Patent ID: 9328332
Filing Date: 2016-05-03
CPC Classification: C07K,C12N

Claim Text:
1. A method of producing human induced pluripotent stem (iPS) cells that are essentially free of differentiation programming vector genetic elements, the method comprising the steps of: a) obtaining a starting population of human somatic cells; b) obtaining one or more iPS Epstein-Barr virus (EBV)-based reprogramming vectors comprising a replication origin and one or more expression cassettes encoding iPS reprogramming factors comprising at least Sox-2, Oct-4, wherein one or more of said expression cassettes comprise a nucleotide sequence encoding a trans-acting factor that binds to the replication origin to replicate an extra-chromosomal template, and/or wherein cells of the starting population express such a trans-acting factor; c) introducing the iPS reprogramming vector(s) into the human somatic cells; d) culturing the human somatic cells that comprise the iPS EBV-based reprogramming vector(s) to effect expression of said reprogramming factors such that traits consistent with embryonic stem cells arise in at least a portion of cells in the cultured cells; and e) further culturing cells having the embryonic stem cell traits for a sufficient number of generations in the absence of positive selection for the presence of the iPS reprogramming vector(s) to provide human iPS cells that are essentially free of iPS reprogramming vector genetic elements.