The overall goal of this study was to develop new technologies to produce human pluripotent stem cell lines under conditions that are optimal for future clinical use. In the final year of this study, we used a new culture system validated in our lab in Years 1 and 2 of this grant to derive a human embryonic stem cell line and approximately 25 human induced pluripotent stem cell lines under conditions that are completely free of animal products, an important consideration for therapy. The cell lines derived under these conditions showed all the features expected of human pluripotent stem cell lines, demonstrating clear proof of concept for this approach.
In a second set of experiments, we addressed another roadblock to the use of induced pluripotent stem cells in research and therapy. Efficient, high throughput production of human induced pluripotent stem cells for the establishment of banks for tissue matching will require very efficient selection of fully reprogrammed cell lines. However, after reprogramming, only a small proportion of stem cell lines are truly pluripotent. We identified new cell surface markers that enable us to prospectively isolate colonies of stem cells that are fully reprogrammed to the pluripotent state.