5. Newly Developed Measles Virus Vector Can Simultaneously Transfer Multiple Genes Into Human Hematopoietic Cells and Induce Ground State Like Pluripotent Stem Cells

We reports newly developed virus vector, measles virus vector can transfer multiple genes into human hematopoietic cells effectively and induce ground state pluripotent stem cells from somatic cells without affecting the host genome.Measles virus (MV) which belongs to negative single strand RNA viruses has been known to have high affinity for human peripheral immune cells including monocytes, B cells and T cells. We recently have developed novel MV gene transfer vector which is non-transmissible, can transfer multiple genes simultaneously. The MV vector which carries 5 genes (GFP, human OCT3/4, SOX2, KLF4, and L-MYC) (MV-dF-OSKL-EGFP) could express these genes in various human cells with differential expression levels depending on the arrangement of the gene in the vector. Especially, MV-dF-OSKL-EGFP was able to transduce genes into more than 80% of hematopoietic cells besides natural killer cells. Naive and stem cell memory T cells were also transduced by MV-dF-OSKL-EGFP.These results indicated that the newly developed MV vector had the significant character as the new gene transfer vector compared with conventional viral gene transfer vectors including Sendai virus vector, which belongs to the same RNA virus vector.We could successfully generated induced pluripotent stem cells (iPS cells) from human fibroblasts or peripheral blood T cells using MV-dF-OSKL-EGFP. These iPS cells expressed the pluripotent markers of NANOG and Tra-1-60 and were demethylated. These iPS cells also differentiated into three germ line tissues in vitro and in vivo. Importantly, we also could establish the ground state like pluripotent cell (GSL-iPS cells) from hematopoietic cells by using MV-dF-OSKL-EGFP. In the presence of human leukemia inhibitory factor (LIF), GSK-3 inhibitor (CHIR99021), and MEK inhibitor (PD0325901), GSL-iPS cells were able to be cultured from a dissociated single cell with rapid cell growth. GSL-iPS cells also expressed pluripotent markers of NANOG and Tra-1-60, and were able to differentiate into three germ line cells. In conclusion, our newly developed MV vector may induce revolutional advance in the field of gene and cell therapy using iPS cells.