FIG. 5.

Cell surface expression of neutrophil IL-3Rα. Freshly isolated neutrophils were stained with anti-IL-3Rα or isotype control antibodies and examined by flow cytometry (A). Neutrophils were also incubated for 18 h with conditioned medium from uninfected fibroblasts (B), 600 pg of GM-CSF/ml (C), or conditioned medium from infected fibroblasts preincubated for 1 h with 1 μg of isotype control antibody/ml (D) or 1 μg of anti-GM-CSF/ml (E) and then stained. Stained neutrophils were gated for viable cells by forward and side scatter criteria. Results are expressed as histograms of the fluorescence intensity of the viable cell population and are representative of two experiments. …., isotype control antibody; ___, anti-IL-3Rα.