There has been much publicity recently regarding the potential for tissues grown in the laboratory from embryonic stem cells (ESC) or from induced pluripotent stem cells (iPSC) to be used to replace diseased or damaged tissue, but very little is known about whether such tissues would suffer rejection.
Our studies involve examining human iPSCs and ESCs, and their differentiated tissues, for expression of key molecules (including HLA antigens) involved in the immune response to transplantation, and then modelling their future use in patients by injecting them into mice. One of the mouse models that will give us a better understanding of how stem cells will function in humans is termed the “humanised mouse”. Humanised mice are simply immunodeficient mice that do not have a functional mouse immune system, but instead have a functional human immune system created by injecting them with human blood stem cells. Humanised mice will be able to reject human stem cell-derived tissues if, indeed, they are found to be immunogenic, and by studying their immune responses we will gain a better understanding of how to improve stem cell transplantation.