Surface myeloid inhibitory C-type lectin-like receptor (MICL) expression is significantly decreased upon activation of human neutrophils with monosodium urate crystals (MSU). The plasma membrane expression of MICL was examined by flow cytometry on freshly isolated neutrophils (10 × 106 cells/ml) after incubation at 37°C with (A) MSU (1 mg/ml) for 20 min, (B) nonopsonized zymosan (z) (ratio = 10 z/cell), lipopolysaccharide (LPS) (22.5 ng/ml in 1× Hanks' balanced salt solution containing 5% decomplemented fetal bovine serum), tumor necrosis factor α (TNF-α; 100 U/ml), granulocyte-macrophage colony-stimulating factor (80 nM), granulocyte colony-stimulating factor (50 ng/ml) or platelet-activating factor (10−6 M) for 15 min or (C) the 50C1 antibody (1 µg/ml) or IgG2a isotype control antibody for 5 min or 20 min as described in Methods. MICL expression was compared to the control. The raw flow cytometry data in (A) is shown in the right panel. These graphs are compilations from four independent experiments.