CRISPR-based gene editing enables FOXP3 gene repair in IPEX patient cells.

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Publication Year:
2020
Authors:
PubMed ID:
32494707
Public Summary:
IPEX syndrome is a severe pediatric disease with limited treatment options. It is caused by mutations in the gene that encodes the protein, FOXP3. FOXP3 is an important gene in specific immune cells called T regulatory cells (Tregs); without functioning FOXP3 protein, Tregs cannot perform their normal immune regulatory functions. As a disease caused by mutation of a single protein, IPEX is an ideal candidate for a therapeutic approach in which the patients own stem cells or T cells are harvested, then engineered to express a wild type copy of the FOXP3 gene, and returned to the patient. Here we describe a successful CRISPR based gene correction strategy in which we restore FOXP3 gene expression in stem cells and T cells. Importantly, we demonstrate that this strategy works in both donor healthy cells as well as cells from IPEX patients. These results confirm the feasibility of gene correction, which will be instrumental for the development of therapeutic approaches for IPEX syndrome, as well as other genetic autoimmune diseases.
Scientific Abstract:
The prototypical genetic autoimmune disease is immune dysregulation polyendocrinopathy enteropathy X-linked (IPEX) syndrome, a severe pediatric disease with limited treatment options. IPEX syndrome is caused by mutations in the forkhead box protein 3 (FOXP3) gene, which plays a critical role in immune regulation. As a monogenic disease, IPEX is an ideal candidate for a therapeutic approach in which autologous hematopoietic stem and progenitor (HSPC) cells or T cells are gene edited ex vivo and reinfused. Here, we describe a CRISPR-based gene correction permitting regulated expression of FOXP3 protein. We demonstrate that gene editing preserves HSPC differentiation potential, and that edited regulatory and effector T cells maintain their in vitro phenotype and function. Additionally, we show that this strategy is suitable for IPEX patient cells with diverse mutations. These results demonstrate the feasibility of gene correction, which will be instrumental for the development of therapeutic approaches for other genetic autoimmune diseases.