic encephalomyelitis model of multiple sclerosis, BX 471 at 50 mg/kg was shown to significantly reduce the severity of the disease. BX 471 also decreases the inflammatory response during sepsis, blocks migration of monocytes isolated from rheumatoid arthritis patients, and prevents macrophage and T-cell recruitment in a mouse model of lupus nephritis.
Uses
BX471 has been used in chemotaxis assay to study the responses of HEK293 cells expressing human C-C motif chemokine receptor 1 (CCR1) to CC motif ligand 3 (CCL3)-induced cell migration. It has also been used as a CCR1 inhibitor to assess the effects of CCR1 on the migration and epithelial-mesenchymal transition (EMT).
Biochem/physiol Actions
BX471 blocks CCR1 and downregulates the mRNA expression of ICAM-1, P-selectin and E-selectin. It decreases the inflammatory responses in sepsis, prevents monocyte recruitment in inflammation sites in rheumatoid arthritis patients and inhibits interstitial leukocyte recruitment and fibrosis in mouse model of lupus nephritis.
in vitro
competition binding studies revealed that bx 471 was able to displace the ccr1 ligands macrophage inflammatory protein-1a, rantes, and monocyte chemotactic protein-3 with high affinity. bx 471 was a potent functional antagonist based on its ability to inhibit plenty of ccr1-mediated effects. bx 471 also demonstrated a greater than 10,000-fold selectivity for ccr1 compared with 28 g-protein-coupled receptors [1].
in vivo
pharmacokinetic studies demonstrated that bx 471 was orally active with a 60% bioavailability in dogs. furthermore, in a rat experimental allergic encephalomyelitis model of multiple sclerosis, bx 471 effectively reduces disease [1].
References
[1] liang m, mallari c, rosser m, ng hp, may k, monahan s, bauman jg, islam i, ghannam a, buckman b, shaw k, wei gp, xu w, zhao z, ho e, shen j, oanh h, subramanyam b, vergona r, taub d, dunning l, harvey s, snider rm, hesselgesser j, morrissey mm, perez hd. identification and characterization of a potent, selective, and orally active antagonist of the cc chemokine receptor-1. j biol chem. 2000 jun 23;275(25):19000-8.
