Michele De Luca from the University of Modena, Italy and his collaborator Reggio Emilia have used a stem cell-based gene therapy to treat an inherited skin disorder.
Epidermolysis bullosa is a painful skin disorder that causes the skin to be very fragile and blister easily. These blisters can lead to life-threatening infections. Unfortunately, no cure exists for this condition and most treatments try to alleviate the symptoms and infections.
Stem cell-based therapy seems to be one of the best ways to treat this disease, there are no clinical studies that have examined the long-term outcomes of such a treatment.
However, De Luca and his colleagues have examined a particular patients with epidermolysis bullosa who was treated with a stem cell-based gene therapy nearly seven years ago as part of a clinical trial.
The treatment of this patient has established that transplantation of a small quantity of stem cells into the skin on this patient’s legs restored normal skin function without causing any adverse side effects.
“These findings pave the way for the future safe use of epidermal stem cells for combined cell and gene therapy of epidermolysis bullosa and other genetic skin diseases,” said Michele De Luca.
De Luca and his research team found that their treatment of their patient, named Claudio, caused the skin covering his upper legs to looker normal and show no signs of blisters. To treat Claudio, De Luca and his colleague extracted skin cells from Claudio’s palm, used genetic engineering techniques to correct the genetic defect in the cells, and then transplanted these cells back into the skin of his upper legs. This was part of a clinical trial conducted at the University of Modena.
Claudio’s legs also showed no signs of tumors and the small number of transplanted cells sufficiently repaired Claudio’s skin long-term. Keep in mind that Claudio’s skin cells had undergone approximately 80 cycles of cell division and still had many of the features of palm skin cells, they show proper elasticity and strength and did not blister.
“This finding suggests that adult stem cell primarily regenerate the tissue in which they normally reside, with little plasticity to regenerate other tissues,” De Luca said. “This calls into question the supposed plasticity of adult stem cells and highlights the need to carefully chose the right type of stem cell for therapeutic tissue regeneration.”
I think De Luca slightly overstates his case here. Certainly choosing the right stem cells is crucial for successful stem cell treatments, but to take stem cells from skin, which are dedicated to making skin and expect them to form other tissues is unreasonable. However, several experiments have shown that stem cells from hair follicles and form neural tissues and several other cell types as well (see Jaks V, Kasper M, Toftgård R. The hair follicle-a stem cell zoo. Exp Cell Res. 2010 May 1;316(8):1422-8).
Adult stem cells have limited plasticity to be sure, but their plasticity is far greater than originally thought and a wealth of experiments have established that.
Despite these quibbles, this is a remarkable experiment that illustrates the feasibility and safety of such a treatment. A larger problem is that large quantities of cells will be required to treat a person. It is doubtful that small skin biopsies around the body can provide enough cells to treat the whole person. Therefore, this might a case for induced pluripotent skin cells, which seriously complicates this treatment strategy.