Researchers believe that stem cells may be important for treating many eye diseases that are currently considered incurable. The biggest hurdle that they face when developing new stem cell therapies is safely transplanting cells into a patient’s eye without stem cell rejection.
Two recent studies published in the September 15 issue of the medical journal Stem Cells the journal of the International Society for Stem Cell Research (ISSCR), indicate that scientists may have developed a method for successfully avoiding stem cell rejection.
In one of the studies, Japanese scientists successfully transplanted stem cell-derived retinal cells from immunologically matched donor animals without the use of immunosuppressants. Immunosuppressants are usually required so the recipient’s body does not reject the stem cells it has received.
One of the authors of the paper, Dr. Sunao Sugita, describes the breakthrough saying: “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,” he continued, “This approach could potentially be used to treat age-related macular degeneration and other retinal diseases in humans.”
The research project used a special type of stem cell called induced pluripotent stem cells (iPSCs). These cells are genetically reprogrammed skin cells taken from adult donors. The skin cells are reverted to an embryonic stem cell-like state, then can be prompted into turning into other types of cells.
iPSCs are particularly useful because they can transform into many types of cells and there is no risk of rejection when a person receives iPSCs derived from their own body.
This new research used iPSCs generated from one subject, transplanting them into an immunologically-matched recipient. They first created iPSCs, then prompted them to turn into retinal pigment epithelial cells. These cells were successfully transplanted into another monkey without the need for immunosuppressants.
The findings could lead to new treatments that have a much lower risk of stem cell rejection.
Source: Immune-matched stem cells prevent rejection of retinal transplants in animals
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