Lack of immune response to differentiated cells derived from syngeneic induced pluripotent stem cells.

The prospects for using autologous induced pluripotent stem cells (iPSCs) in cell replacement therapy have been tempered by evidence that undifferentiated, syngeneic mouse iPSCs are immunogenic upon transplantation. However, the immunogenicity of more therapeutically relevant differentiated cells remains unexplored. Here, we differentiated mouse iPSCs into embryoid bodies (EBs) or representative cell types spanning the three embryonic germ layers and assessed their immunogenicity in vitro and after their transplantation into syngeneic recipients. We found no evidence of increased T cell proliferation in vitro, rejection of syngeneic iPSC-derived EBs/tissue-specific cells (TSCs) after transplantation, or an antigen-specific secondary immune response. Thus, differentiated cells derived from syngeneic iPSCs do not appear to be rejected after transplantation. We also found little evidence of an immune response to undifferentiated, syngeneic iPSCs. Our data support the idea that differentiated cells generated from autologous iPSCs could be applied for cell replacement therapy without eliciting immune rejection.