Since iPS cells can be transformed into various types of cells, they are expected to be applied to transplantation medicine.However, when transplanting iPS cells derived from another person, rejection may occur due to the immune cells of the transplanted patient, as in normal transplantation medicine.To reduce this risk, transplantation using iPS cells in a combination of leukocyte types that are less likely to cause rejection has been planned, but it was unclear what kind of immune response would occur and to what extent.

　The research group conducted mouse skin graft experiments assuming transplantation using iPS cells.As a result, it was found that in leukocyte-type matching transplantation, the time until the graft is rejected may be extended or the graft may be rejected at an early stage.In addition, analysis of the immune response that can occur during transplantation showed the infiltration of immune cells into the transplant and the reaction of T cells, which are a type of immune cells.Furthermore, no antibody was produced that contributed to the rejection even in the combination in which the graft was rejected at an early stage.Since it is very difficult to control rejection by antibodies, leukocyte-type matching transplantation has a great advantage in this respect.

　Furthermore, the effectiveness of immunosuppressants was also verified.There were transplant combinations that could suppress rejection for a long period of time, but in some cases the graft was rejected even with the use of immunosuppressive agents.These results indicate the importance of post-transplant immune response control even in regenerative medicine using iPS cells.In the future, it is expected that research using this transplantation model will progress in order to develop an appropriate method for controlling the immune response.

Paper information:[Scientific Reports] Establishment of an experimental model for MHC homo-to-hetero transplantation