Abstract
Purpose::
A spontaneously arising cell line (B6-RPE07) has been cloned from a primary culture of mouse retinal pigment epithelial (RPE) cells and has been subcultured for more than 18 months (>120 passages). The morphological and functional properties of this cell line in the context of the mouse RPE cell in vivo have been characterized.
Methods::
The morphology of the B6-RPE07 cells was examined by phase-contrast light microscopy, electron microscopy and confocal microscopy of immuno-stained cultures. Barrier properties of B6-RPE07 cells was measured by the flux of fluorescence form the apical to the basolateral compartment in transwell cell culture chambers. The abilities of the cells to bind and phagocytose photoreceptor outer segments were determined by confocal microscopy as well as electron microscopy. Cytokine/chemokine secretion by B6-RPE cells was determined by cytokine-beads-assay (CBA).
Results::
B6-RPE07 cells present a typical epithelial cobblestone morphology on uncoated, laminin-coated or collagen-coated culture dishes. All cells express pan cytokeratin, a characteristic of epithelial cells. Microvilli were observed on the apical surface of the cells by transmission electro-microscopy (TEM), as well tight junctions. Tight junction protein ZO-1 was detected by confocal microscopy. B6-RPE07 cells also exhibit phagocytic activity. The CBA assay indicated that B-RPE07 cells secrete high levels of IL-6(4053 pg/µg protein in supernatants), and MCP-1(14410pg/µg protein in supernatants), moderate levels of IL-10(17pg/µg protein in supernatants), and low levels of IFN-γ (1.5pg/µg protein in supernatants).
Conclusions::
This is the first reported mouse RPE cell line with the morphological and functional characteristics mouse RPE cells in vivo. It should prove useful for RPE studies, in particular for in vivo gene modification and transplantation studies.
Keywords: retinal pigment epithelium • photoreceptors • retinal degenerations: cell biology