Antagonist activity against human CCR2B expressed in Chem-1 cells assessed as inhibition of human CCL2-induced intracellular calcium flux incubated for 10 mins by Fluo-4 AM dye based intracellular calcium flux assay
Radioligand Binding Assay: Radioligand binding assays were performed in CHO cells expressing human CCR2B and Galpha±16 coupling protein. All compounds were dissolved in DMSO and assays run at a final DMSO concentration of 0.5% (v/v). [125I]-labeled human MCP-1 was purchased from PerkinElmer. Unlabelled human MCP-1 was purchased from PeproTech.Compounds were serially diluted in DMSO before diluting into assay buffer (25 mM HEPES, pH 7.4, 5 mM MgCl2, 1 mM CaCl2, 0.5% BSA) with cryo preserved CHO cells expressing human CCR2B and the Galpha±16 coupling protein (30x103/well) and [125I]-MCP-1 (50 pM). The reaction was incubated at room temperature for 90 minutes before transferring to GF/C filter membrane (PerkinElmer) pre-treated with 0.3% polyethyleneimine for 2 hours at 4 C. The filter membrane was washed six times with ice cold wash buffer (25 mM HEPES, pH 7.4, 5 mM MgCl2, 1 mM CaCl2, 500 mM NaCl, 0.01% (m/v) azide), dried, and sealed in a RLB sample bag (Agilent Technologies).
Binding Assay: THP-1 (cells were incubated with 0.5 nM 125I labeled MCP-1 (Perkin-Elmer Life Sciences, Inc. Boston, Mass.) in the presence of varying concentrations of either unlabeled MCP-1 (R & D Systems, Minneapolis, Minn.) or test compound for 2 hours at 30° C. in a 96 well plate. Cells were then harvested onto a filter plate, dried, and 20 μL of Microscint 20 was added to each well. Plates were counted in a TopCount NXT, Microplate Scintillation & Luminescence Counter (Perkin-Elmer Life Sciences, Inc. Boston, Mass.). Blank values (buffer only) were subtracted from all values and drug treated values were compared to vehicle treated values. 1 μM cold MCP-1 was used for nonspecific binding.
Binding Assay: MCP-1 Receptor Binding Assay in THP-1 Cells Human monocytic cell line THP-1 cells were obtained from American Type Culture Collection (Manassas, Va., USA). The THP-1 cells were grown in RPMI-1640 (RPMI: Roswell Park Memorial Institute Medium-cell culture growth media) supplemented with 10% fetal bovine serum in a humidified 5% CO2 atmosphere at 37 C. The cell density was maintained between 0.5x106 cells/mL.THP-1 (cells were incubated with 0.5 nM 125I labeled MCP-1 (Perkin-Elmer Life Sciences, Inc. Boston, Mass.) in the presence of varying concentrations of either unlabeled MCP-1 (R & D Systems, Minneapolis, Minn.) or test compound for 2 hours at 30 C. in a 96 well plate. Cells were then harvested onto a filter plate, dried, and 20 uL of Microscint 20 was added to each well. Plates were counted in a TopCount NXT, Microplate Scintillation & Luminescence Counter (Perkin-Elmer Life Sciences, Inc. Boston, Mass.).
Antagonist activity at human C-C chemokine receptor type 2 expressed in THP-1 cells assessed as inhibition of CCL2-induced calcium flux preincubated for 10 mins followed by CCL2 addition by Fluo-4 dye based FLIPR assay
Displacement of [125I]MCP-1 from human recombinant CCR2 expressed in HEK293 cells assessed as remaining radioligand binding at 10 uM after 60 mins by scintillation counting method relative to control