[Show abstract][Hide abstract] ABSTRACT: The continuous renewal of human epidermis is sustained by stem cells contained in the epidermal basal layer and in hair follicles. Cultured keratinocyte stem cells, known as holoclones, generate sheets of epithelium used to restore severe skin, mucosal and corneal defects. Mutations in genes encoding the basement membrane component laminin 5 (LAM5) cause junctional epidermolysis bullosa (JEB), a devastating and often fatal skin adhesion disorder. Epidermal stem cells from an adult patient affected by LAM5-beta3-deficient JEB were transduced with a retroviral vector expressing LAMB3 cDNA (encoding LAM5-beta3), and used to prepare genetically corrected cultured epidermal grafts. Nine grafts were transplanted onto surgically prepared regions of the patient's legs. Engraftment was complete after 8 d. Synthesis and proper assembly of normal levels of functional LAM5 were observed, together with the development of a firmly adherent epidermis that remained stable for the duration of the follow-up (1 year) in the absence of blisters, infections, inflammation or immune response. Retroviral integration site analysis indicated that the regenerated epidermis is maintained by a defined repertoire of transduced stem cells. These data show that ex vivo gene therapy of JEB is feasible and leads to full functional correction of the disease.
Nature Medicine 01/2007; 12(12):1397-402. · 22.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mutations in genes encoding the laminin-5 heterotrimer, a key component of the epidermal-dermal junction, cause junctional epidermolysis bullosa (JEB), a severe and often fatal skin adhesion defect. Epidermal stem cells isolated from patients affected by β3 chain-deficient JEB were transduced with a retroviral vector expressing a β3 cDNA, and used to generate uniformly transduced cultured skin implants. The transgene was steadily expressed for >160 cell doublings in culture, leading to restoration of normal laminin 5 levels, assembly of functional hemidesmosomes, and full phenotypic correction. Cloning and sequencing of vector integrations showed that
[Show abstract][Hide abstract] ABSTRACT: To optimize melanocyte/keratinocyte co-cultivation and to evaluate the effectiveness of autologous cultured epidermal grafts in the surgical treatment of stable vitiligo.
After optimization of melanocyte/keratinocyte cultures, achromic lesions were disepithelialized by means of programmed diathermosurgery (Timedsurgery) and covered with autologous epidermal grafts prepared from secondary cultures. Melanocyte content was evaluated by dopa reaction. The percentage of repigmentation was calculated using a semiautomatic image analysis system.
A biosafety level 3 cell culture facility and a dermatological department in a hospital.
Thirty-two patients carrying different types of vitiligo were admitted to the study and treated with autologous cultured epidermal grafts. Inclusion criteria were (1) failure of at least 2 standard medical approaches; (2) no therapy for at least 12 months; (3) absence of progression of old lesions, absence of appearance of new lesions, and absence of Koebner phenomenon within the past 18 months; and (4) absence of autoimmune disorders.
One hundred five achromic lesions (a total of 6078.2 cm(2)) were treated. The average percentage of repigmentation, evaluated after 12 to 36 months of follow-up, was 77%. Independent of the type of vitiligo, average percentages of repigmentation of extremities and periorificial sites were 8% (31.8 cm(2) repigmented/420.5 cm(2) transplanted) and 35% (17.6 cm(2) repigmented/50.0 cm(2) transplanted), respectively. Percentages of repigmentation of all other body sites ranged from 88% to 96% (4329.7 cm(2) repigmented/4675.2 cm(2) transplanted). Color matching was good and scar formation was not observed.
Cultured epidermal grafts can be considered a real therapeutic surgical alternative for "stable" but not lip-tip vitiligo.
Archives of Dermatology 12/2000; 136(11):1380-9. · 4.79 Impact Factor