Analysis of TfR protein and surface expression in cytokine-activated THP-1 cells.

THP-1 cells were treated as described in the legend to Figure 1. Cells were then either subjected to preparation of protein extracts for Western blot analysis (top panel) or used for quantification of cell surface expression of TfR by means of FACS as described in “Materials and methods.” Shown is 1 of 3 representative Western blot experiments. The figures in FACS analysis represent the geometric mean log fluorescence minus isotype and reagent control from 1 of 3 experiments performed in duplicate. *P < .05 compared with the unstimulated control as calculated by Student ttest when comparing the means of all 3 experiments.