PHAGOCYTIC-ACTIVITY OF CULTURED RETINAL-PIGMENT EPITHELIUM - UPTAKE OF POLYSTYRENE SPHERES AND STAPHYLOCOCCUS-AUREUS

Phagocytosis of the chick embryo retinal pigment epithelial (RPE) cells in cultures was examined morphologically. All spheres such as native and glutaraldehyde-fixed Staphylococcus aureus (S. aureus) inoculated to the RPE cell cultures were actively phagocytized as well as polystyrene latex particles (PS). There was no significant difference in uptake rate between PS and fixed bacteria, although native bacteria were taken up at a somewhat higher level than the other spheres, at least up to 90 min after inoculation. Intracytoplasmic multiplication of native bacteria did not occur up to this early stage of inoculation, but after 20 hr, the delayed growth in the RPE cells was observed. In many phagosomes containing native bacteria, a characteristic membrane configuration which was apparently continuous with rough surfaced endoplasmic reticulum of the RPE cells was seen. On the contrary, these structures were never encountered in the phagosomes containing PS and fixed bacteria. © 1979.