FIGURE 3.

Endocytosis of radiolabeled ligands mediated by uPARAP, MR, PLA₂R, and DEC-205. HEK-293T cells were transfected with uPARAP (A), MR (B), PLA₂R (C), and DEC-205 (D). In each panel, black columns show the internalization of a radiolabeled positive control ligand (left), collagen type I (center) and collagen type IV (right), with mock transfected cells shown for comparison (gray columns). Cells were incubated with radiolabeled ligands (100 ng/ml) for 4 h after which the fraction of intracellular ligand was determined. Positive control ligands were anti-uPARAP mAb (2h9), mannose-BSA, porcine pancreatic PLA₂, and anti-DEC-205 mAb, for uPARAP, MR, PLA₂R, and DEC-205, respectively. Data are presented as radioactive ligand in the intracellular fraction in percent of the total radioactive ligand added to cells. Error bars represent S.D. of triplicate samples.