The present invention embraces a RNA replicon that can be replicated by a replicase of alphavirus origin and comprises an open reading frame encoding a reprogramming factor. Such RNA replicons are useful for expressing a reprogramming factor in a cell, in particular a somatic cell. Cells engineered to express such reprogramming factors are useful in cell transplantation therapies.

The nuclear reprogramming of somatic cells with mRNA encoding reprogramming factors is shown to be greatly accelerated by activation of innate immune responses in the somatic cell. Methods of activating innate immunity include activation of PKR, of toll-like receptors, e.g. TLR3, etc. In some embodiments the mRNA provides the activator of innate immunity.

Described herein are reprogramming techniques allowing for production of mammary-derived iPSCs (m-iPSCs). The m-iPSCs described herein exhibit all the hallmarks of stem cell identity including round cluster, bright colony morphology, clonal expansion, and pluripotent marker expression (alkaline phosphatase expression, Oct-4, nanog, etc.) Further refined techniques allow for generation of m-iPSCs under essentially defined conditions.

The present invention relates to expressing RNA in cells and, in particular, enhancing viability of cells in which RNA is to be expressed. Specifically, the present invention provides methods for expressing RNA in cells comprising the steps of preventing engagement of IFN receptor by extracellular IFN and inhibiting intracellular IFN signalling in the cells. Thus, preventing engagement of IFN receptor by extracellular IFN and inhibiting intracellular IFN signalling in the cells allows repetitive transfer of RNA into the cells.

The present invention relates to methods for reprogramming a somatic cell to pluripotency by administering into the somatic cell at least one or a plurality of potency-determining factors. The invention also relates to pluripotent cell populations obtained using a reprogramming method.

The present invention relates to the production of avian induced pluripotent stem cells from non-pluripotent somatic cells, including embryonic fibroblasts and adult somatic cells. In this method, avian (including quail or chicken) somatic cells are reprogrammed into a state closely resembling embryonic stem cells including the expression of key stem cell markers alkaline phosphatase, etc. by transfecting/transducing the non-stem cells with genes (preferably using a non-integrating vector as otherwise described herein or alternatively an integrating vector, such a lentiviral vector, retroviral vector or inducible lentiviral vector, among others) which express at least nanog, Lin28 and cMyc. In preferred aspects of the invention, the transfected/transduced vectors express nanog, Lig28, cMyc, Oct 4 (POU5F1 or PouV), SOX2 and KLF4. The induced stem cells which are produced contribute to all 3 germ layers, the trophectoderm and in certain aspects, the gonad in chimeric offspring.

Embodiments herein relate to in vitro production methods of hematopoietic stem cell (HSC) and hematopoietic stem and progenitor cell (HSPC) that have long-term multilineage hematopoiesis potentials upon in vivo engraftment. The HSC and HSPCs are derived from pluripotent stem cells-derived hemogenic endothelia cells (HE) by non-integrative episomal vectors-based gene transfer.

A method of producing an induced pluripotent stem cell includes introducing into a somatic cell one or more non-viral expression vectors. The vectors include one or more of an Oct family gene, a Klf family gene, a Sox family gene, a Myc family gene, a Lin family gene, and Nanog gene. The somatic cell is then cultured in a medium that supports pluripotent stem cells. At least a portion of the one or more introduced non-viral expression vectors is not substantially integrated in the chromosome.

Disclosed are findings that: (a) induced pluripotent stem cells derived from aged donors (A-iPSC) show increased genomic instability, a defect in apoptosis, a defect in glucose metabolism, and a blunted DNA damage response are compared to those derived from young donors (Y-iPSC); and (b) inhibition of excessive glutathione-mediated H202 scavenging activity, found to be associated with A-iPSC and in turn inhibiting DNA damage response and apoptosis, substantially rescues these defects and reduces the oncogenic potential of A-iPSC. Supplementation of pluripotency factor ZSCAN 10 (shown to be poorly activated in A-iPSC and to act upstream of glutathione involvement), e.g., by expression as an adjunct to the four Yamanaka iPSC reprogramming factors, led to substantial recovery of genomic stability, DNA damage response, and apoptosis in A-iPSC through enhancing GLUT3 and normalizing homeostasis of glutathione/H202; GLUT3 (a pluripotent stem cell-specific glucose transporter acting upstream of glutathione and also poorly activated in A-iPSC) has similar effects, indicating that inhibition of glutathione/H202 notably through delivery of ZSCAN 10 and/or GLUT3 and/or an exosome subunit will be clinically useful, resulting in A-iPSC of improved properties and reduced oncogenic potential.

The present invention provides compositions and methods for reprogramming somatic cells using purified RNA preparations comprising single-strand mRNA encoding an iPS cell induction factor. The purified RNA preparations are preferably substantially free of RNA contaminant molecules that: i) would activate an immune response in the somatic cells, ii) would decrease expression of the single-stranded mRNA in the somatic cells, and/or iii) active RNA sensors in the somatic cells. In certain embodiments, the purified RNA preparations are substantially free of partial mRNAs, double-stranded RNAs, un-capped RNA molecules, and/or single-stranded run-on mRNAs.