The unique target specificity of a nonpeptide chemokine receptor antagonist: selective blockade of two Th1 chemokine receptors CCR5 and CXCR3

Abstract

CC chemokine receptor (CCR) 5 and CXC chemokine receptor (CXCR)3 are expressed on T helper cell type 1 cells and have been implicated in their migration to sites of inflammation. Our preceding study demonstrated that a nonpeptide synthetic CCR5 antagonist, TAK-779 (N, N-dimethyl-N-[4-[[[2-(4-methylphenyl)-6, 7-dihydro-5H-benzocyclohepten-8-yl]carbon-yl]amino]benzyl]-tetrahydro-2H-pyran4-aminium chloride, inhibits the development of experimentally induced arthritis by modulating the migration of CCR5(+)/CXCR3(+) T cells to joints. The present study investigated the functional properties of TAK-779, including the effect of this antagonist on CXCR3 function. For this purpose, transfectants expressing mouse CCR5 (mCCR5) or mCXCR3 and expressing mCCR4 or mCXCR4 as controls were established by introducing each relevant gene into 2B4 T cells and were subjected to the following assays. First, the ligand binding to chemokine receptors was assayed by incubating transfectants with [(125)I]-labeled relevant ligand or with the unlabeled relevant ligand followed by staining with anti-ligand antibody. Second, chemokine-induced lymphocyte function-associated antigen-1 (LFA-1) activation was assayed by measuring the adhesion of cells to microculture plates coated with purified intercellular adhesion molecule-1. Third, chemokine-stimulated chemotaxis was assayed by observing the cell migration through transwells. In these assays, TAK-779 blocked the ligand binding as well as LFA-1 up-regulating and chemotactic function of mCXCR3 and mCCR5 but did not elicit a biologically significant inhibition of those functions of mCCR4 and mCXCR4. These observations indicate the unique target specificity of TAK-779 and explain why this antagonist efficiently blocks the migration of T cells expressing CCR5 and CXCR3 to sites of inflammation.

Chemokines and their receptors in rheumatoid arthritis: Future targets?

“…A CCR5 nonpeptide antagonist, when used preventively, inhibited mouse CIA and migration of leukocytes to the joints (115). This inhibitor, however, also blocked binding of ligand to CXCR3, making it difficult to determine its precise mechanism (116). KE-298 (2-acetylthiolmethyl-4-[4-methylphenyl]-4-oxobutanoic acid), an antirheumatic drug, reduced MCP-1/CCL2 and RANTES/CCL5 production and also reduced the severity of rat AIA (117).…”

Pharmacological Characterization of CXC Chemokine Receptor 3 Ligands and a Small Molecule Antagonist

“…Nonpeptide small molecule antagonists have been shown to interact with chemokine receptors, including CXCR3. For example, the CCR5 small molecule antagonist N, N-dimethyl-N-[4-[[[2-(4-methylphenyl)-6,7-dihydro-5H-benzocyclohepten-8-yl]carbonyl]amino]benzyl]tetrahydro-2H-pyran-4-aminium chloride (TAK779), also binds to murine, but not human, CXCR3 with high affinity and is effective in reducing severity and incidence of collageninduced arthritis in the DBA/1 mouse model (Yang et al, 2002;Gao et al, 2003). These proof-of-concept experiments have led to the development of specific small molecule antagonists for CXCR3, and one such compound (T487) is currently being developed for psoriasis and RA by ChemoCentryx, Inc. (Mountain View, CA) in collaboration with Tularik/Amgen Biologicals (Thousand Oaks, CA) (Medina and Johnson, 2002;Medina et al, 2004).…”

Opposing Roles for CXCR3 Signaling in Central Nervous System Versus Ocular Inflammation Mediated by the Astrocyte-Targeted Production of IL-12

“…Within the CNS of these mice with CXCR3 deficiency, we observed a markedly attenuated inflammatory response, which corresponded with the well-characterized impact of the CXCR3 chemokine system on the migration and attraction of type 1 immune cells. 38,39 Unexpectedly, these same animals developed a very severe inflammatory disease of the eyes, demonstrating that the effect of CXCR3 in neuroinflammation is not only dependent on the underlying cause but also strongly influenced by the site of the inflammation.…”