Human COL7A1-corrected induced pluripotent stem cells for the treatment of recessive dystrophic epidermolysis bullosa.

Epidermolysis bullosa (EB) is a family of inherited genetic blistering skin diseases. Children with one subtype lack a specific gene, called type VII collagen, develop a severe, scarring EB subtype, recessive dystrophic epidermolysis bullosa (RDEB). The lack of collagen VII results in the upper layers of the skin being only very loosely attached to the deeper layers of the skin resulting in painful blisters and wounds that cannot heal. The children typically die in their teens from infection, organ failure or skin cancer in the setting of these never-healing wounds. Patients with RDEB and other EB subtypes have been extensively diagnosed and treated here at Stanford for the past quarter century and, despite all efforts, current therapy for RDEB is limited to palliative wound care. In this paper we describe a novel approach to treat this devastating disease. We have shown that human induced pluripotent stem cells can be derived from EB patients, they can be gene-corrected in the culture dish, and subsequently turned into healthy skin cells. These genetically repaired, but still patient-derived skin cells can be grown into sheets of skin that we have shown can be transplanted onto the skin of immune-compromized mice. These human skin grafts showed long-term survival and restoration of the collagen VII. This work is a proof-of-principle that iPS cell reprogramming is a viable approach for clinical application