Targeted gene editing and near-universal cDNA insertion of CYBA and CYBB as a treatment for chronic granulomatous disease

ABSTRACT: Chronic granulomatous disease (CGD) is a severe inborn error of immunity (IEI) caused by defects in the NADPH oxidase. The best current treatment option for patients with CGD, allogeneic hematopoietic stem cell (HSC) transplantation, is associated with severe adverse effects such as graft-versus-host disease, highlighting a need for improved treatment options based on transplantation of autologous ex vivo gene-edited HSCs. Here, we generate CRISPR/Cas9-based gene editing strategies for the correction of two CGD-causing variants; CYBA c.287+1G>T (p22phox) causing autosomal CGD and CYBB c.252G>A (NOX2) causing X-linked CGD. We find that rAAV6 outperforms ssODNs and IDLVs as HDR repair templates in CD34+ hematopoietic stem and progenitor cells (HSPCs), and we optimize gene editing strategies further by including mRNA-encoded inhibitors/effectors. In addition, we develop a near-universal gene editing strategy for X-CGD by targeted integration of a truncated CYBB cDNA, covering 86% of X-CGD patients, and show functional ROS production in edited cells. We find prevalent off-target editing and chromosomal translocations that severely decreased the ability of gene edited HSPCs to engraft in immunodeficient mice, however, by limiting off-target editing through the use of a high-fidelity Cas9, we can show that we can substantially rescue the multilineage engraftment potential of the gene edited HSPCs. To further improve safety, we finally we develop a novel paired D10A Cas9n gene editing approach targeting CYBB. We demonstrate that using this D10A Cas9 approach, we can retain high on-target efficacy while we do not detect any off-target editing or translocations between on- or off-target cleavage sites. Collectively, we bring new insights into to safety and off-target effects of gene editing approaches targeting CYBA and CYBB, highlighting key challenges of these approaches while offering a potentially curative D10A Cas9n-based treatment option for patients with CGD with improved safety.

ORGANISM(S): Homo sapiens

PROVIDER: GSE287370 | GEO | 2025/02/24

REPOSITORIES: GEO