Fig. 3

Comparison of differentiated PLB-985 cells with primary neutrophils. a Undifferentiated PLB-985 cells, PLB-985 cells differentiated with DMSO and Nutridoma, and primary neutrophils were stained with antibody against CD11b and analyzed by cytometry. Staining of primary neutrophils with an isotype control antibody is also shown. b The same cell samples were stained with FLPEP and analyzed by cytometry. Unstained samples are also shown for comparison. c Phagocytosis of pHrodo Green-labeled dead Staphylococcus aureus bioparticles. Negative controls in which no particles were present are also shown. d-f Differentiated PLB-985 cells and primary neutrophils were plated under agarose and analyzed in an automated chemotaxis assay by time-lapse microscopy with chemoattractant uncaging of Nv-fMLF. Mean cell speed was measured both before (d) and after (e) generation of an fMLF gradient. A cell directionality parameter measuring the angular bias of cell movement towards the gradient source is shown (f). An angular bias of 90 degrees indicates perfect directionality, and zero degrees indicates random orientation. This experiment was performed three times. Error bars represent the standard error of the mean. Asterisk indicates a p-value of less than 0.05 and double asterisks indicate a p-value of less than 0.01 using a t-test. g Histograms of the instantaneous directionality of individual cells is shown for the same experiments analyzed in (f). Here an angle of zero indicates optimal directionality, and 180 degrees indicates movement in the opposite direction. A third curve (yellow) indicates simulated data for a population of neutrophils in which only 70% of cells express the receptor FPR1