LPS-desensitized DC exhibit reduced endocytic capacity. DC were cultured in the presence or absence of LPS at the concentrations indicated. The endocytic activity of day-5 DC was measured using FITC-DX (mannose receptor-mediated endocytosis) and FITC-BSA (macropinocytosis). The cells were incubated with FITC-DX or FITC-BSA for 30 minutes at 37°C (controls at 0°C, dotted lines), washed, and analyzed by flow cytometry.