We now can create critical cell types like cardiomyocytes etc. from stem cells. Additionally, we are learning the rules of using these cells to rebuild tissues. A major gap in our knowledge relates to the immunobiology of these cells. Lessons from transplantation medicine are only partially applicable, because solid organs are more complex and likely more immunogenic than defined cell populations.
How does the immune system respond to allogeneic cells like cardiomyocytes? If they are rejected, is this through class I or class II MHC? Cell-mediated or humoral immunity? How important are minor (non-MHC) antigens? What class of immunosuppressants are required to prevent rejection? How does this compare to whole-organ tranplants?