Optimising gene-editing strategies for recessive dystrophic epidermolysis bullosaOngoing
|Project lead||Ganna Bilousova Ph.D.|
|Organisation||University of Colorado Denver|
|Project budget||USD 330,000.00|
|Start date / Duration||01. Feb 2021 / 36 months|
|Funder(s) / Co-Funder(s)||DEBRA Austria, MSAP/EBEP Recommended|
|Research area||Cellular therapy|
Short lay summary
No effective therapies are available for recessive dystrophic epidermolysis bullosa (RDEB). Reprogramming adult cells into immature cells, called induced pluripotent stem cells (iPSCs), may allow for the development of new therapies for RDEB. Specifically, iPSCs generated from a RDEB patient can be genetically corrected and differentiated into new skin cells to be transplanted to the same patient. To reduce the complexity of an iPSC-based therapy, we have recently combined genetic editing of RDEB skin cells and their reprogramming into iPSCs into a one-step procedure. In this project, we will improve the efficiency of genetic correction of RDEB mutations in our one-step procedure. We will also adapt our simultaneous gene editing/reprogramming approach to cells derived from urine specimens to provide an alternative non-invasive source of somatic cells for RDEB therapy. If successful, this study will accelerate the clinical translation of an iPSC-based therapy for RDEB and other forms of EB.
Induced Pluripotent Stem Cells (iPSCs) hold great promise for medicine due to their unlimited proliferation capacity and their ability to differentiate into many cell types for cell replacement therapy. The ability to produce induced pluripotent stem cells (iPSCs) also offers the possibility of developing a permanent corrective therapy for recessive dystrophic epidermolysis bullosa (RDEB). The potential iPSC-based therapy for RDEB involves multiple steps (reprogramming, gene correction, iPSC differentiation) with lengthy cell culture periods associated with each of these steps (usually several months), resulting in an increased risk of mutation accumulation and karyotype instability in the final cell product. To reduce the complexity of developing iPSC-based therapies, we have recently combined CRISPR/Cas9-mediated gene editing of RDEB fibroblasts with our RNA-based reprogramming approach into a one-step procedure. Here, we propose to improve the efficiency and specificity of COL7A1 correction in our simultaneous gene editing/reprogramming approach to reduce off-target events. We also propose to adapt our simultaneous gene editing/reprogramming approach to another cell type, urine-derived renal epithelial cells (RECs), as an alternative non-invasive source of somatic cells for developing an iPSC-based therapy. The isolation of fibroblasts requires a skin biopsy, which is an invasive procedure commonly associated with scarring and inflammation. In addition, due to continuous inflammation in the skin, RDEB fibroblasts may acquire additional mutations, reducing the safety of these cells for clinical applications. Therefore, another type of somatic cells suitable for gene editing and reprogramming, such as urine-derived RECs, may prove to be safer and more efficient for the iPSC-based therapy than fibroblasts. Thus, if successful, the proposed study will make our one-step gene editing and reprogramming technology more efficient and significantly safer and will accelerate the translation of an iPSC-based therapy for RDEB and other types of EB into the clinic.
If successful, our proposal will make our simultaneous gene editing and reprogramming approach significantly safer and more straightforward, accelerating the clinical translation of an iPSC-based therapy for RDEB and other forms of EB. In addition, our study may provide a foundation for improving Cas9-mediated genetic correction of EB-associated mutations in somatic cells.