Donor insertion into CX3CR1 allows epigenetic modulation of a constitutive promoter on hematopoietic stem cells and its activation upon myeloid differentiation.

ABSTRACT: To improve ex vivo gene therapy strategies involving hematopoietic stem and progenitor cells (HSPCs), we propose a novel knock-in strategy (named KI-Ep) aiming to achieve transgene regulation of the inserted cassette through the acquisition of naturally occurring epigenetic marks. Based on this hypothesis, we selected CX3CR1 (a myeloid-specific gene presenting a poised histone signature on primitive HSPCs) as safe harbor to generate KI-Ep HSPCs. We demonstrated that, unlike the expression pattern achieved with lentiviral vectors (LVs), the insertion of a constitutive expression cassette into the intron 1 of the CX3CR1 locus (CX3CR1-I) in HSPCs resulted in very low expression levels in the more primitive HSPCs but, crucially, strong expression in HSPC-differentiated populations (especially

SUBMITTER: Ramos-Hernandez I 

PROVIDER: S-EPMC12038399 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature