Autologous iris pigment epithelial cell transplantation in monkey subretinal region

To establish autologous iris pigment epithelial (IPE) cell transplantation in monkey eyes.

Autologous IPE cells from three monkeys were obtained by peripheral iridectomy, and cell culture was performed with autologous serum. The cultured cells were labeled with DiI, and transplantation was performed by transvitreal approach to the submacular region of each monkey. Fundus examination, photography, and fluorescein angiography were performed monthly. Histochemical analysis and electron microscopy were also performed six months after transplantation.

Auto IPE cells grew well in auto serum. No fluorescein leakage or retinal thickening was observed after submacular transplantation. We demonstrated the presence of autologous IPE cells in the region 6 months after transplantation by histologic and electron microscopic examination. Electron microscopy also demonstrated that the transplanted cells appeared to be less pigmented and to have less mitochondria than did the host retinal pigment epithelial cells. However, some transplanted cells looked as if they embrace the photoreceptor outer segments.

Autologous IPE cell culture of the monkey was established using auto serum. Six months after transplantation of the cultured IPE cells, we could still observe the cells in the region. This method may have potential use in human disease that requires autologous cell transplantation to prevent host-graft rejection, and to provide an alternative substance that functions like retinal pigment epithelium.