Establishment of integration-free induced pluripotent stem cells from human recessive dystrophic epidermolysis bullosa keratinocytes

Background: Induced pluripotent stem cell (iPSC) technology enables patient-specific pluripotent stem cells to be derived from adult somatic cells without the use of an embryonic cell source. To date, recessive dystrophic epidermolysis bullosa (RDEB)-specific iPSCs have been generated from patients using integrating retroviral vectors. However, vector integration into the host genome can endanger the biosafety and differentiation propensities of iPSCs. Although various integration-free reprogramming systems have been reported, their utility in reprogramming somatic cells from patients remains largely undetermined. Objective: Our study aims to establish safe iPSCs from keratinocytes of RDEB patients using non integration vector. Method: We optimized and infected non-integrating Sendai viral vectors to reprogram keratinocytes from healthy volunteers and RDEB patients. Results: Sendai vector infection led to the reproducible generation of genomic modification-free iPSCs from these keratinocytes, which was proved by immunohistochemistry, reverse transcription polymerase chain reaction, methylation assay, teratoma assay and embryoid body formation assay. Furthermore, we confirmed that these iPSCs have the potential to differentiate into dermal fibroblasts and epidermal keratinocytes. Conclusion: This is the first report to prove that the Sendai vector system facilitates the reliable reprogramming of patient keratinocytes into transgene-free iPSCs, providing another pluripotent platform for personalized diagnostic and therapeutic approaches to RDEB. (C) 2017 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.