Species selectivity of a small molecule antagonist for the CCR1 chemokine receptor
Introduction
The chemokines are a group of small proteins that play an important role in leukocyte-trafficking during immune response Schall, 1994, Baggiolini, 1998. They can be classified into four groups, CC, CXC, C, and CX3C, according to the positions of the cysteines at the N-terminus of the molecule (Schall, 1994). The chemokines produce their biological effects by activating specific receptor proteins on their target cells (Horuk, 1994). To date, a total of 16 chemokine receptors, including nine CC chemokine receptors and five CXC chemokine receptors, have been identified Mackay, 1996, Luster, 1998. All of these receptors belong to a G-protein-coupled receptor superfamily (Dohlman et al., 1991).
Chemokines have been implicated in the pathogenesis of chronic inflammatory diseases, such as multiple sclerosis and rheumatoid arthritis. For example, expression of RANTES and macrophage inflammatory protein-1α (MIP-1α) correlated with the disease onset in a mouse experimental autoimmune encephalomyelitis model of multiple sclerosis (Godiska et al., 1995). A recent study by Karpus et al. (1995) demonstrated that antibodies to MIP-1α prevented the development of both acute and relapsing paralytic disease as well as infiltration of mononuclear cells into the central nervous system. Treatment with MIP-1α antibody was also able to ameliorate the severity of ongoing clinical disease. These results led the authors to conclude that MIP-1α plays an important role in this T-cell-mediated disease.
A number of studies have also suggested a role for RANTES in rheumatoid arthritis. Both RANTES mRNA and protein appear to be upregulated in rheumatoid arthritis Rathanaswami et al., 1993, Snowden et al., 1994. Antibodies against RANTES significantly decreased the severity of ongoing clinical disease in a rat adjuvant-induced rheumatoid arthritis model (Barnes et al., 1998).
These studies provided strong evidence for an important role of the chemokines, RANTES, and MIP-1α in chronic inflammatory diseases. Since MIP-1α and RANTES are ligands for CCR1, antagonists for this receptor may prove to be useful in treatment of these diseases. In our previous report, we identified a novel series of small molecule antagonists for human CCR1 receptor. In this study, we further characterize the pharmacological properties of one of these compounds, 2-2-diphenyl-5-(4-chlorophenyl)piperidin-1-yl)valeronitrile (CCR1 antagonist 1), report the cloning of CCR1 receptor from marmoset and rabbit, and discuss the selectivity of CCR1 antagonist 1 for CCR1 receptors from a number of animal species. The study will provide useful information for testing the efficacy of CCR1 antagonists in animal disease models in vivo.
Section snippets
Materials
Unlabeled chemokines were from Peprotech (Rocky Hill, NJ). 125I-labeled chemokines were obtained from New England Nuclear (Boston, MA).
Synthesis of compounds
CCR1 antagonist 1 was synthesized as previously described (Hesselgesser et al., 1998).
Marmoset CCR1 gene cloning
Previous studies had shown that the mouse and human CCR1 genes are highly conserved and contain no introns Gao et al., 1993, Neote et al., 1993. A number of polymerase chain reaction (PCR) primers were synthesized based on the 5′ and 3′ ends of the human coding region. In
Cloning of CCR1 receptors from rabbit and marmoset
We have previously identified and described a novel CCR1 antagonist, (2-2-diphenyl-5-(4-chlorophenyl)piperidin-1-yl)valeronitrile), designated CCR1 antagonist 1. In order to examine the species selectivity of this antagonist, CCR1 receptors were cloned from rabbit and marmoset. As expected, these receptors were highly homologous (Table 1 and Fig. 1). However, as shown in Fig. 1, the rabbit receptor is missing 12 nucleotides corresponding to four amino acids in the cytoplasmic tail region of the
Discussion
CCR1 could be a therapeutic target for autoimmune diseases like multiple sclerosis and rheumatoid arthritis since its ligands, MIP-1α and RANTES, have been implicated in these diseases Karpus and Kennedy, 1997, Karpus et al., 1995, Plater-Zyberk et al., 1997, Barnes et al., 1998. Thus, a potent and selective CCR1 antagonist could be useful as a potential therapy. We have previously identified and described a novel CCR1 antagonist, CCR1 antagonist 1 (Hesselgesser et al., 1998). This compound was
References (27)
- et al.
Identification of residues responsible for the selective binding of peptide antagonists and agonists in the V2 vasopressin receptor
J. Biol. Chem.
(1998) - et al.
Molecular basis for the species selectivity of the neurokinin-1 receptor antagonists, CP-96,345 and RP67580
J. Biol. Chem.
(1992) - et al.
Cloning and differential tissue-specific expression of three mouse{beta} chemokine receptor-like genes, including the gene for a functional macrophage inflammatory protein-1{alpha} receptor
J. Biol. Chem.
(1995) - et al.
Chemokine expression in murine experimental allergic encephalomyelitis
J. Neuroimmunol.
(1995) - et al.
Identification and characterization of small molecule functional antagonists of the CCR1 chemokine receptor
J. Biol. Chem.
(1998) Molecular properties of the chemokine receptor family
Trends Pharmacol. Sci.
(1994)- et al.
Molecular cloning, functional expression, and signaling characteristics of a CC chemokine receptor
Cell
(1993) - et al.
The N-terminal extracellular segments of the chemokine receptors, CCR1 and CCR3, are determinants for MIP-1alpha and eotaxin binding, respectively, but a second domain is essential for efficient receptor activation
J. Biol. Chem.
(1998) - et al.
Human formyl peptide receptor ligand binding domain(s). Studies using an improved mutagenesis/expression vector reveal a novel mechanism for the regulation of receptor occupancy
J. Biol. Chem.
(1994) - et al.
Effect of a CC chemokine receptor antagonist on collagen-induced arthritis in DBA/1 mice
Immunol. Lett.
(1997)
Expression of the cytokine, RANTES, in human rheumatoid synovial fibroblasts
J. Biol. Chem.
RANTES role in rheumatoid arthritis
Lancet
Some quantitative uses of drug antagonists
Br. J. Pharmacol.
Cited by (0)
- 1
Current address: Coulter Pharmaceutical, South San Francisco, CA 94080, USA.