Generation of induced pluripotent stem cells from human cord blood using OCT4 and SOX2

Abstract

Mouse and human fibroblasts were the first cell types successfully reprog- rammed by ectopic expression of OCT4, SOX2, KLF4, and c-MYC (OSKM) (Lowry et al., 2008; Maherali et al., 2007; Park et al., 2008; Takahashi et al., 2007; Taka- hashi and Yamanaka, 2006; Yu et al., 2007). Further studies have shown that the age, origin, and cell type used have a deep impact on the reprogramming effi- ciency, eventually requiring the expres- sion of fewer factors and/or reducing the timing of the whole process. In general, stem cells are rare and difficult to access and isolate in large numbers (neural stem cells, for instance [Kim et al., 2008, 2009c]) and, therefore, represent a com- plicated target for reprogramming. How- ever, Cord Blood (CB) could represent an alternative and readily accessible source of stem cells. Here, we describe reprog- ramming of CB cells to pluripotency by retroviral transduction of four (OSKM), three (OSK), and as few as two (OS) tran- scription factors, without the need for additional chemical compounds.