CRISPR-Cas9 gene-editing system has made pluripotent stem cells that are functionally “invisible” to the immune system which will prevent rejection of stem cell transplants. Universal stem cells can be produced that will work for everyone and there will not be the need for personalized stem cells. This will bring mass production of stem cells for regenerative medicine.
The immune system is unforgiving. It’s programmed to eradicate anything it perceives as alien, which protects the body against infectious agents and other invaders that could wreak havoc if given free rein. But this also means that transplanted organs, tissues or cells are seen as a potentially dangerous foreign incursion, which invariably provokes a vigorous immune response leading to transplant rejection.
Drugs are currently used to suppress the immune system, but this makes the patient vulnerable to other diseases and problems.
In the new work, three genes were altered. The stem cells were able to avoid rejection after being transplanted into histocompatibility-mismatched recipients with fully functional immune systems.
Nature Biotechnology – Hypoimmunogenic derivatives of induced pluripotent stem cells evade immune rejection in fully immunocompetent allogeneic recipients
Autologous induced pluripotent stem cells (iPSCs) constitute an unlimited cell source for patient-specific cell-based organ repair strategies. However, their generation and subsequent differentiation into specific cells or tissues entail cell line-specific manufacturing challenges and form a lengthy process that precludes acute treatment modalities. These shortcomings could be overcome by using prefabricated allogeneic cell or tissue products, but the vigorous immune response against histo-incompatible cells has prevented the successful implementation of this approach. Here we show that both mouse and human iPSCs lose their immunogenicity when major histocompatibility complex (MHC) class I and II genes are inactivated and CD47 is over-expressed. These hypoimmunogenic iPSCs retain their pluripotent stem cell potential and differentiation capacity. Endothelial cells, smooth muscle cells, and cardiomyocytes derived from hypoimmunogenic mouse or human iPSCs reliably evade immune rejection in fully MHC-mismatched allogeneic recipients and survive long-term without the use of immunosuppression. These findings suggest that hypoimmunogenic cell grafts can be engineered for universal transplantation.
SOURCES- UCSF, Nature Biotechnology, Tobias Deuse
Written By Brian Wang, Nextbigfuture.com