Abstract: The generation of induced Pluripotent Stem Cells (iPSCs) enable people to have the opportunity to use patient-specific somatic cells which radically advance the field of regenerative medicine including disease modeling and drug discovery. The use of lentiviruses in the process of reprogramming human somatic cells into induced Pluripotent Stem (iPS) cells could produce tumorigenic insertional mutations and residual or reactivation of transgene expression during iPSC differentiation which could limit their therapeutic usefulness and affect lineage choice and the unctionality of iPSC derivatives. In addition, the exposure of iPSCs to animal-derived products may cause potential xenopathogenic transmission and immune rejection, these problems should be avoided and urgently needed to be resolved before the clinical application. Here, researchers report a practical protocol enabling efficient iPSC induction from Human Adult Dermal Fibroblasts cells (HADFs) under xeno-free, virus-free, condition and without oncogene c-MYC using a combination of plasmids encoding OCT3/4, SOX2, KLF4, L-MYC, LIN28 and shRNA for TP53. Using the approach described in this study, researchers can generated 20 hiPS cell clones from 2x105 Human Adult Dermal Fibroblasts cells (HADFs). Meanwhile, researchers developed a culture system in which human vitronectin, a secreted glycoprotein that is rich in the extracellular matrix and blood, replaced conventionally used mouse feeder cells to generate iPS cells, we not only can maintain the long-term culture of iPSCs but also efficiently generate xeno-free iPSCs using vitronectin as an extracellular matrix, this induction method will promote the derivation of patient-specific integration-free and xeno-free iPSCs and would also be very useful to generation the clinical-grade iPSCs in the future.
Wentao Hu, Qiuyue Yan, Yu Fang, Zhandong Qiu and Suming Zhang, 2013. Generation of Human Induced Pluripotent Stem Cells with Non-Integrating Episomal Vectors and Xeno-Free Culture System. Journal of Animal and Veterinary Advances, 12: 1114-1122.