Preclinical model for phenotypic correction of dystrophic epidermolysis bullosa by CRISPR-Cas9 delivery using adenoviral vectors.

Recessive dystrophic epidermolysis bullosa, a devastating skin fragility disease characterized by recurrent skin blistering, scarring, and a high risk of developing squamous cell carcinoma is caused by mutations in , the gene encoding type VII collagen, which is the major component of the anchoring fibrils that bind the dermis and epidermis. correction of by gene editing in patients' cells has been achieved before. However, editing approaches are necessary to address the direct treatment of the blistering lesions characteristic of this disease. We have now generated adenoviral vectors for CRISPR-Cas9 delivery to remove exon 80 of , which contains a highly prevalent frameshift mutation in Spanish patients. For testing, a humanized skin mouse model was used. Efficient viral transduction of skin was observed after excisional wounds generated with a surgical punch on regenerated patient skin grafts were filled with the adenoviral vectors embedded in a fibrin gel. Type VII collagen deposition in the basement membrane zone of the wounded areas treated with the vectors correlated with restoration of dermal-epidermal adhesion, demonstrating that recessive dystrophic epidermolysis bullosa (RDEB) patient skin lesions can be directly treated by CRISPR-Cas9 delivery .