Fig. 3

Phagocytosis in mCD33^+/+ and mCD33^−/− cultured macrophages and microglia. a, b Abrogated expression of mCD33 expression in a RAW264.7, b BV-2 cells by flow cytometry. c–f Flow cytometry-based analysis of c dextran particles, d polystyrene beads, e myelin, f, and aggregated Aβ_1-42 in mCD33^+/+ (black; six independent clones) and mCD33^−/− (red; nine independent clones) RAW264.7 cells. For each cargo, a representative flow cytometry data and summary plots for each clone, where each data point represents the average of at least three replicates for each clone. Note that for the polystyrene beads, cells incubated without beads are not shown as they overlay directly under the major peak on the left, which represent cells that have not taken up the beads. Statistical significance calculated based on an unpaired Student’s T-test. g–i Microscopy-based analysis of polystyrene bead uptake in mCD33^+/+ (n = 4 independent clones) and mCD33^−/− (n = 8 independent clones) RAW264.7 clones. g Representative image of cells imaged following uptake (red = Calcein, blue = polystyrene bead). h Results for a single experiment where results for each clone are average for three different wells. i Summary of five independent experiments setting the average levels in the WT clones to 100%; N.S. represents no statistical significance based on a paired Student’s T-test. j, k Phagocytosis of polystyrene beads (j) and aggregated Aβ_1-42 (k) in mCD33^+/+ (black; six independent clones) and mCD33^−/− (red; six independent clones) BV-2 cells in the absence and presence of 10 μM Cytochalasin-D. Statistical significance calculated based on an unpaired Student’s T-test.