Study: Immune-matched Stem Cells Prevent Rejection of Retinal Transplants in Animals

Stem cell-based transplantation approaches hold great potential for treating a wide range of eye diseases, but progress has been limited by concerns about cost, safety, and effectiveness.

In two related studies published RECENTLY in Stem Cell Reports, the journal of the International Society for Stem Cell Research (ISSCR), scientists in Japan overcame a part of these concerns by demonstrating the successful transplantation of stem cell-derived retinal cells generated from immunologically matched donor animals without the need for harmful immunosuppressants.

"Our findings address a major controversy in the stem cell transplantation field by showing that retinal cell grafts are attacked by the immune system if the donor and recipient are not immune-matched, and that matching prevents immune attacks against the grafts without the need for immunosuppressants," says first author Sunao Sugita of the RIKEN Center for Developmental Biology. "This approach could potentially be used to treat age-related macular degeneration and other retinal diseases in humans." In the new study, Sugita and senior author Masayo Takahashi, who leads the Laboratory for Retinal Regeneration at RIKEN, directly addressed this controversy, focusing on retinal pigment epithelial cells.

The researchers transplanted iPSC-derived retinal pigment epithelial cells generated from donor monkeys into the eyes of recipient monkeys. In some cases, the donors and recipients were immunologically matched, that is, their cells expressed the same major histocompatibility complex (MHC) proteins; in other cases, the grafts were mismatched, signaling to the immune system that a foreign substance was present in the body.

Source : QNA