Because transplanted stem cells are seen by the human body as an unknown and potentially dangerous foreign organism, the immune system often kicks into high gear when cells are detected. That can lead to transplant rejection. While there are some drugs that help suppress the immune system's response, it also leaves the patient exposed to other diseases that can complicate matters. The modified stem cells created at UCSF present a potential solution to this problem by simply not setting off the immune system's alarms in the first place.
The UCSF discovery marks the first time engineered cells to survive inside their recipients without any sort of immune response. The process is done by using the powerful and occasionally controversial CRISPR technology to delete two genes, a major histocompatibility complex (MHC) class I and II that would typically signal to the immune system that a cell is foreign. The scientists then added CD47 and a cell protein that essentially tells the immune system not to destroy a cell.
The technique was tested on the mouse and proved to be a success, suggesting the process could also work on humans. The new process could significantly reduce the risks associated with stem cells and other transplants. That would open up new possibilities for procedures that save, extend and improve people's lives