Transgenic stem cells replace skin

The treatment of a patient affected by an incurable genetic skin disease demonstrates the efficacy, feasibility and safety of replacing almost the whole skin using genetically corrected stem cells. See Letter p.327 Patients with junctional epidermolysis bullosa (JEB) carry mutations in genes that encode components of the basement membrane, which ensures the integrity between the epidermis and the dermis, such as laminin-332. These mutations cause blistering of the skin and chronic wounds. Following initial treatment of an adult patient with a limited affected region, Michele De Luca and colleagues reconstruct the full epidermis of a 7-year-old patient with autologous transgenic cells transduced with a virus vector carrying the non-mutated form of laminin-322. The integration sites of the virus used for gene delivery provide a tracing tool ex vivo and in vivo and demonstrate that the human epidermis is sustained by a limited number of long-lived stem cells.