Towards a gene therapy clinical trial for epidermolysis bullosa.

[junctional epidermolysis bullosa]

Genetic mutations affecting the capacity of basal keratinocytes to adhere firmly to the underneath derma lead to severe , often lethal , blistering disorders of the skin known as Epidermolysis Bullosa (EB ). About 400 ,000 -500 ,000 people worldwide are affected and no definitive treatments have yet been developed . Gene therapy might represent an alternative therapeutic approach for these devastating inherited disorders . In the last 10 years pre-clinical studies have shown that human epidermal stem cells can be stably transduced using integrating vectors allowing long -term genetic correction of the adhesion defects affecting EB keratinocytes both in vitro and in vivo after transplantation onto immunodeficient animals . In addition tremendous progress have been achieved in the clinical applications of cultured keratinocytes (cell therapy ) for the regeneration of the epidermis over full thickness wounds or the restoration of damaged corneal surfaces . The combination of (i ) optimised culturing conditions not altering the epidermal stemness , (ii ) gene transfer vectors able to target epidermal stem cells very efficiently and (iii ) surgical procedures allowing the grafting of large skin areas have therefore led our group to submit the first phase I /II gene therapy clinical trial for Junctional Epidermolysis Bullosa .