A Novel Method for the Generation of Induced Pluripotent Stem Cells From Human Peripheral Blood

Background: In terms of the generation of induced pluripotent stem(iPS) cells, one of the important issues for clinical applications is cell source. Human peripheral blood is one of the easily accessible cell sources. However, isolated peripheral blood cells have shown low gene transfection efficiency and inconveniences requiring specific methods to isolate. Here, we report a novel population of peripheral blood-derived stem cells, which can be easily reprogrammed to iPS cells.Methods and Results: We cultured peripheral blood mononuclear cells (PBMC) from human peripheral blood and seeded on the fibronectin-coated plate. We observed adherent cells from as early as 5 days after the start of culture and those cells gradually formed colonies. We were able to isolate these cells with very high efficiency. Furthermore, we have also confirmed that these cells can be differentiated to osteogenic, adipogenic, and myogenic-lineage cells. Therefore, we named these cells circulating multipotent adult stem cell. We were successful in generating iPS cells with these cells. These cells showed enhanced efficiency of gene transduction, compared to the human dermal fibroblast. We obtained reprogrammed colonies in 8 days after 4 factor virus transduction without feeder cells. We identified our iPS cells had similar features to embryonic stem cell in morphology, gene expression, epigenetic state and ability to differentiate into the three germ layers. We obtained more than 46 iPS cell lines from PBMC of patients with cardiovascular disease and normal volunteers.Conclusions: Our study showed new methods to isolate stem cells from peripheral blood and to generate iPS cells with high efficacy. This result suggests that our new approach could be one of ideal methods for clinical application of iPS cells in future.