Figure 3.

Ensheathment by Human RPE Is Specific for POS

(A) A schematic of the experiment. HESC-RPE cells were primed with 30% serum for 1 h before addition of F-POS or latex beads. Control cells were either left untreated or treated with beads without serum. Cells were incubated for 3 h at 37°C. All samples were washed after 3 h. Some samples were fixed and others were kept for 3 h or more to allow internalization of beads. Samples were analyzed with SEM or TEM.

(B) SEM image of RPE cells treated with beads (artificially colored yellow) for 3 h. Scale bar, 1 μm.

(C) TEM image at 6 h. Beads (dashed purple line) were observed inside the cells and close to the nuclei.

(D) TEM image at 3 h. Beads were observed either at the surface of the cell (dashed orange line), or getting internalized by the RPE (dashed purple line). In both SEM and TEM analyses, no sheets were observed around the beads.