Base Editor Correction of COL7A1 in Recessive Dystrophic Epidermolysis Bullosa Patient-Derived Fibroblasts and iPSCs.

J Invest Dermatol
Authors
Abstract

Genome editing represents a promising strategy for the therapeutic correction of COL7A1 mutations that cause recessive dystrophic epidermolysis bullosa (RDEB). DNA cleavage followed by homology-directed repair (HDR) using an exogenous template has previously been used to correct COL7A1 mutations. HDR rates can be modest, and the double-strand DNA breaks that initiate HDR commonly result in accompanying undesired insertions and deletions (indels). To overcome these limitations, we applied an A•T→G•C adenine base editor (ABE) to correct two different COL7A1 mutations in primary fibroblasts derived from RDEB patients. ABE enabled higher COL7A1 correction efficiencies than previously reported HDR efforts. Moreover, ABE obviated the need for a repair template, and minimal indels or editing at off-target sites was detected. Base editing restored the endogenous type VII collagen expression and function in vitro. We also treated induced pluripotent stem cells (iPSCs) derived from RDEB fibroblasts with ABE. The edited iPSCs were differentiated into mesenchymal stromal cells, a cell population with therapeutic potential for RDEB. In a mouse teratoma model, the skin derived from ABE-treated iPSCs showed the proper deposition of C7 at the dermal-epidermal junction in vivo. These demonstrate that base editing provides an efficient and precise genome editing method for autologous cell engineering for RDEB.

Year of Publication
2020
Journal
J Invest Dermatol
Volume
140
Issue
2
Pages
338-347.e5
Date Published
2020 Feb
ISSN
1523-1747
DOI
10.1016/j.jid.2019.07.701
PubMed ID
31437443
PubMed Central ID
PMC6983342
Links
Grant list
RM1 HG009490 / HG / NHGRI NIH HHS / United States
R35 GM118062 / GM / NIGMS NIH HHS / United States
U01 AI142756 / AI / NIAID NIH HHS / United States
R01 HL056067 / HL / NHLBI NIH HHS / United States
R01 AR063070 / AR / NIAMS NIH HHS / United States