Fig. 1.

Early down-regulation of phagocytosis in immature DCs. (A, B) FACS analysis of zymosan uptake in MØs and DCs. Cells were incubated with Texas Red zymosan at 25 particles/cell for 0.5, 1, 2, 4, and 16 h. Extracellular zymosan was removed with extensive washes with ice cold PBS. Black line: background fluorescence of cells without exposure to zymosan. Samples were also gated by size to exclude any debris or residual particles. The images show that only very few externally attached particles remained after the washes, as detected with anti-zymosan antibodies (green). Bars = 10 μm. (C) Quantification of the geometric mean fluorescence of the FACS charts shown in A and B.