Highly efficient gene transfer into primate embryonic stem cells with a simian lentivirus vector.

The ability to stably introduce genetic material into primate embryonic stem (ES) cells could allow their broader application. We previously derived ES cell lines from cynomolgus monkey blastocysts. In this study, we examined lentiviral gene transfer into cynomolgus ES cells. When cynomolgus ES cells were transduced once with a simian immunodeficiency virus (SIV)-based lentivirus vector encoding the green fluorescent protein (GFP) gene, most cells (around 90%) fluoresced, and high levels of GFP expression persisted for 5 months without selection procedures. In addition, high levels of GFP expression were observed during embryoid body formation. On the other hand, transduction of mouse ES cells with the SIV-based vector resulted in lower gene transfer rates, implying that SIV vectors can transduce primate ES cells more efficiently than mouse ES cells. The use of GFP as a reporter gene allows direct and simple detection of successfully transduced ES cells and facilitates monitoring of ES cell proliferation and differentiation both in vitro and potentially in vivo. Furthermore, this highly efficient gene transfer method allows faithful gene delivery to primate ES cells with potential for both research and therapeutic application.