Year 1

Human induced pluripotent stem cells (hiPSCs), reprogrammed from somatic cells with defined factors, are similar to human ES cells (hESCs) and could provide ideal cell source for transplantation by avoiding immune rejection. In addition, disease-specific hiPSCs could provide improved disease models to predict drug responses in humans. The permanent genetic modification by random viral integration and spontaneous reactivation of reprogramming factors lead to cancer risk and abnormal differentiation. During the past year, we have made progresses to develop a combination of chemical and episomal approaches to reprogram human cells into iPSCs without genetic modifications. We have developed the constructs for the pre-transplant strategies to eliminate the teratomas risk of undifferentiated iPSCs. We have started to improve conditions for iPSC differentation into beta cells. In addition, we developed mouse models reconstituted with human immune system to enable us to study the immunogenicity and tolerance of cells derived from isogenic iPSCs.