Principles of stem cell biology and cancer: future applications and therapeutics. Edited by T. Regad, T. J. Sayers and R. C. Rees. John Wiley & Sons (2015)
1. Isolation and characterization of human embryonic stem cells and future applications in tissue engineering therapies
1.4. Future applications in tissue-engineering therapies
One of the greatest challenges facing any kind of cell-replacement therapy is the response of the host’s own immune system to a graft. Immune reactions to grafts and graft-versus-host disease (GVHD) can be so severe as to not only render the transplant useless but also kill the patient. In some cases, immunosuppressant drugs originally developed for organ transplantation can circumvent this, but these can produce their own complications. The intricate play between host and graft has been widely studied since the advent of hematopoietic stem cell transplantations. While engraftment of many cell types can strongly benefit from a limited host immune response, it must be considered that residual host response in allogeneic transplantation might also have applications in therapies.
The advent of cellular reprogramming holds the potential to make allogeneic transplants a thing of the past, circumventing the issue of immunerejection altogether. By taking a small skin biopsy or blood sample, it is now possible to create patient-specific iPSCs that can be used in place of hESCs in all of the aforementioned examples of tissue engineering. Derivatives of such reprogrammed cells will be a perfectly immune-compatible match to a host system, and considered as the host’s ‘own’ cells. It is of note that this will deprive the host of any means of immune detection, should such cells carry abnormalities that could cause cancer.