Figure 2.

Dendritic cells (DCs) from endotoxin tolerant mice exhibit an increased ability for endocytosis. The in vitro ability of DCs to endocytose dextran was tested by incubating DCs with FITC-labeled dextran at a ratio of 2×10⁵ cells to 1 mg dextran for three hours. The cells were thereafter examined for endocytotic ability in two ways: (1) flow cytometry (shown in A) and (2) fluorescence microscope quantification after cytocentrifugation onto glass slides. Ten random fields were assessed per slide, and the results are presented as percentage ingestion, ie, the percentage of FITC-dextran containing cells (shown in B–D). All experiments were performed at least in triplicate. (A) Representative example of a histogram of FITC-dextran treated DCs from endotoxin tolerant mice (red line) and normal control mice (green line). (B) One representative photo taken in a fluorescence microscope of DCs from endotoxin tolerant mice. The percentage of DCs containing FITC-dextran was 59%. (C) One representative photograph of DCs from normal control mice. The percentage ingestion monitored using microscopy was 34%. (D) Statistical analysis of the data obtained from at least three separate experiments. ^bP<0.05. (B, C) ×100.