Induced pluripotent stem cells (iPSCs) have great potential in regenerative medicine; however, the genetic reprogramming needed to produce these cells has left questions about their possible immunogenicity. In Nature, Abe and colleagues provide strong evidence suggesting that the ten iPSC lines they examine show minimal signs of immunogenicity. The authors use iPSCs derived from C57BL/6 mice to generate highly chimeric mice in which both the skin epithelium and bone marrow arise from differentiated iPSCs. After transplantion into syngeneic hosts, iPSC-derived skin or bone marrow shows little if any evidence of rejection and is essentially tolerated as well as embryonic stem cell–derived tissues. Bone marrow cells that arise from iPSCs can also reconstitute lethally irradiated hosts and thus seem to be functionally normal. These findings could allay fears about one of the main potential impediments to the clinical use of iPSCs.

Nature 494, 100–104 (2013)