Mi Wang

© 2015 Elsevier Inc.The breakthrough of induced pluripotent stem cell technology has raised the possibility that patient-specific iPSCs may become a renewable source of autologous cells for cell therapy without the concern of immune rejection. However, the immunogenicity of autologous human iPSC -derived cells is not well understood. Using a humanized mouse model reconstituted with a functional human immune system, we demonstrate that most teratomas formed by autologous integration-free hiPSCs exhibit local infiltration of antigen-specific T cells and associated tissue necrosis, indicating immune rejection of certain hiPSC-derived cells. In this context, autologous hiPSC-derived smooth muscle cells appear to be highly immunogenic, while autologous hiPSC-derived retinal pigment epithelial cells are immune tolerated even in non-ocular locations. This differential immunogenicity is due in part to abnormal expression of immunogenic antigens in hiPSC-derived SMCs, but not in hiPSC-derived RPEs. These findings support the feasibility of developing hiPSC-derived RPEs for treating macular degeneration.

© 2015 American Physical Society.We present a systematic angle-resolved photoemission spectroscopy study of the substitution dependence of the electronic structure of Rb0.8Fe22, where superconductivity is continuously suppressed into a metallic phase. Going from the nonsuperconducting Rb0.8Fe2S2 to superconducting Rb0.8Fe2Se2, we observe little change of the Fermi surface topology, but a reduction of the overall bandwidth by a factor of 2. Hence, for these heavily electron-doped iron chalcogenides, we have identified electron correlation as explicitly manifested in the quasiparticle bandwidth to be the important tuning parameter for superconductivity, and that moderate correlation is essential to achieving high TC.