Grant Award Details
- To develop new methods to inactivate NK cell allo-reactivity to facilitate transplantation of stem cell derived tissue, in particular, to render a patient's NK cells tolerant to allogeneic HSC grafts.
Grant Application Details
- Inactivating NK cell reactivity to facilitate transplantation of stem cell derived tissue
One of the great promises of stem cell research is that it will one day be possible to prepare replacement cells or organs from stem cells such as embryonic stem cells, which can be transplanted to patients to substitute for diseased or defective patient tissues or organs. Unfortunately, the immune system reacts against, and rejects, transplanted tissues that are not perfectly matched with the recipient. A promising approach around this problem is a two step procedure, in which a patient is first transplanted with blood stem cells of a specific type, and later with replacement tissues or cells derived from the same embryonic stem cells as the blood stem cells. If the blood cell transplant is successful, the patient’s blood cells will forever after be composed of a mixture of their own blood cells and the donor blood cells (“chimerism”). It is known that blood cell chimerism induces the recipient to be accept diverse types of grafts of the same source as the blood cells. Thus, the blood cell graft prepares the recipient to accept other types of grafts derived from the same stem cells. Unfortunately, blood stem cell grafts are themselves subject to a specific type of immune rejection, mediated by natural killer (NK) cells. Hence, successful application of the two step procedure requires the development of methods to prevent NK cells from rejecting blood cell grafts.
We have developed evidence that NK cells can be induced to become tolerant of mismatched blood cell grafts. We propose studies to develop a general procedure to induce tolerance of a recipient’s NK cells to mismatched blood cell grafts. Using an experimental model, we will test whether the procedure facilitates transplantation of blood cells derived from embryonic stem cells, the generation of blood cell chimerism, and the subsequent transplantation of other tissues in a two step procedure.
The proposed research is designed to provide novel methods to facilitate therapeutic transplantation of stem cell derived cells and tissues to patient’s suffering from numerous disorders and diseases. Such approaches will ultimately benefit millions of Californians suffering from diabetes, heart disease, neurodegenerative diseases, etc. Breakthroughs in stem cell research in California will also generate new industries, reducing joblessness and bolstering the California economy.