Immunophagocytic properties of retinal pigment epithelium cells.

Retinal pigment cells were dislodged from normal monkey eyes and incubated in glass-slide chambers. All viable pigment cells adhered strongly to glass. They demonstrated surface receptors for the Fc portion of immunoglobulin G and for the third component of complement by selectively binding and phagocytizing antibody or complement-coated erythrocytes. These phagocytic cells with receptors were identified as retinal pigment cells by characteristic ultrastructural features. Thus, retinal pigment cells, which are generally believed to be derived from neural tissue, are not only scavengers of photoreceptor cell debris, but also have surface receptors and phagocytic functions that may be important in ocular defense.