Figure 1.

Fluorescence microscopy studies of neutrophils. (Sequence 1) A time sequence of NAD(P)H fluorescence images of a polarized neutrophil are shown. The cell's leading edge is oriented toward the top of each frame; the uropod is near the bottom. Each image was collected for 0.1 μs with a 100-ms interval between micrographs. Spatiotemporal variations in NAD(P)H intensity are shown. Fluorescent stripes appear to propagate from the uropod to the lamellipodium. FMLP was added uniformly to the sample at 50 nM. After ≈2 min, the wave undergoes splitting (frame 12). (n = 50) (magnification, ×980) Cells were also treated with a variety of biological response modifiers in rows 2–7. In row 2, cells were treated with IL-8 (50 ng/ml; n = 4) for 1 h. In rows 3 and 4, cells were exposed to immune complexes (10 μg/ml; n = 3) or PAF (10 μg/ml; n = 8) for 30 min, respectively. In row 5, cells were exposed to LTB₄ (1 mg/ml; n = 3) for 1 h. Row 6 shows cells incubated with LPS (50 ng/ml; n = 4) for 30 min. Cells were treated with the cytokine combination IFN-γ (50 units/ml, 3 h) + IL-6 (25 mg/ml, 20 min), as described in ref. 6, in row 7 (n = 4). (×960)