Fooling the human immune system into accepting foreign transplant tissue as its own may be the key to future stem cell and organ transplants, say experts.The new technique could make tissue grafts invisible to the immune system, and would allow transplant recipients to circumvent the multiple side effects of immunosuppressive drugs, says Maggie Dallman, an immunologist at Imperial College London, UK, whose team is examining the method in mice.The process – which dupes the cells the human body uses to regulate its immunity – makes use of the natural immune-dampening effect of suppressor or regulatory T-cells. It has shown some promise in treating auto-immune diseases such as multiple sclerosis in mice. Regulatory T-cells keep other immune cells in check, and prevent them from attacking the body’s own tissues.Researchers have considered using stem cells to treat diseases such as Alzheimer’s, Parkinson’s and diabetes, as well as using them to replace or repair damaged organs. However, the transplant of stem cells not produced from the recipients own cells are likely to pose the same problems with tissue rejection as conventional organ transplants.
