MICL modulates MSU-induced calcium mobilization in human neutrophils. (A) Human neutrophils (10 × 106 cells/ml) were preincubated with Fura-2AM (1 µM) for 30 min at 37°C. The extracellular probe was removed by washing in HBSS, and the cells were resuspended at 5 × 106 cells/ml. Anti-MICL antibody (clone 50C1, 2 μg/ml) or IgG2a isotype was added for 5 min. Cells were transferred to a thermostat-controlled (37°C) cuvette compartment of an SLM 8000 spectrofluorometer. Calcium mobilization was measured following the addition of 1 mg/ml MSU at 37°C. Fluorescence was monitored at an excitation wavelength of 340 nm and an emission wavelength of 510 nm. The internal calcium concentrations were calculated as described by Grynkiewicz et al. . This result is representative of four independent experiments.